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EE143 Microfabrication Technology
Professor: Ali [email protected] Cory Hall(510) 643-7263
TAs:Zachary Jacobson (Head TA): [email protected] Lee: [email protected] Soltman: [email protected] Yeh: [email protected]
Web Page: http://www-inst.eecs.berkeley.edu/~ee143/
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Schedule• Lectures: Tue/Thu, 2:00pm-3:30pm• Labs (218 Cory) –
– Tu 10-1P – W 10-1P – W 2-5P – Th 9-12P– F 9-12P
LAB SECTIONS WILL BEGIN ON Sept. 2
• Office Hours:– Ali Javey (Cory Hall, 506)
Wednesdays, 10-11 am– TAs (TBD)
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Reading Material• Primary Text:
Introduction To Microelectronic FabricationR. C. JaegerPrentice Hall
• Reference Texts:Semiconductor Device FundamentalsR. F. PierretAddison Wesley
Device Electronics for Integrated CircuitsR. S. Muller and T. I. KaminsWiley
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Grading– Laboratory
• Includes quizzes, lab work, and reports
– Homeworks• 3-5 HW sets will be assigned throughout the semester
• You must work on your own– Tests (2)
• ~75 minutes each• given periodically per schedule• One sheet of notes allowed• No makeups
– Final Examination• Three sheets of notes allowed
30%
30%
35%
5%
We will follow the EECS grading guidelines for this class:
“A typical GPA for courses in the upper division is 2.9. (This GPA would result, for example, from 23% A's, 50% B's, 20% C's, 5% D's, and 2% F's.) A class whose GPA falls outside the range 2.7 - 3.1 should be considered atypical. A typical GPA for basic prerequisite upper division courses (EECS 104A, EECS 105, CS 150, CS 153) is 2.7 with GPA's outside the range 2.5 - 2.9 considered atypical.”
http://www.eecs.berkeley.edu/Policies/ugrad.grading.shtml
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Course Information
• Prerequisites:– EE40/E100 and Physics 7B or equivalent
• Course Description– EE143 teaches the fundamentals of integrated-circuit (IC) fabrication
and surface-micromachining technology, giving the student a basic understanding of IC and micromachining processes and the effect of processing choices on device performance. Students learn to use process simulation tools and also fabricate and characterize devices in the laboratory. This lecture part will cover the processing techniques and design methodologies of microfabrication. We will discuss the process modules: lithography, thermal oxidation, diffusion, ion implantation, etching, thin-film deposition, epitaxy, metallization. The second part of the course will cover process simulation, layout design rules, MOS, IC, and MEMS process integration. The laboratory part of the course will provide students opportunities to have hands-on experience to fabricate and characterize a NMOS chip with simple MEMS components.
Course Schedule
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Introduction to Materials and Processing (1-2 weeks)Photolithography (1 week)Etching (1 week)Oxidation (1 week)Deposition (1 week)Diffusion (1 week)Ion Implantation (1 week)Metallization/CMP (1 week)Simulation/Layout (1 week)Process Integration (1 week)Introduction to Devices (2 weeks)Nanolithography and Nanofabrication (1 week)
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Laboratory Information• We do our best to limit lab size to 12 people; as a result, your telebears
enrollment is not a guarantee of being assigned to a lab.
• You MUST send an email to Professor Javey ([email protected]) by Thursday 10pm including the following information:
– 1) Full Name– 2) Major– 3) Year (Jr., Sr., Grad student, etc.)
4) Rank list of preferred lab sections in descending order of preference (i.e., 1st
choice, 2nd choice…)– 5) List of any lab sections that you CANNOT attend
• Failure to send an email may result in you being dropped from the course, even if you are registered on telebears.
• Final lab assignment will be sent to you via email. PLEASE ENSURE THAT YOUR EMAIL ADDRESS ON TELEBEARS IS CORRECT, SINCE THIS WILL BE USED FOR OFFICIAL CORRESPONDENCE!!!
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Lab Safety
Week of 9/1• Mandatory Lab attendance required
• You will have a lab orientation session, and will have to pass a safety quiz before you are officially enrolled in this course.
• You MUST attend the lab session to which you are assigned.
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Course Structure – Lab and Lecture• You learn the theories in class; you practice them in
lab• You are going to make:
– resistors, diodes, MOS-cap– bipolar transistor, MOS-transistor, …– some MEMS structures, like bimorphs, …
• By the end of the semester, you should have learnt– basic lab techniques– how to operate some fabrication equipment– how to characterize the devices you made
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The EE143 Chip
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Lab Cleanliness• only enter the clean room fully gowned
– hair net + lab coat + glove + shoe net + safety goggles
• do NOT touch chemicals / equipment with bare hands
• always handle wafers with tweezers and trays (unless told otherwise)
• wash hands before and after entering the lab (why??)– before: so as not to contaminate wafers or
equipment– after: avoid chemicals being indigested
• 3rd week, GSIs will demonstrate how to clean masks
• 4th week, GSIs will demonstrate how to piranha- clean wafers
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Lab Safety• do NOT enter the lab when GSI aren’t present• know all the emergency exits (ask the GSIs to
show you)• know where to find the MSDS
– under the whiteboard in characterization room• know where to find the closet water sources,
shower, eye wash• ask whenever not clear• do NOT try things out without permission• NO eating, drinking, playing, etc. inside the lab• Things in the lab can be dangerous if not
carefully handled. Be sure to respect the chemicals.
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Chemical Handling• wear protective gear when handling corrosive chemicals
– face shield, chemical apron, chemical gloves, respirator if necessary
• check glove for holes• check pH of unknown spillage, label everything• corrosive chemicals: H2SO4, HF, aluminum etch, TMAH• wash and rinse the exposed body parts with water for >
15mins• add acids to water, not the other way around• handle wet chemicals only at sinks, acid on right, others on
left side
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Chemical Handling (cont’d)• HF:
– be very very careful– HF will penetrate your body and attack your skeletal
system; once you feel it, it is already eating your bones!!!– apply calcium gluconate if exposure is suspected– use only plastic beakers for HF (why??)
• H2SO4:– very painful, severely burns– add H2O2 to H2SO4 to prepare piranha– do not carry the beaker around after mixing (HOT!!)– use only glass beakers for piranha (why??)
• Chemicals used in the lab are often harmful. Don’t breathe and avoid exposure if possible.
• Use teflon-ware when handling wafers in acids. Be careful, those teflon tweezers do not hold the wafers very well!!
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Chemical Disposal• organic chemicals are discarded in designated
containers• NOTE: in this lab, photoresist (PR) is also
dumped down the drain.• do NOT mix organic wastes with acids (why??)
– can cause fire or even explosion• do NOT mix acids and bases•
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Note: Not drawn to scale
Lab Floor Plan
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• Microfabrication Principles for IC and MEMS• Hands-on Fabrication and Testing of IC and MEMS Devices
EE143 Overview
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Fabricated Structures• Using a series of planar processing steps, it is possible to
create sophisticated 3D electrical and mechanical structures.
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17-stage Ring Oscillator
Electrical Functionality / Characterization• The resulting structures may be characterization
electrically or mechanically
EE143 – Ali Javey Slide 0-20Responsive Drug Delivery Valve
Gear Speed Reduction Unit Movable Mirror
Turbine engine
MEMS ActuatorsMEMS Actuators
Introduction to Si Processing EE143 in one day
Silicon Device Fabrication Technology
Over 1019 transistors (or 1,000,000,000 for every person in the world) are manufactured every year.
Variations of this versatile technology are used for flat-panel displays, micro-electro-mechanical systems (MEMS), and even DNA chips for DNA screening...
Terminology
SSI (Small Scale Integration) – few transistorsMSI (Medium Scale Integration) – hundreds
LSI (Large Scale Integration) - thousandsVLSI (Very Large Scale Integration) - millions
ULSI (Ultra Large Scale Integration)
Foundry (Fab)• Foundry (also called a fab for fabrication
plant) is used to refer to a factory where devices like integrated circuits are manufactured. The central part of a fab is a cleanroom.
• Note the difference between a fab and a lab.
Cleanroom Standards
Federal Standard Class Limits
CLASSMEASURED PARTICLE SIZE (MICROMETERS)
0.1 0.2 0.3 0.5 5.0
1 35 7.5 3 1 NA
10 350 75 30 10 NA
100 NA 750 300 100 NA
1,000 NA NA NA 1,000 7
10,000 NA NA NA 10,000 70
100,000 NA NA NA 100,000 700
Why do we need cleanrooms?
Introduction to Device Fabrication
Oxidation
Lithography &Etching
Ion Implantation
Annealing & Diffusion
Deposition
Oxidation of SiliconSi + O2 →
SiO2
Si +2H2 O → SiO2 + 2H2
Dry Oxidation :
Wet Oxidation :
Thin oxide
Thick oxide
Si Wafers
O2 N2
H2O or TCE(trichloroethylene)
Quartz tube
Resistance-heated furnace
Flowcontroller
Oxidation of Silicon
Lithography
Resist Coating
Exposure
Development
Etching and Resist Strip
Photoresist
OxideSi(a)
OpticalLens system
Deep Ultraviolet Light
Photomask withopaque and
clear patterns
Si Si
SiSi
Positive resist Negative resist
(c)
(d)(b)
Pattern Transfer–EtchingIsotropic etching Anisotropic etching
SiO2
SiO2
SiO2
(1)
(2)
(3)
photoresist
photoresist
SiO2
(1)
(2)
photoresist
photoresist
SiO2
SiO2
(3)
wet etch dry etch
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Ion Energy~1 keV to200 keV
Module: Ion Implantation
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ProcessingSteps
Si wafer
What is process integration?• Sequential use of a series of simple process steps or
“modules” to create complex structures
Slide 0-32
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The EE143 Lab Process (part I)
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The EE143 Lab Process (Part II)