Frontiers of High Throughput Material Science In... · 2010-06-04 · Frontiers of High Throughput...

© 2010 IBM Corporation

IBM Research

Frontiers of High Throughput Material Science

C. Lavoie, J. Jordan-Sweet, Conal Murray, Simone Raoux,B. Yang and Team…

BNL/NSLS-II Workshop May 27, 2010 © 2010 IBM Corporation


SummaryBackground and Challenge:

Reduction trends Increasing importance of materialsFeature size now Increasing importance of surface/interfaces

IBM Current Synchrotron Capabilities: In situ phase formation during annealingFull texture determination and phase identification through pole figure measurements

Example – Contacts to Si CMOS devices:Moving from yield to performance oriented integrationImportance of measuring in relevant dimensions

Future more problems in sightNeed for faster and easy to use characterization/optimization toolsAutomation and remote access



1995 2000 2005 2010 201510

100

1000

19971999

2002

Pre

dict

ed G

ate

Leng

th (n

m)

Year of Production

2004-2007

1994

End of Classical Scaling

Scaling now decreases performance

Performance gains now through innovations

and materials improvements

Evolution of PredictionsGate Width

0.01 0.1 1Gate Length, Lgate (um)

0.1

1

10

100

1000

classic scaling

Tox (C)

Vdd (V)

30 nm



S=S1-S0

S0

S1

2θ

χ

ϕ

θ

Synchrotron X-Ray DiffractionIn Situ during annealing Full texture determination

Pole figure Measurements

Linear detector

640 simultaneous

measurementsNSLS

Beamline X20C

Lock-in #1

Lock-in #2HeNeLaser

Measurement and Control Electronics

Sample

LinearX-ray Detector

AnnealingChamber

FocusingMirror

MultilayerMonochromator

AnalysisWorkstation

ExperimentControl

BeamlineControl

Laser

1013 photons/s - 104 gain

Can measure up to 4 samples/ hour28 000 measurements over the past 15 years



300

400

500

600

700

800

900

250 180 130 90 65 45 32 22 15

Technology Node (nm)

Con

tact

For

mat

ion

Tem

pera

ture

(C)

30 nm

IBM Device Contact Evolution

C54-TiSi2

NiSi and NiPtSiLow temperature formation Ni diffusion

But low temperature agglomeration (<600C) Stabilization through Pt additions and I/I

CoSi2 - Important Si diffusionExtreme sensitivity to oxygen

1

10

100

1000

Res

ista

nce

(arb

. uni

ts)

25 30 35 40 45 50 55 60 65Poly-Si Gate Width

CoSi 2

NiSi

100 nm100 nm100 nm Vacancies in SiVoid formation for size < 50nm

NiPtSi+ interface engineering

for reduction of contact resistivity

Temperature ( °C)

Scat

tere

d In

tens

ity o

r R

esis

tanc

e ( a

rb. u

nits

)

Ti(101))

50

45

40

600 800 1000

Diff

ract

ed A

ngle

2θ(d

eg)

400

Resistance

Light Scattering - 0.5 μm

Light Scattering - 5 μm

0

1

2

C54(311)

C49(131))

Ti(002)

C54(040)

TiSi2

C54 TiSi2C49 TiSi2

Transformation

Lines

Smaller areas

BlanketFilms

800 C

930 C

930 C

C54-TiSi2 Nucleation Limited for < 0.25 um.

Fixed through alloyingwith Nb or Ta

Light Scattering5 um

LS0.5 um

Resistance

NiSi (103) Pole Figure

(b)

1 μm

Ni alloy - Si

Poly-Si

(b)

1 μm

Ni alloy - Si

Poly-Si

(a) Pure NiSi

Si(100)

(a) Pure NiSi

Si(100)

Axiotaxy

Alloying for increasedthermal stability

ITRS predicted end of NiSi



YIELD / RELIABILITY

Maintain Film Morphology Reduced film thickness

Reduced dimensions

Reduce defectivity1. Thermal instability

axiotaxy

2. Encroachment fast diffusion of Ni on defects

3. Presence of theta phase in sequence Roughness / fast growth of NiSi

4. Formation stress defects Roughness in localized volumes

Nickel Silicide Optimization



YIELD / RELIABILITY


Reduced dimensions


axiotaxy




(103) Pole Figure

NiSi onPoly-Si

NiSi onSi(100)

55 nm 110 nmNickel Silicide Optimization



YIELD / RELIABILITY


Reduced dimensions


axiotaxy




Si<110>

Standard Si orientation 45o wafer rotationDiffusion on DISLOCATIONS

Diffusion on EOR Defects




YIELD / RELIABILITY


Reduced dimensions


axiotaxy




50

54

58

200 400 600 800

Tw

o T

heta

( °)

Temperature ( °C)

62

Ni

NiSiδ-Ni2Si (020)

δ-Ni2Si (013)

θ-Ni2Si (110)

3 °C/s in He

Phase Sequence – 10 nm Ni / SOI

Ni

Ni2Si

θ

RoughnessExample: 100 nm Ni / Si(100)




YIELD / RELIABILITY


Reduced dimensions


axiotaxy




Si

Ni

Ni2SiCompression

NiSi

Compression




Ni Alloys

Ag

CuCo

CdPd

NiTi

Zr

Hf

V

Nb

Ta

Cr

Mo

W

Mn

Tc

Re

Fe

Ru

Os

Rh

Ir Pt Au

Zn

Hg

B

Al

Ga

In

Tl

C

Si

Ge

Sn

Pb

Limit Axiotaxy

Retard Agglomeration

Pure NiSi NiSi with Pt

Pole Figures

60

55

50

60

55

50

60

55

50

200 400 600 800

Diff

ract

ed A

ngle

2θ

(deg

)

Temperature ( °C)

Pure Ni

Ni 5 % Pt

Ni 10 % Pt

Retard NiSi2 Formation



YIELD / RELIABILITY


Reduced dimensions


axiotaxy




Silicide Optimization

DEVICE PERFORMANCE

ITRS 2009

Silicide to Si Contact resistivity ultimately becomes the dominant component of the overall parasitic resistance.

Reduction of this contact resistivity requires:

1. Max dopant concentration in Si

2. Reduction in barrier heights through substrate or contact modifications

3. Possible use of Schottky contacts (also used for junctions)?

SHIFT



Φb : Schottky barrier height

N : Dopant density

ρc ~ exp [ ( ΦB) / (N)1/2 ]

Contact Resistance – RC

In most measurements, RC part of overall resistance

Other R elements are known RC inferred

Silicide Rs

Rc

R s/d R sp, R ext, Rov

Ec

Ev

EF



Barrier Heights – Metal Silicides Binary compounds

0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

YbSixErSi2

DySi2LuSixGdSi2TbSix

HoSi2YSi1.7

ScSiHfSi

ZrSi2MoSi2TaSi2CrSi2TiSi2

NbSi2VSi2

CoSi2MnSiNiSi

WSi2Ni2SiNiSi2

MnSi1.FeSi2CoSiRhSi

Pd2SiRu2Si3

ReSi2Pt2Si

PtSiIr2Si3

O sSi1.IrSi

IrSi3

TM

or

RE

Sili

cide

Barrier Height to n-Si

p-FET

n-FET

Variations betweenauthors

Effect of 3 A oxide

• Process window established and contact R tested• NiPt silicide can be engineered to ~ 50 meV of band edge



Φb : Schottky barrier height

N : Dopant density

ρc ~ exp [ ( ΦB) / (N)1/2 ]

How about sizes and texture?

In most measurements, RC part of overall resistance

Other R elements are known RC inferred

Silicide Rs

Rc

R s/d R sp, R ext, Rov

Ec

Ev

EF



Type of texturesRandom texture Fiber texture

Axiotaxial texture Epitaxial texture

NiSi

plan 110

101 ou 211

Si

Random orientation around the

normal

Random orientation around the

normal

C. Detavernier et al, Nature 426, 641-5 (2003) MOST STABLE FILM



Highly Anisotropic Material

• Different interface orientation have different diffusion behavior and Schottky barriers

• Huge anisotropy may cause grain growth, voiding and texture changes

• Different texture components will have different agglomeration and stressing behaviors

D.F. Wilson, O.B. Cavin, Scr. Metall. Mater. 26, 85 (1992) C. Detavernier et al. J. Appl. Phys. 93, 2510 (2003)D. Connétable, O. Thomas, Phys. Rev. B. 79, 094101 (2009)

c = 5.66 Å

b = 3.26 Åa = 5.23

Å

Young’s Modulus

b-axis shows thermal contraction

Coefficient of thermal expansion (10-6 )

a + 42b - 43c +34

Ni

Si



Recent DevelopmentsFull texture determination

Analysis and Fitting softwareFull fit of all planes and diffraction angles

S=S1-S0

S0

S1

2θ

χ

ϕ

θ

Linear detector

640 simultaneous

measurements

dCylinder or video

of pole figure

Ni or PtSi

a

b

c

xy z

013

cb

Unambiguous phase indexationand grain orientation:

Ni-Pt / Si-Ge

6 hours 640 pole figures



Recent DevelopmentsNew Test Site - large enough for xray beam

• (~3 x 5 mm chiplets various dimensions reaching below 30 nm)

PHASE FORMATION STRESSTEXTURE

Width = 75 nmSpace = 55 nm Length = 500 nm

pitch = 130 nm

SiO2

500 nm

130 nm

130 nm

Tilted view SEM

Silicide phase formation temperature increases for decreasing linewidths.



NiSi texture in nano-dimensions

22 nm blanketNiSi

22 nm blanket (Ni 5%Pt) Si

~10 nm (Ni 5%Pt) Si27nm Line Width

AXIOTAXY FIBER TEXTURE AXIOTAXY

Pt was used to eliminate axiotaxy in NiSi. With narrow dimensions, axiotaxy returns



Requirements for the FutureMicroelectronics Industry

Applicable to wide range of materials

Fast acquisition and analysis must get more in shorter timeLess access time

Shorter learning cycles

Straightfoward Techniques and AnalysisMultiple potential users if learning/analysis is rapid

Timely accessNeed to solve problems as they appear. Regular window for access.

Remote AccessIBM Research world wide.

Regular web access train more engineers.



X20C upgrade → CLS Brockhouse and NSLS-II

Three in-situ probes in real time: resistivity, XRD and light scatteringRobotic sample changing, automated pumpdown and purge with purified gasesRapid thermal annealing up to 1100ºC

fast linear detector for phase transformations MMPAD area detector for fast texture evolution640 pixels, 80mm long 512x256 pixels, 107 max cps 108 dynamic range, 30 msec readout 20-500 fps (1.5 msec readout)

Matlab script analysis: integrated or peak-fitted regions vs temperature or time, derivatives for transition temps, Avrami analysis, conversion of pole figures to ODF?

tie-in to PDF files for phase ID?

Time-resolved XRD for phase transformations and texture evolution in thin films and nanostructures

θflange clampingapparatus, slidesin and out to remove flange on chamberfor sample changing

chamberadded partialchi arc

2 rails for guiding flangeclamping apparatus

2θ

C. Lavoie, R. Wisnieff, C. Cabral, J. Jordan-Sweet, K. Rodbell



SummaryBackground and Challenge:

Reduction trends Increasing importance of materialsFeature size now Increasing importance of surface/interfaces

IBM Current Synchrotron Capabilities: In situ phase formation during annealingFull texture determination and phase identification through pole figure measurements

Example – Contacts to Si CMOS devices:Moving from yield to performance oriented integrationImportance of measuring in relevant dimensions

Future more problems in sightNeed for faster and easy to use characterization/optimization toolsAutomation and remote access

Frontiers of High Throughput Material Science In... · 2010-06-04 · Frontiers of High Throughput...

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Transcript of Frontiers of High Throughput Material Science In... · 2010-06-04 · Frontiers of High Throughput...