Download - MURI Plans
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MURI PlansMURI Plans
S. E. Thompson March 27, 2005
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TI Fellows Forum
OUTLINEOUTLINE
• SRC and AMD, AMAT, IBM, Intel, TSMC, TI, UMC funded device modeling/characterization work
• Plans: Single event transient– Start with SRC strained Si modeling/calibration– SET on State-of-the-art uniaxial strained Si (90-45nm)– SET on Future strained devices
• Strained Ge transistor• Strained Si and Ge on (110) wafers
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1-2.5GPa stress film
Post salicide
Si1-xGex
45nm
Si1-xGex
Removable film pre-anneal
Nitride
Gate Gatestress stressa-Si a-Si
Many Ways to Do StrainMany Ways to Do Strain
Even more on high stress layers
Intel 2004 EDL
TI 2004 VLSI
AMAT 2004 IEDM
IBM 2005 VLSI
TSMC/Freescalse 2005
Samsung 2005 VLSI
Hoyt
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Strain Being Adopted by AllStrain Being Adopted by All
Si1-xGex
p-type MOSFET
Si1-xGex
Strained Si
45 nm
stress stress
NMOS PMOS
Gate
STI
Tensile Nitride Compressive Nitride
Gate
FujitsuSource: Ti
Source Chipworks: 90 nm Intel,IBM,AMD,TI,Fujitsu
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Why Strain: Very Impressive Performance Why Strain: Very Impressive Performance
2004 IEDM Intel
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Significantly Alters Band Structure/Transport
E
K <110>
HeavyHole
Light Hole
UniaxialLongitudinal Compression
Biaxial Tension
Uniaxial Longitudinal Tension
Valance Band warping, changes m*,
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TI Fellows Forum (μm)
(μm
)
45 nm
140
nm
120
nm
30 nm
Si0.83Ge0.17Si0.83Ge0.17
STI STI
-536
-83403
95
31
Stress ContoursStress Contours
Source FLOOPs
MPa
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Device Level Calibration: SRC/Intel FundedDevice Level Calibration: SRC/Intel Funded
• Industrial samples– 30 nm to 1um Si trasistors from 3 companies– Unstressed, uniaxial and biaxial stressed wafer– Bulk and SOI– Fully depleted SOI /Metal Gate– High k/metal gate and sub-micron Ge channel devices
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Four-Point Bending Set-UpFour-Point Bending Set-Up
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-50-40-30
-20-10
0
102030
4050
-500 -300300 500
Stress / MPa
Mob
ility
Enh
ance
men
t (
%)
Uniaxial Longitudinal
SiGe S/D [4]
Uniaxial Transverse
Biaxial
Biaxial Rim
DataModel
Strain Enhanced Mobility: Strain Enhanced Mobility: Model / MeasuredModel / Measured
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6 Band K P Including Confinement6 Band K P Including Confinement
( ) ( )[ ] ( ) ( ) ( )zkEzzVzkHkkvv
vvψψ =+,
( )
⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢
⎣
⎡
=
⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢
⎣
⎡
⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢
⎣
⎡
+
−
+
−
++−
+−
+−−
.
.
.
.
.......
.ˆˆˆ00.
.0ˆˆˆ0.
.00ˆˆˆ.
.......
1
1
1
1
1
1
i
i
i
i
i
i
i
i
i
KE
HHH
HHH
HHH
ψ
ψ
ψ
ψ
ψ
ψv
Schrodinger’s Equation and Poisson’s Equation solved self-consistently using the Finite-Difference Method.
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Si and Ge Band StructureSi and Ge Band Structure
GeSi
No Stress
Biaxial Stress
Longitudinal compression
HH LH HH LH
Top Bottom Top Bottom
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In and Out-of-Plane Masses (Ge)In and Out-of-Plane Masses (Ge)
m||
m|
m||
m|
kzkz
kyky
Uniaxial StressBiaxial Stress
kx kx
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Si and Ge Band Structure on (100) and (110)Si and Ge Band Structure on (100) and (110)
SiGe
Longitudinal compression
Top Bottom Top Bottom
(100)
(110) hybrid
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( )
( )
∫∂∂
=π
φ
ν
ν
φφπ
2
0
,
,
2
1)(
EKKE
EKdEg
Si is confined in kz direction. 2-dimensional density of state is given by:
And total charge density over all possible bands:
( )( )∑∫
∞
⎟⎟⎠
⎞⎜⎜⎝
⎛ −++=
ν ν0 0
exp1Tk
EEE
EgdEp
B
F
Full Transport Model: Calculation of Full Transport Model: Calculation of Density of StatesDensity of States
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Density of States MassDensity of States Mass
0.1 1 10 0
0.5
1
1.5
2
2.5
3
Stress / GPa
Eff
ectiv
e M
ass
m*/
m0
Longitudinal compressive
Biaxial tensile
Production level stress
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Summary / Next StepsSummary / Next Steps
• First-principles quantum mechanical methods for strained Si band structure
• Spatially dependent strain-induced band structure
• Model charge transport and collection due to single event in FLOOPS/FLOODS– Start with existing MURI developed models– Add strain for Si and Ge transistors
