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 off-resistance. 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;
- Self-heating 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 I-V 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 self-heating 0 - no self-heating 1 - self-heating |
- |
0 |
| TSI | Silicon film thickness | m |
1e-7 |
| TBOX | Buried oxide thickness | m |
3e-7 |
| 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/m2 |
0.0 |
| ISREC | Recombination in depletion saturation current | A/m2 |
1e-5 |
| RBODY | Intrinsic body contact sheet resistance |  |
0 |
| RBSH | Extrinsic body contact sheet resistance | /m2 |
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
I-V and C-V. 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 I-V and
C-V. Body potential is properly bounded by diode and C-V formulation
- Self-heating 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 I-V 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 self-heating 0 - no self-heating 1 - self-heating |
- |
0 |
| TSI | Silicon film thickness | m |
1e-7 |
| TBOX | Buried oxide thickness | m |
3e-7 |
| 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 | W-1 |
0 |
| BGIDL | GIDL exponential coefficient | V/m |
0 |
| NGIDL | GIDL Vds enhancement coefficent | V |
1.2 |
| NTUN | reverse tunneling non-ideality factor | - |
10.0 |
| NDIODE | Diode non-ideality factor | - |
1.0 |
| ISBJT | BJT injection saturation current | A/m2 |
1e-6 |
| ISDIF | Body to source/drain injection saturation current | A/m2 |
0.0 |
| ISREC | Recombination in depletion saturation current | A/m2 |
1e-5 |
| ISTUN | Reverse tunneling saturation current | A/m2 |
0 |
| EDL | Electron diffusion length | m |
2e-6 |
| KBJT1 | Parasitic bipolar early effect coefficient | m/V |
0 |
| RBODY | Intrinsic body contact sheet resistance | /m2 |
0 |
| RBSH | Extrinsic body contact sheet resistance | /m2 |
0 |
| CGE0 | Gate substrate overlap capacitance per unit channel length | F/m |
0.0 |
| TT | Diffusion capacitance transit time coefficient | s |
1e-12 |
| 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 C-V and
I-V. 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 (high-level 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
body-contact and isolation structures
- An external body node (the 6th node) and other
improvements are introduced to facilitate the modeling of distributed
body-resistance
- Self-heating: 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 self-heating |
- |
0 |
| TSI | Silicon film thickness | m |
1e-7 |
| TBOX | Buried oxide thickness | m |
3e-7 |
| 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 cur-rent | 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 cur-rent | V/m |
1e7 |
| SII0 | First vgs dependent parameter for impact ionization cur-rent | 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 cur-rent | 1/V |
0 |
| SIID | vds dependent parameter of drain saturation voltage for impact ionization current | 1/V |
0 |
| AGIDL | DIDL constant | W-1 | 0 |
| BGIDL | GIDL exponential coefficient | V/m | 0 |
| NGIDL | GIDL Vds enhancement coefficent | V | 1.2 |
| NTUN | reverse tunneling non-ideality factor | - | 10.0 |
| NDIODE | Diode non-ideality factor | - | 1.0 |
| NRECF0 | Recombination non-ideality factor at forward bias | - | 2.0 |
| NRECR0 | Recombination non-ideality factor at reversed bias | - | 10.0 |
| ISBJT | BJT injection saturation current | A/m2 | 1e-6 |
| ISDIF | Body to source/drain injection saturation current | A/m2 | 0 |
| ISREC | Recombination in depletion saturation current | A/m2 | 1e-5 |
| ISTUN | Reverse tunneling saturation current | A/m2 | 0 |
| LN | Electron/hole diffusion length | m | 2e-6 |
| 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 e-6 |
| 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/m2 | 0 |
| RBSH | Extrinsic body contact sheet resistance W/m2 0 | W/m2 | 0 |
| TT | Diffusion capacitance transit time coefficient | s | 1e-12 |
| 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 C-V | 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 gate-bias dependent surface potential | V0.5 | 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 Id-Vds curves with FD and DD models
(default model card from Berkeley)
Figure 2 : Example of Id-Vds curves with PD
model (default model card from Berkeley)
Figure 3. Self-heating 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