BSIM3SOI Version 2.1 (FD, DD and PD)
Models Released in SmartSpice
Introduction
The Berkeley BSIM3SOI version 2.1 models, released in September 1999, have been implemented in SmartSpice. The three new models are selected according to LEVEL selector.
 LEVEL = 26 selects the BSIM3SOI2FD (Fully depleted) model
 LEVEL = 27 selects the BSIM3SOI2DD (Dynamic depletion) model
 LEVEL = 29 selects the BSIM3SOI2PD (Partially depleted) model
The SmartSpice implementation of the three models is close but not identical to the UC Berkeley releases. The SmartSpice implementation provides a number of improvements and additional parameters currently unsupported in Berkeley's BSIM3SOIv2 models.
In the SmartSpice implementation of the BSIM3SOIv2 models, enhanced convergence is obtained by properly handling the GMIN and DCGMIN control options during transient and DC analysis.
The GMIN option connects a conductance in parallel with the bulk diodes. This conductance is very useful when the diode model has a very high offresistance. The conductance DCGMIN is connected between drain and source.
The present section provides all the information needed to understand and use the three models.
BSIM3SOI FD (Fully Depleted) version 2.1 (Model LEVEL = 26)
Major Features
BSIM3SOI FD v2.1 is a suite of BSIM3SOI FD v2.0 released in
February 1999. The version 2.0 is a derivative of BSIM3SOI v1.3
(level=25 in SmartSpice). BSIM3SOIFDv2.0 has improved
simulation efficiency and noise modeling. The basic IV for this
model is modified from BSIM3v3.1 equation set. The major features
are summarized as follows [1]:
 Supports external body bias and backgate bias
: a total of 5 external nodes;
 Selfheating implementation improved over the
alpha version of Berkeley (LEVEL 23 in SmartSpice);
 New depletion charge model (EBCI) introduced
for better accuracy in capacitive coupling prediction. An improved
BSIM3v3 based model is added as well;
 Single IV expression as in BSIM3v3.1 to guarantee continuities of Ids, Gm, and Gds and their derivatives for all bias conditions.
New version BSIM3SOI FDv2.1 includes the binning feature to enhance the model flexibility and fixes some bugs found in the previous version 2.0.
Model Parameters
The additional parameters to BSIM3v3 listed in Table 1 correspond
to the BSIM3SOI FD Version 2.1 model.
Parameter  Description  Units  Default 
SHMOD  Flag for selfheating 0  no selfheating 1  selfheating 
 
0 
TSI  Silicon film thickness  m 
1e7 
TBOX  Buried oxide thickness  m 
3e7 
VBSA  Transition body voltage offset  V 
0 
DELP  Constant for limiting Vbseff to Phis  V 
0.02 
KB1  Coefficient of Vbs0 dependency on Ves   
1 
KB3  Coefficient of Vbs0 dependency on Vgs at subthreshold region   
1 
DVBD0  First coefficient of Vbs0 dependency on Leff  V 
0 
DVBD1  Second coefficient of Vbs0 dependency on Leff  V 
0 
MXC  Fitting parameter for Abeff calculation   
0.9 
ADICE0  DICE bulk charge factor   
1 
ISDIF  Body to source/drain injection saturation current  A/m^{2} 
0.0 
ISREC  Recombination in depletion saturation current  A/m^{2} 
1e5 
RBODY  Intrinsic body contact sheet resistance  0 

RBSH  Extrinsic body contact sheet resistance  /m^{2} 
0 
CGE0  Gate substrate overlap capacitance per unit channel length  F/m 
0.0 
VSDFB  Source/drain bottom diffusion capacitance flatband voltage  V 
calculated 
VSDTH  Source/drain bottom diffusion capacitance threshold voltage  V 
calculated 
CSDMIN  Source/drain bottom diffusion minimum capacitance  F 
calculated 
ASD  Source/drain bottom diffusion minimum parameter   
0.3 
CSDESW  Source/drain sidewall fringing capacitance per unit length  F/m 
0 
CTH0  Normalized thermal capacity  m.°C/(W*s) 
0 
RTH0  RTH0 Normalized thermal resistance  m.°C/W 
0 
correspond to the BSIM3SOI FD Version 2.1 model.
Silvaco Improvements
Options
The options VZERO and EXPERT are supported in the
SmartSpice BSIM3SOI FD v2.1 model. The option VZERO=2
allows faster runtime when large circuits are used.
The EXPERT option can be specified to detect possible problems in models, before and during simulation, such as:
 negative conductances GM, GDS and GMBS,
 negative gate capacitances.
New Model Parameters
New model parameters are listed in the following table :
Parameter  Description  Units  Default 
VERSION  Version selector    2.1 
LMIN  Limit for binning  m  0.0 
LMAX  Limit for binning  m  1.0 
WMIN  Limit for binning  m  0.0 
WMAX  Limit for binning  m  1.0 
The VERSION model parameter is used to switch between the current
versions 2.0 and 2.1. The four others new model parameters are used
for binning to select a model. For the binning, Silvaco has also
added new binned model parameters that are displayed in Table 2.
AT  GAMMA1  GAMMA2  VBM  VBX  XT  KT1 
KT1L  KT2  UA1  UB1  UC1  UTE  RTH0 
PRT  CGDL  CGSL  CKAPPA  CF  CLC  CLE 
XJ  RBODY  CSDMIN  CTH0  ASD  CSDESW 
Table 2. Silvaco's new binned
model parameters.
BSIM3SOI DD (Dynamic Depletion) Version 2.1 Model (LEVEL=27)
Major Features
BSIM3SOI DD v2.1 is a suite of BSIM3SOI DD v2.0 released in February
1999. The version 2.0 is a derivative of BSIM3SOI v1.3 (level=25
in SmartSpice). BSIM3SOI DD v2.0 has improved simulation
efficiency and noise modeling. The BSIM3SOI DDv2.0 model can be
used for both Partially Depleted (PD) and Fully Depleted (FD). The
basic IV for this model is modified from BSIM3v3.1 equation set.
The major features are summarized as follows [2]:
 Dynamic depletion approach is applied on both
IV and CV. Charge and drain current are scalable with Tbox and
Tsi continuously
 Supports external body bias and backgate bias
: a total of 5 external nodes
 Real floating body simulation in both IV and
CV. Body potential is properly bounded by diode and CV formulation
 Selfheating implementation improved over the
alpha version of Berkeley (LEVEL 23 in SmartSpice)
 An improved impact ionization current model
 Various diode leakage components and parasitic
bipolar current included
 New depletion charge model (EBCI) introduced
for better accuracy in capacitive coupling prediction. An improved
BSIM3v3 based model is added as well
 Dynamic depletion can suit different requirements
for SOI technologies
 Single IV expression as in BSIM3v3.1 to guarantee continuities of Ids, Gm, and Gds and their derivatives for all bias conditions
New version BSIM3SOI DDv2.1 includes the binning feature to enhance
the model flexibility and fixes some bugs found in the previous
version 2.0.
Model Parameters
The additional parameters to BSIM3v3 listed below in Table 3 correspond
to the BSIM3SOI DD Version 2.1 model.
Parameter  Description  Units  Default 
SHMOD  Flag for selfheating 0  no selfheating 1  selfheating 
 
0 
TSI  Silicon film thickness  m 
1e7 
TBOX  Buried oxide thickness  m 
3e7 
VBSA  Transition body voltage offset  V 
0 
DELP  Constant for limiting Vbseff to Phis  V 
0.02 
KB1  Coefficient of Vbs0 dependency on Ves   
1 
KB3  Coefficient of Vbs0 dependency on Vgs at subthreshold region   
1 
DVBD0  First coefficient of Vbs0 dependency on Leff  V 
0 
DVBD1  Second coefficient of Vbs0 dependency on Leff  V 
0 
ABP  Coefficient of Abeff dependency on Vgst   
1 
MXC  Fitting parameter for Abeff calculation   
0.9 
ADICE0  DICE bulk charge factor   
1 
ALPHA1  The second parameter of impact ionization current  m/V 
1.0 
AII  First Vds dependence Ecrit parameter   
0 
BII  Second Vds dependence Ecrit parameter  m 
0 
CII  Vgsteff dependence Ecrit parameter  1/m 
0 
DII  Vbseff dependence Ecrit parameter  1/m 
1.0 
AGIDL  GIDL constant  W1 
0 
BGIDL  GIDL exponential coefficient  V/m 
0 
NGIDL  GIDL Vds enhancement coefficent  V 
1.2 
NTUN  reverse tunneling nonideality factor   
10.0 
NDIODE  Diode nonideality factor   
1.0 
ISBJT  BJT injection saturation current  A/m^{2} 
1e6 
ISDIF  Body to source/drain injection saturation current  A/m^{2} 
0.0 
ISREC  Recombination in depletion saturation current  A/m^{2} 
1e5 
ISTUN  Reverse tunneling saturation current  A/m^{2} 
0 
EDL  Electron diffusion length  m 
2e6 
KBJT1  Parasitic bipolar early effect coefficient  m/V 
0 
RBODY  Intrinsic body contact sheet resistance  /m^{2} 
0 
RBSH  Extrinsic body contact sheet resistance  /m^{2} 
0 
CGE0  Gate substrate overlap capacitance per unit channel length  F/m 
0.0 
TT  Diffusion capacitance transit time coefficient  s 
1e12 
VSDFB  Source/drain bottom diffusion capacitance flatband voltage  V 
calculated 
VSDTH  Source/drain bottom diffusion capacitance threshold voltage  V 
calculated 
CSDMIN  Source/drain bottom diffusion minimum capacitance  F 
calculated 
ASD  Source/drain bottom diffusion minimum parameter   
0.3 
CSDESW  Source/drain sidewall fringing capacitance per unit length  F/m 
0 
CTH0  Normalized thermal capacity  m.°C / (W*sec) 
0 
RTH0  Normalized thermal resistance  m.°C/W 
0 
XBJT  Power dependence of jbjt on temperature   
2 
XDIF  Power dependence of jdif on temperature   
2 
XREC  Power dependence of jrec on temperature   
20 
XTUN  Power dependence of jtun on temperature   
0 
NOIF  Floating body excess noise ideality factor   
1.0 
Table 3. The additional parameters to BSIM3v3 correspond
to the BSIM3SOI DD Version 2.1 model.
Silvaco Improvements
Options
The options VZERO and EXPERT are supported in the SmartSpice BSIM3SOI DD v2.1 model.
The option VZERO=2 allows faster runtime when large circuits are used.
The EXPERT option can be specified to detect possible problems in models, before and during simulation, such as:
 negative conductances GM, GDS and GMBS
 negative gate capacitances
New Model Parameters
New model parameters are listed in the following table :
Parameter  Description  Units  Default 
VERSION  Version selector    2.1 
SMART  Improvement selector    1 
LMIN  Limit for binning  m  0.0 
LMAX  Limit for binning  m  1.0 
WMIN  Limit for binning  m  0.0 
WMAX  Limit for binning  m  1.0 
The VERSION model parameter is used to switch between the current version 2.0 and 2.1. The four new model parameters (LMIN, LMAX, WMIN and WMAX) are used for binning to select a model. For the binning, Silvaco has also added the following new binned model parameters shown in Table 4.
The SMART model parameter Silvaco improvements which are not compatible with original Berkeley model allows to switch on . SMART model parameter has been created as follows :
 if SMART = 0: the original Berkeley model is used with its different versions
 if SMART > 0: the Berkeley model is used with the following improvements:
 problem with RBODY model parameter has been fixed;
 some derivatives related to body tied have been corrected;
 the limitation of vb has been modified.
BSIM3SOI PD (Partially depleted) version
AT  GAMMA1  GAMMA2  VBM  VBX  XT  KT1 
KT1L  KT2  UA1  UB1  UC1  UTE  RTH0 
PRT  CGDL  CGSL  CKAPPA  CF  CLC  CLE 
XJ  RBODY  CSDMIN  CTH0  ASD  CSDESW  CJSWG 
PBSWG  MJSWG  TT  XBJT  XDIF  XREC  XTUN 
Table 4. Silvaco's new binned model parameters.
2.1 Model (LEVEL = 29)
Major Features
BSIM3SOI PD v2.1 is a suite of BSIM3SOI PD v2.01 released in April
1999. The version 2.01 is a derivative of BSIM3SOI v1.3 (level=25
in Smartspice). Many enhanced features are included in BSIM3SOI
PD v2.0.1. BSIM3SOI PD v2.0.1 has the following new features relative
to BSIM3SOIv1.3 [3]:
 Real floating body simulation in both CV and
IV. The body potential is determined by the balance of all the
body current components
 Enhancements in the threshold voltage and bulk
charge formulation of the high positive body bias regime
 An improved parasitic bipolar current model.
This includes enhancements in the various diode leakage components,
second order effects (highlevel injection & early effect), diffusion
charge equation and temperature dependence of the diode junction
capacitance
 An improved impact ionization current model.
The contribution from BJT current is also modeled by the parameter
FBJTII
 Instance parameters (PDBCP, PSBCP, AGBCP, AEBCP,
NBC) are provided to model the parasitics of devices with various
bodycontact and isolation structures
 An external body node (the 6th node) and other
improvements are introduced to facilitate the modeling of distributed
bodyresistance
 Selfheating: an external temperature node (the
7th node) is supported to facilitate the simulation of thermal
coupling among neighboring devices
 A unique SOI low frequency noise model, including
a new excess noise resulting from the floating body effect
 Width dependence of the body effect is modeled
by parameters (K1, K1W1, K1W2)
 Improved history dependence of the body charges
with two new parameters (FBODY, DLCB)
 An instance parameter vbsusr is provided for users to set the transient initial condition of the body potential
Model Parameters
The additional parameters to BSIM3v3 listed in Table 5 correspond to the BSIM3SOI PD Version 2.1 model.
Parameter  Description  Units  Default 
SHMOD  Flag for selfheating 
 
0 
TSI  Silicon film thickness  m 
1e7 
TBOX  Buried oxide thickness  m 
3e7 
KIW1  First body effect with dependent parameter  m 
0 
KIW2  Second body effect with dependent parameter  m 
0 
KB1  Coefficient of Vbs0 dependency on Ves   
1 
KETAS  Surface potential adjustment for bulk charge effect  V 
0 
DWBC  Width offset for body contact isolation edge  m 
0.0 
FBJTII  Fraction of bipolar current affecting the impact ionization  m/V 
0.0 
BETA0  First Vds dependence parameter of impact ionization current  1/V 
0 
BETA1  Second Vds dependence parameter of impact ionization current  1/V 
0 
BETA2  Third Vds dependence parameter of impact ionization current  V 
0.1 
VDSATII0  Nominal drain saturation voltage at threshold for impact ionization current  V 
0.9 
TII  Temperature dependent parameter for impact ionization current   
0 
LII  Channel length dependent parameter at threshold for impact ionization current   
0 
ESATII  Saturation channel electric field for impact ionization current  V/m 
1e7 
SII0  First vgs dependent parameter for impact ionization current  1/V 
0.5 
SII1  Second vgs dependent parameter for impact ionization current  1/V 
0.1 
SII2  Third vgs dependent parameter for impact ionization current  1/V 
0 
SIID  vds dependent parameter of drain saturation voltage for impact ionization current  1/V 
0 
AGIDL  DIDL constant  W1  0 
BGIDL  GIDL exponential coefficient  V/m  0 
NGIDL  GIDL Vds enhancement coefficent  V  1.2 
NTUN  reverse tunneling nonideality factor    10.0 
NDIODE  Diode nonideality factor    1.0 
NRECF0  Recombination nonideality factor at forward bias    2.0 
NRECR0  Recombination nonideality factor at reversed bias    10.0 
ISBJT  BJT injection saturation current  A/m^{2}  1e6 
ISDIF  Body to source/drain injection saturation current  A/m^{2}  0 
ISREC  Recombination in depletion saturation current  A/m^{2}  1e5 
ISTUN  Reverse tunneling saturation current  A/m^{2}  0 
LN  Electron/hole diffusion length  m  2e6 
VREC0  Voltage dependent parameter for recombination current  V  0 
VTUN0  Voltage dependent parameter for tunneling current  V  0 
NBJT  Power coefficient of channel length dependency for bipolar current    1 
LBJT0  Reference channel length for bipolar current  m  0.2 e6 
VABJT  Early voltage for bipolar current  V  10 
AELY  Channel length dependency of early voltage bipolar current  V/m  0 
AHLI  High level injection parameter for bipolar current    0 
RBODY  Intrinsic body contact sheet resistance  W/m^{2}  0 
RBSH  Extrinsic body contact sheet resistance W/m2 0  W/m^{2}  0 
TT  Diffusion capacitance transit time coefficient  s  1e12 
NDIF  Power coefficient of channel length dependency for diffusion capacitance    1 
LDIF0  Channel length dependency coefficient of diffusion capacitance    1 
VSDFB  Source/drain bottom diffusion capacitance flatband voltage  V  calculated 
VSDTH  Source/drain bottom diffusion capacitance threshold voltage  V  calculated 
CSDMIN  Source/drain bottom diffusion minimum capacitance    calculated 
ASD  Source/drain bottom diffusion minimum parameter    0.3 
CSDESW  Source/drain sidewall fringing capacitance per unit length  F/m  0 
DLCB  Length offset fitting parameter for body charge  m  0.0 
DLBG  Length offset fitting parameter for backgate charge  m  0.0 
DELVT  Threshold voltage adjust for CV  V  0.0 
FBODY  Scaling factor for body charge    1.0 
ACDE  Exponetial coefficient for charge thickness in CAPMOD=3 for accumulation and depletion regions  m/V  1.0 
MOIN  Coefficient for the gatebias dependent surface potential  V^{0.5}  15.0 
TCJSWG  Temperature coefficient of CJSWG 1/K 0  1/K  0 
TPBSWG  Temperature coefficient of PBSWG  V/K  0 
CTH0  Normalized thermal capacity  m.°C / (W*sec)  0 
RTH0  Normalized thermal resistance  m.°C/W  0 
NTRECF  Temperature coefficient for NRECF    0 
NTRECR  Temperature coefficient for NRECR    0 
XBJT  Power dependence of jbjt on temperature    1 
XDIF  Power dependence of jdif on temperature    XBJT 
XREC  Power dependence of jrec on temperature    1 
XTUN  Power dependence of jtun on temperature    0 
Table 5. The additional parameters to BSIM3v3 correspond
to the BSIM3SOI PD Version 2.1 model.
Silvaco Improvements
Options
The options VZERO and EXPERT are supported in the SmartSpice
BSIM3SOI PD v2.1 model.
The option VZERO=2 allows faster runtime when large circuits are
used.
The EXPERT option can be specified to detect possible problems in
models, before and during simulation, such as:
 negative conductances GM, GDS and GMBS
 negative gate capacitances.
New model parameters
New model parameters are listed in the following table:
Parameter  Description  Units  Default 
VERSION  Version selector    2.1 
SMART  Improvement selector    1 
LMIN  Limit for binning  m  0.0 
LMAX  Limit for binning  m  1.0 
WMIN  Limit for binning  m  0.0 
WMAX  Limit for binning  m  1.0 
The VERSION model parameter is used to switch between the current versions 2.0.1 and 2.1. The four new model parameters (LMIN, LMAX, WMIN and WMAX) are used for binning to select a model. For the binning, Silvaco has also added the following new binned model parameters shown in Table 6.
AT  GAMMA1  GAMMA2  VBM  VBX  XT  KT1 
KT1L  KT2  UA1  UB1  UC1  UTE  RTH0 
PRT  CGDL  CGSL  CKAPPA  CF  CLC  CLE 
XJ  RBODY  CSDMIN  CTH0  ASD  CSDESW  CJSWG 
PBSWG  MJSWG  TT  XBJT  XDIF  XREC  XTUN 
LN  NDIF  LDIF0  TCJSWG  TPBSWG  NTRECF  NTRECR 
The SMART model parameter allows to switch on Silvaco improvements
which are not compatible with original Berkeley model. The SMART
model parameter has been created as follows :
 if SMART = 0: the original Berkeley model is
used with its different versions
 if SMART > 0: the Berkeley model is used with the following improvements:
 incorrect implementation of model parameter AHLI has been fixed;
 the limitation of vb has been modified.
Figures 1, 2, 3 and 4 illustrate different models.
Figure 1 : Example of IdVds curves with FD and DD models
(default model card from Berkeley)
Figure 2 : Example of IdVds curves with PD
model (default model card from Berkeley)
Figure 3. Selfheating effect with PD model
(default model card from Berkeley)
Figure 4. Example of a ring oscillator with PD
model (default model card from Berkeley)
References
 BSIM3SOIFDv2.1 User's Manual, 1999, Department of EECS, University of California, Berkeley
 BSIM3SOIDDv2.1 User's Manual, 1999, Department of EECS, University of California, Berkeley
 BSIM3SOIPDv2.1 User's Manual, 1999, Department of EECS, University of California, Berkeley