Interconnect Analysis Program Tutorialjmbussat/Physics290E/Fall-2006/... · Loading an Interconnect...

RaphaelTM

Interconnect Analysis Program

TutorialVersion Y-2006.03, March 2006

ii

Copyright Notice and Proprietary InformationCopyright © 2006 Synopsys, Inc. All rights reserved. This software and documentation contain confidential and proprietary information that is the property of Synopsys, Inc. The software and documentation are furnished under a license agreement and may be used or copied only in accordance with the terms of the license agreement. No part of the software and documentation may be reproduced, transmitted, or translated, in any form or by any means, electronic, mechanical, manual, optical, or otherwise, without prior written permission of Synopsys, Inc., or as expressly provided by the license agreement.

Right to Copy DocumentationThe license agreement with Synopsys permits licensee to make copies of the documentation for its internal use only. Each copy shall include all copyrights, trademarks, service marks, and proprietary rights notices, if any. Licensee must assign sequential numbers to all copies. These copies shall contain the following legend on the cover page:

“This document is duplicated with the permission of Synopsys, Inc., for the exclusive use of __________________________________________ and its employees. This is copy number __________.”

Destination Control StatementAll technical data contained in this publication is subject to the export control laws of the United States of America. Disclosure to nationals of other countries contrary to United States law is prohibited. It is the reader’s responsibility to determine the applicable regulations and to comply with them.

DisclaimerSYNOPSYS, INC., AND ITS LICENSORS MAKE NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARD TO THIS MATERIAL, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

Registered Trademarks (®)Synopsys, AMPS, Arcadia, C Level Design, C2HDL, C2V, C2VHDL, Cadabra, Calaveras Algorithm, CATS, CRITIC, CSim, Design Compiler, DesignPower, DesignWare, EPIC, Formality, HSIM, HSPICE, Hypermodel, iN-Phase, in-Sync, Leda, MAST, Meta, Meta-Software, ModelTools, NanoSim, OpenVera, PathMill, Photolynx, Physical Compiler, PowerMill, PrimeTime, RailMill, RapidScript, Saber, SiVL, SNUG, SolvNet, Superlog, System Compiler, TetraMAX, TimeMill, TMA, VCS, Vera, and Virtual Stepper are registered trademarks of Synopsys, Inc.

Trademarks (™)Active Parasitics, AFGen, Apollo, Apollo II, Apollo-DPII, Apollo-GA, ApolloGAII, Astro, Astro-Rail, Astro-Xtalk, Aurora, AvanTestchip, AvanWaves, BCView, Behavioral Compiler, BOA, BRT, Cedar, ChipPlanner, Circuit Analysis, Columbia, Columbia-CE, Comet 3D, Cosmos, CosmosEnterprise, CosmosLE, CosmosScope, CosmosSE, Cyclelink, Davinci, DC Expert, DC Professional, DC Ultra, DC Ultra Plus, Design Advisor, Design Analyzer, Design Vision, DesignerHDL, DesignTime, DFM-Workbench, Direct RTL, Direct Silicon Access, Discovery, DW8051, DWPCI, Dynamic-Macromodeling, Dynamic Model Switcher, ECL Compiler, ECO Compiler, EDAnavigator, Encore, Encore PQ, Evaccess, ExpressModel, Floorplan Manager, Formal Model Checker, FoundryModel, FPGA Compiler II, FPGA Express, Frame Compiler, Galaxy, Gatran, HANEX, HDL Advisor, HDL Compiler, Hercules, Hercules-Explorer, Hercules-II,

Hierarchical Optimization Technology, High Performance Option, HotPlace, HSIMplus

, HSPICE-Link, iN-Tandem, Integrator, Interactive Waveform Viewer, i-Virtual Stepper, Jupiter, Jupiter-DP, JupiterXT, JupiterXT-ASIC, JVXtreme, Liberty, Libra-Passport, Library Compiler, Libra-Visa, Magellan, Mars, Mars-Rail, Mars-Xtalk, Medici, Metacapture, Metacircuit, Metamanager, Metamixsim, Milkyway, ModelSource, Module Compiler, MS-3200, MS-3400, Nova Product Family, Nova-ExploreRTL, Nova-Trans, Nova-VeriLint, Nova-VHDLlint, Optimum Silicon, Orion_ec, Parasitic View, Passport, Planet, Planet-PL, Planet-RTL, Polaris, Polaris-CBS, Polaris-MT, Power Compiler, PowerCODE, PowerGate, ProFPGA, ProGen, Prospector, Protocol Compiler, PSMGen, Raphael, Raphael-NES, RoadRunner, RTL Analyzer, Saturn, ScanBand, Schematic Compiler, Scirocco, Scirocco-i, Shadow Debugger, Silicon Blueprint, Silicon Early Access, SinglePass-SoC, Smart Extraction, SmartLicense, SmartModel Library, Softwire, Source-Level Design, Star, Star-DC, Star-MS, Star-MTB, Star-Power, Star-Rail, Star-RC, Star-RCXT, Star-Sim, Star-SimXT, Star-Time, Star-XP, SWIFT, Taurus, TimeSlice, TimeTracker, Timing Annotator, TopoPlace, TopoRoute, Trace-On-Demand, True-Hspice, TSUPREM-4, TymeWare, VCS Express, VCSi, Venus, Verification Portal, VFormal, VHDL Compiler, VHDL System Simulator, VirSim, and VMC are trademarks of Synopsys, Inc.

Service Marks (SM)MAP-in, SVP Café, and TAP-in are service marks of Synopsys, Inc.

SystemC is a trademark of the Open SystemC Initiative and is used under license.ARM and AMBA are registered trademarks of ARM Limited.All other product or company names may be trademarks of their respective owners.

Table of Contents

CONTENTS

Co

nten

ts

About This Manual xiii

Audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiiiRelated Publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiiiConventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xivCustomer Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiv

Accessing SolvNet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiv

Chapter 1 Getting Started 1-1Raphael Directory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1Raphael Parasitics Database Creation. . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1LPE Tools Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2Starting Raphael . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2Understanding the Raphael Main Window. . . . . . . . . . . . . . . . . . . . . . . 1-3

Parasitics Database and LPE Tools Interface Module . . . . . . . . . . . . 1-3Field Solvers Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4Interconnect Library. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4Taurus Layout and Net Extraction System . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

GUI Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4Mouse Button. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4Window Buttons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5Menus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5Keyboard Accelerators. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

Chapter 2 Interconnect Parasitics Extraction: Entire Flow 2-1Raphael Flow to Extract Interconnect Parasitics . . . . . . . . . . . . . . . . . . 2-1

Building a Parasitics Database. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1Generating a LPE Rule Deck with Capacitance Models . . . . . . . . . . 2-2

Draft 2/6/06RA 2006.03 iii

Table of Contents Raphael Tutorial

Chapter 3 Creating a Parasitics Database 3-1Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1Raphael Parasitics Database Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Sample Databases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2Defining Pathnames in the Database Directory . . . . . . . . . . . . . . . . . 3-3Selecting a New Database Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4Defining Technology Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . 3-5

Simulation and Regression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5Fully Automatic Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5

Previewing Structures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6Manual Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7

Generating Capacitance Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7Invoking LPE Tools Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7Menu Bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9

File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-9Edit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-9

Deleting a Database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9Copying and Pasting Technology Characteristics . . . . . . . . . . . . 3-10

Options Menu for User Preferences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-12

Chapter 4 Technology Characteristics 4-1Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1Frozen vs. Unfrozen Technology Characteristics. . . . . . . . . . . . . . . . . . 4-1Technology Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

Dielectric Layers Positioning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3Conformal Dielectrics Specification . . . . . . . . . . . . . . . . . . . . . . . . . 4-4Conductors Positioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

Restoring Parameters or Canceling . . . . . . . . . . . . . . . . . . . . . . . . 4-7Width and Spacing Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7

Avoiding Generation of Excessive Combinations . . . . . . . . . . . . . . . 4-9Loading an Interconnect Technology Format (ITF) File . . . . . . . . . . . 4-10Setting Nonplanar Technology Characteristics . . . . . . . . . . . . . . . . . . 4-10Specifying the Variation of Dielectric Thicknesses . . . . . . . . . . . . . . . 4-11Specifying the Variation of Conductor Thickness and Width . . . . . . . 4-15Modeling the Dishing Effect. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15Menu Bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18

Chapter 5 User Preferences Notebook 5-1Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1Choosing Database Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1Setting Preferences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

Structures Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

Draft 2/6/06iv RA 2006.03

Raphael Tutorial Table of Contents

Co

nten

ts

Structures Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2Extracting Capacitances for Two-Array Structures . . . . . . . . . . . . 5-3Previewing Structures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3

Simulation Page. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4Simulation Input/Output Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4Additional Command-Line Options . . . . . . . . . . . . . . . . . . . . . . . . 5-5Templates for Generic Structures. . . . . . . . . . . . . . . . . . . . . . . . . . 5-6

Regression Page. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6Location of Default Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7Location of User-Defined Equations . . . . . . . . . . . . . . . . . . . . . . . 5-7Forcing Regression Using Default Models . . . . . . . . . . . . . . . . . . 5-7

Process Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7Applying Preference Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8

Chapter 6 Manually Creating Parasitics Database 6-1Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1Setting up the Structures for Simulation. . . . . . . . . . . . . . . . . . . . . . . . . 6-1

Selecting Generic Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2Generic Structure Types. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3Generic Structures Properties. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4Exporting Generic Structures to Create Actual Structures . . . . . . . . 6-7Selecting Actual Structures and Performing Simulation . . . . . . . . . . . 6-8

Performing Manual Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8Actual Structures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-9

Selecting Actual Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-10Running Simulations and Regression Analysis . . . . . . . . . . . . . . . . . . 6-10Tool Kit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12

Menu Bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12

Chapter 7 Utility Tools For Manual Database Generation 7-1Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1Using Regression Analysis Tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2Key Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

Batch vs. Manual Regression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2Raphael-Defined or User-Defined Equations. . . . . . . . . . . . . . . . . 7-3

Manual Regression Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3Using the Regression Analysis Window . . . . . . . . . . . . . . . . . . . . . . . 7-4

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5Selecting Targets and Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5Extract vs. Fix. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5Running a Manual Regression Analysis. . . . . . . . . . . . . . . . . . . . . 7-6Graphical Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6Tabular Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7

Batch Regression Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-9

Draft 2/6/06RA 2006.03 v


Information Output During Batch Regression . . . . . . . . . . . . . . . . . . 7-9Targets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-10Models and Model Markers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-10Marking a Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-11

User-Defined Equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-11Applying Equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-11One-Array vs. Two-Array . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-12

One-Array Equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-12Two-Array Equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-12Math Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-13Operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-13Parsing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-13Saving to a File. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-13Restoring from a File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-13

Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-13Variables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-13Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14Shared Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14

Menu Bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-15Report Generator for Regression Results . . . . . . . . . . . . . . . . . . . . . . . 7-15

Generating a Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-15A Sample Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-16

Using a Capacitance Curve Tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-20Visualizing Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-20Using the Visualization Window . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-21

Chapter 8 LPE Tools Interface: Dracula 8-1Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1Capacitance Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-2Using Dracula LPE Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3

Step 1: Selecting Target LPE Format . . . . . . . . . . . . . . . . . . . . . . . . 8-3Step 2: Changing Layer Information (optional). . . . . . . . . . . . . . . . . 8-3Step 3: Specifying the Options (optional) . . . . . . . . . . . . . . . . . . . . . 8-4Step 4: Generating the Rule File . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4

Setting LPE Tools Interface Options . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5General Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5

Group 1: Perimeter Coefficient Modeling . . . . . . . . . . . . . . . . . . . 8-5Group 2: Adjacent Layer Specification . . . . . . . . . . . . . . . . . . . . . 8-8Group 3: Lateral Coupling Distance Specification . . . . . . . . . . . . 8-9Group 4: Output Unit Specification . . . . . . . . . . . . . . . . . . . . . . . 8-11

Dracula Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-11Group 1: Non-Interacting Metal Modeling . . . . . . . . . . . . . . . . . 8-11Group 2: Perimeter Coefficient Setting . . . . . . . . . . . . . . . . . . . . 8-14Group 3: Output Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-18

Button Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-18

Draft 2/6/06vi RA 2006.03


Co

nten

ts

Exporting and Importing LPE Interface Options. . . . . . . . . . . . . . . 8-18SRAM Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-19

Chapter 9 LPE Tools Interface: Diva and Vampire 9-1Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1Capacitance Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-2Diva and Vampire LPE Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-3

Step 1: Selecting the Target LPE Format. . . . . . . . . . . . . . . . . . . . . . 9-3Step 2: Changing the Layer Information (optional). . . . . . . . . . . . . . 9-3Step 3: Specifying the Options (optional) . . . . . . . . . . . . . . . . . . . . . 9-4Step 4: Generating the Rule File . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-4

Setting LPE Tools Interface Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-5General Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-5

Group 1: Perimeter Coefficient Modeling . . . . . . . . . . . . . . . . . . . 9-5Group 2: Adjacent Layer Specification . . . . . . . . . . . . . . . . . . . . . 9-8Group 3: Lateral Coupling Distance Specification . . . . . . . . . . . . 9-9Group 4: Output Unit Specification . . . . . . . . . . . . . . . . . . . . . . . 9-10

Diva & Vampire Page. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-11Group 1: Non-Interacting Metal Modeling . . . . . . . . . . . . . . . . . 9-11Group 2: Perimeter Coefficient Setting . . . . . . . . . . . . . . . . . . . . 9-13Group 3: Capacitance Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-16

Button Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-17Exporting and Importing LPE Interface Options. . . . . . . . . . . . . . . 9-17

SRAM Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-17

Chapter 10 LPE Tools Interface: xCalibre and ICextract 10-1Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1Capacitance Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-2

xCalibre and ICextract Terminology . . . . . . . . . . . . . . . . . . . . . . 10-3xCalibre and ICextract LPE Interface. . . . . . . . . . . . . . . . . . . . . . . . . . 10-3

Step 1: Selecting the Target LPE Format. . . . . . . . . . . . . . . . . . . . . 10-4Step 2: Changing the Layer Information (optional). . . . . . . . . . . . . 10-4Step 3: Specifying the Options (optional) . . . . . . . . . . . . . . . . . . . . 10-4Step 4: Generating the Rule File . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5

LPE Tools Interface Option Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5General Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5

Group 1: Perimeter Coefficient Modeling . . . . . . . . . . . . . . . . . . 10-6Group 2: Adjacent Layer Specification . . . . . . . . . . . . . . . . . . . . 10-9Group 3: Lateral Coupling Distance Specification . . . . . . . . . . 10-10Group 4: Output Unit Specification . . . . . . . . . . . . . . . . . . . . . . 10-11

xCalibre & ICextract Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-11Group 1: Non-Interacting Metal Modeling . . . . . . . . . . . . . . . . 10-12Group 2: Regression Equation Selection . . . . . . . . . . . . . . . . . . 10-15Group 3: Output Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-18

Draft 2/6/06RA 2006.03 vii


Button Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-18Exporting and Importing LPE Interface Options. . . . . . . . . . . . . . 10-19

SRAM Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-20

Chapter 11 Field Solvers 11-1Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-1RC2 and RC2-BEM: 2D Resistance and Capacitance Solvers. . . . . . . 11-1

Step 1: Select Input File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-1Step 2: Select Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-1Step 3: Select Solver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-4Step 4: Run Solver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-4

RC3 and RC3-BEM: 3D Resistance and Capacitance Solvers. . . . . . . 11-4Raphael/RC3 Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-5Raphael/QuickCAP Page. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-6

RI3: 3D Resistance and Inductance Solver. . . . . . . . . . . . . . . . . . . . . . 11-6Step 1: Select Input File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-7Step 2: Select Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-7Step 3: Select Solver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-9Step 4: Run Solver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-10Menu Bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-10

Closing the Field Solvers Window. . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-10

Chapter 12 Raphael Interconnect Library 12-1Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-1

Parametrics Library of 30 Structures . . . . . . . . . . . . . . . . . . . . . . . . 12-2Invoking RIL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-3

Appendix A: Capacitance Definitions of Raphael Default Database A-1

Capacitance Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1

Appendix B: Regression Analysis Model Definitions B-1

One Array . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1Mono decreasing: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1Mono increasing: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2Coupling: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2

Two Crossover Arrays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2Mono increasing (bottom array): . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2Mono increasing (top array): . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-3Mono decreasing (bottom array):. . . . . . . . . . . . . . . . . . . . . . . . . . . . B-3

Draft 2/6/06viii RA 2006.03


Co

nten

ts

Mono decreasing (top array): . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-4Crossover: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-4

Two Parallel Arrays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-5Rational (1): . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-5

Different Layers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-5Rational (2): . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-5

Appendix C: Default Regression Models C-1

DRM File Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1Typical DRM File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-2

Default Regression Models. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-5

Appendix D: Mapping Raphael Capacitance to LPE Models D-1

Array Above a Ground Plane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1Array Between Ground Planes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-2Array Crossover Above a Ground Plane . . . . . . . . . . . . . . . . . . . . . . . . D-2Array Crossover Between Ground Planes . . . . . . . . . . . . . . . . . . . . . . . D-3Parallel Arrays Above a Ground Plane. . . . . . . . . . . . . . . . . . . . . . . . . . D-4Parallel Arrays Between Ground Planes. . . . . . . . . . . . . . . . . . . . . . . . . D-4Coincident Edge Above a Ground Plane . . . . . . . . . . . . . . . . . . . . . . . . D-4Coincident Edge Between Ground Planes . . . . . . . . . . . . . . . . . . . . . . . D-4Oversize Structure Between Ground Planes . . . . . . . . . . . . . . . . . . . . . . D-5Different Layers Above a Ground Plane . . . . . . . . . . . . . . . . . . . . . . . . D-5Different Layers Between Ground Planes . . . . . . . . . . . . . . . . . . . . . . . D-5

Appendix E: Field Solver Templates E-1

Technology, Structural and Design Parameters . . . . . . . . . . . . . . . . . . . E-1Technology Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-1Structure Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-2Design Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-4

Simulation Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-8Option Block. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-8Example of User-Defined Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-9

Appendix F: Raphael/Dracula Interface Example F-1

Files Required to Run Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-1Creating the Parasitics Database. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-3

Step 1: Specifying Technology Characteristics . . . . . . . . . . . . . . . . . F-3Step 2: Setting User Preferences . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-6

Draft 2/6/06RA 2006.03 ix


Step 3: Generating the Parasitics Database . . . . . . . . . . . . . . . . . . . . F-6Automatic Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-6Manual Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-6

Generating the LPE File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-6Step 1: Mapping Dracula LPE Layers to Raphael Conductors . . . . . F-6Step 2: Setting the LPE Interface Options . . . . . . . . . . . . . . . . . . . . . F-7Step 3: Generating the Rule Decks with Capacitance Models. . . . . . F-7Step 4: Constructing the Complete Rule File. . . . . . . . . . . . . . . . . . . F-9

Running Dracula LPE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-14Comparing with RC3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-15

Step 1: Generating the Input File for RC3 . . . . . . . . . . . . . . . . . . . . F-15Step 2: Running the RC3 Field Solver. . . . . . . . . . . . . . . . . . . . . . . F-16

Appendix G: Interconnect Technology Format (ITF) File G-1

ITF File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G-1ITF Process File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G-1

Technology Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G-2Process Cross-Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G-2

Conformal Dielectrics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G-3Co-Vertical Conductors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G-3Cladding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G-3Dielectric Air Gaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G-4Layer Etch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G-5Metal Fill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G-6DIELECTRIC Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G-7CONDUCTOR Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G-8VIA Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G-9

ITF Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G-10ITF Attributes Not Supported by Raphael . . . . . . . . . . . . . . . . . . . . . . G-20

Appendix H: TFT Templates H-1

TFT Templates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . H-1TFT1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . H-2TFT2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . H-4TFT3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . H-6TFT4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . H-8TFT5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . H-11

Glossary Glossary-1

Index Index-1

Draft 2/6/06x RA 2006.03

ABOUT THIS GUIDE

About This Manual1

This manual is a tutorial that explains the use of the features provided in the Raphael graphical user interface (GUI). The Raphael GUI helps to systematically perform the large number of simulations necessary to completely characterize the interconnect parasitics for different process technologies. The program transfers the three-dimensional (3D) field solver accuracy to the Layout Parameter Extrac-tor (LPE) tools.

AudienceThis manual is for anyone wanting to use Raphael. By using an example file, the tutorial takes you through all the steps necessary to effectively use the program. The tutorial also briefly discusses other Raphael capabilities, such as the Interconnect Library (RIL). For complete information on those aspects of the program, see the Raphael Reference Manual. Chapter 2 of this tutorial is an overview of the entire flow of Raphael parasitics extraction.

Related PublicationsFor additional information about Raphael, see:

• Synopsys Online Documentation (SOLD), which is included with the software for CD users or is available to download through the Synopsys Electronic Software Transfer (EST) system

• Documentation on the Web, which is available through SolvNet at http://solvnet.synopsys.com

• The Synopsys MediaDocs Shop, from which you can order printed copies of Synopsys documents, at http://mediadocs.synopsys.com

• You might also want to refer to the documentation for the following related Synopsys products:- For information on Raphael installation procedures, see the TCAD

Products and Utilities Installation Manual.

RA 2006.03 xiii

Draft 2/6/06

- For information on the use of STUDIO Visualize tool, see the STUDIO Visualize User Manual.

- For information on the Taurus-Layout tools, see the Taurus Layout User Manual.

ConventionsThe following conventions are used in Synopsys documentation.

Customer SupportCustomer support is available through SolvNet online customer support and through contacting the Synopsys Technical Support Center.

Accessing SolvNetSolvNet includes an electronic knowledge base of technical articles and answers to frequently asked questions about Synopsys tools. SolvNet also gives you access

Convention Description

Courier Indicates command syntax.

Italic Indicates a user-defined value, such as object_name.

Bold Indicates user input—text you type verbatim—in syntax and examples.

[ ] Denotes optional parameters, such as write_file [-f filename]

... Indicates that a parameter can be repeated as many times as nec-essary:pin1 [pin2 ... pinN]

| Indicates a choice among alternatives, such aslow | medium | high

\ Indicates a continuation of a command line.

/ Indicates levels of directory structure.

Edit > Copy Indicates a path to a menu command, such as opening the Edit menu and choosing Copy.

Control-c Indicates a keyboard combination, such as holding down the Control key and pressing c.

xiv RA 2006.03

Draft 2/6/06

to a wide range of Synopsys online services including software downloads, Documentation on the Web, and entering a call to the Support Center.

To access SolvNet:

1. Go to the SolvNet Web page at http://solvnet.synopsys.com.

2. If prompted, enter your user name and password. (If you do not have a Synop-sys user name and password, follow the instructions to register with SolvNet.)

If you need help using SolvNet, click SolvNet Help in the Support Resources section.

Contacting the Synopsys Technical Support CenterIf you have problems, questions, or suggestions, you can contact the Synopsys Technical Support Center in the following ways:

• Open a call to your local support center from the Web by going to http://solvnet.synopsys.com (Synopsys user name and password required), then clicking “Enter a Call to the Support Center.”

• Send an e-mail message to your local support center.- E-mail [email protected] from within North America. - Find other local support center e-mail addresses at

http://www.synopsys.com/support/support_ctr.• Telephone your local support center.

- Call (800) 245-8005 from within the continental United States.- Call (650) 584-4200 from Canada.- Find other local support center telephone numbers at

http://www.synopsys.com/support/support_ctr.

RA 2006.03 xv

Draft 2/6/06

http://solvnet.synopsys.com

http://solvnet.synopsys.com

http://www.synopsys.com/support/support_ctr

http://www.synopsys.com/support/support_ctr

xvi RA 2006.03

Draft 2/6/06

CHAPTER 1

R

1. Parasitics

Extractio

n

Getting Started1

Raphael performs on-chip interconnect parasitics extraction by generating com-prehensive interconnect parasitics databases for technologies used to prepare rule decks for Layout Parameter Extractor (LPE) tools. Currently, such LPE tools as Cadence Dracula, Diva and Vampire, and Mentor Graphics xCalibre and ICextract, can use Raphael generated rule decks.

Raphael DirectoryIn this tutorial, RA_PATH is used to indicate the directory where Raphael is installed.

Raphael Parasitics Database CreationIn the past, characterizing a technology and then creating a database to summarize the results was laborious and time-consuming.

Raphael systematically generates the large number of field solver simulations nec-essary to accurately and completely characterize the interconnect parasitics for different process technologies. Because the Raphael graphical user interface man-ages large databases, the total characterization cycle is reduced.

Since Raphael transparently handles the large amounts of data generated during parasitics analysis automatically, it is useful to interconnect technologists in foundry companies. Raphael allows technology developers to focus on intercon-nect characterization rather than on file management.

Example

Ten actual structures were simulated to characterize a single-poly, two-metal pro-cess for two generic structures (array above ground plane and array between ground planes). For each structure, several simulation files were set up and run for various width and spacing combinations. In one example, 810 simulation files

A 2006.03 1-1

Draft 2/6/06

LPE Tools Interface Raphael Tutorial

were generated and run automatically. The total characterization cycle was reduced from 10 to 15 days to only a few hours using Raphael.

LPE Tools InterfaceOnce a comprehensive interconnect parasitics database is generated, you can load the database into the LPE Tools Interface to generate rule decks with accurate par-asitic capacitance coefficients and equations. Currently, the interface supports Cadence Dracula, Diva and Vampire, and Mentor Graphics xCalibre and ICextract.

Starting RaphaelTo start Raphael and open the Raphael main window from the UNIX environment, type the command:

raphael

Figure I-1 Raphael main window

1-2 RA 2006.03

Draft 2/6/06

Raphael Tutorial Understanding the Raphael Main Window

1. Parasitics

Extractio

n

Understanding the Raphael Main WindowThe four modules on the window (Figure 1) correspond to the following four main functions:

1. To create an interconnect parasitics database or to access the LayoutParameter Extractor (LPE) tools interface, use the Parasitics Database & LPE Tools Interface module.

2. To select from the Field Solvers module to access the two-dimensional (RC2) and three-dimensional (RC3 and RI3) field solvers embedded in the Raphael main window.

3. To access the parametric interconnect library, open the Raphael Interconnect Library (RIL) module.

4. To import a GDS II file and/or access Raphael-NES; select the Taurus Lay-out & Net Extraction System module.

If you purchased the full Raphael license, all modules are active, except the LPE Tools Interface, which requires an additional license. Contact Synopsys TCAD Business Unit for details.

Parasitics Database and LPE Tools Interface Module

The first module in the Raphael main window is the Parasitics Database & LPE Tools Interface. This module enables you to:

• Characterize the interconnect parasitics for a given technology.

• Create, inspect, or modify an existing database for a given technology.

• Perform regression analysis (curve fitting) to fit models to the results.

• Generate a report file which contains the summary of capacitance tables or regression analysis.

• Generate rule decks with accurate interconnect parasitic capacitance coeffi-cients for a number of LPE tool.

• Transfer Synopsys TCAD-driven accuracy to the full-chip layout parameter extraction, based on the Poisson solvers of Raphael.

To invoke this module, click the associated icon. Creating and using the parasitics database is described in detail in Chapter 3. The Raphael interface to LPE tools is described in Chapters 8 through 8.

RA 2006.03 1-3

Draft 2/6/06

GUI Conventions Raphael Tutorial

Field Solvers Module

The second module in the Raphael main window, Field Solvers, provides access to the program’s two- and three-dimensional Poisson field solvers.

• Click the RC2… button to select the RC2 submodule. Use it to extract resis-tance, capacitance, and inductance in a two-dimensional electrical case.

• Click the RC3… button to select the RC3 field solver. It is a three-dimensional electrothermal resistance-capacitance interconnect analyzer.

• Click the RI3… button to select the RI3 field solver. Use the RI3 submodule to extract resistance and inductance for a three-dimensional case.

To access the selected module, click the icon associated with Field Solvers. Chapter 11 of this tutorial provides more details on the use of the Field Solvers module. A complete description of the above field solvers can be found in the Raphael Reference Manual.

Interconnect Library

The Interconnect Library module provides a parameterized library of 30 struc-tures.

• Use this module to characterize the different interconnect elements present in a design.

• Access the non-GUI features of Raphael.

• Click the RIL… button to open a UNIX shell with access to the different ele-ments available in the library.

This mode of operation is briefly discussed in Chapter 12 of this tutorial and is described at length in the Raphael Reference Manual.

Taurus Layout and Net Extraction System

Refer to the Taurus-Layout Tutorial and the Raphael-NES User Guide for further information.

GUI Conventions The following sections describe conventions used in the Raphael program GUI.

Mouse Button

Most workstation computers have a mouse with three buttons. The functions of the three buttons depend on the “look” (Open Look or Motif) that has been selected. Throughout this manual, the mouse buttons are referred to by name

1-4 RA 2006.03

Draft 2/6/06

Raphael Tutorial GUI Conventions

1. Parasitics

Extractio

n

(SELECT or MENU), rather than by position (left, right, or middle). Table 1 shows the mouse button definitions for the two most common looks, Open Look and Motif.

Window Buttons

Many of Raphael’s windows have one or more buttons, which you click by using the SELECT mouse button. The functions of these buttons are as follows:

A button is not currently active if the label displays light, faint lettering. Attempts to click the button are ignored.

Menus

Throughout this manual, the shorthand convention “execute Menu➔Item” means to use the MENU mouse button to select Item from Menu.

To do this, move the cursor to the desired Menu, then press and hold the MENU mouse button to display the items available under the menu. While continuing to

Table 1 Mouse Button Definitions

Name Open Look Motif Use

SELECT Left Left Select objects

MENU Right Left Display and choose menus

MULTIPLE SELECTION

Ctrl-Left Ctrl-Left Select disjointed objects

Button Function

OK The entries or changes you made in the window are accepted and the window is closed. For windows that perform an action (such as a Load window), the action is also performed.

Apply The entries or changes you made in the window are accepted, but the window is not closed. This allows you to continue mak-ing changes in this window. For windows that perform an action (such as a Load window), the action is performed and the button may be labeled with the appropriate action verb such as Load rather than Apply.

Reset The entries or changes you made in the window since the most recent Apply are ignored, and the window is reset to the state it was in at the most recent Apply.

Cancel The entries or changes you made in the window since the most recent Apply are ignored, the window is reset to the state it was in at the most recent Apply, and the window is closed.

Close The window is closed.

RA 2006.03 1-5

Draft 2/6/06

GUI Conventions Raphael Tutorial

hold the MENU mouse button, drag the mouse down until the desired Item is highlighted, then release the mouse button.

If a menu item appears in light, faint lettering, the item is not currently available. Attempts to select the item will be ignored.

Keyboard Accelerators

If you prefer to use the keyboard instead of the mouse for menu selection, there are keyboard shortcuts (accelerator keys) for many of the menu selection opera-tions.

For example, in Figure 2 above, the first letter of each of the menu bar items is underlined (File, Edit, and View). You can display a menu by pressing and hold-ing the ALT key, followed by the desired letter. For example, ALT-F will display the File menu. Once a menu is displayed, notice that one letter in each item is under-lined. Make your selection by pressing the corresponding letter on your keyboard.

Once a menu is displayed, you may move up and down the menu using the up-arrow ↑ and down-arrow ↓ keys. You may move left and right (from menu to menu) using the left-arrow ← and right-arrow → keys. Press RETURN to make your menu selection.

Figure I-2 Select File➔Save menu item

1-6 RA 2006.03

Draft 2/6/06

CHAPTER 2

R

1. Parasitics

Extractio

n

Interconnect Parasitics Extraction: Entire Flow 2

This chapter provides an overview of the Raphael parasitics extraction process, with a typical user scenario that illustrates the process of parasitics extraction.

Raphael Flow to Extract Interconnect Parasitics The following sequence defines the Raphael workflow, from generating a parasit-ics database to obtaining the final SPICE models of the interconnects that need to be extracted. Refer to Figure 2-1 for a graphical representation of the flow.

Building a Parasitics Database

• Technology characteristics are input to Raphael .

• Field solver simulations are performed on predefined structures to build an interconnect parasitics database.

• The summary file containing capacitance tables is generated.

• The LPE Tools Interface generates a rule deck containing capacitance models.

Detailed steps to build a parasitics database are outlined in Chapter 3.

A 2006.03 2-1

Draft 2/6/06

Raphael Flow to Extract Interconnect Parasitics Raphael Tutorial

Generating a LPE Rule Deck with Capacitance Models

• If layer names, spacing and width parameters (LPE Layer Information) differ from the specified technology characteristics, they are input to the LPE tools interface.

• The result is a rule file with accurate parasitic capacitance coefficients in LPE tool syntax.

• The rule deck is input to the LPE tool, along with information from the layout database, such as the GDS II stream.

• The final SPICE models of the interconnects that need to be extracted are completed.

Figure 2-1 Raphael Parasitics Extraction flow

Parasitics Database

Field Solver

LPE Layer Information

LPE Rule Deck

LPE Tools

Technology Characteristics

LPE Tool Interface

Layout Database (GDS II)

SPICE Models

Raphael

Summary File

(Dracula, Diva, Vampire,xCalibre, ICextract)

(Capacitance Tables)

Raphael Flow

LPE Flow

2-2 RA 2006.03

Draft 2/6/06

Raphael Tutorial Raphael Flow to Extract Interconnect Parasitics

R

1. Parasitics

Extractio

n

LPE interfaces are covered in Chapter 8 for Dracula, Chapter 9 for Diva and Vampire, and Chapter 10 for xCalibre and ICextract.

Figure 2-2 shows how a foundry process engineer uses Raphael to characterize the interconnect parasitics and to create parasitics databases for various technologies.

After an interconnect parasitics database is created by the technology developer, the foundry can then transfer either the summary file containing capacitance tables or the rule decks to their customers for interconnect models.

Using Raphael, end users can generate interconnect models once they obtain the technology information from foundries.

Figure 2-2 Raphael user model

design houses

companies

designers

Capacitance Tables

Foundry 1

Foundry n

End Users:

- In-house

- FablessRaphael

- External

orRule Decks

A 2006.03 2-3

Draft 2/6/06

Raphael Flow to Extract Interconnect Parasitics Raphael Tutorial
2-4 RA 2006.03
Draft 2/6/06

CHAPTER 3

R

5. Man

ual

Mo

de

Creating a Parasitics Database3

OverviewIn this chapter you begin working with Raphael to create new and/or inspect exist-ing parasitics databases.

To create and/or inspect a parasitics database, begin in the Parasitics Database & LPE Tools Interface module of the Raphael main window (Figure I-1).

Click the icon associated with this module to open the Raphael Parasitics Database window (Figure 3-1).

This window opens only if you are an authorized licensed user of this module. Otherwise, an unauthorized user error message is displayed in the UNIX shell from which you started Raphael.

Raphael Parasitics Database WindowThe Raphael Parasitics Database window is a self-guided, four-part interface that summarizes the main steps used to create a parasitics database.

• Define a new database name or select from existing databases.

• Define the Technology Characteristics.

• Create a parasitics database in the Simulation and Regression panel, using either the fully automatic method or the manual method.

The two methods are explained in “Simulation and Regression,” p. 3-5.

• Generate the summary file containing capacitance tables of the parasitics database.

• Invoke the desired LPE Tools Interface to generate rule decks for LPE tools.

A 2006.03 3-1

Draft 2/6/06

Raphael Parasitics Database Window Raphael Tutorial

Sample Databases

In the 1. Database Names panel of the window, you see an existing database named sram under the Select a database: section.

This database is provided as an example. It is installed on your system when Raphael is installed. To select the sample database, click the database name.

If the sram database is not present in the Select a database: portion of the win-dow, ask the installer of Raphael on your system (the UNIX systems administrator or CAD manager) where to find the directory containing the database.

Figure 3-1 Raphael Parasitics Database window

3-2 RA 2006.03

Draft 2/6/06

Raphael Tutorial Raphael Parasitics Database Window

5. Man

ual

Mo

de

Defining Pathnames in the Database Directory

The panel 1. Database Names of the Raphael Parasitic Database window con-tains a text field labeled Directory:. This field shows the full UNIX path of the directory that contains working parasitics databases. This text field may be edited. While it is convenient to use technologies as the directory name, you may use any name you wish.

There are four ways to set the UNIX pathname of the desired directory:

1. Change the text directly by clicking in the Directory: field and edit the con-tents so that it contains the full UNIX path of the desired directory.

a. After you enter the search pathname, press the RETURN or ENTER key to set the new path. The list of Database Names updates to show the data-bases contained in the directory you entered.

With this method, you automatically lose the pathname every time you exit the Raphael environment, The next time you run Raphael, you must re-enter the pathname of the directory.

2. Click on Select... button below the Directory: field to open a directory browser. Select the location of your directory containing the parasitics data-bases and press the RETURN or ENTER key to set the new path.

3. Before starting Raphael, set the RA_RPD_USERDIR environment variable. The environment variable is an optional variable that specifies the directory containing the databases.

When you start Raphael and open the Raphael Parasitics Database window, the program checks the environment variable to ensure that it is set to an exist-ing directory. If it is set, Raphael uses this environment as the default for the Directory: text field and automatically displays the list of parasitics databases in the directory.

a. To set the environment variable in a C-shell, type the following command:

b. To set the environment variable in a Bourne or Korn shell, type the fol-lowing at a UNIX command line:

RA_RPD_USERDIR=<full UNIX path of directory>

You must set this variable before you start Raphael. Setting it after Raphael is running does not change the Directory: text field.

The environment variable is only set for the shell in which you typed the setenv (or equivalent) command, and is lost when you exit the shell.

4. Set the RA_RPD_USERDIR environment variable for all new shells, by modi-fying your .cshrc, .login, .login.env, or .profile file with the following line:

See your UNIX systems administrator for guidance on which file to modify.

setenv RA_RPD_USERDIR <full UNIX path of directory>

setenv RA_RPD_USERDIR <full UNIX path of directory>

RA 2006.03 3-3

Draft 2/6/06

Raphael Parasitics Database Window Raphael Tutorial

Note:If you set the RA_RPD_USERDIR environment variable to a directory that does not exist, and then start Raphael, the following error message appears in the UNIX window in which you started Raphael:

***NOTE: The RA_RPD_USERDIR environment variable is not properly set. This variable is optional. It should specify an existing directory containing the “Databook” technol-ogy subdirectories.

Note:The directory you enter in the Directory: text field must start with a slash (/) and must be an existing directory on your system; otherwise when you press RETURN, the list of database names displays (invalid direc-tory). If you enter a valid existing directory, but there are no databases in the directory, the list of database names displays (no technolo-gies found).

If you have difficulty setting the Database Names Directory: see your UNIX systems administrator or the person who installed Raphael on your system.

Selecting a New Database Name

To define a new Database Name:

1. Set the Database Names Directory: to the appropriate path (See “Defining Pathnames in the Database Directory,” p. 3-3).

2. Press RETURN or ENTER to enter the new path.

3. Click in the New database name: field.

4. Type the name of the new database.

5. Press RETURN or ENTER to enter the new name.

The new Database Name is added to the list of names and is automatically selected.

Note:You may implicitly copy technology characteristics of one database to a new one by following the procedure described in “Automatic Copying/Pasting,” p. 3-11.

After generation of the new database, you can define its technology characteristics as described in the following section.

3-4 RA 2006.03

Draft 2/6/06

Raphael Tutorial Simulation and Regression

5. Man

ual

Mo

de

Defining Technology Characteristics

The panel labeled 2. Technology Characteristics of the Raphael Parasitics Database window contains a single button labeled Define…. Click this button to open a new window summarizing the technology-related aspects of the selected database (See Figure 4-1, p. 4-2).

Chapter 4 describes in detail how to define Technology Characteristics.

Simulation and RegressionThe panel of the Raphael Parasitics Database window labeled 3. Simulation and Regression contains two sections:

1. Fully automatic database creation

2. Manual database creation

Fully Automatic Method

The fully automatic method is well-suited for those users who are primarily inter-ested in Raphael’s interface to LPE tools or output capacitance table.

Note:Choose the structures desired and the simulation preferences for auto-matic database generation in the Raphael Parasitics Database window menu bar by executing the Options➔User Preferences menu item. Refer to Chapter 5 for further details on setting preferences.

To use the fully automatic method, click the Automatically Create button (see Figure 3-2).

Raphael automatically selects the appropriate structures and runs the field solver simulations.

By using the automatic method, you omit the steps contained in Chapter 6, “Man-ually Creating Parasitics Database” since Raphael performs those operations for you.

Figure 3-2 Raphael Parasitics Database window panel for Automatically Create method

RA 2006.03 3-5

Draft 2/6/06

Simulation and Regression Raphael Tutorial

PreviewingStructures

Click the Automatically Create button to open a window (Figure 3-3) that pre-views structures before proceeding with the simulation.

Click Preview to view a second window that displays the selected structures along with a popup window indicating that you are in Preview mode. To proceed with parasitics database generation, after you click the Automatically Create button, click the Create button.

When you click the Create button, a popup window (Figure 3-4) warns you that this simulation operation may be time consuming. (This is especially true if the All structures option is chosen.) If you wish to automatically exit Raphael after the simulations are performed click on the Automatically exit after simulation toggle. Click Cancel to abort database creation.

Note:After you click the OK button in the popup window, it may take some time (several hours or even longer) for Raphael to complete the database creation. During this time, other operations are not available.

Figure 3-3 Preview structures for Automatically Create popup window

Figure 3-4 Automatically Create popup window

3-6 RA 2006.03

Draft 2/6/06

Raphael Tutorial Generating Capacitance Tables

5. Man

ual

Mo

de

Manual Method

The manual method gives you greater control over the database creation process: visualizing capacitance curves, performing regression analysis, and generating a report containing regression results. The majority of users, however, only need to use the Fully Automatic Method.

There are two steps to manually create a parasitics database:

1. Select the generic and actual structures desired for analysis.

2. Manually create the database itself.Several utility tools are available in this step, such as a regression analysis tool, a regression report generator, and a plotter for the capacitance curve.

Creating and inspecting a parasitics database using the manual mode is discussed in Chapter 6. The utility tools available in this mode are discussed in Chapter 7.

Generating Capacitance TablesFollowing the simulation of all selected structures, a summary of the simulation results can be generated using the Capacitance Tables… button in Panel 4 of the Raphael Parasitics Database window. Sample output is partially shown in Figure 3-6.

Invoking LPE Tools InterfaceThe LPE Tools Interface window can be invoked in Panel 4 of the Raphael Parasitics Database window. Chapter 8 (Cadence Dracula), Chapter 9 (Cadence Diva and Vampire), and Chapter 10 (Mentor Graphics xCalibre and ICextract) describe the LPE Tools Interface module in full detail.

Figure 3-5 Raphael Parasitics Database window panel for manually creating a database

RA 2006.03 3-7

Draft 2/6/06

Invoking LPE Tools Interface Raphael Tutorial

Version: 0001Creation Date: Tue Jul 14, 1998 3:54:42 PM PDT-----------------------------------------------------------------

DATABASE: /usr14/tma/raphael/dev/rpd/technologies

TECHNOLOGY CHARACTERISTICS --------------------------

This technology contains 7 layers:

MET2 (conductor) MET1 (conductor) POLY (conductor) diel_3 (dielectric) diel_2 (dielectric) . . CAPACITANCE SUMMARY ------------------- DEFINITIONS OF VARIOUS CAPACITANCES:

Ctotal {fF/um} Total capacitance of a conductor to all others.

Cbottom {fF/um}: Capacitance between a conductor to the bottom ground plane.

Ctop [fF/im}: Capacitance between a conductor to the top ground plane.

Ccoupli [fF/um]: Coupling capacitance between two conductors in the same layer.

Ctbcc [fF/um]: Coupling capacitance between two conductors at two different layers. . . CAPACITANCE TABLE LIST -----------------------

Generic Structure Name: arr_above_gpActual Structure Name: POLY,above,substrate

C area: 6.90627e-02

Width Spacing Ctotal Cbottom Ccoupli Cperimeter Lateral ----------- ----------- ----------- ----------- ----------- ----------- ----------- 8.00000e-01 6.00000e-01 1.95936e-01 1.01535e-01 4.72007e-02 2.31422e-02 2.83204e-02 8.00000e-01 8.00000e-01 1.83386e-01 1.10408e-01 3.64889e-02 2.75791e-02 2.91911e-02 8.00000e-01 1.00000e+00 1.77358e-01 1.18024e-01 2.96669e-02 3.13868e-02 2.96669e-02

Figure 3-6 The partial listing of the summary for capacitance tables of sram technology

3-8 RA 2006.03

Draft 2/6/06

Raphael Tutorial Menu Bar

5. Man

ual

Mo

de

Menu BarThe menu bar of the Raphael Parasitics Database window contains the menus File, Edit, and Options.

FileThe File menu contains only one menu item, Close, which closes the window.

Edit

The Edit menu enables you to edit the parasitics database by Deleting or Copying and Pasting the technology characteristics from one database to another.

Deleting aDatabase

To completely remove the database you have selected, click in the Select a database: part of the 1. Database Names window panel to select the database name, then execute Edit➔Delete selected database.

CAUTIONThe Edit➔Delete selected database operation is not reversible. This oper-ation results in the permanent removal of ALL information for the selected database, including:

• All database characteristics (layer names, properties, widths, and spacings)

• All field solver simulation results for all structures in the database

• All regression analysis results for all structures in the database

To keep the database, click the Cancel button in the popup window.

Note:After you click the OK button in the popup window, it may take some time for Raphael to complete the deletion. Other operations are not available during the deletion.

Figure 3-7 Edit➔Delete popup window

RA 2006.03 3-9

Draft 2/6/06

Menu Bar Raphael Tutorial

Copying andPasting

TechnologyCharacteristics

You may use the Raphael Parasitics Database window menu bar to copy and paste technology characteristics. You may do this manually, using the Edit➔Copy technology characteristics and Edit➔Paste technology characteristics menu items. For additional details, see “Manually Copying/Pasting,” p. 3-11. You may copy and paste automatically when creating a new database. See "Automatic Copying/Pasting," p.3-11 .

Note:You may copy and paste only the technology characteristics, not a com-plete parasitics database (with its associated simulation and regression information).

Technology characteristics include conductor and dielectric names, thicknesses, widths and spacings. These items, which you enter, appear in the Technology Characteristics window (Figure 4-1, p. 4-2).

Note:You can copy from any database, but you can only paste to an unfrozen database. (An unfrozen database does not yet have a parasitics database or any actual structures set up.) The technology characteristics of a fro-zen database cannot be modified. See “Frozen vs. Unfrozen Technology Characteristics,” p. 4-1.

• When you click the name of a new, undefined database in the Raphael Parasitics Database window, the status line at the bottom of the window dis-plays the following information:

This Technology is not frozen (You may modify this technology).

You may paste to this database and modify the technology characteristics.

• When you click the name of an existing, defined database, the status line dis-plays:

This technology is frozen (It cannot be modified).

You cannot paste to such a database or modify its technology characteristics.

If you attempt to paste to a database that has already been frozen, a popup window informs you that you cannot paste to the selected database.

Figure 3-8 Result of attempt to paste already-defined database popup window

3-10 RA 2006.03

Draft 2/6/06


5. Man

ual

Mo

de

AutomaticCopying/Pasting

To copy and paste technology characteristics automatically when you create a new database, use the following steps:

1. Select an existing database name to choose the technology characteristics you wish to copy.

2. Create a new technology by moving to the New database name: field in the Raphael Parasitics Database window.

a. Type the new name.

b. Press RETURN or ENTER.

The new name is added to the list of names and is automatically selected.

The section “Selecting a New Database Name,” p. 3-4 discusses the details.

3. The status line at the bottom of the Raphael Parasitics Database window informs you that the new database’s technology characteristics were initial-ized by defaulting to the technology characteristics of the database chosen in Step 1.

For example, to make a copy of the sram database:

• Click the name sram.

• Type a new name (e.g., sram_copy).

• Click RETURN or ENTER.

The status line displays:

Initialized “sram_copy” by copying and pasting “sram”.

Manually Copying/Pasting

To manually copy and paste technology characteristics:

1. Select an existing database name to choose the technology characteristics you wish to copy.

2. Execute Edit➔Copy technology characteristics.

3. Select the name of the database whose technology characteristics you wish to modify.

4. Execute Edit➔Paste technology characteristics. (The Paste menu item is disabled until you use the Copy menu item).

Note:You can copy from any database, but you can only paste to an unfrozen database. (An unfrozen database does not yet have a parasitics database or any actual structures set up.) The technology characteristics for a fro-zen database cannot be modified. (See “Frozen vs. Unfrozen Technology Characteristics,” p. 4-1.) The conductor and dielectric names, thick-nesses, widths, and spacings for the pasted technology are auto-updated in the Technology Characteristics window.

Use the Technology Characteristics window to modify the technology charac-teristics for the pasted technology.

RA 2006.03 3-11

Draft 2/6/06

Menu Bar Raphael Tutorial

Note:When you have finished editing the technology parameters in the Technology Characteristics window, be sure to click the OK or Apply button or File➔Save to enter your changes; otherwise, they will be lost if you change to a different technology.

Options Menu for User Preferences

The Options menu enables you to set preferences with the UserPreferences… menu item. The preferences, which appear on four distinct pages, can be set in four different areas:

• Structures Page: By default, only 2D structures are simulated during the automatic generation of a parasitics database. Additionally, you can select 3D structures using this page.

• Simulation Page: Select required preferences for the simulation process of the structures you selected.

• Regression Page: Following simulation, select regression analysis prefer-ences.

• Process Page: Select the working capacitance database. Three capacitance databases are available for each technology directory: stdCap, minCap, and maxCap.

Further details on the User Preferences notebook are discussed in Chapter 5.

3-12 RA 2006.03

Draft 2/6/06

CHAPTER 4

R

Technology Characteristics4

OverviewThis chapter teaches you how to define technology characteristics for parasitics databases. Technology characteristics are data, such as conductor and dielectric names, thicknesses, widths and spacings, entered by the user that appear in the Technology Characteristics window.

To open the Technology Characteristics window (Figure 4-1, p. 4-2), click the Define… button in the Raphael Parasitics Database window (Figure 3-1, p. 3-2).

The Technology Characteristics window summarizes all technology-related aspects of the selected database. To display information about a database, click the desired database name in the Raphael Parasitics Database window.

Frozen vs. Unfrozen Technology CharacteristicsYou may edit technology parameters directly, cell by cell. You may also copy all the technology and design parameters from one database to another database (see Chapter 3).

A 2006.03 4-1

Draft 2/6/06

Frozen vs. Unfrozen Technology Characteristics Raphael Tutorial

]

Note:You may copy and paste only technology characteristics, not a complete database (with its associated simulation and regression information).

You can copy the technology characteristics from any database, but you can only paste to an unfrozen database (one which does not yet have the actual structures set up for simulation).

If the actual structures have been set up for simulation, you cannot modify the technology characteristics for a database. If you use the fully automatic simulation mode, when you click the Automatically Create button in the Raphael Parasitics Database window, the database is “frozen” (Figure 3-1, p. 3-2). In the manual simulation mode, the database is frozen when you click the Setup button in the Select Structures window. See Chapter 6, Figure 6-1, p. 6-3, to see the window that manually sets up the actual structures for simulation.

• When you click the name of an unfrozen database in the Raphael Parasitics Database window, the status line at the bottom of the window dis-plays the following information:

This technology is not frozen (You may modify this technology).

You may paste to this database and modify the technology characteristics.

Figure 4-1 Technology Characteristics window, showing information for the sram database

4-2 RA 2006.03

Draft 2/6/06

Raphael Tutorial Technology Parameters

• When you click the name of an existing, defined database, the status line dis-plays:

This technology is frozen (It cannot be modified)

You cannot paste to such a database or modify its technology characteristics.

Note:If the database is frozen, the information displayed in the Technology Characteristics window appears in red. Red text cannot be modified.

Technology ParametersThe Technology Parameters panel of the Technology Characteristics window displays information for conducting and dielectric layers. The thickness, Z min, and Z max values are all in microns. For both conductors and dielectrics, Z min is the vertical coordinate of the bottom of the layer. Z max is the vertical coordinate of the top of the layer.

• To change a technology parameter, click the desired cell and edit the value.

• To enter your change, click another cell, press RETURN or ENTER, or move the mouse to another part of the window.

Note:You cannot edit a cell where the text appears in red. Specifically, you cannot edit any Z max conductor values, nor any Z min or Z max dielectric values.

You may create new conductors and dielectrics, as well as perform cut, copy, and paste operations on a row-by-row basis. See Menu Bar, p. 4-17 for additional details.

Dielectric Layers Positioning

Dielectric layers are always stacked, one on top of another. The bottom of the bot-tom-most dielectric has a Z min value of zero, by definition. Thus, in Figure 4-1, p. 4-2, the Z min value of diel_0 is 0. The Z max value of a dielectric is the sum of the Z min value of that dielectric and its layer thickness (shown in the dielectric Total Thickness column).

For diel_0, Z max = Z min + total thickness = 0 + 0.5 = 0.5. Since the dielec-trics are stacked on top of each other, Z min for diel_1 = Z max for the dielec-tric below it (diel_0) = 0.5. Z max for diel_1 = Z min + total thickness = 0.5 + 1.4 = 1.9. You can verify these values in Figure 4-1, p. 4-2.

RA 2006.03 4-3

Draft 2/6/06

Technology Parameters Raphael Tutorial

Conformal Dielectrics Specification

Conformal dielectrics can be now specified in the Technology Characteristics window (see Figure 4-1, p. 4-2).

You will have to specify the dielectric, just as any other dielectric, and then describe the conductor to which the dielectric is conformal to in the Conf.Cond column.

The thickness of the conformal dielectric on top of the conductor is specified in the Conf.Thick column. Only the step height needs to be specified in this column.

The sidewall thickness can also be specified in the Conf.SWThick column, but this is just for housekeeping purposes.

Figure 4-2 Conformal dielectric specification, example 1


Metal

Conf.Thick

Diel.Thick

Metal

Conf.Thick

Diel.ThickDielectric

4-4 RA 2006.03

Draft 2/6/06

Raphael Tutorial Technology Parameters

Coated Dielectrics can be specified as a variation of the conformal dielectrics by setting the Diel.Thick = 0 and Conf.SWThick = 0.0 and specifying the Conf.Thick to the coating thickness.

The conformal dielectric thickness is used in the calculation of the area capaci-tance of the structures.

Note:

• If you use the default Raphael field solver templates (by selecting the Standard Raphael templates in the Simulation Page of the User Pref-erences window), the conformal dielectric statements will be written to the field solver input files.

• However, you must implement Raphael input templates to include these conformal dielectrics if you use your own field solver templates (by se-lecting and specifying the User defined directory in the Simulation Page of the User Preferences window). The conformal dielectric thick-nesses and dielectric constants are written to the input file for this pur-pose.

The section of the input file in which these values are written is given below.


MetalConf.Thick

Diel.Thick,Conf.SWThick=0.0

$ Technology parameters param hC6=0.032; swhC6=0; EC6=5.9; hC7=0.01; swhC7=1.5; EC7=3.9; hC10=0.032; swhC10=0; EC10=5.9; hC11=0.01; swhC11=1.5; EC11=3.9;

$ Design parameters param arraywidth = 1e-06 ; arrayspace = 2e-07 ; E_top_cond_bot=E7; E_top_cond_top=E8; E_top_cond_conf_1=EC6; E_top_cond_conf_2=EC7;

RA 2006.03 4-5

Draft 2/6/06

Technology Parameters Raphael Tutorial

CAUTIONThe conformal thickness (Conf.Thick) and sidewall thickness (Conf.SW Thick) should be specified carefully as incorrect specification of these pa-rameters can cause the program to fail.

Conductors Positioning

In contrast, the conductors are arbitrarily positioned in the dielectric stack, based on the user-specified conductor Z min value.

For example, in the sram technology in Figure 4-1, p. 4-2, the bottom of the POLY layer (Z min) is at 0.5 microns, which is the same as the top (Z max) of the diel_0 layer. Z max for the POLY layer is 0.9, which is below the top (Z max) of the diel_1 layer at 1.9 microns. Thus, POLY rests on top of diel_0 and is enclosed by diel_1. See Figure 4-5, p. 4-6.

With Raphael you can define different kinds of structures using appropriate tech-nology characteristics and field solver template files. Refer to Appendix E: Field Solver Templates for further information. For example, Figure 4-6, p. 4-7 displays a typical trapezoidal structure with conformal dielectrics that can be defined in Raphael. The conductors and dielectrics technology, and width and spacing parameters, are specified in the Technology Characteristics window. The struc-tural details are specified in the field solver templates to generate user-defined structures.

The trapezoid database shipped along with the sram database for this tutorial is an example of such a user-defined structure.

Figure 4-5 Interpretation of conductor and dielectric thicknesses for the sram database (Step 2a of Figure 4-1)

MET1MET1

diel_1

diel_2

0.4

0.8

diel_0

substrate

Z = 4.2

POLY POLY

1.9

0.5

0

}

}

4-6 RA 2006.03

Draft 2/6/06

Raphael Tutorial Width and Spacing Parameters

Note:It is important to understand the conventions used for the conductor and dielectric thicknesses. The dielectric thickness is the total dielectric layer thickness. This is a change in convention from previous versions (Raphael 3.1 and earlier). Raphael automatically converts from the old convention to the new when you access previously-created databases.

RestoringParameters or

Canceling

Click the Reset button to restore the parameters to the last setting established by OK or Apply. Click Cancel to cancel any changes since the last OK or Apply. OK and Cancel automatically close (dismiss) the window.

CAUTIONIf you load an Interconnect Technology File (ITF) file into the Technology Characteristics window as described later in this chapter, restoring the pa-rameters to the last setting is not possible.

Width and Spacing ParametersThe Width and Spacing Parameters panel of the Technology Characteristics window displays the width and spacing values (in microns) to be used when simulations are performed.

• Width refers to the width of a conducting trace.

• Spacing refers to the space between adjacent conducting traces in an array of traces.

The columns labeled Min 1, Max 1, and Step 1 specify the minimum, maximum, and step size to use when varying the width or space. The columns labeled Min 2, Max 2, and Step 2 are used to specify another set of minimum, maximum, and step size values.

Figure 4-6 Trapezoid conductor traces with conformal dielectrics

Bottom Ground Plane

Diel 1

Metal 2

Diel 4

Diel 2

Diel 3

Metal 1

RA 2006.03 4-7

Draft 2/6/06

Width and Spacing Parameters Raphael Tutorial

• Typically, the first set of min/max/step values is used for fine variation of the parameter of interest.

• The second set of min/max/step values is used for coarse variation of the parameter.

For example, consider the following:

cond_2 spacing 0.2 1.5 0.1 1.5 8 0.5

This line says to parametrically vary the spacing of cond_2 traces in an array, from 0.2 μm to 1.5 μm in steps of 0.1 μm (fine spacing), and then to vary the spac-ing from 1.5 μm to 8 μm in steps of 0.5 μm. Thus, spacing values of 0.2, 0.3, 0.4, … 1.3, 1.4, 1.5, 2.0, 2.5, … 7.5, and 8.0 μm are used when preparing the parasitics database. As shown in Figure 4-7, fine variation of the spacing parameter is achieved in Range 1 using the Min 1 Max 1 Step 1 design parameters. Coarse variation of the spacing parameter is achieved in Range 2 using the Min 2 Max 2 Step 2 design parameters

Note:Because the dependence on width is almost linear, it is usually enough to specify only one range and two or three width values. However, for spac-ing, it is usually necessary to specify two ranges, as shown in Figure 4-7.

Figure 4-7 Fine and coarse variation in spacing parameters for Ranges 1 and 2

4-8 RA 2006.03

Draft 2/6/06

Raphael Tutorial Width and Spacing Parameters

Note:When the simulation is started, the program checks to see if the file disc.pts exists. This file contains the exact width and spacing values for simulation. If it exists, the program ignores the min/max/step values that were entered in the Technology Characteristics window. If it does not exist, the program creates disc.pts based on the min/max/step values. By editing the file disc.pts manually, you can force the simulation at any desired combination of width and spacing.

Avoiding Generation of Excessive Combinations

When defining the width and spacing parameters, avoid generating an excessive number of combinations.

The first two generic structures are not problematical (“array above ground plane” and “array between ground planes”), since the number of combinations for those structures is (n widths) * (n spacings).

For example, if a conductor has three different widths and 27 different spacings, there are 3 * 27 = 81 width-spacing combinations. This results in the setup of 81 simulation runs, per actual structure, when you click the Automatically Create button in the Raphael Parasitics Database window (Figure 3-1, p. 3-2).

However, for the “two array structures,” it is easy to generate huge numbers of simulations, since the number of combinations for those structures is (n widths in top array) * (n spacings in top array) * (n widths in bottom array) * (n spacings in bottom array). Using the same design parameters as above, a total of 3 * 27 * 3 * 27 = 6,561 simulations could be required, per actual structure. Therefore, if in doubt, start with a small test case, using only a few width and spacing parameters.

Note:If a step size of 0 (zero) is specified, there is no contribution from that min/max/step set of values, regardless of the values of min or max. This nullifies a min/max/step set.

You may edit design parameters directly, cell by cell. Alternatively, you may copy all the technology and design parameters from one database to another database, using the copy and paste operations described in Chapter 3, Copying and Pasting Technology Characteristics, p. 3-10.

Note:When you have finished editing the design parameters, click the OK or Apply button (or File➔Save) in the Technology Characteristics win-dow to enter your changes; otherwise, these changes will be lost when you switch to a different database.

RA 2006.03 4-9

Draft 2/6/06

Loading an Interconnect Technology Format (ITF) File Raphael Tutorial

Click the Reset button to restore the parameters to the last setting established by OK or Apply. Click Cancel to cancel any changes since the last OK or Apply. OK and Cancel automatically close (dismiss) the window.

The conductor names were defined earlier in the Technology Parameters panel of the window. Move to that window panel if you wish to change a conductor name. The width and spacing cells in the Variable column serve to label the rows and cannot be edited.

Loading an Interconnect Technology Format (ITF) FileYou can optionally load the new Interconnect Technology Format (ITF) file into the Technology Characteristics window. Further description of this file format is given in Appendix G. The ITF file format is also used by Synopsys Star-RCXT product. In order to load an ITF file, execute File➔Load ITF File... in the Tech-nology Characteristics window on an unfrozen technology.

Currently, Raphael ignores certain attributes for the conductors and dielectrics described in the ITF file. The following description illustrates the attributes of the ITF file elements that are not handled by Raphael.

• Conductors that have the IS_DIFF or IS_GATE flags are ignored.

• Conductors that are local interconnects (e.g. LI and POLY layers) are considered as a single conductor with the vertical location and thick-ness corresponding to the topmost layer among this set of conductors.

• Conformal conductors (e.g. conductors with MEASURED_FROM = TOP_OF_CHIP) are considered as regular conductors and the thick-ness of the conductor is measured from the dielectric below.

• The following attributes in the CONDUCTOR statement are currently not processed by Raphael: RPSQ, RHO, CLAD_SW_T, CLAD_SIDE_WALL_RPSQ, EFFECTIVE_RPSQ_TABLE, FILL_RATIO, FILL_WIDTH, FILL_SPACING, AIR_GAP_HEIGHT, AIR_GAP_WMAX, and AIR_GAP_SMAX.

Note:The ETCH parameter is currently supported in Raphael version 2000.2.

• VIA statements are currently not processed by Raphael.

Examples of ITF Files can be found at <RA_PATH>/examples/itf_files directory.

Setting Nonplanar Technology CharacteristicsUp to now, planarized technology has been described where the z-location of each conductor layer is fixed. By disabling the Planarized Technology button in the Technology Characteristics window, the specified technology is interpreted as a

4-10 RA 2006.03

Draft 2/6/06

Raphael Tutorial Specifying the Variation of Dielectric Thicknesses

nonplanarized technology. Raphael automatically adjusts the relative positions of metal and dielectric layers for field simulation.

Figure 4-8 shows an example of the relative positions of Metal 1 to Metal 3. In the case of planarized technology, the z-distance between Metal 3 and Metal 1 is fixed. In the case of nonplanarized technology, Raphael automatically lowers Metal 3 in extracting the Metal 3 to Metal 1 capacitance. In the latter case, the dielectric layer where Metal 2 overlapped was removed.

Specifying the Variation of Dielectric ThicknessesRaphael can model the variation of interlayer dielectric (ILD) thickness between metal layers. You can build up to three separate capacitance databases (directo-ries) within a single technology directory using different dielectric thicknesses: the stdCap, minCap, and maxCap directories. These databases are constructed using the nominal (mean), minimum, and maximum interlayer dielectric (ILD) thicknesses, respectively.

Note:The total capacitance in the minCap directory is usually larger than the total capacitance in the maxCap directory. In addition, the nonpla-narized technology can be selected only for the stdCap, and not the minCap or maxCap, directory at this time.

To build a new database, or to generate a capacitance table and LPE rule files using an existing database, make sure to select the proper working directory in the User Preferences window. See Chapter 5 on choosing the target directory.

The minimum and maximum ILD thicknesses are computed from the percent (%) variation of each individual dielectric thicknesses which is specified in the Technology Characteristics window.

Figure 4-8 Nonplanarized technology vs. planarized technology

Metal 2

Metal 3

Planarized Technology

Metal 1

Metal 3

Nonplanarized Technology

Metal 1

removed

RA 2006.03 4-11

Draft 2/6/06

Specifying the Variation of Dielectric Thicknesses Raphael Tutorial

The minimum or maximum ILD thicknesses are computed by subtracting or add-ing the statistical sum of all dielectric thickness variations between the two layers of interest. Let

Equation 4-1

where:

• Δtj’s are the variations of interlayer dielectrics among metals, air, and sub-strate,

• Δttotal is the effective total variation between two layers

Then, the minimum value is computed by subtracting Δttotal from the mean value, and the maximum value is computed by adding Δttotal to the mean value.

During the capacitance computation, the dielectric profile is dynamically deter-mined. Figures 4-9 and 4-10 show the dielectric profiles for two separate struc-tures simulated with the SRAM technology: one with MET1 only and the other with POLY and MET1. The minimum values specified in Figure 4-9 are used as an example here. Each dielectric thickness is adjusted proportionally to match the target minimum ILD thickness, while the metal layer thickness remains fixed.

To be more specific, the dielectric thicknesses of Figure 4-9 are computed by the following:

• Let β = 5% variation of each layer’s thickness

• T1 = mean ILD thickness between MET1 and substrate; T2 = mean ILD thick-ness between air and MET1

• ΔT1= total variation of ILD thickness between MET1 and substrate

• ΔT2 = total variation of ILD thickness between air and MET1

Figure 4-9 The dielectric profile of MET1-above-substrate structure using the minimum ILD thicknesses of the SRAM example

Δttotal Δtj( )2

j∑=

substrate

air

MET1

0.4804

1.3453

1.4469

1.5434

diel_0

diel_1

diel_2

diel_3

Minimum Mean

0.8

0.5

1.4

1.5

1.6

0.8

4-12 RA 2006.03

Draft 2/6/06

Raphael Tutorial Specifying the Variation of Dielectric Thicknesses

• tdiel0 = adjusted diel_0 thickness; tdiel1 = adjusted diel_1 thickness, etc.

RA 2006.03 4-13

Draft 2/6/06

Specifying the Variation of Dielectric Thicknesses Raphael Tutorial

Then,

,

,

,

,

,

,

,

Notice that diel_2 has been divided into two parts to compute the ILD thickness between air and MET1. While the top part (of 1.4469) is adjusted and the bottom part (of 0.8) remains fixed.

Similarly, for Figure 4-10, you have

,

Note that tdiel2 and tdiel3 are the same as before, and in addition to diel_2, diel_1 has been divided into two parts to compute the ILD thickness between MET1 and POLY.

Figure 4-10 The dielectric profile of MET1-and-POLY-above-substrate structure using the minimum ILD thicknesses of the SRAM example

β 0.05=

T1 0.5 1.4+= T2 1.6 1.5+=

σ0.5 β 0.5×= σ1.6 β 1.6×=

σ1.4 β 1.4×= σ1.5 β 1.5×=

Q1 σ0.5 σ1.4+= Q2 σ1.6 σ1.5+=

ΔT1 σ0.52 σ1.4

2+= ΔT2 σ1.6

2 σ1.52

+=

tdiel0 0.5 ΔT1 σ0.5 Q1⁄×–= tdiel1 1.4 ΔT1 σ1.4 Q1⁄×–=

tdiel2 0.8 1.5 ΔT2 σ1.5 Q2⁄×–+= tdiel3 1.6 ΔT2 σ1.6 Q2⁄×–=

substrate

air

MET1

0.4750

1.4469

1.5434

diel_0

diel_1

diel_2

diel_3

Minimum Mean

0.8

0.5

1.5

1.6

0.8

POLY

0.9500

0.4

1.0

0.4

tdiel0 0.475= tdiel1 0.4 0.95+=

4-14 RA 2006.03

Draft 2/6/06

Raphael Tutorial Specifying the Variation of Conductor Thickness and Width

Specifying the Variation of Conductor Thickness and WidthA thickness tolerance, %Variation, also can be specified for the conductors. For conductors that have a non-zero tolerance value specified, the thickness value is decreased (minCap) or increased (maxCap) by the specified percent of the nom-inal thickness value. For example, if the thickness of the conductor is specified as 0.5 um in the stdCap case and the tolerance is specified as 10%, then the thick-ness of the conductor under minCap conditions would be 0.5 (1- 0.1) = 0.45 um and the thickness of the conductor under maxCap conditions would be 0.5 (1+0.1) = 0.55 um.

To characterize the variations in the conductor width, a width tolerance factor, %DeltaW, also is available. The value specified in this column can be positive or negative and is subtracted from the width of the conductor for all three conditions: stdCap, minCap and maxCap. It is ensured that the pitch (spacing + width) between conductors is not changed by the variation of the conductor width.

Modeling the Dishing EffectNowadays copper interconnection technology replaces old aluminum intercon-nects due to the many advantages delivered by copper in comparison to aluminum. At the same time, the copper process leads to new effects that substantially affect the resistance and capacitance of copper interconnect. These effects are referred mainly as copper dishing and oxide erosion. Due to CMP, which is an integral part of the copper process, the cross section of copper traces varies in dependence of its environment. The influence of the environment on cross section variation can be specified through the local density of the traces. Thickness variation due to the dishing effect can be included into consideration by selecting Thickness vs Den-sity button in Technology Characteristics window and by specifying four parameters, which describe this effect. This feature becomes available only if the Planarized Technology button is enabled. The density D is defined as the ratio of the trace width W and the sum of the trace width and spacing S.

Equation 4-2

It is evident that the density will vary from 0 to 1. Thickness variation are speci-fied in absolute values (microns) and can be positive or negative. To enter Thick-ness vs Density parameters, you should click the desired cell and edit the value. There are four cells:

• MinDensity and the corresponding ThickVar

• MaxDensity and the corresponding ThickVar

D WS W+--------------=

RA 2006.03 4-15

Draft 2/6/06

Modeling the Dishing Effect Raphael Tutorial

If the density for particular RPD structure is less than the value specified in MinD-ensity cell, then the trace thickness is changed to the value in the corresponding ThickVar cell.

If the density is more than the value specified in MaxDensity cell, then the trace thickness is changed to the value in the corresponding ThickVar cell.

If the density of traces for a particular RPD structure is between MinDensity and MaxDensity values, then the thickness variation of the traces is defined as the lin-ear interpolation between the values specified in ThickVar cells.

Equation 4-3

Here T is the thickness of traces for particular width and spacing. T0 is the thick-ness defined in window for this conductor layer. Dmin is the minimal density defined in RPD window, and ΔT1 is the corresponding change in thickness. Dmax is the maximal density defined in RPD window, and ΔT2 is the corresponding change in thickness. D is the density for particular structure, which is determined for each structure by using Equation 4-2.

For example, let for some structure T0 0.3 μm, W = 0.2 μm, S = 0.3 μm, and user-specified: MinDensity = 0.25, ThickVa r= -0.1, and MaxDensity = 0.5 ThickVar = 0.1. It means that density is equal to 0.4, and RPD will generate structure with trace thickness T = 0.3 + (-0.1) + (0.4-0.25) (0.1-(-0.1)) / (0.5-0.25) = 0.3 -0.1 + 0.15 * 0.2/0.25 = 0.32 μm rather than with T = 0.3 μm.

Another example, let W = 0.2 μm, S = 0.8 μm. Then density is equal to 0.2 that is less than MinDensity value (0.25). Trace thickness for this particular structure will be equal to 0.3 μm -0.1 μm = 0.2 μm.

Due to the nature of CMP, thickness of the dielectric layers also should be adjusted with the trace thickness variation. This adjustment is done automatically in the following way:

• RPD searches through the dielectric stack and defines dielectric layers having the same vertical coordinate of the top of the layer (Zmax) as the conductor layers.

• The thickness of these dielectric layers vary in a similar manner as the thick-ness of the corresponding conductor layers.

• If RPD does not find a dielectric layer with a proper Zmax for a particular con-ductor layer, then RPD will not apply a thickness variation to this conductor layer. This avoids the dishing effect for some conductor layers.

The following limitations in thickness variation modeling apply:

• RPD does not check automatically the consistency of the entered values; the user must enter the proper values.

T T0 ΔT1+= D Dmin<

T T0 ΔT1 D Dmin–( )ΔT2 ΔT1–

Dmax Dmin–------------------------------+ +=

T T0 ΔT2+= D Dmax>

4-16 RA 2006.03

Draft 2/6/06


• The dishing effect can be used only with the standard Raphael templates and by no means with user-defined templates. RPD does not check automatically the user-defined templates.

• The dishing effect cannot be used with conformal dielectric layers. RPD is not checking automatically the existence of conformal dielectric layers.

• The dishing effect cannot be used for modeling process variation (minCap and maxCap). RPD does not check automatically the selected database (std-Cap, minCap, or maxCap).

Menu BarThe menu bar at the top of the Technology Characteristics window contains File, Edit, and Models menus.

Load an Interconnect Technology Format (ITF) File into the Technology Charac-teristics window by executing File➔Load ITF File.... ITF File format is described in greater detail in Appendix G.

Save the technology characteristics by executing File➔Save. This generates a .tch file in the appropriate directory of the database. In this way, the desired character-istics are consistent from session to session.

Note:Once the database is set up (“frozen”) in the Select Structures window, the Save option in the Technology Characteristics window is disabled and you cannot modify the characteristics.

Editing operations only apply to the Technology Parameters panel of the win-dow.

• To create a new conductor, execute Edit➔Conductors➔New. A new conduc-tor is added to the top of the list.

• To remove a conductor, click to select the conductor you want to remove, then execute Edit➔Conductors➔Cut.

• To copy a conductor, select the conductor you want to copy, then execute Edit➔Conductors➔Copy.

• To paste a previously cut or copied conductor, click to position the insertion point, then execute Edit➔Conductors➔Paste. The pasted conductor is inserted above the conductor you selected.

RA 2006.03 4-17

Draft 2/6/06

References Raphael Tutorial

• Similar new/cut/copy/paste operations may be performed on dielectrics.

The Models menu (Figure 4-11) allows you to generate a summary file that con-tains empirical equations of certain capacitance components described in Appen-dix A, using either Sakurai (Reference [1]) or Chern (Reference [2]) models. This summary file can be used as a reference guide. Because these empirical models have many limitations (Reference [3]), you still need to perform field-solver simu-lations to generate accurate capacitance tables or LPE models.

References[1] T. Sakurai and K. Tamaru, “Simple Formulas for Two- and Three-Dimen-

sional Capacitances,” IEEE Trans. Electron Devices, Vol. ED-30, No.2, Feb. 1983, pp. 183-185.

[2] J.H. Chern, J. Huang, L. Arledge, P. C. Li, and P. Yang, “Multilevel Metal Capacitance Models for CAD Design Synthesis Systems,” IEEE Electron Device Letters, Vol. 13, No. 1, Jan. 1992, pp. 32-34.

[3] C. C. Huang, K. S. Oh, S. L. Wang, and S. Panchapakesan, “Improving the Accuracy of On-Chip Parasitic Extraction,” 6th IEEE-EPEP, San Jose, CA, Feb. 1997, pp. 42-45.

Figure 4-11 Models menu in the Technology Characteristics window

4-18 RA 2006.03

Draft 2/6/06

CHAPTER 5

R

4. User

Preferen

ces

User Preferences Notebook5

OverviewIn this chapter, you will learn the process of setting preferences. You set prefer-ences on the desired structures in the parasitics database for the following:

• Selecting

• Simulating

• Performing regression analysis

• Modeling process variations

Each database has a set of preferences that must be set independently. It is espe-cially useful to set the user preferences before generating a parasitics database with the automatically create mode (Refer to “Fully Automatic Method,” p. 3-5).

Note:You can skip this chapter unless you wish to import your own template files to model customized structures.

Choosing Database NamesBefore setting preferences, choose a database. In the Raphael Parasitics Database window:

1. Click the desired database name from the list displayed in the Select a database panel.

2. In the Raphael Parasitics Database window menu bar, execute Options➔User preferences to open the User Preferences notebook for the specific database (Figures 5-1 through 5-3).

A 2006.03 5-1

Draft 2/6/06

Setting Preferences Raphael Tutorial

Setting PreferencesThe preferences can be set in three different areas, which appear on four distinct pages:

1. Structures: Use this page for selecting appropriate structures in the parasitics database generation.

2. Simulation: Set the options required for performing field solver simulations on the structures you selected.

3. Regression: After simulation, perform regression analysis on the structures. Use the options from the Regression page to set up preferences for regres-sion analysis.

4. Process: Currently, use this page to switch the working or target capacitance database (directory). Three separate capacitance databases can be built to model the effect of different dielectric thicknesses.

Structures Page

By default, only 2D structures are considered during the automatic generation of a parasitics database. In the Structures page, you can specify additional 3D struc-tures to be simulated during automatic database generation.

StructuresSelection

Since the simulation of 3D structures takes significantly longer than 2D structures, to obtain LPE rule decks quickly, first perform simulation without 3D structures. By default, unless the option for modeling the perimeter coefficient is set to use 3D structures (models), 3D simulation results are not used by the LPE Tools Inter-face to generate rule decks. See Chapters 8 through 10 for discussion of the LPE Tools Interface.

Additional 3D structures can be selected and simulated with or without a top ground plane (or incrementally) if necessary.

Note:Most LPE tools do not identify 3D crossovers. Invoking the 3D simula-tions here does not necessarily improve the final LPE results.

Note:Since no additional simulation will be performed for structures that have already been simulated, it is safe to select the 2D structures a second time with 3D structures.

5-2 RA 2006.03

Draft 2/6/06

Raphael Tutorial Setting Preferences

R

4. User

Preferen

ces

ExtractingCapacitances for

Two-ArrayStructures

Two-array structures (i.e. parallel array above ground plane, array cross-over above ground plane, etc.) have the option of obtaining capacitances for the top array, the bottom array, or both. By selecting one of the three options available in the Simulations for two array structures panel of the Structures page, you can obtain the desired capacitances.

Note:If you choose the Extract top conductor only or the Extract bottom conductor only option, the capacitances originating from the conductor that is not being extracted will default to the very low value of 1e-12 fF/um. For example, when the “parallel array above ground plane” generic structure is used with the Extract top conductor only option selected, the bottom array capacitances (i.e. Cbtot, Cbcou, Cbbgp, Cbtcc) will default to 1e-12fF/um.

PreviewingStructures

To preview the structures selected for the database creation process, click the Automatically Create button in the Raphael Parasitics Database window. Choose the Preview option in the popup window.

Further details on previewing the structures for simulation are described in Chapter 3.

Figure 5-1 Structures page of the User Preferences notebook for sram database

A 2006.03 5-3

Draft 2/6/06


Simulation Page

5. The Simulation page follows the preferences that are set for running field solver simulations on the selected structures. To choose the Simulation page, click the Simulation tab in the User Preferences notebook (Figure •).

.

Simulation Input/Output Files

This section of the Simulation page sets up the options for the simulation input and output files.

There are three options in the Simulation input/output files section:

• To automatically delete the input files following simulation, click Automatically delete input files after simulation.

• To delete the output files following simulation, click Automatically delete output files after simulation.

• To obtain a listing of the input file in the generated output file, click Echo input file contents in the output file.Simulation page of the User Prefer-ences notebook for sram database

Figure 5-2 Simulation page of User Preferences notebook (sram database

5-4 RA 2006.03

Draft 2/6/06


R

4. User

Preferen

ces

Note:In general, you need not change the settings in the Simulation input/output files section unless you want to load your own field solver tem-plates (see Appendix E) and view the resulting Input/Output files.

AdditionalCommand-Line

Options

Additional command-line options can be specified for the RC2 and RC3 solvers. Use this functionality to invoke the new boundary element method (BEM) solver:

1. To specify additional command -ine options for the RC2 solver, click the RC2 button

2. Enter the options in the cell next to it.

3. To invoke the BEM solver, select the 2D BEM Solver button.

4. To invoke the 2D BEM solver, select the RC2 option; -b “-s M”, is auto-matically added to the command line for RC2 before the simulation.

Note:The default for the finite-difference solver is always used for the 2D oversize structure and cannot be overridden.

1. Similarly, to specify additional command-line options for the RC3 solver, click the RC3 button and enter the options in the cell next to it.

2. If you have Raphael-NES, you also can use the QuickCAP solver for the 3D simulation by selecting the QuickCAP Solver button. Then, instead of

raphael rc3 <additional options>input_file_name

the following UNIX command line is issued during simulation:

raphael rc3 -q “-0 -matrix -numeric -s 15 -g1%” -a <additional options> input_file_name

The above commands limit each QuickCAP simulation to at most 15 CPU seconds, within which the desired accuracy may not be reached. To override the above to 30 CPU seconds, for example, enter the following in the RC3 command-line options:

-q “-0 -matrix -numeric -s 30 -g1%” -a

When the program sees the -q flag, it invokes ranes instead of raphael rc3.

Note:Because the 3D crossover structures are simple and the setup files fully exploit the symmetry, the default of the finite-difference solver often out-performs the QuickCAP solver in this case. The latter is recommended only for comparison here. Though not recommended, you can use the flag -b “-s BB” to invoke RC3-BEM.

A 2006.03 5-5

Draft 2/6/06


Note:The default options for the solvers are -z, -u, and -n. You can add other options following the above procedures. For a detailed list of available options, refer to the Raphael Reference Manual.

Templates forGeneric

Structures

This section of the Simulation page enables you to select the directory used to load the field solver templates associated with the generic structures.

1. To load the field solver templates from a desired directory, click User-defined directory.

2. Specify the directory in the text field.

3. Choose the default field solver templates by clicking Standard Raphael templates.

Appendix E explains the concept of field solver templates in more detail.

Regression Page

The third page in the User Preferences notebook is the Regression page (Figure 5-3) that enables you to choose options for performing regression analysis on the simulated structures.

Figure 5-3 Regression page of User Preferences notebook (sram database)

5-6 RA 2006.03

Draft 2/6/06


R

4. User

Preferen

ces

1. To set preferences for regression analysis, click the Regression tab in the User Preferences notebook .

Location ofDefault Models

Each LPE tool has a default regression model (.drm) file with matching models used as the default during regression analysis.

1. Indicate the Location of Default Models by clicking either a or b:

a. Standard Raphael directory

b. User-defined directory

2. Then specify the directory where the .drm files are located.

Appendix C discusses how to specify the required models in the .drm files.

Note:If the .drm files are not found in the specified user-defined directory, the default files are written to the User-defined directory.

Location of User-Defined

Equations

Raphael allows user-defined equations for performing regression analysis.

1. Specify the Location of user-defined equations by clicking either a or b:

a. Standard Raphael directory

b. User-defined directory:

2. Enter the location of the user-defined equations in the field associated with User-defined directory.

Note:If user-defined equation files are not found in the User-defined direc-tory, the default equation files are written to the User-defined directory.

ForcingRegression

Using DefaultModels

Once the regression analysis has been performed on selected structures, if you attempt to redo the regression analysis, Raphael ignores the selected structures. To prevent this and to force regression analysis on the selected structures, select the Force regression using default models button. This can be useful under cir-cumstances where you:

1. Specify a different User-defined directory for either default regression mod-els or user-defined equations.

2. Change a user-defined equation and wish to redo the regression analysis.

Process Page

The last page in the User Preferences notebook is the Process page. In this page, you can select the current capacitance database (directory) (Figure 5-4). There are three capacitance databases within a single technology directory, and they are organized into the stdCap, minCap, and maxCap directories.

A 2006.03 5-7

Draft 2/6/06


Each of these databases can be associated with different interlayer dielectric thick-nesses:

• Nominal (mean) thickness for stdCap

• Minimum thickness for minCap

• Maximum thickness for maxCap

See “Specifying the Variation of Dielectric Thicknesses,” p. 4-11 for more details on modeling the variation of interlayer dielectric thicknesses.

Applying Preference Settings

1. To apply the modified preference settings to the selected database, in the User Preferences notebook, click the Apply or OK button.

2. To return to the default settings, click the Defaults button.

3. To apply the default preferences, click the Apply or OK button again.

4. To cancel the modifications, click the Cancel button.

Figure 5-4 Process page of User Preferences notebook (sram database)

5-8 RA 2006.03

Draft 2/6/06

CHAPTER 6

R

5. Man

ual

Mo

de

Manually Creating Parasitics Database6 OO

OverviewThis chapter explains how to:

• Select structures that are relevant to a database

• Set up the structures for simulation

• Determine the difference between generic and actual structures

• Run field solver simulations

• Optionally perform regression analysis (curve-fitting) on the results

• Generate a printed report of regression analysis

Note:Discussion in this chapter applies only to building the parasitics data-base manually. The majority of users can skip this chapter because they can build a database with the automatic method. See “Fully Automatic Method,” p. 3-5 for details.

Setting up the Structures for SimulationThis section describes how to select structures and set up directories for simula-tion.

Starting from versions 2002.2, Raphael allows to simulate the generic structures based on arrays with three or five traces, as well as with different trapezoidal cross-section of traces from different conductor layers. The default set of generic structures handles structures with three traces’ arrays and rectangular shape of the trace cross-section. This set automatically supports an arbitrary number of confor-mal dielectric layers for any generic structure. In addition to standard generic

A 2006.03 6-1

Draft 2/6/06

Setting up the Structures for Simulation Raphael Tutorial

structures there are three customized sets of generic structures that handle generic structures with five traces (Conformal5 and Trapezoid5) and trapezoidal shapes of traces (Trapezoid3 and Trapezoid5). All customized generic structures support up to two conformal dielectric layers for each conductor layer. Customized generic structures can be loaded by using the Simulation page in User Preferences note-book by selecting User-defined directory to load the proper field solver tem-plates associated with the generic structures. The field solver templates for customized generic structures are located at the following directories:

<RA_PATH>/rpd/Conformal5

<RA_PATH>/rpd/Trapezoid3

<RA_PATH>/rpd/Trapezoid5,

The particular trapezoid shape is defined by parameters ratio_top and ratio_bot for two-array generic structures or by parameter ratio_top for one-array generic structures. These parameters determine the relative variation in the top width with respect to the bottom width. The default value of these parameters is 0.1. The default value can be changed by using Additional command line options on Simulation page of User Preferences notebook. For example, entering the fol-lowing in the RC2 command-line options:

-P”ratio_top=0.4”

the value of parameter ratio_top will be changed from default 0.1 to 0.4 for all two-dimensional generic structures. If you want to use customized generic struc-ture, define the proper directory as it is described above and specify desired trape-zoid shape if you chose generic structures wit trapezoid cross section of traces.

In contrast to previous releases, current Raphael version allows to characterize interconnect structures that are inherent to TFT/LCD designs. For this purpose Raphael generic structures were extended with new customized structures that can be loaded by using the Simulation page in User Preferences notebook by select-ing User-defined directory to load the proper field solver templates associated with the generic structures. The field solver templates for customized generic structures are located at the following directories:

<RA_PATH>/rpd/TFT1, <RA_PATH>/rpd/TFT2, <RA_PATH>/rpd/TFT3, <RA_PATH>/rpd/TFT4 and <RA_PATH>/rpd/TFT5

Detail description of the new generic structures can be founded in Appendix H.

Selecting Generic Structures

To manually create a parasitics database, the first step is to select relevant struc-tures for a target database. To open the Select Structures window (Figure 6-1) in

6-2 RA 2006.03

Draft 2/6/06

Raphael Tutorial Setting up the Structures for Simulation

R

5. Man

ual

Mo

de

the Raphael Parasitics Database window, click the Select… button (See Chap-ter 3, Figure 3-1, p. 3-2).

The Select Structures window contains on-screen instructions as follows:

• Select generic structure from a list of available structures.

• Export generic structures results in a set of actual structures formed by con-sidering all possible combinations of conducting elements, actual top and bot-tom ground planes, and effective top and bottom ground planes (formed by a dense array of traces).

• Select desired actual structures of interest for your database.

• Set up selected actual structures for simulation.

Regardless of the technology you are viewing, the generic structures in the Select Structures window are always the same. However, actual structures generated during the export process depend on the technology selected.

Generic Structure Types

Raphael provides the following generic interconnect structures:

• Array of traces above a ground plane

• Array of traces between two ground planes

• Parallel arrays of traces above a ground plane

• Parallel arrays of traces between two ground planes

Figure 6-1 Select Structures window showing first two generic structures selected and exported, forming actual structures for the sram database

A 2006.03 6-3

Draft 2/6/06


• Array crossover above a ground plane

• Array crossover between two ground planes

• Coincident edge structure above a ground plane

• Coincident edge structure between two ground planes

• Oversize structure between two ground planes

• Different layers above a ground plane

• Different layers between two ground planes

These structures appear in the Generic Structures panel on the left side of the Select Structures window.

1. To select the generic structures, click the appropriate icons in the GenericStructures column.

2. To select more than one structure, click-drag-release with the mouse.

3. To change the set of structures selected, press and hold the Control key, then click the Select mouse button on the desired structures.

Generic Structures Properties

The first four generic structures contain the following properties:

• Structures are two-dimensional (2D simulations are performed).

• The center trace is biased when simulation is performed.

• Each array contains three traces.

The next two generic structures (array crossover above ground plane, and array crossover between ground planes) share the following properties:

• Structures are three-dimensional (3D simulations are performed).

• The center trace is biased when the simulation is performed.

• Each array contains three traces; however, a reflecting boundary condition is imposed. The resulting simulated structure consists of n traces in each array, where every third biased trace is separated by two unbiased traces.

• The top or the bottom array of traces is biased depending on the array to be extracted. Choose the array from the Simulation page of the User Preferences notebook.

The next two generic structures (coincident edge above ground plane and coinci-dent edge between ground planes) have the following properties:

• Structures are two-dimensional (2D simulations are performed).

• There are two arrays of conductors and each array contains two traces. How-ever, the width and spacing of the top array is used for both arrays.

• The top right trace is biased when simulation is performed.

6-4 RA 2006.03

Draft 2/6/06


R

5. Man

ual

Mo

de

The next generic structure in the palette is the oversize structure between ground planes, which has the following properties:

• Structure is two-dimensional (2D simulations are performed).

• There is a single array of conductors between two ground planes that contains two traces.

• The trace on the right is biased when simulation is performed.

The last two generic structures in the palette (different layers above ground plane and different layers between ground planes) have the following properties:

• Structure is two-dimensional (2D simulations are performed)

• There are two arrays of conductors and each array contains two traces. Spac-ing between two traces in the same array is fixed at the average spacing dis-tance. Spacing between the top left trace to the bottom right trace varies from zero to the maximum spacing distance specified for the bottom conductor layer (see Figure 6-2).

• The trace on the top left is biased when simulation is performed.

For all generic and actual structures, a ground plane may be a true physical ground plane (substrate), or an effective ground plane, formed by a dense array of traces above or below the array of interest.

1. To display the Raphael field solver template representing the structure in the corresponding field solver syntax, double click on the desired generic struc-ture icon in the Generic Structure panel of the Select Structures window.

A Terminal window displaying the structure description will open.

Figure 6-2 Different layers above a ground plane generic structure

Metal 1

Metal 2

Biased Trace

s = 0 to smax of Metal 1

savg of Metal 2

savg of Metal 1

A 2006.03 6-5

Draft 2/6/06


If you choose a user-defined field template directory to load your own struc-tural description for the generic structures, you can edit and save the contents of the terminal window to update the structure description.

Figure 6-3 Contents of the field solver template displayed by double-clicking the arr_above_gp generic structure icon in the Select Structures window

6-6 RA 2006.03

Draft 2/6/06


R

5. Man

ual

Mo

de

Exporting Generic Structures to Create Actual Structures

To export the generic structures you selected earlier (“Selecting Generic Struc-tures,” p. 6-2), click the Export button in the Select Structures window.

For every generic structure you selected before clicking the Export button, an entire row of actual structures is displayed in the Actual Structures panel of the Select Structures window. Actual structures are formed by considering all possi-ble combinations of conducting elements and top and bottom ground planes.

For example, Figure 6-1, p. 6-3 shows some of the actual structures exported from the generic structures palette for the sram database.

The technology characteristics displayed in Chapter 4, Figure 4-1, p. 4-2 show that the sram database has three conducting layers: MET2, MET1, and POLY.

The following six combinations represent all possible combinations of an array of traces above a ground plane (either a physical ground plane or an effective ground plane) for these three conducting layers:

• POLY traces above substrate (a physical ground plane)

• MET1 traces above substrate

• MET1 traces above an effective ground plane formed by dense POLY traces

• MET2 traces above substrate

• MET2 traces above dense POLY traces

• MET2 traces above dense MET1 traces

The six actual structures in the top row of Figure 6-1, p. 6-3 correspond to the six combinations listed above. For the second generic structure, there are only four possible combinations:

• POLY between MET1 and substrate

• POLY between MET2 and substrate

• MET1 between MET2 and substrate

• MET1 between MET2 and POLY

The second row of Figure 6-1, p. 6-3 shows four actual structures.

A 2006.03 6-7

Draft 2/6/06

Performing Manual Simulation Raphael Tutorial

Selecting Actual Structures and Performing Simulation

1. Select the actual structures of interest for your technology by clicking the appropriate icons in the Actual Structures panel of the Select Structures window.

2. To select more than one structure, click-drag-release with the mouse. To change the set of structures that are selected, press and hold the CONTROL key, then click the mouse button on the desired structures.

3. After selecting the desired actual structures, click the Setup button in the Select Structures window.

All necessary files and directories are set up automatically.

Information about the files and directories created is displayed in the UNIX window from which you started Raphael.

Note:You must click the Setup button after selecting the actual structures; otherwise, no files or directories will be prepared

CAUTION

• Simulations are not run until you click the Automatically Create button in the Raphael Parasitics Database window, or click the Create Data-base or Run Simulations buttons in the Create/Inspect Parasitics Da-tabase window.

• Once the Setup button is clicked, however, the database is frozen and the technology characteristics cannot be modified. The parameters in the Technology Characteristics window appear as red text to indicate “frozen” status.

Performing Manual SimulationOnce the directory has been set up for the selected structures, you can perform the field simulation manually.

1. Open the Create/Inspect Parasitics Database window by clicking the Man-ually Create… button in the Raphael Parasitics Database window. See Chapter 3 for full details on the Raphael Parasitics Database window.

The Create/Inspect Parasitics Database window shows structures for the database you selected in the Raphael Parasitics Database window (see Figure 6-4, p. 6-9).

2. To display structures for a different database, click the desired database name in the Raphael Parasitics Database window.

3. Use the Create/Inspect Parasitics Database window to:

a. Run field solver simulation

6-8 RA 2006.03

Draft 2/6/06

Raphael Tutorial Actual Structures

R

5. Man

ual

Mo

de

b. Perform regression analysis (curve-fitting) on the results

c. Generate a printed report

Actual StructuresThe Actual Structures portion of the Create/Inspect Parasitics Database win-dow (Figure 6-4) shows various structures that were previously selected for simu-lation. This selection process, and the exact meaning of each of the actual structures, is detailed in the previous section. At this time, note the following:

• The top row of structures in Figure 6-4 contains specific instances of the generic structure array of traces above a ground plane.

• The second row contains a specific instance of the generic structure array of traces between two ground planes.

• The third row contains a specific instance of the generic structure parallel arrays of traces above a ground plane.

Figure 6-4 Create/Inspect Parasitics Database window, showing structures for the sram database

A 2006.03 6-9

Draft 2/6/06

Running Simulations and Regression Analysis Raphael Tutorial

Consider the structure in the second row of Figure 6-4, p. 6-9. Each line of text has the following meaning:

To display structures for a different database, click the desired database name in the Raphael Parasitics Database window (Figure 3-1, p. 3-2). Notice that both the Technology Characteristics window (Figure 4-1, p. 4-2) and the Create/Inspect Parasitics Database window (Figure 6-4, p. 6-9) are updated automatically.

Selecting Actual Structures

If the Actual Structures portion of the Create/Inspect Parasitics Database window is empty, it is because no actual structures have been set up for simula-tion. The previous section on “Setting up the Structures for Simulation,” p. 6-1 explains how to do this. In particular, you must click the Setup button in the Select Structures window; otherwise, no simulation files or directories will be prepared.

• You can click the Create Database button (or Run Simulations or Run Regression buttons) in the Create/Inspect Parasitics Database window if the selected actual structures have already been processed. Messages are dis-played in the UNIX window from which you started Raphael, indicating that the field solver simulations or regression analysis have already been run.

Running Simulations and Regression AnalysisTo run field solver simulations and regression analysis using the Create/Inspect Parasitics Database window:

1. Select the actual structures you wish to analyze by clicking the appropriate icons in the Actual Structures portion of the window.

a. To select more than one structure, click-drag-release with the mouse.

b. Change the set of structures that are selected by pressing and holding the CONTROL key, then clicking the mouse button on the desired structures.

2. Click the Create Database button (or click the Run Simulations button fol-lowed by the Run Regression button).

• The Create Database button automatically runs the field solver simu-lations and then performs batch regression analysis for all the selected

#1 of 4 This is the first of four selected structures of this generic type.

MET1 The top ground plane is a dense array of MET1 traces.

POLY The POLY layer width and spacing are parametrically varied (per min/max/step parameters in Chapter 4, “Width and Spac-ing Parameters,” p. 4-7).

substrate The bottom ground plane is the silicon substrate.

6-10 RA 2006.03

Draft 2/6/06

Raphael Tutorial Running Simulations and Regression Analysis

R

5. Man

ual

Mo

de

actual structures. (This is equivalent to clicking the Run Simulations button and then clicking the Run Regression button.)

• The Run Simulations button only runs field solver simulations for the selected structures.

• The Run Regression button only runs batch regression analysis for the selected structures. See Chapter 7 for information about regression analysis.

Note:You do not have to run all the simulations or regression analyses at once. First, select a single actual structure, click Run Simulation and Run Regression, and inspect those results. Then, select additional structures and click Run Simulation and Run Regression again.

• All the necessary input and output files and directories are automatically pro-cessed for you. Status information generated as the field solver simulations and regression analysis proceeds is displayed in the UNIX window from which you started Raphael.

• The status of the simulation is displayed in the Raphael Status Dialog which opens when the Run Simulations button is clicked. This dialog displays the information about the generic structure, the actual structure and the current field solver file being simulated.

1. To abort an on-going simulation, click on the Cancel button on the Raphael Status window. This terminates the current simulation, and removes the gen-erated results for the current actual structure being simulated.

If you try to redo the regression analysis once it has been performed on the selected structures, Raphael skips the structures.

2. To prevent skipping structures, select the Force regression using default models button in the Regression page of the User Preferences notebook to forcibly perform regression on selected structures. Refer to Chapter 5 for details. This forced regression analysis can be useful under circumstances where you:

a. Specify a different User-defined directory for either default regression models or user-defined equations.

b. Change a user-defined equation and wish to redo the regression analysis.

Figure 6-5 Raphael Status window displaying the status of the current field solver simulation.

A 2006.03 6-11

Draft 2/6/06

Tool Kit Raphael Tutorial

Note:The LPE Tools Interface does not use regression information at all; regression analysis is purely optional.

Tool KitThe Tool Kit contains various tools for visualizing results and performing regres-sion analysis (curve fitting) for any of the actual structures. To use a tool, select the structure of interest, then double-click the tool icon (see Chapter 7).

• The Regression tool performs regression analysis and obtains models (equa-tions) expressing capacitance as a function of width and spacing.

• The Cap vs Width and Cap vs Space tools display plots of capacitance vs. width and capacitance vs. spacing for any selected actual structure.

• The Report tool generates a printed report summarizing the database and the analysis performed by Raphael.

Menu Bar

The menu bar at the top of the Create/Inspect Parasitics Database window con-tains two menus: File and Edit.

Options available to you from the menu bar include:

• Execute File➔Close to close the window.

• Execute Edit➔Delete selected structures to completely remove the struc-tures you have selected.

CAUTIONThe Edit➔Delete selected structures operation is not reversible. This op-eration results in the permanent removal of all field solver simulation results and all regression analysis results for all of the selected structures. If you do not want to remove the structures and lose the results, select the Cancel but-ton in the popup window. After you click the OK button in the popup window, it may take a minute or

6-12 RA 2006.03

Draft 2/6/06

Raphael Tutorial Tool Kit

R

5. Man

ual

Mo

de

longer for Raphael to complete the deletion. During this time, Raphael is un-available for other operations..

Figure 6-6 Popup window for Edit➔Delete selected structures

A 2006.03 6-13

Draft 2/6/06

Tool Kit Raphael Tutorial

6-14 RA 2006.03

Draft 2/6/06

CHAPTER 7

R

6.Utiilities

Man

ual D

B

Utility Tools For Manual Database Generation7

Overview

Note:Tools described in this chapter can be used only during the manual cre-ation of the parasitics database. Most users can skip this chapter.

The following three sections of this chapter describe three utility tools used during the manual mode of parasitics data base generation:

1. Regression analysis tool

2. Regression report generator

3. Plotting tool for capacitance curves

To duplicate the results shown in this tutorial, make sure the Create/Inspect Parasitics Database window displays structures for the sram database.

To display information about a different database, click the desired database name in the Raphael Parasitics Database window.

A 2006.03 7-1

Draft 2/6/06

Using Regression Analysis Tool Raphael Tutorial

Using Regression Analysis Tool

Note:Regression analysis is not necessary for generating rule decks for LPE tools.

This section teaches you to:

• Select the structures for regression analysis from an existing parasitics data-base.

• Perform regression analysis.

• Obtain rules (models or equations) for expressing capacitance as a function of width and spacing for a selected actual structure.

To select structures for regression analysis, refer to the Raphael Parasitics Database window (Figure 3-1, p. 3-2) and Create/Inspect Parasitics Database window (Figure 6-1, p. 6-3).

Key ConceptsTwo key concepts govern the Raphael regression analysis capabilities:

• Fully automatic batch regression analysis vs. manual regression analysis.

• Raphael-defined equations vs. user-defined equations.

Batch vs. ManualRegression

Use Raphael to perform fully automatic batch regression for one or more selected structures:

1. Choose the appropriate default models to be used while performing batch regression in the Regression page of the User Preferences notebook. (See “Regression Page,” p. 5-6 in Chapter 5.)

2. Select the desired structures in the Create/Inspect Parasitics Database win-dow (Figure 6-4, p. 6-9).

3. Click the 2. Run Regression button. See “Batch Regression Analysis,” p. 7-9 for details.

Manual regression analysis for a selected structure gives you more control over the process:

1. Select the desired structure in the Create/Inspect Parasitics Database window (Figure 6-4, p. 6-9).

2. Double-click the Regression tool to open the Regression Analysis window. See “Manual Regression Analysis,” p. 7-3 for details.

7-2 RA 2006.03

Draft 2/6/06

Raphael Tutorial Manual Regression Analysis

6.Utiilities

Man

ual D

B

Note:Before you attempt to run regression analysis (either manually or in batch mode), the field solver simulations for the selected structures must already be complete.

Raphael-Definedor User-Defined

Equations

The program supplies a number of Raphael-defined equations or models. They are built into Raphael, and are described in Appendix B: Regression Analysis Model Definitions, at the end this tutorial.

Note:You cannot modify these equations.

Instead of using Raphael-defined equations, you may define your own and use them for regression analysis. User-defined equations can include a wide variety of mathematical functions, such as sin, cos, exp, log. See “User-Defined Equations,” p. 7-11 for details.

Manual Regression Analysis

Note:Even if your main interest is batch regression analysis, review this sec-tion for background information on Raphael regression analysis.

1. To duplicate the results shown in this tutorial, make sure the Create/InspectParasitics Database window displays structures for the sram database.

2. To display information about a different database, click the desired database name in the Raphael Parasitics Database window.

3. To manually run a regression analysis:

a. In the Raphael Parasitics Database window, click Create Database.

b. Click a structure directly in the Create/Inspect Parasitics Database window to select it. To duplicate the results shown in this tutorial, click the MET1 above substrate structure in the first row (see Figure 6-4, p. 6-9.)

c. After selecting a structure, double-click the Regression tool icon in theCreate/Inspect Parasitics Database window to open the Regression Analysis window.

Figure 7-1 Structure to select in the sram database

RA 2006.03 7-3

Draft 2/6/06

Manual Regression Analysis Raphael Tutorial

d. After selecting a structure, double-click the Regression tool icon in theCreate/Inspect Parasitics Database window to open the Regression Analysis window (Figure 7-2).

Using the Regression Analysis Window

The Regression Analysis window, shown in Figure 7-2, is used for manual regression analysis for a single structure.

Figure 7-2 Regression Analysis window, for manual regression analysis of a single structure

7-4 RA 2006.03

Draft 2/6/06


6.Utiilities

Man

ual D

B

Overview The main elements of the Regression Analysis window are:

• A menu bar (see “Menu Bar,” p. 7-15)

• A Selected structure text field that briefly describes the structure you selected in the Create/Inspect Parasitics Database window:

Array above ground plane#2 of 6: MET1 above substrate

• Panel 1. Select a Target shows all the capacitance terms defined for the selected structure. These terms are described at the end of this tutorial in Appendix A: Capacitance Definitions of Raphael Default Database.

• Panel 2. Select a Model lists all the regression equations available for the selected structure. Raphael-defined equations, such as Mono decreasing, are described in Appendix B. User-defined equations, such as User defined Ia, are described in “User-Defined Equations,” p. 7-11.

• The Equation for the selected model text field contains the applicable equa-tion for the selected model. If the equation is Raphael-defined, the Not Edit-able label above the panel is highlighted. If the equation is user-defined, the Editable label is highlighted.

• The large panel 3. Toggle “extract” vs. “fix” shows information about each parameter in the selected model. Use this panel to specify which terms in the equation to include (“extract” for regression) and which terms to exclude (“fix”) for the extraction.

• A Run… button in panel 4. Run & Plot Regression Analysis automatically displays a plot of regression analysis results.

• A Table… button in panel 5. View Results displays a table of regression anal-ysis results.

Selecting Targetsand Models

In the Select a Target panel of the Regression Analysis window, different tar-gets appear in the list, depending on the generic structure selected. For precise, structure-specific definitions of the terms such as C total and C coupling, see Appendix A in this tutorial.

1. Click to select the desired target from the list.

2. For this example, select C total. Whenever you select a target, the recom-mended default model is automatically selected for you. For example, when you select C total, the Mono decreasing model is automatically selected and displayed.

3. You may override the default model by clicking in the Select a Model list. The Raphael-defined models are described in Appendix B. The user-defined models are described in “User-Defined Equations,” p. 7-11.

Extract vs. Fix Now that you have selected a structure, target, and model, the large panel labeled Toggle “Extract” vs. “Fix” updates to display information about the parameters for this selection.

RA 2006.03 7-5

Draft 2/6/06


1. Click cells in the First Pass column to toggle between Fix and Extract.

2. To include a parameter in the regression analysis, set the corresponding cell to Extract.

3. To exclude a parameter from the regression analysis, set the corresponding cell to Fix.

4. To use all the terms in the model, set all the cells in the First Pass column to Extract.

You may find that in certain cases, superior results are achieved by extracting some, not all, of the parameters. The fewer the parameters you extract, the simpler the resulting expression.

Running aManual

RegressionAnalysis

After selecting a structure, target, and model, and setting the Fix/Extract cells as desired, click the Run… button to run the regression analysis. A plot of regression analysis (Figure 7-3) displays results corresponding to the raw data in Figure 7-2 (total capacitance versus the spacing of traces in an array of MET1). You may also view a tabular summary of results. See “Tabular Results,” p. 7-7 for details.

GraphicalResults

A window containing a plot of regression analysis results (Figure 7-3) opens after the manual regression analysis is complete. This takes less than a minute. For very complex models with many data points (i.e., field solver simulation runs), regres-sion analysis may take as long as 10 or 15 minutes.

If the wait for the plot window to appear is very long, or if there are error mes-sages in the UNIX window from which you started Raphael, see your UNIX sys-tem administrator or the person who installed Raphael on your system.

Note:A plot of regression analysis results only appears during manual regres-sion analysis. Such plots do not appear during batch regression analysis.

7-6 RA 2006.03

Draft 2/6/06


6.Utiilities

Man

ual D

B

Tabular Results After a regression analysis run is complete, click the Table… button in the Regression Analysis window to display a table of results.

If the Regression Analysis Results window is already open, it automatically updates each time you select a different combination of structures, targets, or models. If you run a regression analysis, the window updates after the analysis is complete and the plot window has opened.

The main elements of the Regression Analysis Results window include the fol-lowing:

• RMS error: field is a noneditable text field showing the percent root mean square (RMS) error, a criteria for assessing the quality of fit for regression analysis. The lower the value, the better the fit.

• Regression Analysis Results window shows only results for those parame-ters that have been extracted, as specified by the Extract/Fix setting. See “Extract vs. Fix,” p. 7-5 for details.

• Final Value column shows the best value obtainable for each parameter.

Figure 7-3 Plot of regression analysis results

RA 2006.03 7-7

Draft 2/6/06


• At limit? column is normally blank. If one or more of the regression analysis parameters reaches one of its minimum or maximum values (shown in Figure 7-2), the word LIMIT appears in that cell parameter.

In this version of the program, you have no control over this issue—it is for your information only. The more parameters that reach a limit, the poorer the curve fit is likely to be. The regression results may be satisfactory even if one or more parameters reaches a limit.

• Initial value column shows the starting value that was used for each parameter at the beginning of the iterative regression analysis.

• % Change column shows the percentage of change in the parameter value, from the initial value to the final value.

Note:You can easily generate a report containing the regression analysis results appearing in Figure 7-4. See “Report Generator for Regression Results,” p. 7-15 for details.

Figure 7-4 Regression Analysis Results window

7-8 RA 2006.03

Draft 2/6/06

Raphael Tutorial Batch Regression Analysis

6.Utiilities

Man

ual D

B

Batch Regression Analysis

Note:See “Manual Regression Analysis,” p. 7-3 for important background information regarding Raphael regression analysis capabilities.

Before performing batch regression analysis, you can set preferences for this operation in the Regression page of the User Preferences notebook. It is highly recommended that the location of the default models and the user-defined equa-tions be specified. Refer to Chapter 5, “Regression Page,” p. 5-6 for additional details on the Regression page of the User Preferences notebook.

Raphael performs fully automatic batch regression for one or more selected struc-tures.

1. Set appropriate user preferences in the Regression page of the User Preferences notebook.

2. Select the desired structures in the Create/Inspect Parasitics Database win-dow (Figure 6-4, p. 6-9).

3. Click the 2. Run Regression button.

4. To select more than one structure, click-drag-release with the mouse, dragging over the desired structures while holding the mouse button down.

5. To change the set of selected structures, press and hold the CONTROL key, then click the mouse button on the desired structures.

Information Output During Batch Regression

Regression analysis will not rerun if it has already been run for the selected struc-tures. For example, regression analysis has already been performed for all struc-tures in the sram database (supplied with Raphael). If you select the last structure in the first row and then click the 2. Run Regression button, the messages shown in Figure 7-5 appear in the UNIX window from which you started Raphael.

The first line of output tells you which structure is being processed. In this case, the structure is shown in Figure 7-1, p. 7-3.

You can rerun regression analysis by clicking the Force Regression using default models button in the Regression page of the User Preferences note-book. Refer to Chapter 5 for further details.

RA 2006.03 7-9

Draft 2/6/06

Batch Regression Analysis Raphael Tutorial

Targets The remaining paragraphs in Figure 7-5 summarize the regression results for each of the targets in the selected structure. As shown in Figure 7-4, p. 7-8, structures of this generic type (array above ground plane) have three targets (C total, C coupling, and C bottom gp). Different generic structures have different targets. Generic structures are explained in Chapter 6.

Models andModel Markers

In Figure 7-2, p. 7-4, there are numerous models to use for regression analysis. When you run a regression analysis manually, direct Raphael to use a specific model by clicking the model you want. When you run batch regression, Raphael checks for model markers to link each model to each target

• Each target has a recommended default model. If no model marker informa-tion is found, the default model is used. This is typical when a parasitics data-base is being created. For example, in Figure 7-5, p. 7-10, the third line of output is:

Looking for default model results (Mono decreasing)...

This line tells you that no model marker information was found; the program checks to see if regression analysis has already been performed by using the default model for this target (in this case, the Mono decreasing model).

• If Raphael locates model marker information for the model to use for a partic-ular target, the program seeks the regression analysis results for that model.

In either case, if Raphael finds the regression results for the model, the regression is not rerun. If the regression results are not found, Raphael automatically runs regression analysis. However, regression analysis can be forcibly performed by choosing Force Regression Analysis using default models in the regression page of the User Preferences notebook. Refer to Chapter 5 for further details.

Processing actual structure: MET1,above,substrate Processing target: C total Looking for last-run model results (Mono decreasing)... RMS error = 0.51 % Skipping C_total (already run) Processing target: C coupling Looking for last-run model results (Coupling)... RMS error = 0.41 % Skipping C_coupling (already run) Processing target: C bottom gp Looking for last-run model results (Mono increasing)... RMS error = 0.18 % Skipping C_bottom_gp (already run)

Figure 7-5 Raphael output after clicking the Run Regression button

7-10 RA 2006.03

Draft 2/6/06

Raphael Tutorial User-Defined Equations

6.Utiilities

Man

ual D

B

Marking a Model A model is automatically marked when you run regression analysis manually by clicking the Run… button in the Regression Analysis window.

A model can also be marked by hand, without actually running the regression analysis:

1. Select a target in the Regression Analysis window.

2. Select the desired model.

3. Execute File➔Mark this model for batch regression.

The model you marked is used in subsequent batch regression analyses performed on the selected structure and target.

To determine if a model has been marked for use with a target:

1. Click to select a target in the Regression Analysis window

2. Execute File➔Query: Which model is marked? The status line displays (for example):

“Mono decreasing” (marked by hand) will be used for thistarget when running batch regression.

User-Defined EquationsSo far, this chapter has referred to various equations defined by Raphael as described in Chapter B. Such equations cannot be modified.

Raphael also allows you to define your own equations and use them for regression analysis, instead of using the equations defined by Raphael. User-defined equa-tions can include a wide variety of mathematical functions, including sin, cos, exp, log, and so on. All parts of the Regression Analysis window work in the same way for user-defined equations as for Raphael-defined equations.

You may load the user-defined equations from any convenient directory by speci-fying the entire path of the directory in the Location of user-defined equations panel in the Regression page of the User Preferences notebook. Refer to Chap-ter 5, “Regression Page,” p. 5-6.

Applying Equations

To apply user-defined equations:

1. Change to the Regression Analysis window.

2. Select a model with a name such as User defined Ia or User defined IIb.

3. Type the desired equation (or edit an existing equation) in the Equation for selected model: text field.

RA 2006.03 7-11

Draft 2/6/06

User-Defined Equations Raphael Tutorial

4. Click the Run… button.

The new equation is used in the regression analysis and is automatically saved to disk.

The remainder of this section provides additional details concerning user-defined equations.

One-Array vs. Two-Array

There are two classes of generic structures: those with a single array of conduc-tors, and those with two arrays of conductors. This distinction is important for regression analysis.

The one-array structures are:

• Array of traces above a ground plane

• Array of traces between two ground planes

• Coincident edge above a ground plane

• Coincident edge between two ground planes

• Oversize structure between two ground planes

The two-array structures are:

• Parallel arrays of traces above a ground plane

• Parallel arrays of traces between two ground planes

• Different layers above a ground plane

• Different layers between two ground planes

• Array crossover above a ground plane

• Array crossover between two ground planes

One-ArrayEquations

For one-array structures, four user-defined equations are available. These equa-tions use s and w as independent variables (see “Variables,” p. 7-13). The equa-tions appear in the Select a Model list and are named:

• User defined Ia

• User defined Ib

• User defined Ic

• User defined Id

Two-ArrayEquations

For two-array structures, eight user-defined equations are available except for the different layers generic structures. (User-defined equations are not currently sup-ported for the different layers of generic structures.) The eight user-defined equa-tions use st, wt, sb, and wb as independent variables (see “Variables,” p. 7-13).

7-12 RA 2006.03

Draft 2/6/06

Raphael Tutorial User-Defined Equations

6.Utiilities

Man

ual D

B

The equations appear in the Select a Model list and are named:

• User defined IIa

• User defined IIb

• User defined IIc

• User defined IIh

Math Functions Most math functions in the C programming language <math.h> library are sup-ported, including:

• acos, asin, atan, cos, cosh, sin, sinh, tan, tanh, exp, erf, erfc, j0, j1, y0, y1, gamma, abs, log, log10, and sqrt

Additionally, the functions min(a, b, c, …) and max(a, b, c, …) are available.

Operators Acceptable operators are +, -, *, /, and ^. The ^ operator is used for exponentia-tion, rather than **. The ** operator is not allowed.

Parsing • White space is ignored.

• Parentheses ( ) may be used.

• A maximum of 1024 characters is allowed in a user-defined equation.

Saving to a File User-defined equations are automatically saved to disk when you click the Run… button in the Regression Analysis window. If you want to force a save to disk without running, execute File➔Save equation to file. Raphael automatically determines the appropriate file name and location.

Restoring from aFile

If you begin editing an equation, but change your mind and wish to restore the unedited equation, you can recover by executing File➔Revert equation. This restores the unedited equation (as long as you have not clicked the Run… button or executed File➔Save equation to file). File➔Revert equation reads the last- stored version of the equation from disk.

Limitations

User-defined equations provide substantial power and flexibility; however, there are a few constraints.

Variables Variables are the independent variables in a Raphael regression equation.

• For a one-array structure, the variable names are limited to s and w (spacing of traces, and width of traces, respectively).

RA 2006.03 7-13

Draft 2/6/06

User-Defined Equations Raphael Tutorial

Note:For the coincident edge above ground plane and coincident edge between ground planes structures, the top array width (w) and the spac-ing (s) are the variables available.

• For a two-array structure, the variable names are limited to:

• No other variable names are permitted.

• By convention, variable names are lowercase.

See “One-Array vs. Two-Array,” p. 7-12 for background.

Parameters Parameters are the coefficients in a Raphael regression equation. When you select a model, the list of acceptable parameter names appears in the Parameter column in the Regression Analysis window.

• For a one-array structure, the parameter names are limited to A, AP, B, BP, C, CP, D, DP, E, F, E11, E11P, E12, E21, E21P, E22, L1, L1P, S11, S11P, and S12.

• For a two-array structure, the parameter names are limited to A, A1, A2, A3, A4, B, B1, B2, B3, B4, C, C1, C2, C3, C4, C5, D, D1, D2, D3, D4, D5, E, E1, E2, E3, E4, F, F1, F2, F3, F4, G, G1, G2, G3, and G4.

• No other parameter names are permitted.

• By convention, parameter names are uppercase.

See “One-Array vs. Two-Array,” p. 7-12 for background.

Shared Approach There is only one copy of each of the user-defined equations. For example, if one user changes the equation for User defined IIc, all Raphael users at that installation can see the new equation.

If there are multiple Raphael users, a coordinated approach may be necessary: for example, one person only uses User defined IIa-d, and a second person only uses User defined IIe-h.

Otherwise, you may choose to load the user-defined equations from different directories, as set by the Regression page of the User Preferences notebook Refer to Chapter 5 for details.

st spacing of traces in the top array

wt width of traces in the top array

sb spacing in the bottom array

wb width in the bottom array

7-14 RA 2006.03

Draft 2/6/06


6.Utiilities

Man

ual D

B

Menu BarThe menu bar at the top of the Regression Analysis window contains a single menu: File.

• Execute File➔Mark this model for batch regression to mark a model for use with the selected target. See “Marking a Model,” p. 7-11 for details.

• Execute File➔Query: Which model is marked? to determine if a model has been marked for use with the selected target. See “Marking a Model,” p. 7-11 for details.

• Execute File➔Save equation to file to save the user-defined equation to disk. See “Saving to a File,” p. 7-13 for details.

• Execute File➔Revert equation to restore the user-defined equation from disk. See “Restoring from a File,” p. 7-13 for details.

Report Generator for Regression ResultsIn this section you learn how to generate a report of the regression analysis for an entire database. The report summarizes the technology characteristics and pro-vides details about the regression analysis performed by Raphael on selected structures. The structures to be included in the report are selected from an existing parasitics database, using the Create/Inspect Parasitics Database window (Figure 6-4, p. 6-9). See Chapter 6 for an overview of that window.

Generating a Report

To generate a report for an existing database, first, click the desired database name in the Raphael Parasitics Database window (Figure 3-1, p. 3-2). Make sure the Create/Inspect Parasitics Database window is open. If it is not open, click the Create Database button in the Raphael Parasitics Database window.

In the Create/Inspect Parasitics Database window, select the structures you want to include in the report.

• To select more than one structure, click-drag-release with the mouse, dragging over the desired structures while holding the mouse button down.

• To change the set of structures selected, press and hold the CONTROL key, then click the mouse button on the desired structures.

• If you do not select any structures, the report will contain only a summary of the technology information shown in the Technology Characteristics win-dow (Figure 4-1, p. 4-2). It will not contain regression results.

To open the Save Report File window, double-click the Report tool icon in the Create/Inspect Parasitics Database (Figure 7-6).

RA 2006.03 7-15

Draft 2/6/06

Report Generator for Regression Results Raphael Tutorial

The report consists of a single ASCII text file to be written to the UNIX file sys-tem. The Save Report File window allows you to specify the name and location of the ASCII text file.

• The default file name is <database>.report.txt, where <database> is the name of the selected database (e.g., sram.report.txt).

• The directory in which you started Raphael is the default directory.

• Use the Save Report File window to save the report to any file name in any valid UNIX directory.

• If you click the Cancel button, the report will not be written.

The reportalso is displayed in the Raphael: Output Terminal window. You can edit and save the contents displayed.

A Sample Report

The following sample report (Figures 7-7 through 7-9) was generated for the sram database. To keep the report short, only a single structure was selected (MET1 above substrate). However, you can select as many structures as you like for inclusion in your reports.

Figure 7-6 Save Report File window

7-16 RA 2006.03

Draft 2/6/06

Raphael Tutorial Report Generator for Regression Results

6.Utiilities

Man

ual D

B

View this report file in your UNIX text file editor.

REPORT FOR "sram"

Thu Jul 24, 1997 4:02:48 PM PDT---------------------------------------------------------------------------

TECHNOLOGY CHARACTERISTICS --------------------------

This technology contains 7 layers:

MET2 (conductor) MET1 (conductor) POLY (conductor) diel_3 (dielectric) diel_2 (dielectric) diel_1 (dielectric) diel_0 (dielectric)

TECHNOLOGY PARAMETERS:

(All distance units in microns)

Conductor Thickness Zmin Zmax --------- --------- ----- ----- MET2 1.2 4.2 5.4 MET1 0.8 1.9 2.7 POLY 0.4 0.5 0.9

Dielectric Thickness Zmin Zmax Dielectric Constant ---------- ---------- ----- ----- ------------------- diel_3 1.6 4.2 5.8 3.9 diel_2 2.3 1.9 4.2 3.9 diel_1 1.4 0.5 1.9 3.9 diel_0 0.5 0 0.5 3.9

DESIGN PARAMETERS:

(width and spacing units in microns)

Conductor Variable Min 1 Max 1 Step 1 Min 2 Max 2 Step 2 --------- -------- ----- ----- ------ ----- ----- ------ MET2 width 1.6 1.8 0.1 0 0 0 MET2 spacing 2.4 2.8 0.1 0 0 0 MET1 width 0.8 2.6 0.9 0 0 0 MET1 spacing 0.6 2.6 0.2 0 0 0 POLY width 0.8 0.9 0.1 0 0 0 POLY spacing 0.6 2.6 0.2 0 0 0

---------------------------------------------------------------------------

Figure 7-7 First portion of report for sram database, summarizing technology information

RA 2006.03 7-17

Draft 2/6/06

Report Generator for Regression Results Raphael Tutorial

GENERIC REGRESSION DATABASE INFORMATION ---------------------------------------

---------------------------------------------------------------------------

Section 1

Generic structure: Array above ground plane

1.1 Actual structure Name: MET1 above substrate

1.1.1Target Name: C total (in fF/micron)

Equation:

A+AP*w+(B+BP*w)/s+(C+CP*w)/exp(s/E)+(D+DP*w)/exp(s^2/F)

Extracted Parameters:

NameValue

A0.066438AP0.022508B0.071686BP5.8426e-05C-0.059014CP0.019291D0.031948DP-0.0033905E0.94326F1.3593

Equation with Parameters Substituted:0.066438+0.022508*w+(0.071686+5.8426e-05*w)/s+((-0.059014)+0.019291*w)/exp(s/0.94326)+(0.031948+(-0.0033905)*w)/exp(pow(s,2)/1.3593)

RMS error from the regression analysis: 0.51%

---------------------------------------------------------------------------

1.1.2Target Name: C coupling (in fF/micron)

Equation:

A+AP/s+B/(s+w)+C/(s+CP)+D/(s+w+DP)


NameValue

Figure 7-8 Middle portion of report for sram database, summarizing regression analysis results

7-18 RA 2006.03

Draft 2/6/06

Raphael Tutorial Report Generator for Regression Results

6.Utiilities

Man

ual D

B

A0.0051769AP0.02609B-0.002296C0.12388CP1.1158D-0.13104DP2.4249Equation with Parameters Substituted:0.0051769+0.02609/s+(-0.002296)/(s+w)+0.12388/(s+1.1158)+(-0.13104)/(s+w+2.4249)


--------------------------------------------------------------------------------------------------------------------------------------------

1.1.3 Target Name: C bottom gp (in fF/micron)

Equation:

A+AP*w+(E11+E11P*w)/exp(E12/s)+(E21+E21P*w)/exp(E22/s^2)+(L1+L1P*w)*log(s)+(S11+S11P*w)/(1+S12/s)


NameValue

A0.03561AP0.0085963E110.035444E11P0.0087214E120E210.035444E21P0.0072192E220L10.038877L1P0.0025582S11-0.11521S11P-0.011277S120.43082

Equation with Parameters Substituted:0.03561+0.0085963*w+(0.035444+0.0087214*w)/exp(0/s)+(0.035444+0.0072192*w)/exp(0/pow(s,2))+(0.038877+0.0025582*w)*log(s)+((-0.11521)+(-0.011277)*w)/(1+0.43082/s)


---------------------------------------------------------------------------------------------------

Figure 7-9 Final portion of report for sram database, summarizing regression analysis results

RA 2006.03 7-19

Draft 2/6/06

Using a Capacitance Curve Tool Raphael Tutorial

Using a Capacitance Curve ToolThis section describes how to display plots of capacitance versus width and capac-itance versus spacing for a selected actual structure. Structures are selected from an existing parasitics database, using the Create/Inspect ParasiticsDatabase window (Figure 6-4, p. 6-9). See Chapter 6 for a detailed discussion of the window.

Visualizing Results

To select a structure, click it directly in the Create/Inspect Parasitics Database window. To duplicate the results shown in this tutorial, click the MET1 above substrate structure in the first row.

To view a plot of capacitance versus spacing for the selected structure, double-click the Cap vs Space tool. The status line at the bottom of the Create/Inspect Parasitics Database window shows the following text:

Launching “Capacitance vs. Space” tool... (please wait).

The plot opens as shown in Figure 7-11.

If you wait more than 30 to 45 seconds, or if there are error messages in the UNIX window from which you started Raphael, see your UNIX systems administrator or the person who installed Raphael on your system.

To view a plot of capacitance versus width, double-click the Cap vs Width tool to open another plot window. For this example, focus on the plot of capacitance ver-sus spacing (Figure 7-11).

Each data point (+) corresponds to a field solver simulation performed for a par-ticular width/spacing combination. Since this is a graph of capacitance versus spacing, width is the parameter that is varied. This combination results in the fam-ily of three related curves appearing in Figure 7-11.

The three widths for the MET1 traces are 0.8 μm, 1.7 μm, and 2.6 μm. To verify these values, examine the min/max/step values in the Width and Spacing Param-eters panel of the Technology Characteristics window for the sram database (Figure 4-1, p. 4-2). The top curve in the plot corresponds to a MET2 trace width of 2.6 μm.

Figure 7-10 Select this structure in the sram database

7-20 RA 2006.03

Draft 2/6/06

Raphael Tutorial Using a Capacitance Curve Tool

6.Utiilities

Man

ual D

B

The window shown in Figure 7-11 contains three plots:

• Total Capacitance vs. Space

• Coupling Capacitance vs. Space

• Capacitance to Ground vs. Space

To see other plots, click the bottom left icon in the General Tools area of this win-dow, and click or in the Page Tool window.

For precise, structure-specific definitions of terms such as total capacitance and coupling capacitance, see Appendix A in this tutorial.

Using the Visualization Window

The STUDIO Visualize graphics window shown in Figure 7-11 is part of a Synopsys TCAD stand-alone visualization program. Some of the main elements of the STUDIO Visualize window are:

• Multiple plots appear within a single window.

• To see other plots, click the bottom left icon in the General Tools area, then click or in the resulting Page Tool window.

Figure 7-11 Plot of total capacitance vs. spacing

RA 2006.03 7-21

Draft 2/6/06

Using a Capacitance Curve Tool Raphael Tutorial

• To identify the value of the parameter for a particular curve, choose the Select tool (identified by an arrow at the top-left corner of the General Tools area). Double-click in the plotting area to open the Plot Inspector window, where you can specify different symbols or colors for the data sets of each value of the parameter.

• To change the symbols used for data points, or to add lines connecting the data points, or add labels, use the Plot Inspector window.

• You can also save the plot to a PostScript file for inclusion in a report.

The STUDIO Visualize graphics program is fully described in the STUDIO User’s Manual.

7-22 RA 2006.03

Draft 2/6/06

CHAPTER 8

R

7. LP

E To

olss

Dracu

la

LPE Tools Interface: Dracula8

OverviewIn this chapter you learn to generate rule checks for parasitic capacitance coeffi-cients using the syntax of Dracula.

The interface between Raphael and LPE tools provides a fast and consistent way of generating LPE rule decks with accurate interconnect parasitic capacitance coefficients and equations. Currently, the interface also supports Cadence’s Diva and Vampire (see Chapter 9, “LPE Tools Interface: Diva and Vampire”) and Men-tor Graphics’ xCalibre and ICextract (see Chapter 10, “LPE Tools Interface: xCal-ibre and ICextract”).

Note:The interface between Raphael and Dracula has been completely rede-signed since Raphael 4.1. The GRD-Based LPE Interface is no longer available.

To invoke the LPE tools interface:

1. In the Raphael main window, click the Parasitics Database & LPE Tools Interface button to open the Raphael Parasitics Database window (Figure 3-1, p. 3-2).

2. Click the desired database name from the list displayed in the Select a data-base panel. If a database has not been created, see Chapter 3.

3. Click the button labeled LPE Tools Interface. If you are an authorized licensed user of the interface, the LPE Tools Interface window opens (Figure 8-1).

A 2006.03 8-1

Draft 2/6/06

Capacitance Terminology Raphael Tutorial

Capacitance TerminologyThe main capacitance components extracted in the LPE tools interface are described in this section.

• The capacitance between two conductors can be divided into overlap (i.e., area and perimeter) and lateral coupling capacitances. Figure 8-2 illustrates each of these components in more detail.

• Area capacitance is the component between the bottom of a conductor to the top of the conductor stacked below it.

• Perimeter capacitance between two conductors may consist of sidewall up and sidewall down components.

If the top conductor’s edge (Conductor 2) over the bottom conductor (Conductor 1) is used to extract the capacitance, then it is a sidewall down case. If the bottom conductor’s edge below the top conductor is used, then it is a sidewall up case (see Figure 8-2).

The perimeter capacitance value also depends on the spacing between neigh-boring conductors in the same metal level.

• Coincident edge perimeter capacitance is a special case of perimeter capaci-tance, where the edges of the conductors are coincident to each other.

• Lateral coupling capacitance can be divided into same-layer and different-layer coupling components. In Figure 8-2, same-layer lateral coupling capaci-tance is shown as component C, and different-layer lateral coupling as com-ponent D.

Figure 8-1 LPE Tools Interface window

8-2 RA 2006.03

Draft 2/6/06

Raphael Tutorial Using Dracula LPE Interface

7. 7. L

PE

Too

lss

Using Dracula LPE InterfaceThe steps for generating the Dracula rule files for parasitics capacitance coeffi-cients can be broadly outlined as:

1. Selecting target LPE format

2. Changing layer information (optional)

3. Specifying options (optional)

4. Generating the rule file

The following sections discuss each of the steps in detail.

Step 1: Selecting Target LPE Format

To choose the target LPE format to Dracula, select the Dracula item from the 1.LPE Tool Format menu.

Step 2: Changing Layer Information (optional)

When the LPE Tools Interface window (Figure 8-1) opens, the technology infor-mation for conductor layers is displayed in the LPE Layer Information panel of the LPE Tools Interface window. However, the information in this section can be

Figure 8-2 Capacitance terminology used in LPE Tools Interface

Conductor 2

Conductor 1

Ground Plane

C

A

Legend:

A: Area capacitanceB: Perimeter capacitanceC: Same Layer Lateral Coupling capacitanceD: Different Layer Lateral Coupling capacitance

A

B D B

A B

B

RA 2006.03 8-3

Draft 2/6/06

Using Dracula LPE Interface Raphael Tutorial

overridden. For instance, you can reduce the ranges for width and spacing of con-ductors to correspond more closely to the actual layouts. You also can override the layer names by editing directly in the LPE Layer Information panel. You can save the modified information into a file and reload it later using the File menu shown in Figure 8-3.

Note:The modified min and max values cannot be outside the simulation ranges. The LPE Tools Interface window automatically resets out-of-range values to either the minimum or maximum simulation ranges.

Step 3: Specifying the Options (optional)

To help generate more accurate capacitance models, Raphael provides various options for the LPE interface. The default option setting gives accurate capaci-tance coefficients for a wide range of designs. However, more accurate coeffi-cients may be obtained by changing the available options to fit your particular design.

Note:A set of preferences for each database must be set independently.

To change the options, in the LPE Tools Interface window menu bar, execute Options➔Preferences to open the LPE Tools Interface Options window. This window consists of four pages.

However, only the first two pages, the General (Figure 8-5) and Dracula (Figure 8-11) pages, are relevant to the Dracula interface. See “Setting LPE Tools Inter-face Options,” p. 8-5 for a detailed discussion.

Step 4: Generating the Rule File

To generate rule files for parasitic capacitance coefficients for interconnect layers, click the Generate LPE File… button in the LPE Tools Interface window (Figure 8-1). The final rule file is displayed in the Output Terminal window, as shown in Figure 8-4. The rule file can be edited directly in the window. To save the rule file into a file, execute File➔Save File As… in the menu bar of the Output Terminal window.

Figure 8-3 File operations for conductor layer information

8-4 RA 2006.03

Draft 2/6/06

Raphael Tutorial Setting LPE Tools Interface Options

7. 7. L

PE

Too

lss

Setting LPE Tools Interface Options This section teaches you how to set the LPE Tools Interface Options window for Dracula. The General and Dracula pages of the window are discussed in detail.

General Page

The General page, shown in Figure 8-5 of the LPE Tools Interface Options win-dow, presents options for LPE tools. The page is divided into four groups described in the following sections.

Group 1:Perimeter

CoefficientModeling

The first group, Perimeter Coeff. btwn Metal Layers, specifies the model to be used for the perimeter coefficient (overlap capacitance) between two metallayers.

Figure 8-4 Output Terminal window of Dracula interface

RA 2006.03 8-5

Draft 2/6/06

Setting LPE Tools Interface Options Raphael Tutorial

Three different modeling choices are available:

• 2D models: all perimeter coefficients are extracted from 2D structures

• 3D models (from crossover structures): all perimeter coefficients are extracted from 3D crossover structures

• Alternating 2D and 3D models: 2D structures are used for the perimeter coefficient between parallel metal layers. 3D crossover structures are used for metal layers running orthogonally. For this model, any two adjacent metal lay-ers are assumed to run orthogonally. For instance, poly-metal 1, metal 1-metal 2, metal 2-metal 3, and poly-metal 3 run orthogonally, whereas poly-metal 2 and metal 1- metal 3 run in parallel.

Note:The lateral coupling capacitance and the perimeter coefficient between a metal layer to a ground plane (substrate) are always modeled by a 2D structure.

Figure 8-5 General page, LPE Tools Interface Options window

8-6 RA 2006.03

Draft 2/6/06


7. 7. L

PE

Too

lss

Figures 8-6 and 8-7 show the overlap capacitance models using 2D and 3D struc-tures. As shown in these figures, the perimeter coefficient value from the 3D struc-ture is higher than the value from the 2D structure, as expected.

In the following paragraphs, a brief theoretical background on modeling the perimeter coefficient (overlap capacitance) is presented.

Figure 8-6 Overlap capacitance models based on 2D and 3D structures

Figure 8-7 Overlap capacitance models based on 2D and 3D structures using the extractParasitic command

; STRUCTURE: ME2 above ME1; with BULK as a bottom ground plane (C1).

; Cperimeter: arr_cross_above_gp/MET2,MET1,substratePARASITIC CAP[C6] DEV_LAYER ME2 ME1ATTRIBUTE CAP[C6] 0.02302 0.02884


; Csu: arr_btwn_gps/MET2,MET1,substrate; Csd: arr_above_gp/MET2,above,MET1; Cperimeter: weighted average of Csu and Csd

PARASITIC CAP[C6] DEV_LAYER ME2 ME1ATTRIBUTE CAP[C6] 0.02302 0.01956

Based on 3D structure



; Cperimeter: arr_cross_above_gp/MET2,MET1,substratecap( ME1 ME2 0.02302 0.02884 )


; Csu: arr_btwn_gps/MET2,MET1,substrate; Csd: arr_above_gp/MET2,above,MET1; Cperimeter: weighted average of Csu and Csd

cap( ME1 ME2 0.02302 0.01956 )



RA 2006.03 8-7

Draft 2/6/06


Insights onPerimeter

CoefficientModeling

Two overlapping traces between metal layers can run either in parallel or orthogo-nal to each other. When they run in parallel, the perimeter coefficient (overlap capacitance model) should be derived from 2D structures. In orthogonal cases, a more accurate perimeter coefficient (overlap capacitance model) may be extracted from 3D crossover structures. Figure 8-8 shows the overlap and lateral coupling capacitance components with associated structures.

Most LPE tools cannot distinguish the parallel vs. orthogonal overlap of the two conductors during computation of the overlap capacitance. In these tools, the same set of area and perimeter capacitance components is applied to both cross-over and parallel overlap cases. This is one of the major sources of errors associ-ated with the overlap capacitance calculated by LPE tools.

For typical layouts, which contain both crossover and parallel overlaps, the over-lap capacitance calculated based solely on 2D structures may underestimate the actual capacitance. In contrast, the overlap capacitance based on only 3D struc-tures may overestimate the capacitance. Therefore, the proper selection of struc-tures (2D or 3D) is crucial for accurate characterization of the overlap capacitance.

Group 2:Adjacent Layer

Specification

The second group, Maximum No. of Adjacent Layers to be Extracted, specifies the maximum number of adjacent layers for overlap and lateral coupling capaci-tances.

OverlapCapacitance

The default number of adjacent layers for the overlap capacitance is set to 10. For processes with less than 12 metal layers, this default value includes the overlap capacitances for all combinations of metal layers.

Figure 8-8 Overlap and lateral coupling capacitance components with associated structures

Ground Plane

C

Legend:A: Overlap capacitance based on 2D structuresB: Overlap capacitance based on 3D structures (crossover)

B B

C A A

C: Lateral coupling capacitance (based on 2D structures only)

A A

8-8 RA 2006.03

Draft 2/6/06


7. 7. L

PE

Too

lss

If the default value is set to 1, only the overlap capacitance model between neigh-boring layers is included. For instance, the overlap capacitance between metal 1 to metal 2 is generated, but the overlap capacitance model between poly to metal 2 is not generated.

If you specify the value as 0, no overlap capacitance model between metal layers is included in the output rule file.

Note:The overlap capacitance between a metal layer to substrate (ground plane) is always generated regardless of the specified value.

Lateral CouplingCapacitance

For lateral coupling, the default number of adjacent layers is set to 1, which speci-fies the inclusion of same-layer lateral coupling and lateral coupling between the nearest neighboring conductors only. For instance, metal 1 to metal 1, metal 1 to metal 2, and metal 1 to poly lateral coupling capacitance models are generated, but the metal 1 to metal 3 lateral coupling capacitance model is not generated.

By specifying the number of adjacent layers as 0, only the same-layer lateral cou-pling is considered.

CAUTIONDo not specify the number of adjacent layers to be more than 1 for lateral coupling. Including non-nearest layers may result in significant overestima-tion of lateral coupling capacitance. See “Insights on Lateral Coupling Ca-pacitance Modeling,” p. 8-10 for a theoretical discussion.

Group 3: LateralCouplingDistance

Specification

The third group, Maximum Lateral Distance for Lateral Coupling, allows you to specify the maximum distance to consider for the lateral coupling. Refer to “Insights on Lateral Coupling Capacitance Modeling,” p. 8-10 for a theoretical discussion.

Two different values can be specified for same-layer and different-layer lateral couplings. Values are specified as a multiplication factor of minimum spacing. In the case of different-layer coupling, it multiplies by the minimum spacing of the bottom layer. When the final distance resulting from the minimum spacing multi-plied by the factor is larger than the maximum spacing, the maximum spacing is used instead of the distance obtained from the specified factor.

Since the distance factor for different-layer coupling is more susceptible to the third-body effect, it should be smaller than the factor for same-layer coupling.

Note:If you need to specify the maximum distance arbitrary, change the maxi-mum spacings in the maximum distance (Figure 8-1) to the distances you desire first. Then, set the factor value large enough so that the

RA 2006.03 8-9

Draft 2/6/06


resulting distances (factor times the minimum spacings) are larger than the maximum spacings.

Insights on LateralCoupling

CapacitanceModeling

Most LPE tools compute the lateral coupling capacitance based on two-body interaction only. They compute the lateral coupling capacitance between two traces without considering neighboring third-body traces that are not part of the capacitance terminals (nodes). By neglecting the possible presence of third-body traces, the charge sharing effect of the third-body traces is ignored and the cou-pling capacitance is, in turn, significantly overestimated. This is one of the major reasons why the capacitance values obtained from LPE tools are often higher than true values.

Figure 8-9 illustrates why the lateral coupling capacitance model for nonadjacent layers should be excluded. Figure 8-10 illustrates why the maximum distance for lateral coupling capacitance should be limited.

Figure 8-9 Coupling capacitance beyond the adjacent layer can be significantly overestimated

Figure 8-10 Coupling capacitance beyond the nearest neighboring conductors can be overestimated

Conductor 1

Conductor 2

CapacitanceTerminal

Conductors

Third-bodyConductors

Conductor 1 Conductor 2

CapacitanceTerminal

Conductors


8-10 RA 2006.03

Draft 2/6/06


7. 7. L

PE

Too

lss

Group 4: OutputUnit

Specification

The last group of the General page (Figure 8-5) of the LPE Tools Interface Options window (Figure 8-1) allows you to specify the output unit of capaci-tance. By default, the unit of femto-farads, fF, is used for the output.

Dracula Page

In the Dracula page (Figure 8-11) of the LPE Tools Interface Options window, you can specify options related to Dracula syntax. This page consists of three groups, which are explained in the following sections.

Group 1: Non-Interacting Metal

Modeling

The first group, Non-Interacting Metal Layers, allows you to specify either effec-tive top or bottom ground planes for modeling non-interacting (non-terminal) metal layers. By default, non-interacting metal layers are ignored during capaci-tance model generation. For example, for the capacitance model between Metal 1 and Metal 2, Poly or any other metal layers are not considered during the model generation.

Figure 8-12 (a) shows the default structure used to model the overlap capacitance between Metal 1 and Metal 2 in a three-metal-layer technology. Figure 8-12 (b)

Figure 8-11 Dracula page, LPE Tools Interface Options window

RA 2006.03 8-11

Draft 2/6/06


shows additional structures also used for modeling the same overlap capacitance by treating all possible neighboring metal layers as effective ground planes.

By enabling the Modeled as effective top/bottom ground planes button, the capacitance models generated by the structures shown in Figure 8-12 (b) are also included in rule decks. To include all of the capacitance models generated by con-sidering all possible neighboring metal layers as effective ground planes (Figure 8-12 (b)), select the All layers button.

To replace the default model (Figure 8-12 (a)) with the capacitance model gener-ated by considering only the nearest neighboring conductor(s) as the effective ground plane(s), select the Adjacent layers only button. In the above example, instead of using the structure shown in Figure 8-12 (a), the structure shown at the bottom of Figure 8-12 (b) is used to generate the capacitance model between Metal 1 and Metal 2. The capacitance model using this option results in the least capacitance value.

Figure 8-12 (a) Default capacitance model derived using the structure of every two interacting layers (Metal 1 and 2) and substrate (b) Additional structures and models used when Modeled as effective top/bottom ground planes option is selected

Ground Plane (always substrate)

Metal 1Metal 2

(a) Default Structure

Ground Plane (Poly)

Metal 1

Metal 2

Ground Plane (substrate)

Metal 1

Metal 2

(b) Additional Structures

Ground Plane (Metal 3)

Ground Plane (Poly)

Metal 1

Metal 2


+

8-12 RA 2006.03

Draft 2/6/06


7. 7. L

PE

Too

lss

CAUTIONIf you selected the All layers button, you must select (i.e., cut and paste) the capacitance model that best fits your design. Dracula syntax allows only one capacitance model for the overlap capacitance between two given metal lay-ers.

Figures 8-13 and 8-14 list the overlap capacitance outputs of Figure 8-12 using the Modeled as effective top/bottom ground planes button and selecting the All layers option.

Figure 8-13 Overlap capacitance models for Figure 8-12

; STRUCTURE: Metal_2 above Metal_1; with BULK as a bottom ground plane (C1); Cperimeter: arr_cross_above_gp/Metal_2,Metal_1,substratePARASITIC CAP[C5] DEV_LAYER Metal_2 Metal_1ATTRIBUTE CAP[C5] 0.02302 0.02888

; STRUCTURE: Metal_2 above Metal_1; with Poly as a bottom ground plane (C2); Cperimeter: arr_cross_above_gp/Metal_2,Metal_1,PolyPARASITIC CAP[C22] DEV_LAYER Metal_2 Metal_1ATTRIBUTE CAP[C22] 0.02302 0.02856

; STRUCTURE: Metal_2 above Metal_1; with BULK as a bottom ground plane; and Metal_3 as a top ground plane (C3); Cperimeter: arr_cross_btwn_gps/Metal_3,Metal_2,Metal_1,

substratePARASITIC CAP[C34] DEV_LAYER Metal_2 Metal_1ATTRIBUTE CAP[C34] 0.02302 0.02642

; STRUCTURE: Metal_2 above Metal_1; with Poly as a bottom ground plane; and Metal_3 as a top ground plane (C3); Cperimeter: arr_cross_btwn_gps/Metal_3,Metal_2,Metal_1,PolyPARASITIC CAP[C35] DEV_LAYER Metal_2 Metal_1ATTRIBUTE CAP[C35] 0.02302 0.02611

Default model

Additionalmodels

RA 2006.03 8-13

Draft 2/6/06


Group 2:Perimeter

CoefficientSetting

In the second group, Perimeter Coefficient, of the Dracula page (Figure 8-11), there are three different formats for perimeter coefficients. These formats are described in the following sections.

Constant ValueFormat

Selecting the Constant value button specifies that the perimeter capacitance is a constant value computed at the average lateral spacing. This is the simplest form of the perimeter capacitance model. Figures 8-15 and 8-16 show the typical out-puts of the overlap capacitance with the Constant value option.

Note:The lateral coupling capacitance is always a function of spacing.

Figure 8-14 Overlap capacitance models for Figure 8-12 using the extractParasitic command

; STRUCTURE: Metal_2 above Metal_1; with BULK as a bottom ground plane (C1); Cperimeter: arr_cross_above_gp/Metal_2,Metal_1,substratecap( Metal_1 Metal_2 0.02302 0.02888 )

; STRUCTURE: Metal_2 above Metal_1; with Poly as a bottom ground plane (C2); Cperimeter: arr_cross_above_gp/Metal_2,Metal_1,Polycap( Metal_1 Metal_2 0.02302 0.02856 )

; STRUCTURE: Metal_2 above Metal_1; with BULK as a bottom ground plane; and Metal_3 as a top ground plane (C3); Cperimeter: arr_cross_btwn_gps/Metal_3,Metal_2,Metal_1,

substratecap( Metal_1 Metal_2 0.02302 0.02642 )

; STRUCTURE: Metal_2 above Metal_1; with Poly as a bottom ground plane; and Metal_3 as a top ground plane (C3); Cperimeter: arr_cross_btwn_gps/Metal_3,Metal_2,Metal_1,Polycap( Metal_1 Metal_2 0.02302 0.02611 )

Default model

Additionalmodels

8-14 RA 2006.03

Draft 2/6/06


7. 7. L

PE

Too

lss

Sidewall up anddown Format

Choosing the Split into side-wall up & down components button sets the perim-eter capacitance between two metal layers to be split into sidewall up/down and coincident edge components (see Figure 8-17). The coincident edge and sidewall up/down capacitance models are written as a constant value (i.e., independent of the lateral spacing).

This format applies to the perimeter capacitance between two metal layers only. The perimeter coefficient between a metal layer to the ground is written as a func-tion of lateral conductor spacing. See Conductor 1 to the ground plane in Figure 8-17.

If this option is not selected, the perimeter capacitance model between two metal layers is calculated using the weighted average of the sidewall up and down com-ponents.

Figure 8-18 shows a typical output for the overlap capacitance using the option Split into sidewall up & down components. This option is only available for the extractParasitic syntax of Dracula, which is available for Dracula version 4.5 or later.

Figure 8-15 Overlap capacitance model with Constant value option

Figure 8-16 Overlap capacitance model with Constant value option using the extractParasitic command


; Cperimeter: arr_cross_above_gp/MET2,MET1,substrate

PARASITIC CAP[C6] DEV_LAYER ME2 ME1ATTRIBUTE CAP[C6] 0.02302 0.02884

Area coefficient Perimeter coefficient

Describes the layer configuration

Lists the generic structure used to generate the perimetercapacitance model



cap( ME1 ME2 0.02302 0.02884 )

Area coefficient Perimeter coefficient

RA 2006.03 8-15

Draft 2/6/06


Function of lateralspacing Format

Selecting the As a function of lateral spacing button outputs the perimeter capacitance as a function of lateral conductor spacing. The lateral spacing can be between either the top or the bottom conductors. Figures 8-19 and 8-20 are typical outputs for overlap capacitance with the As a function of lateral spacing option.


Figure 8-18 Overlap capacitance model using Dracula 4.5 syntax with Split into sidewall up & down components option

Conductor 2

Conductor 1

Sidewall down

Sidewall up Coincident edge


; Ccoed: coin_edge_above_gp/MET2,MET1,substrate; Csu, Csd: arr_cross_above_gp/MET2,MET1,substrate

cap( ME2 ME1 0.02302 0.0104 0.02249 0.03519 )

Area coeff.

Lists the generic structures used to generate the coincident,sidewall up and down capacitance models

Coincident edge coeff.Sidewall up coeff.

Sidewall down coeff.

8-16 RA 2006.03

Draft 2/6/06


7. 7. L

PE

Too

lss

Figure 8-19 Overlap capacitance model with As a function of lateral spacing option

Figure 8-20 Overlap capacitance model with As a function of lateral spacing option using the extractParasitic command



PARASITIC CAP[C6] DEV_LAYER ME2 ME1ATTRIBUTE CAP[C6] 0.02302 0.03002 2.4 0.02811ATTRIBUTE CAP[C6] 0.02302 0.03002 2.45 0.02817ATTRIBUTE CAP[C6] 0.02302 0.03002 2.5 0.02823ATTRIBUTE CAP[C6] 0.02302 0.03002 2.55 0.02853ATTRIBUTE CAP[C6] 0.02302 0.03002 2.6 0.02884ATTRIBUTE CAP[C6] 0.02302 0.03002 2.65 0.02914ATTRIBUTE CAP[C6] 0.02302 0.03002 2.7 0.02944ATTRIBUTE CAP[C6] 0.02302 0.03002 2.75 0.02973ATTRIBUTE CAP[C6] 0.02302 0.03002 2.8 0.03002

Area coeff.Max. perimeter coeff.

Lateral spacingPerimeter coeff.


; cap(ME2 ME1 0.02302 0.0104 0.02249 0.03519)


cap(ME1 ME2 0.02302 0.03002 lateral) ME2

( 2.4 0.02811 ) ( 2.45 0.02817 )( 2.5 0.02823 )( 2.55 0.02853 )( 2.6 0.02884 ) ( 2.65 0.02914 )( 2.7 0.02944 ) ( 2.75 0.02944 )( 2.8 0.03002 )

Area coeff.

Max. perimeter coeff.

Coincident edge, sidewall up and down models are also listed here.

Function of ME2

Lateral spacing Perimeter coefficient

lateral spacing

RA 2006.03 8-17

Draft 2/6/06


Group 3: OutputFormat

The last group of the Dracula page (Figure 8-11) allows you to specify additional options.

Additional DataPoints

The text box labeled Number of additional pts between simulations lets you enter the number of additional (linearly-interpolated) points between the simu-lated points. This option is useful when the number of simulation points is small. By default, one point is added between every two simulation points.

extractParasiticCommand

By selecting the Use “extractParasitic” command button, the capacitance model is written using the extractParasitic command, which is only available for Dracula version 4.5 or later. The Split into side-wall up & down components button is enabled only if this option is selected. See “Sidewall up and down Format,” p. 8-15.

Button Operations

There are four buttons available in the LPE Interface Options window, Figure 8-5 or Figure 8-11:

• Apply: apply and save changes

• OK: same as Apply and close window

• Defaults: reset all options to default values

• Cancel: discard changes and close window

Exporting and Importing LPE Interface Options

You can save the current LPE options to file and load the saved file using the File menu (Figure 8-21) in the LPE Tools Interface Options window (Figure 8-5).

Figure 8-21 File menu in LPE Tools Interface Options window

8-18 RA 2006.03

Draft 2/6/06

Raphael Tutorial SRAM Example

R

7. 7. L

PE

Too

lss

SRAM ExampleIn this section, an SRAM example is used to show the Dracula results with the capacitance models generated by the LPE tools interface. Figure 8-22 shows the layout view of this SRAM cell and Figure 8-23 shows the full-3D view.

Figure 8-22 SRAM cell layout

Figure 8-23 3D view of SRAM cell

A 2006.03 8-19

Draft 2/6/06

SRAM Example Raphael Tutorial

The result, obtained by a rigorous 3D field solver (Raphael-NES), is used to ver-ify the accuracy of data obtained from the LPE tool. The LPE layer information is the same as shown in Figure 8-1. The LPE interface options used are shown in Figures 8-24 and 8-25.

The comparison is shown in Figure 8-26. Another simulation also is performed using the same setting, except that only 2D structures are used to model the perim-eter coefficients. (See “Group 1: Perimeter Coefficient Modeling,” p. 8-5). The results are also shown in Figure 8-26.

The simulation result of a 2x2 SRAM array (Figure 8-27) also is performed using the original options. The results are shown in Figure 8-28.

Figure 8-24 General page setting used for the SRAM example

8-20 RA 2006.03

Draft 2/6/06


R

7. 7. L

PE

Too

lss

Figure 8-26 Comparison of Dracula and full-3D Raphael-NES capacitances (in fF) for a single SRAM cell. The Dracula 3D (and 2D) results were obtained by using 3D crossover (and 2D parallel) structures to generate the perimeter coefficients

Figure 8-25 Dracula page setting used for the SRAM example

NODE Raphael-NES Dracula (3D) Dracula (2D)

BIT 3.17 4.16 (+31%) 3.63 (+14%)

NOT_BIT 3.20 4.17 (+30%) 3.63 (+14%)

VDD 2.59 2.56 (-1%) 2.42 (-7%)

GND 2.92 3.48 (+19%) 3.15 (+8%)

S_M1_1 5.58 6.95 (+25%) 6.45 (+16%)

S_M1_0 5.50 6.99 (+27%) 6.50 (+18%)

WORD 2.09 2.39 (+14%) 2.32 (+11%)

A 2006.03 8-21

Draft 2/6/06


Figure 8-28 Comparison of Dracula and full-3D (Raphael-NES) capacitances (in fF) for a 2x2 SRAM array. The 3D crossover structure was used to extract the perimeter coefficients

Figure 8-27 Taurus Layout view of a 2 x 2 SRAM array

Raphael-NES

Dracula (3D)

BIT 7.04 9.09 (+21%)

NOT_BIT 6.99 9.11 (+30%)

VDD 5.10 4.99 (-2%)

GND 5.40 6.86 (+27%)

S_M1_1 5.62 7.01 (+25%)

S_M1_0 5.62 6.97 (+24%)

WORD 4.01 4.71 (+17%)

8-22 RA 2006.03

Draft 2/6/06

CHAPTER 9

R

8. LP

E To

ols

Diva-V

amp

ire

LPE Tools Interface: Diva and Vampire9

OverviewThe interface between Raphael and LPE tools provides a fast and consistent way of generating LPE rule decks with accurate interconnect parasitic capacitance coefficients and equations. Currently, the interface also supports Cadence’s Diva and Vampire (see Chapter 8, “LPE Tools Interface: Dracula”) and Mentor Graph-ics’ xCalibre and ICextract (see Chapter 10, “LPE Tools Interface: xCalibre and ICextract”).

To invoke the LPE tools interface:


2. Click the desired database name from the list displayed in the Select a data-base panel. If a database has not been created, see Chapter 3.

3. Click the button labeled LPE Tools Interface. If you are an authorized licensed user of the interface, the LPE Tools Interface window opens (Figure 9-1).

A 2006.03 9-1

Draft 2/6/06



• The capacitance between two conductors can be divided into the overlap (i.e., area and perimeter) and lateral coupling capacitances. Figure 9-2 illustrates each of these components in more detail.


• Perimeter capacitance between two conductors may consist of sidewall up and sidewall down components.If the top conductor’s edge (Conductor 2 in Figure 9-2) over the bottom con-ductor (Conductor 1 in Figure 9-2) is used to extract the capacitance, then it is a sidewall down case. If the bottom conductor’s edge below the top conductor is used, then it is a sidewall up case.The perimeter capacitance value also depends on the spacing between neigh-boring conductors in the same metal level.


• Lateral coupling capacitance can be divided into same-layer and different-layer coupling components. In Figure 9-2, the same-layer lateral coupling capacitance is shown as component C, and the different-layer lateral coupling is shown as component D.


9-2 RA 2006.03

Draft 2/6/06

Raphael Tutorial Diva and Vampire LPE Interface

R

8. LP

E To

ols

Diva-V

amp

ire

Diva and Vampire LPE InterfaceThe steps involved in generating the rule files for parasitic capacitance coeffi-cients in the syntax of Diva and Vampire can be broadly outlined as:

1. Selecting the target LPE format to Diva and Vampire.

2. Changing layer information (optional).

3. Specifying options (optional).

4. Generating the rule file.

The following paragraphs outline each of the above steps in more detail.

Step 1: Selecting the Target LPE Format

To choose the target LPE format to Diva or Vampire, select the Diva & Vampire item from the 1.LPE Tool Format menu.

Step 2: Changing the Layer Information (optional)

As soon as the LPE Tools Interface window (Figure 9-1) is opened, the technol-ogy information related with conductor layers is displayed in the LPE Layer Information panel of the LPE Tools Interface window. All the information in this


Conductor 2

Conductor 1

Ground Plane

C

A

Legend:


A

B D B

A B

B

A 2006.03 9-3

Draft 2/6/06

Diva and Vampire LPE Interface Raphael Tutorial

section can be overridden. For instance, you can reduce the ranges for width and spacing of conductors so that they correspond more closely to the actual layouts. The layer names can also be overridden by editing directly in the LPE Layer Information panel. The modified information can be saved into a file and reloaded later using the File menu shown in Figure 9-3.

Note:The modified min and max values cannot be outside the simulation ranges. The LPE Tools Interface window automatically resets out-of-range values to either the minimum or maximum of simulation ranges.


Raphael provides various options for the LPE interface to help generate more accurate capacitance models. The default option setting has been chosen to give accurate capacitance coefficients for a wide range of designs. However, more accurate coefficients may be obtained by changing the available options to fit your particular design.

Note:Each database has a set of preferences which must be set independently.

To change the options, in the LPE Tools Interface window menu bar, execute Options➔Preferences. This opens the LPE Tools Interface Options window. This window consists of four pages, but only two pages, the General (Figure 9-5) and Diva & Vampire (Figure 9-10) pages, are relevant to the Dracula interface. See “Setting LPE Tools Interface Options,” p. 9-5 for a detailed discussion.


To generate the rule files for parasitic capacitance coefficient for interconnect lay-ers, click the Generate LPE File… button in the LPE Tools Interface window (Figure 9-1). The final rule file is displayed in the Output Terminal window as shown in Figure 9-4. The rule file can be edited directly in the window. To save the rule file into a file, execute File➔Save File As… in the menu bar of the Output Terminal window.


9-4 RA 2006.03

Draft 2/6/06


R

8. LP

E To

ols

Diva-V

amp

ire

Setting LPE Tools Interface OptionsThis section teaches you how to set the LPE Tools Interface Options window for Dracula. The General and Diva & Vampire pages of the option window are dis-cussed in detail.

General Page

The General page, shown in Figure 9-5 of the LPE Tools Interface Options window, presents the options for LPE tools. The page is divided into four groups, which are described in the following sections.

Group 1:Perimeter

CoefficientModeling

The first group, Perimeter Coeff. btwn Metal Layers, specifies the model to be used for the perimeter coefficient (overlap capacitance) between two metal layers.

Figure 9-4 Output Terminal window of Diva & Vampire interface

A 2006.03 9-5

Draft 2/6/06





• Alternating 2D and 3D models: 2D structures are used for the perimeter coefficient between parallel metal layers. 3D crossover structures are used for the metal layers running orthogonally. For this model, any two adjacent metal layers are assumed to run orthogonally. For instance, poly-metal 1, metal 1-metal 2, metal 2-metal 3, and poly-metal 3 run orthogonally, whereas poly-metal 2 and metal 1- metal 3 run in parallel.


Figure 9-5 General page of LPE Tools Interface Options window.

9-6 RA 2006.03

Draft 2/6/06


R

8. LP

E To

ols

Diva-V

amp

ire

Figure 9-6 shows the overlap capacitance models using 2D and 3D structures. As shown in this figure, the perimeter coefficient value from the 3D structure is higher than the value from the 2D structure, as expected.

The following paragraphs present a theoretical background on modeling the perimeter coefficient (overlap capacitance).


CoefficientModeling




Figure 9-6 Overlap capacitance models based on 2D and 3D structures using Diva & Vampire syntax

; STRUCTURE: ME2 above ME1; with BULK as a bottom ground plane (C1)

; Ccoed: coin_edge_above_gp/MET2,MET1,substrate; Csd, Csu: arr_cross_above_gp/MET2,MET1,cond_1

cap( ME1 ME2 0.02302 0.02249 0.03519 0.0104 )

STRUCTURE: ME2 above ME1; with BULK as a bottom ground plane (C1)

; Ccoed: coin_edge_above_gp/MET2,MET1,substrate; Csd: arr_above_gp/MET2,above,MET1; Csu: arr_btwn_gps/MET2,MET1,substrate

cap( ME1 ME2 0.02302 0.01525 0.02386 0.0104 )



A 2006.03 9-7

Draft 2/6/06



Specification

The second group, Maximum No. of Adjacent Layers to be Extracted, specifies the maximum number of adjacent layers for the overlap and lateral coupling capacitances.

OverlapCapacitance Case

Set the default number of adjacent layers for the overlap capacitance to 10. For processes with less than 12 metal layers, this default value includes the overlap capacitances for all combinations of metal layers.

If you set this value to 1, only the overlap capacitance model between neighboring layers is included. For instance, the overlap capacitance between metal 1 to metal 2 is generated, but the overlap capacitance model between poly to metal 2 is not generated.

If you set the value to 0, no overlap capacitance model between metal layers is included in the output rule file.


Lateral CouplingCapacitance Case

For lateral coupling, the default number of adjacent layers is set to 1, which includes the same-layer lateral coupling and lateral coupling between the nearest neighboring conductors only. For instance, metal 1 to metal 1, metal 1 to metal 2, and metal 1 to poly lateral coupling capacitance models are generated, but the metal 1 to metal 3 lateral coupling capacitance model is not generated.



Ground Plane

C


B B

C A A


A A

9-8 RA 2006.03

Draft 2/6/06


R

8. LP

E To

ols

Diva-V

amp

ire

CAUTIONDo not specify the number of adjacent layers to be more than 1 for lateral coupling, including non-nearest layers, which may result in significant overes-timation of lateral coupling capacitance. See “Insights on Lateral Coupling Capacitance Modeling,” p. 9-9 for a theoretical discussion.


Specification

The third group, Maximum Lateral Distance for Lateral Coupling, allows you to specify the maximum distance for the lateral coupling. Refer to “Insights on Lat-eral Coupling Capacitance Modeling,” p. 9-9 for a theoretical discussion.

Two different values can be specified for the same-layer and different-layer lateral couplings. Values are specified by a multiplication factor of the minimum spacing. In different-layer coupling, it multiplies by the minimum spacing of the bottom layer. When the final distance resulting from the minimum spacing multiplied by the factor is larger than the maximum spacing, the maximum spacing is used instead of the distance obtained from the factor specified.

Since the distance factor for different-layer coupling is more susceptible to the third-body effect, it should be smaller than the factor for same-layer coupling.

Note:If you need to specify the maximum distance arbitrarily, change the maximum spacings in the LPE Tools Interface window (Figure 9-1) to the distances you desire first. Then, set the factor value to be large enough so that the resulting distances (factor times the minimum spac-ings) are larger than the maximum spacings.


CapacitanceModeling

Most LPE tools compute the lateral coupling capacitance based on two-body interaction only. These tools compute the lateral coupling capacitance between two traces without considering neighboring third-body traces that are not part of the capacitance terminals (nodes). By neglecting the possible presence of third-body traces, the charge sharing effect of the third-body traces is ignored, and the coupling capacitance is, in turn, significantly overestimated. This is one of the major reason why the capacitance values obtained from LPE tools are often higher than true values.

Figure 9-8 illustrates why the lateral coupling capacitance model for nonadjacent layers should be excluded. Figure 9-9 illustrates why the maximum distance to be considered for lateral coupling capacitance should be limited.

A 2006.03 9-9

Draft 2/6/06


Group 4: OutputUnit

Specification




Conductor 1

Conductor 2

CapacitanceTerminal

Conductors



CapacitanceTerminal

Conductors


9-10 RA 2006.03

Draft 2/6/06


R

8. LP

E To

ols

Diva-V

amp

ire

Diva & Vampire Page

In the Diva & Vampire page (Figure 9-10) of the LPE Tools Interface Options window (Figure 9-1), specify options for Diva and Vampire syntax. This page consists of three groups, which are explained in the following sections.


Modeling

The first group, Non-Interacting Metal Layers, allows you to specify either effective top or bottom ground planes for modeling non-interacting (nonterminal) metal layers. By default, non-interacting metal layers are ignored during capaci-tance model generation. For example, for the capacitance model between Metal 1 and Metal 2, Poly or any other metal layers are not considered during model gen-eration.

Figure 9-11 (a) shows the default structure used to model the overlap capacitance between Metal 1 and Metal 2 in a three-metal-layer technology. Figure 9-11 (b) shows additional structures that is also used for modeling the same overlap capac-itance by treating all possible neighboring metal layers as effective ground planes.

By enabling the Modeled as effective top/bottom ground planes button, the capacitance models generated by the structures shown in Figure 9-11 (b) are also

Figure 9-10 Diva & Vampire page of LPE Tools Interface Options window

A 2006.03 9-11

Draft 2/6/06


included in rule decks. To include all of the capacitance models generated by con-sidering all possible neighboring metal layers as effective ground planes (Figure 9-11 (b)), select the All layers button.

To replace the default model (Figure 9-11 (a)) with the capacitance model gener-ated by considering only the nearest neighboring conductor(s) as the effective ground plane(s), select the Adjacent layers only button. In the above example, instead of using the structure shown in Figure 9-11 (a), the structure shown at the bottom of Figure 9-11 (b) is used to generate the capacitance model between Metal 1 and Metal 2. The capacitance model using this option results in the least capacitance value.

CAUTIONIf you selected the All layers button, you must select (i.e., cut and paste) the capacitance model among many that best fits your design. The Diva & Vam-pire syntax only allows one capacitance model for the overlap capacitance be-tween two given metal layers.

Figure 9-11 (a) Default capacitance model derived using the structure of every two interacting layers (Metal 1 and 2) and substrate (b) Additional structures and models used when Modeled as effective top/bottom ground planes option is selected


Metal 1Metal 2

(a) Default Structure

Ground Plane (Poly)

Metal 1

Metal 2


Metal 1

Metal 2



Ground Plane (Poly)

Metal 1

Metal 2


+

9-12 RA 2006.03

Draft 2/6/06


R

8. LP

E To

ols

Diva-V

amp

ire

Figure 9-12 lists the overlap capacitance outputs of Figure 9-11 using the Modeled as effective top/bottom ground planes button and selecting the All layers option. To simplify the output listing, the As a function of lateral spacing option is not used.

Group 2:Perimeter

CoefficientSetting

In the second group, Perimeter Coefficient of the Diva & Vampire page (Figure 9-10), there are three options to alter the perimeter coefficients. These options are described in the following sections.

Sidewall up anddown Format

Choosing the Split into side-wall up & down components button sets the perim-eter capacitance between two metal layers to be split into the sidewall up/down

Figure 9-12 Overlap capacitance models for Figure 9-11 using Diva & Vampire syntax

; STRUCTURE: Metal_2 above Metal_1; with BULK as a bottom ground plane (C1)

; Ccoed: coin_edge_above_gp/Metal_2,Metal_1,substrate; Csd, Csu: arr_cross_above_gp/Metal_2,Metal_1,substrate

cap( Metal_1 Metal_2 0.02302 0.02166 0.0361 0.009065 )

; STRUCTURE: Metal_2 above Metal_1; with Poly as a bottom ground plane (C2)

; Ccoed: coin_edge_above_gp/Metal_2,Metal_1,Poly; Csd, Csu: arr_cross_above_gp/Metal_2,Metal_1,Poly

cap( Metal_1 Metal_2 0.02302 0.02102 0.03609 0.008379 )

; STRUCTURE: Metal_2 above Metal_1; with BULK as a bottom ground plane; and Metal_3 as a top ground plane (C3)

; Ccoed: coin_edge_btwn_gps/Metal_3,Metal_2,Metal_1,substrate

; Csd, Csu: arr_cross_btwn_gps/Metal_3,Metal_2,Metal_1,substrate

cap( Metal_1 Metal_2 0.02302 0.02308 0.02975 0.007751 )

; STRUCTURE: Metal_2 above Metal_1; with Poly as a bottom ground plane; and Metal_3 as a top ground plane (C3)

; Ccoed: coin_edge_btwn_gps/Metal_3,Metal_2,Metal_1,Poly; Csd, Csu: arr_cross_btwn_gps/Metal_3,Metal_2,Metal_1,

Poly

cap( Metal_1 Metal_2 0.02302 0.02243 0.02979 0.007154 )

Additional models including multiple layers

Default model

A 2006.03 9-13

Draft 2/6/06


and the coincident edge components. Figure 9-13 shows the sidewall up/down and coincident edge components.

This format applies to the perimeter capacitance between two metal layers only. The perimeter coefficient between a metal layer to the ground (Conductor 1 to the ground plane in Figure 9-13) is not effected by this option. If this option is not selected, the perimeter capacitance model between two metal layers is calculated using the weighted average of the sidewall up and down components.

Figure 9-14 shows a typical output for the overlap capacitance using the Split into sidewall up & down components option. To simplify the output listing, the As a function of lateral spacing option has not been selected.

Function of LateralSpacing Format

Selecting the As a function of lateral spacing button outputs perimeter capaci-tance as a function of spacing in each interacting layer. If this option is not selected, the perimeter capacitance model is computed at the average lateral spac-ing point. Figure 9-15 shows a typical output using this option. Note that the ratio-nal function expression is used to represent the spacing dependency.


Figure 9-14 Overlap capacitance model using Diva & Vampire syntax with Split into sidewall up & down components option

Conductor 2

Conductor 1

Sidewall down

Sidewall up Coincident edge


Lists the generic structure used to generate the perimetercapacitance model

Area coeff.Sidewall up coeff. Sidewall down coeff.

; STRUCTURE: ME2 above ME1; with BULK as a bottom ground plane (C1).; Ccoed: coin_edge_above_gp/MET2,MET1,substrate; Csd, Csu: arr_cross_above_gp/MET2,MET1,substrate

CM = multiLevelParasitic(layers( BULK POLY ME1 ME2 )cap( ME1 ME2 0.02302 0.02249 0.03519 0.0104 )

Coincidentedge coeff.

9-14 RA 2006.03

Draft 2/6/06


R

8. LP

E To

ols

Diva-V

amp

ire

Figure 9-15 Overlap capacitance model using the Diva & Vampire syntax with As a function of lateral spacing option

; STRUCTURE: ME1 with BULK as a bottom ground plane (C1)

; Cfringe (SL): arr_above_gp/MET1,above,substrate

C2=measureFringe( ME1calculate( l/s*(0.325283+0.0230562*s-0.134594*s*s+.0894107*s*s*s-0.00950441*s*s*s*s)/(1-1.09006*s-0.601937*s*s+0.784433*s*s*s-0.0785249*s*s*s*s))ML FL2 sep <= 1.2 opposite )

CM=multiLevelParasitic( layers( BULK POLY ME1 ME2 )


; Ccoed: coin_edge_above_gp/MET2,MET1,substrate; Csd, Csu: arr_cross_above_gp/MET2,MET1,substrate

cap( ME1 ME2 0.02302 0.03341 0.03718 0.0104fringe( ME1 FL2 vertical(0.00150533 + 0.0187884*s - 0.0237628*s*s+ 0.00609931*s*s*s)/(1 - 1.31834*s + 0.26585*s*s+ 0.0255036*s*s*s) - 0.03341 )fringe( ME2 FL3 vertical((0.0432239-0.0371401*s+0.00808581*s*s)/(1-0.867492*s+0.19127*s*s)-0.03718 )+ 0.0255036*s*s*s) - 0.03341 )

) )

Makes the sidewall down component be a function of


Lists the generic structure used to generate the coupling capacitancebetween the same layer.

Defines this layer name so it can be used in the overlapcapacitance statement listed below.

The coupling capacitance is described by a function of spacing

Lists the generic structure used to generate the coupling capacitancebetween the same layer.Describes the layer configuration

the top conductor spacingMakes the sidewall up component be a function ofthe bottom conductor spacing

; STRUCTURE: ME2 with BULK as a bottom ground plane (C1)

; Cfringe (SL): arr_above_gp/MET2,above,substrate

C3=measureFringe( ME2calculate(l/s*(0.160279-0.410922*s+0.126121*s*s)/(1-4.07781*s+1.3266*s*s)ML FL3 sep <= 2.8 opposite )

A 2006.03 9-15

Draft 2/6/06


Use Simple SyntaxOnly

Diva has two commands to define the parasitic capacitances: the measurePar-asitic and multiLevelParasitic commands. In the previous output list-ings, the multiLevelParasitic command, which is a more general format than the other, is used. The measureParasitic command can be used only for constant perimeter coefficients, and is not available for Vampire. Refer to the Diva Interactive Verification Reference manual for further information.

The output listing for the previous case (Figure 9-14) using the measurePara-sitic command is shown in Figure 9-16.

Group 3:Capacitance

Model

The last group of the Diva & Vampire page (Figure 9-10) allows you to specify additional options.

Include GroundedKeyword

This option may only be used with Diva. It adds the keyword grounded to capaci-tance models for the total capacitance computation. Refer to the Diva Interactive Verification Reference manual for further information.

Limit ValueSpecification

Both Diva and Vampire allow you to specify the minimum capacitance value to be considered. Any calculated capacitance that is smaller than this value is ignored.

To specify this value, select the button labeled Ignore the capacitance values smaller than and enter the numbers for the overlap and fringing (coupling) capac-itances.

Figure 9-16 Overlap capacitance model using Diva syntax with the Use simple syntax only option


; Area Capacitance:CA12=measureParasitic( area(ME2 over ME1)0.02302 two_net ); Cfringe (SL): arr_above_gp/MET1,above,substrate

; Ccoed: coin_edge_above_gp/MET2,MET1,substrateCCOED12=measureParasitic( length(ME2 coincident ME1)

0.0104 two_net ); Csd, Csu: arr_cross_above_gp/MET2,MET1,substrateCSD12=measureParasitic( length(ME2 inside ME1)

0.03519 two_net )CSU12=measureParasitic( length(ME2 inside ME1)

0.02249 two_net ); Total Overlap Capacitance:CT12=calculateParasitic( CA12 + CCOED12 + CSU12 + CSD12 )

9-16 RA 2006.03

Draft 2/6/06


R

8. LP

E To

ols

Diva-V

amp

ire

Button Operations


• Apply: apply and save changes.





You can save the current LPE options to file and load the saved file using the file menu (Figure 9-17) in the LPE Interface Options window (Figure 9-5).

SRAM ExampleIn this section, a SRAM example is used to show the Diva results with the capaci-tance models generated by the LPE tools interface. Figure 9-18 shows the layout view of this SRAM cell and Figure 9-19 shows the full-3D view.

The result, obtained by a rigorous 3D field solver (Raphael-NES), is used to ver-ify the accuracy of data obtained from the LPE tool. The LPE layer information is the same as shown in Figure 9-1. The LPE interface options used are shown in Figure 9-20 and Figure 9-21.

The comparison is shown in Figure 9-22. Another simulation is also performed using the same setting, except that only 2D structures are used to model the perim-eter coefficients. See “Group 1: Perimeter Coefficient Modeling,” p. 9-5. The results are also shown in Figure 9-22.

The simulation result of a 2x2 SRAM array (Figure 9-23) is also performed using the original options. The results are shown in Figure 9-24.


A 2006.03 9-17

Draft 2/6/06




9-18 RA 2006.03

Draft 2/6/06


R

8. LP

E To

ols

Diva-V

amp

ire


Figure 9-21 Diva & Vampire page setting used for the SRAM example

A 2006.03 9-19

Draft 2/6/06


Figure 9-22 Comparison of Diva and full-3D Raphael-NES capacitances (in fF) for a single SRAM cell. The Diva 3D (and 2D) results were obtained by using 3D crossover (and 2D parallel) structures to generate the perimeter coefficients

NODE Raphael-NES Diva (3D) Diva (2D)

BIT 3.17 3.38 (+6%) 2.93 (-8%)

NOT_BIT 3.20 3.38 (+6%) 2.94 (-8%)

VDD 2.59 2.51 (-3%) 2.37 (-8%)

GND 2.92 3.17 (+9%) 2.85 (-2%)

S_M1_1 5.58 6.34 (+14%) 5.97 (+7%)

S_M1_0 5.50 6.39 (+16%) 6.02 (+9%)

WORD 2.09 2.34 (+12%) 2.27 (+9%)


9-20 RA 2006.03

Draft 2/6/06


R

8. LP

E To

ols

Diva-V

amp

ire

Figure 9-24 Comparison of Diva and full-3D (Raphael-NES) capacitances (in fF) for a 2x2 SRAM array. The 3D crossover structure was used to extract the perimeter coefficients

NODE Raphael-NES

Diva (3D)

BIT 7.04 7.52 (+7%)

NOT_BIT 6.99 7.53 (+8%)

VDD 5.10 5.08 (0%)

GND 5.40 6.06 (+12%)

S_M1_1 5.62 6.30 (+12%)

S_M1_0 5.62 6.35 (+13%)

WORD 4.01 4.42 (+10%)

A 2006.03 9-21

Draft 2/6/06

9-22 RA 2006.03
Draft 2/6/06

CHAPTER 10

R

9. LP

E To

ols

xCalib

re -IC

extract

LPE Tools Interface: xCalibre and ICextract10

OverviewIn this chapter you learn how to generate the rule decks for parasitic capacitance coefficients in the syntax of xCalibre and ICextract, both of which are Mentor Graphics LPE tools.

The interface between Raphael and LPE tools provides a fast and consistent way to generate LPE rule decks with accurate interconnect parasitic capacitance coeffi-cients and equations. Currently, the interface also supports Cadence’s Dracula (see Chapter 8, LPE Tools Interface: Dracula), Diva and Vampire (see Chapter 9, LPE Tools Interface: Diva and Vampire).

To invoke the desired LPE Tools interface:


2. Click the desired database name from the list displayed in the Select a data-base panel. See Chapter 3 if a database has not been created.

3. If you are an authorized licensed user of the interface, click the LPE Tools Interface button to open the LPE Tools Interface window (Figure 10-1).

A 2006.03 10-1

Draft 2/6/06



• The capacitance between two conductors can be divided into the overlap (i.e., area and perimeter) and lateral coupling capacitances. Figure 10-2 illustrates each of these components in more detail.


Perimeter capacitance between two conductors consists of sidewall up and sidewall down components.

If the top conductor’s edge (Conductor 2) above the bottom conductor (Conductor 1) is used to extract the capacitance, then it is a sidewall down case. If the bottom conductor’s edge below the top conductor is used, then it is a sidewall up case. (See Figure 10-2.)

The perimeter capacitance value also depends on the spacing between neigh-boring conductors in the same metal level.


• Lateral coupling capacitance can be divided into same-layer and different-layer coupling components. In Figure 10-2, the same-layer lateral coupling capacitance is shown as component C. The different-layer lateral coupling is shown as component D.


10-2 RA 2006.03

Draft 2/6/06

Raphael Tutorial xCalibre and ICextract LPE Interface

9. LP

E To

ols

xCalib

re -IC

extract

xCalibre andICextract

Terminology

In the xCalibre or ICextract manual (syntax), the overlap capacitance between two metal layers is referred to as a crossover capacitance; whereas, the overlap capaci-tance between a metal to ground (substrate) is called an intrinsic capacitance. Both intrinsic and crossover capacitances are divided into plate (area) and fringe (perimeter) components. All lateral coupling capacitances are named as nearbody capacitances.

xCalibre and ICextract LPE InterfaceThe steps involved in generating the rule files for parasitic capacitance coeffi-cients in the syntax of xCalibre and ICextract are:

1. Selecting the target LPE format to xCalibre and ICextract

2. Changing layer information (optional)

3. Specifying options (optional)

4. Generating the rule file

The following paragraphs describe each of the above steps in more detail.


Conductor 2

Conductor 1

Ground Plane

C

A

Legend:


A

B B

A B

B

D

RA 2006.03 10-3

Draft 2/6/06

xCalibre and ICextract LPE Interface Raphael Tutorial

Step 1: Selecting the Target LPE Format

To choose the target LPE format to xCalibre or ICextract, select the xCalibre and ICextract item from the 1.LPE Tool Format menu.

Step 2: Changing the Layer Information (optional)

When the LPE Tools Interface window (Figure 10-1) opens, the technology information for conductor layers is displayed in the LPE Layer Information panel of the LPE Tools Interface window. All the information in this section can be overridden. For instance, the ranges for width and spacing of conductors can be reduced so that they correspond more closely to the actual layouts. Layer names can also be overridden by editing directly in the LPE Layer Information panel. The modified information can be saved into a file and reloaded later using the File menu shown in Figure 10-3.

Note:The modified min and max values cannot be outside the simulation ranges. The LPE Tools Interface window automatically resets out-of-range values to either the minimum or maximum of simulation ranges.


Raphael provides various options for the LPE interface to help generate more accurate capacitance models. The default option setting gives accurate capaci-tance coefficients for a wide range of designs. However, more accurate coeffi-cients may be obtained by changing the available options to fit your particular design.

Note:Each database has a set of preferences that must be set independently.

To change the options, in the LPE Tools Interface window menu bar, execute Options➔Preferences. This opens the LPE Tools Interface Options window. This window consists of four pages. Two pages, the General (Figure 10-5) and xCalibre & ICextract (Figure 10-10) pages, are relevant to the Dracula interface. See “LPE Tools Interface Option Setting,” p. 10-5 for a detailed discussion.

Figure 10-3 File operations for the conductor layer information

10-4 RA 2006.03

Draft 2/6/06

Raphael Tutorial LPE Tools Interface Option Setting

R

9. LP

E To

ols

xCalib

re -IC

extract


To generate the rule files for parasitic capacitance coefficients for interconnect layers, click the Generate LPE File… button in the LPE Tools Interface window (Figure 10-1). The final rule file is displayed in the Output Terminal window as shown in Figure 10-4. The rule file can be edited directly in the window. To save the rule file into a file, execute File➔Save File As… in the menu bar of the Out-put Terminal window.

LPE Tools Interface Option SettingThis section teaches you how to set the LPE Tools Interface Options window for Dracula. The General and xCalibre & ICextract pages of the option window are discussed in detail.

General Page

The General page, shown in Figure 10-5 of the LPE Tools Interface Options window, presents the options for LPE tools. The page is divided into four areas described in the following sections.

Figure 10-4 Output Terminal window of xCalibre & ICextract interface

A 2006.03 10-5

Draft 2/6/06

LPE Tools Interface Option Setting Raphael Tutorial

Group 1:Perimeter

CoefficientModeling

The first group, Perimeter Coeff. btwn Metal Layers, specifies the model to be used for the perimeter coefficient (overlap capacitance) between two metal layers.




• Alternating 2D and 3D models: 2D structures are used for the perimeter coefficient between parallel metal layers. 3D crossover structures are used for the metal layers running orthogonally. For this model, any two adjacent metal layers are assumed to run orthogonally. For instance, poly-metal 1, metal 1-metal 2, metal 2-metal 3, and poly-metal 3 run orthogonally, whereas poly-metal 2 and metal 1- metal 3 run in parallel.


Figure 10-5 General page of LPE Tools Interface Options window

10-6 RA 2006.03

Draft 2/6/06


R

9. LP

E To

ols

xCalib

re -IC

extract

Figure 10-6 shows the overlap capacitance models using 2D and 3D structures. As shown in this figure, the perimeter coefficient value from the 3D structure is higher than the value for the 2D structure, as expected.

The following paragraphs present a theoretical background on modeling the perimeter coefficient (overlap capacitance).


CoefficientModeling




A 2006.03 10-7

Draft 2/6/06


Figure 10-6 Overlap capacitance models based on 2D and 3D structures using the xCalibre (& ICextract) syntax

// STRUCTURE: ME2 above ME1// with BULK as a bottom ground plane.

// Plate componentsCAPACITANCE CROSSOVER PLATE ME2 ME1[ PROPERTY C C = 0.02302 * AREA()]// Side-wall down componentCAPACITANCE CROSSOVER FRINGE ME2 ME1[ PROPERTY C max_distance = 2.8 IF ( DISTANCE() > 0) C = 0.07194 * LENGTH()*(1.0-EXP(-0.2592*DISTANCE())) ELSE C = 0.03718 * LENGTH()]// Side-wall up componentCAPACITANCE CROSSOVER FRINGE ME1 ME2[ PROPERTY C max_distance = 2.6 IF ( DISTANCE() > 0) C = 0.1316 * LENGTH()*(1.0-EXP(-0.1156*DISTANCE())) ELSE C = 0.03416 * LENGTH()]


// Plate componentsCAPACITANCE CROSSOVER PLATE ME2 ME1[ PROPERTY C C = 0.02302 * AREA()]// Side-wall down componentCAPACITANCE CROSSOVER FRINGE ME2 ME1[ PROPERTY C max_distance = 2.8 IF ( DISTANCE() > 0) C = 0.04113 * LENGTH()*(1.0-EXP(-0.3326*DISTANCE())) ELSE C = 0.02492 * LENGTH()]// Side-wall up componentCAPACITANCE CROSSOVER FRINGE ME1 ME2[ PROPERTY C max_distance = 2.6 IF ( DISTANCE() > 0) C = 0.0347 * LENGTH()*(1.0-EXP(-0.3608*DISTANCE())) ELSE C = 0.02112 * LENGTH()]



10-8 RA 2006.03

Draft 2/6/06


R

9. LP

E To

ols

xCalib

re -IC

extract


Specification

The second group, Maximum No. of Adjacent Layers to be Extracted, specifies the maximum number of adjacent layers for the overlap and lateral coupling capacitances.

OverlapCapacitance

Set the default number of adjacent layers for the overlap capacitance to 10. For processes with less than 12 metal layers, this default value includes the overlap capacitances for all combinations of metal layers.

If you set this value to 1, only the overlap capacitance model between neighboring layers is included. For instance, the overlap capacitance between metal 1 to metal 2 is generated, but the overlap capacitance model between poly to metal 2 is not generated.

If you set the value to 0, no overlap capacitance model between metal layers is included in the output rule file.


Lateral CouplingCapacitance

For lateral coupling, the default number of adjacent layers is set to 1, which includes the same-layer lateral coupling and \ lateral coupling between the nearest neighboring conductors only. For instance, metal 1 to metal 1, metal 1 to metal 2, and metal 1 to poly lateral coupling capacitance models are generated, but metal 1 to the metal 3 lateral coupling capacitance model is not generated.



Ground Plane

C


B B

C A A


A A

A 2006.03 10-9

Draft 2/6/06


CAUTIONDo not specify the number of adjacent layers to be more than 1 for lateral coupling. Including non-nearest layers may result in significant overestima-tion of your lateral coupling capacitance. See “Insights on Lateral Coupling Capacitance Modeling,” p. 10-10 a theoretical discussion.


Specification

The third group, Maximum Lateral Distance for Lateral Coupling, allows you to specify the maximum distance for lateral coupling. Refer to “Insights on Lateral Coupling Capacitance Modeling,” p. 10-10 for a theoretical discussion.

Two different values can be specified for the same-layer and different-layer lateral couplings. Values are specified by a multiplication factor of the minimum spacing. In different-layer coupling, it multiplies by the minimum spacing of the bottom layer. When the final distance resulting from the minimum spacing multiplied by the factor is larger than the maximum spacing, the maximum spacing is used instead of the distance obtained from the factor specified.

Since the distance factor for the different-layer coupling is more susceptible to the third-body effect, it should be smaller than the factor for same-layer coupling.

Note:If you need to specify the maximum distance arbitrarily, change the maximum spacings in the LPE Tools Interface window (Figure 10-1) to the distances you desire first. Then, set the factor value large enough so that the resulting distances (factor times the minimum spacings) are larger than the maximum spacings.


CapacitanceModeling

Most LPE tools compute the lateral coupling capacitance based on two-body interaction only. These tools compute the lateral coupling capacitance between two traces without considering neighboring third-body traces that are not part of the capacitance terminals (nodes). By neglecting the possible presence of third-body traces, the charge sharing effect of the third-body traces is ignored, and the coupling capacitance is, in turn, significantly overestimated. This is one of the major reason why the capacitance values obtained from LPE tools are often higher than true values.

Figure 10-8 illustrates why the lateral coupling capacitance model for nonadjacent layers should be excluded. Figure 10-9 illustrates why the maximum distance to be considered for lateral coupling capacitance should be limited.

10-10 RA 2006.03

Draft 2/6/06


R

9. LP

E To

ols

xCalib

re -IC

extract

Group 4: OutputUnit

Specification


xCalibre & ICextract Page

In the xCalibre & ICextract page (Figure 10-10) of the LPE Tools Interface Options window (Figure 10-1), specify options for the xCalibre and ICextract sections. This page consists of three groups, which are explained in the following sections.



Conductor 1

Conductor 2

CapacitanceTerminal

Conductors



CapacitanceTerminal

Conductors


A 2006.03 10-11

Draft 2/6/06



Modeling

The first group, Non-Interacting Metal Layers, specifies either effective top or bottom ground planes for modeling noninteracting (no-terminal) metal layers. By default, all noninteracting metal layers are modeled as effective ground planes. By disabling the button labeled Modeled as effective top/bottom ground planes, you can ignore noninteracting metal layers during capacitance model generation. For example, for the capacitance model between Metal 1 and Metal 2, Poly, or any higher metal layers are not considered during model generation.

Figure 10-11 (a) shows the basic structure used to model the overlap capacitance between Metal 1 and Metal 2 in a three-metal-layer technology. Figure 10-11 (b) shows additional structures that can also used for modeling the same overlap capacitance by treating all possible neighboring metal layers as effective ground planes.

By enabling the Modeled as effective top/bottom ground planes button, the capacitance models generated by the structures shown in Figure 10-11 (b) are also included in rule decks. To include all of the capacitance models generated by con-sidering all possible neighboring metal layers as effective ground planes (Figure

Figure 10-10 xCalibre & ICextract page of LPE Tools Interface Options window

10-12 RA 2006.03

Draft 2/6/06


R

9. LP

E To

ols

xCalib

re -IC

extract

10-11 (b)), select the All layers button. Selecting this option results in the most accurate capacitance models.

To include the capacitance model generated by considering only the nearest neigh-boring conductor(s) as the effective ground plane(s) in addition to the basic model (Figure 10-11 (a)), select the Adjacent layers only button. In the above example, in addition to the capacitance model generated using the structure shown in Figure 10-11 (a), an additional capacitance model using the structure shown at the bottom of Figure 10-11 (b) is also generated between Metal 1 and Metal 2. This option gives a good balance of accuracy and CPU time.

Note:Unlike the Dracula or Diva syntax, the xCalibre syntax allows more than one capacitance model to be defined (using the Inside Of option) for the overlap capacitance between two given metal layers. During capacitance extraction, the proper capacitance model is automatically used among several models based on the existence of the third-bodies above and/or below the two metal layers.

Figure 10-11 (a) Basic capacitance model derived using the structure of every two interacting layers (Metal 1 and 2) and substrate (b) Additional structures and models used when Modeled as effective top/bottom ground planes option is selected


Metal 1Metal 2

(a) Basic Structure

Ground Plane (Poly)

Metal 1

Metal 2


Metal 1

Metal 2



Ground Plane (Poly)

Metal 1

Metal 2


+

A 2006.03 10-13

Draft 2/6/06


Figures 10-12 and 10-13 list the overlap capacitance outputs using xCalibre and ICextract syntax with the Modeled as effective top/bottom ground planes but-ton and selecting the All layers option.

Figure 10-12 Basic overlap capacitance models for Figure 10-11 using xCalibre & ICextract syntax

// STRUCTURE: Metal_2 above Metal_1// with BULK as a bottom ground plane.

// Plate componentsCAPACITANCE CROSSOVER PLATE Metal_2 Metal_1[ PROPERTY C C = 0.02302 * AREA()]// Side-wall down componentCAPACITANCE CROSSOVER FRINGE Metal_2 Metal_1[ PROPERTY C max_distance = 2.8 IF ( DISTANCE() > 0) C = 0.07144 * LENGTH() * (1.0 - EXP(-0.2721 * DISTANCE())) ELSE C = 0.03822 * LENGTH()]// Side-wall up componentCAPACITANCE CROSSOVER FRINGE Metal_1 Metal_2[ PROPERTY C max_distance = 2.6 IF ( DISTANCE() > 0) C = 0.1163 * LENGTH() * (1.0 - EXP(-0.1268 * DISTANCE())) ELSE C = 0.03267 * LENGTH()]

10-14 RA 2006.03

Draft 2/6/06


R

9. LP

E To

ols

xCalib

re -IC

extract

Group 2:Regression

EquationSelection

In the Regression Equation area of the xCalibre & ICextract page(Figure 10-10), select the regression equations. Currently, there are two sets of equations available: Basic Equations and Advanced Equations.

Basic Equations correspond to the built-in equations of xCalibre and ICextract, except for some slight modifications. Advanced Equations are more complicated and often result in higher accuracy than xCalibre Basic Equations. Advanced Equations use such built-in xCalibre and ICextract functions as width1() and width2().

Figures 10-14 and 10-15 show the crossover capacitance models generated based on the basic and advanced equations. Figure 10-16 shows the lateral coupling model using the advanced equations.

Figure 10-13 Additional overlap capacitance model for Figure 10-11 using xCalibre & ICextract syntax

// STRUCTURE: Metal_2 above Metal_1// with Poly as a bottom ground plane.

// Plate componentsCAPACITANCE CROSSOVER PLATE Metal_2 Metal_1 INSIDE OF Poly[ PROPERTY C C = 0.02302 * AREA()]// Side-wall down componentCAPACITANCE CROSSOVER FRINGE Metal_2 Metal_1 INSIDE OF Poly[ PROPERTY C max_distance = 2.8 IF ( DISTANCE() > 0) C = 0.07094 * LENGTH() * (1.0 - EXP(-0.2748 * DISTANCE())) ELSE C = 0.0382 * LENGTH()]// Side-wall up componentCAPACITANCE CROSSOVER FRINGE Metal_1 Metal_2 INSIDE OF Poly[ PROPERTY C max_distance = 2.6 IF ( DISTANCE() > 0) C = 0.06973 * LENGTH() * (1.0 - EXP(-0.2193 * DISTANCE())) ELSE C = 0.0303 * LENGTH()]

A 2006.03 10-15

Draft 2/6/06


Figure 10-14 Crossover capacitance model using basic equations of xCalibre & ICextract


// Plate componentsFigure 11-31 compares the overlap capacitance outputs using 2-D and 3-D strucCAPACITANCE CROSSOVER PLATE ME2 ME1[ PROPERTY C C = 0.02302 * AREA()]

// Side-wall down componentCAPACITANCE CROSSOVER FRINGE ME2 ME1[ PROPERTY C max_distance = 2.8 IF ( DISTANCE() > 0) C = 0.07194 * LENGTH() * (1.0 - EXP(-0.2592 * DISTANCE())) ELSE C = 0.03718 * LENGTH()]

// Side-wall up componentCAPACITANCE CROSSOVER FRINGE ME1 ME2[ PROPERTY C max_distance = 2.6 IF ( DISTANCE() > 0) C = 0.1316 * LENGTH() * (1.0 - EXP(-0.1156 * DISTANCE())) ELSE C = 0.03416 * LENGTH()]


AreaComponent

Sidewall DownComponent

Sidewall UpComponent

10-16 RA 2006.03

Draft 2/6/06


R

9. LP

E To

ols

xCalib

re -IC

extract

Figure 10-15 Crossover capacitance model using advanced equations of xCalibre & ICextract

Figure 10-16 Lateral coupling using the advanced equations


// Plate componentsCAPACITANCE CROSSOVER PLATE ME2 ME1[ PROPERTY C C = 0.02302 * AREA()]

// Side-wall down componentCAPACITANCE CROSSOVER FRINGE ME2 ME1[ PROPERTY C max_distance = 2.8 IF ( DISTANCE() > 0) C = 0.1601 * LENGTH() * (1.0 - EXP(-0.04655 -

0.07776 * DISTANCE())) ELSE C = 0.03718 * LENGTH()]

// Side-wall up componentCAPACITANCE CROSSOVER FRINGE ME1 ME2[ PROPERTY C max_distance = 2.6 IF ( DISTANCE() > 0) C = 0.07119 * LENGTH() * (1.0 - EXP(0.03897 -

0.2625 * DISTANCE())) ELSE C = 0.03378 * LENGTH()]

AreaComponent

Sidewall DownComponent

Sidewall UpComponent

// STRUCTURE: POLY with BULK as a bottom ground plane. CAPACITANCE NEARBODY POLY WITH SHIELD POLY[ PROPERTY C max_distance = 1.8 max_width = 0.9 C = 0.1865 * LENGTH() * (1.0 - 1.0/ ( 1.849 + 0.2814 * width1() * width2() * DISTANCE() )) * POW( ABS( DISTANCE() + 0.7945 ), -1.986 )]

// STRUCTURE: ME1 with BULK as a bottom ground plane. CAPACITANCE NEARBODY ME1 WITH SHIELD ME1[ PROPERTY C max_distance = 1.8 max_width = 2.6 C = 0.08994 * LENGTH() * (1.0 - 1.0/ ( 3.748 + 0.957 * width1() * width2() * DISTANCE() )) * POW( ABS( DISTANCE() + 0.2025 ), -1.004 )]

A 2006.03 10-17

Draft 2/6/06


Group 3: OutputFormat

In the last group of the xCalibre & ICextract page (Figure 10-10), you can specify additional options to change the output format.

Print RegressionInformation

By enabling this option, regression information is also output. The following lines show typical output:

// Iter= 64, RMS Error= 0.607%, Max Value= 0.09685// Max. Error= 0.4742%, at W= 1.7, S= 0.6, Exact Value= 0.09236

This particular case took 64 iterations, with an absolute RMS error of 0.607%. The maximum absolute error is 0.4742% at w = 1.7 and s = 0.6. The exact (simu-lated) value at this point is 0.09236. The maximum capacitance value is also dis-played as 0.09685.

Note:For regression analysis, the absolute error is used for the convergence criterion instead of the relative error. Because of this, you may observe very large relative errors when the maximum error occurs at small capacitance values.

Insert Base LayerName

For the overlap capacitance between a metal to ground (intrinsic capacitance), you may include the base layer name. This feature is useful when the base layer is not a substrate.

Layout ScalingFactor

When the layout scaling factor is used, the length parameters of the equations are scaled by the specified value that effectively scales the entire layout geometry. Figure 10-17 shows an example output using the scaling factor.

Button Operations


• Apply: apply and save changes




10-18 RA 2006.03

Draft 2/6/06


R

9. LP

E To

ols

xCalib

re -IC

extract


You can save the current LPE options to file and load the saved file using the file menu (Figure 10-18) in the LPE Interface Options window (Figure 10-5).

B

Figure 10-17 Crossover capacitance model using the layout scaling factor


VARIABLE FACTOR 0.6

// STRUCTURE: MET2 above MET1// with BULK as a bottom ground plane.

// Plate componentsCAPACITANCE CROSSOVER PLATE MET2 MET1 MASK[ PROPERTY C C = 0.02302 * AREA() * FACTOR * FACTOR]// Side-wall down componentCAPACITANCE CROSSOVER FRINGE MET2 MET1 MASK[ PROPERTY C max_distance = 2.8 / FACTOR IF ( DISTANCE() > 0) C = 0.03076 * LENGTH() * FACTOR *

(1.0 - EXP(0.5957 - 0.8021 * DISTANCE() * FACTOR)) ELSE C = 0.02485 * LENGTH() * FACTOR]// Side-wall up componentCAPACITANCE CROSSOVER FRINGE MET1 MET2 MASK[ PROPERTY C max_distance = 2.6 / FACTOR IF ( DISTANCE() > 0) C = 0.03217 * LENGTH() * FACTOR *

(1.0 - EXP(0.02255 - 0.4169 * DISTANCE() * FACTOR)) ELSE C = 0.02104 * LENGTH() * FACTOR

A 2006.03 10-19

Draft 2/6/06


SRAM ExampleIn this section, an SRAM example is used to show the xCalibre results with the capacitance models generated by the LPE interface. Figure 10-19 shows the lay-out view of this SRAM cell and Figure 10-20 shows the full-3D view.

The result, obtained by a rigorous 3D field solver (Raphael-NES), is used to ver-ify the accuracy of data obtained from the LPE tool. The LPE layer information is the same as shown in Figure 10-1. The LPE interface options used are shown in Figure 10-21 and Figure 10-22.

The comparison is shown in Figure 10-23. Another simulation is also performed using the same setting, except that only 2D structures are used to model the perim-eter coefficients. See “Group 1: Perimeter Coefficient Modeling,” p. 10-6. The results are also shown in Figure 10-23.

The simulation of a 2x2 SRAM array (Figure 10-24) is also performed using the original option setting. The results are shown in Figure 10-25


10-20 RA 2006.03

Draft 2/6/06


R

9. LP

E To

ols

xCalib

re -IC

extract



A 2006.03 10-21

Draft 2/6/06


Figure 10-23 Comparison of xCalibre and full-3D Raphael-NES capacitances (in fF) for a single SRAM cell. The xCalibre 3D (and 2D) results were obtained by using 3D crossover (and 2D parallel) structures to generate the perimeter coefficients

Figure 10-22 xCalibre & ICextract page setting used for the SRAM example

NODE Raphael-NES xCalibre (3D) xCalibre (2D)

BIT 3.17 3.81 (+20%) 3.25 (+3%)

NOT_BIT 3.20 3.81 (+19%) 3.25 (+2%)

VDD 2.59 2.47 (-5%) 2.30 (-11%)

GND 2.92 3.10 (+6%) 2.78 (-5%)

S_M1_1 5.58 6.18 (+11%) 5.70 (+2%)

S_M1_0 5.50 6.22 (+13%) 5.74 (+4%)

WORD 2.09 2.27 (+9%) 2.19 (+5%)

10-22 RA 2006.03

Draft 2/6/06


R

9. LP

E To

ols

xCalib

re -IC

extract

Figure 10-25 Comparison of xCalibre and full-3D Raphael-NES capacitances (in fF) for a 2x2 SRAM array. The 3D crossover structure was used to extract the perimeter coefficients for xCalibre


NODE Raphael-NES

xCalibre (3D)

BIT 7.04 8.26 (+17%)

NOT_BIT 6.99 8.26 (+18%)

VDD 5.10 4.81 (-6%)

GND 5.40 6.08 (+13%)

S_M1_1 5.62 6.31 (+12%)

S_M1_0 5.62 6.35 (+13%)

WORD 4.01 4.46 (+11%)

A 2006.03 10-23

Draft 2/6/06

10-24 RA 2006.03
Draft 2/6/06

CHAPTER 11

R

10. Field

So

lveres

Field Solvers11

OverviewIn this chapter you learn how to run the five Raphael field solvers—

• RC2 and RC2-BEM: Two-dimensional capacitance, resistance and inductance solvers

• RC3and RC3-BEM: Three-dimensional capacitance and resistance solvers

• RI3: Three-dimensional inductance and resistance solver

RC2 and RC2-BEM: 2D Resistance and Capacitance SolversTo access the RC2 and RC2-BEM solvers, in the Field Solvers module of the Raphael main window (Figure 11-1), click the RC2 button to select the RC2 solv-ers. Then, click the icon associated with the Field Solvers module. If the Raphael Field Solvers window is already open, execute Tools➔RC2 from the menu bar.

Step 1: Select Input File

Load an input file by clicking the Browse Input File… button to open a file browser in which you can enter the input file name.

Step 2: Select Options

You may choose several options:

• Click the Check input syntax only button to scan the input file for errors; no calculations are performed. This option corresponds to specifying -i as a command line option.

A 2006.03 11-1

Draft 2/6/06

RC2 and RC2-BEM: 2D Resistance and Capacitance Solvers Raphael Tutorial

• Click Generate graphics file: to create a file that describes the original struc-ture, the calculated potential, or current distribution.

The default name of the graphics file is <input filename>.pot. To assign a dif-ferent name to the graphics file, click the Browse Graphics File… button. A file browser allows you to save the graphics file with a different name. There are two options associated with Generate graphics file:

• The default option is Geometry only. It writes the input geometry in-formation to the graphics file. Choosing this button corresponds to specifying the -p and -x options in the command line.

• The Geometry and potential option writes both the input geometry information and the potential and electric field calculations to the graphics file. Choosing this option corresponds to specifying -p in the command line.

Figure 11-1 Raphael Field Solvers window for RC2

11-2 RA 2006.03

Draft 2/6/06

Raphael Tutorial RC2 and RC2-BEM: 2D Resistance and Capacitance Solvers

R

10. Field

So

lveres

Not selecting this option is equivalent to using the -n option in the com-mand line.

1. Click the Append summary to output button to append a summary to the output file. This button corresponds to specifying -u option in the command line.

2. Click the Send output to file button to write the result to an output file. An output terminal displays the contents of this file following the simulation see Figure 11-2. The default output filename is <input filename>.out. To choose another name for the output file, click the Browse Output File… button. A file browser allows you to save the output file with a different name. Choosing this button corresponds to specifying -o in the command line.

Not choosing this button corresponds to specifying -s.

Figure 11-2 RC2 Output Terminal window

A 2006.03 11-3

Draft 2/6/06

RC3 and RC3-BEM: 3D Resistance and Capacitance Solvers Raphael Tutorial

Step 3: Select Solver

You may choose to run the input file with the finite difference or boundary element method (BEM) solver.

1. Click Finite Difference Method or Boundary Element Method to choose the finite difference solver or the BEM solver.

2. If you choose the Finite Difference Method, you can specify the type of linear equation solver method by clicking the MICCG or ICCG buttons.

3. To specify the discretization scheme for Poisoon’s equation, click the Node Model or Element Model buttons.

4. After you choose the BEM solver, you can specify the type of ground plane at the window boundary in the X direction. Click the toggle X Boundary first.

5. Place a ground plane at the minimum X position by clicking the At Min X but-ton, or at the maximum X position by clicking the At Max X button. However, if two magnetic planes need to be placed at both the minimum and the maxi-mum X position, then click the At Both Min & Max (Magnetic plane only) button.

6. If you place a single ground plane at the minimum or the maximum X posi-tion, then click either the Electrical Plane or Magnetic Plane button to choose the type of plane desired.

Step 4: Run Solver

In the RC2 Field Solver window, click the Run button to start the simulation.

During the simulation, numeric information as well as the status of the simulation is displayed in the UNIX shell from which Raphael was invoked.

You can abort the simulation anytime during the simulation process by clicking the Abort button.

RC3 and RC3-BEM: 3D Resistance and Capacitance SolversOpen the RC3 Field Solver window by clicking the RC3... button in the Field Solvers module of the Raphael main window. If the Raphael Field Solvers window is already open, execute Tools¹¹➔RC3 from the menu bar.

The RC3 Field Solver window consists of two pages:

• Raphael/RC3

• Raphael/QuickCAP

To access the RC3 and RC3-BEM solvers, use the Raphael/RC3 page. If you have Raphael-NES, you also can access the QuickCAP solver through the Raphael/QuickCAP page.

11-4 RA 2006.03

Draft 2/6/06

Raphael Tutorial RC3 and RC3-BEM: 3D Resistance and Capacitance Solvers

R

10. Field

So

lveres

Raphael/RC3 Page

The first page in the RC3 Field Solver window is the Raphael/RC3 page (Figure 11-3). To access the RC3 and RC3-BEM solvers, first click the Raphael/RC3 tab in the RC3 Field Solver window. The procedure for starting a RC3 solver is identical to RC2. The main steps are summarized in the following:

1. Select input file.

2. Select options.

Figure 11-3 Raphael/RC3 3D Interconnect Analyzer window

A 2006.03 11-5

Draft 2/6/06

RI3: 3D Resistance and Inductance Solver Raphael Tutorial

3. Select Solver.

a. You may choose to run the input file with the finite difference solver or boundary element method (BEM) solver.

b. Click Finite Difference Method or Boundary Element Method to choose the finite difference solver or the BEM solver.

c. If you choose the Finite Difference Method, you can specify the type of linear equation solver method by clicking the Advanced, MICCG or ICCG buttons. Advanced corresponds to -N option on the command line and is the default setting for this window

d. The discretization scheme for Poisson’s equation can be specified by clicking the Node Model or Element Model buttons.

e. After choosing the BEM solver, specify the position and the type of ground plane at the window boundary in the X and Y directions. To place a ground plane in the x direction, click the X Boundary toggle. Similarly, to place a ground plane in the Y direction, click the Y Boundary toggle.

f. Similar to the RC2 solver options, the ground plane(s) can be placed at either the minimum or maximum X (and/or Y) position.

g. To place two magnetic ground planes at both the minimum and maximum X (and/or Y) positions, click At Both Min and Max X (Magnetic Plane Only) and/or At Both Min and Max Y (Magnetic Plane Only) buttons.

h. Select the type of ground plane desired at either the minimum or maxi-mum X (and/or Y) by clicking the Electrical Plane or Magnetic Plane buttons.

4. Click Run to start the simulation.

5. To abort the simulation process any time, click the Abort button.

Raphael/QuickCAP Page

The second page in the RC3 Field Solver window is the Raphael/QuickCAP page (Figure 11-4). If you have Raphael-NES (Net Extraction System), you can access the QuickCAP solver by clicking the Raphael/QuickCAP tab in the RC3 Field Solver window. Refer to the Raphael NES User Guide for the description of the options and further information.

RI3: 3D Resistance and Inductance SolverTo open the RI3 Field Solvers window, click the RI3... button in the Raphael main window. If the Raphael Field Solvers window is already open, then execute Tools➔RI3 from the menu bar.

The main steps for invoking the RI3 solver are similar to invoking the RC2 and RC3 solvers. The choice of options is different.

11-6 RA 2006.03

Draft 2/6/06

Raphael Tutorial RI3: 3D Resistance and Inductance Solver

R

10. Field

So

lveres

Step 1: Select Input File

Load an input file by clicking the Browse Input File… button to open a file browser in which you can enter the input file name.

Step 2: Select Options

• The Check input syntax only button allows you to check the input file for errors. No calculations are performed. This button corresponds to the -i option in the command line.

• The Generate graphics file button creates a file containing a description of the original structure. The default name of the graphics file is <input file-name>.geo. To save the graphics file with a different name, click the Browse

A 2006.03 11-7

Draft 2/6/06

RI3: 3D Resistance and Inductance Solver Raphael Tutorial

Graphics File… button. This corresponds to the -g <file> option in the com-mand line. Not choosing this button corresponds to specifying -n

• Set Matrix File Name: specifies the matrix file name. The default name is <input filename>.mat. To save the matrix file name with a different name, click the Browse Matrix File… button. This corresponds to -m <file> option in the command line.

• Generate RC3 file: generates an RC3 input <file> to be used in 3D capaci-tance simulations. The default name of <file> is <input filename>.rc3. To save the RC3 file with a different name, click the Browse RC3 Output File… button. This corresponds to the -m <file> option in the command line.

Figure 11-4 RC3 3D Interconnect Analyzer window

11-8 RA 2006.03

Draft 2/6/06

Raphael Tutorial RI3: 3D Resistance and Inductance Solver

R

10. Field

So

lveres

• Send output to file: writes the result to an output file. An output terminal dis-plays the content of this file following the simulation, as in Figure 11-2. This corresponds to specifying the -o <file> option in the command line. Not choosing this button corresponds to specifying -s <file> option in the com-mand line. The default output filename is <input filename>.out. Click Browse Output File… to choose a different name for your output file.

Step 3: Select Solver

You can specify the type of linear equation solver method by clicking the Advanced or LU Decomposition buttons. Advanced corresponds to -N option on the command line and is the default setting for this window.

Figure 11-5 Raphael Field Solvers window for RI3

A 2006.03 11-9

Draft 2/6/06

Closing the Field Solvers Window Raphael Tutorial

Step 4: Run Solver

Click the Run button to start the RI3 solver. You can abort the simulation any time during the simulation process by clicking the Abort button.

Menu Bar

The menus across the top of the window have the following features:

• The File➔View Input file menu allows you to view the input file once it is loaded.

• The Tools menu allows you to switch to one of RC2 (Tools➔RC2), RC3 (Tools➔RC3), and RI3 (Tools➔RI3) solvers.

• The History menu shows a list of UNIX command lines that have been per-formed since the Raphael Field Solvers window was opened.

To open the Raphael Field Solvers: History window, click the History button see Figure 11-6. You may view the history or repeat some of the previous runs by clicking one of the listed command lines. In this window, you may also edit the command in the space field and then click the Run button to start the simulation.

You can abort the simulation any time during the simulation process by clicking the Abort button.

Closing the Field Solvers WindowTo close the Field Solvers window, click the Close button.

Figure 11-6 Field Solver History window

11-10 RA 2006.03

Draft 2/6/06

CHAPTER 12

R

11. RIL

Lib

rary

Raphael Interconnect Library12

OverviewThe Raphael Interconnect Library (RIL) utility generates and stores electrical model parameters for interconnect elements based on:

• Dimensions

• Geometries

• Material properties

The interconnect elements are geometric structures that can be joined together to form interconnects for various electrical designs.

You can calculate the electrical parameters for these elements by using the numer-ical simulation programs (solvers) RC2, RC3, and RI3. With one or two solvers, you can generate and store single or multiple sets of the electrical model parame-ters for each interconnect element. RIL allows you to generate SPICE subcircuit definitions, and Sysnopsys TCAD’s visualization tool allows you to visually inspect the results.

The RIL tool performs consistent parametric variations of the parameters that characterize the library elements. RIL also analyzes the effect of these variations on the parasitics associated with the interconnect structures. The information flow for RIL and its main components are presented in Figure 12-1.

To interact with RIL:

• Select an element for the library.

• Specify a set of values that defines a set of structures.

RIL then generates the input files, runs the corresponding solvers, and stores the parasitic values in the database for that element of the library.

A 2006.03 12-1

Draft 2/6/06

Overview Raphael Tutorial

You can invoke the Results Inspectors to inspect any database for each of the structures in the Parametrics Library. With this option, you can generate listings and printouts; or you can interactively plot the simulated parasitics versus the parameters that describe the structure.

Parametrics Library of 30 Structures

The Parametrics Library of RIL consists of a set of 30 structures that represent most of the common interconnect structures found in printed circuit boards, multi-chip modules, packaging, and on-chip interconnects. All of these template library elements are listed in Appendix A of the Raphael Reference Manual.

For each library element, a default interconnect database exists under the default name data. You can name other databases to store specific sets of parameters.

Each one of the parametric structures is defined by a set of support files used by RIL for:

• Generating input files

• Parsing outputs generated by the solvers

• Generating interconnect databases

Figure 12-2 shows the structure of the Parametrics Library.

Figure 12-1 Raphael Interconnect Library (RIL) components and information flow

USER

RIL

RC2 RC3 RI3

ParametricsLibrary

InterconnectDatabase

ResultsInspectors(Listing,STUDIOVisualize)

12-2 RA 2006.03

Draft 2/6/06

Raphael Tutorial Invoking RIL

R

11.RIL

Lib

rary

Invoking RILTo launch the Raphael Interconnect Library, click the Interconnect Library but-ton in the Raphael main window. Figure 12-3 displays the module button in the main window. Clicking this button opens a UNIX shell in which you may specify the interactive parameters.

For further details on specifying the parameters, refer to Chapter 7 of the Raphael Reference Manual.

Figure 12-2 Parametrics Library


(data,userdefined)

SupportFiles

Element 12 Pins/Vias …


(data,userdefined)

SupportFiles

Element 30Level 2…

ParametricsLibrary

Figure 12-3 Raphael Interconnect Library (RIL) module button

A 2006.03 12-3

Draft 2/6/06

Invoking RIL Raphael Tutorial
12-4 RA 2006.03
Draft 2/6/06

APPENDIX A

A. C

apacitan

ceD

efinitio

ns

Appendix A: Capacitance Definitions of Raphael Default DatabaseA

This appendix contains figures that define the capacitance terms used in the Raphael parasitics database format. These terms are defined for each of the generic structures shown in Chapter 6.

Capacitance TermsThese capacitance terms appear in the plots of capacitance versus width and spac-ing discussed in Chapter 7. The terms also appear in the list of targets in the Regression Analysis window, Chapter 7, Figure 7-2, p. 7-4.

Note:Starting in Raphael 4.1, the 2D generic structures of “array above/between ground plane(s)” and “parallel arrays above/between ground plane(s)” assume three, instead of five, conductor traces in each metal layer.

RA 2006.03 A-1

Draft 2/6/06

Capacitance Terms Raphael Tutorial

Where:

Where:

Figure A-1 Capacitance terms for “array above a ground plane” generic structure

bottom gp

Ccoupling

Cbottom gp

Ctotal = Cbottom gp + 2 Ccoupling

S

W

Cbottom gp Capacitance of center conductor to bottom ground plane

Ccoupling Coupling capacitance

Figure A-2 Capacitance terms for “array between ground planes” generic structure

bottom gp

Ccoupling

Cbottom gp

Ctotal = Cbottom gp + Ctop gp + 2 Ccoupling

Ctop gp

top gp

W

S

Cbottom gp Capacitance of center conductor to bottom ground plane

Ctop gp Capacitance of center conductor to top ground plane

Ccoupling Coupling capacitance

A-2 RA 2006.03

Draft 2/6/06

Raphael Tutorial Capacitance Terms

R

A. C

apacitan

ceD

efinitio

ns

Figure A-3 Capacitance terms for “array crossover above a ground plane” generic structure

top array

bottom array

bottom gp

top arrayCttot is the total capacitancefor a trace in the top array to all other electrodes in thedashed box.

bottom array

top array

bottom array

Dashed box represents a unit cell of a periodicstructure.

for a trace in the bottom arrayto all other electrodes in the

st

bottom gp

dashed box.

wbsb

Ctop array coupling

Cbottom array coupling

Cbottom array

Cbtot is the total capacitance

Ccross over

wt

A 2006.03 A-3

Draft 2/6/06


Figure A-4 Capacitance terms for “array crossover between ground planes” generic structure

top array

bottom array

bottom gp

top arraycoupling Cttot is the total capacitance

for a trace in the top array to all other electrodes in thedashed box (i.e., a unit cell).

bottom array

top array

bottom array

Cbtot is the total capacitancefor a trace in the bottom arrayto all other electrodes in thedashed box.

st

top gp

trace in the top array to top ground plane in the dashed box.

Cbottom array

bottom gp

Cbottom array coupling

Ctop array

Ccross over

Cttgp is the capacitance for a

sb wb

wt

A-4 RA 2006.03

Draft 2/6/06


R

A. C

apacitan

ceD

efinitio

ns

Where:

Note:Starting in Raphael 4.2, Cbcou, Cbbgp, Cbtcc are no longer extracted.

Figure A-5 Capacitance terms for “two parallel arrays above a ground plane” generic structure

bottom gp

Cbcou

Cbbgp

Wt

Wb

St

Sb

Ctcou

Ctbmc

Ctbcc

Cbtcc

Ctcou Top array coupling capacitance

Cbcou Bottom array coupling capacitance

Cbbgp Capacitance of bottom center conductor to bottom ground plane

Ctbmc Capacitance of top center conductor to bottom center conduc-tors

Ctbcc Cross coupling capacitance between top center and bottom left conductors

Cbtcc Cross coupling capacitance between bottom center and top right conductors

A 2006.03 A-5

Draft 2/6/06


Where:

Note:Starting in Raphael 4.2, Cbcou, Cbbgp, and Cbtcc are no longer extracted.

Figure A-6 Capacitance terms for “two parallel arrays between two ground planes” generic structure

bottom gp

Cbcou

Cbbgp

Wt

Wb

St

Sb

Ctcou

Ctbmc

Ctbcc

Cbtcc

Cttgptop gp

Ctcou Top array coupling capacitance

Cbcou Bottom array coupling capacitance

Cbbgp Capacitance of bottom center conductor to bottom ground plane

Ctbmc Capacitance of top center conductor to bottom center conductor

Ctbcc Cross coupling capacitance between top center and bottom left conductors

Cbtcc Cross coupling capacitance between bottom center and top right conductors

Cttgp Capacitance of top center conductor to top ground plane

A-6 RA 2006.03

Draft 2/6/06


R

A. C

apacitan

ceD

efinitio

ns

Where:

Where:

Figure A-7 Capacitance term for “coincident edge structure above a ground plane” generic structure

bottom gp

Ccoed

W

S

Ccoed Capacitance of top right conductor to bottom right conductor

Figure A-8 Capacitance term for “coincident edge structure between two ground planes” generic structure

Ccoed

W

S

top gp

bottom gp

Ccoed Capacitance of top right conductor to bottom right conductor

A 2006.03 A-7

Draft 2/6/06


Where:

Where:

Figure A-9 Capacitance term for “oversize structure between two ground planes” generic structure

Ctgbg

W

S

top gp

bottom gp

Ctgbg Capacitance between top and bottom ground planes

Figure A-10 Capacitance term for “different layers above a ground plane” generic structure

bottom gp

Wt

Wb

S

Ctbcc

Ctbcc Capacitance of top left conductor to bottom right conductor

A-8 RA 2006.03

Draft 2/6/06


R

A. C

apacitan

ceD

efinitio

ns

Where:

Figure A-11 Capacitance terms for “different layers between two ground planes” generic structure

bottom gp

Wt

Wb

S

Ctbcc

top gp

Ctbcc Capacitance between top left conductor to bottom right conduc-tor

A 2006.03 A-9

Draft 2/6/06

A-10 RA 2006.03
Draft 2/6/06

APPENDIX B

B. R

egressio

nA

nalysis

Appendix B: Regression Analysis Model DefinitionsB

This appendix lists the expressions available to you to fit the simulated results after an interconnect database has been created.

Not all equations are applicable to all structures.

For example, Equations B-1 through B-3 use only one width and one spacing as variables, so they are only applicable to single array structures. Equations B-4 to B-9 use two widths and two spacings and are applicable for structures that involve two arrays (generically called top and bottom arrays). Equation B-10 uses two widths and one spacing as variables and is applicable only for the different-layer structures.

Note:In certain cases, user-defined equations may achieve better regression fit than the models described below.

One Array

Mono decreasing:

Equation B-1C A AP+ w⋅( )

B BP+ w⋅s

----------------------------- C CP+ w⋅

esE---⎝ ⎠

⎛ ⎞----------------------------- D DP+ w⋅

es2

F----⎝ ⎠

⎛ ⎞------------------------------+ + +

=

RA 2006.03 B-1

Draft 2/6/06

Two Crossover Arrays Raphael Tutorial

Mono increasing:

Equation B-2

Coupling:

Equation B-3

Two Crossover Arrays

Mono increasing (bottom array):

Equation B-4

C A AP+ w⋅( )

E11 E11P+ w⋅

eE12

s----------⎝ ⎠

⎛ ⎞----------------------------------------- E21 E21P+ w⋅

eE22s2

----------⎝ ⎠⎛ ⎞

-----------------------------------------

L1 L1P+ w⋅( ) s( )log S11 S11P+ w⋅

1 S12s

---------+----------------------------------------+⋅

+ +

+

=

C A APs

------- Bs w+------------ C

s CP+---------------- D

s w DP+ +---------------------------+ + + +=

C A A1 st wb A2+ wt wb A3+ st wt+( ) sb⋅[ ]A4

B B1 st wb B2 wt wb B3 st wt+( ) sb⋅[ ]B4⋅+⋅ ⋅+⋅ ⋅+{ } sb( )

C C1 st wb C2 wt wb C3 st wt+( ) sb⋅[ ]C4⋅+⋅ ⋅+⋅ ⋅+{ }

eC5sb-------⎝ ⎠

⎛ ⎞------------------------------------------------------------------------------------------------------------------------------------------------------

D D1 st wb D2 wt wb D3 st wt+( ) sb⋅[ ]D4⋅+⋅ ⋅+⋅ ⋅+

1 D5sb-------+⎝ ⎠

⎛ ⎞----------------------------------------------------------------------------------------------------------------------------------------------------

+

+

log⋅+

⋅ ⋅⋅ ⋅ ⋅+=

B-2 RA 2006.03

Draft 2/6/06

Raphael Tutorial Two Crossover Arrays

B. R

egressio

nA

nalysis

Mono increasing (top array):

Equation B-5

Mono decreasing (bottom array):

Equation B-6

C A A1+ sb wt A2 wb wt A3 sb wb+( ) st⋅[ ]A4

B B1 sb wt B2 wt wb B3 sb wb+( ) st⋅[ ]B4⋅+⋅ ⋅+⋅ ⋅+{ } st( )log

C C1 sb wt C2 wt wb C3 sb wb+( ) st⋅[ ]C4⋅+⋅ ⋅+⋅ ⋅+

eC5st

-------⎝ ⎠⎛ ⎞

----------------------------------------------------------------------------------------------------------------------------------------------------

D D2 sb wt D2 wt wb D3 sb wb+( ) st⋅[ ]D4⋅+⋅ ⋅+⋅ ⋅+

1 D5st

-------+⎝ ⎠⎛ ⎞

-----------------------------------------------------------------------------------------------------------------------------------------------------

+

+

⋅+

⋅+⋅ ⋅+⋅ ⋅=

A A1+ st A2 wt A3 st wt+( ) wb⋅[ ]A4⋅+⋅+⋅

B B1+ st B2 wt B3 st wt+( ) wb⋅[ ]B4⋅+⋅+⋅sb

-----------------------------------------------------------------------------------------------------------------------

C C1 st C2 wt B3 st wt+( ) wb⋅[ ]C4⋅+⋅+⋅+

esb

C5-------⎝ ⎠

⎛ ⎞-------------------------------------------------------------------------------------------------------------------------

D D1+ st D2 wt D3 st wt+( ) wb⋅[ ]D4⋅+⋅+⋅

esb

D5-------⎝ ⎠

⎛ ⎞2

--------------------------------------------------------------------------------------------------------------------------

+

+

+

=

RA 2006.03 B-3

Draft 2/6/06

Two Crossover Arrays Raphael Tutorial

Mono decreasing (top array):

Equation B-7

Crossover:

Equation B-8

A A1 sb A2 wb A3 sb wb+( ) wt⋅[ ]A4⋅+⋅+⋅

B B1 sb B2 wb B3 sb wb+( ) wt⋅[ ]B4⋅+⋅+⋅+

st--------------------------------------------------------------------------------------------------------------------------

C C1 sb C2 wb C3 sb wb+( ) wt⋅[ ]C4⋅+⋅+⋅+

est

C5-------⎝ ⎠

⎛ ⎞----------------------------------------------------------------------------------------------------------------------------

D D1 sb D2 wb D3 sb wb+( ) wt⋅[ ]⋅+⋅+⋅+

est

D5-------⎝ ⎠

⎛ ⎞2

-----------------------------------------------------------------------------------------------------------------------

+

+

+

+

=

A A1 wb wt A2 st wt+( ) sb wb+( )⋅[ ]A3⋅+⋅ ⋅

B B1 wb wt B2 st wt+( ) sb wb+( )⋅[ ]B3 sb( )log

C C1 wb wt C2 st wt+( ) sb wb+( )⋅[ ]C3 st( )

D D1 wb wt D2 st wt+( ) sb wb+( )⋅[ ]D3⋅+⋅ ⋅+

eD4sb

-------⎝ ⎠⎛ ⎞

-------------------------------------------------------------------------------------------------------------------------------

E E1 wb wt E2 st wt+( ) sb wb+( )⋅[ ]E3⋅+⋅ ⋅+

eE4st

-------⎝ ⎠⎛ ⎞

-----------------------------------------------------------------------------------------------------------------------------

F F1 wb wt F2 st wt+( ) sb wb+( )⋅[ ]F3⋅+⋅ ⋅+

1 F4sb-------+

-----------------------------------------------------------------------------------------------------------------------------

G G1 wb wt G2 st wt+( ) sb wb+( )⋅[ ]G3⋅+⋅ ⋅+

1 G4st

-------+-------------------------------------------------------------------------------------------------------------------------------

+

+

+

+

log⋅ ⋅+⋅ ⋅++

⋅ ⋅+⋅ ⋅

+

+ +

B-4 RA 2006.03

Draft 2/6/06

Raphael Tutorial Two Parallel Arrays

B. R

egressio

nA

nalysis

Two Parallel Arrays

Rational (1):

Equation B-9

Different Layers

Rational (2):

Equation B-10

C A 1 A1 st⋅ A2 st2⋅+ +( ) 1 A3 wt⋅ A4 wt

2⋅+ +( )1 B sb⋅ B1 sb

2⋅+ +( ) 1 B2 wb B3 wb2⋅+⋅+( )

⋅ ⋅ ⋅⋅

()

1 C st⋅+( ) 1 C1 wt⋅+( ) 1 C2 sb⋅+( ) 1 C3 wb⋅+( )⋅ ⋅ ⋅( )⁄

=

A 1 A1 s⋅ A2 s⋅+ +( ) 1 A3 wt⋅ A4 wt2⋅+ +( )

1 B wb⋅ B1 wb2⋅+ +( )

⋅ ⋅ ⋅()

1 C s⋅ C1 s⋅ C2 s s⋅ ⋅ C3+ + + s2⋅+( )1 B2 wt⋅+( ) 1 B3 wb⋅+( )

⋅⋅

()

⁄

RA 2006.03 B-5

Draft 2/6/06

Different Layers Raphael Tutorial
B-6 RA 2006.03
Draft 2/6/06

APPENDIX C

R

C. R

egressio

n

Defau

lts

Appendix C: Default Regression ModelsC

This appendix describes how you can select the default regression models (DRM) and automate the regression analysis.

Note:Most users can skip this appendix.

DRM File FormatIn the automatic parasitic database generation mode, before creating the database, you can specify the regression models to be used for each capacitance target (such as total capacitance (C_total) or coupling capacitance (C_coupling). You may make these specifications using the Regression page of the User Preferences notebook. Refer to Chapter 5.

A DRM file called default.drm is stored in the Raphael directory hierarchy. To specify your own DRM file from a user-defined directory, you can follow the for-mat described below.

The .drm files contain the absolute DRM numbers to be used during regression analysis. For both manual and batch regression, these files control which models are to be used as the default regression equations for all capacitance targets and generic structures.

For example, the status line at the bottom of the Regression Analysis window (Chapter 7, Figure 7-2, p. 7-4) displays:

The "Mono decreasing" model is recommended for C total.

In the past, the “Mono decreasing” model was hard coded as the default model for the C total target. Now you can change this default by editing the DRM file.

A 2006.03 C-1

Draft 2/6/06

DRM File Format Raphael Tutorial

Typical DRM File

The following is a typical DRM file. The comments (starting with “//”) are added for tutorial purposes, and are not part of a normal DRM file. See the explanatory notes below for more details.

From a user standpoint, the heart of the file is the last 18 lines (starting with line 4). Those 18 lines form a table. The rows of the table are the 18 targets currently implemented. The columns of the table are the nine generic structures currently implemented. Table C-1 outlines the implemented generic structures and the asso-ciated numbers used in the DRM file.

Use the absolute model numbers in the table as the default for each target/struc-ture combination. Table C-2 and Table C-3 illustrate the absolute model numbers that correspond to the model names (both Standard Raphael models and user-defined models) in the DRM files. The equations that correspond to each of the standard Raphael models are described in Appendix B. To load a user-defined model from any convenient directory, specify it in the User-defined directory: field in the Location of user-defined equations: section of the Regression page in the User Preferences notebook. Refer to Chapter 5, Figure 5-3, p. 5-6 for fur-ther details.

Each entry (model number) in the table has a row/column position that corre-sponds to a target/structure combination.

Look at the second number in line 4 in the file (which is the first line in the table). The row is for target 0; the column is for structure 1; and the entry is “4”. Thus, model 4 (“Mono decreasing”) will be used for target 0 (C total) for generic struc-ture 1 (“Array between ground planes”).

DRM 0001 // Line 1: File info0 1 2 3 6 7 8 9 10 // Line 2: Structures0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 // Targets 4 4 19 19 4 4 4 4 4 20 20 // Target 0: C total14 14 19 19 14 14 4 4 4 20 20 // Target 1: C coupling 5 5 19 19 5 5 4 4 4 20 20 // Target 2: C top gp 5 5 19 19 5 5 4 4 4 20 20 // Target 3: C bottom gp 9 9 19 19 9 9 4 4 4 20 20 // Target 4: C top array total 9 9 19 19 9 9 4 4 4 20 20 // Target 5: C top array coupling 7 7 19 19 7 7 4 4 4 20 20 // Target 6: C top array top gp 4 4 4 4 4 4 4 4 4 20 20 // Target 7: C top array bottom gp10 10 19 19 10 10 4 4 4 20 20 // Target 8: C cross over 8 8 19 19 8 8 4 4 4 20 20 // Target 9: C bottom array total 8 8 19 19 8 8 4 4 4 20 20 // Target 10: C bottom array coupling 4 4 4 4 4 4 4 4 4 20 20 // Target 11: C bottom array top gp 6 6 19 19 6 6 4 4 4 20 20 // Target 12: C bottom array bottom gp10 10 19 19 10 10 4 4 4 20 20 // Target 13: C top bottom center coupling10 10 19 19 10 10 4 4 4 20 20 // Target 14: C top bottom cross coupling10 10 19 19 10 10 4 4 4 20 20 // Target 15: C top bottom cross coupling4 4 4 4 4 4 5 5 4 20 20 // Target 16: C coincident edge4 4 4 4 4 4 4 4 5 20 20 // Target 17: C top gp bottom gp

C-2 RA 2006.03

Draft 2/6/06

Raphael Tutorial DRM File Format

R

B. R

egressio

nA

nalaysis

C. R

egressio

n

Defau

lts

Table C-1: Generic Structures in Raphael

Generic Structure Number Generic Structure Name

0 Array above ground plane

1 Array between ground planes

2 Parallel arrays above ground plane

3 Parallel arrays between ground planes

6 Array cross above ground plane

7 Array cross between ground planes

8 Coincident edge above ground plane

9 Coincident edge between ground planes

10 Oversize structure between ground planes

11 Different-layer traces above ground plane

12 Different-layer traces between ground planes

Table C-2: Standard Raphael defined Models available for regression analysis

Model Number

Number of arrays

Model Name

4 1 “Mono decreasing”

5 1 “Mono increasing”

6 2 “Mono increasing (bottom array)”

7 2 “Mono increasing (top array)”

8 2 “Mono decreasing (bottom array)”

9 2 “Mono decreasing (top array)”

10 2 “Crossover”

11 2 “Parallel arrays”

12 2 “Parallel arrays (bottom-top cross coupling)”

14 1 “Coupling”

15 1 “Ref. (ground plane)”

16 1 “Ref. (coupling)”

17 2 “Ref. (crossover)”

A 2006.03 C-3

Draft 2/6/06

DRM File Format Raphael Tutorial

CAUTION Avoid mixing one-array models with two-array targets (and vice-versa); otherwise, Raphael may abort.

• Lines 1-3 should not be changed at all. Any changes will cause a read error.

• Line 1 contains the file type and version number.

• Line 2 contains the absolute generic structure numbers. These numbers label the columns in the table described in Table C-1.

• Line 3 contains the absolute target numbers. These numbers are described in Table C-4 through Table C-6 in the following section.

18 2 “Ref. (top-bottom cross coupling)”

19 2 “Rational (1)”

20 2 “Rational (2)”

Table C-3: User-defined Models available for regression analysis

Model Number

Number of arrays

Model Name

1000 1 “User defined Ia”

1001 1 “User defined Ib”

1002 1 “User defined Ic”

1003 1 “User defined Id”

2000 2 “User defined IIa

2001 2 “User defined IIb”

2002 2 “User defined IIc”

2003 2 “User defined IId”

2004 2 “User defined IIe”

2005 2 “User defined IIf”

2006 2 “User defined IIg”

2007 2 “User defined IIh”

Table C-2: Standard Raphael defined Models available for regression analysis

Model Number

Number of arrays

Model Name

C-4 RA 2006.03

Draft 2/6/06

Raphael Tutorial Default Regression Models

R

B. R

egressio

nA

nalaysis

C. R

egressio

n

Defau

lts

Default Regression ModelsThe following tables show the default selection of regression models.

Table C-4: Default regression models for one array generic structures

Target Number

Target NameArray above ground

planeArray between ground planes

0 C total “Mono decreasing” “Mono decreasing”

1 C coupling “Coupling” “Coupling”

2 C top gp “Mono increasing” “Mono increasing”

3 C bottom gp “Mono increasing” “Mono increasing”

16 C coincident edge “Mono increasing” “Mono increasing”

17 C top bottom gp “Mono increasing” “Mono increasing”

Table C-5: Default regression models for parallel array generic structures

Target Number

Target NameParallel arrays above ground

plane

Parallel arrays between ground

planes

4 C top array total “Rational (1)” “Rational (1)”

5 C top array coupling “Rational (1)” “Rational (1)”

6 C top array top gp “Rational (1)” “Rational (1)”

9 C bottom array total “Rational (1)” “Rational (1)”

10 C bottom array coupling “Rational (1)” “Rational (1)”

12 C bottom array bottom gp “Rational (1)” “Rational (1)”

13 C top bottom center coupling “Rational (1)” “Rational (1)”

14 C top bottom cross coupling “Rational (1)” “Rational (1)”

15 C bottom top cross coupling “Rational (1)” “Rational (1)”

Table C-6: Default regression models for two array cross over generic structures

Target Number

Target NameArray cross above ground

planeArray cross between ground

planes

4 C top array total “Mono decreasing (top array)” “Mono decreasing (top array)”

5 C top array coupling “Mono decreasing (top array)” “Mono decreasing (top array)”

6 C top array top gp “Mono increasing (top array)” “Mono increasing (top array)”

A 2006.03 C-5

Draft 2/6/06

Default Regression Models Raphael Tutorial

8 C crossover “Crossover” “Crossover”

9 C bottom array total “Mono decreasing (bottom array)” “Mono decreasing (bottom array)”

10 C bottom array coupling Mono decreasing (bottom array) Mono decreasing (bottom array)

12 C bottom array bottom gp “Mono increasing (bottom array)” “Mono increasing (bottom array)”

Table C-6: Default regression models for two array cross over generic structures

Target Number

Target NameArray cross above ground

planeArray cross between ground

planes

Table C-7: Default regression models for different layers generic structures

Target Number

Target NameParallel arrays above ground

plane

Parallel arrays between ground

planes

20 C top bottom coupling “Rational (2)” “Rational (2)”

C-6 RA 2006.03

Draft 2/6/06

APPENDIX D

R

Cap

acitance

C. R

egressio

n D

. Map

pin

g L

PE

Appendix D: Mapping Raphael Capacitance to LPE ModelsD

In order to transfer the field solver accuracy to such LPE tools as Dracula, Diva & Vampire, and xCalibre & ICextract, a mapping procedure is needed between the capacitance models used in Raphael and LPE tools. This appendix lists some equations used to map Raphael capacitance to LPE models. For the definitions of Raphael capacitances used in this appendix, refer to Appendix A.

Array Above a Ground Plane

Equation D-1

Equation D-2

Equation D-3

Where:

Cbottom gp, s w,( ) Ca w⋅ 2 Cp 2D, s w,( )⋅+=

Ccoupling s w,( ) Clateral s w,( ) s⁄= s 0≠

Ccoupling s w,( ) Clateral s w,( )= s 0=

Ca Parallel plate capacitance coefficient between trace and ground

Cp,2D 2D perimeter capacitance coefficient

Clateral Lateral coupling coefficient

A 2006.03 D-1

Draft 2/6/06

Array Between Ground Planes Raphael Tutorial

Array Between Ground Planes

Equation D-4

Equation D-5

Equation D-6

Equation D-7

Where:

Array Crossover Above a Ground PlaneEquation D-8

or

Equation D-9

Where:

Cbottom gp, s w,( ) Cab w⋅ 2 Csd 2D, s w,(⋅+=

Ctop gp, s w,( ) Cat w⋅ 2 Csu 2D, s w,( )⋅+=

Ccoupling s w,( ) Clateral s w,( ) s⁄= s 0≠

Ccoupling s w,( ) Clateral s w,( )= s 0=

Cab Parallel plate capacitance coefficient between trace and bottom ground plane

Cat Parallel plate capacitance coefficient between trace and top ground plane

Csd,2D 2D sidewall down capacitance coefficient

Csu,2D 2D sidewall up capacitance coefficient


rossover wb sb wt s, , t,( ) Ca wb wt⋅ ⋅ 2 Csd wb⋅ Csu w⋅+(Ca wb wt 2 factor Csd 2D, wb⋅ Csu 2D, w⋅+(⋅ ⋅+⋅ ⋅=

⋅+=

Ccrossover wb sb wt s, , t,( ) Ca wb wt⋅ ⋅ 2 Cp wb wt+( )⋅ ⋅+=

Ca Parallel plate capacitance between two traces

Csd Sidewall down capacitance coefficient, Csd = factor * Csd,2D

D-2 RA 2006.03

Draft 2/6/06

Raphael Tutorial Array Crossover Between Ground Planes

R

Cap

acitance

D. M

app

ing

LP

E

Array Crossover Between Ground PlanesEquation D-10

or

Equation D-11

Where:

Csu Sidewall up capacitance coefficient, Csu = factor * Csu,2D

Cp Equivalent perimeter capacitance coefficient which is the weighted average value of Csd and Csu.

Csd,2D 2D sidewall down capacitance coefficient obtained from the array above a ground plane structure by treating the bottom layer as a ground plane

Csu,2D 2D sidewall up capacitance coefficient obtained from the array between ground planes structure by treating the top layer as a ground plane

rossover wb sb wt s, , t,( ) Ca wb wt⋅ ⋅ 2 Csd wb⋅ Csu w⋅+(Ca wb wt 2 factor Csd 2D, wb⋅ Csu 2D, w⋅+(⋅ ⋅+⋅ ⋅=

⋅+=

Ccrossover wb sb wt s, , t,( ) Ca wb wt⋅ ⋅ 2 Cp wb wt+( )⋅ ⋅+=

Ca Parallel plate capacitance between two traces

Csd Sidewall down capacitance coefficient, Csd = factor * Csd,2D

Csu Sidewall up capacitance coefficient, Csu = factor * Csu,2D

Cp Equivalent perimeter capacitance coefficient which is the weighted average value of Csd and Csu

Csd,2D 2D sidewall down capacitance coefficient obtained from the array between ground planes structure by treating the bottom trace as a bottom ground plane

Csu,2D 2D sidewall up capacitance coefficient obtained from the array between ground planes structure by treating the top trace as a top ground plane

A 2006.03 D-3

Draft 2/6/06

Parallel Arrays Above a Ground Plane Raphael Tutorial

Parallel Arrays Above a Ground Plane

Equation D-12

Equation D-13

Where:

Parallel Arrays Between Ground Planes

Equation D-14

Equation D-15

Where:

Coincident Edge Above a Ground Plane

Equation D-16

Where:

Coincident Edge Between Ground Planes

Equation D-17

Where:

Ctbcc s w,( ) Clateral s w,( ) s⁄= s 0≠

Ctbcc s w,( ) Clateral s w,( )= s 0=





Ccoed s w,( ) Ca w⋅ 2 Cp coed, s w,(⋅+=

Ca Parallel plate capacitance coefficient between trace to ground

Cp,coed Coincident edge capacitance coefficient

Ccoed s w,( ) Ca w⋅ 2 Cp coed, s w,(⋅+=

Ca Parallel plate capacitance coefficient between trace to ground

Cp,coed Coincident edge capacitance coefficient

D-4 RA 2006.03

Draft 2/6/06

Raphael Tutorial Oversize Structure Between Ground Planes

Cap

acitance

D. M

app

ing

LP

E

Oversize Structure Between Ground Planes

Equation D-18

or

Equation D-19

Where:

Different Layers Above a Ground Plane

Equation D-20

Equation D-21

Where:

Different Layers Between Ground Planes

Equation D-22

Equation D-23

Where:

Ctgbg s w,( ) Ca 2 ΔCa s w,( )⋅+( ) s⋅=

Ctgbg s w,( ) Ca s 2 Δs s w,( )⋅+( )⋅=

Ca Parallel plate capacitance coefficient between two oversized structures (ground planes)

Correction (shielding) factor for the area capacitance coefficient for two oversized structures with a shielding conductor

Resizing factor for the area capacitance for two oversized struc-tures with a shielding conductor

ΔCa

Δs







RA 2006.03 D-5

Draft 2/6/06

Different Layers Between Ground Planes Raphael Tutorial
D-6 RA 2006.03
Draft 2/6/06

APPENDIX E

E. F

ield S

olver

Temp

lates

Appendix E: Field Solver TemplatesE

This appendix introduces the field solver templates that are used to generate the input files for the Raphael field solvers.

Included in these files are the design detail parameters of the structures to be sim-ulated. For each of the generic structures available in Raphael, there is a separate template file.

This appendix also describes the design and structural parameters and the numeri-cal options available with the templates. To help you generate your own templates, an example is provided at the end of the appendix.

Technology, Structural and Design ParametersSince the Raphael input syntax accepts symbolic variables, you can define param-eters for numerical values. These parameters allow you to define arbitrary struc-tures to be simulated using the field solver template files. For further details on how to set up your own parameters, refer to the Raphael Reference Manual.

The default field solver templates use parameters to define the technology details as well as structural and design information for the six generic structures available with Raphael.

Predefined parameters for all the generic structures are:

• Technology Parameters

• Structure Parameters

• Design Parameters

Technology Parameters

The technology parameters relate to the thickness of the layers (conductors and dielectrics) and dielectric constants of the dielectrics defined in the technology.

RA 2006.03 E-1

Draft 2/6/06

Technology, Structural and Design Parameters Raphael Tutorial

The conductor thickness is defined by “t<conductor number>.” For example: for Conductor 1 (the bottom-most conductor in the layer stack), the thickness is defined with the t1 parameter.

Similarly, the dielectric thickness is defined by “h<dielectric number>.” In Dielectric 1 (the bottom-most dielectric), the thickness is defined as h1.

The dielectric constant follows a similar rule of preceding the dielectric number with the “E” prefix. For example: the dielectric constant for Dielectric 4 will be defined as E4.

The following section of a typical input file describes the technology parameters available to you.

$ Technology parametersparamh1=5e-07; h2=1e-07; h3=1.3e-06; h4=1e-07; h5=2.2e-06; h6=1e-07; h7=1.5e-06; h8=6e-06; t1 = 4e-07; t2 = 8e-07; t3 = 1.2e-06; E1=3.9; E2=4; E3=3.9; E4=4; E5=3.9; E6=4; E7=3.9; E8=1;

Structure Parameters

Structure parameters refer to the variables available to define the structure you wish to simulate. Some of the parameters available for the generic structures differ from one another. Tables E-1 through E-3 list the predefined structure parameters.

Table E-1 Common structure parameters for both one-array and two-array structures

Name Description

structureThickness Total thickness of the structure

topGroundThicka

a. If the structure contains a top ground plane

Thickness of the top ground plane

bottomGroundThickb

b. If the structure has “substrate” as the bottom ground plane, then the value from the first conductor is used.

Thickness of the bottom ground plane

topGroundVertCa Vertical midpoint (center) of the top ground plane

bottomGroundVertCb Vertical midpoint (center) of the bottom ground plane

topGroundTopa Z coordinate of the top of the top ground plane

bottomGroundBotb Z coordinate of the bottom of the bottom ground plane

E-2 RA 2006.03

Draft 2/6/06

Raphael Tutorial Technology, Structural and Design Parameters

E. F

ield S

olver

Temp

lates

Table E-2 Structure Parameters specific to one-array generic structures (array above ground plane and array between ground plane)

Table E-3 Structure Parameters specific to two-array generic structures parallel array above/between ground plane(s) and array cross above/between ground plane(s))

Name Description

Yarraybase Vertical coordinate of the base of the conductor array

arraythick Thickness of the conductor array

Yarraycenter Vertical Mid point (center) of the conductor array

Xtotal Total size of the window in the x-direction (the simulation width is 0.5 * Xtotal using the symmetry property)

Ytotal • Top (Z coordinate) of the topmost dielectric (if there is no top ground plane)

• Top (Z coordinate) of the top ground plane (if there is a top ground plane)

Name Description

Yarray1base Vertical coordinate of the base of the bottom array ofconductors

array1Thick Thickness of the bottom array of conductors

Yarray2base Vertical coordinate of the base of the top array of conductors

array2Thick Thickness of the top array of conductors

Xtotal Total size of the window in the x-direction (the simulation width is 0.5 * Xtotal using the symmetry property)

Ytotala

a. Defined only for two-dimensional structures (e.g. parallel arrays above/betweenground plane(s))

In the 2D case:• Top (Z coordinate) of the topmost dielectric (if there is no

top ground plane)


In the 3D case:• Total size of the y-direction

Ztotalb

b. Defined only for three-dimensional structures (e.g. array cross above/betweenground plane(s)

• Top (Z coordinate) of the topmost dielectric (if there is no top ground plane)


RA 2006.03 E-3

Draft 2/6/06


Design Parameters

Design parameters mostly relate to the width and spacing of the conductors and the dielectrics used in the technology. The dielectric constants of each of the dielectrics that are in the vicinity of a conductor are also reported. This informa-tion is useful in generating trapezoidal structures.

Figures E-1 and E-2 illustrate the design parameters for a one array between two ground planes and a parallel array between two ground planes structures, respec-tively.

Figure E-1 Design parameters for a one array between ground planes

arrayspace

arraythick

arraywidth

0 Xmid Xtotal

topGroundThick

Dielectric 2

Dielectric 1

structure-

topGroundVertC

Yarraycenter

bottom,GroundVertC

topGroundTop

bottomGroundBot

Yarraybase

Ytotal,

E_bot_gnd_bot

E_bot_gnd_top

E_top_cond_bot

E_top_cond_top

E_top_gnd_bot

E_top_gnd_top

Thickness

Simulation Window

Bottom Ground Plane

Top Ground Plane

bottomGroundThick

E-4 RA 2006.03

Draft 2/6/06


E. F

ield S

olver

Temp

lates

Table E-4 Design Parameters for one-array structures

Figure E-2 Design parameters for a parallel array between ground planes

array2Thick

array2Width

0 Xmid Xtotal

Bottom Ground Plane

Top Ground Plane

Dielectric 2

Dielectric 1

structure-

topGroundVertC

Yarraycenter

bottom,GroundVertC

topGroundTop

bottomGroundBot

Yarray2Base

Ytotal,

E_bot_gnd_bot

E_bot_gnd_top

E_top_cond_bot

E_top_cond_top

E_top_gnd_bot

E_top_gnd_top

Thickness

Simulation Window

Dielectric 3

array1Thickarray1Space

array1Width

Yarray1BaseE_bot_cond_bot

E_bot_cond_top

topGroundThick

array2Space

bottomGroundThick

Name Description

arraywidth Width of the conductors in the array

arrayspace Spacing between two neighboring conductors in the array

E_bot_gnd_bota Dielectric constant of the dielectric adjacent to the bottom of the bottom ground plane

E_bot_gnd_topa Dielectric constant of the dielectric adjacent to the top of the bottom ground plane

E_top_cond_bot Dielectric constant of the dielectric adjacent to the bottom of the conductor traces

E_top_cond_top Dielectric constant of the dielectric adjacent to the top of the conductor traces

E_top_gnd_botb Dielectric constant of the dielectric adjacent to the bottom of the top ground plane

E_top_gnd_topb Dielectric constant of the dielectric adjacent to the top of the top ground plane

E_bot_gnd_conf_N Dielectric constant of the conformal dielectric layer that covers bottom ground plane in the case it is not a “sub-strate”. N means number of conformal layer starting from 1 (conformal layer adjacent to the top of ground plane).

RA 2006.03 E-5

Draft 2/6/06


Table E-5 Design Parameters for two array structures

H_bot_gnd_conf_N Thickness of the conformal dielectric layer that covers bot-tom ground plane in the case it is not a “substrate”. N means number of conformal layer starting from 1 (confor-mal layer adjacent to the top of ground plane).

E_top_cond_conf_N Dielectric constant of the conformal dielectric layer that covers traces. N means number of conformal layer start-ing from 1 (conformal layer adjacent to the traces).

T_top_cond_conf_N Thickness of the conformal dielectric layer that covers traces. N means number of conformal layer starting from 1 (conformal layer adjacent to the traces).

H_top_cond_conf_N Thickness of the conformal dielectric layer on top of the traces. N means number of conformal layer starting from 1 (conformal layer adjacent to the traces).

S_top_cond_conf_N Sidewall thickness of the conformal dielectric layer that covers traces. N means number of conformal layer start-ing from 1 (conformal layer adjacent to the traces).

a. This value is not reported if the bottom ground plane is “substrate.”

b. This value is not reported if the structure does not have a top ground plane (e.g.one array above substrate).

Name Description

array1Width Width of the conductors in the bottom array

array1Space Spacing between two neighboring conductors in the bot-tom array

array2Width Width of the conductors in the top array

array2Space Spacing between two neighboring conductors in the top array

E_bot_gnd_bota Dielectric constant of the dielectric adjacent to the bottom of the bottom ground plane

E_bot_gnd_topa Dielectric constant of the dielectric adjacent to the top of the bottom ground plane

E_bot_cond_bot Dielectric constant of the dielectric adjacent to the bottom of the bottom conductor

E_bot_cond_top Dielectric constant of the dielectric adjacent to the top of the bottom conductor

E_top_cond_bot Dielectric constant of the dielectric adjacent to the bottom of the top conductor

E_top_cond_top Dielectric constant of the dielectric adjacent to the top of the top conductor

E_top_gnd_botb Dielectric constant of the dielectric adjacent to the bottom of the top ground plane

Name Description

E-6 RA 2006.03

Draft 2/6/06


E. F

ield S

olver

Temp

lates

E_top_gnd_topb Dielectric constant of the dielectric adjacent to the top of the top ground plane

E_bot_gnd_conf_N Dielectric constant of the conformal dielectric layer that covers bottom ground plane in the case it is not a “sub-strate”. N means number of conformal layer starting from 1 (conformal layer adjacent to the top of ground plane).

H_bot_gnd_conf_N Thickness of the conformal dielectric layer that covers bottom ground plane in the case it is not a “substrate”. N means number of conformal layer starting from 1 (confor-mal layer adjacent to the top of ground plane).

E_top_cond_conf_N Dielectric constant of the conformal dielectric layer that covers traces from the top array. N means number of con-formal layer starting from 1 (conformal layer adjacent to the traces).

T_top_cond_conf_N Thickness of the conformal dielectric layer that covers traces from the top array. N means number of conformal layer starting from 1 (conformal layer adjacent to the traces).

H_top_cond_conf_N Thickness of the conformal dielectric layer on top of the traces from the top array. N means number of conformal layer starting from 1 (conformal layer adjacent to the traces).

S_top_cond_conf_N Sidewall thickness of the conformal dielectric layer that covers traces from the top array. N means number of con-formal layer starting from 1 (conformal layer adjacent to the traces).

E_bot_cond_conf_N Dielectric constant of the conformal dielectric layer that covers traces from the bottom array. N means number of conformal layer starting from 1 (conformal layer adjacent to the traces).

T_bot_cond_conf_N Thickness of the conformal dielectric layer that covers traces from the bottom array. N means number of confor-mal layer starting from 1 (conformal layer adjacent to the traces).

H_bot_cond_conf_N Thickness of the conformal dielectric layer on top of the traces from the bottom array. N means number of confor-mal layer starting from 1 (conformal layer adjacent to the traces).

S_bot_cond_conf_N Sidewall thickness of the conformal dielectric layer that covers traces from the bottom array. N means number of conformal layer starting from 1 (conformal layer adjacent to the traces).

a. This value is not reported if the bottom ground plane is “substrate.”

Name Description

RA 2006.03 E-7

Draft 2/6/06

Simulation Window Raphael Tutorial

Simulation WindowThe simulation window defines the window size set up for the entire structure.

To utilize the symmetry of the structures available through Raphael, you can choose a simulation window of one half or one quarter the size of the entire struc-ture. Set up the simulation window size by using the Window/Window3d com-mands available in Raphael syntax. See the Raphael Reference Manual.

Physical properties (such as the dielectric constant) of the simulation window can also be defined. You can utilize an appropriately-sized simulation window, the symmetry of the elements of the structure, as well as the bias applied to the ele-ments.

Note:The reflection boundary condition applies to all the edges of the simula-tion window. To reduce the effect of the reflection boundary condition, increase the size of the simulation window. This will assure that the edges of the window are farther from the simulated structures inside the window. (For further details see the Raphael Reference Manual.)

Option BlockThe option block in the template sets the values for the parameters that drive the calculation process. These options affect the field solvers performance parame-ters. The following section of a typical template file lists the option statements.

options unit = 1.0; max_regrid = 1;

In the above example, the value for unit sets the scaling factor for the simulated structures. Refer to the Raphael Reference Manual for available options and their definitions.

b. This value is not reported if the structure does not have a top ground plane (e.g.one array above substrate).

E-8 RA 2006.03

Draft 2/6/06

Raphael Tutorial Example of User-Defined Structure

E. F

ield S

olver

Temp

lates

Example of User-Defined StructureUse the field solver templates to define the arbitrary structures for simulation. You can load your own templates by setting the appropriate directory in the User-defined directory: field in the Simulation page of the User Preferences note-book as shown in Figure E-3. Refer to Chapter 5 for further details.

The default Raphael-defined templates for each of the six generic structures are located in the <RA_PATH>/rpd/ directory.

For example: the default template for array cross above ground plane structure is located at <RA_PATH>/rpd/arr_cross_above_gp directory.

An example of a trapezoidal structure is shown below as a guideline to help you prepare your own templates.

By using the predefined parameters, you can construct a trapezoidal conductor structure with conformal dielectrics. Use the technology, structure, and design parameters along with some derived parameters to define the structural details of the conductors. The dielectrics are defined. The template file for an array above ground plane generic structure is shown below for reference. Figure E-4 illustrates the final user-defined structure.

The field solver templates for the trapezoidal conductors with conformal dielec-trics are available for all the generic structures in the<RA_PATH>/rpd/technologies/trapezoid,rpd directory.

View the structure using DPLOT. Generate a .pot file after the input file (trape-zoid.rc2) is generated. The following command describes the procedure to view the structure. For further details, see the Raphael Reference Manual.

%raphael rc2 -i -x trapezoid.rc2

%dplot

DP>data file=trapezoid.rc2.potDP>PLOT.2DDP>STRUCTURE BOUND

$ RA_GS1 0004$ Copyright (C) 1995 by Technology Modeling Associates, Inc. (TMA)$$ Three Parallel Traces Above a Ground Plane (RPD Generic Structure #1)param Ntrace = 3; ratio = 0.1;

Figure E-3 User-defined directory

RA 2006.03 E-9

Draft 2/6/06

Example of User-Defined Structure Raphael Tutorial

$ Insert here: Technology, structure, and design parameters

$ Derived parametersparamspace = arrayspace + arraywidth;Xt = Ntrace*space - arrayspace;Xtotal = Xt + 3 * structureThickness;Xmid = 0.5*Xtotal;c3x = 0.5*Xtotal;c2x = c3x - space;

xdt = ratio*arraywidth;ydt = ratio*arraythick;xds = xdt*ydt/arraythick;

$ Insert here: Dielectric stack

$ Bottom ground planebox name = plane1; volt = 0.0;w = Xtotal; h = bottomGroundThick; cx = Xmid; cy = bottomGroundVertC;

$ Uncomment this block and set Ntrace = 5 if five traces are to be simulated.$ param $ tcx = c2x - space; $ xs = tcx - 0.5*arraywidth;$ xf = tcx + 0.5*arraywidth;$ ys = Yarraycenter - 0.5*arraythick;$ yf = Yarraycenter + 0.5*arraythick;

$ poly name = trace1d; diel = E_top_cond_bot; color=9;$ xs-xds,ys;$ xs+xdt,yf+ydt;$ xf-xdt,yf+ydt;$ xf+xds,ys;

$ poly name = trace1; volt = 0.0;$ xs,ys;$ xs+xdt,yf;$ xf-xdt,yf;$ xf,ys;$param tcx = c2x; xs = tcx - 0.5*arraywidth;xf = tcx + 0.5*arraywidth;ys = Yarraycenter - 0.5*arraythick;yf = Yarraycenter + 0.5*arraythick;

poly name = trace2d; diel = E_top_cond_bot; color=9;xs-xds,ys;xs+xdt,yf+ydt;xf-xdt,yf+ydt;xf+xds,ys;

poly name = trace2; volt = 0.0;xs,ys;xs+xdt,yf;xf-xdt,yf;xf,ys;$param tcx = c3x;

E-10 RA 2006.03

Draft 2/6/06

Raphael Tutorial Example of User-Defined Structure

E. F

ield S

olver

Temp

lates

xs = tcx - 0.5*arraywidth;xf = tcx + 0.5*arraywidth;ys = Yarraycenter - 0.5*arraythick;yf = Yarraycenter + 0.5*arraythick;

poly name = trace3d; diel = E_top_cond_bot; color=9;xs-xds,ys;xs+xdt,yf+ydt;xf-xdt,yf+ydt;xf+xds,ys;

poly name = trace3; volt=1.0;xs,ys;xs+xdt,yf;xf-xdt,yf;xf,ys;$

window diel=1.0; x1 = 0.0; y1 = bottomGroundBot; x2 = 0.5 * Xtotal; y2 = Ytotal+1.5*Xt;potentialoptions unit = 1.0; max_regrid=1;

Figure E-4 Final trapezoidal user-defined structure

arrayspace

arraythick

0 Xmid Xtotal

Bottom Ground Plane

Dielectric 1

E_bot_gnd_bot

E_bot_gnd_top

E_top_cond_bot

E_top_cond_top

ys

yf +ydtyf

xsxs-xds xs +xdt xf-xdt xf xf+xds

RA 2006.03 E-11

Draft 2/6/06

Example of User-Defined Structure Raphael Tutorial
E-12 RA 2006.03
Draft 2/6/06

APPENDIX F

R

F. Dracu

laE

xamp

le
Appendix F: Raphael/Dracula Interface ExampleF
The example in this appendix highlights the entire flow of parasitics extraction using Raphael. The process is divided into three major sections:

• Creating the parasitics simulation database

• Generating the LPE rule file with accurate parasitic capacitance coefficients by using the databases generated in the previous step

• Running Dracula LPE to obtain the capacitance matrix

The results obtained with the three-part process are compared to the three-dimen-sional field solver results in a separate section of this appendix.

Note:To run this example completely you need to be a licensed user of

• Raphael with LPE Dracula Interface

• Cadence Dracula LPE

• Taurus Layout

Files Required to Run ExampleFiles required to run this example include:

• sram.gds

• TEXT

• sram.rul

• sram.map

Access these files from the directory <RA_PATH>/examples/lpe/dracula.

A 2006.03 F-1

Draft 2/6/06

Files Required to Run Example Raphael Tutorial

The parasitics database used in this example is available as sram, rpd in the <RA_PATH>/rpd/technologies directory.

The example illustrations use an SRAM cell to step through each of the sections described above. Figure F-1 illustrates the layout, and Figure F-2 displays the 3D geometry of the SRAM cell. A GDS II stream of the SRAM cell is required to run this example to completion.

Figure F-1 SRAM cell layout

F-2 RA 2006.03

Draft 2/6/06

Raphael Tutorial Creating the Parasitics Database

F. Dracu

laE

xamp

le

Creating the Parasitics DatabaseThe Raphael Parasitics Database (RPD) module is used to generate the parasitics database.

Invoke the module by clicking the icon associated with the Parasitics Database & LPE Tools Interface panel in the Raphael main window. The parasit-ics database used with the SRAM cell example is available as sram, rpd in the <RA_PATH>/rpd/technologies directory.

Step 1: Specifying Technology Characteristics

The first step in generating the parasitics database with Raphael is to specify the technology details.

1. Specify the name of the database in the Raphael Parasitics Database win-dow. Enter the name in the New database name: field of the Database Names section of the window.

Figure F-3 illustrates this step.

2. To specify the conductor and dielectric parameters, click the Define... button in the Raphael Parasitics Database window to open the Technology Char-acteristics window.

Figure F-2 3D geometry of SRAM cell

RA 2006.03 F-3

Draft 2/6/06

Creating the Parasitics Database Raphael Tutorial

3. In the Technology Parameters panel of the Technology Characteristics window specify:

• Dielectric Thickness

• Dielectric Constant

• Conductor Thickness

• Location in the dielectric stack

4. In the Width and Spacing Parameters panel of the window, specify the spacing and width parameters.

See Chapter 4 for further details on the technology characteristics specification.

Figure F-4 illustrates the Technology Characteristics window for the SRAM cell, and Figure F-5 shows the stack of conductors and dielectrics in the technol-ogy.

Figure F-3 Raphael Parasitics Database window

F-4 RA 2006.03

Draft 2/6/06

Raphael Tutorial Creating the Parasitics Database

F. Dracu

laE

xamp

le

Figure F-4 Technology Characteristics window for SRAM example

Figure F-5 Stack of dielectrics and conductors for SRAM example

0

0.5

1.9diel_1

diel_0

5.8

4.2diel_2

diel_3

POLY

MET1

MET2

0.4

0.8

1.2

air

RA 2006.03 F-5

Draft 2/6/06

Generating the LPE File Raphael Tutorial

Step 2: Setting User Preferences

After setting the technology characteristics specifications, the next step is to set the preferences for structure selection and simulation. These operations are done in the User Preferences notebook.

To open the User Preferences notebook, in the Raphael Parasitics Database window menu bar, execute Options➔User Preferences. Refer toChapter 5 for full details on setting the user preferences. In the case of the SRAM cell, the default preferences are used in each of the Simulation and LPE Interface pages. For the Structures page, all structures are chosen to simulate.

Step 3: Generating the Parasitics Database

Once the user preferences are set, there are two ways to generate the databases: automatically or manually.

AutomaticGeneration

With the automatic method, you can first preview the structures recommended for simulation and then proceed with the simulation.

1. Return to the Raphael Parasitics Database window.

2. Preview and simulate the structures selected by clicking the Automatically Create... button.

This operation automatically simulates the selected structures (and optionally performs the regression analysis and writes the GRD file).

ManualGeneration

The manual selection of structures is not recommended because you need to have detailed knowledge of which structures Raphael uses to generate LPE models.

Generating the LPE FileThe second major part of the extraction process is the generation of the LPE rule deck with accurate parasitic capacitance coefficients. In order to achieve this goal, use the LPE Tools Interface module. Click the LPE Tools Interface... button in Panel 4 of the Raphael Parasitics Database window to invoke the Raphael-to-Dracula Interface module. Once the LPE Tools Interface window is open, select the Dracula item in the 1. LPE Tool Format menu.

Step 1: Mapping Dracula LPE Layers to Raphael Conductors

The layer names and the sequence in which they appear in the design (GDS II file) may not match the conductor names and the order in which they are stacked in the Raphael parasitics database. This information is mapped from the Raphael

F-6 RA 2006.03

Draft 2/6/06

Raphael Tutorial Generating the LPE File

F. Dracu

laE

xamp

le

parasitics database to the design layer specification by changing the entries shown in the LPE Tools Interface window, or loading the presaved mapping file.

To load the mapping file for the SRAM example, execute File➔Load Layer Info... in the LPE Tools Interface window menu bar. The sram.map file can be found in the <RA_PATH>/examples/lpe/dracula directory. The file is displayed below for reference.

File: sram.map

$ MAP FILEME2 1.6 1.8 2.4 2.8 ME1 0.8 2.6 0.6 2.6 POLY 0.8 0.9 0.6 2.6 BULK

Step 2: Setting the LPE Interface Options

To set the LPE interface option, execute Options➔Preferences in the LPE Tools Interface window menu bar. Set the LPE option on the General and Dracula pages as shown in Figures F-6 and F-7.

Step 3: Generating the Rule Decks with Capacitance Models

To generate the rule decks with capacitance models, click the Generate LPE File... button in the LPE Tools Interface window. The output terminal should appear within a few seconds. Save the content of this terminal to a file.

RA 2006.03 F-7

Draft 2/6/06


Figure F-6 General page setting of the LPE options for SRAM example

F-8 RA 2006.03

Draft 2/6/06


F. Dracu

laE

xamp

le

Step 4: Constructing the Complete Rule File

The saved file in the previous step can be modified to include some header infor-mation to complete the rule file. The complete example rule file, sram.rul, can be found in the <RA_PATH>/examples/lpe/dracula directory, and is included in Fig-ures F-8 through F-11 for reference.

Figure F-7 LPE options for SRAM example

RA 2006.03 F-9

Draft 2/6/06


;=======================================; Header information;======================================= *DESCRIPTIONmode = exec nowsystem = gds2scale = 0.2 micresolution = 0.2 mic;unit=capacitance,pfINDISK=sram.gdsPRIMARY = CELLOUTDISK=sram_cap.gdsGROUND-NODE=ABC;POWER-NODE=VDD;program-dir=/Dracula/Main/red/bin/*END *INPUT-LAYERndiff=1pdiff=2nwell=3poly=5 text = 25 attach polycont=6cont=7ME1=8 text=28 attach ME1via=9ME2=10 text=30 attach ME2pad=15 text=35 attach padsubstrate = BULK 63CONNECT-LAY=BULK SUB nsd psd poly ME1 ME2*END *OPERATION EDTEXT = TEXT NOT BULK NWELL SUBAND PDIFF NWELL pdevNOT NDIFF NWELL ndevAND NDIFF POLY ngateAND PDIFF POLY pgateOR ngate pgate gateNOT ndev ngate nsdNOT pdev pgate psdnot NDIFF ndev welltieNOT PDIFF pdev subtieOR nsd welltie ndifOR psd subtie pdifOR pdif ndif diffAND SUB BULK BLKCONconnect ME2 ME1 by VIAconnect ME1 poly by contconnect ME1 nsd by contconnect ME1 psd by contconnect SUB BULK by BLKCON;LINK BULK to ABC

Figure F-8 First part of sram.rul file

F-10 RA 2006.03

Draft 2/6/06


F. Dracu

laE

xamp

le

;=======================================; coefficient definition starts here;======================================= extractParasitic(( layers( BULK POLY ME1 ME2 )

;-----------------------------------------------------------; CONFIG 1: SIMPLE TWO/ONE-LAYER INTERACTION WITH ------; AN OPTIONAL BOTTOM GROUND PLANE USING ------; THE SUBSTRATE ------;----------------------------------------------------------- ;-------------------------------------; OVERLAP CAPACITANCE ----------------;------------------------------------- ; STRUCTURE: POLY with BULK as a bottom ground plane (C1) ; Cperimeter: arr_above_gp/POLY,above,substratecap( BULK POLY 0.06906 0.0457 lateral( POLY( 0.6 0.02309 ) ( 0.7 0.0253 ) ( 0.8 0.02752 ) ( 0.9 0.02942 )( 1 0.03132 ) ( 1.1 0.03297 ) ( 1.2 0.03461 ) ( 1.3 0.03547 )( 1.4 0.03633 ) ( 1.5 0.03741 ) ( 1.6 0.03849 ) ( 1.7 0.03942 )( 1.8 0.04035 ) ( 1.9 0.04115 ) ( 2 0.04196 ) ( 2.1 0.04266 )( 2.2 0.04336 ) ( 2.3 0.04398 ) ( 2.4 0.0446 ) ( 2.5 0.04515 )( 2.6 0.0457 ) ) ) ; STRUCTURE: ME1 with BULK as a bottom ground plane (C1) ; Cperimeter: arr_above_gp/MET1,above,substratecap( BULK ME1 0.01817 0.02166 lateral( ME1( 0.6 0.008428 ) ( 0.7 0.009241 ) ( 0.8 0.01005 ) ( 0.9 0.01084 )( 1 0.01162 ) ( 1.1 0.01237 ) ( 1.2 0.01312 ) ( 1.3 0.01379 )( 1.4 0.01446 ) ( 1.5 0.01513 ) ( 1.6 0.0158 ) ( 1.7 0.01644 )( 1.8 0.01708 ) ( 1.9 0.0177 ) ( 2 0.01831 ) ( 2.1 0.01889 )( 2.2 0.01947 ) ( 2.3 0.02003 ) ( 2.4 0.02059 ) ( 2.5 0.02112 )( 2.6 0.02166 ) ) ) ; STRUCTURE: ME2 with BULK as a bottom ground plane (C1) ; Cperimeter: arr_above_gp/MET2,above,substratecap( BULK ME2 0.008222 0.01159 lateral( ME2( 2.4 0.01036 ) ( 2.45 0.01052 ) ( 2.5 0.01069 ) ( 2.55 0.01085 )( 2.6 0.01101 ) ( 2.65 0.01117 ) ( 2.7 0.01133 ) ( 2.75 0.01146 )( 2.8 0.01159 ) ) )

Figure F-9 Second part of sram.rul file

RA 2006.03 F-11

Draft 2/6/06


; STRUCTURE: ME1 above POLY; with BULK as a bottom ground plane (C1) ; cap( ME1 POLY 0.03453 0.01079 0.02527 0.03639 ) ; Cperimeter: arr_cross_above_gp/MET1,POLY,substratecap( POLY ME1 0.03453 0.03568 lateral( ME1( 0.6 0.01958 ) ( 0.7 0.02048 ) ( 0.8 0.02138 ) ( 0.9 0.0224 )( 1 0.02342 ) ( 1.1 0.02439 ) ( 1.2 0.02536 ) ( 1.3 0.02628 )( 1.4 0.02721 ) ( 1.5 0.02809 ) ( 1.6 0.02897 ) ( 1.7 0.02981 )( 1.8 0.03065 ) ( 1.9 0.03145 ) ( 2 0.03225 ) ( 2.1 0.03302 )( 2.2 0.03378 ) ( 2.3 0.03451 ) ( 2.4 0.03524 ) ( 2.5 0.03546 )( 2.6 0.03568 ) ) ) ; STRUCTURE: ME2 above POLY; with BULK as a bottom ground plane (C1) ; cap( ME2 POLY 0.01046 0.002004 0.01053 0.02163 ) ; Cperimeter: arr_cross_above_gp/MET2,POLY,substratecap( POLY ME2 0.01046 0.01489 lateral( ME2( 2.4 0.01367 ) ( 2.45 0.01378 ) ( 2.5 0.01389 ) ( 2.55 0.01406 )( 2.6 0.01423 ) ( 2.65 0.0144 ) ( 2.7 0.01456 ) ( 2.75 0.01473 )( 2.8 0.01489 ) ) ) ; STRUCTURE: ME2 above ME1; with BULK as a bottom ground plane (C1) ; cap( ME2 ME1 0.02302 0.0104 0.02249 0.03519 )

;-------------------------------------; FRINGE CAPACITANCE -----------------;------------------------------------- ; STRUCTURE: POLY with BULK as a bottom ground plane (C1) ; Cfringe (SL): arr_above_gp/POLY,above,substratefringe ( POLY POLY( 0.6 0.02854 ) ( 0.7 0.029 ) ( 0.8 0.02947 ) ( 0.9 0.02973 )( 1 0.02999 ) ( 1.1 0.03013 ) ( 1.2 0.03027 ) ( 1.3 0.02947 )( 1.4 0.02867 ) ( 1.5 0.02847 ) ( 1.6 0.02828 ) ( 1.7 0.02805 )( 1.8 0.02783 ) )

Figure F-10 Third part of sram.rul file

F-12 RA 2006.03

Draft 2/6/06


F. Dracu

laE

xamp

le

; STRUCTURE: ME1 with BULK as a bottom ground plane (C1) ; Cfringe (SL): arr_above_gp/MET1,above,substratefringe ( ME1 ME1( 0.6 0.05542 ) ( 0.7 0.05765 ) ( 0.8 0.05989 ) ( 0.9 0.06173 )( 1 0.06356 ) ( 1.1 0.0651 ) ( 1.2 0.06664 ) ( 1.3 0.06724 )( 1.4 0.06785 ) ( 1.5 0.06876 ) ( 1.6 0.06966 ) ( 1.7 0.0704 )( 1.8 0.07113 ) )

; STRUCTURE: ME2 with BULK as a bottom ground plane (C1) ; Cfringe (SL): arr_above_gp/MET2,above,substratefringe ( ME2 ME2( 2.4 0.08684 ) ( 2.45 0.08702 ) ( 2.5 0.0872 ) ( 2.55 0.08736 )( 2.6 0.08753 ) ( 2.65 0.08767 ) ( 2.7 0.08781 ) ( 2.75 0.08746 )( 2.8 0.0871 ) )

; STRUCTURE: ME1 above POLY; with BULK as a bottom ground plane (C1) ; Cfringe (DL): diff_lyrs_above_gp/MET1,POLY,substratefringe ( POLY ME1( 0 0.03624 ) ( 0.15 0.004892 ) ( 0.3 0.008696 ) ( 0.45 0.01145 )( 0.6 0.01314 ) ( 0.7 0.01385 ) ( 0.8 0.01415 ) ( 0.9 0.01426 ) ) ; STRUCTURE: ME2 above POLY; with BULK as a bottom ground plane (C1) ; Cfringe (DL): diff_lyrs_above_gp/MET2,POLY,substratefringe ( POLY ME2( 0 0.01314 ) ( 0.15 0.001896 ) ( 0.3 0.003643 ) ( 0.45 0.005195 )( 0.6 0.006567 ) ( 0.7 0.007391 ) ( 0.8 0.008137 ) ( 0.9 0.008806 ) ) ; STRUCTURE: ME2 above ME1; with BULK as a bottom ground plane (C1) ; Cfringe (DL): diff_lyrs_above_gp/MET2,MET1,substratefringe ( ME1 ME2( 0 0.03674 ) ( 0.15 0.005127 ) ( 0.3 0.009484 ) ( 0.45 0.01307 )( 0.6 0.01587 ) ( 0.7 0.01735 ) ( 0.8 0.01849 ) ( 0.9 0.01943 ) ) )) ;=======================================; coefficient definition ends here;======================================= ; extraction commandLPESELECT[A] CAP OUTPUT SPICE*END

Figure F-11 Last part of sram.rul file

RA 2006.03 F-13

Draft 2/6/06

Running Dracula LPE Raphael Tutorial

Running Dracula LPE This section briefly describes the procedure to run Dracula LPE. For further details refer to Dracula LPE Users Manual available from Cadence Design Systems.

After the final LPE rule file is ready, the next step is to run Dracula LPE to gener-ate the capacitance matrix. In order to run Dracula with the SRAM cell example, the following files need to be present:

sram.gds (GDS II stream)

TEXT (Layer Labels file)

sram.rul (the final LPE rule file generated from the previous section)

All three files are available in the <RA_PATH>/examples/lpe/dracula directory.

To run Dracula LPE, you must install the software and be licensed to use it.

1. Type PDRACULA in the UNIX shell. If you are a licensed user of Dracula, an interactive mode of the software is invoked.

2. Enter /g sram.rul at the prompt (:/g sram .rul).

3. Enter /f at the prompt to generate a Dracula batch file.

4. Enter /a to abort or /q to leave the program.

5. Enter jxsub.com to submit the batch job to Dracula.

Once the extraction is complete, the results are stored in a file called SPICE.DAT. The file contains the SPICE models of the capacitances between the different nodes present in the SRAM cell. The file displayed in Figure F-12 is for your ref-erence. SPICE.DAT is also available in the <RA_PATH>/examples/lpe/dracula directory.

F-14 RA 2006.03

Draft 2/6/06

Raphael Tutorial Comparing with RC3 Results

R

F. Dracu

laE

xamp

le

Comparing with RC3 ResultsTo compare the results obtained from the above procedure with the complete three-dimensional field solver approach, the SRAM cell was simulated using the Raphael RC3 solver.

Step 1: Generating the Input File for RC3

To generate the input file for RC3:

• Load the GDS II stream file, sram.gds, into Taurus Layout, the interconnect layout interface tool available from Synopsys TCAD.

• Execute File➔Load GDS... to load sram.gds, in the Taurus Layout main win-dow menu bar.

• Select CELL to expand in the cell list.

Figure F-13 illustrates the SRAM cell following the load operation.

** CADENCE/LPE SPICE FILE : SPICE * DATE : 3-JUL-97************* CAPACITORS PARAMETERS FROM : 7CAPXMER*********.GLOBAL ABC GND VDD **.SUBCKT SPICE BIT NOT_BIT S_M1_0 S_M1_1 WORD **CC1 BIT ABC 4.16243E00CC2 NOT_BIT ABC 4.17098E00CC3 GND ABC 3.48487E00CC4 S_M1_1 ABC 6.94883E00CC5 S_M1_0 ABC 6.99397E00CC6 VDD ABC 2.56343E00CC7 WORD ABC 2.38947E00CC8 ABC ABC 1.29058E01**----- TOTAL # OF CAPS FOUND : 8*----- COMMENTED : 0*.ENDS

Figure F-12 SPICE.DAT file

A 2006.03 F-15

Draft 2/6/06

Comparing with RC3 Results Raphael Tutorial

• Choose the Structure mode from the Taurus Layout main window.

• Choose the Simulation Rectangle tool (shown below) and select the define simulation rectangle from the SRAM layout.

• A popup window prompts you to save the defined simulation rectangle to an RC3 input to a file. The file sram.rc3 in the <RA_PATH>/examples/lpe/dracula directory was obtained by this process.

For more detailed information on generating a RC3 input file from Taurus Lay-out, refer to the Taurus Layout Tutorial.

Step 2: Running the RC3 Field Solver

To submit the input file generated in the previous step for simulation, issue the fol-lowing command in the UNIX shell.

% raphael rc3 -o sram.rc3.out sram.rc3

Figure F-13 SRAM cell viewed in Taurus Layout

F-16 RA 2006.03

Draft 2/6/06

Raphael Tutorial Comparing with RC3 Results

R

F. Dracu

laE

xamp

le

The output file sram.rc3.out contains the extracted capacitance matrix.

The same command can be issued through the Field Solvers module inside the Raphael GUI. Refer to Chapter 11 for further details on using the Field Solvers module.

The diagonal elements of the capacitance matrix obtained in the output file can be compared with the SPICE models obtained following the Dracula run on the SRAM example. Refer to the column titled Raphael/ RC3 in Figure F-14 for the diagonal elements of the capacitance matrix.

Finally, the capacitances obtained from the three-dimensional field solver approach and the SPICE models from the Dracula LPE are compared in Figure F-14. The capacitance is also obtained using Raphael-NES and shown in the same figure for reference. All capacitances are in fF. The percent error shown in the last column is computed with respect to the results from Raphael-NES.

Figure F-14 Comparison of Dracula and full-3D Raphael RC3 and Raphael-NES capacitances (in fF) for a SRAM cell

NODE Raphael-NES Raphael RC3 Dracula (3D)

BIT 3.17 3.19 4.16 (+31%)

NOT_BIT 3.20 3.20 4.17 (+30%)

VDD 2.59 2.62 2.56 (-1%)

GND 2.92 2.92 3.48 (+19%)

S_M1_1 5.58 5.64 6.95 (+25%)

S_M1_0 5.50 5.63 6.99 (+27%)

WORD 2.09 2.08 2.39 (+14%)

A 2006.03 F-17

Draft 2/6/06

Comparing with RC3 Results Raphael Tutorial
F-18 RA 2006.03
Draft 2/6/06

APPENDIX G

R

F. Dracu

laE

xamp

le
Appendix G: Interconnect Technology Format (ITF) FileG
ITF FileInterconnect Technology Format (ITF) file is a process description file which con-tains the cross-sectional profile, conductor sheet resistances, via resistances, and design rule spacing information for each conducting layer.

The ITF format provides the framework for describing complicated cross-sec-tions, and the accuracy for both Raphael and Synopsys Star-RCXT GRD genera-tor.

ITF Process File

The ITF structure offers the flexibility to model processes that have physical char-acteristics such as:

• Conformal dielectrics

• Vertically overlapping conductors (local interconnect)

• Width dependent conductor resistance (cladding)

• Layer specific etch effects

• Dielectric air gaps

• Metal fill

This format was designed to specifically handle leading edge VDSM (very deep sub micron) process effects and is only available with the Star-RCXT option.

A 2006.03 G-1

Draft 2/6/06

ITF File Raphael Tutorial

Additionally, ITF provides more configurability for current technologies and it consolidates all process information into one source file.

Note:The ‘$’ character at the beginning of a line denotes a comment. All ITF keywords described below are required to be UPPER CASE.

TechnologyStatement

This statement offers you a way of tagging a process with some identifier which can be any word. No white space is allowed.

TECHNOLOGY = <process_technology_name>

The TECHNOLOGY statement is mandatory.

A background dielectric may be specified, which globally fills the cross-section with the material of the given dielectric constant to an infinite height. DIELEC-TRIC commands specified in the ITF Process Cross-Section locally override the global background dielectric.

BACKGROUND_ER = < float >

Note:This constant background dielectric extends to an infinite height, so it effectively replaces air as the operating medium for the chip.

The default for the background dielectric is 1.0, or air.

Process Cross-Section

This section of the ITF process file describes the cross-sectional profile of the pro-cess in a ordered list of conductor and dielectric layer definition statements. The order of the layers as listed in the ITF is the order that the layers appear in the physical cross-section; that is, the first layer described in the ITF is farthest from the substrate, while the final layer is closest to the substrate.

Statements defining via layers follow the process cross-section and are only defined relative to valid conducting layers.

The ITF cross-section layer spatial parameters are specified in a way that is con-sistent with the physical process; that is, layer-by-layer from the ground up. The lowest layer in any cross-section is always the SUBSTRATE, a reserved keyword referring to a special conductor whose top plane is at zero. The SUBSTRATE is never defined in the ITF file.

The heights of the conductors and dielectrics are determined exclusively by the order in which they are specified and by the thicknesses of the lower layers. When specifying a new conductor or dielectric, the bottom plane of that layer is exactly the top plane of the last dielectric unless a MEASURED_FROM statement is included to explicitly specify the location of the bottom plane. The last conductor or dielectric (the lowest physical layer) listed in the ITF is automatically measured

G-2 RA 2006.03

Draft 2/6/06

Raphael Tutorial ITF File

R

F. Dracu

laE

xamp

le

from the SUBSTRATE. A fully planar homogeneous process is the simplest to model; an example of the cross-section and ITF for this type of process can be found in Figure G-6.

The MEASURED_FROM statement provides the ability to customize the model to account for such process characteristics as conformal dielectrics, mixed conformal and planar dielectrics and co-vertical conductors. When used with a DIELEC-TRIC layer definition, the MEASURED_FROM keyword may refer to a lower dielectric or may have the value TOP_OF_CHIP. When used with a CONDUCTOR layer definition, the MEASURED_FROM keyword may only refer to a lower PLANAR dielectric.

Note:CONDUCTOR definitions may not be non-planar. They must always be MEASURED_FROM a planar dielectric.

Conformal Dielectrics

The TOP_OF_CHIP keyword facilitates the creation of conformal dielectrics. It creates the bottom plane from the layer(s) already present below the new layer and mimics the topology of the existing base (copies any existing non-planarities to the new layer, that has a conformal thickness). See Figure G-7 for an example of a process with a conformal dielectric layer.

To regain layer planarity once a conformal dielectric has been defined, it is neces-sary to take the following steps when defining the new planarized layer.

1. Use the MEASURED_FROM statement to reference a planar dielectric some-where lower in the process cross-section.

2. Adjust the thickness for the new layer so it is equal to its actual physical thick-ness plus the thickness of any layer on top of the MEASURED_FROM layer.

Co-Vertical Conductors

Star-RCXT supports conductors that vertically overlap (co-vertical). Figure G-3 and Figure G-6 illustrate ITF handling of co-vertical conductors, that may have unique thicknesses as in the case of local poly interconnect.

Cladding

A variable effective resistance for routing layers is described in one of two ways:

• A table containing a minimum of two (width, resistance) data points

• The cladding sidewall “thickness” along with an effective cladding resistance

A 2006.03 G-3

Draft 2/6/06


The cladding description is included in the CONDUCTOR definition. Only one of either RPSQ or EFFECTIVE_RPSQ_TABLE may be specified for a particular conductor.

The second method of describing the cladding layer uses the CLAD_THICKNESS and CLAD_RPSQ keywords. Using this method, the RPSQ for the CONDUCTOR must be specified. The CLAD_THICKNESS should be a positive thickness less than half of the CONDUCTOR width, WMIN.

See Figure G-1 for an example of a process with cladding. This example shows:

• The lower routing layer m1 using the table method of defining the cladding layer.

• The upper routing layer m2 using the distinct cladding layer description.

Dielectric Air Gaps

Air gaps in the surrounding dielectric are constructed as part of the CONDUCTOR definition with the AIR_GAP_HEIGHT, AIR_GAP_WMAX and AIR_GAP_SMAX keywords. The dimensions of the air gap are determined by these parameters and their relationship to the CONDUCTOR that they are associated.

The AIR_GAP_HEIGHT is a vertical height automatically centered between the top and bottom of the CONDUCTOR. The upper limit has the same thickness as the CONDUCTOR. The air gap width is equal to the CONDUCTOR spacing unless the spacing is greater than AIR_GAP_WMAX in which case the width is equal to AIR_GAP_WMAX. If the CONDUCTOR spacing exceeds the AIR_GAP_SMAX, the air gap disappears.

Figure G-1 Effective cladding thickness

CONDUCTOR

t

t

Legend

t = effective cladding thickness

G-4 RA 2006.03

Draft 2/6/06


R

F. Dracu

laE

xamp

le

Figure G-2 is an example of a process with dielectric air gaps.

Layer Etch

An adjustment for layer etch effects that cause the manufactured line width of a conductor to be different from its drawn width can be made in the ITF process file. The keyword ETCH may be specified as a part of any CONDUCTOR definition.

Both conductor sidewalls will retreat or expand by the number specified in the ETCH command, resulting in a net width difference of twice the ETCH value. A positive ETCH value shrinks the CONDUCTOR width, and a negative ETCH value increases the CONDUCTOR width.

Figure G-3 is an example of a process with layer etch.

Figure G-2 Process with dielectric air gaps

SMAX

WMAX

air

air

Legend

case1: S<WMAX && S<SMAX W = S

case2: S>WMAX && S<SMAX W = WMAX

case3: S>WMAX && S>SMAX W = D

CONDUCTOR

AIR

DIELECTRIC

Figure G-3 Process utilizing the layer etch adjustment

CONDUCTOR

ETCHETCH

MWDW

Legend

DW = drawn widthMW = modeled width

MW = DW - 2 *ETCH

A 2006.03 G-5

Draft 2/6/06


Metal Fill

Extracting layout databases containing metal fill objects can exponentially increase runtime and memory requirements to account for a relatively small effect. An approximation for the capacative effects that proximal floating metal objects can have on routed signals in the design can be made simply and effectively in the ITF file. Handling metal fill effects during grdgenxo is extremely beneficial because this one-time operation eliminates the need to extract layout databases containing millions of fill objects. In addition, ITF modeling of a process with metal fill produces more realistic parasitic capacitances than the regular extraction with a layout including fill. This is because the ITF characterization models capacitance is shielded by electrically floating objects. A normal extraction neces-sarily assumes that the fill objects are connected to ground, and thus produces a conservative result.

Capacitances are modeled as a function of the global metal density for each extracted conducting layer. As an optional argument in the CONDUCTOR defini-tion, metal coverage is specified in the ITF file with the FILL_RATIO command. When FILL_RATIO is specified for a layer, any empty space encountered during the extraction is modeled as though it were filled with floating metal of the same layer. When used by itself, the FILL_RATIO command only affects vertical capacitance because fill objects are only placed in areas where they will not gener-ate any significant lateral capacitance with their neighbors.Figure G-4 illustrates the FILL_RATIO command.

For process technologies that allow lateral crowding of signal nets by fill objects, the FILL_WIDTH and FILL_SPACING commands may be specified in addition

Figure G-4 FILL_RATIO command

M2

M3

CROSS SECTION

C =M1

M2FILL

C1 + C2

C1C2

C1

C2

G-6 RA 2006.03

Draft 2/6/06


R

F. Dracu

laE

xamp

le

G

to FILL_RATIO. FILL_WIDTH and FILL_SPACING are used to define the dimensions of modeled fill objects within any empty space in the design which are big enough to accommodate them. FILL_WIDTH is the width of the fill object. FILL_SPACING is the distance from a signal net to a fill object.

Usually, all three fill parameters are determined by the design rules for the process technology. Of course, the fill modeling parameters only apply to empty space. Figure G-5 is an example of a process with metal fill.

DIELECTRIC Statement

Figure G-5 FILL_SPACING and FILL_WIDTH command

M2

TOP VIEW

C =

M2FILL

C1 + C2

C1C2

d d = FILL_SPACINw = FILL_WIDTH

M2

C1 C2

w

DIELECTRIC <diel_name> { THICKNESS=<value>

[MEASURED_FROM=<layer> [SW_T=<value>] [TW_T=<value>] ]

ER=<value>

}

Where Represents Requirement

THICKNESS The dielectric thickness measured from the top of the dielectric layer below it. The reference point can be changed by setting the MEASURED_FROM property.

[compulsory]

A 2006.03 G-7

Draft 2/6/06


CONDUCTOR Statement

MEASURED_FROM This modifies the reference from which thickness is measured. The default is the dielectric layer immediately below it. The key word TOP_OF_CHIP denotes the top surface of the process stack consisting only of dielectric and conductor statements that lie below it.

[optional]

SW_T Denotes the sidewall thickness of a conformal layer. [optional]

TW_T Denotes the topwall thickness. [optional]

ER Dielectric constant of the layer. [compulsory]


CONDUCTOR <cond_name> { THICKNESS=<value>

[MEASURED_FROM=<layer>]

WMIN=<value>

SMIN=<value>

[RPSQ=< >| RHO=< >]| EFFECTIVE_RPSQ_TABLE= {(width,rpsq)}|

RPSQ=< > CLAD_RPSQ=< > [CLAD_THICKNESS=< >]

[ETCH=<value>]

[AIR_GAP_M =< >[AIR_GAP_SMAX=< >[AIR_GAP_WMAX=< >]

[FILL_RATIO = <value>

}[FILL_RATIO = < >][FILL_WIDTH = < > FILL_SPACING = < > ]


THICKNESS The conductor thickness measured from the top of the dielectric layer below it. The reference point can be changed by setting the MEASURED_FROM property.

[compulsory]

MEASURED_FROM Modifies the reference where thickness is measured. The default is the dielectric layer immediately below it.

[optional]

G-8 RA 2006.03

Draft 2/6/06


R

F. Dracu

laE

xamp

le

VIA Statement

WMIN Minimum width of a conductor on this layer. [compulsory]

SMIN Minimum spacing between two conductors on this layer. [compulsory]

RSPQ | RHO The resistive properties of CONDUCTOR layers can be specified in the following two ways, but only one specification method is required.

[optional]

RPSQ Resistance per square of the conducting layer. Units: ohms

RHO Bulk resistivity of the conducting layer. Units: ohms-micron

CLAD_THICKNESS Effective thickness of the cladding layer. [optional]

CLAD_RPSQ Effective resistance of the cladding layer. Units: ohms/square

[optional]

EFFECTIVE_RPSQ_TABLE

Minimum of two (width, resistance) data points describing variable conductor resistance. Units: ohms/square

[optional]

ETCH Absolute width adjustment for layer etch effects. [optional]

AIR_GAP_HEIGHT

Vertically centered height of an air gap between conductor pieces.

[optional]

AIR_GAP_SMAX Maximum conductor spacing where an air gap may exist.

[optional]

AIR_GAP_WMAX Maximum width of the air gap. [optional]

FILL_RATIO Global ratio of metal coverage to total die area [optional]

FILL_SPACING Average lateral space separating signal nets and metal fill objects [um]. Required if FILL_WIDTH is specified

[optional]

FILL_WIDTH Average size of metal fill objects [um]. Required if FILL_SPACING is specified

[optional]


VIA <via_name> { FROM=<layer>

TO=<layer>

[RHO=<val> | RPV=<val> AREA=<val>]

}

A 2006.03 G-9

Draft 2/6/06

ITF Examples Raphael Tutorial

ITF ExamplesIn this section, each process technology example page contains both an ITF file (top half of page) and a diagram of the process cross-section (bottom half).

The following examples show a:Fully Planar ProcessProcess with Conformal DielectricProcess with Gate PolyProcess with Local InterconnectProcess with Conductor CladdingProcess with Dielectric Air GapsProcess with Layer EtchProcess with Metal Fill


FROM The lower layer connected by the via [must be CONDUCTOR].

[compulsory]

TO The upper layer connected by the via. A via can only connect two layers. Thus diffusion contact must be separated from poly contacts. [They probably have different resistance values!!]

[compulsory]

RHO | RPV The resistive properties of the via layer must be specified. For via layers they can specified in the following ways. Only one specification method should be used.

[optional]

RHO Bulk resistivity of the via layer Units: ohm-micron.

RPV Resistance per default via. Units: ohms. If RPV is specified then AREA is compulsory.

AREA Area of default via. Units: square-microns.

G-10 RA 2006.03

Draft 2/6/06

Raphael Tutorial ITF Examples

F. Dracu

laE

xamp

le

Figure G-6 Fully Planar Process

POLY

0.2

0.725

1.2

0.125

0.375

SUBSTRATE

M1

3.4

M2

0.6

0.6

TOP

D3

D2

D1

D0

TECHNOLOGY = planar

DIELECTRIC top { THICKNESS=3.4 ER=3.9 }DIELECTRIC d3 { THICKNESS=0.2 ER=3.9 }CONDUCTOR m2 { THICKNESS=0.6 WMIN=0.5 SMIN=0.5 RPSQ=0.05 }DIELECTRIC d2 { THICKNESS=1.2 ER=3.9 }CONDUCTOR m1 { THICKNESS=0.6 WMIN=0.3 SMIN=0.3 RPSQ=0.05 }DIELECTRIC d1 { THICKNESS=0.725 ER=3.9 }CONDUCTOR poly { THICKNESS=0.125 WMIN=0.3 SMIN=0.3 RPSQ=10.0 }DIELECTRIC d0 { THICKNESS=0.375 ER=3.9 }

VIA sub_tie { FROM=SUBSTRATE TO=m1 AREA=0.25 RPV=5 }VIA poly_cont { FROM=poly TO=m1 AREA=0.25 RPV=4 }VIA via { FROM=m1 TO=m2 AREA=0.36 RPV=4 }

RA 2006.03 G-11

Draft 2/6/06


TECHNOLOGY = conformal

DIELECTRIC TOP { THICKNESS = 3.6 MEASURED_FROM = D2 ER = 3.9 } $ planarizationDIELECTRIC D3 { THICKNESS = 0.2 MEASURED_FROM = TOP_OF_CHIP SW_T = 0.15 TW_T = 0.18 ER = 5.9 } $ D3 conformal dielectricCONDUCTOR M2 { THICKNESS = 0.6 WMIN = 0.5 SMIN = 0.5 RPSQ = 0.05 }DIELECTRIC D2 { THICKNESS = 1.2 ER = 3.9 } CONDUCTOR M1 { THICKNESS = 0.6 WMIN = 0.3 SMIN = 0.3 RPSQ = 0.05 }DIELECTRIC D1 { THICKNESS = 0.725 ER = 3.9 }CONDUCTOR POLY { THICKNESS = 0.125 WMIN = 0.3 SMIN = 0.3 RPSQ = 10.0 }DIELECTRIC D0 { THICKNESS = 0.375 ER = 3.9 }

VIA DIFF_CONT { FROM=SUBSTRATE TO=M1 AREA=0.25 RPV=5 }VIA POLY_CONT { FROM=POLY TO=M1 AREA=0.25 RPV = 4 }VIA V1 { FROM=M1 TO=M2 AREA=0.36 RPV = 4 }

Figure G-7 Process with Conformal Dielectric

POLY

0.2

0.725

1.2

0.125

0.375

SUBSTRATE

M1

3.6

M2

0.6

0.180.15

TOP

D3

D2

D1

D0

G-12 RA 2006.03

Draft 2/6/06


F. Dracu

laE

xamp

le

$ process with differentiation of POLY and GATE

TECHNOLOGY = polygate

DIELECTRIC TOP { THICKNESS = 1.2 ER = 3.9 } CONDUCTOR M2 { THICKNESS = 0.4 WMIN = 0.5 SMIN = 0.5 RPSQ = 0.05 } DIELECTRIC D4 { THICKNESS = 0.7 ER = 3.9} CONDUCTOR M1 { THICKNESS = 0.4 WMIN = 0.4 SMIN = 0.4 RPSQ = 0.05 }DIELECTRIC D3 { THICKNESS = 0.5 ER = 3.9}CONDUCTOR POLY { THICKNESS = 0.2 WMIN = 0.3 SMIN = 0.3 RPSQ = 10.0 }DIELECTRIC D2 { THICKNESS = 0.1 ER = 3.9 } $ measured from TOXCONDUCTOR GATE { THICKNESS = 0.2 WMIN = 0.2 SMIN = 0.2 RPSQ = 8.0 }DIELECTRIC TOX { THICKNESS = 0.2 ER = 3.9 }

VIA DIFF_CONT { FROM=SUBSTRATE TO = M1 AREA=0.25 RPV=5 }VIA POLY_CONT { FROM=POLY TO = M1 AREA=0.25 RPV=4 }VIA V1 { FROM = M1 TO=M2 AREA=0.36 RPV=4 }

Figure G-8 Process with Gate Poly

POLYGATE 0.1

0.20.2

1.2

0.4

0.5

0.70.4

SUBSTRATE

M2

M1

TOP

D4

D3

D2

TOX 0.2

RA 2006.03 G-13

Draft 2/6/06


$ process containing local interconnect

TECHNOLOGY = polyli

DIELECTRIC TOP { THICKNESS = 1.2 ER = 3.9 } CONDUCTOR M2 { THICKNESS = 0.4 WMIN = 0.5 SMIN = 0.5 RPSQ = 0.05 } DIELECTRIC D4 { THICKNESS = 0.7 ER = 3.9 } $ thickness measured from D3CONDUCTOR M1 { THICKNESS = 0.4 WMIN = 0.4 SMIN = 0.4 RPSQ = 0.05 }DIELECTRIC D3 { THICKNESS = 0.6 ER = 3.9 } $ thickness measured from D21CONDUCTOR LI { THICKNESS = 0.3 WMIN = 0.4 SMIN = 0.4 RPSQ = 1} $ LI thickness measured from top of D21CONDUCTOR POLY { THICKNESS = 0.2 WMIN = 0.2 SMIN = 0.2 RPSQ = 10.0 } $ POLY thickness measured from top of D21DIELECTRIC D21 { THICKNESS = 0.2 ER = 3.9 }

VIA LI_SUB { FROM=SUBSTRATE TO=LI AREA=0.25 RPV=4 }VIA CONT { FROM=LI TO=M1 AREA=0.25 RPV=5 } VIA V1 { FROM=M1 TO=M2 AREA=0.25 RPV=4 }

Figure G-9 Process with Local Interconnect

POLY LI0.6

1.2

0.4

0.4

0.2 0.3

0.7

SUBSTRATE

M2

M1

TOP

D4

D3

D21 0.2

G-14 RA 2006.03

Draft 2/6/06


F. Dracu

laE

xamp

le

Figure G-10 Process with Conductor Cladding

POLY

0.2

0.725

1.2

0.125

0.375

SUBSTRATE

3.4

0.6

0.6

TOP

D3

D2

D1

D0

M2

M1

TECHNOLOGY = claddedDIELECTRIC top { THICKNESS=3.4 ER=3.9 }DIELECTRIC d3 { THICKNESS=0.2 ER=3.9 }CONDUCTOR m2 { THICKNESS=0.6WMIN=0.5SMIN=0.5RPSQ=0.05CLAD_THICKNESS=0.1CLAD_RPSQ=1.1 }DIELECTRIC d2 { THICKNESS=1.2 ER=3.9 }CONDUCTOR m1 { THICKNESS=0.6WMIN=0.3SMIN=0.3EFFECTIVE_RPSQ_TABLE { (0.3,0.08) (0.6,0.06) } }DIELECTRIC d1 { THICKNESS=0.725 ER=3.9 }CONDUCTOR poly { THICKNESS=0.125 WMIN=0.3 SMIN=0.3 RPSQ=10.0 }DIELECTRIC d0 { THICKNESS=0.375 ER=3.9 }


RA 2006.03 G-15

Draft 2/6/06


Figure G-11 Process with Dielectric Air Gaps

POLY

0.2

0.725

1.2

0.125

0.375

SUBSTRATE

AIR

3.4

M2 0.6

TOP

D3

D2

D1

D0

M1 M1

1.0

0.60.4

TECHNOLOGY = airgap

DIELECTRIC top { THICKNESS=3.4 ER=3.9 }DIELECTRIC d3 { THICKNESS=0.2 ER=3.9 }CONDUCTOR m2 { THICKNESS=0.6 WMIN=0.5 SMIN=0.5 RPSQ=0.05 }DIELECTRIC d2 { THICKNESS=1.2 ER=3.9 }CONDUCTOR m1 { THICKNESS=0.6WMIN=0.3SMIN=0.3RPSQ=0.05AIR_GAP_HEIGHT=0.4AIR_GAP_WMAX=1.0AIR_GAP_SMAX=2.0 }DIELECTRIC d1 { THICKNESS=0.725 ER=3.9 }CONDUCTOR poly { THICKNESS=0.125 WMIN=0.3 SMIN=0.3 RPSQ=10.0 }DIELECTRIC d0 { THICKNESS=0.375 ER=3.9 }


G-16 RA 2006.03

Draft 2/6/06


F. Dracu

laE

xamp

le

Figure G-12 Process with Layer Etch

POLY

0.2

0.725

1.2

0.125

0.375

SUBSTRATE

3.4

0.6

0.6

TOP

D3

D2

D1

D0

M2

M1

RA 2006.03 G-17

Draft 2/6/06


TECHNOLOGY = etch

DIELECTRIC top { THICKNESS=3.4 ER=3.9 }DIELECTRIC d3 { THICKNESS=0.2 ER=3.9 }CONDUCTOR m2 {THICKNESS=0.6WMIN=0.5SMIN=0.5RPSQ=0.05ETCH=0.1 }DIELECTRIC d2 { THICKNESS=1.2 ER=3.9 }CONDUCTOR m1 { THICKNESS=0.6 WMIN=0.3 SMIN=0.3 RPSQ=0.05 ETCH=0.05 }DIELECTRIC d1 { THICKNESS=0.725 ER=3.9 }CONDUCTOR poly { THICKNESS=0.125 WMIN=0.3 SMIN=0.3 RPSQ=10.0 }DIELECTRIC d0 { THICKNESS=0.375 ER=3.9 }


G-18 RA 2006.03

Draft 2/6/06


F. Dracu

laE

xamp

le

Figure G-13 Process with Metal Fill

POLY

0.2

0.725

1.2

0.125

0.375

SUBSTRATE

3.4

M2 0.6

TOP

D3

D2

D1

D0

M1

1.0

0.6M1FILL

TECHNOLOGY = metal_fill

DIELECTRIC TOP { THICKNESS=3.4 ER=3.9 }DIELECTRIC D3 { THICKNESS=0.2 ER=3.9 }CONDUCTOR M2 {

THICKNESS=0.6 WMIN=0.5 SMIN=0.5 RPSQ=0.05FILL_RATIO=0.3 }

DIELECTRIC D2 { THICKNESS=1.2 ER=3.9 }CONDUCTOR M1 {

THICKNESS=0.6 WMIN=0.3 SMIN=0.3 RPSQ=0.05FILL_RATIO=0.4 FILL_SPACING=1.0 FILL_WIDTH=2.0 }

DIELECTRIC D1 { THICKNESS=0.725 ER=3.9 }CONDUCTOR POLY{ THICKNESS=0.125 WMIN=0.3 SMIN=0.3 RPSQ=10.0 }DIELECTRIC D0 { THICKNESS=0.375 ER=3.9 }

VIA sub_tie { FROM=SUBSTRATE TO=M1 AREA=0.25 RPV=5 }VIA poly_cont { FROM=POLY TO=M1 AREA=0.25 RPV=4 }VIA via { FROM=M1 TO=M2 AREA=0.36 RPV=4 }

RA 2006.03 G-19

Draft 2/6/06

ITF Attributes Not Supported by Raphael Raphael Tutorial

ITF Attributes Not Supported by RaphaelCurrently, Raphael ignores certain attributes for the conductors and dielectrics described in the ITF File. The following description illustrates the attributes of the ITF file elements that are not handled by Raphael.

• Conductors that are local interconnects (e.g. LI and POLY layers) are considered as a single conductor with the vertical location and thick-ness corresponding to the topmostlayer among this set of conductors.

• Conformal conductors (e.g. conductors with MEASURED_FROM = TOP_OF_CHIP) are considered as regular conductors and the thick-ness of the conductor is measured from the dielectric below.

• The following attributes in the CONDUCTOR statement are currently not processed by Raphael: RPSQ, RHO, CLAD_SW_T, CLAD_SIDE_WALL_RPSQ, FILL_RATIO, FILL_WIDTH, FILL_SPACING , AIR_GAP_HEIGHT, AIR_GAP_WMAX, and AIR_GAP_SMAX.

• VIA statements are currently not processed by Raphael.

Examples of ITF Files can be found at <RA_PATH>/examples/itf_files directory.

G-20 RA 2006.03

Draft 2/6/06

APPENDIX H

R

F. Dracu

laE

xamp

le
Appendix H: TFT TemplatesH
This appendix introduces the field solver templates that describe interconnect structures inherent for TFT liquid crystal displays.

TFT TemplatesIn contrast to standard RPD templates, TFT templates allow you to characterize nonplanar interconnect structures without bottom ground plane. TFT templates are placed in directories rpd/TFT1, rpd/TFT2, rpd/TFT3, rpd/TFT4,and rpd/TFT5. You can load these templates by setting appropriate directory in the User-defined directory: field in the Simulation page of the User Preference note-book. See the following sections for a detailed description of each template library and corresponding usage limitations.

A 2006.03 H-1

Draft 2/6/06

TFT Templates Raphael Tutorial

TFT1

Figure H-1 illustrates the 2D structure of the template from TFT1 library. Only one generic RPD structure (different layers above a ground plane) is available for this library. Structure does not include bottom ground plane.

Figure H-1 Schematic cross-section of the 2D structure from TFT1 template.

Parameters WM1, WM2 and TM1, TM2 define the trace width and thickness for the top and bottom conductor layers. These parameters are specified in Technology Characteristic window in sections Technology Parameters and Width and Spacing Parameters. Names of the bottom and top conductor layers can be arbi-trary (M1 and M2 are chosen here only for the sake of definiteness). Width of the top and bottom traces varies automatically in accordance with the values specified in Width and Spacing Parameters section. Top width of the bottom trace W1

M1 is used to specify trapezoidal cross-section of the bottom trace and is defined as

W1M1 = WM1*(1-ratio_bot) - 2*shift_bot

where ratio_bot and shift_bot are the parameters, which can be defined through the command-line option in the Simulation page of the User Preference note-book. To specify these options, click the RC2 button and enter the options in the cell next to it. For the command-line option, use the following:

-P”ratio_bot=0.1;shift_bot=0.2”

or

-P”ratio_bot=0.1”

or

-P”shift_bot=0.2”

H-2 RA 2006.03

Draft 2/6/06

Raphael Tutorial TFT Templates

R

F. Dracu

laE

xamp

le

The default values for ratio_bot and shift_bot are equal to 0, and hence the default setting corresponds to rectangular cross-section of the traces. Parameter ratio_bot is in arbitrary units while shift_bot is in microns.Schematic cross-sec-tion of the 2D structure from TFT1 template.

Top conductor layer is always placed on the conformal layer and specified posi-tion of the top conductor layer, as it appears in Technology Parameters section, will not affect the results of simulations. As RPD requires that bottom position of the top conductor layer will be above the top position of the bottom conductor layer, you must specify the proper position of the top conductor layer in Technol-ogy Parameters section on the Technology Characteristics page.

Space S varies from the minimum spacing distance specified for the bottom con-ductor layer to the sum of maximum and minimum spacing distance

S=Smin(M1) + s

where s varies from 0 to Smax(M1). Space defines horizontal position of the top trace with respect to the bottom trace and the left corner of the bottom trace is used as the reference point.

RPD automatically generates the following sequence of s values: 0, Smin/2, Smin, Smin+dS, Smin+2dS, ...., Smax. Here, dS means parameter Step1 defined in section Width and Spacing Parameters for M1. Let Smin(M1) is defined as 1, Smax(M1) is defined as 5, and dS is defined as 2, then RPD will generate the fol-lowing set of s values: 0, 0.5, 1, 3, and 5. Real spacing set will be: 1, 1.5, 2, 4, 6 due to the shift on the value of Smin(M1).

Structure can contain arbitrary number of the planar dielectric layers and one con-formal layer, which covers bottom conductor layer. All parameters of dielectric layers are specified in Technology Parameters section as usual. HC1 specifies the thickness of the conformal dielectric layer. You can separately specify sidewall thickness and the thickness of the conformal dielectric on top of the conductor in Conf.SWThick and Conf.Thick columns of Technology Parameters section. HD1 defines thickness of the dielectric layer that is on the top of conformal dielec-tric layer and is defined in Technology Characteristics page in section Technol-ogy Parameters. You can specify arbitrary number of planar dielectric layers below conformal dielectric layer C1 and above first planar dielectric layer D1.

CAUTIONThe following limitations in usage of the TFT1 template library apply:

• Only one conformal layer is available for bottom conductor layer.

• RPD does not automatically check specified parameters and resulting shape of the structure.

• Only Capacitance Table is available as a result of RPD work.

• RPD does not provide predefined analytical expressions to fit simulation results.

A 2006.03 H-3

Draft 2/6/06


TFT2

Figure H-2 illustrates 2D structure of the template from TFT2 library. Only one generic RPD structure (different layers above a ground plane) is available for this library. Structure does not include bottom ground plane.

Figure H-2 Schematic cross-section of the 2D structure from TFT2 template.


M1 is used to specify trapezoidal cross-section of the bottom trace and is defined as


where ratio_bot and shift_bot are the parameters, which can be defined through the command-line option in the Simulation page of the User Preference note-book. To specify these options, click RC2 button and enter the options in the cell next to it. For the command-line option, use the following:


or


or


H-4 RA 2006.03

Draft 2/6/06


R

F. Dracu

laE

xamp

le

The default values for ratio_bot and shift_bot are equal to 0, and hence the default setting corresponds to rectangular cross-section of the traces. Parameter ratio_bot is in arbitrary units while shift_bot is in microns.

Top conductor layer is always placed on the conformal layer and specified posi-tion of the top conductor layer, as it appears in Technology Parameters section, will not affect the results of simulations. As RPD requires that bottom position of the top conductor layer will be above the top position of the bottom conductor layer, user will be responsible to specify the proper position of the top conductor layer in Technology Parameters section on the Technology Characteristics page.

Space S varies from the minimum spacing distance specified for the bottom con-ductor layer to the sum of maximum and minimum spacing distance

S=Smin(M1) + s

where s varies from 0 to Smax(M1). Space defines horizontal position of the top trace with respect to the bottom trace and the right corner of the bottom trace is used as the reference point.


Structure can contain arbitrary number of the planar dielectric layers and one con-formal layer, which covers bottom conductor layer. All parameters of dielectric layers are specified in Technology Parameters section as usual. HC1 specifies the thickness of the conformal dielectric layer. Sidewall thickness and the thickness of the conformal dielectric on top of the conductor can be specified separately in Conf.SWThick and Conf.Thick columns of Technology Parameters section. HD1 defines thickness of the dielectric layer that is on the top of conformal dielec-tric layer and is defined in Technology Characteristics page in section Technol-ogy Parameters. You can specify arbitrary number of planar dielectric layers below conformal dielectric layer C1 and above first planar dielectric layer D1.

CAUTIONThe following usage limitations of the TFT2 template library apply:





A 2006.03 H-5

Draft 2/6/06


TFT3


Figure H-3 Schematic cross-section of the 2D structure from TFT3 template

Parameters WM1, WM2 and TM1, TM2 define the trace width and thickness for the top and bottom conductor layers. These parameters are specified in Technology Characteristic window in sections Technology Parameters and Width and Spacing Parameters. Names of the bottom and top conductor layers can be arbi-trary (M1 and M2 are chosen here only for the sake of definiteness). Width of the top and bottom traces varies automatically in accordance with the values specified in Width and Spacing Parameters section.

Top width of the bottom trace W1M1 is used to specify trapezoidal cross-section of

the bottom trace and is defined as




or


or


H-6 RA 2006.03

Draft 2/6/06


R

F. Dracu

laE

xamp

le

The default values for ratio_bot and shift_bot are equal to 0, and hence the default setting corresponds to rectangular cross-section of the traces. Parameter ratio_bot is in arbitrary units while shift_bot is in microns.The shape of the top trace can be also adjusted to trapezoidal cross-section by using two parameters: ratio_top and shift_top specified through the command line option in the Simu-lation page of the User Preference notebook. Then the top width of the top trace will be defined as

W1M2 = WM2*(1-ratio_top) - 2*shift_top.

To specify these parameters, click RC2 button and enter the options in the cell next to it. For the command-line option, use the following:

-P”ratio_top=0.1;shift_top=0.2;”

or

-P”ratio_top=0.1;”

or

-P”shift_top=0.2;”

The default values for ratio_top and shift_top are equal to 0; hence, the default setting corresponds to rectangular cross-section of the traces. Parameter ratio_top is in arbitrary units while shift_top is in microns.

Top conductor layer is placed at the specified position, as it appears in Technol-ogy Parameters section on the Technology Characteristics page.

Space S varies from 0 to the maximum spacing distance specified for the bottom conductor layer and defines horizontal position of the top trace with respect to the bottom trace while the right corner of the bottom trace is used as reference point.

RPD automatically generates the following sequence of S values: 0, Smin/2, Smin, Smin+dS, Smin+2dS, ...., Smax. Here, dS means parameter Step1 defined in section Width and Spacing Parameters for M1. Let Smin(M1) is defined as 1, Smax(M1) is defined as 5, and dS is defined as 2, then RPD will generate the fol-lowing set of S values: 0, 0.5, 1, 3, and 5.

Structure can contain arbitrary number of the planar dielectric layers. All parame-ters of dielectric layers are specified in Technology Parameters section as usual.





A 2006.03 H-7

Draft 2/6/06


TFT4


Figure H-4 Schematic cross-section of the 2D structure from TFT4 template


M1 is used to specify trapezoidal cross-section of the bottom trace and is defined as:


where ratio_bot and shift_bot are the parameters, which can be defined through the command line option in the Simulation page of the User Preference note-book. To specify these options, click RC2 button and enter the options in the cell next to it. For the command-line option, use the following:


or


or


H-8 RA 2006.03

Draft 2/6/06


R

F. Dracu

laE

xamp

le

The default values for ratio_bot and shift_bot are equal to 0, and hence the default setting corresponds to rectangular cross-section of the traces. Parameter ratio_bot is in arbitrary units while shift_bot is in microns.

The shape of the top trace can be also adjusted to trapezoidal cross-section by using two parameters: ratio_top and shift_top specified through the command-line option in the Simulation page of the User Preference notebook. Then the top width of the top trace will be defined as:


To specify these parameters user has to click RC2 button and enter the options in the cell next to it. For the command-line option, use the following:

-P”ratio_top=0.1;shift_top=0.2”

or


or

-P”shift_top=0.2”

The default values for ratio_top and shift_top are equal to 0, and hence the default setting corresponds to rectangular cross-section of the traces. Parameter ratio_top is in arbitrary units while shift_top is in microns.

Top conductor layer is always placed on the conformal layer and specified posi-tion of the top conductor layer, as it appears in Technology Parameters section, will not affect the results of simulations. As RPD requires that bottom position of the top conductor layer will be above the top position of the bottom conductor layer, you must specify the proper position of the top conductor layer in Technol-ogy Parameters section on the Technology Characteristics page.

Space S varies from the minimum spacing distance specified for the bottom con-ductor layer to the sum of maximum and minimum spacing distance:

S=Smin(M1) + s

where s varies from 0 to Smax(M1). Space defines horizontal position of the top trace with respect to the bottom trace and the right corner of the bottom trace is used as the reference point.


Structure can contain arbitrary number of the planar dielectric layers and one con-formal layer, which covers bottom conductor layer. All parameters of dielectric

A 2006.03 H-9

Draft 2/6/06


layers are specified in Technology Parameters section as usual. HC1 specifies the thickness of the conformal dielectric layer. Sidewall thickness and the thickness of the conformal dielectric on top of the conductor can be specified separately in Conf.SWThick and Conf.Thick columns of Technology Parameters section. HD1 defines thickness of the dielectric layer that is on the top of conformal dielec-tric layer and is defined in Technology Characteristics page in section Technol-ogy Parameters. Your can specify arbitrary number of planar dielectric layers below conformal dielectric layer C1 and above first planar dielectric layer D1.






H-10 RA 2006.03

Draft 2/6/06


R

F. Dracu

laE

xamp

le

TFT5


Figure H-5 Schematic cross-sections of the 2D structures from TFT5 template

Parameters WM1, WM2 and TM1 define the trace width and thickness for the bot-tom conductor layer. These parameters are specified in Technology Characteris-tic window in sections Technology Parameters and Width and Spacing Parameters. RPD recognizes structures only with equal trace width from the same conductor layer. To overcome this limitation current template allows to spec-ify different width of the left and right traces by defining two different conductor layers. Parameters for the left trace are from the bottom conductor layer and the parameters for the right trace are from the top conductor layer excepting thickness of the traces. Names of the bottom and top conductor layers can be arbitrary (M1 and M2 are chosen here only for the sake of definiteness). Width of the left and right traces varies automatically in accordance with the values specified in Width and Spacing Parameters section.

A 2006.03 H-11

Draft 2/6/06


Top width of the left trace W1M1 is used to specify trapezoidal cross-section of the

bottom trace and is defined as:



-P”ratio_bot=0.1;shift_bot=0.2;”

or


or


The default values for ratio_bot and shift_bot are equal to 0, and hence the default setting corresponds to rectangular cross-section of the traces. Parameter ratio_bot is in arbitrary units while shift_bot is in microns. The shape of the right trace can be also adjusted to trapezoidal cross-section by using two parameters: ratio_top and shift_top specified through the command-line option in the Simu-lation page of the User Preference notebook. Then the top width of the top trace will be defined as:


To specify these parameters, click RC2 button and enter the options in the cell next to it. For the command-line option, use the following:

-P”ratio_top=0.1;shift_top=0.2”

or


or

-P”shift_top=0.2”

The default values for ratio_top and shift_top are equal to 0, and hence the default setting corresponds to rectangular cross-section of the traces. Parameter ratio_top is in arbitrary units while shift_top is in microns.

Conductor layer, which is defined as a top conductor layer, is always placed in the same vertical position as the bottom conductor layer and its position, as it appears in Technology Parameters section, will not affect the results of simulations. As RPD requires that bottom position of the top conductor layer will be above the top position of the bottom conductor layer, you must specify the proper position of the

H-12 RA 2006.03

Draft 2/6/06


R

F. Dracu

laE

xamp

le

top conductor layer in Technology Parameters section on the Technology Char-acteristics page.

Space S varies from the minimum spacing distance specified for the bottom con-ductor layer to the sum of maximum and minimum spacing distance:

S=Smin(M1) + s

where s varies from 0 to Smax(M1).


Structure can contain arbitrary number of the planar dielectric layers and one con-formal layer, which covers bottom conductor layer, or only planar dielectric lay-ers. All parameters of dielectric layers are specified in Technology Parameters section as usual. HC1 specifies the thickness of the conformal dielectric layer. Sidewall thickness and the thickness of the conformal dielectric on top of the con-ductor can be specified separately in Conf.SWThick and Conf.Thick columns of Technology Parameters section. HD1 defines thickness of the dielectric layer that is on the top of conformal dielectric layer and is defined in Technology Charac-teristics page in section Technology Parameters. You can specify arbitrary num-ber of planar dielectric layers below conformal dielectric layer C1 and above first planar dielectric layer D1.






A 2006.03 H-13

Draft 2/6/06

H-14 RA 2006.03
Draft 2/6/06

GLOSSARY

Glo

ssary

Glossary

Glossary-9

This glossary contains terms frequently used in the Raphael Graphical User Interface Tutorial. A list of acronyms is included as the last section in the Glossary. For references to more information about a term, see the Index.

Aarea capacitance Area component of overlap capacitance (See overlap capacitance)

actual structures Generic structure with specific metal layer assignment (See generic structures)

BBoundary Element

Method (BEM)Numerical technique for solving electromagnetic problems based on integral equations

Ccapacitance table Table containing various capacitance values with respect to design parameters (width and

spacing)

Chern’s model Empirical capacitance model developed by J. H. Chern and others.

coincident edgecapacitance

Special case of perimeter capacitance for two coincident polygon edges (See perimeter capacitance)

CROSSOVERcapacitance

Term used in xCalibre and ICextract to denote the overlap capacitance between two metal layers

RA 2006.03 Glossary-1

Draft 2/6/06

Glossary Raphael Tutorial

G

DDiva LPE tool from Cadence (See Layout Parameter Extractor)

Dracula LPE tool from Cadence (See Layout Parameter Extractor)

Ffield simulation Solving partial differential equations for field quantities such as electric fields, voltages,

current densities, or charge densities.

field solver templates Template file for the input file of a field solver containing geometry information of generic structures

Finite-Difference (FD)method

Numerical technique for solving electromagnetic problems based on the finite difference approximation

fringing fields Fields generated by discontinuities in interconnects

GGDS II Popular binary file format for integrated circuit layouts

generic structures Predefined structures used to generate capacitance models (See actual structures)

IICextract LPE tool from Mentor Graphics (See Layout Parameter Extractor)

interconnect library Library containing common interconnect parasitic structures such as bends, vias, and crossovers

INTRINSICcapacitance

Term used in xCalibre and ICextract to denote the overlap capacitance between a metal layer and ground plane

LLayout Parameter

ExtractorCAD tool to extract circuit netlist (circuit simulator input file) from layouts

lateral couplingcapacitance

Capacitance between two lateral metals that do not overlap vertically

lossary-2 RA 2006.03

Draft 2/6/06

Raphael Tutorial Glossary

R

Glo

ssary

Nnonplanar technology Process technology that results in nonplanar structures

NEARBODYcapacitance

Term used in xCalibre and ICextract to denote the lateral coupling capacitance

Ooverlap capacitance Capacitance between two vertically overlapping metals, Overlap capacitance is the sum of

the area and perimeter capacitances. (See area capacitance and perimeter capacitance)

Pparasitics Nondevice circuit elements such as interconnects

perimeter capacitance Fringing field component of overlap capacitance (See overlap capacitance)

QQuickCAP An extremely fast field solver, available through Raphael-NES, to compute 3D capaci-

tances in large structures.

rule deck LPE input file containing design checking rules and capacitance models

SSakurai’s model Empirical capacitance model developed by T. Sakurai and K. Tamaru

sidewall-downcapacitance

Special case of perimeter capacitance for polygon edges located above a plane (See perim-eter capacitance)

sidewall-upcapacitance

Special case of perimeter capacitance for polygon edges located below a plane (See perim-eter capacitance)

TTCAD Technology Computer-Aided Design tools that solve partial differential equations to simu-

late semiconductor process, device, and interconnects

technologycharacteristics

Interconnect process parameters such as dielectric thickness and height, and metal thick-ness and height

A 2006.03 Glossary-3

Draft 2/6/06

Glossary Raphael Tutorial

G

templates See field solver templates

VVampire LPE tool from Cadence (See Layout Parameter Extractor)

XxCalibre LPE tool from Mentor Graphics (See Layout Parameter Extractor)

AcronymsBEM Boundary Element Method

FD Finite-Difference (Method)

LPE Layout Parameter Extractor

SPICE Simulation Program with Integrated Circuit Emphasis

TCAD Technology Computer-Aided Design

lossary-4 RA 2006.03

Draft 2/6/06

INDEX

R

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Ind

ex

Index
2D
models 9-6resistance and capacitance solvers 11-1

2x2 SRAM array 10-20

3D

geometry of SRAM cell Fig. F-3models (from crossover structures) 9-6view of SRAM cell Fig. 8-19, 9-18, 10-21

Aactual structures 6-9

additional command line options 5-5

additional data points 8-18

additional overlap capacitance model for Figure 13-5 using xCalibre and ICextract syntax Fig. 10-15

advanced equations 10-15

alternating 2D and 3D models 9-6

append summary to output option 11-3

applying preference settings 5-3

area capacitance 8-2, 9-2, 10-2

array

above ground plane model D-1between ground planes model D-2crossover above ground plane model D-2crossover between ground planes model D-3parallel, above ground plane model D-4parallel, between ground planes model D-4

As a function of lateral spacing button, LPE Interface Options window 9-14

automatic

copying/pasting 3-4, 3-11database creation 3-5generation F-6reset range values 10-4

Automatically Create button 3-5

Automatically Create pop-up window Fig. 3-6

avoiding generating excessive combinations 4-9

Bbasic equations, xCalibre 10-15

basic overlap capacitance model for Figure 13-5 using xCalibre and ICextract syntax Fig. 10-14

batch regression analysis 7-9

information output during batch regression 7-9marking a model 7-11targets 7-10

batch vs. manual regression 7-2

building a parasitics database 2-1

buttons

Adjacent layers only 10-13All layers 10-13Automatically Create 3-5Capacitance Tables... 3-7Create Database 7-15Define... 3-5, 4-1Generate LPE File 8-4, 9-4, 10-5LPE Tools Interface 8-1, 9-1Modeled as effective top/bottom ground

planes 10-12operations 8-18Parasitics Database & LPE Tools Interface

10-1Planarized Technology 4-10RIL... 1-4Setup 4-2

Ccancelling or restoring parameters 4-7

Cap vs Space tool 6-12, 7-20

Cap vs Width tool 6-12, 7-20

capacitance

A 2006.03 Index-1

Draft 2/6/06

Index Raphael Tutorial

I

different-layer lateral coupling 8-2, 9-2, 10-2lateral G-6multiple model definition 10-13parasitic
realistic G-6same-layer lateral coupling 8-2, 9-2, 10-2terms and definitions A-1vertical overlap G-6

capacitance model

Dracula syntax 8-13Fig. 8-12, 9-12, 10-13

Capacitance Tables... button 3-7

capacitance terminology

LPE Tools Interface 8-2, 9-2, 10-2LPE Tools Interface Fig. 8-3, 8-16, 9-3, 9-14,

10-3capacitance terms

array above a ground plane generic structure Fig. A-2

array between ground planes generic structure Fig. A-2

array crossover above a ground plane generic structure Fig. A-3

array crossover between ground planes generic structure Fig. A-4

coincident edge structure above a ground plane generic structure Fig. A-7

coincident edge structure between two ground planes generic structure Fig. A-7

different layers above a ground plane generic structure Fig. A-8

different layers between two ground planes generic structure Fig. A-9

oversize structure between two ground planes generic structure Fig. A-8

parallel array above/between ground planes A-1two parallel arrays above a ground plane generic

structure Fig. A-5two parallel arrays between two ground planes

generic structure Fig. A-6capacitance to ground plot 7-21

Capacitance vs. Width and Spacing Tools

overview 7-20Visualization window 7-21visualizing results 7-20

changing layer information 9-3

check input syntax only option 11-1, 11-7

choosing database names 5-1

cladding G-3

coincident edge 9-2, 10-2

above ground plane model D-4between ground planes model D-4components 9-14perimeter capacitance 8-2

comparison of Diva and full-3D (Raphael NES) capacitances (in fF)

2x2 SRAM array Fig. 9-21single SRAM cell Fig. 9-20

comparison of Dracula and full-3D Raphael NES capacitances (in fF)


comparison of Dracula and full-3D Raphael RC3 and Raphael NES capacitances (in fF) for a SRAM cell Fig. F-17

comparison of xCalibre and full-3D (Raphael NES) capacitances (in fF)


CONDUCTOR

definition G-6conductor

positioning 4-6thickness E-2

conformal dielectric specification

example 1 4-4example 2 4-4example 3 4-5

conformal dielectrics G-3

conformal dielectrics specification 4-7

constant value format 8-14

constructing the complete rule file F-9

conventions

typographical 1-xiiicopying and pasting technology characteristics 3-10, 4-2

coupling capacitance

beyond adjacent layer Fig. 8-10beyond nearest neighboring conductors Fig. 8-10,

9-10, 10-11beyond the adjacent layer Fig. 10-11vs. space plot 7-21

co-vertical conductors G-3

Create Database button 7-15

Create/Inspect Parasitics Database window 7-15, 7-20

Create/Inspect Parasitics Database window structures for sram database Fig. 6-9

creating parasitics database 3-1 to 3-12, F-3

generating capacitance tables 3-7

ndex-2 RA 2006.03

Draft 2/6/06

Raphael Tutorial Index


Ind

ex

invoking LPE Tools Interface 3-7menu bar 3-9Options menu for User Preferences notebook

3-12overview 3-1Raphael Parasitics Database window 3-1simulation and regression 3-5

crossover

default finite difference solver 5-5overlap 8-8, 9-7, 10-7

crossover capacitance

model using advanced equations of xCalibre and ICextract Fig. 10-17

model using default equations of xCalibre and ICextract Fig. 10-16

Ddatabase

deletion 3-9directory 3-3directory, environment variable 3-4frozen 4-3, 4-17parasitics 7-20, F-2preferences 9-4, 10-4

Database Names panel, Raphael Parasitics Database window 3-2

Default Regression Models see DRM

Define... button 3-5, 4-1

defining technology characteristics 3-5

design parameters E-1, E-4

editing 4-9one array between ground planes Fig. E-4parallel array between ground planes Fig. E-5

diagonal elements F-17

dielectric

constants E-2, E-4layers positioning 4-3thickness E-2

dielectric air gaps G-4

different layers

above a ground plane generic structure Fig. 6-5above ground plane model D-5between ground planes model D-5

different-layer lateral coupling capacitance 8-2, 9-2, 10-2

dimension, modeled fill object G-7

directory, existing 3-4

Diva & Vampire page

LPE Tools Interface Options window 9-11LPE Tools Interface Options window Fig. 9-11

Diva and Vampire LPE Interface 9-3

capacitance model 9-12changing layer information (optional) 9-3generating rule file 9-4selecting the target LPE format 9-3specifying options (optional) 9-4

Dracula

LPE interface example F-1Output Terminal window Fig. 8-5overview 8-1syntax 8-15using 8-3

Dracula page

LPE options for SRAM example F-9LPE Tools Interface Options window 8-11LPE Tools Interface Options window Fig. 8-11setting for SRAM example Fig. 8-21

DRM

files 5-7, C-1overview C-1recommended models C-5

EEdit menu 4-17, 6-12

Edit-Deletenot reversible 6-12pop-up window Fig. 3-9selected database 3-9time 3-9, 6-13

effective cladding thickness Fig. G-4

equations

regression analysis model definitions B-1exporting and importing LPE Tools Interface

Options 8-18

exporting generic structures to create actual structures 6-7

extract

layoutdatabase, metal fill G-6

Extract vs. Fix 7-5

extractParasitic command 8-18

FField Solver Templates

RA 2006.03 Index-3

Draft 2/6/06


I

option block E-8overview E-1parameters E-1simulation window E-8structure example E-9
field solvers

R13 11-1RC2 11-1RC2-BEM 11-1RC3 11-1RC3-BEM 11-1templates E-1, H-1

Field Solvers module 1-4

fields, New database name 3-4

file disc.pts. 4-9

File menu 4-17, 6-12

File menu in LPE Tools Options window Fig. 8-18

File operations for conductor layer information Fig. 8-4, 9-4, 10-4

files required to run Raphael/Dracula Interface example F-1

fill object

define dimension G-7metal G-6

FILL_RATIO G-6, G-7

FILL_SPACING G-6

FILL_WIDTH G-6

fine and course variation in spacing parameters for Ranges 1 and 2 Fig. 4-8

first part of sram1.rul file Fig. F-10

flow to interconnect parasitics 2-1

frozen database 3-10, 3-11, 6-8

frozen vs. unfrozen technology characteristics 4-1

fully automatic method 3-5

Fully Planar Process Fig. G-11

function of lateral spacing option 8-16

GGDS II stream F-2

General page

LPE Tools Interface Options window 8-5, 9-5, 10-5

Fig. 8-6LPE Tools Interface Options window Fig. 9-6,

10-6setting for SRAM example Fig. 8-20setting of LPE options for SRAM example Fig. F-8

generate graphics file option 11-7

Generate LPE File button 8-4, 9-4, 10-5

generating

capacitance tables 3-7excessive combinations, avoiding 4-9input file for RC3 F-15LPE file F-6LPE rule deck with capacitance models 2-2parasitics database F-6RC3 file option 11-8report 7-15rule decks with capacitance models F-7rule file 9-4, 10-5sample report 7-16

generic structure types 6-3

Generic Structurespanel 6-4properties 6-4

geometry and potential option 11-2

geometry only option 11-2

getting started

Field Solvers module 1-4Interconnect Library module 1-4Raphael 1-2Raphael Parasitics Database and LPE Tools

Interface module 1-3understanding Raphael main window 1-3

graphical results 7-6

Graphical User Interface see GUI

GRD files, invoking LPE Tools Interface 3-7

grdgenxo

metal fill effects G-6GUI conventions

keyboard 1-6menus 1-5mouse button 1-4window button 1-5

IICextract, Mentor Graphics LPE tool 10-1

include grounded Keyword option 9-16

information output during batch regression 7-9

insert base layer name 10-18

insights on lateral coupling capacitance modeling 8-10, 9-9, 10-10

insights on perimeter coefficient modeling 9-7

Interconnect Library module 1-4

ndex-4 RA 2006.03

Draft 2/6/06



Ind

ex

Fig. 12-3interconnect parasitics extraction, entire flow 2-1 to 2-3

Interconnect Technology Format (ITF) file G-1, H-1

cladding G-3conformal dielectrics G-3co-vertical conductors G-3dielectric air gaps G-4ITF process file G-1, H-2layer etch G-5

introduction 1-xiii to ??GUI conventions 1-4keyboard accelerators 1-6LPE Tools Interface 1-2typographical conventions 1-xiii

invoking LPE Tools Interface 3-7

ITF

file G-6ITF attributes not supported by Raphael G-20

ITF process file G-1, H-2

CONDUCTOR statement G-8DIELECTRIC statement G-7process cross-section G-2technology statement G-2VIA statement G-9

Kkeyboard accelerators 1-6

Llast part of sram.rul file Fig. F-13

lateral

capacitance G-6crowding G-6

lateral coupling capacitance 8-9

case 9-8layers 8-9modeling insights 8-10, 9-9, 10-10spacing 8-14

lateral coupling distance specification 8-9, 9-9

lateral coupling using the advanced equations Fig. 10-17

layer etch G-5

layout scaling factor 10-18

license F-1

limit value specification option 9-16

LPE files, generating F-6

LPE Layer Information panel 8-3, 9-3, 10-4

LPE options for SRAM example Fig. F-9

LPE rule decks 8-1, 9-1, 10-1

LPE Tools Interfacebutton 8-1, 9-1capacitance terminology 8-2, 9-2, 10-2changing layer information (optional) 8-3Diva and Vampire 9-1 to 9-21Dracula 8-1 to 8-22generating the rule file 8-4, 10-5ICextract 10-3introduction 1-2invoking 3-7option setting 8-5optional regression 6-12out-of-range values 8-4, 9-4overview 10-1selecting target LPE format 8-3, 10-3specifying the options (optional) 8-4xCalibre 10-3

LPE Tools Interface Options window 8-4, 9-4, 10-4

Diva & Vampire page 9-11Fig. 9-11

Dracula page 8-11Fig. 8-11

exporting and importing options 8-18General page 8-5, 9-5, 10-5

Fig. 8-6, 9-6, 10-6setting 9-5xCalibre & ICextract page 10-11

Fig. 10-12, 10-22LPE Tools Interface window 8-3, 9-1, 10-1, 10-4

Dracula 9-17, 10-19Fig. 8-2, 9-2, 10-2maximum distance 9-9, 10-10

Mmanual

copying and pasting 3-11database creation 3-7generation F-6

manually creating parasitics database 6-1 to ??actual structures 6-9menu bar 6-12overview 6-1performing manual simulation 6-8running simulation and regression analysis 6-10selecting actual structures 6-10

RA 2006.03 Index-5

Draft 2/6/06


I

selecting structures 6-2setting up the structures for simulation 6-1Tool Kit 6-12
manually regression analysis 7-3

mapping Dracula LPE layers to Raphael conductors F-6

mapping Raphael capacitance to LPE models D-1

marking a model 7-11

math functions 7-13

Mentor Graphics LPE tools

ICextract 8-1, 9-1, 10-1xCalibre 8-1, 9-1, 10-1

menu bar 4-17

menus 1-5, 3-9

Edit 3-9, 4-17, 6-12File 3-9, 4-17, 6-12File-Save Fig. 1-6Models 4-17Tools 11-10

MET1 above substrate structure 7-20

metal fill G-6

example G-19metal layers, overlap capacitance 8-9

models

array above ground plane D-1array between ground planes D-2array crossover above ground plane D-2array crossover between ground planes D-3coincident edge above ground plane D-4coincident edge between ground planes D-4different layers above ground plane D-5different layers between ground planes D-5oversize structure between ground planes D-5parallel arrays above ground plane D-4parallel arrays between ground planes D-4

Models menu 4-17

Models menu in Technology Characteristics window Fig. 4-18

modules

Field Solvers 1-4Interconnect Library 1-4Interconnect Library Fig. 12-3Parasitics Database and LPE Tools Interface

1-3mouse button 1-4

NNet Extraction System 1-4

New database name field 3-4

non-interacting metal layers 9-11

non-interacting metal modeling 8-11, 10-12

non-nearest layers 9-9

nonplanarized technology vs. planarized technology Fig. 4-11

Oone-array

equations 7-12model B-1models, mixing C-4

opening Raphael 1-2

option block E-8

options

append summary to output 11-3check input syntax only 11-1, 11-7constant value 8-14default 5-6function of lateral spacing 8-16, 9-14generate graphics file 11-7generating RC3 file 11-8geometry and potential 11-2geometry only 11-2include grounded Keyword 9-16independent preferences 8-4limit value specification 9-16send output to file 11-3, 11-9set matrix file name 11-8

Options menu for User Preferences notebook 3-12

Regression page 3-12Simulation page 3-12Structures page 3-12

output format 8-18

Output Terminal window 7-16, 8-4, 9-4

Diva & Vampire interface Fig. 9-5Dracula interface Fig. 8-5xCalibre & ICextract interface Fig. 10-5

output unit specification 8-11, 9-10, 10-11

overlap 8-2, 9-2, 10-2

overlap and lateral coupling capacitance components with associated structures Fig. 8-8, 9-8, 10-9

overlap capacitance case 9-8

overlap capacitance generation 8-9, 9-8, 10-9

overlap capacitance models 8-8, 9-11, 10-12

As a function of lateral spacing option Fig. 8-17

ndex-6 RA 2006.03

Draft 2/6/06



Ind

ex

As a function of lateral spacing option using extractParasitic command Fig. 8-17

based on 2D and 3D structures Fig. 8-7, 9-7based on 2D and 3D structures using

extractParasitic command Fig. 8-7

based on 2D and 3D structures using the xCalibre (and ICextract) syntax Fig. 10-8

Constant value option Fig. 8-15Constant value option using

extractParasitic command Fig. 8-15

Diva & Vampire syntax with as a function of lateral spacing option Fig. 9-15

Diva & Vampire syntax with split into sidewall up & down components option Fig. 9-14

Diva syntax with use simple syntax only option Fig. 9-16

Dracula 4.5 syntax with Split into sidewall up & down components option Fig. 8-16

extractParasitic command Fig. 8-14Fig. 8-13, 9-13

oversize structure between ground planes model D-5

PPage Tool window 7-21

pages

Diva & Vampire 9-11Fig. 9-11

Dracula 8-11Fig. 8-11

General 8-5, 9-5, 10-5Fig. 8-6, 9-6, 10-6

QuickCAP 11-4RC3 11-4Regression 3-12, 5-6, 5-7

Fig. 5-6Simulation 3-12, 5-4

Fig. 5-4Structures 3-12, 5-2

Fig. 5-3, 5-4xCalibre & ICextract 10-11

Fig. 10-22panels

Database Names 3-2Generic Structures 6-4LPE Layer Information 8-3, 9-3, 10-4

Parasitics Database & LPE Tools Interface F-3

Select a database 8-1, 9-1, 10-1Simulation and Regression 3-1Technology Characteristics 3-5Technology Parameters 4-3Width and Spacing Parameters 4-7, 7-20

parallel arrays

above ground plane model D-4between ground planes model D-4

parallel overlap 8-8, 9-7, 10-7

parameters

design E-1structure E-1

parametric library 12-2

parasitics database 7-15, 7-20, F-2

building 2-1creating F-3generating F-6setting user preferences F-6specifying technology characteristics F-3

Parasitics Database & LPE Tools Interfacebutton 10-1panel F-3

pathnames, defining in database directory 3-3

performing manual simulation 6-8

perimeter capacitance 8-2, 9-2, 10-2

perimeter coefficient modeling 8-5, 9-5

perimeter coefficient setting 8-14, 9-13

Planarized Technology button 4-10

Plot Inspector window 7-22

plots

capacitance to ground vs. space 7-21capacitance vs. spacing 7-20capacitance vs. width 7-20coupling capacitance vs. space 7-21regression analysis results Fig. 7-7total capacitance versus spacing Fig. 7-21total capacitance vs. space 7-21

pop-up window for Edit-Delete selected structures Fig. 6-13

preview structures for Automatically Create pop-up window Fig. 3-6

previewing structures 5-3

print regression information 10-18

process utilizing the layer etch adjustment Fig. G-5

process with conductor cladding Fig. G-15

process with conformal dielectric Fig. G-12

process with dielectric air gaps Fig. G-5, G-16

RA 2006.03 Index-7

Draft 2/6/06


I

process with gate poly Fig. G-13
process with layer etch Fig. G-17

process with local interconnect Fig. G-14

process with metal fill Fig. G-19

QQuickCAP page 11-4

RRA_PATH Raphael directory 1-1

RaphaelDracula interface redesigned 8-1flow to extract interconnect parasitics 2-1getting started 1-2parasitics database creation, example 1-1

Raphael Field Solvers History window 11-10

Raphael Field Solvers window 11-1

for RC2 Fig. 11-2RI3 Fig. 11-9

Raphael Interconnect Library (RIL) components and information flow Fig. 12-2

Raphael Interconnect Library see also RIL

Raphael main window 1-2, 8-1, 11-4

Raphael NES 8-20

Raphael Parasitics Database (RPD) module F-3

Raphael Parasitics Database and LPE Tools Interface module 1-3

Raphael Parasitics Database window 7-1

Automatically Create 3-5Automatically Create method Fig. 3-5defining pathnames 3-3defining technology characteristics 3-5Fig. 3-2, F-4Manually Create method Fig. 3-7Options menu for User Preferences notebook

3-12overview 3-1sample databases 3-2selecting new database name 3-4Simulation and Regression panel 3-1Technology Characteristics 3-5

Raphael/Dracula Interface example F-1

RC2 11-1

RC2-BEM 11-1

RC3

generating input file F-15

results, comparing F-15running field solver F-16

RC3 3D Interconnect Analyzer window 11-8

Fig. 11-5RC3 Field Solver window 11-4

RC3 Interconnect Analyzer 11-4

RC3 page 11-4

RC3-BEM 11-4

reflection boundary condition E-8

regression

batch vs. manual 7-2database creation 3-5default models (DRM) C-1

regression analysis 7-2 to 7-15

absolute error 10-18batch regression analysis 7-9field solver simulation 7-3graphical results 7-6key concepts 7-2limitations 7-13LPE tools 7-2manually 7-3menu bar 7-15model definitions B-1report 7-8results plot 7-6rule decks 7-2user-defined equations 7-11using Regression Analysis window 7-4

Regression Analysis Model Definitions B-1 to B-5

one array model B-1overview B-1two crossover array model B-2two parallel arrays model B-5user-defined equations B-1

Regression Analysis Results window 7-7

Fig. 7-8Regression Analysis window C-1

regression equations 10-15

Regression page 5-6, 5-7, C-1

location of default models 5-7location of user-defined equations 5-7User Preferences notebook for sram database

Fig. 5-6Regression tool 6-12

related publications

TCAD Products and Utilities Installation Manual 1-xiii

report for sram database, summarizing technology

ndex-8 RA 2006.03

Draft 2/6/06



Ind

ex

information Fig. 7-17

Report tool 6-12, 7-15

reports

generating 7-15sample report 7-16

restoring parameters or canceling 4-7

result of attempt to paste already-defined database pop-up window Fig. 3-10

RIL

overview 12-1parametric library of 30 structures 12-2starting 12-3

RIL... button 1-4

running

Dracula LPE F-14manual regression analysis 7-6RC3 field solver F-16simulation and regression analysis 6-10

running the xCalibre and ICextract LPE interface

generating the rule file 10-4specifying the options (optional) 10-4

Ssame-layer lateral coupling capacitance 8-2, 9-2, 10-2

sample databases 3-2

Save Report File window 7-15

Fig. 7-16Select a database panel 3-2, 8-1, 9-1, 10-1

select File-Save menu item Fig. 1-6

Select Structures window 4-2, 6-2

Select Structures window first two generic structures selected and exported, forming actual structures for sram database Fig. 6-3

Select tool 7-22

selected structure in the sram database Fig. 7-20

selecting

actual structures 6-10new database name 3-4target LPE format 9-3targets and models 7-5

selecting structures 6-2 to 6-8

exporting generic structures to create actual structures 6-7

generic structure types 6-3generic structures properties 6-4selecting actual structures and setting up for

simulation 6-8

send output to file option 11-3, 11-9

set matrix file name option 11-8

setting LPE interface options F-7

setting preferences 5-2

setting up the structures for simulation 6-1

setting user preferences F-6

Setup button 4-2, 6-8

sidewall down 8-2, 9-2, 10-2

sidewall up 8-2, 9-2, 10-2

sidewall up and down format 8-15

signal net G-6

simple syntax 9-16

simulation

and regression analysis, running 6-10, 6-11database creation 3-5input/output files 5-4, 5-5manual, performing 6-8status 6-11terminate 6-11

Simulation and Regression panel, Raphael Parasitics Database window 3-1

Simulation page 5-4

additional command line options 5-5simulation input/output files 5-4templates for generic structures 5-6User Preferences notebook for sram database

Fig. 5-4Simulation window E-8

specifying nonplanar technology characteristics 4-10

specifying options 9-4

specifying technology characteristics F-3

SPICE.DAT file Fig. F-15

SRAM

3D view of cell Fig. 8-19cell F-2, F-4cell layout Fig. 8-19, 9-18, 10-20, F-2cell viewed in Taurus Layout Fig. F-16example 8-19, 9-17, 10-20geometry of cell Fig. F-3Taurus Layout view of 2 x 2 array Fig. 8-22

sram database 7-16, 7-20

stack of dielectrics and conductors for SRAM example Fig. F-5

starting Raphael 1-2

status 6-11

status of the simulation 6-11

structure

actual 6-9

RA 2006.03 Index-9

Draft 2/6/06


I

MET1 above substrate 7-20parameters E-1parametric library 12-2selecting actual 6-10
Structures page 5-2, 5-3

2D selection 5-2applying preference settings 5-3crossover 5-2structures selection 5-2User Preferences notebook for sram database

Fig. 5-3, 5-4STUDIO Visualize window 7-21

Ttabular results 7-7

targets 7-10

Taurus Layout 1-4

Taurus Layout & Net Extraction System module button, Raphael main window 1-3

Taurus Layout main window F-16

Taurus Layout view of 2 x 2 SRAM array Fig. 8-22, 9-20, 10-23

TCAD Products and Utilities Installation Manual 1-xiii

technology characteristics 4-1 to 4-18

avoiding generating excessive combinations 4-9conductor values 4-3conductors positioning 4-6conformal dielectrics specification 4-7dielectric layers 4-3dielectric thickness 4-7frozen vs. unfrozen technology characteristics 4-1,

4-3manual copying and pasting 4-2menu bar 4-17overview 4-1specifying nonplanar technology characteristics 4-

10technology parameters 4-3width and spacing parameters 4-7, 4-8

Technology Characteristics window 4-1, 7-15, F-3

information for sram database Fig. 4-2SRAM Fig. F-5

technology characteristics, copying and pasting 3-10

Technology Characteristics, Raphael Parasitics Database window 3-5

technology parameters 4-3, E-1

Technology Parameters panel 4-3

templates

displaying field template 6-5field solvers E-1generic structures 5-6

Tool Kit 6-12

tools

Cap vs Space 6-12, 7-20Cap vs Width 6-12, 7-20overview 7-1Regression 6-12Report 6-12, 7-15Select 7-22utility, for manual database generation 7-1

Tools menu 11-10

total capacitance vs. space plot 7-21

trapezoid conductor traces with conformal dielectrics Fig. 4-7

two crossover array model B-2

two parallel arrays model B-5

two-array equations 7-12

typographical conventions 1-xiii

Uunderstanding Raphael main window 1-3

User Preferences notebook 5-1 to ??, F-6

choosing names 5-1overview 5-1Regression page 5-6, 5-7setting preferences 5-2Simulation page 5-4

Fig. 5-4Structures page 5-2

Fig. 5-3, 5-4user-defined equations

applying 7-11default files 5-7good fit B-1limitations 7-13math functions 7-13one-array 7-12overview 7-11parameters 7-14saving 7-13shared approach 7-14syntax 7-13two-array 7-12variables 7-13

using Dracula LPE Interface 8-3

using the Regression Analysis window 7-4

ndex-10 RA 2006.03

Draft 2/6/06



Ind

ex

Extract vs. Fix 7-5graphical results 7-6overview 7-5running a manual analysis 7-6selecting targets and models 7-5tabular results 7-7

utility tools for manual database generation 7-1

Vvariables, top array width and spacing 7-14

vertical overlap capacitance G-6

visualizing results 7-20

Wwidth and spacing parameters 4-7, 4-8

Width and Spacing Parameters panel 4-7, 7-20

width and spacing parameters, step size 4-9

window buttons 1-5

windows

Automatically Create pop-up Fig. 3-6Create/Inspect Parasitics Database 7-15, 7-

20Fig. 6-9

LPE Tools Interface 8-3, 9-1, 10-1, 10-4Fig. 8-2, 9-2, 10-2

LPE Tools Interface Options 8-4, 9-4, 10-4Diva & Vampire page 9-11Diva & Vampire page

Fig. 9-11Dracula page 8-11Dracula page

Fig. 8-11General page 8-5, 9-5General page

Fig. 8-6, 9-6, 10-6xCalibre & ICextract page Fig. 10-12

Output Terminal 7-16, 8-4, 9-4Page Tool 7-21Plot Inspector 7-22Raphael Field Solvers 11-1

for RC2 Fig. 11-2for RI3 Fig. 11-9

Raphael Field Solvers History 11-10Raphael main 1-3, 8-1, 11-4Raphael Parasitics Database 3-1, 7-1

Fig. 3-2, F-4

RC3 3D Interconnect Analyzer 11-8Fig. 11-5

RC3 Field Solver 11-4Regression Analysis C-1Regression Analysis Results 7-7

Fig. 7-8Save Report File 7-15

Fig. 7-16Select Structures 4-2

Fig. 6-3Simulation E-8STUDIO Visualize 7-21Taurus Layout F-16Technology Characteristics 4-1, 7-15, F-3

Fig. 4-2, 4-18SRAM example Fig. F-5

User Preferences notebook F-6Visualization 7-21

XxCalibre & ICextract page

LPE Tools Interface Options window 10-11LPE Tools Interface Options window Fig. 10-

12setting used for the SRAM example Fig. 10-22

xCalibre, Mentor Graphics LPE tool 10-1

RA 2006.03 Index-11

Draft 2/6/06


I


ndex-12 RA 2006.03

Draft 2/6/06

Date post:	18-Jun-2018
Category:	Documents
Upload:	phamnhan
View:	262 times
Download:	2 times

Interconnect Analysis Program Tutorialjmbussat/Physics290E/Fall-2006/... · Loading an Interconnect...

Documents