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BSIM3 MOSFET Model: BSIM3

Symbol

Summary

The Cadence® BSIM3 element is the successor of the BSIM3V322 and BSIM3V322P elements. Unlike BSIM3V322 and BSIM3V322P, which implement a single version of the BSIM3 model, version 3.22, the BSIM3 model supports versions 3.2, 3.21, 3.22, 3.23 and 3.24.

The Cadence BSIM3 model supports HSPICE Automatic Model Selection. Automatic Model Selection, also known as binning, allows for the definition of MOSFET parameter sets over specific ranges of lengths and widths. This is accomplished by implementing the BSIM3 element in terms of block (data) and instance (model) elements, BSIM3d and BSIM3m, respectively. Parameters L and W, along with a few other parameters are placed in instance element, BSIM3m, whereas the remaining BSIM3 parameters are located in the BSIM3d block element. Parameters in the block element are, in general, arrays of data. The data arrays corresponding to parameters LMIN, LMAX, WMIN and WMAX define intervals, which in turn, determine what range of L and W a specific entry in a parameter array corresponds to. As a result, setting the values of L and W in a BSIM3m element automatically selects the appropriate values from the BSIM3d block element.

Parameters

Name Description Binnable Unit Type Default
ID Element ID   Text BS1
L Gate Length   Length 0.5e-6m
W Gate Width   Length 10e-6m
*XL Length bias accounts for masking and etching effects   Length  
*XW Width bias accounts for masking and etching effects   Length  
*PD Drain diffusion perimeter   Length  
*PS Source diffusion perimeter   Length  
*AD Drain area, m^2      
*AS Source area, m^2      
*NRD No. of squares in drain area      
*NRS No. of squares in source area      
*TEMP Device temperature   Temperature 300.15K
*TNOM Extraction temperature   Temperature 300.15K
*VERSION Model version     3.22
*MOBMOD Mobility model selector     1
*CAPMOD Capacitance model selector     0
*PARAMCHK Parameter value check     0
*UCBUNITS 1: UCB units for doping & temp; 0: All MKS (legacy)     2
*NQSMOD Non Quasi Static model flag     0
*NOIMOD Noise model selector      
*NFLAG Noise flag     Noise On
*VTH0 Threshold V @ Vbs=0   Voltage  
*VFB Flat-band voltage   Voltage  
*K1 First-order body effect coef      
*K2 Second-order body effect coef      
*K3 Narrow width coef     80
*K3B Body-effect coef of K3     0
*W0 Narrow width param     2.5e-6
*NLX Lateral nonuniform doping param     1.74e-7
*VBM Minimum bulk-substrate bias for body effect calculation   Voltage -3V
*DVT0 First coef of short channel effect on Vth     2.2
*DVT1 Second coef of short channel effect on Vth     0.53
*DVT2 Body-bias coef of short channel effect on Vth     -0.032
*DVT0W 1st coef of narrow width effect on Vth (m^-1)     0
*DVT1W 2nd coef of narrow width effect on Vth (m^-1)     5.3e6
*DVT2W Body coef of narrow width effect on Vth     -0.032
*U0 Mobility (cm^2/Vsec)      
*UA First-order mobility degradation coef (m/V)     2.25e-9
*UB Second-order mobility degradation coef [(m/V)^2]     5.87e-19
*UC Body effect mobility degradation coef      
*VSAT Sat velocity (project length units/sec)     8.0e4
*A0 Bulk charge effect coef for channel length     1
*AGS Gate bias coef of ABULK (V^-1)     0
*B0 Bulk charge effect coef for channel width     0
*B1 Bulk charge effect width offset     0
*KETA Body bias coef of bulk charge effect (V^-1)     -0.047
*A1 First nonsaturation Effect Param (V^-1)     0
*A2 Second nonsaturation factor     1
*RDSW Parasitic resistance per unit width     0
*PRWB Body effect coef of RDSW     0
*PRWG Gate-bias effect coef of RDSW     0
*WR Width offset from Weff for Rds calc     1
*WINT Width offset fitting param from IV w/out bias     0
*LINT Width offset fitting prarm from IV w/out bias     0
*DWG Coef of Weff gate dependence (m/V)     0
*DWB Coef of Weff body dependence (m/V^0.5)     0
*VOFF Offset voltage in subthreshold region     -0.08
*NFACTOR Subthreshold swing factor     1
*ETA0 DIBL coef in subthreshold region     0.08
*ETAB Body coef for subthreshold DIBL effect (1/V)     -0.07
*DSUB DIBL coef exponent in subthreshold region      
*CIT Interface trap capacitance (F/m^2)     0
*CDSC DS channel coupling cap (F/m^2)     2.4e-4
*CDSCB Body bias sensitivity of CDSC (F/Vm^2)     0
*CDSCD Drain sensitivity of CDSC (F/Vm^2)     0
*PCLM Channel length modulation     1.3
*PDIBLC1 First output res DIBL param     0.39
*PDIBLC2 Second output res DIBL param     0.0086
*PDIBLCB Body effect DIBL correction param (V^-1)     0
*DROUT L dependence DIBL correction in Rout     0.56
*PSCBE1 First substrate current body effect param (V/m)     4.24e8
*PSCBE2 2nd substrate current body effect (m/V)     1e-5
*PVAG Gate dependence of Early voltage     0
*DELTA Effective Vds param     0.01
*NGATE Poly gate doping (cm^-3)     0
*ALPHA0 First param of impact ionization current (m/V)     0
*ALPHA1 Isub parameter for length scaling (1/V)     0
*BETA0 Second param of impact ionization current     30
*RSH Source-drain sheet res per sq     0
*JSW Sidewall sat current (A/m)     0
*JS S/D jcn saturation current per area (A/m^2)     1e-4
*IJTH S/D to bulk diode limiting current (Not implemented)     0.1
*XPART Charge-partitioning selector     1
*CGSO S-G overlap cap per length (F/m)      
*CGDO D-G overlap cap per length (F/m)      
*CGBO B-G overlap cap per length (F/m)      
*CJ Bottom jcn cap per area (F/m^2)     5e-4
*MJ CJ grading coef     0.5
*MJSW S&D side jcn grading coef     0.33
*CJSW S&D side jcn cap (Proj cap units/m^2)     5e-10
*CJSWG Source drain/gate sidewall jcn cap coef (Proj cap units/m)      
*MJSWG CJSWG grading coef      
*PBSW CJSW built-in voltage     1
*PB S&D Bottom jcn built-in voltage     1
*PBSWG Source drain/gate sidewall jcn cap built-in voltage      
*CGSL Light doped S-G region overlap (F/m)     0
*CGDL Light doped D-G region overlap (F/m)     0
*CKAPPA Coef for light-doped region     0.6
*CF Fringing field capacitance (F/m)      
*CLC Const term for short-channel model     0.1e-6
*CLE Exp term for short-channel model     0.6
*DLC Length offset fitting param for CV      
*DWC Width offset fitting param for CV      
*VFBCV Flat-band voltage param for CAPMOD=0 only     -1
*NOFF CV param in vgsteff for weak to strong inversion     1
*VOFFCV CV param in vgsteff for weak to strong inversion     0
*ACDE Exponential coef for charge thickness in CAPMOD=3     1
*MOIN Coef for gate-bias dependent surface potential     15
*ELM Elmore constant for the channel     5
*WL Coef of length dependence for width offset     0
*WLN Power of length dependence for width offset     1
*WW Coef of width dependence for width offset     0
*WWN Power of width dependence for width offset     1
*WWL Coef of length & width cross term for width offset     0
*LL Coef of length dependence for length offset     0
*LLN Power of length dependence for length offset     1
*LW Coef of width dependence for length offset     0
*LWN Power of width dependence for length offset     1
*LWL Coef of length and width cross term for length offset     0
*LLC Coef of length dependence foe CV length offset      
*LWC Coef of width dependence for CV length offset      
*LWLC Coef of length and width dependence for CV length offset      
*WLC Coef of length dependence for CV width offset      
*WWC Coef of width dependence for CV width offset      
*WWLC Coef of length & width dependence for CV width offset      
*UTE Mobility temp exponent     -1.5
*KT1 Temp coef for threshold voltage     -0.11
*KT1L Channel length dependence of Vth coef (Vm)     0
*KT2 Body bias coef of Vth     0.022
*UA1 Temp coef of UA     4.31e-9
*UB1 Temp coef of UB     7.61e-18
*UC1 Temp coef of UC      
*AT Temp coef of saturation velocity     3.3e4
*PRT Temp coef of RDSW     0
*NJ Emission coef of junction     1
*XTI Junction current temp exponent coef     3
*TPB Temp coef of PB     0
*TPBSW Temp coef of PBSW     0
*TPBSWG Temp coef of PBSWG     0
*TCJ Temp coef fo CJ     0
*TCJSW Temp coef of CJSW     0
*TCJSWG Temp coef of CJSWG     0
*NOIA (Noise parameter A)      
*NOIB (Noise parameter B)      
*NOIC (Noise parameter C)      
*EM (Saturation electric field parameter)     4.1e7
*AF Flicker noise exponent     1
*EF Flicker noise frequency exponent     1
*KF Flicker noise coefficient     0
*TOX Oxide thickness (m)     1.5e-8
*TOXM TOX at which params were extracted (m)      
*XJ Junction depth (m)     1.5e-7
*GAMMA1 Body-effect coef near the surface      
*GAMMA2 Body-effect coef in the bulk      
*NCH Channel doping concentration (cm^-3)     1.7e17
*NSUB Substrate doping concentration (cm^-3)      
*VBX VBS at which the depletion region equals XT      
*XT Doping depth      
*LMIN Minimum channel length for which the model is valid   Length 0m
*LMAX Maximum channel length for which the model is valid   Length 1m
*WMIN Minimum channel width for which the model is valid   Length 0m
*WMAX Maximum channel width for which the model is valid   Length 1m
*BINUNIT Units of size parameters in binning approach     1
*MULT Gate-width linear scale factor     1
*AGS Length/ width/ product Yes   0
*AT Length/ width/ product Yes   0
*KETA Length/ width/ product Yes   0
*A0 Length/ width/ product Yes   0
*B0 Length/ width/ product Yes   0
*U0 Length/ width/ product Yes   0
*UA Length/ width/ product Yes   0
*UB Length/ width/ product Yes   0
*UC Length/ width/ product Yes   0
*UC1 Length/ width/ product Yes   0
*VSAT Length/ width/ product Yes   0
*VTH0 Length/ width/ product Yes   0
*K1 Length/ width/ product Yes   0
*K2 Length/ width/ product Yes   0
*K3 Length/ width/ product Yes   0
*K3B Length/ width/ product Yes   0
*W0 Length/ width/ product Yes   0
*VOFF Length/ width/ product Yes   0
*VOFFCV Length/ width/ product Yes   0
*CIT Length/ width/ product Yes   0
*ETA0 Length/ width/ product Yes   0
*ETAB Length/ width/ product Yes   0
*PCLM Length/ width/ product Yes   0
*PDIBLC2 Length/ width/ product Yes   0
*PSCBE1 Length/ width/ product Yes   0
*KT1 Length/ width/ product Yes   0
*KT2 Length/ width/ product Yes   0
*UTE Length/ width/ product Yes   0
*UA1 Length/ width/ product Yes   0
*UB1 Length/ width/ product Yes   0
*CGSL Length/ width/ product Yes   0
*CGDL Length/ width/ product Yes   0
*RDSW Length/ width/ product Yes   0
*XJ Length/ width/ product Yes   0
*NGATE Length/ width/ product Yes   0
*NSUB Length/ width/ product Yes   0
*NCH Length/ width/ product Yes   0
*NLX Length/ width/ product Yes   0
*DVT0 Length/ width/ product Yes   0
*DVT1 Length/ width/ product Yes   0
*DVT2 Length/ width/ product Yes   0
*DVT0W Length/ width/ product Yes   0
*DVT1W Length/ width/ product Yes   0
*DVT2W Length/ width/ product Yes   0
*DSUB Length/ width/ product Yes   0
*VBM Length/ width/ product Yes   0
*B1 Length/ width/ product Yes   0
*A1 Length/ width/ product Yes   0
*A2 Length/ width/ product Yes   0
*PRWG Length/ width/ product Yes   0
*PRWB Length/ width/ product Yes   0
*WR Length/ width/ product Yes   0
*NFACTOR Length/ width/ product Yes   0
*CDSC Length/ width/ product Yes   0
*CDSCD Length/ width/ product Yes   0
*CDSCB Length/ width/ product Yes   0
*PDIBLC1 Length/ width/ product Yes   0
*PDIBLCB Length/ width/ product Yes   0
*DROUT Length/ width/ product Yes   0
*PSCBE2 Length/ width/ product Yes   0
*PVAG Length/ width/ product Yes   0
*DELTA Length/ width/ product Yes   0
*ALPHA0 Length/ width/ product Yes   0
*ALPHA1 Length/ width/ product Yes   0
*BETA0 Length/ width/ product Yes   0
*CKAPPA Length/ width/ product Yes   0
*CF Length/ width/ product Yes   0
*CLC Length/ width/ product Yes   0
*CLE Length/ width/ product Yes   0
*VFBCV Length/ width/ product Yes   0
*DWG Length/ width/ product Yes   0
*DWB Length/ width/ product Yes   0
*KT1L Length/ width/ product Yes   0
*PRT Length/ width/ product Yes   0
*GAMMA1 Length/ width/ product Yes   0
*GAMMA2 Length/ width/ product Yes   0
*VBX Length/ width/ product Yes   0
*XT Length/ width/ product Yes   0
*VFB Length/ width/ product Yes   0
*NOFF Length/ width/ product Yes   0
*ACDE Length/ width/ product Yes   0
*MOIN Length/ width/ product Yes   0
*TLEV Temperature model selector     1
*TLEVC Capacitance temperature model selector     1
*EG Energy gap at 0 K/n0.0 < EG     1.16
*GAP1 First bandgap correction factor     0
*GAP2 Second bandgap correction factor     0
*PHI Surface potential      
*PTC PHI temperature coefficient     0
*DCAP Capacitance model selector     0
*IMAX Maximum device current (for improving convergence)     1000
*ACM Area calculation method      
*CALCACM HSPICE-style area and perimeter calculations     0
*HDIF Length of heavy doped diffusion contact   Length  
*LD Lateral diffusion into channel   Length  
*LDIF Length of light diffusion region   Length  
*RDC Additional drain contact resistance      
*RSC Additional source contact resistance      
*RD Drain resistance      
*RS Source resistance      
*WMLT Channel width shrink factor      
*LMLT Channel length shrink factor      
*NLEV Noise model selector      
*GDSNOI Channel thermal noise coefficient      
*COMPAT Model compatibility selector     1
*SA0 Reference distance from OD edge to poly   Length  
*SB0 Reference distance from OD edge to poly   Length  
*SA Distance from OD edge to poly   Length  
*SB Distance from OD edge to poly   Length  
*WLOD Stress effect length parameter   Length  
*KU0 Stress effect mobility degradation/ enhancement coefficient   Length  
*STK2 VTH0 related K2 shift factor   Length  
*STETA0 VTH0 related ETA0 shift factor   Length  
*LKU0 Length dependence of KU0      
*WKU0 Width dependence of KU0      
*PKU0 Product dependence of KU0      
*TKU0 Temperature parameter for U0 stress effect      
*LLODKU0 Length parameter for U0 stress effect      
*WLODKU0 Width parameter for U0 stress effect      
*LLODVTH Length parameter for VTH stress effect      
*WLODVTH Width parameter for VTH stress effect      
*KVTH0 Threshold shift parameter for stress effect      
*LKVTH0 Length dependence of KVTH0      
*WKVTH0 Width dependence of KVTH0      
*PKVTH0 Product dependence of KVTH0      
*LODK2 Stress effect K2 shift modification factor      
*LODETA0 Stress effect ETA0 shift modification factor      
*KVSAT Stress effect saturation velocity degradation/ enhancement parameter      
*ELM Length/ width/ product Yes    
TYPE Device Type     1
*FLKMOD Spice Flicker noise model selector     0
*LDDR Length of Drain Diffusion Region   Length  
*LSDR Length of Source Diffusion Region   Length  

Operating Points

The following letter pairs have been used to identify the NL branches: ds, bs, bd, gs and gd. Here g,d,s and b correspond to the gate, drain, source and substrate terminals, respectively. These are used to identify branch related operating point information, (branch voltages, currents, etc.)

Parameter Description
vth (Voltage) Threshold voltage
vdsat (Voltage) Drain-source saturation voltage
gm (Conductance) Common-source transconductance
gds (Conductance) Common-source output conductance
gmbs (Conductance) Body-transconductance
Isub(Current) Substrate current
cgg (Capacitance) , intrinsic charge.
cgb (Capacitance) , intrinsic charge.
cgd (Capacitance) , intrinsic charge.
cgs (Capacitance) , intrinsic charge.
cbg (Capacitance) , intrinsic charge.
cbb (Capacitance) , intrinsic charge.
cbd (Capacitance) , intrinsic charge.
cbs (Capacitance) , intrinsic charge.
cdg (Capacitance) , intrinsic charge.
cdb (Capacitance) , intrinsic charge.
cdd (Capacitance) , intrinsic charge.
cds (Capacitance) , intrinsic charge.
csg (Capacitance) , intrinsic charge.
csb (Capacitance) , intrinsic charge.
csd (Capacitance) , intrinsic charge.
css (Capacitance) , intrinsic charge.
cjd (Capacitance) Drain-substrate junction capacitance
cjs (Capacitance) Source-substrate junction capacitance
pwr (Power) Dissipated power
gmoverid (None) Gm/Ids
ro (Resistance) Common-source output resistance
Cgs (Capacitance)
Cgd (Capacitance)
Cgtot (Capacitance)
Cbtot (Capacitance)
Cdtot (Capacitance)
Cstot (Capacitance)
ft (Frequency) Unity small-signal current-gain frequency

.

Implementation Details

Parameter TYPE controls whether the device is N, or P channel; which is reflected by the device symbol. BSIM3 is based on the source code released by the BSIM Research Group at UC Berkeley. However, many parameters have been added to support HSPICE and Spectre enhancements to Berkeley's original model. These extensions, among others, include a variety of ways to compute junction areas and perimeters. HSPICE Area Calculation Methods (ACM) 0, 2, 3,10, 12 and 13 are all supported.

The NFLAG and COMPAT parameters are unique to the Cadence implementation. The NFLAG parameter turns the device noise On or Off. COMPAT, the compatibility selection flag, takes three different values: HSPICE, AWR and SPECTRE. The HSPICE and Spectre values emulate HSPICE and Spectre implementations of the BSIM3 model, respectively. Parameters for which there is no default value listed in the table above, obtain their value from formulas. In many instances the default value depends on the compatibility flag setting.

Layout

This element does not have an assigned layout cell. You can assign artwork cells to any element. See “Assigning Artwork Cells to Layout of Schematic Elements” for details.

References

[1] W. Liu et al., BSIM3V3.2.2 MOSFET Model User's Manual, Dept. of Electrical Engineering and Computer Sciences, University of California, Berkeley CA 94720, USA, 1999.

[2] Y. Cheng and C. Hu, MOSFET Modeling & BSIM3 User's Guide, Norwell, MA: Kluwer, 1999.

[3] William Liu, MOSFET Models for Spice Simulation, Including BSIM3v3 and BSIM4, Wiley-IEEE, February 2001.

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