ITRS Spring Conference 2009 Brussels, Belgium 1 Work in Progress: Not for Distribution 2009 ITRS...

ITRS Spring Conference 2009 Brussels, Belgium 1

Work in Progress: Not for Distribution

2009 ITRS

Emerging Research Materials

[ERM] REVISED 3/20

March 18-20, 2009

Michael Garner – IntelDaniel Herr – SRC



Emerging Research Materials 2009 Scope

• Emerging Device Materials– Logic CMOS Extension( III-V, Ge, Graphene, CNT, NW)– Beyond CMOS Logic (Spin, Molecular, Metal-Insulator Transition)– Memory

• Molecular• Oxide (FE & Resistance Change)

• Lithography – Dual Exposure Resist, Non CAR, Pixillated resist, Novel Mechanisms– Directed Self Assembly: Chemical Pattern & Physical Patterning

• FEP (Deterministic Doping)• Interconnects (CNT Vias & Interconnects, Cu NW, Ultrathin Cu Barriers,

Low K ILD Needs)• Assembly & Package

– Chip attach: CNTs, Nanosolders, and Conductive Adhesives– Package Polymers (Nanocomposites & Novel Macromolecules)– Thermal Interface Materials (CNT, others)

• ESH (Earliest insertion opportunity & Prioritized)• Metrology (New needs: Domain & domain wall characterization, Soft

material characterization & DSA defect recognition)• Modeling (Structure property correlations)



7:30 Gathering time 8:00 Introductions 8:10 Review meeting objectives and agenda Hutchby 8:20 Review of Administrative Aspects Hutchby

Deliverables, Timeline, Events, & Next Steps Chapter Outline, Page Count & Allocation Cross TWG Linkages & Meetings

8:30 Review/Discuss Status of Major Tech Sections Section outline Table structure (Row headers, etc.) Table Content (Current & projected tables) Key materials issues

8:30 Memory Devices Zhirnov10:00 Break

ITRS ERD WG Meeting – March 18, 2009Agenda



10:15 Logic Devices Bourianoff11:45 MASTAR Readiness for III-V & Ge MOSFETs Ng12:00 Lunch12:30 Emerging Research Materials Garner 1:30 Architectures Cavin 2:30 Discuss/Decide Difficult Challenges Hutchby 3:15 Discuss Evaluation & Guidance Sections

3:15 Critical Assessment Hutchby 3:45 Guiding Principles Hutchby

4:00 Discuss Proposal for Highlighting Promising HutchbyOptions for Emerging Memory Technologies

4:45 Review ERD/ERM Beyond CMOS IRC Pres. All 5:25 Wrap up and Review Actions Required All 5:30 Adjourn

ITRS ERD WG Meeting – March 18, 2009Agenda



ERM Agenda March 19, 2009

Time Subject Location

9:00 -10:00 Plenary Plenary RM

10:00-11:00 Europe Nanotube Update ERM Area

11:00-11:30 Assembly & Package & Litho Messages

ERM Area

11:30-12:30 Assembly & Packaging TWG -ERM

A&P Area

12:30-13:30 Lunch

13:30-14:00 Litho TWG Meeting Litho Area

14:00-14:45 ESH Table, Modeling Needs ERM Area

14:45-15:30 ESH TWG-ERM ESH Area





15:30-16:30 Modeling TWG-ERM Modeling Area

16:30-17:00 Interconnect Needs & Assessment

ERM Area

17:00-17:45 Nanotube Discussion ERM Area

17:45 Adjourn

18:00 ITRS Dinner





9:00-10:00 Beyond CMOS Plenary RM

10:00-11:00 Interconnect TWG-ERM Interconnect Area

11:00-11:45 FEP TWG - ERM FEP Area

11:45-12:30 PIDS TWG -ERM PIDS Area

12:30-14:00 Lunch (Plenary Presentations Due)

14:00-14:45 ERD/ERM ERM Room

14:45-15:30 ERM Preparation Litho Area





15:30-16:00 ERM, ERD, FEP, PIDS Alignment

TBD

16:00-16:30 Metrology TWG-ERM Metrology Area

16:30-18:15 Plenary Plenary RM

18:15 Adjourn



2009 ERM Workshops• F-t-F: Novel Macromolecules: ~February 28,

2009, SF Bay Area: Aligned with SPIE Microlithography Symposium.

• F-t-F: ERM Complex & Strongly Correlated Electron Materials, Early March ‘09, Japan

• E-WS: Complex Metal Oxides January ~18, 2009

• Modeling WS SF MRS• Metrology WS Albany, May 2009



Emerging Research Materials 2009

• Establish ERM Outline and Writing Assignments • Refine Critical Assessment Process

– CMOS Extension: Detailed Critical Assessment– Beyond CMOS: Trends on critical materials & properties– Update Key Challenges Tables

• Plan Workshops on ERM– All workshops should identify Metrology, Modeling and ESH

support as appropriate

• Finalize new materials needs based on ITWG inputs– ERD, Lithography, FEP, Interconnects, Assembly &

Packaging, PIDS– Establish Concrete targets– Functional Diversification



ERM Outline• Scope• Introduction• Difficult Challenges• Challenges for Multi-application ERM (Back-up?)• Materials for Alternate Channel CMOS (PIDS & ERD)

– Critical Assessment• ERM for Beyond CMOS Logic (ERD)• Materials for Memory Devices

– Critical Assessment• ERM for Lithography

– Resist (pixilated, multi exposure resist, Mon CAR, novel)– Self Assembled Materials– Transition Table (Molecular glasses, evolutionary resist macromolecular design, etc.)

• ERM for FEP & PIDS– Deterministic Doping– Self Assembly for Selective Deposition & Etch

• ERM for Interconnects• ERM for Assembly & Package• ERM ESH Research Needs• ERM Metrology Needs• ERM Modeling Needs



X-cutting Challenges

• LDM– Control of placement & direction– Control of nanostructure, properties & macro properties

• Contact & Interface issues• Self Assembled Materials

– Control of placement, defects, and registration

• Complex metal oxides– Control of properties, interfaces, defects, and moisture

degradation



Materials for Alternate Channel CMOS

• III-V & Ge (John Carruthers)• Semiconductor Nanowires (Ted Kamins)• Graphene (Daniel Bensahel)• Carbon Nanotubes (Jean Dijon)

Alternate Channel Materials Evaluation

Capability

Demonstrated High Mobility in n-

channel

Demonstrated High Mobility in p-

channelProperty Control

(Eg, etc.)

Gate Dielectric Compatibility &

Control

Low Contact Resistance & Variability

CMOS Compatibility

Control of Location & Direction

Surface Passivation

Research Target >5000cm2/ V-sec. >5000cm2/ V-sec. 10% (1σ)

Unpinned Fermi Level, 10% thickness (1σ)

Comparable to CMOS

Depends on Device Structure, Process

Architecture & Integration 10% of Half Pitch < 1e11cm-3

III-V Ge

Graphene Bi-Graphene

SW CNT

Nanowires

Average #REF! #REF! #REF! #REF! #REF! #REF! #REF! #REF! #REF! #REF!StdDev #REF! #REF! #REF! #REF! #REF! #REF! #REF! #REF! #REF! #REF!

Logic Device Materials



III-V Ge Alternate Channel Partition Proposal

ERM

Materials, Interfaces & Process Issues & Challenges

Critical Assessment of Materials & Integration Capabilities

ERD

Integrated Device Performance Assessment & Challenges

(For different structures surface, buried channel, etc.)

Critical Assessment of Device Performance

PIDS

III-V & Ge Potential Solution

SiGe P-FET with Si N-FET

Collaborate with ERD on device Readiness

FEP

Potential Solution: SiGe P-FET with Si N-FET

III-V & Ge Potential Solution

Track III-V & Ge Issues


Work in Progress: Not for Distribution15

Production Ramp-up Model and Technology Cycle Timing

Volu

me

(Par

ts/M

onth

)

1K

10K

100K

Months0-24

1M

10M

100M

AlphaTool

12 24-12

Development Production

BetaTool

ProductionTool

First Conf.

Papers

First Two CompaniesReaching

Production

Volu

me

(Waf

ers/

Mon

th)

2

20

200

2K

20K

200K

Source: 2005 ITRS - Exec. Summary Fig 3

Fig 3 2008 - Unchanged



Next Steps

• Key Items to Resolve before March ITRS– ERM Assessment Criteria

• Establish Research Targets

– Review ERD Criteria– PIDS Draft Potential Solution Statement– FEP Draft HVM Capability Requirements



ERM Device Materials Outline

Emerging Logic Materials • Alternate Channel Materials for Equivalent Scaling• III-V Epi Materials• Ge Epi Materials• Graphite and Graphitic Materials• Nanowires• Carbon Nanotubes• Critical Assessment• Contact Materials (?)• Beyond CMOS Logic Materials• Spin Materials• Ferromagnetic Semiconductors (III-V & Oxides)• Magnetoelectric Materials (Alloys, Heterostructures, superlattices)• Spin Injection Materials (Low barrier ferromagnetic metals, half metals, etc)• Spin Tunnel Barriers (MgO, etc)• Semiconductor & nanostructure Spin Transport properties (Si, Ge, Graphene, CNT, etc), • Strongly Correlated Electron State Materials (Metal-Insulator)• Molecular Devices (?)• Emerging Memory Materials• Molecular Devices (?)• Complex Metal Oxides• Critical Assessment (?)



Materials for Alternate Channel Logic

• Alternate Channel Materials for Equivalent Scaling

• III-V Epi Materials (John Carruthers)• Ge Epi Materials (John Carruthers)• Graphite and Graphitic Materials (Jeff Peterson &

Daniel Bensahel)• Nanowires (Ted Kamins)• Carbon Nanotubes (Jean Dijon)• Critical Assessment• Novel S/D Contact Materials (?)



III-V & Ge Key Messages

• Gate Dielectric Growth techniques are being developed – Current Approaches (III-V):

• MBE Growth of III-V/Ga2O3/GdGaO Stack (Freescale)• As Cap/ In situ As decap +ALD HfO2 (Stanford)• NH4OH-ALD Al2O3 or HfO2 on III-V (Purdue)• InAlAs Barrier (MIT)

– Current Approaches (Ge):• GeOxNy Nitridation (Stanford)• Ozone Oxidized Ge + ALD High κ dielectric HfO2 (Stanford) • LaGeOx-ZrO2(Ge) High K (Dual Logic)

• Controlling surface oxide formation is critical for control of interface states– Control of interface stochiometry, structure and defects is critical– GeOx stochiometry control affected by growth temperature



III-V & Ge Key Messages

• Ge dopant activation requires high temperature – Incompatible with III-V process temperatures

• S/D Contact Formation Current Approaches:– Ge

• P-MOS: Boron with many ohmic metal contact options

• N-MOS: Dopants have high diffusivity & metals schottky barriers

– III-V• W contact/InGaAs cap/InAlAs (MIT)

• Are barriers needed to keep dislocations out of the channel?



III-V Ge Heteroepitaxy Challenges

• Reduction of dislocation densities• Control of stress in III-V & Ge integrated on Si

– Ultrathin films– Heterostructures to reduce defects

• Effect of antiphase domains on carrier transport

• Identify a crystal orientation that favors epitaxy and interface states.



Graphene Challenges & Status

• Ability to deposit graphene on appropriate substrates

• Producing a bandgap– Fabricating Narrow Graphene Lines– Applying a high electric field to bi-graphene

• Achieving high mobility in an integrated structure

• Achieving a high on-off conduction ratio



Graphene Deposition

• CVD of Graphene on Ni, Pt, and Ir– Graphene is strongly bonded to Ni, but has a lattice match– Graphene deposited on Pt is not distorted, is not lattice matched,

but is weakly bonded• SiC decomposition

– Issue: High process temperature (>1100C)• Exfoliation Techniques

– Graphene Oxide Decomposition (Mobility <1000cm2/V-sec)• Oxidation process produced islands of graphene surrounded by

disordered material (hoping conduction)– Try less aggressive oxidation process

– Solvent exfoliation• Solvents capable of separating graphene sheets are difficult to

evaporate (high boiling point)– Tape exfoliation



Producing a Graphene Bandgap

• Fabricating Narrow Graphene Lines– Requires patterning sub

20nm lines– Edge defect control is

challenging (Eg & Mobility)

• Applying a high electric field to bi-graphene– Field ~1E7 V/cm



Graphene Mobility

• Mobility on substrates is reduced

• Graphene Oxide Mobility – Degraded by disordered

regions



Nanowire Challenges

Based on 2007 ERM the key challenges were:• Position the nanowires during growth or reposition

them after growth at the desired location and with the desired direction

• Provide performance exceeding patterned materials• CMOS compatible catalysts.• Additional

– Integration of dopants– Gate Dielectric interface passivation



Nanotube Challenges

• Control of:– Location– Direction– Bandgap (Chirality & Diameter)– Carrier type & concentration

• Gate Dielectric Deposition• Contact Resistance



Nanowire 2009 Potential Technology Advantages• Status of demonstrationKey Challenges & Status• Position the nanowires during growth or reposition

them after growth at the desired location and with the desired direction

• Provide performance exceeding patterned materials• CMOS compatible catalysts.• Additional

– Integration of dopants– Gate Dielectric interface passivation



Critical Assessment

Alternate Channel Materials Evaluation

Capability

Demonstrated High Mobility in n-

channel

Demonstrated High Mobility in p-

channelProperty Control

(Eg, etc.)

Density of States (In the Inversion Channel Band)

Gate Dielectric Compatibility &

Control

Low Contact Resistance & Variability

CMOS Compatibility

Control of Location & Direction

Surface Passivation

Research Target >5000cm2/ V-sec. >5000cm2/ V-sec. 10% (1σ) TBD

Unpinned Fermi Level, 10% thickness (1σ)

Comparable to CMOS

Depends on Device Structure, Process

Architecture & Integration 10% of Half Pitch < 1e11cm-3

Development Target

III-V Ge

Graphene SW CNT

Nanowires

Add a category: Potential Extendability to Beyond CMOS

Saturation Velocity



Beyond CMOSM. Garner

• Molecular State (Alex Bratkovski & Curt Richter)• Spin Materials (U-In / Kang Wang)

– Ferromagnetic Semiconductors (III-V & Oxides)– Magnetoelectric Materials (Alloys, Heterostructures,

superlattices)– Spin Injection Materials (Low barrier ferromagnetic metals,

half metals, etc)– Spin Tunnel Barriers (MgO, etc)– Semiconductor & nanostructure Spin Transport properties

(Si, Ge, Graphene, CNT, etc),



ERM Beyond CMOS Scope: 2009 2007 Transition In Transition Out 2009

Molecules & Interfaces

Transition out? Inadequate progress

Status

FM Semiconductors

Curie Temp Table

Tc Graph

FM Oxide Semiconductors

Status, Table or Graph

Spin Semiconductor

Status

Spin Tunnel Materials

Status

Magnetoelectric materials & structures

Status

Low barrier spin injection materials

Status



Spin Materials

• Ferromagnetic III-V (Mn) semiconductors have verified Curie temperatures 100-200K– Carrier mediated exchange

• Nanowires of GeMn have reported ferromagnetic properties at 300K+, but carrier mediated exchange with gated structure is difficult to verify

• Oxides doped with transition metals have ferromagnetic properties– Ferromagnetism can be controlled with carrier doping, but it

isn’t clear whether this can be modulated with electric fields– Ferromagnetism is proposed to be in an impurity band vs.

the oxide bands.– It is not clear whether this is useful for device applications



Spin Materials (Cont.)• Spin Tunnel Barrier Materials

– MgO crystalline material is the best spin selective tunnel barrier to date

• May work with a limited number of materials due to lattice match requirement

– Films must be ~9A thick– Al2O3 films work, but with much lower selectivity

• Multiferroics– Need higher coupling coefficient (Electrical to Magnetic)

• Nanostructures• Heterostructures

– BaFeO3 has ferroelectric & antiferromagnetic properties coupled

• Limited degrees of freedom & low coupling



Strongly Correlated Electron State Materials (For Spin Logic)

• Potential Physics of Interest– Competing Non-Ferromagnetic/ Ferromagnetic Phase

Transitions• Nanoscale phase segregation near phase transition

compositions• Magnetic fields can convert the phases (multi Tesla)

– Insulator to Ferromagnetic Metallic state• Carrier doping may be able to cause the transitions

– Electric Field

– Issues: • Most phase transitions occur below room temperature• Phase transitions may be first order• “Pure” phases may not exist (Nanoscale phase segregation)



Strongly Correlated Electron State Heterointerfaces (For Spin Logic)

• Oxide heterointerfaces don’t appear to have interface pinning

• Interfacial reconstruction at charged interfaces– Charged interfaces result in interface

reconstruction– Hole doped interfaces are “metallic”



Phase Competition



Nanoscale Phase Segregation



1st Order Phase Transitions

• Coexistence of competing phases



Heterostructures



Heterostructures

• Surface reconstruction hole generation• No polar discontinuity except at STO/LaAlO3

interface



ERM Beyond MOS Memory: 2009 2007 Transition In Transition Out 2009

Complex Metal Oxide Resistance Change

Status

Oxides & Interfaces FE Memory

Status

Nanotube for Nanomechanical memory

Status

Molecules & interfaces for Molecular Memory

Transition out? Status

MRAM Materials Status

Ionic Transport Materials



Oxide Memory Materials• Multiple mechanisms proposed

– Phase transformation– Change of polarization alignment (E or H)– Nanofilament formation– Cation migration

• Role of vacancy concentration on cation migration?

– Anion Migration• Role of vacancy concentration on anion migration?

• Should we assess the consequences of the different mechanisms? (Scaling & Reliability)– Resistance Change – Ferroelectric FET & Barrier– Mott FET



Mechanism Assessment• Cation migration (Ag, Cu) Filament formation

– Vacancy concentration dependence

• Anion migration– Vacancy concentration dependence

• Charge Trapping sites and effects• Electronic Phase Transition

– Mott FET



C. Dubourdieu - LMGP-CNRS & D. Bensahel - STMicroelectronics - France 44

In December 2007, the journal Science considered the recent discoveries emerging from oxide interfaces as one of the 10 breakthrough of the year 2007

Oxides interfaces

-New properties arise from surface, electronic or orbital reconstructions. (Stacking for example two insulating compounds such as LaAlO3 and SrTiO3 can lead to a metallic or superconducting LaAlO3/SrTiO3 interface)

-Interfaces in superlattices can change the nature of the coupling between competing instabilities and produce new properties.(superlattices combining the proper ferroelectric PbTiO3 and the paraelectric SrTiO3 compounds behave like a prototypical improper ferroelectric due to interface coupling based on rotational distortions).



Memory & Oxides

Device Materials Material Mechanisms

Interface Mechanisms

Thermal Resistance Change

NW Chalcogenides

Thermal Amorphous Chrystal Phase Change

Electrochemical Resistance Change

Cu & Ag with Oxides or sulfides

TiO2, CuO

Cation or Anion Migration

Electrochemical

Charge Trapping



Memory & PerovskitesDevice Materials Material

MechanismsInterface Mechanisms

FE FET PZT, BFO Ferroelectric Polarization

Electrodes can degrade reliability

Pt: Hydrogen: SRO preferred

FE Barrier (DROP) Check with Victor

PZT, BFO, etc.

Ferroelectric Polarization changes Schottky Barrier height or charge

TBD

Mott FET PCMO, LCMO, STO

Carrier injection drives a metal insulator transition

TBD



Perovskite Challenges• Ferroelectrics: Electrode Interactions

– Pt: Hydrogen ion generation degrades polarization– SRO: Increases resistance

• Strongly Correlated Electron Material Challenges (Mott M-I Transition)– Nanoscale phase segregation may suppress sharp transition– Materials are very sensitive to stress (Piezo effects)

• Selection of substrate & interface layers

– “Disorder” can dramatically reduce critical temperatures



Molecular Devices

• Top contact formation is still a significant issue

• Determining that switching is due to the molecular energy levels is difficult



ERM for Lithography(Dan Herr, Bill Hinsberg, & Atsushi Shiota)

• ERM for Patterning – Novel Macromolecules for Resist

• Multi wavelength resist (Dual exposure)• Pixellated resist

– Novel Macromolecules for Contrast Enhancement Layer• Multi wavelength CEL (Dual Exposure) (Drop?)

– Novel molecules for Non CAR (TBD at Workshop)– DSA Materials– Imprint molecules (Transition? )

• Functional materials

• ERM for Immersion Fluids – Nanoparticles for immersion fluids (Transition Table?)



Litho 2008– General:

• ERM requested confirmation of timing, metric families, and quantitative metrics

– 3rd generation immersion lithography technology:• There was considerable discussion on this topic;• Concern was expressed that this technology may be pushed out too far

to meet required insertion windows;• 2012 insertion appears unlikely • It was agreed that the ERM WG would wait for the Litho TWG to

address this issue and make a recommendation; – Novel macromolecules for resist applications:

• Use the same criteria as is used for resist. – Increased interest in intermediate state photochemistry, chemical

image enhancement, two photon patterning, imprint, optical threshold layers, and non-CAR systems

– Nanoparticles:• Drop the optics abrasion requirement, since this would be a difficult

property for the university research community to characterize; – Directed self assembly for patterning applications:

• The Lithography ITWG reviewed the DSA research requirements and agreed to provide feedback at a later date.



ERM Litho Scope: 2009 2007 Transition In Transition Out 2009

Resist Molecular Design

To Litho TWG

Molecular Glasses To Litho TWG

Pixillated Resist Assess

Directed Self Assembly

Assess

Dual Exposure Resist Molecules

Into ERM Does it have a window of opportunity?

Assess at WS

Dual Wavelength CEL Layer Molecules

Into ERM Assess at WS (Drop?)

Non-CAR Molecules

Into ERM Access at WS

High index Immersion Fluids

Transition out? TBD

Imprint Molecules

Imprint Resist?

Evolutionary, Remove?

TBD



Macromolecules for Resist

• Approaches focus on decreasing feature size and LER– Molecular Glasses: Increase homogeneity– Non CAR: Photoactive polymer scission– Pixillated resist– Double Exposure Materials

• 2 Stage rCEL (Not Viable)• 2 stage PAG molecules

– Requirements (stage 1 reversable)– Tethered Anthracene Family– Photoinduced phase change to modulate acid diffusion

– Pattern collapse is a serious challenge for all resist– Metrology Needs LER



Molecular Glasses



Non CAR Resist

• Require higher intensity exposure• Improved source intensity and lens life at higher intensity



Pixillated Resist





Double Exposure Resist







Summary from WorkshopNovel chemical system for advanced lithography

Objective of the workshopDiscuss alternative approaches to self assembly and conventional CAR for EUVL. Materials contributions to the future lithography are how to increase resolution and how to decrease LWR.

Technology discussed1. Non chemical amplified resist (non-CAR)2. Negative tone photoresist3. Intermediate State Two-Photon Material (ISTP)4. Optical Threshold Layer (OTL)

Outcomes• New un-zipping mechanisms were proposed and demonstrated reduction of LWR.• Negative tone cross-linking may eliminate acid diffusions but cross linking or polymer propagation

competing to diffusion controlled also should be minimised.• Molecular glass itself cannot solve the LWR issues, homogeneity would be a key.• ISTP mechanism were demonstrated in 254nm. ISTP generates “acid” in dual wavelengths and

PAGs and sensitizers not undergoing both exposures must revert to an original state• Photo/Thermal initiated phase changes can be utilised a chemical mask to control diffusions. The

concept was proven.



61Contribution of Uniformity in Molecular Glass Architectures

Presentation from Prof. Henderson @ GT• Some have shown dramatically better LER at high speeds as compared to

conventional CARs• Good resolution can be achieved by reduction in acid diffusion• Sensitivity is lower than expected, but can be improved based on studies of non-

ionic PAG behavior under high energy.• Binding sulfonic acid and PAG to molecular glass cores provides potential path

forward in resist design required for high resolution and low LER.

O

O

OCH3

S O

O

O

N

O

O

O

O

S+

O

O

O O

O

O

O

O

O

SbF6

S

O

O

O

S

O

O

-OO

I+

O

O

S

O

O

OO

N

O

OCN



Self-Developing ResistsPresentation from Prof. Whittaker @ UQ

• Synthesis– Alternating copolymer of

sulfur dioxide and an alkene

O

S

O

R+

I

+

SS

S

O

O

R

O

O

RRO

O hv

I SS

S

O

O

R

O

O

RRO

O

I

hv

PEB

S

O

OR

+

PEB

S

RO

O

IR

• Exposure– Sulfur dioxide is an excellent leaving group

and absorption of a photon can result in chain scission

• Post Exposure Bake– Radicals generated as a result of chain

scission will initiate depolymerisation when film is baked above Tc



PAGSensitizerLatent

h

H+

PAG

Step 1

1

1

PAG

Step 2

2

PAGSensitizer Sensitizer

e-

Step 3

h

H+

ISTP Proof-of-Principle Acid Generation SystemPresentation from Prof. Wilson @ UT

O

O

OMe*

OMe

O

N

O

O

OTf

N. O’Connor et al. Chem Mat. 2008 (accepted)

254 nm 254 nm

Successful demonstration of proof-of-principle system



Wafer

First ExposurePhase changeDiffusion and reaction occursFlood ExposureSecond ExposureStrip the top two layersEtch

Putting It Together: Possible Patterning with OTLPresentation from Prof. Wilson @ UT

Feeder LayerOptical Threshold LayerAcceptor Layer

Feeder Acceptor Product with High Etch Resistance

Photo-induced phase/permeability change

Below threshold exposure dose

Low permeability for feeder layer

High permeability for feeder layer

Above threshold exposure dose

Use phase/permeability change to change etch resistance



Leading two-stage approach:Presentation from Dr. Bristol @ Intel

X

X

X

2193nm

350-365nm

193nm

350-365nm

untethered cycloadduct

tethered cycloadduct

193nm

X

X

X

X

H-X

193nmH-X

Photochromic Switches Based on 4π + 4π cycloaddition

Naphthalene-based: Naphtali A. O’Connor, Adam J. Berro, Jeffrey R. Lancaster, Xinyu Gu, Steffen Jockusch, Tomoki Nagai, Toshiyuki Ogata, Saul Lee, Paul Zimmerman, C. Grant Willson and Nicholas J. Turro, Chem. Matr., 20 pp7365-7524, (2008).



Progress in Directed Self Assembly

• Use of Alignment “fiducial” structures to force long range order (Cylindrical structures)

• Use surface energy to force dense self assembly to sparse patterns

• Scalability: Features demonstrated to 7nm• Patterns: Square “Cylindrical Arrays”

Demonstrated



Fiducials to Force Long Range Order



Sparse Pattern Assembly

• Pinning feature needs to match self assembly feature size• DSA can “heal” defects in the pinning layer• Defect levels need to be determined



Square “Contact” Arrays

• Modular tunable Supramolecular Tri-block approach may enable new structures



Critical Assessment

Demonstrated resolution

Defect Density Speed LER

Ability to Simultaneously

Achieve Resolution,

Sensitivity, and Line Edge Roughness

Etch Compatibility (hard mask compatible)

Outgassing (EUV) Stripablity

Research Target

Novel Molecules for Dual Exposure Resist

Novel Molecules for Dual Exposure CEL

Non CAR Resist

Self Assembly (graphepitaxy)

Photopatternable self assemblySurface Patterned Self Assembly

Rating Person

Lithography Materials Evaluation Table: Novel Macromolecules

Average Potential

Sum Potential



ERM for FEPDan Herr

• Deterministic Doping– Research Equipment Options– Self Assembly Driven

• Selective Etches & Cleans– Research or Engineering?

• Selective Deposition



FEP 2008– General:– FEP will provide feedback on specific material assessment criterion

• For selective deposition processes:– Focus on techniques to deposit graphene on silicon and processes for

selective deposition of III-V compounds – Graphene:

• Assess cleaning chemistries, processing, and edge passivation – III-V Alternate channel materials:

• Assess cleaning chemistries, processing, and edge passivation – Directed self assembly:

• Establish deterministic doping targets and requirements– Dielectric materials:

• Establish and assess projected high- research requirements for the DRAM capacitor, especially at projected film thicknesses

• The current FEP requirements table shows that the dielectric constant is projected to reach 120, and then decrease to ~90, which appears to be unrealistic. FEP will resolve this apparent inconsistency.

– Spin materials:• Add to FEP’s ERM assessment tables



ERM FEP/PIDS 2009 Scope2007 Transition In Transition Out 2009

Directed Self Assembly (DSA) for Deterministic Doping

Status

Shuttered Implant for Deterministic Doping

Into ERM Status & Challenges

DSA Selective Deposition

Status & Challenges

DSA Selective Etch Research or Engineering?

Status & Challenges

DSA Selective Cleans

Engineering Stats & Challenges



Deterministic Doping Potential Options Considered

Ion Implantation

Shallow doping via SAMs

STM positioning

Other potential options cited: Directed Self-Assembly



Ultra Shallow Chemical Doping

75

Strategy:1. Boron monolayer formation on

Si2. Capping with SiO2 cap

3. RTA to diffuse the B atoms

Johnny Ho, et al, Nature Materials, 2008.

UC-Berkeley

Objectives: Ultra-shallow junction formation Precise control over the dose at

nanoscale MS junctions with heavily doped

“self-aligned” semiconductor for NW and planar device geometries

Chemistry is important for nano devices!



STM-Device Patterning: Summary

76UNSW



• High placement accuracy methods, <1 nm, i.e. STM– Not likely to become manufacturable

• Massively parallel approaches face significant data management challenges.

– Potentially useful for understanding device limits and new functionality, such as symmetry and quantum effects

• Medium placement accuracy methods, ~10 nm, i.e. Single Ion Implantation– Exhibit potential for development

• Potential high placement accuracy, high throughput options:– Projected manufacturing requirements require new doping

concepts

– Exploratory approaches considered: • Directed self-assembly, such as Javey’s SAM delivery method

77

Deterministic Doping Workshop:Summary



• While deterministic doping options considered remain far from manufacturable, they are useful for understanding extensibility limits and exploring new device functionality.– Single Ion Implantation methods exhibit the potential for:

Achieving near 10 nm placement control Throughputs compatible with extensible device development

– SAM assisted shallow doping methods, with near nm placement control, enable device studies near the projected limits of charge based FET technology.

– STM based deterministic doping, with near atomic level placement control, provides a tool and methodology for exploring radical device concepts with novel functionality.

• Manufacturable deterministic doping options may integrate top down patterning with materials designed to deliver dopants deterministically and effect desired properties.

78

ERM for FEP: Key Deterministic Doping Messages for the 2009 ITRS Revision



InterconnectsYuji Awano & Sean King

• ERM for low impedance interconnects & Vias– CNTs– Nanowires– Graphene

• ERM for Low κ ILD– Macromolecules (Dan check with Scott List)

• Selective Etch & Deposition



2008 Interconnect

– General:• To ensure a meaningful comparison, standardize metrics for each application,

across the set of candidate materials, e.g. CNTs, graphene, and nanowires for interconnect applications

– Add Chris Case to the ERM Distribution list – Alternate channel materials:

• Focus on contact materials for Ge and III-V materials. • Contact resistance and S/D leakage are critical properties that need to be

addressed – CNTs for Interconnects:

– Separate this topic into via and planar interconnect applications – CNT interconnects must have a conductivity at least 2X greater than copper

• Graphene Interconnects: – Determine the width and layer thickness dependence of the conductivity

– Novel Barrier Layers:• Target barrier layer thicknesses of 1-2 atomic layers• It is imperative to realize low process integration complexity• Barrier material candidates must provide a good diffusion barrier to Cu



ERM Interconnect Scope: 20092007 Transition In Transition Out 2009

Nanotube Interconnects

Assess

Nanowire Interconnects

Assess

Nanotube Vias Assess

Nanowire Vias Assess

1-2 monolayer barriers

ERM Assess

Macromolecule Low K ILD

Need k<2.0

DSA Etch Transition? Status

DSA Selective Deposition

Transition? Status





• Most reports are for 20nm thick layers• Need to understand the mechanism• Explore ALD compatible options





10 100 10000

1

2

3

4

5

sidewall

grain boundary

bulk resistivity

Res

istiv

ity [µ

cm

]

Line width [nm]

Emerging Interconnect ApplicationsVias Multi-wall CNT Higher density Contact Resistance Adhesion

Interconnects Metallic Alignment Contact Resistance

Dielectrics Novel Polymer ILDs

Y. Awano, Fujitsu

H. Dai, Stanford Univ.

Quartz Crystal Step Alignment

Ref. 2005 ITRS, INT TWG, p. 22

ERMs Must Have Lower Resistivity

Cu











Assembly & PackagingNachiket Raravikar & Raja Swaminathan

• ERM for Thermal Heat Spreading using novel materials/structures

• Low Temperature Lead free Assembly for better reliability of electronic packages

• Chip to Package Electrical Interconnects• Controlled polymer properties

– Application– Process– Operation– Halogen Bromine Free– Multi-functionality

• High Performance Package Capacitors• Energy & Bio Application requirement & status will be

descriptive in 2009 (specific to packaging?)



2008:ERM WG - Assembly and Packaging ITWG:

• CNTs for thermal interface Applications: – Critical metrics: Low contact resistance and CNT density – Even though this technology is low on the learning curve and commercial viability

usually ranks as a low priority metric during the exploratory phase of research, researchers are encouraged to consider cost implications as one of several critical success factors for assessing the potential maufacturability of the CNT TIM;

• Insulating nanoparticles for package filler applications:– Add biocompatibility and assess cost implications

• Nanometal for chip attach applications:– Include the following additional families of requirements: melting point, electrical

conductivity, electromigration resistance, stress relief, inter-metallic formation, and properties, as needed, for predictive modeling.

• Macromolecules for polymer adhesion applications to different materials: – Add water absorption (free), CTE, modulus, bonding, and debonding

• Complex metal oxides: – Add dielectric constant at minimum thickness and charge leakage

• Assembly & Packaging Priorities for e-Workshops were: – Priority #1: Assembly & Package Dielectrics High and Low K materials– Priority #2: Nanocomposite moisture barriers and adhesion materials– Priority #3: Low temperature assembly materials & nanowires– Priority #4: Carbon Nanotube thermal Interface materials



ERM A&P Scope: 20092007 Transition In Transition Out 2009

Nanotube Electrical Interconnects

Status

Nano solders Status

Nanocomposite package polymers

Status

High density, high performance capacitors

Status

Nanotube thermal interface materials

Status

Low assembly temperature materials (ACF?)

Add to ERM (?) Status Ag Nano ACF

Nanowires for Power & Detectors

Add to ERM Status



ITRS 2008 ERM A&P Workshops: key learnings

Nachiket Raravikar & Raja, Yuji Awano

Intel Corporation

September 2008



• Title: CNT Interconnects & Thermal Challenges– Focus: Update the progress in assembly compatible integration &

contact resistance control of CNT for interconnect and thermal applications

– Teleconference [Apr-May’08]• Prof. Banerjee, UCSB [May’08]• Prof. Majumdar, UC-Berkeley [Aug’08]

Focus area 1: CNT

Organizer: Nachiket Raravikar



CNT TIM workshop summary

• The following two still remain challenges in CNT TIM applications:1. Controlling CNT array density

- Best density up to ~ 1010 – 1011/cm2 achieved by optimizing the catalyst under-layer thickness;

- It’s not clear what the target density should be and whether an array density higher than the above could be achieved

2. Increasing bonding or wetting of CNT with Si, SiO2 and metals to lower thermal interface resistance

- Lowest thermal interface resistance achieved by In coating of CNT:

Interfacial conductance [glass-In-CNT-Si]: 3.1±1.5 MW/m2∙K as compared to Glass-CNT-Si: 0.075±0.005 MW/m2∙K

- Issue of In wetting on CNT remain- Not many strategies exist on improving thermal interface

conductance between CNT-Si or CNT-metals- Realistic targets of experimentally achievable interfacial

thermal conductance need to be defined



CNT summary

The following has been achieved...• Low electrical contact resistance, close to theoretical value, has

been achieved experimentally• High frequency response of nanotubes (impedance, inductance, skin

effect) has been modeled and skin effect is predicted to be negligible

• Some progress towards achieving high density CNT arrays 1010 – 1011/cm2

• In-CNT interface shown to reduce thermal interface resistance

The following challenges or unknowns still remain...• Low T CVD growth of CNT• Increasing CNT array density• Reducing CNT electrical and thermal contact resistance•



• Title: Polymer nano-composites mechanical, rheological challengesFocus: 1. Adhesion: Update progress in interfacial adhesion control

between nanoparticles and matrix as well as between polymers and metals;

– 2. Multifunctionality: high toughness, low CTE, high/low modulus, flow properties etc. using nano-fillers;

– 3. Moisture diffusion barriers: block moisture diffusion for regular as well as MEMS packages

– Teleconference• Prof. Giannelis, Cornell [Aug’08]

Focus area 2: Polymer Nano-composites

Organizer: Nachiket Raravikar



Polymer Composite Properties

0102030405060708090

100

% Relative values

Viscosity SurfaceTension

CTE Modulus Tg

Mold Compound

Underfill

Adhesive



Macromolecules/nano-composites workshop summary

• Adhesion improvement with nano-composites– Adhesion enhancement is shown with nanocomposites, however the

mechanism is not well understood (nanoclay composite to Silicon)• Nano-composite mechanical property enhancement [modulus, CTE,

toughness, elongation]– Decoupling of properties (stiffness-toughness) is a very attractive

feature of nano-composites and has been demonstrated with various composite systems

– Hypotheses of toughening of nano-composites are in place: nano-particle migration to crazes to prevent crack propagation; hypothesis validation is not done yet

• Nano-composite moisture absorption– Relative permeability is shown to drop significantly at very small

volume fractions of nanoparticles [silicates]• Dispersion, interface tailoring of nano-fillers with polymer matrix

– Various surface chemistries demonstrated to improve dispersion of nano-silica (particles or clays) in composites: epoxy silica, amino silica, HMDS silica

– Dispersion issues still remain such as intercalation or exfoliation of clay or nano-particle clusters, delamination at filler-matrix interface



ERM for Low Assembly TemperatureNano-solders/ECA

• Nano-solders– < 10nm SnAg Melting point reduced to 194C

• Surfactant passivation required for oxidation prevention• Surfactants decompose and good solder joint forms with 230C reflow• Need to show good solder joints at lower reflow temperatures

– 10nm SnAgCu melting point reduced to 199C• Surfactant passivation required• Recrystallization temperature also reduced to 103C• Wettability improvement with rare earth dopants

• Electrically conductive adhesives– Lower temperature cure (< 200C) instead of reflow

• Ag flakes in epoxy resin– Isotropic (ICA)– Anisotropic (ACA)– Improved contact resistance with oxygen scavengers and corrosion inhibitors (Galvanic

corrosion established as main mechanism for reduced contact resistance)– Increased current carrying capability using liquid phase sintering and reducing agent

additions– Integrated self assembled monolayer improved adhesion– ECA with a higher shrinkage shows a higher conductivity– Conductivity can be improved by using multifunctional epoxy– Impact performance of ICA could be enhanced by elastomer-modified epoxy– Ag migration in ECAs could be dramatically reduced by monolayer protection– Challenges: Processability (Solidification, Voids, pressure, temperature, time control),

Electrical Performance: (Low current carrying capability, lack of self alignment), Reliability (High Moisture Absorption (low filler loading), High CTE, Reworkability, and identifying low cost fillers.



ERM ESH Needs (July ’08)M. Garner & J. Jewett

– Jim Jewett and Mike Garner agreed to write a white paper on NanoEHS needs to attach to the ITRS ESH & ERM chapters.

• Toxicology research integration and summary

– Dan Herr recommended that the ESH-ERM communities consider driving the energy and health related opportunities that are emerging from the ITRS Functional Diversification agenda.

• This may enable the ESH community to get ahead of regulation, as functional diversification may provide enabling energy and health opportunities and enable the industry to leap frog over, remove, and/or avoid emerging issues.



Key Issues

• Develop timelines for intercept commerce• Regulatory Processes

– What is the

• Research Timelines– Resolution of Acute & Chronic Issues– Klebosol example

• WSC (?)



Metrology NeedsYaw Obeng & Alain Diebold

• Korea ERM asked for Reference Material needs to be added



Metrology 2008

– The ERM – Metrology collaborative engagement continues to increase

– No new issues were identified by the ERM, except the need for nanoscale graphene characterization

– For example, Alain identified a number of new physical effects under study in graphene, including electron “puddling”.



Metrology

• Characterization of Domains and Domain Walls

• Characterization of Magnetoelectric coupling Coefficients in “leaky materials”– U. Of Nebraska: Ubert

• Imaging “soft” thin materials and differentiate structure (DSA & Resist)

• Characterizing random defect types– Software for defect recognition (KLA)



ERM Metrology Gaps and RequirementsERM Metrology Gaps and Requirements

Orientation, number of layers, grain structure

Nanoimprint: Stress, adhesion, interface strength, defect generation

EUV resist exposure mechanism



Modeling NeedsSadasivan Shankar



Modeling 2008

– The scope of the Modeling ITWG was discussed and its relationship with the ERM WG.

• While much of the ERM focus lies outside the current focus of the M&S ITWG, emerging materials will require considerable application related modeling that will serve as a bridge to the design community, i.e. compact models.

– More discussion is needed, especially with respect to :– ERM related metrology, compact models, application

specific material models, such as the dielectric constant of thin high-complex metal oxides and the unique domain structures of mixed phase segregated block copolymers.

– Modeling is needed to extract critical information from parallel metrology measurements and to decouple nanometer scale physical interactions

• This should topic be included in ERM – M&S discussions



Needs in Materials Modeling

• Extension to larger scales for equilibrium calculation and temperature dependence of properties and processes– Gaps in ability to model integrated systems

• Metallic systems specifically transition and inner transition metals. – Need specific functionals that could be tested with more rigorous

techniques,• More generalized extension for band gaps

– Currently hybrid and metal functionals are being developed but need to be thoroughly characterized

• Strongly correlated systems require model development to explain the interaction between spin, charge, and lattice changes for potential use in spin wave propagation. – Requires quantification of the energy associated with spin switching and

transport and the identification of speed limitations. • Extension or linking of quantum models from femtoseconds to

microseconds or longer to emulate realistic synthesis and transport.



Modeling Status

• Self Assembly Modeling is adequate for current needs– “Pattern generation” modeling is a gap for Design

• Resist Models are not predictive over a broad range of parameter space

• Nanotube Modeling Needs:– Synthesis modeling is helping understand effects

• Why is CNT growth density is enhanced on an oxide surface, but not a metal surface? (No understanding)

– No understanding of how zeolite structure controls nanotube chirality

– Need Modeling of CNT-metal contacts



Modeling Needs• III-V, Ge Modeling of the Semiconductor High K surface, and

interface growth (defects Ef pinning)• Graphene modeling (Electronic properties, interfaces and

transport)• Oxide modeling (Complex Oxides & Strongly Correlated

Electron State Materials)– Multi length & time scale modeling of physical phenomena (Spin,

Charge & orbital ordering, U)• Impact of local & long range symmetry on observed properties and

dynamics (Prediction of Macroscopic phase, properties, and behavior) • Role of defects in properties, phase segregation and behavior

– Heterointerface structure (reconstruction & electronic properties, U)• Role of defects in properties, phase segregation and behavior

– Nanoscale electronic phase segregation near phase transitions & in interfaces

• Effect of electric and Magnetic fields

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