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Challenges for Materials to Support Challenges for Materials to Support Emerging Research DevicesEmerging Research Devices

C. Michael Garner*, James Hutchby+, George Bourianoff*, and Victor Zhirnov+

*Intel CorporationSanta Clara, CA+Semiconductor Research CorporationResearch Triangle, NC

C. Michael Garner*, James C. Michael Garner*, James HutchbyHutchby++, George Bourianoff*, and , George Bourianoff*, and Victor ZhirnovVictor Zhirnov++

*Intel Corporation*Intel CorporationSanta Clara, CASanta Clara, CA++Semiconductor Research Semiconductor Research CorporationCorporationResearch Triangle, NCResearch Triangle, NC

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Key MessagesKey Messages• Silicon Nanotechnology is production reality

and follows Moore’s law• New materials are needed for future

technologies• Materials research is crucial for revolutionary

devicesSynthesisMetrology & CharacterizationModeling

• New materials will require collaboration

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AgendaAgenda

• Moore's Law• Extending CMOS• Revolutionary CMOS• Beyond CMOS• Summary

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Silicon Technology Reaches Silicon Technology Reaches NanoscaleNanoscale

MicronMicron

1000010000

10001000

100100

1010

1010

11

0.10.1

0.010.01

NanoNano--metermeter

NanotechnologyNanotechnology(< 100nm)(< 100nm)

130nm130nm

90nm90nm

70nm70nm50nm50nm

Gate LengthGate Length 65nm65nm

35nm35nm

19701970 19801980 19901990 20002000 20102010 20202020

45nm45nm32nm32nm

22nm22nm

25nm25nm18nm18nm

12nm12nm

0.7X every 2 years

Nominal feature sizeNominal feature size

Source: Intel

MicronMicron

1000010000

10001000

100100

1010

1010

11

0.10.1

0.010.01

NanoNano--metermeter

NanotechnologyNanotechnology(< 100nm)(< 100nm)

130nm130nm

90nm90nm

70nm70nm50nm50nm

Gate LengthGate Length 65nm65nm

35nm35nm

19701970 19801980 19901990 20002000 20102010 20202020

45nm45nm32nm32nm

22nm22nm

25nm25nm18nm18nm

12nm12nm

0.7X every 2 years

Nominal feature sizeNominal feature size

Source: Intel

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IntelIntel’’s Transistor Research ins Transistor Research inDeep Nanotechnology SpaceDeep Nanotechnology Space

65nm process65nm process2005 production2005 production

30nm30nm20nm20nm

45nm process45nm process2007 production2007 production 32nm process32nm process

2009 production 2009 production

15nm15nm

Experimental transistors for future process generationsExperimental transistors for future process generations

22nm process22nm process2011 production 2011 production

10nm10nm

Transistors will be improved for production

Transistors will be improved for Transistors will be improved for productionproduction

Source: IntelSource: Intel

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Nanotechnology Eras Nanotechnology Eras

ReasonablyFamiliar

NanotubesNanowires

ReallyDifferent

2005

11 yrs.

0.001

0.01

0.1

2000 2010 2020

micron

1

10

100

nm

45 nm65 nm

32 nm22 nm

16 nm

11 nm8 nm

Generation

LGATE

Evolutionary CMOS Exotic

Revolutionary CMOS

2003, M. Bohr

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Revolutionary CMOSRevolutionary CMOS

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• Options for sub 20nm technologies• Challenges: Placement and property control

NanomaterialNanomaterial TransistorsTransistors

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1D Revolutionary CMOS Critical 1D Revolutionary CMOS Critical PropertiesProperties

• Critical Synthesis Issues• Critical Materials Properties

Device MaterialDensity of States as manifest in Eg, effective mass & μ

Gate DielectricDielectric constant

• Critical Interface propertiesBand Offset (Work function, fixed charge, trapped charge)No Fermi level pinningLattice constant & coefficient of thermal expansion

Gate

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Characterization & Modeling Characterization & Modeling ChallengesChallenges

• How do you know the material is “good” ??• Measurement of Properties

Structure and composition (nm scale)Electronic properties & interactions with interface materials

• Impurities & Defects• Modeling of Electronic Properties

Density of States, effective mass, EgModels of interfaces, stress effects, etc

New Metrologies & Models Needed!!!!New Metrologies & Models Needed!!!!New Metrologies & Models Needed!!!!

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ExoticExotic……

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Exotic: What are we looking for?Exotic: What are we looking for?• Required characteristics:

ScalabilityPerformanceEnergy efficiencyGainOperational reliability Room temp. operation

• Preferred approach:CMOS process compatibilityCMOS architectural compatibility

Alternative state variables• Spin–electron, nuclear,

photon• Phase • Quantum state• Magnetic flux quanta• Mechanical deformation• Dipole orientation• Molecular state

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Device Operation & Critical PropertiesDevice Operation & Critical Properties

• At least 2 “stable” states• Mechanism to change states

Communication with CMOS: Voltage or ChargeLogic:

Ability to change the states of other identical devicesGain

• Mechanism to read statesAbility of CMOS to read the states (voltage or charge)

• Material properties may limit mechanisms

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Alternate State Variable ExamplesAlternate State Variable Examples

• Molecular State• Electron Spin

Spin Injection in semiconductorsFerromagnetic semiconductors

• Orbitronics (Multiferroics)

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Molecular MaterialsMolecular Materials

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Molecular StateMolecular State

• Fabrication of contacts is challenging• Need better understanding of mechanisms

O2NO2N

NH2NH2

AuAu

SS

AuAu

Critical Material PropertiesTransconductance change -Change in Tunnel distance-Delocallization-Locallization of states-Collective conformational changes-Charge Storage

Critical Material PropertiesTransconductance change -Change in Tunnel distance-Delocallization-Locallization of states-Collective conformational changes-Charge Storage

Critical Interface PropertiesAtomic energy levels in resonance with the molecular energy states-Work Function-Contact material DOS

Critical Interface PropertiesAtomic energy levels in resonance with the molecular energy states-Work Function-Contact material DOS

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Characterization & Modeling Characterization & Modeling ChallengesChallenges

• How do you know you have a “good” device??• Measurement of Properties

Structure & contact interactionElectronic energy levels & interactions with interface materials

• Modeling of Electronic PropertiesDensity of States, effective mass, EgModels of interface electronic interactions Charge storage, excited local states, conduction mechanismsAccurate prediction of energy levels for molecular structures

New Metrology & Models Needed!!!!New Metrology & Models Needed!!!!New Metrology & Models Needed!!!!

O2 N

O2 N

NH

2N

H2

Au

AuSSAu

Au

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SpintronicSpintronic MaterialsMaterials

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Semiconductor Semiconductor SpintronicsSpintronics

Critical Materials PropertiesSemiconductor:•Spin Orbit Coupling (As manifest in spin lifetimes, and diffusion lengths)•g-Factor

Ferromagnetic contact source: •Coercivity

Critical Materials PropertiesSemiconductor:•Spin Orbit Coupling (As manifest in spin lifetimes, and diffusion lengths)•g-Factor

Ferromagnetic contact source: •Coercivity

Interface Critical Properties•Interface Band Structure Matching [energy & symmetry] (as manifest in spin injection efficiency) •No band-bending

Interface Critical Properties•Interface Band Structure Matching [energy & symmetry] (as manifest in spin injection efficiency) •No band-bending

How can we separate materials issues??How can we separate materials issues??

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Ferromagnetic Semiconductor Ferromagnetic Semiconductor SpintronicsSpintronics

Critical Interface Properties•Spin Orbit Coupling as manifest in (Interface Magnetic Anisotropy)•Minimal band bending

Critical Interface Properties•Spin Orbit Coupling as manifest in (Interface Magnetic Anisotropy)•Minimal band bending

Critical Material Properties•Spin Exchange Interaction •Exchange Splitting Energy•T curie•Moment per atom

Critical Material Properties•Spin Exchange Interaction •Exchange Splitting Energy•T curie•Moment per atom

How can we separate materials issues??How can we separate materials issues??

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nm Scale Material Diagnosticsnm Scale Material Diagnostics

• Need new metrology to measure spin properties & interactions at nm scale

Spin polarization, lifetimes, diffusion lengthsSpin interaction with interface band bending, roughness, states Local electric & magnetic fieldsStress interactions with spin lifetimes

hνhν

HH

KPM, MFM, etcKPM, MFM, etc

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Spin Material Modeling NeedsSpin Material Modeling Needs

• Interaction of spin lifetime and diffusion lengths with:

DefectsBand bendingStressInterfacial roughnessInterface states and defectsSpin injection processes

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OrbitronicsOrbitronics & & MultiferroicsMultiferroics

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PerovskitePerovskite MaterialsMaterials

• Ferroelectrics• Ferromagnetics• Multiferroics (Ferroelectric & Ferromagnetic)• Colossal Magnetoresistance• Semiconductors• High-T Superconductors• Promising optical properties• Phononic properties

• Ferroelectrics• Ferromagnetics• Multiferroics (Ferroelectric & Ferromagnetic)• Colossal Magnetoresistance• Semiconductors• High-T Superconductors• Promising optical properties• Phononic properties

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MultiferroicsMultiferroics

• Interplay between charge, orbital, and spin degrees of freedom

• Magnetic field control of ferroelectric polarization

• Switching of magnetic polarization induced by electric fields

H applied

σ

EE

H E

Conceptual Conceptual

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OrbitronicsOrbitronics

• Orbitronics: Perovskite manganese oxidesRBaMn2O6

R=Sm, Eu, Gd, Tb, Dy, Ho, Y

H appliedEE

H E

Conceptual Conceptual

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ChallengesChallenges

• Key PropertiesPiezoelectric, Multiferroic, Colossal MagnetoresistanceStress can interact with multiferroic properties

• Good News: Multiferroic & CMR• Bad News: Piezoelectric (Properties Depend on

stress)• Material unknown

Vacancies, interstitials and impurities can cause local stressHow pure and defect free do the materials need to be?Integration Issues: Coefficient of Thermal Expansion (CTE)

StressStressStressStress Δ EΔ E

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New Metrologies NeededNew Metrologies Needed

• Nanometer characterization of:Piezoelectric propertiesElectro & Magneto-optical propertiesFerroelectric and Ferromagnetic propertiesVacancy, defect, impurity interactions Local stress effectsInterface properties

HH

AFM, KPM, MFM, etcAFM, KPM, MFM, etc

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MultiferroicMultiferroic Modeling NeedsModeling Needs

• Basic models of the relationship between structure, bonding, and the resulting properties

Extend from local structure to extended propertiesModels of defect and vacancy impact on structure and properties

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Special nm Metrology NeedsSpecial nm Metrology Needs

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nm Scale Material Diagnosticsnm Scale Material Diagnostics

• Atomic structure of carbon based materialsLow energy TEM

• Modeling of nm probe interactions with materials Improve analysis of signals from AFM based and multi-probe metrologies

hνhν

HH

KPM, MFM, etcKPM, MFM, etc

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SummarySummary• Silicon Nanotechnology is production reality

and follows Moore’s law• New materials are needed for future

technologies• Materials research is crucial for revolutionary

devicesSynthesisMetrology & CharacterizationModeling

• New materials will require collaboration Gov’t, Universities, Research Institutes, & Industry

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For further information on Intel's silicon technology and Moore’s Law, please visit the Silicon Showcase

at www.intel.com/research/silicon