Landscape of materials design Landscape of materials design for - - PowerPoint PPT Presentation

National Institute for Material Science

Landscape of materials design Landscape of materials design for future for future nano nano electronics electronics And And high high-

• throughput materials

throughput materials exploration exploration

Toyohiro Toyohiro Chikyow Chikyow Advanced Electric Materials Center, Advanced Electric Materials Center, National Institute for Materials Science National Institute for Materials Science

2008.3.5 2008.3.5-

• 7 JST

7 JST-

• DGF

DGF Nano Nano Electronics Electronics Seminor Seminor at at Achen Achen

T.Nagata T.Nagata1

1, N.Umezawa

, N.Umezawa1

1, M.Yoshitake

, M.Yoshitake1

1,

, National Institute for Materials Science (NIMS) National Institute for Materials Science (NIMS) K.Ohmori, K.Ohmori,3

3, T.Yamada

, T.Yamada3

3,

, Waseda Waseda University University

• H. Watanabe
• H. Watanabe4

4 ,

, Osaka University, Osaka University, K.Shiraiishi K.Shiraiishi 5

5 5 5Tsukuba University,

Tsukuba University,

• H. Koinuma
• H. Koinuma1, 2

1, 2

Japan Science and Technology Agency (JST), Japan Science and Technology Agency (JST),

Contents Contents 1) 1)New Materials and High Throughput New Materials and High Throughput Materials Exploration Materials Exploration 2) 2)Example 1: Gate oxide research Example 1: Gate oxide research 3) 3)Example 2 :Metal gate research Example 2 :Metal gate research 4) 4)Materials informatics Materials informatics 5) 5)Summary Summary

Work function measurement Surface analysis

Beyond CMOS new logic new memory (Spintronocs,quantum system)

Present CMOS high high-

• k

k、 、metal metal gate,Low gate,Low-

• k

k Nano Electronics

Lithography

Silicon technology High speed, power saving and functionality High speed, power saving and functionality Nanotechnology More-Moore More More-

• Than

Than-

• Moore

Moore

Ultimate CMOS Ultimate CMOS ( (nanowire nanowire, , nanosheet nanosheet) )

N e w f u n c t i

• n

a l i t y

• n

S i O p t i c a l d e v i c e , s e n s

• r
• r

g a n i c 3 D C M O S （ F i n , S G T ）

New channel CMOS (Ge, III-V materials )

Nano characterization Development of ultra small, super power saving, high efficiency multi function by integration with Si device technology and nano technology

New materials exploration by combinatorial methodology Aiming at ultra small, super power saving, high efficiency multi functional device

Research Trend in Research Trend in Si Si nano nano device device

30nm

Present Present Si Si nano nano device device ( (hp65nm node is completed) hp65nm node is completed)

New Materials New Materials based based Si Si device device ( ( hp32 hp32-

• 22 nm node )

22 nm node )

Materials Materials Exploration for Exploration for Nano Nano device device High High-

• k ,metal gate,

k ,metal gate, Nano Nano wires ( wires ( Si Si CNT or others CNT or others interconnection interconnection ets ets Postscaling Postscaling generation generation ・ ・ Mixning Mixning technology technology

• f top down and bottom up
• f top down and bottom up

・ ・ 3D 3D nano nano structure structure ・ ・ Variety of Variety of nano nano interface interface 3D 3D nano nano structures structures

High speed operation High speed operation、 、High High denisty denisty packing packing、 、multi multi – –function device function device Si,Al Si,Al, SiO , SiO2

2 have been the major materials

have been the major materials

Prof.Endo Prof.Endo Tohoku Univ. Tohoku Univ.

National Institute for Material Science

SiO SiO2

2

Poly Poly Si Si Si Si HfSiON HfSiON HfLaON HfLaON LaAlO LaAlO3

3

La La2

2O

O3,

3,SiO2

SiO2

TiN,TaN TiN,TaN, , NiSi NiSi Ru,W,Mo Ru,W,Mo TaC TaC SiGe SiGe, , Ge Ge, , GaAs GaAs Graphen Graphen, , CNT, CNT, Si Si wire wire +Strain +Strain

New Materials in Future ULSI New Materials in Future ULSI 1) Collaboration 2) HT Experimentation 2) HT Experimentation

“ “Combinatorial solid Combinatorial solid-

• state chemistry of inorganic materials

state chemistry of inorganic materials” ”

Hideomi Hideomi Koinuma Koinuma and Ichiro Takeuchi, Nature Materials 3, 429 and Ichiro Takeuchi, Nature Materials 3, 429 -

• 438 (2004)

438 (2004)

High-Throughput synthesis：imitation to innovation

Combinatorial Chemistry Combinatorial Chemistry

Former Former combi combi system for inorganic materials system for inorganic materials

Innovative thin film technology Innovative thin film technology

Jingsong Wang et al Science 1998 March 13; 279: 1712-1714

What is combinatorial materials exploration? Discovery of new fluorescent materials 22 (4) 24 (16) 26 (64) 28 (256) 210 (1024) Ambient light UV irradiation

Combinatorial Materials Exploration and Technology

Combinatorial automatic ternary and binary Combinatorial automatic ternary and binary Composition spread synthesis system Composition spread synthesis system with Moving Mask System with Moving Mask System

Substrate Moving Mask

0.2 nm

Schematics of binary composition spread film

1) Deposition of Material A 2) Deposition of Materials B ~6 mm 3) Continuous composition spread in 1 atomic layer 4) Complete continuous composition spread film

Stepping Motor Stepping Motor 1 1 Stepping Motor Stepping Motor 2 2 Stepping Motor Stepping Motor 3 3 Control Box Control Box Control Board Control Board Sample Rotation System Sample Rotation System Mask Moving System Mask Moving System Targets Exchange System Targets Exchange System

Sample Heating System Sample Heating System Sample Holder Sample Holder

Concept of ternary materials combinatorial synthesis Concept of ternary materials combinatorial synthesis

Heater Box Heater Box

KrF KrF Eximer Eximer Laser Laser

Pulsed laser deposition (oxides, high-k films) Ion sputtering (metal gate materials)

Combinatorial deposition systems (@NIMS) Ion beam Targets Moving mask Sample Ar+ ion: 5 keV Iion ~ 40 μA

② ② Experiment design Experiment design ① ① Predict Predict （ （Calculation, Data base Calculation, Data base） ）

New materials discovery loop New materials discovery loop

④ ④ Date handling in Date handling in informatics informatics B X A

Materials for Materials for thermometer thermometer Oxide Oxide Magnetic Magnetic materials materials Sencor Sencor materials materials

③ ③ Combi synthesis Combi synthesis ④ ④ High throughput High throughput Characterization Characterization ⑤ ⑤ Starting another PJ Starting another PJ

Example 1 :Gate oxide Example 1 :Gate oxide Requirement Requirement 1) Higher dielectric constant 1) Higher dielectric constant 2) 2)Amorphous structure Amorphous structure

Defect density in Oxide (1) Ionicity : Y2O3< HfO2、MgO< TiO2, Al2O3 < ZnO<SiO2 (2) Valency : Y:3+, Hf:4+, Al:3+ Zn :2+, ：simple ; Ti 3+, 4+ : mixed

Sun, Zachariasen Glass empirical rule

Network former

( Can be amorphous for itself )

Intermediate oxide (Can be amorphous with Network forming oxide and modifier ) Additional oxide

( can be amorphous with network forming oxide )

Ternary alloying is inevitable for HfO2 to be amorphous Ternary alloying is inevitable for HfO2 to be amorphous Al2O3 Y2O3

HfO2

HfO2:Y2O3

HfO2 monoclinic (111)

_

(200)(020) (002) (222) Y2O3 cubic ( 1 1 1 )

• r

( 2 2 2 ) HfxY(1-x)O(3+x)/2 cubic

HfO2 Y2O3 Al2O3

Combinatorial X-ray Diffraction System

( Developed by Dr.Watanabe Dr.Fujimoto , AML-NIMS)

CombiXRD CombiXRD (Bruker: (Bruker: D8 Discovery D8 Discovery System ) System )

HfO2-Y2O3-Al2O3 system

HfO2(monoclinic) Hf2xY(2-2x)O(3+x) (cubic) (1) Dielectric constant mapping (2) Crystal structure mapping high-ε & amorphous region

HfO2 Y2O3 Al2O3

Tsub = 300℃, laser power = 3J/cm2, PO2 = 1e-6Torr, post-annealed at 700℃

Micro Structure Characterization for Combinatorial Samples Micro Sampling Method

Hitachi FB-2000 +Micro sampling Unit JEOL 4000EX (NIMS) H-9000NAR (T.I.T)

Al2O3 Y2O3 HfO2

FFT result

Si-sub. HfO2 Silicate

FFT result

Si-sub. Silicate HfO2-Al2O3

FFT result

Si-sub. Silicate HfO2-Y2O3-Al2O3

Characterizations of the combinatorial specimens Dielectric Dielectric Mapping Mapping by C by C-

• V, I

V, I-

• V

V

Structure mapping Structure mapping by Combinatorial XRD by Combinatorial XRD Interface structure mapping by TEM Interface structure mapping by TEM

Example 2 : Metal Gate Example 2 : Metal Gate Requirement Requirement 1) Work function tuning 1) Work function tuning 2) 2)Interface control Interface control 3) 3) Amorphous structure Amorphous structure

National Institute for Material Science National Institute for Material Science

Challenge of metal gate issues in Challenge of metal gate issues in hp hp32 32-

• 22nm node

22nm node

16 16-

• 10nm

10nm

Poly metal gate Poly metal gate

1) 1) interface roughness interface roughness 2) 2) Work function Work function fractuation fractuation 3) Edge roughness 3) Edge roughness

Metal glass gate Metal glass gate

Work functions of various metals Work functions of various metals

vacuum vacuum level level n+ Poly-Si (nMOS) p+ Poly-Si (pMOS) conduction band valence band 4.05eV 5.17eV 1.12eV 1.12eV

Nb:3.99 Nb:3.99-

• 4.3

4.3 Al:4.06 Al:4.06-

• 4.2

4.2 Ta:4.12 Ta:4.12-

• 4.25

4.25 Zr:3.9 Zr:3.9-

• 4.05

4.05 V:4.12 V:4.12-

• 4.3

4.3 Ti:3.95 Ti:3.95-

• 4.33

4.33 TaN:3.9 TaN:3.9-

• 4.25

4.25 Co:4.41 Co:4.41-

• 5.0

5.0 W:4.1 W:4.1-

• 5.2

5.2 Mo:4.3 Mo:4.3-

• 4.6

4.6 Os:4.7 Os:4.7-

• 4.83

4.83 Cr:4.5 Cr:4.5-

• 4.6

4.6 Ru:4.60 Ru:4.60-

• 4.71

4.71 Rh:4.60 Rh:4.60-

• 4.71

4.71 Au:4.52 Au:4.52-

• 4.77

4.77 Pd:4.8 Pd:4.8-

• 5.22

5.22 Ni:4.5 Ni:4.5-

• 5.3

5.3 WN WNx

x, TIN

, TINx

x

silicides:4.2 silicides:4.2-

• 5.0

5.0 Re:4.72 Re:4.72-

• 5.0

5.0 Ir:4.72 Ir:4.72-

• 5.0

5.0 Pt:5.32 Pt:5.32-

• 5.5

5.5 RuO RuO2

2:4.9

:4.9-

• 5.2

5.2

For nMOS For pMOS Threshold voltage Threshold voltage ± ±0.5V larger than 0.5V larger than poly poly-

• Si!

Si! Work Functions Work Functions ( from Dr.Takagi Data ) ( from Dr.Takagi Data )

Thermal reaction with HfO Thermal reaction with HfO2

2

Al Zr Ti V Nb Ta W Ru Pt Si minimal ΔG reaction (KJ/mole)

200 400 600 800 1000 1200 1400

least stable most stable

Metal Minimal Gibbs free energy

• f reaction (KJ/mole)

Al 33.42739 Zr 48.556 Ti 61.724 V 279.854 Nb 304.396 Ta 323.8836 W 554.42 Ru 835.599 Pt 1255.189 Si 231.836

Work Function variation Work Function variation with compostion spread film with compostion spread film of Pt

• f Pt-
• W

W

Thickness Thickness :10 nm :10 nm

W Pt Work Function

20 40 60 80 100

32 34 36 38 40

X-Position(mm) W or Pt/(W+Pt) (%) Work Function (eV)

4.4 4.6 4.8 5.0 5.2 5.4 5.6

( ) ( )

0.8 eV

Pt Pt W W Pt Pt

Forming gas annealing and/or

• xidizing gas annealing

CV measurements HfO2/SiO2/p-Si, La2O3/p-Si

Experimental

XTEM 60 nm p-Si W W-Pt ~40 capacitors in 8 mm Pt Deposition of Pt-W composition spread films with contact mask for capacitor electrodes

FGA (H2/N2, 5% H2): 300-450ºC OGA (O2/N2, 0.1% O2): 250-350ºC HfO2 (6 nm)/SiO2 La2O3 (7 nm)

Stacking structure

HfO2: MOCVD La2O3: E-beam evaporation

Pt-W alloy/p-Si XRD XPS Composition Work function Crystal structure Electric properties Pt-W (6nm)/HfO2/SiO2/p-Si HXPES (6keV, SPring-8) Composition Depth profile

Comparison of CV curves from HfO2 films under different annealing conditions Δ Vfb < 0.1 V Δ Vfb = 0.3 V

Relative dielectric constant: ε = 18.0.

0.8 0.6 0.4 0.2 Normalized capacitance

• 1.0

0.0 1.0 Voltage (V)

RPt ~ 1 (Pt) Pt-W alloy RPt ~ 0 (W)

FGA

0.8 0.7 0.6 0.5 0.4 0.3 0.2 Normalized capacitance

• 1.0

0.0 1.0 Voltage (V)

FGA +OGA

RPt ~ 1 (Pt) RPt ~ 0.75 RPt ~ 0.50 RPt ~ 0.25 RPt ~ 0 (W)

Changes in flatband voltage

FGA: 450ºC, 30 min OGA: 300ºC, 30 min The higher WF is, the larger the Vfb value after OGA becomes. The shift can be reversed by an additional second FGA. This observed phenomena is general and mainly depends

• n work function.

Pt W

0.5 1.0 Pt composition ratio, RPt

• 0.8
• 0.6
• 0.4
• 0.2

Flatband voltage (V)

FGA FGA+OGA FGA+OGA+FGA

~0.3 eV

HfO2/SiO2 p-Si W W-Pt Pt

HfSiON Vo Level O Vo metal

+ +

• -

SiOx IL Si sub. Ef HfSiON Vo Level Vo metal

+ +

SiOx IL

Ef

+Qeq

• Qeq

ΔV SiO2 (HfO2) +1/2Si-> Vo2+ +2e- +(HfO2)+1/2SiO2 ΔGtotal E(p+) E(p+)

(a) (b)

• -

Cdep Vo

+ +

SiOx IL Si sub.

• -
• Qeq

+Qeq small ΔVfb Flat-band Condition E(p+)

(c)

Cox

One interface affects another interface One interface affects another interface

W/HfO2/SiO2/Si Cross-section TEM (HfO2, after FGA) Pt/HfO2/SiO2/Si

5 nm 5 nm

Si W SiO2 Pt HfO2 (1) 6-nm-thick HfO2 + 1-nm-thick interfacial SiO2 layer (2) Crystallized (3) Grain size > film thickness (4) Bright portion (reaction layer?) at the metal/high-k interface.

From K.Ohmori et at from IEDM 2007

Amorphous and phase separation Amorphous and phase separation

National Institute for Material Science

Archtecture of the materials informatiocs Archtecture of the materials informatiocs

１） １）Group servors Group servors ２） ２）experiment design experiment design、 、conditions conditions、 、results results、 、 measurement data are categorized measurement data are categorized by by “ “MatLab MatLab” ” ３） ３） data sharing on website data sharing on website by XML data by XML data ４） ４）domestic and international data domestic and international data sharing on web bases sharing on web bases reference from other date reference from other date

National Institute for Material Science

Basic structure in Nano Electronics Basic structure in Nano Electronics

1) Meta/Oxide Interface 1) Meta/Oxide Interface Nano CMOS Nano CMOS Spintronics (MIM ) Spintronics (MIM ) Ohmic contact ( GaN ,ZnO) Ohmic contact ( GaN ,ZnO) 2) Oxide/ Semiconductor Interface 2) Oxide/ Semiconductor Interface Nano CMOS Nano CMOS Hetero Epitaxy on Si Hetero Epitaxy on Si 3) Metal /Oxide/ Semiconductor 3) Metal /Oxide/ Semiconductor nano scale Interface nano scale Interface Fermi level Pining Fermi level Pining Solar Cells Solar Cells

Hints from Photo catalysis Hints from Photo catalysis

Informatics Network with NIMS Informatics Network with NIMS

NIMS NIMS Tokyo Inst. of Tech Tokyo Inst. of Tech Tohoku University Tohoku University

• Univ. of Tokyo
• Univ. of Tokyo

Max Plank Institute Max Plank Institute （ （Stuttgart Stuttgart ） ）

• Univ. of North Carolina
• Univ. of North Carolina

NIST NIST University of Maryland University of Maryland

• Univ. of Washington
• Univ. of Washington

Thin film ternary phase Thin film ternary phase diagram diagram Magnetic Magnetic Material informatics Material informatics Ferroelectric Ferroelectric Thermoelectric Thermoelectric

• xides
• xides

Material Informatics and its standardisation Material Informatics and its standardisation

Reseacher Reseacher exchange exchange Professor Professor And student And student Reseacher Reseacher exchange exchange

High throughput High throughput nano nano materials exploration in materials exploration in nano nano electronics electronics １） １）Accelerating the Accelerating the nano nano materials exploration. materials exploration. ２） ２）Systematic materials data can be used Systematic materials data can be used for other research. for other research. ３） ３）Materials informatics which is shared Materials informatics which is shared with researchers or community can provide with researchers or community can provide a lot of seeds for future innovation. a lot of seeds for future innovation.