murty, johnson, harame
TRANSCRIPT
Murty, Johnson, Harame BCTM 2001
RF BiCMOS Device Modeling
Extraction of HiCUM Model Parameters for SiGe Bipolar Transistors
M. Ramana Murty, J.Johnson and D. Harame9/27/01
Murty, Johnson, Harame BCTM 2001
RF BiCMOS Device Modeling
Outline
• Extraction of Resistances• Base Resistances: CBEB Test Structure• Emitter Resistance: Open-Collector Method• Collector resistance: Test-Structure
• Extraction of Junction Capacitances• Cold S-Parameters (CBEBC Transistors)+ Test-Structures
• Extraction of Avalanche Parameters• Ib vs Vbc Characteristics (CBEBC Transistors)
• Extraction of Current Parameters• Gummel and Transfer Current Characteristics (CBEBC Transistors)
• Extraction of Transit Time parameters• Active S-Parameters (CBEBC Transistors)
Murty, Johnson, Harame BCTM 2001
RF BiCMOS Device Modeling
Base-link Resistance be0/∆l
R (O )
Extrinsic Base Resistance
Test-Structure to Measure Base Resistances
• CBEB Configuration• l = 4.5 and 10 um• b = 0 to 0.8 (5-sizes)
B1
B2
C
E
Murty, Johnson, Harame BCTM 2001
RF BiCMOS Device Modeling
Base Pinch Resistance and Zero Bias Hole Charge
rsBi (O/Sq )
Vbe(V)
chargesjunction internal theare Q and Q
and 0
here
, 0
11
jcijEi
∫=+==
=−
bejjcijEi dVCQQQjrsBirsBir
pQjQ
r
(1/r-1)
Qj
Vce= 0 and 0.5 V
Murty, Johnson, Harame BCTM 2001
RF BiCMOS Device Modeling
Emitter Resistance: Open Collector method
Set Ic=0, Vary Vbe, Measure Vce, Ib. Plot Vce vs Ie and fit to:
baseinternal under the collector in mobilities
,1
2
1ln
=
+=
++=
µµµµ
µ
pc
nc
T
os
EEECE
Vf
IIfIrV VCE (V)
IE (A)
1/AE0
rE(Ω) Slope=ρKE
Offset ?
Murty, Johnson, Harame BCTM 2001
RF BiCMOS Device Modeling
Junction Capacitances – Cold S-parameter Method
Cold => Vbe= -0.5 to +0.5 V, Vbc=0 and Vbe=0, Vce= -0.5 to +3.5 V
+=
+
−=
−=
+=
22121
22121.2
12
)12(2
)12()11(
YYrealRsub
YYimagf
Ccs
fYimagCbc
fYimagYimagCbe
π
π
πB
E
C
Sub
Cbc
Cbe
Ccs
Rsub
Eq.ckt under Cold operation
Murty, Johnson, Harame BCTM 2001
RF BiCMOS Device Modeling
Cold S-par Cbcmeas.
Cbc=Cbcmeas-Ccox
Polyfit Cbc vs. size
Intercept= area partOf (Cbci+Cextbase)
Slope =peri part of Cjcb
Subtract Cex
Fit to C-V equ,=>c’jcb,m,vbi
Fit to C-V equ,=>cjci,m,vbi
Cextbase fromCapmons(CAC2XB)Cjcb,m,vbi
Ccox (=oxideoverSTI) :Capmons(CAC2XBMS)
Extraction Flow of the Components of Cbc
Murty, Johnson, Harame BCTM 2001
RF BiCMOS Device Modeling
• CBEBC Structures: b=0.16, 0.32, 0.48, 0.64, 0.96 and l=8.4 um• Corrected for (a) Emitter Spacer, (b) extrinsic base and (c) oxide capacitance.• Fit to classical C-V relationship
CperiVs VoltageCarea Vs Voltage
Separation of Cbc into its Components
Murty, Johnson, Harame BCTM 2001
RF BiCMOS Device Modeling
Base-Collector Weak Avalanche Model
2/ and 2 , )()0( where
)(exp)(
''''
''''
EnAVLn
nAVLCBbCBbAVL
CBDCijCi
AVLCBDCiAVLTAVL
AbqbafVIVII
VVCqVVfII
ε==−==
−−−=
I b(nA
)
I avl(n
A)
Vbc (V) -Vbc (V)
• Ib and Ic measured at a low Vbe where self-heating effects are negligible
5 device sizes
Murty, Johnson, Harame BCTM 2001
RF BiCMOS Device Modeling
Separation of Ibe into Area and Perimeter Components
• Ibe has no perimeter component as implied by the Ibe/A Vs P/A plot
I beA (A
)
Murty, Johnson, Harame BCTM 2001
RF BiCMOS Device Modeling
Separation of Ic into Area and Perimeter Components
Murty, Johnson, Harame BCTM 2001
RF BiCMOS Device Modeling
Is=9.12e-19Qp0= 3.18e-14mcF=1.035
T
BE
BEjEip
psc V
VVQQ
QII +
++=
)(log)log()log(
0
0
Bias Dependent Early Effect
Ic(a
rea)
(Am
p)
Vbe (V)
Murty, Johnson, Harame BCTM 2001
RF BiCMOS Device Modeling
Transit Time- Low Ic Region
( ) cppfciifEEfEf
CBjci
jciBfvlhf
bcB
ECxfT
IIbIcbbQVC
Cc
cc
gmCCrrr
f
..)(.)(
)( ,11)1(
.2
1
0000000
''
0000
0
τττ
ττττ
βτ
π
+==
=
−+−∆+=
Σ+
+++=
Qf0(area)= 5.7x10-17 Cτf0i/τf0p= 1.857
1/2π
f T (p
s)
16
10
21x103 4x103 7x103
1/Ic(low) (A-1)
Murty, Johnson, Harame BCTM 2001
RF BiCMOS Device Modeling
1 ; 11
; .
.21.2
22
c
ck
hc
hc
hcc
ckhCs i
Iiaaii
waii
Iwfh −=++++
=
++=∆ ττ
Transit Time- High Ic Region and Critical Current Parameters
0.48x8.4 µm
Ick referred ∆τf
Murty, Johnson, Harame BCTM 2001
RF BiCMOS Device Modeling
PTceff
ceff
ceffck VVvxxx
Vvrci
vI ).( ;
2101
lim1
10
lim
32
2−=
+++
+
=−
Ick vs VC’E’ for w = 0.16, 0.32, 0.48, 0.64, 0.96 um
Transit Time-Determination of the Ick Parameters
Murty, Johnson, Harame BCTM 2001
RF BiCMOS Device Modeling
Conclusions
• Several of the HiCUM Model Parameters are Extracted and their Physical Meaningfulness Verified.
• Extraction of High-current parameters, Non-quasi-static effect parameters etc. is underway
3.
Murty, Johnson, Harame BCTM 2001
RF BiCMOS Device Modeling
A Screen-shot of the Structure Data Required in Tradica
SEM+SIMS
Murty, Johnson, Harame BCTM 2001
RF BiCMOS Device Modeling
A Screen-shot of the Model Parameter Data(1) Required in Tradica
Murty, Johnson, Harame BCTM 2001
RF BiCMOS Device Modeling
A Screen-shot of the Model Parameter Data(2) Required in Tradica
Murty, Johnson, Harame BCTM 2001
RF BiCMOS Device Modeling
Murty, Johnson, Harame BCTM 2001
RF BiCMOS Device Modeling