BSIM-SOI 4.6.0 Technical Manual
BSIM-SOI 4.6.0 Technical Manual
0 MOSFET MODEL
                           Users’ Manual
                                 BSIM GROUP
                                    May 2017
                                  Copyright  2017
                      The Regents of the University of California
                                 All Rights Reserved
 The development of BSIMSOIv4.6.0 benefited from the input of many BSIMSOI users,
 especially the Compact Model Coalition (CMC) member companies. The developers would
 like to thank Joe Saurabh Sirohi and Richard Williams at IBM, Joddy Wang, Jane Xi, and
 Weidong Liu at Synopsys, Geoffrey Coram at ADI, Jushan Xie and Yunpeng Pei at
 Cadence, Jung-Suk Goo at GLOBALFOUNDRIES, Thomas Miller and Samuel Mertens
 at Agilent Technologies, Ahmed Ramadan at Mentor Graphics and James Ma at ProPlus
 Design Solutions for their valuable assistance in identifying the desirable modifications
 and testing of the new model.
6.2. Verification 41
B.3. DC Parameters 71
References 123
Chapter 1: Introduction
      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 [3].
      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.
      The new charge-thickness capacitance model introduced in BSIM3v3.2 [4], capMod=3,
       is included.
8. Improved model accuracy in moderate inversion region with BSIM4 compatible Vgsteff;
9. Multi-finger device with instance parameter NF;
10. A new instance parameter AGBCPD to improve gate current for body contact;
11. A new instance parameter DELVTO representing threshold voltage variation;
12. FRBODY is both instance/model parameter.
   BSIMSOIv4.2 up to v4.5 benefits from an extensive review of the code by the CMC
members. A significant number of code implement issues/ errors are resolved and fixed in these
versions through close interaction with many user companies. The voltage, temperature and
charge derivatives are reviewed and improved as well. We believe users will greatly benefit from
the improvements introduced in the latest version. In BSIMSOIv4.4 two new features were
added (Vb check in SOIMOD=2 and fringe capacitance model enhancement), compared to
BSIMSOIv4.3.1. The correlated thermal noise model along with many other improvements is
introduced in version 4.5.0.
Note that BSIMSOIv4.6.0 model might not be backward compatible with its previous versions
(BSIMSOIv4.4.0 or below).
   A typical PD SOI MOSFET structure is shown in Fig. 2.1. The device is formed on a thin
SOI film of thickness Tsi on top of a layer of buried oxide with thickness Tbox. In the floating
body configuration, there are four external biases which are gate voltage (Vg), drain voltage (Vd),
source voltage (Vs) and substrate bias (Ve). The body potential (Vb) is iterated in circuit
simulation. If a body contact is applied, there will be one more external bias, the body contact
voltage (Vp).
Tox
                           SOURCE                                    DRAIN
                                                                              Tsi
                                              Vb   BODY
Tbox
SUBSTRATE
Ve
   Since the backgate (Ve) effect is decoupled by the neutral body, PD SOI MOSFETs have
similar characteristics as bulk devices. Hence most PD SOI models reported [5, 6] were
developed by adding some SOI specific effects onto a bulk model. These effects include parasitic
bipolar current, self-heating and body contact resistance.
   BSIMPD is formulated on top of the BSIM3v3 framework. In this way, a lot of physical
effects which are common in bulk and SOI devices can be shared. These effects are reverse short
channel effect, poly depletion, velocity saturation, DIBL in subthreshold and output resistance,
short channel effect, mobility degradation, narrow width effect and source/drain series resistance
[1, 4].
    In BSIMPD, the floating body voltage is iterated by the SPICE engine. The result of iteration
is determined by the body currents [7, 18]. In the case of DC, body currents include diode
current, impact ionization, gate-induced drain leakage (GIDL), oxide tunneling and body contact
current. For AC or transient simulations, the displacement currents originated from the capacitive
coupling are also contributive.
    To ensure a good model behavior during simulations, the iterated body potential Vbs is
bounded by the following smoothing function
Here the body potential Vbsh is equal to the Vbs bounded between (Vbsc, s1), and is used in the
threshold voltage and bulk charge calculation. To validate the popular square root expression
   s  Vbsh in the MOSFET model, Vbsh is further limited to 0.95s to give the following effective
body potential
   Using the Vbseff which is clamped to the surface potential s, the square-root dependence
   s  Vbseff of the threshold voltage is ensured to behave properly during simulations [20].
However the real body potential may be larger than the surface potential in state-of-the-art PD
SOI technologies. To accurately count the body effect in such a high body bias regime, we
extend the square-root expression by
where a linear extrapolation is employed for Vbsh  0.95 s . Notice that sqrtPhisExt   s  Vbseff
The complete equation of the threshold voltage Vth can be found in the Appendix C.
 1  Keta Vbsh 
to accommodate the model behavior in the high body bias regime, which is important in PD SOI.
The parameter Ketas acts like an effective increment of the surface potential, which can be used
to adjust the Abulk rollup with the body potential Vbsh. While the other parameter Keta is used to
tune the rate of rollup with Vbsh. By using this new expression, the non-physical drain current
roll-off due to the dramatic Abulk rollup at high body bias can be avoided [20].
                                                *                                                  +
                                                                                   (           )
              ( )
                                                    (            )
                                                *                                                      +
                                                                                   (           )
             ( )
                                                    (            )
                  k BT  N gate 
Where, V fbsd        ln  20  for NGATE larger than 0, otherwise, V fbsd  0 .
                    q     10 
• rdsMod = 2 (Bias Dependent Internal Resistance, Rds(V))
                                                                     (√                √   )
          ( )
                                                         (              )
Where, The resistance Rs,geo and Rd,geo are simply calculated as the sheet resistance (RSH) times
the number of squares (NRS, NRD):
Rs,geo = NRS*RSH
Rd,geo = NRD*RSH
   After improving the Vth and Abulk behavior in the high body bias regime, we can describe the
MOSFET drain current by the same equation as BSIM3v3. The effective drain voltage Vdseff and
effective gate overdrive voltage Vgsteff (i.e., effective Vgse – Vth in Appendix C-5) introduced in
BSIM3v3 [1] are employed to link subthreshold, linear and saturation operation regions into a
single expression as
                                                   I ds 0         Vds  Vdseff
                               I ds ,MOSFET                 (1               )
                                                   Rds I dso          VA
                                                1
                                                    Vdseff
                                                         Weff
                                            eff Cox
                                                          Leff
                                                                 Vdseff       
                                     Vgsteff 1  Abulk                       Vdseff
                            Idso 
                                                            
                                                            2 Vgsteff         
                                                                         2vt 
                                                                                                     (2.7)
                                                             Vdseff
                                                     1
                                                            Esat Leff
Where, Vdseff is the effective source-drain bias (Appendix C-8), Rds is the source/drain series
resistance, eff is the mobility ( Users are suggested to check the details in Chap. 10 and
Appendix C), Esat is the critical electrical field at which the carrier velocity becomes saturated
and VA accounts for channel length modulation (CLM) and DIBL as in BSIM3v3. The substrate
current body effect (SCBE) [8, 9] on VA is not included because it has been taken into account
explicitly by the real floating body simulation determined by the body currents, which will be
detailed in the next chapter.
   Body currents determine the body potential and therefore the drain current through the body
effect. Beside the impact ionization current considered in BSIM3v3, diode (bipolar) current,
GIDL, oxide tunneling and body contact current are all included in the BSIMPD model [Fig. 3.1]
to give an accurate body-potential prediction in the floating body simulation [18].
Igb
Iii Idiode
                                                                       Vbs  
                                       I bs1  Wdios Tsi j difs  exp               1
                                                                                            
                                                                       ndiodesVt  
                                                                                                                        (3.1)
                                                                        Vbd  
                                       I bd 1  Wdiod Tsi j difd  exp                1
                                                                                              
                                                                        n dioded Vt    
Here ndiodes , jdifs ,Wdios , ndioded , jdifd ,Wdiod are the non-ideality factor, the saturation current, the
effective B-S diode width and the B-D diode width, respectively.
   The carrier recombination and trap-assisted tunneling current in the space-charge region is
modeled by
                                                  Vbs                 Vsb          Vrec0 s           
                I bs 2  Wdios Tsi j recs  exp                exp
                                                                      0.026n                           
                                               0.026n 
                                                      recfs               recrs Vrec0 s  V sb        
                                                                                                                        (3.2)
                                                    Vbd                     Vdb          Vrec0 d         
                I bd 2    Wdiod Tsi j recd  exp                    exp
                                                                            0.026n                         
                                                 0.026n           
                                                        recfd                   recrd Vrec0 d  Vdb       
Here nrecfs , nrecrs , jrecs , nrecfd , nrecrd , jrecd are non-ideality factors for forward bias and reverse bias,
the saturation current, respectively. Note that the parameters Vrec0 s , Vrec0 d are provided to model
the current roll-off in the high reverse bias regime.
   The reverse bias tunneling current, which may be significant in junctions with high doping
concentration, can be expressed as
                                                                Vsb            Vtun 0 s  
                             I bs 4  Wdios Tsi jtuns 1  exp                              
                                                                                                 
                                                                0.026ntuns Vtun 0 s  Vsb  
                                                                                                                        (3.3)
                                                                 Vdb             Vtun 0 d  
                             I bd 4  Wdiod Tsi jtund 1  exp                                 
                                                                                                    
                                                                 0.026n tund Vtun 0 d   V db  
where jtuns , jtund are the saturation currents. The parameters ntuns , ntund and Vtun 0 s , Vtun 0 d are
provided to better fit the data.
                                                      Vbs                
                         I bs 3  1   bjt I ens exp
                                                                                  1
                                                                            1
                                                      ndiodesVt            E hlis  1
                                                      Vbd                  
                         I bd 3  1   bjt I end exp
                                                                                    1
                                                                              1
                                                      n diodedVt             E hlid  1
                                                                                 N bjt
                                                            1     1 
                                  Weff' Tsi jbjts  Lbjt 0      
                                                                        
                         I ens
                                                          L      L
                                                             eff     n 
                                                                                  N bjt
                                                        1    1 
                                  W Tsi jbjtd  Lbjt 0     
                                                                  
                                       '
                         I end        eff               L
                                                       eff Ln 
                                                Vbs                  
                         E hlis  Ahlis _ eff exp                    1
                                                ndiodesVt             
                                                Vbd                   
                         E hlid  Ahlid _ eff exp                     1
                                                n diodedVt             
                                             Leff     
                                                             2
                                                                 
                          bjt    exp 0.5                                                   (3.4)
                                            Ln               
Here bjt is the bipolar transport factor, whose value depends on the ratio of the effective
channel length Leff and the minority carrier diffusion length Ln . jbjts and jbjtd are the saturation
currents, while the parameters Lbjt 0 and N bjt are provided to better fit the forward injection
characteristics. Notice that E hlis and E hlid , determined by the parameter Ahlis and Ahlid , stand for
the high level injection effect in the B-S/D diode, respectively.
   The parasitic bipolar transistor current is important in transient body discharge, especially in
pass-gate floating body SOI designs [7]. The BJT collector current is modeled as
                                              V           V           1
                         I c   bjt I en exp  bs   exp  bd  
                                              ndiodesVt   ndiodedVt   E2 nd
                                    Eely  Eely 2  4 Ehli
                         E2 nd                                                                     (3.5)
                                              2
                                        Vbs  Vbd
                         Eely     1
                                      VAbjt  Aely Leff
                         Ehli  Ehlis  Ehlid
BSIMSOIv4.6.0 Manual Copyright © 2017, UC Berkeley                                             Page 12
                                    Chapter 3: Body Currents Model
where E 2 nd is composed of the Early effect Eely and the high level injection roll-off E hli . Note
that E2nd  Eely as Eely  Ehli . While E2nd  Ehli as Ehli  Eely , in which case the Early
                                                           4                                           4
    To sum up, the total B-S current is I bs   I bsi , and the total B-D current is I bd   I bdi .
                                                          i 1                                        i 1
The total drain current including the BJT component can then be expressed as
                                               I ds,total  I ds,MOSFET  I c                                    (3.6)
    IiiMod = 0
    An accurate impact ionization current equation is crucial to the PD SOI model since it may
affect the transistor output characteristics through the body effect [11]. Hence in BSIMPD we
use a more recent expression [22] to formulate the impact ionization current Iii as
                                                                            Vdiff         
                        I ii   0 ( I ds , MOSFET  I ii _ BJT ) exp                     
                                                                       V  V        2
                                                                       2  1 diff  0 diff 
                                                               T         L 
                      Vdsatii  VgsStep  Vdsatii 0 1  Tii        1   ii 
                                                              Tnom       Leff 
                                                                                                                 (3.7)
                                 E satii Leff                1                   S V         
                      VgsStep                                           Sii 2  ii 0 gst 
                                1 E L                 1  S V                   1 S V
                                      satii eff             ii 1 gsteff               iid ds 
Here the Fbjtii I c term represents the contribution from the parasitic bipolar current. Notice that
the classical impact ionization current model [12] adopted in BSIM3v3 is actually a special case
of Eqn. (3.6) when  0 , 1 ,  2    1,0,0 . However, the dependence of log( I ii I ds ) on the drain
overdrive voltage Vdiff is quite linear [22] for state-of-the-art SOI technologies due to thermally
The extracted saturation drain voltage Vdsatii depends on the gate overdrive voltage Vgst and
Leff . One can first extract the parameters Vdsatii 0 , Lii  by the Vdsatii - Leff characteristics at Vgst  0 .
All the other parameters ( E satii , Sii1 , Sii 2 , Sii 0 , Siid ) can then be determined by the plot of Vdsatii
versus Vgs for different Leff . Notice that a linear temperature dependence of Vdsatii 0 with the
   IiiMod = 1
   When IiiMod = 0, the two component currents I ds,MOSFET and Ic have a same bias dependence
for impact ionization rate. This approximation generally won’t cause accuracy problem because
the MOSFET drain current is the major contribution on impact ionization current in the
interested operation regions. While SOI MOSFET device operates in subthreshold to
accumulation regions, parasitic BJT effect starts to dominant nodal drain current at high drain
bias. In order to model Iii better, IiiMod =1 is introduce to treat I ds,MOSFET and Ic separately. It
means that these two components have the different impact ionization rate [30].
   Here I ds,MOSFET still uses the old impact ionization model. The BJT contribution is expressed
gidlMod = 0
   GISL/GIDL can be important in SOI device because it can affect the body potential in the
low Vgs and high Vds regime.
   The formula for GIDL current is:
                                   Vds  Vgse  EGIDL  V fbsd            3  Toxe  BGIDL     Vdb3
    I GIDL  AGIDL Wdiod  Nf                                   exp                     
                                             3  Toxe                   Vds  Vgse  EGIDL  CGIDL  Vdb3
                                                                                           
(3.9)
Where, AGIDL, BGIDL, CGIDL, and EGIDL are model parameters and explained in Appendix
A. CGIDL accounts for the body-bias dependence of IGIDL and IGISL. Here Vgse accounts for
poly depletion effect.
   Following BSIM4, BSIMSOI4.1 also introduces GISL current. In order to model asymmetric
source/drain, GISL model has another set of parameters: AGISL, BGISL, CGISL, and EGISL.
                                Vds  Vgse  EGISL  V fbsd              3  Toxe  BGISL       Vsb3
I GISL  AGISL Wdios  Nf                                       exp                        
                                           3  Toxe                     Vds  Vgse  EGISL  CGISL  Vsb3
                                                                                             
                                                                                                        (3.10)
   gidlMod = 1
   In this new model, the basic idea is to decouple Vds and Vgs dependence by introducing an
extra parameter rgidl. The body bias dependence part is also revised. Here, KGIDL and FGILD
are Vbs dependent parameters.
                                         Vds  RGIDL Vgse  EGIDL  V fbsd                       (3.11)
        I GIDL  AGIDL  Wdiod  Nf 
                                                          3  Toxe
                           3  Toxe  BGIDL            KGIDL 
                   exp                         exp              
                         Vds  Vgse  EGIDL 
                                                       Vds  FGIDL 
                                        Vds  RGISL  Vgse  EGISL  V fbsd
        I GISL    AGISL Wdios  Nf 
                                                       3  Toxe
                           3  Toxe  BGISL          KGISL 
                   exp                       exp               
                         Vds  Vgse  EGISL 
                                                     Vbs  FGISL 
        Here Vfbsd = 0 when mtrlMod = 0.
   For thin oxide (below 20Å), oxide tunneling is important in the determination of floating-
body potential [20]. In BSIMPD the following equations are used to calculate the tunneling
current density Jgb :
In inversion,
                     J gb   A
                               V gbVaux  Toxref
                                        
                                                    
                                                    
                                                        N tox
                                                      exp 
                                                                                  
                                                             B α gb1  β gb1 Vox Tox 
                                                                                       
                                  Tox2  Toxqm     
                                                    
                                                           
                                                                1   V ox   V gb1
                                                                                       
                                                                                       
                                                Vox  φ g  
                 Vaux  VEVB         ln1  exp             
                                                VEVB  
                                                           
                              q3
                     A
                            8h b                                                             (3.12)
                            8 2mox    32
                     B
                                        b
                           3hq
                  b  4.2eV
                     mox  0.3m0
In accumulation,
        J gb   A
                  V gbVaux  Toxref
                           
                                              
                                              
                                                  N tox
                                                          exp
                                                                                      
                                                               B α gb2  β gb2 Vox Tox   
                                                                                           
                     Tox  Toxqm
                       2                      
                                              
                                                             
                                                                   1  Vox Vgb2           
                                                                                           
                                  V gb  V fb  
        Vaux  VECBVt ln 1  exp            
                        
                                     VECB  
             q3
        A
           8h b                                                                              (3.13)
                8     2mox  b3 2
        B
                  3hq
         b  3.1eV
        mox  0.4m0
Igb is evaluated in IgbMod=1. IgbMod=0 turns it off. Please see Appendix B for model
parameter descriptions.
  In BSIMSOI4.1, the instance parameter Agbcp2 represents the parasitic gate-to-body overlap
area due to the body contact. This parameter applies for the opposite-type gate, which is shown
Fig. 4.4. In order to account the tunneling current in this region, Ig_agbcp2 is introduced as
following:
Igc0, determined by ECB for NMOS and HVB (Hole tunneling from Valence Band)
for PMOS at Vds=0, is formulated as
           Igc0  Weff Leff  A  ToxRatio Vgse Vaux
                  exp   B  TOXE  AIGC  BIGC Voxdepinv   1  CIGC Voxdepinv                         (3.15)
where A = 4.97232 A/V2 for NMOS and 3.42537 A/V2 for PMOS, B = 7.45669e11
(g/F-s2)0.5 for NMOS and 1.16645e12 (g/F-s2)0.5 for PMOS, and
                                                       Vgse  VTH 0                                  (3.16)
                      Vaux  NIGC  vt  log 1  exp                
                                                       NIGC  vt  
Igs and Igd -- Igs represents the gate tunneling current between the gate and the
source diffusion region, while Igd represents the gate tunneling current between the
gate and the drain diffusion region. Igs and Igd are determined by ECB for NMOS
and HVB for PMOS, respectively.
  I gs  Weff DLCIG  A  ToxRatioEdge Vgs Vgs '                                                       (3.17)
        exp   B  TOXE  POXEDGE   AIGS  BIGS Vgs '   1  CIGS  Vgs '  
and
 I gd  Weff DLCIGD  A  ToxRatioEdge Vgd Vgd '                                       (3.18)
       exp   B  TOXE  POXEDGE   AIGD  BIGD  Vgd '   1  CIGD  Vgd '  
where A = 4.97232 A/V2 for NMOS and 3.42537 A/V2 for PMOS, B = 7.45669e11
(g/F-s2)0.5 for NMOS and 1.16645e12 (g/F-s2)0.5 for PMOS, and
                           TOXREF      
                                                      NTOX
                                                                         1               (3.19)
        ToxRatioEdge                                      
                        TOXE  POXEDGE                         TOXE  POXEDGE 
                                                                                     2
Vfbsd is the flat-band voltage between gate and S/D diffusions calculated as
If NGATE > 0.0
                                 kBT      NGATE                                        (3.22)
                      V fbsd        log          VFBSDOFF
                                  q       NSD 
Else Vfbsd = 0.0.
and
                      1   PIGCD  Vdseff  1  exp   PIGCD  Vdseff   1.0e  4    (3.24)
      Igcd  Igc0 
                                       PIGCD 2 Vdseff 2  2.0e  4
   In BSIMPD, a body resistor is connected between the body (B node) and the body contact (P
node) if the transistor has a body-tie. The body resistance is modeled by
                                         '
                                        W eff            '
                                                         W eff   
                          Rbp    
                                 Rbody          ||  R         , R       Rbsh N rb               (3.26)
                                       Leff      halo 2        bodyext
                                                              
Here Rbp and Rbodyext represent the intrinsic and extrinsic body resistance respectively. Rbody is
the intrinsic body sheet resistance, Rhalo accounts for the effect of halo implant, Nrb is the number
of square from the body contact to the device edge and Rbsh is the sheet resistance of the body
contact diffusion.
   The body contact current I bp is defined as the current flowing through the body resistor:
                                                         Vbp
                                           I bp                                                     (3.27)
                                                    Rbp  Rbodyext
where Vbp is the voltage across the B node and P node. Notice that I bp  0 if the transistor has a
floating body.
   The effective channel width may change due to the body contact. Hence the following
equations are used:
                                                                                                 (3.28)
                             Wdiod  Weff  Pdbcp
                                                '
Here dWbc is the width offset for the body contact isolation edge. N bc is the number of body
contact isolation edge. For example: N bc  0 for floating body devices, N bc  1 for T-gate
structures and N bc  2 for H-gate structures. Pdbcp / Psbcp represents the parasitic perimeter length
for body contact at drain/source side. The body contact parasitics [17] may affect the I-V
significantly for narrow width devices [20].
   After introducing all the mechanisms that contribute the body current, we can express the
nodal equation (KCL) for the body node as
                            Ibs  Ibd   Ibp  Iii   I dgidl  I sgisl   I gb  0          (3.29)
Eqn. (3.18) is important since it determines the body potential through the balance of various
body current components. The I-V characteristics can then be correctly predicted after this
critical body potential can be well anchored.
      Bias independent fringing capacitances are added between the gate and source as well as
       the gate and drain. A sidewall source/drain to substrate (under the buried oxide) fringing
       capacitance is added.
      A source/drain-buried oxide-Si substrate parasitic MOS capacitor is added.
      Body-to-back-gate coupling is added.
      Parasitic gate capacitance model is improved by the new body contact model.
   A good intrinsic charge model is important in bulk MOSFETs because intrinsic capacitance
comprises a sizable portion of the overall capacitance, and because a well behaved charge model
is required for robust large circuit simulation convergence. In analog applications there are
devices biased near the threshold voltage. Thus, a good charge model must be well-behaved in
transition regions as well. To ensure proper behavior, both the I-V and C-V model equations
should be developed from an identical set of charge equations so that Cij/Id is well behaved.
   A good physical charge model of SOI MOSFETs is even more important than in bulk. This is
because transient behavior of the floating body depends on capacitive currents [18]. Also, due to
the floating body node, convergence issues in PD SOI are more volatile than in bulk, so that
charge smoothness and robustness are important. An example is that a large negative guess of
body potential by SPICE during iterations can force the transistor into depletion, and a smooth
transition between depletion and inversion is required. Therefore the gate/source/drain/backgate
to body capacitive coupling is important in PD SOI.
   To ensure charge conservation, terminal charges instead of terminal voltages are used as state
variables. The terminal charges Qg, Qd, Qs, Qb, and Qe are the charges associated with the gate,
drain, source, body, and substrate respectively. These charges can be expressed in terms of
inversion charge (Qinv), front gate body charge (QBf), source junction charge (Qjs) and drain
junction charge (Qjd). The intrinsic charges are distributed between the nodes as shown in Fig.
4.1. The charge conservation equations are:
                                   QBf  Qac0  Qsub0  Qsubs
Qg  Qinv  QBf 
Qb  QBf  Qe  Q js  Q jd (4.1)
Qs  Qinv ,s  Q js
Qd  Qinv ,d  Q jd
Qg  Qe  Qb  Qs  Qd  0
   The front gate body charge (QBf) is composed of the accumulation charge (Qac0) and the bulk
charge ( Q sub0 and Q subs ), which may be divided further into two components: the bulk charge at
Vds=0 (Qsub0), and the bulk charge induced by the drain bias (Qsubs) (similar to Qsub in
BSIM3v3).
   All capacitances are derived from the charges to ensure charge conservation. Since there are
5 charge nodes, there are 25 (as compared to 16 in BSIM3v3) components. For each component:
                                                                              C  C
        dQi
Cij         , where i and j denote transistor nodes. In addition,                     ij       ij   0.
        dV j                                                                    i           j
BSIMPD uses similar expressions to BSIM3v3 for Q inv and Q Bf . First, the bulk charge
vgstcvMod = 0 or 1
 The effective CV Vgst is defined as
                                                       Vgs  Vth       delvt  
                           VgsteffCV  nvt ln 1  exp             exp                                  (4.5)
                                              
                                                       nvt             nvt  
 vgstcvMod = 0 and 1 use the same VgsteffCV definition. As mentioned above, the only difference
between vgstcvMod = 0 and 1 is that Mod =1 fixes the bug in the code. Users are suggested to
choose vgstcvMod =1 or 2.
vgstcvMod = 2
 This new VgsteffCV follows that in IV model. There are two new model parameters MINVCV
and VOFFCV, which are binnable.
                                                 m*CV (Vgs _ eff  Vth  delvt ) 
                                 nvt ln 1  exp(                                )
                                                              nvt                                      (4.6)
VgsteffCV 
                                    2 s            (1  m )(Vgs _ eff  Vth  delvt )  VoffCV
                                                          *CV
where Wactive and Lactive are the effective channel width and length in CV, respectively. The
channel partition can be set by the Xpart parameter. The exact evaluation of source and drain
charges for each partition option is presented in Appendix C.
A parameter VFBeff is used to smooth the transition between accumulation and depletion
The physical meaning of the function is the following: it is equal to Vgb for Vgb<VFB, and
equal to VFB for Vgb>VFB. Using VFBeff, the accumulation charge can be calculated as
                           Qac0  FbodyWactive LactiveBCox (VFBeff  V fb )                                        (4.11)
where LactiveB  Lactive  DLCB . Notice that the parameters Fbody and DLCB are provided to give
a better fit for the SOI-specific history dependence of the body charge [14].
       The gate-induced depletion charge and drain-induced depletion charge can be expressed as
                                               K1eff         4(Vgs  VFBeff  VgsteffCV  Vbseff ) 
                                                    2
                                                                  V                            2
                                                                                      AbulkCV VdsCV          
           Q subs  FbodyWactive LactiveB K1eff Cox 1  AbulkCV  dsCV                                    
                                                                           12V gsteffCV  AbulkCV VdsCV 2 
                                                                                                                    (4.13)
                                                                   2
respectively.
where LactiveBG  LactiveB  2Lbg . The parameter Lbg is provided to count the difference of LactiveB
For capMod=3, the flat band voltage is calculated from the bias-independent threshold
voltage, which is different from capMod=2. For the finite thickness formulation, refer to Section
Beside the junction depletion capacitance considered in BSIM3v3, the diffusion capacitance,
which is important in the forward body-bias regime [20], is also included in BSIMPD. The
source/drain junction charges Q jswg / Q jdwg can therefore be expressed as
The depletion charges Qbsdep / Qbddep have similar expressions as in BSIM3v3 [Appendix C].
            Weff '                               1         
                                                                N dif
                                                                       V  
                                                         1                             1
Qbsdif           Tsi J sbjt 1  Ldif 0  Lbj 0          exp  bs   1
                                                          
            N seg
                                                 Leff Ln      ndiosVt   Ehlis  1
                                                                                                    (4.16)
            Weff '                               1         
                                                                N dif
                                                                       V  
                                                          1                             1
Qbddif           Tsi J dbjt 1  Ldif 0  Lbj 0          exp  bd   1
                                                 Leff Ln    
            N seg
                                                                ndiodVt   Ehlid  1
The parameter  represents the transit time of the injected minority carriers in the body. The
parameters Ldif 0 and N dif are provided to better fit the data.
Expressions for extrinsic (parasitic) capacitances that are common in bulk and SOI
MOSFETs are taken directly from BSIM3v3. They are source/drain-to-gate overlap capacitance
[Fig. 4.2].
Cessw
Cesb
          Fig. 4.2          SOI MOSFET extrinsic charge components. Cessw is the substrate-to-
          source sidewall capacitance. Cesb is the substrate-to-source bottom capacitance.
with a bias dependent capacitance. If Vs,d=0, this MOS structure might be in accumulation.
However, if Vs,d=Vdd, the MOS structure is in depletion with a much smaller capacitance,
because the Si substrate is lightly doped. The bias dependence of this capacitance is similar to
high frequency MOS depletion capacitance as shown in Fig. 4.3. It might be substantial in
devices with large source/drain diffusion areas. BSIMPD models it by piece-wise expressions,
with accurately chosen parameters to achieve smoothness of capacitance and continuity to the
second derivative of charge. The substrate-to-source bottom capacitance (per unit source/drain
Physical parameters Vsdfb (flat-band voltage of the MOS structure) and Vsdth (threshold voltage of
the MOS structure) can be easily extracted from measurement. Cmin should also be extracted
from measurement, and it can account for deep depletion as well. Asd is a smoothing parameter.
The expression for Cedb is similar to Cesb. Fig. 4.3 shows the comparison of the model and
measured Cesb.
                                                                            measured data
                                                                            model fit
                                    160
                 Capacitance (fF)
                                    140
120
100
                                    80
                                            -4                -2                  0                2   4
                                                                             Vs/d,e
Finally, the sidewall source/drain to substrate capacitance (per unit source/drain perimeter
which depends on the silicon film thickness Tsi and the buried oxide thickness Tbox . The
parameter C sdesw represents the fringing capacitance per unit length. CfrCoeff has a default value
= 1, and is limited to a value of 2 (introduced in v4.4).
       The parasitic capacitive coupling due to the body contact is considered in BSIMPD. The
instance parameter Agbcp represents the parasitic gate-to-body overlap area due to the body
contact, and Aebcp represents the parasitic substrate-to-body overlap area. The effect may be
Note: There are four instance parameters used to calculate parasitic capacitances associated
with body contacts. They are: psbcp, pdbcp, agbcp and aebcp. It is worth pointing out that psbcp
and pdbcp represent additional gate perimeter to the source and drain and must be specified on a
per finger basis, while agbcp and aebcp represent addition gate area and addition area of body
BSIMSOI4.1 also considers the P+ implantation for body contact (as shown in Figure 4.4),
In BSIMSOI4.0, the instance parameter Agbcp represents the parasitic gate-to-body overlap
area due to the body contact. This parameter only applies for the same-type gate. For the
opposite-type gate, the charge will be overestimated by Agbcp. Charge model has to be modified
The higher VFB in the P+/P region lowers the gate charge and the net gate charge is the sum of
N+/P and P+/P regions as shown below. One new instance parameter Agbcp2 is introduced to
account for the opposite-type parasitic capacitance. The final charge could be expressed as
following:
 Total Charge = WL  N  / NMOS  Agbcp  N  / NMOS  Agbcp 2  P / NMOS                   (4.19)
Note: In this case, there is a new instant parameters agbcp2, which is similar to agbcp and
      mtrlMod=0
      The charge thickness introduces a capacitance in series with Cox, resulting in an effective
Coxeff. Based on numerical self-consistent solution of Shrődinger, Poisson and Fermi-Dirac
equations, universal and analytical XDC models have been developed. Coxeff can be expressed as:
                                               Coxp  Ccen                                    (4.20)
                                    Coxeff 
                                               Coxp  Ccen
where
Ccen   si / X DC (4.21)
                    1                    NDEP 
                                                     0.25
                                                             Vgse  Vbseff  VFBeff               (4.22)
            X DC    Ldebye exp  ACDE        16 
                                                                                   
                    3                   2 10                   TOXP            
where Ldebye is Debye length, and XDC is in the unit of cm and (Vgse - Vbseff - VFBeff) / TOXP is in
units of MV/cm. For numerical stability, (4.22) is replaced by (4.23)
                           X DC  X max 
                                              1
                                              2
                                                
                                                X 0  X 02  4 x X max                           (4.23)
where
                                        X 0  X max  X DC   x                                  (4.24)
mtrlMod = 1
                               3.9                                              (4.28)
              TOXP  EOT             X DC V VDDEOT ,V V 0
                             EPSRSUB         gs         ds bs
  With the calculated TOXP, XDC could be obtained at different gate voltage, just like
mtrlMod=0.
   Self-heating in SOI is more important than in bulk since the thermal conductivity of silicon
dioxide is about two orders of magnitude lower than that of silicon [15]. It may degrade the
carrier mobility, increase the junction leakage [20], enhance the impact ionization rate [24], and
therefore affect the output characteristics [16] of floating-body SOI devices.
5.1.   Temperature Dependence
   The temperature dependence of threshold voltage, mobility, saturation velocity and series
resistance in BSIMSOI is identical to BSIM3v3. However a different temperature dependence of
diode characteristics is adopted in BSIMSOI4.0:
                                                Eg (300 K )           T   
                            jsbjt  isbjt exp                X bjt 1      
                                               ndiodesVt           Tnom    
                                                Eg (300 K )           T    
                            jdbjt  idbjt exp                X bjt 1       
                                               ndiodedVt           Tnom     
                                               Eg (300 K )           T    
                           jsdif  isdif exp                X dif 1       
                                              ndiodesVt           Tnom     
                                                Eg (300 K )           T     
                            jddif  iddif exp                X dif 1        
                                               ndiodedVt           Tnom      
                                               Eg (300 K )           T    
                           jsrec  isrec exp                X rec 1       
                                              nrecf 0 sVt         Tnom     
                                                Eg (300 K )           T     
                            jdrec  idrec exp                X rec 1        
                                               nrecf 0 dVt         Tnom      
                                                            T       
                                  jstun  istun exp  X tun        1 
                                                           Tnom     
                                                        T      
                              jdtun  idtun exp  X tun       1                         (5.1)
                                                       Tnom  
                                                                    T       
                                     nrecrs  nrecr 0 s 1  ntrecr        1 
                                                                   Tnom     
                                                                    T       
                                     nrecrd  nrecr 0 d 1  ntrecr        1 
                                                                   Tnom     
                                                                        T       
                                       nrecfs  nrecf 0 s 1  ntrecf          1 
                                                                       Tnom     
                                                                        T       
                                     nrecfd  nrecf 0 d 1  ntrecf            1 
                                                                       Tnom     
The parameters isbjt , idbjt , isdif , iddif , isrec , idrec , istun , idtun are diode saturation currents at the nominal
temperature Tnom , and the parameters X bjt , X dif , X rec , X tun are provided to model the temperature
dependence. Notice that the non-ideality factors nrecfs , nrecfd , nrecrs , nrecrd are also temperature
dependent.
where R th 0 and C th 0 are normalized thermal resistance and capacitance, respectively. Wth0 is the
minimum width for thermal resistance calculation [19]. Notice that the current source is driving a
current equal to the power dissipated in the device.
P  I ds  Vds (5.3)
   To save computation time, the turn-on surface potential s (Phi) is taken to be a constant
within each timepoint because a lot of parameters (e.g. Xdep) are function of s. Each timepoint
will use a s calculated with the temperature iterated in the previous timepoint. However this
approximation may induce error in DC, transient and AC simulation. Therefore, it is a tradeoff
between accuracy and speed. The error in DC or transient is minimal if the sweeping step or time
step is sufficiently small.
FD SOI MOSFETs
   Using BSIMPD as a foundation, we have developed a unified model for both PD and FD SOI
circuit designs based on the concept of body-source built-in potential lowering [20, 25].
                                 0.5               Vbi
                       VBS (V)   0.4
0.3
0.2
                                 0.1                               VGS=0.5V
                                                                   L=0.5m
                                 0.0                               TSi=40nm
VDS (V)
Fig. 6.1 The body potential in the unified model approaches the VBS solved in BSIMPD for PD
devices, while returns to Vbi for ideal FD devices [20].
This unified model shares the same floating-body module as BSIMPD, with a generalized diode
current model considering the body-source built-in potential lowering effect (IBS  exp(-
qVbi/kT)). Therefore, an accurate and efficient Vbi model is crucial. The following
formulation for Vbi is mainly based on the Poisson equation and the physical characterization
for Vbi, as presented in [25].
    In order to keep backward compatibility, a new model selector fdMod is introduced. Here,
fdMod = 0 is the old Vbi formulation, while fdMod = 1 is the new one that is easier to fit.
  fdMod = 0
   For a given surface band bending  (source reference), Vbi can be formulated by applying
the Poisson equation in the vertical direction and continuity of normal displacement at the back
interface:
                                                                  
     Vbi   
                        C Si
                   C Si  C BOX
                                       
                                             qN ch
                                              
                                                                          
                                                    TSi  VDIBL   e Leff
                                                        2                          C BOX
                                                                                             VbGS  VFBb 
                                            2  Si                            C Si  C BOX
                                                                                                                  (6.1).
                             Si                OX              OX
                   C Si           , C BOX           , COX 
                            TSi                TBOX             TOX
The first term of Equation (6.1) represents the frontgate coupling. TSi is the SOI thickness. Nch
accounts for the effective channel doping, which may vary with channel length due to the non-
                                       ch 2               qN
uniform lateral doping effect. Here, 2 TSi is band bending in the body due to depletion
                                       si
charges, which is limited to (Eg-0.1) eV in v4.4. In SOIMOD=2, for any combinations of TSi and
Nch, if this term exceeds this limit, Nch is lowered accordingly. The second term of Equation (6.1)
represents the backgate coupling (VbGS). VFBb is the backgate flatband voltage. Equation (6.1)
shows that the impact of frontgate on Vbi reaches maximum when the buried oxide thickness,
TBOX, approaches infinity.
   In Equation (6.1), VDIBL represents the short channel effect on Vbi,
                                        Leff                 L              
          VDIBL  Dvbd 0  exp  Dvbd1        2 exp  Dvbd1 eff              Vbi  2 B                (6.2),
                                          2l                  l             
                                                                             
as addressed in [25]. Here l is the characteristic length for the short-channel-effect calculation.
Dvbd0 and Dvbd1 are model parameters. Similarly, the following equation
                                                       Leff                        
          e Leff   K1b  K2b   exp  Dk 2b
                                                                                L
                                                                2 exp  Dk 2b eff                         (6.3)
                                                                                    
                                                        2l                   l     
is used to account for the short channel effect on the backgate coupling, as described in [25].
DK1b, DK2b, K1b (default 1) and K2b (default 0) are model parameters.
fdMod = 1
   However, the two length-dependent functions (i.e., Eqr (6.2) and (6.3)) in Vbi model make
the parameter extraction difficult. Thus, BSIMSOI4.1 introduces a new Vbi equation as
following:
   CDSBS is the new model parameter representing the capacitance of drain to the body-source
potential. ∆VSCE is the length dependence of the capacitance coupling from drain. VSCE is the
new model parameter for SCE of ∆Vbi at zero Vds.
                               Leff                                   Leff      
VSCE  DVBD0   exp   DVBD1                        2 exp   DVBD1              Vds  VSCE 
                               2l                                      l                                           (6.4)
   If body contact devices are available, a direct probe of ∆Vbi can be achieved by finding the
onset of the external body bias after the channel current (threshold voltage) of FD device is
modulated.
   If body contact devices are not available, the length dependence related parameters of ∆Vbi
will be set to the value of SCE parameters in VT equation.
                                            Dvbd 0  DVT 0                                                                         (6.5)
                                            Dvbd1  DVT 1
The surface band bending, , is determined by the frontgate VGS and may be approximated by
                   ON    for VGS  VT
                                                                                                                      (6.6).
                                                               VT  VGS  for VGS  VT
                                    COX
                  ON 
                                
                          COX  C Si
                                       1
                                             C BOX     
                                                      1 1
To improve the simulation convergence, the following single continuous function from
subthreshold to strong inversion is used:
Here Vgs_eff is the effective gate bias considering the poly-depletion effect. VT,FD is the threshold
voltage at VBS = Vbi(=2B). NOFF,FD (default 1) and VOFF,FD (default 0) are model parameters
introduced to improve the transition between subthreshold and strong inversion. Vt is the thermal
voltage. Notice that the frontgate coupling ratio in the subthreshold regime approaches 1 as TBOX
approaches infinity.
   To accurately model Vbi and thus the device output characteristics, the surface band bending
at strong inversion, ON, is not pinned at 2B. Instead, the following equation
                                               
                           Vgsteff .FD Vgsteff , FD  2 K1 2 B
       ON  2 B  vt ln 1 
                                                                                             (6.8)
                                       moin  K1 vt 2                       
                                                                             
is used to account for the surface potential increment with gate bias in the strong inversion
regime [4]. Here moin is a model parameter. K1 is the body effect coefficient. Notice that a
single continuous function,
6.2. Verification
   The BSIMPD parameter extraction methodology presented in [20] may still be used under the
unified BSIMSOI framework, provided that the link between PD and FD, Vbi, can be accurately
extracted. As described in [25], a direct probe of Vbi can be achieved by finding the onset of the
external body bias (through a body contact) after which the threshold voltage and hence the
channel current of the FD SOI device is modulated. When the body contact is not available,
nevertheless, model parameters related to Vbi should be extracted based on the subthreshold
    characteristics of the floating-body device. As shown in Figure 6.2, the reduction of Vbi with
    backgate bias is responsible for the transition from the ideal subthreshold swing (~ 60 mV/dec. at
    room temperature) to the non-ideal one.
           Figure 6.2 clearly shows that the PD/FD transition can be captured by the Vbi approach. In
    other words, Vbi is indeed an index of the degree of full depletion, as pointed out in [20, 25]. As
    shown in Figure 6.3, larger floating-body effect can be observed for negative backgate bias due
    to smaller Vbi. In case the Vbi value is raised by charge sharing as described in [25], it can be
    predicted that the short-channel device should exhibit less floating-body effect than the long-
    channel one due to larger Vbi, as verified in Figure 6.4.
         0.0020
                LG=0.5m                                                      -4   LG=0.5m
                line: model                   VGS=1.5V
                                                                        10
                                                                                   VDS=0.05V
                    VbGS=0V                                                   -5
                                                                        10              o
                    VbGS=-1.5V
                                                                                   T=27 C
         0.0015                                                               -6
                                                                        10
                                                                              -7
                                                                                     ~67mV/dec.
                                                                        10
                                                  1.2V
                                                               ID (A)
ID (A)
                                                                              -8
         0.0010                                                         10                         ~102mV/dec.
                                                                              -9
                                                                        10                                      VbGS=4V
                                                                             -10                                  2V
                                              0.9V                      10
         0.0005                                                                                                   0V
                                                                             -11
                                                                        10                                       -2V
                                           0.6V                         10
                                                                             -12                                 -4V
                                                                             -13
                                                                                                          line: model
         0.0000                                                         10
              0.0     0.3   0.6      0.9     1.2         1.5                  -0.5          0.0     0.5      1.0      1.5
                                 VDS (V)                                                          VGS (V)
(Left) Fig. 6.2 The PD/FD transition can be captured by modeling Vbi [20].
    (Right) Fig. 6.3 Larger floating-body effect can be seen for the negative backgate bias (source
    reference) due to smaller Vbi [20].
Fig. 6.4 Less floating-body effect can be seen for the short-channel device due to larger Vbi
[20].
If SoiMod=1 (unified model for PD&FD) or SoiMod=2 (ideal FD), the following equations (FD
module) are added on top of BSIMPD.
   Vbs 0 
                    C Si          
                                 phi 
                                                 
                                          qN ch 1  N LX Leff                             
                                                               TSi  Vnonideal  V DIBL    e
                                                                   2                                   C BOX
                                                                                                                 Ves  VFBb 
             C Si    C BOX                      2 Si                                           C Si  C BOX
                        Si                OX                  OX
    where C Si               , C BOX             , C OX 
                       TSi                TBOX                 TOX
                                  Leff                 L 
   V DIBL  Dvbd 0  exp  Dvbd1        2 exp  Dvbd1 eff    Vbi  2 B 
                                    2l                  l  
                                                
                                                                               Leff                 L       
                                    e  K 1b  K 2b   exp  Dk 2b                  2 exp  Dk 2b eff    
                                                           
                                                                                2l         
                                                                                                        l      
                                                                                                                
                                                           
                              V gsteff .FD V gsteff ,FD  2 K 1 2 B
         phiON  2 B  Vt ln 1 
                                                                                             ,
                                         MoinFD  K 1  Vt
                                                               2                             
                                                                                            
Here Nch is the channel doping concentration. NLX is the lateral non-uniform doping coefficient
to account for the lateral non-uniform doping effect. VFBb is the backgate flatband voltage. Vth,FD
is the threshold voltage at Vbs=Vbs0(phi=2B). vt is thermal voltage. K1 is the body effect
coefficient.
If SoiMod=1, the lower bound of Vbs (SPICE solution) is set to Vbs0. If SoiMod=2, Vbs is pinned
at Vbs0. Notice that there is no body node and body leakage/charge calculation in SoiMod=2.
The zero field body potential that will determine the transistor threshold voltage, Vbsmos, is then
calculated by
The subsequent clamping of Vbsmos will use the same equation that utilized in BSIMPD. Please
download the BSIMPD manual at (http://bsim.berkeley.edu/models/bsimsoi).
If SoiMod=3 is specified, BSIMSOI will select the operation mode for the user based on the
estimated value of Vbs0 at phi=2B (bias independent), Vbs0t:
       If Vbs0t > Vbs0fd, BSIMSOI will be in the ideal FD mode (SoiMod=2).
       If Vbs0t < Vbs0pd, BSIMSOI will be in the BSIMPD mode (SoiMod=0).
       Otherwise, BSIMSOI will be operated under SoiMod=1.
Notice that both Vbs0fd and Vbs0pd are model parameters.
BSIMSOI4.1 provides the gate resistance model and body resistance model for devices used in
RF application.
Users have four options for modeling gate electrode resistance (bias independent) and intrinsic-
input resistance (Rii, bias-dependent) by choosing model choice parameter rgateMod.
RgateMod = 0 (zero-resistance):
RgateMod = 1 (constant-resistance):
Rgeltd
In this case, only the electrode gate resistance (bias-independent) is generated by adding an
internal gate node. The electrode gate resistance Rgeltd is given by
                               Weff       
         RSHG   XGW                    
                        3  NGCON  NSEG 
Rgeltd                                                                                   (7.1)
             NGCON  L drawn  XGL
                                        Rgeltd+
                                        Rii
In this case, the gate resistance is the sum of the electrode gate resistance and the intrinsic-input
                                       Rgeltd
                                                        Rii
Cgso Cgdo
RbodyMod = 0
In this case, body resistance network turns off. RF data still could be fit for fully depleted SOI
device [28].
RbodyMod =1
A two-resistance body resistance network turns on as shown in the following figure.
Two extra nodes sbNode and dbNode are introduced in this case. The body resistor
RBSB/RBDB are located between sbNode/dbNode and bNode. As in BSIM4, a minimum
conductance, GBMIN, is introduced in parallel with each resistance and therefore to prevent
infinite resistance values, which would otherwise cause poor convergence.
Note that the intrinsic model body reference point in this case is the internal body node bNode,
into which the impact ionization current Iii and the GIDL current IGIDL flow.
                                             R
                                           sb bdb
      The physical mechanism for the flicker noise is trapping/de-trapping related charge
      fluctuation in oxide traps, which results in fluctuations of both mobile carrier numbers and
      mobility in the channel. The unified flicker noise model captures this physical process.
(8.2)
Where  eff is the effective mobility at the given bias condition, and Leff and Weff are the
   effective length and width respectively. The parameter N 0 is the charge density at the source
   side given by:
                                              CoxVgsteff                                    (8.3)
                                    N0 
                                                   q
The parameter N l is the charge density at the source side given by:
   N  is given by:
                                k BT  (Cox  Cd  CIT )                                    (8.5)
                        N 
                                                                q2
Lclm is the channel length reduction due to channel length modulation and given by:
where Rds is the source/drain resistance, and the parameter NTNOI is introduced for more
      accurate fitting of short-channel devices. Qinv is the inversion channel charge computed from
      the capacitance models
      G mbs as well as the induced-gate noise with partial correlation to the channel thermal noise
      are all captured in the new “noise partition” model.
The noise voltage source partitioned to the source side is given by:
                                                      Vdseff f                                 (8.8)
                                vd2  4kBT tnoi
                                              2
                                                  
                                                         I ds
   and the noise current source put in the channel region with gate and body amplification is
   given by:
                Vdseff f                                                                       (8.9)
                            Gds  tnoi   Gm  Gmbs   vd2   Gm  Gds  Gmbs 
                                                            2
   id2  4kBT
                                                                                          2
I ds
   where
                                                V                  2
                                                                                              (8.10)
              tnoi  RNOIB  1  TNOIB  Leff  gsteff            
                                               E L                  
                                                sat eff            
                                                V                
                                                                    2
       The parameter NTNOI is added to give the flexibility to tune the magnitude of noise
   density.
          tnoiMod = 3
       Unlike tnoiMod=1, in this thermal noise model both the gate and the drain noise are
       implemented as current noise sources. The drain current noise flows from drain to
       source; whereas the induced gate current noise flows from the gate to the source and
       drain. The correlation between the two noise sources is independently controllable and
       can be tuned using the parameter RNOIC, although the use of default value 0.395 is
       recommended when measured data is not available. The relevant formulations of
       tnoiMod=3 are given below.
(8.12)
(8.13)
(8.14)
(8.15)
(8.16)
(8.17)
(8.18)
                               *                           (   ) +
                                                                          (8.19)
                                               (           )
                                       √                                  (8.20)
                              [                            (    ) ]
                                                                          (8.21)
                              [                            (    ) ]
                                                                          (8.22)
(8.23)
( ) (8.24)
(8.25)
                                                                          (8.26)
                                   √                   ⁄
( ) ( | |) (8.27)
( ) ( ) (8.28)
( ) ( ) (8.29)
  The mechanical stress effect induced by process causes the performance of MOSFET to be
function of the active area size (OD: oxide definition) and the location of the device in the active
area. The necessity of new models to describe the layout dependence of MOS parameters due to
stress effect becomes very urgent in advance CMOS technologies. Influence of stress on mobility
has been well known since the 0.13um technology. The stress influence on saturation velocity is
also experimentally demonstrated. Stress-induced enhancement or suppression of dopant
diffusion during the processing is reported. Since the doping profile may be changed due to
different STI sizes and stress, the threshold voltage shift and changes of other second-order
effects, such as DIBL and body effect, were shown in process integration.
   Experimental analysis shows that there exist at least two different mechanisms within the
influence of stress effect on device characteristics. The first one is mobility related which is
induced by the band structure modification. The second one is Vth related as a result of doping
profile variation. Both of them follow the same 1/LOD trend but reveal different L and W
scaling. A BSIM4 compatible phenomenological stress model based on these findings has been
developed by modifying some parameters. Note that the following equations have no impact on
the iteration time because there are no voltage-controlled components in them.
  eff
           1    eff                                                                   (9.2)
 eff 0
Figure (9.1) shows the typical layout of a MOSFET on active layout surrounded by STI
isolation. SA, SB are the distances between isolation edge to Poly from one and the other side,
respectively [27]. 2D simulation shows that stress distribution can be expressed by a simple
function of SA and SB. Figure (9.2) shows the schematic stress distribution in the OD region
[29].
Assuming that mobility relative change is proportional to stress distribution. It can be described
as function of SA, SB(LOD effect), L, W, and T dependence.
             KU 0
                       Inv _ sa  Inv _ sb                                                           (9.3)
   eff
          Kstress _ u 0
                                1                              1
where Inv _ sa                            , Inv _ sb                    ,
                         SA  0.5  Ldrawn              SB  0.5  Ldrawn
                             LKU 0                        WKU 0                                             
                1  ( L                                                                                    
                        drawn  XL)             (Wdrawn  XW  WLOD)
                                    LLODKU 0                         WLODKU 0
Kstress _ u 0                                                                                              
                                              PKU 0                                    Temperature     
                                                                                                           
                                                                         1  TKU 0  
                                                                  WLODKU 0 
                                                                                                       1  
                 ( Ldrawn  XL)            (Wdrawn  XW  WLOD)                        TNOM           
                                  LLODKU 0
                                                                           
So that
where eff 0 , vsattemp 0 are low field mobility and low field saturation velocity at SAref , SBref .
SAref , SBref are reference distances between OD edge to poly from one and the other side.
                  NF 1
              1                        1
Inv _ sb          SB  0.5  L
             NF   i 0           drawn  i  ( SD  Ldrawn )
  In BSIMSOI4.1, a new global selector is introduced to turn on or of the new material models,
which are important for the advanced CMOS technology. When users select mtrlMod = 1, the
new materials (such as high k/metal gate) could be modeled. The default value (mtrlMod = 0)
maintains the backward compatibility.
10.1 Non-Silicon Channel
  With the three new parameters, the temperature-dependent band gap and
intrinsic carriers in non-silicon channel are described as follow:
                                          TBGASUB  Tnom 2                      (10.1)
                    Eg 0  BG 0SUB 
                                          Tnom  TBGBSUB
                                                      Eg (300.15)  Eg 0      (10.3)
                                        3/ 2
                            Tnom 
            ni  NI 0SUB                     exp                     
                            300.15                         2vt         
                                Eg 0                      Eg 0          NSD      (10.7)
  V fbsd  PHIG  ( EASUB            B 4SOItype  MIN       , vt ln       
                                 2                        2             ni  
Here B4SOItype is defined as +1 for nMOS and -1 for pMOS.
This new flat band equation improves the GIDL/GISL models as following:
                                 Vds  Vgse  EGIDL  V fbsd                         (10.8)
   I GIDL  AGIDL  WeffCJ  Nf 
                                             EPSRSUB
                                     EOT 
                                                3.9
                                           EPSRSUB           
                                 EOT         3.9
                                                      BGIDL 
                                                                   Vdb3
                            exp                              
                                 Vds  Vgse  EGIDL  V fbsd  CGIDL  Vdb
                                                                          3
                                                             
                                 Vds  Vgse  EGISL  V fbsd                         (10.9)
   I GIDS  AGISL WeffCJ  Nf 
                                             EPSRSUB
                                     EOT 
                                                3.9
                                            EPSRSUB           
                                  EOT         3.9
                                                        BGISL 
                                                                    Vdb3
                             exp                             
                                  Vds  Vgse  EGISL  V fbsd  CGISL  Vdb
                                                                           3
 
Furthermore, for mtrlMod=1 the mobility degradation uses the new expression of the vertical
field in channel as following:
                                                                                                              (10.10)
          Vgsteff  2Vth  2  B 4SOItype  ( PHIG  EASUB  Eg / 2  0.45)                           3.9
 Eeff                                                                                          
                                                EOT                                                 EPSRSUB
          mobMod=2
                                                      o                                                  (10.12)
             eff 
                                                Vgsteff  U d              Vgsteff  U d
                      1  (U a  U cVbseff )(                   )  Ub (                   )2
                                                    Tox                           Tox
             U d  2  B 4 SOItype  ( PHIG  EASUB  Eg / 2  0.45)
          mobMod=3
                                                       0                                                     (10.13)
                         eff 
                                  1  [U a Eeff  U b Eeff 2 ](1  U cVbseff )
Mname <D node> <G node> <S node> <E node> [P node]
           [B node] [T node] <model>
           [L=<val>] [W=<val>]
           [AD=<val>] [AS=<val>] [PD=<val>] [PS=<val>]
           [NRS=<val>] [NRD=<val>] [NRB=<val>]
           [OFF][BJTOFF=<val>]
           [IC=<val>,<val>,<val>,<val>,<val>]
           [RTH0=<val>] [CTH0=<val>]
           [DEBUG=<val>]
           [DELVTO=<val>]
           [SA=<val>][SB=<val>][SD=<val>]
           [NF=<val>]
           [NBC=<val>] [NSEG=<val>] [PDBCP=<val>] [PSBCP=<val>]
           [AGBCP=<val>][AEBCP=<val>][VBSUSR=<val>][TNODEOUT]
           [FRBODY=<val>][AGBCPD=<val>][SHMOD=<val>]
Description
<D node>            Drain node
<G node>            Gate node
<S node>            Source node
<E node>            Substrate node
[P node]            (Optional) external body contact node
[B node]            (Optional) internal body node
[T node]            (Optional) temperature node
<model>             Level 9 BSIM3SOI model name
[L]                 Channel length
[W]                 Channel width
BSIMSOIv4.6.0 Manual Copyright © 2017, UC Berkeley                Page 62
                        Appendix A: Model Instance Syntax
[VBSUSR]                 Optional initial value of Vbs specified by user for transient analysis
[TNODEOUT]               Temperature node flag indicating the usage of T node
[FRBODY]                 Layout-dependent body resistance coefficient
[AGBCPD]                 Parasitic gate-to-body overlap area for body contact in DC
[RBDB]                   Resistance between bNode and dbNode
[RBSB]                   Resistance between bNode and sbNode
There are three optional nodes, P, B and T nodes. P and B nodes are used for body contact
devices. Let us consider the case when TNODEOUT is not set. If user specifies four nodes, this
element is a 4-terminal device, i.e., floating body. If user specifies five nodes, the fifth node
represents the external body contact node (P). There is a body resistance between internal body
node and P node. In these two cases, an internal body node is created but it is not accessible in
the circuit deck. If user specifies six nodes, the fifth node represents the P node and the sixth
node represents the internal body node (B). This configuration is useful for distributed body
resistance simulation.
If TNODEOUT flag is set, the last node is interpreted as the temperature node. In this case,
if user specifies five nodes, it is a floating body case. If user specifies six nodes, it is a body-
contacted case. Finally, if user specifies seven nodes, it is a body-contacted case with an
accessible internal body node. The temperature node is useful for thermal coupling simulation.
If the NODECHK flag is set, different warning messages are displayed and unsupported
  Spice-syntax netlist
(node-order determined
                                           $port_connected(NODE)                                      Warning message
      terminals)
           BSIM-SOI
                           Nodes
          nodes as seen
                          supplied                                     TNODEOUT                          SOIMOD
            from the                                                                         TNODEOUT                   SOIMOD=2
CASE                         on      NODE=P      NODE=B     NODE=T       (instance   SHMOD                =0,1,3
           USER (not                                                                          Messages                   Messages
                          instance                                      parameter)                       Messages
             model)
                            call
           perspective
   1     DGSE                4         F            F              F       0           0       None        None           None
   2     DGSEP               5         T            F              F       0           0       None        None            s1
   3     DGSEPB              6         T            T              F       0           0       None        None            s2
   4     DGSEPBT             7         T            T              T       0           0       None        None            s2
   5     DGSE                4         F            F              F       1           0       None        None           None
   6     DGSET               5         T            F              F       1           0       None        None           None
   7     DGSEPT              6         T            T              F       1           0       None        None            s1
   8     DGSEPBT             7         T            T              T       1           0       None        None            s2
   9     DGSE                4         F            F              F       0           1       None        None           None
  10     DGSEP               5         T            F              F       0           1       None        None            s1
  11     DGSEPB              6         T            T              F       0           1       None        None            s2
  12     DGSEPBT             7         T            T              T       0           1       None        None            s2
  13     DGSE                4         F            F              F       1           1        t1         None           None
  14     DGSET               5         T            F              F       1           1        t2         None           None
  15     DGSEPT              6         T            T              F       1           1        t3         None           None
  16     DGSEPBT             7         T            T              T       1           1       None        None            s2
            Implementation Notes:
            1) These new warning messages are toggled on/off by a new model parameter INSTANCECHK
            (analogous to PARAMCHK).
            2) $port_connected(NODE) only provides information about whether a node is present in the
node list of the instance in the netlist. $port_connected does not provide any information about
3) If more than 4 nodes are specified but the TNODEOUT, SHMOD, and SOIMOD are not set
to use any of the rightmost 5th, 6th, or 7th nodes, these nodes will be ignored and no warning
will be issued.
5) When TNODEOUT=1, the right-most node is always interpreted as the temperature node T.
6) When SOIMOD=0,1,3 the P and B node are treated consistently with the BSIM-SOI self-
heating model.
7) When SOIMOD=2, the P node is grounded, i.e. (V(p) <+ 0) in cases 2,3,4,7,8,10,11,12,15,16.
8) When SOIMOD=2, the B node grounded, i.e. (V(b) <+ 0) in cases 3,4,8,11,12,16.
9) When SHMOD=0 and TNODEOUT=1 there are no self-heating messages because self-
heating is inactive.
10) When SHMOD=1 and TNODEOUT=1 and number of nodes=5, switch SH network to use
11) When SHMOD=1 and TNODEOUT=1 and number of nodes=6, switch SH network to use
12) When SHMOD=1 and TNODEOUT=1 and number of nodes=7, switch SH network to use
         By default, <DEBUG> is set to zero and two internal parameters will be available for
plotting:
         #body          Vb value iterated by SPICE
         #temp          Device temperature with self-heating mode turned on
         If <DEBUG> is set to one or minus one, more internal parameters are available for
plotting. This serves debugging purposes when there is a convergence problem. This can also
help the user to understand the model more. For <DEBUG> set to minus one, there will be
charge calculation even if the user is running DC simulation. Here is the list of internal
parameters:
#Vbs             Real Vbs value used by the IV calculation
#Vgsteff         Effective gate-overdrive voltage
#Vth             Threshold voltage
#Ids             MOS drain current
#Ic              BJT current
#Ibs             Body to source diode current
#Ibd             Body to drain diode current
#Iii             Impact ionization current
#Igidl           GIDL current
#Itun            Tunneling current
#Ibp             Body contact current
#Gds             Output conductance
#Gm               Transconductance
#Gmb              Drain current derivative wrt Vbs
All model parameters additional to BSIM3v3/BSIM4 will be shown with bold cases.
Note: Leffeot, Weffeot, Tempeot and Vddeot are the parameters in EOT extraction and used in
Toxp calculation (i.e., Eq. (10.6)).
B.3. DC Parameters
Symbol     Symbol
used in    used in   Description                                 Unit   Default   Notes (below the
equation   SPICE                                                                          table)
                                                                mWr
Prwb      prwb      Body effect coefficient of Rdsw              1/V       0         -
Prwg      prwg      Gate bias effect coefficient of Rdsw        1/V1/2     0         -
Wr        wr        Width offset from Weff for Rds                -        1         -
                    calculation
Nfactor   nfactor   Subthreshold swing factor                     -        1         -
Wint      wint      Width offset fitting parameter from I-V       m       0.0        -
                    without bias
Lint      lint      Length offset fitting parameter from I-V      m       0.0        -
                    without bias
DWg       dwg       Coefficient of Weff’s gate dependence       m/V       0.0
DWb       dwb       Coefficient of Weff’s substrate body bias   m/V1/2    0.0
                    dependence
DWbc      Dwbc      Width offset for body contact isolation       m       0.0
                    edge
Voff      voff      Offset voltage in the subthreshold region     V      -0.08       -
                    for large W and L
Eta0      eta0      DIBL coefficient in subthreshold region       -      0.08        -
Eta0CV    eta0cv    DIBL coefficient in subthreshold region       -      Eta0        -
                    for CV
Etab      etab      Body-bias coefficient for the                1/V     -0.07       -
                    subthreshold DIBL effect
EtabCV     etabcv   Body-bias coefficient for the                1/V     Etab        -
                    subthreshold DIBL effect for CV
Dsub      dsub      DIBL coefficient exponent                     -      0.56        -
Cit       cit       Interface trap capacitance                  F/m2      0.0        -
Cdsc      cdsc      Drain/Source to channel coupling            F/m2     2.4e-4      -
                    capacitance
Cdscb     cdscb     Body-bias sensitivty of Cdsc                F/m2       0         -
Cdscd     cdscd     Drain-bias sensitivty of Cdsc               F/m2       0         -
                    when gidlMod = 1
Fgidl     fgidl     Vds-dependent parameter for GIDL
                    when gidlMod = 1
Rgisl     rgisl     Vgs-dependent parameter for GISL             -       1.0
                    when gidlMod = 1
Kgisl     kgisl     Vbs-dependent parameter for GISL             V       0.0
                    when gidlMod = 1
Fgisl     fgisl     Vbs-dependent parameter for GISL             V       0.0
                    when gildMod = 1
ndiodes   Ndiode    Diode non-ideality factor for source         -       1.0        -
ndioded   Ndioded   Diode non-ideality factor for drain          -     Default      -
                                                                        to its
                                                                       source
                                                                       value
nrecf0s   Nrecf0    Recombination non-ideality factor at         -       2.0        -
                    forward bias for source
nrecf0d   Nrecf0d   Recombination non-ideality factor at         -     Default      -
                    forward bias for drain                              to its
                                                                       source
                                                                       value
nrecr0s   Nrecr0    Recombination non-ideality factor at         -       10         -
                    reversed bias for source
nrecr0d   Nrecr0d   Recombination non-ideality factor at         -     Default      -
                    reversed bias for drain                             to its
                                                                       source
                                                                       value
isbjt     Isbjt     BJT injection saturation current            A/m2    1e-6        -
Idbjt     Idbjt     BJT injection saturation current            A/m2    1e-6        -
isdif     Isdif     Body to source/drain injection saturation   A/m2    1e-7        -
                    current
                    h shifts
Pditsd    Pditsd    Vds dependence of drain-induced Vth shifts      v-1     0
Fprout    Fprout    Effect of pocket implant on rout degradation   V/m0.5   0.0
Minv      Minv      Vgsteff fitting parameter for moderate                  0.0
                    inversion
                                                                          source
                                                                           value
tt        tt        Diffusion capacitance transit time           second    1e-12         -
                    coefficient
Ndif      Ndif      Power coefficient of channel length            -        -1           -
                    dependency for diffusion capacitance
Ldif0     Ldif0     Channel-length dependency coefficient of       -         1           -
                    diffusion cap.
Vsdfb     vsdfb     Source/drain bottom diffusion capacitance      V       calcu-      nC-3
                    flatband voltage                                       lated
Vsdth     vsdth     Source/drain bottom diffusion capacitance      V       calcu-      nC-4
                    threshold voltage                                      lated
Csdmin    csdmin    Source/drain bottom diffusion minimum          V       calcu-      nC-5
                    capacitance                                            lated
Asd       asd       Source/drain bottom diffusion smoothing        -        0.3          -
                    parameter
Csdesw    csdesw    Source/drain sidewall fringing capacitance    F/m       0.0          -
                    per unit length
CGSl      cgsl      Light doped source-gate region overlap        F/m       0.0          -
                    capacitance
CGDl      cgdl      Light doped drain-gate region overlap         F/m       0.0          -
                    capacitance
CKAPPA    ckappa    Coefficient for lightly doped region          F/m       0.6          -
                    overlap capacitance fringing field
                    capacitance
Cf        cf        Gate to source/drain fringing field           F/m      calcu-      nC-6
                    capacitance                                            lated
CLC       clc       Constant term for the short channel model      m      0.1x10-7       -
CLE       cle       Exponential term for the short channel       none       0.0          -
                    model
                     temperature effect
Ua1        ua1       Temperature coefficient for Ua              m/V         4.31e-9             -
Ub2        ub1       Temperature coefficient for Ub             (m/V)2      -7.61e-18            -
Uc1        uc1       Temperature coefficient for Uc               1/V         -.056         nT-1
At         at        Temperature coefficient for saturation      m/sec        3.3e4              -
                     velocity
Tcijswgs   tcjswg    Temperature coefficient of Cjswgs            1/K           0                -
Tpbswgs    tpbswg    Temperature coefficient of Pbswgs           V/K            0                -
Tcijswgd   tcjswgd   Temperature coefficient of Cjswgd            1/K     Default to its         -
                                                                          source value
Tpbswgd    tpbswgd   Temperature coefficient of Pbswgd           V/K      Default to its         -
                                                                          source value
Cth0       cth0      Normalized thermal capacity                (W*sec)       1e-5               -
                                                                / mºC
Prt        prt       Temperature coefficient for Rdsw           -m            0                -
Rth0       rth0      Normalized thermal resistance              mºC/W           0                -
Ntrecf     Ntrecf    Temperature coefficient for Nrecf             -            0                -
Ntrecr     Ntrecr    Temperature coefficient for Nrecr             -            0                -
Xbjt       xbjt      Power dependence of jbjt on temperature       -            1                -
Xdifs      xdifs     Power dependence of jdifs on temperature      -           Xbjt              -
Xrecs      xrecs     Power dependence of jrecs on temperature      -            1                -
Xtuns      xtuns     Power dependence of jtuns on temperature      -            0                -
Xdifd      xdifd     Power dependence of jdifd on temperature      -           Xbjt              -
Xrecd      xrecd     Power dependence of jrecd on temperature      -            1                -
Xtund      xtund     Power dependence of jtund on temperature      -            0                -
Wth0       Wth0      Minimum width for thermal resistance         m             0                -
                     calculation
Tvbci      tvbci     Temperature coefficient for Vbci              -            0
               Description                                          Default
 Parameter
 EGGBCP2       Bandgap in Agbcp2 region                             1.12
 EGGDEP        Bandgap for gate depletion effect                    1.12
 AGB1          'A' for Igb1 Tunneling current model                 3.7622E-07
 BGB1          'B' for Igb1 Tunneling current model                 -3.1051E+10
 AGB2          'A' for Igb2 Tunneling current model                 4.9758E-07
 BGB2          'B' for Igb2 Tunneling current model                 -2.357E+10
 AGBC2N        NMOS 'A' for tunneling current model                 3.4254E-07
 AGBC2P        PMOS 'A' for tunneling current model                 4.9723E-07
 BGBC2N        NMOS 'B' for tunneling current model                 1.1665E+12
 BGBC2P        PMOS 'B' for tunneling current model                 7.4567E+11
 VTM00         Hard coded 25°C thermal voltage                      0.026
                                    kT     10 20  nsub 
                     Vsdfb           log                0.3
                                     q     ni  ni 
else
                                    kT     10 20 
                     Vsdfb           log         0.3
                                     q     nsub 
else
                             2 si  sd                      si                    Csddep Cbox
      nC-5. X sddep                          , Csddep              , Csd min 
                         q n sub  10     6                X sddep                 Csddep  C box
                             2 ox           4  10 7 
                      CF            ln 1            
                                               Tox 
      nT-1. For mobmod=1 and 2, the unit is m/V2. Default is -5.6E-11. For mobmod=3,
             unit is 1/V and default is -0.056.
If SoiMod=1 (unified model for PD&FD) or SoiMod=2 (ideal FD), the following equations (FD
module) are added on top of BSIMPD.
fdMod = 0
                     CSi                 qN                                         CBOX
       Vbi                       phi  ch  TSi 2  Vnonideal  VDIBL   e               Ves  VFBb 
                 CSi  CBOX              2 Si                                  C Si  C BOX
                          Si                OX              OX
        where CSi              , CBOX            , COX 
                         TSi               TBOX              TOX
                                       Leff                    Leff  
       VDIBL  Dvbd 0  exp   Dvbd 1        2 exp   Dvbd 1         Vbi  2 B 
                                       2l                       l  
                                                                   Leff                 L      
                                e  K 1b  K 2b   exp  Dk 2b          2 exp  Dk 2b eff   
                                                   
                                                                    2l         
                                                                                            l     
                                                                                                   
fdMod = 1
                               Leff                               Leff                
VSCE  DVBD0   exp   DVBD1                    2 exp   DVBD1                        Vds  VSCE 
                               2l                                  l                  
                                                   
                             V gsteff .FD V gsteff ,FD  2 K 1 2 B
        phiON  2 B  Vt ln 1 
                                                                                   ,
                                        MoinFD  K 1  Vt
                                                              2                    
                                                                                  
Here Nch is the channel doping concentration. VFBb is the backgate flatband voltage.
Vth,FD is the threshold voltage at Vbs=Vbs0(phi=2B). Vt is thermal voltage. K1 is the body effect
coefficient.
If SoiMod=1, the lower bound of Vbs (SPICE solution) is set to Vbs0. If SoiMod=2, Vbs is pinned
at Vbs0. Notice that there is no body node and body leakage/charge calculation in SoiMod=2.
The zero field body potential that will determine the transistor threshold voltage, Vbsmos, is then
calculated by
The subsequent clamping of Vbsmos will use the same equation that utilized in BSIMPD.
If SoiMod=3 is specified, BSIMSOI will select the operation mode for the user based on the
estimated value of Vbs0 at phi=2B (bias independent), Vbs0t:
       If Vbs0t > Vbs0fd, BSIMSOI will be in the ideal FD mode (SoiMod=2).
       If Vbs0t < Vbs0pd, BSIMSOI will be in the BSIMPD mode (SoiMod=0).
       Otherwise, BSIMSOI will be operated under SoiMod=1.
Notice that both Vbs0fd and Vbs0pd are model parameters.
Body Voltages
Vbsh is equal to the Vbs bounded between (Vbsc,  s1 ). Vbsh is used in Vth and Abulk calculation
Threshold Voltage
                                                                   LPEB
Vth  Vtho  ( K1ox sqrtPhisExt  K1eff  s ) 1                          K 2oxVbseff
                                                                    Leff
               LPE 0                                   T
 K1ox ( 1           1)  s  ( K 3  K 3bVbseff ) ' ox     s
                Leff                                Weff  Wo
                           Weff' Leff                            Weff' Leff
 DVT 0 w (exp( DVT 1w                 )  2 exp( DVT 1w                    ))(Vbi   s )
                                2ltw                                 ltw
                         Leff                          Leff
 DVT 0 (exp( DVT 1            )  2 exp( DVT 1             ))(Vbi   s )
                         2lt                            lt
                 Leff                         Leff
(exp( Dsub            )  2 exp( Dsub             ))( Etao  EtabVbseff )Vds
                 2lto                         lto
                        Leff                      
nvt  ln                                         
           Leff  DVTP 0  (1  e   DVTP1V
                                                ) 
          
                                             DS
  DVTP 2
              tanh( DVTP 4  Vds )
  Leff DVTP 3
Note: The last term (DVTP2, DVTP3 and DVTP4) introduces the flexibility to capture DIBL
variation in longer channel. Considering backward compatibility, the old term (DVTP1 and
DVTP2) is kept.
lt   si X dep / Cox (1  DVT 2Vbseff )
                                                             , s  2
                                                                                  1
sqrtPhisExt   s  Vbseff  s Vbsh  Vbseff
                                                                                s   s0
                 K        
K1eff  K1 1  ' 1w1 
             Weff  K1w 2 
                TOX
K1ox  K1eff
               TOXM
                TOX
K 2 ox  K 2
               TOXM
             2 si (  s  Vbseff )                                 2 si  s
X dep                                                  X dep 0 
                       qN ch                                         qN ch
                N ch N DS
Vbi  vt ln(              )
                   ni 2
                                          2
           1                 qN gate X        poly
V poly      X poly E poly 
           2                      2 si
              2 ox
a
      2q si N gateT 2 ox
                      arctan(MINV)
m*  0.5 
                            π
                                                                                   Leff                    Leff 
                                    (Cdsc  Cdscd Vds  Cdscb Vbseff )exp(  DVT 1      )  2 exp(  DVT 1     )
                    si / X dep                                                    2 lt                     lt  Cit
n  1  N factor                                                                                                  
                       Cox                                               Cox                                         Cox
                                1  Keta  Vbsh                                                                                                    
Abulk 0  Abulk Vgsteff  0
                                                                              o
                                 eff 
                                                                    Vgsteff  2Vth                 Vgsteff  2Vth
                                          1  (Ua  Uc Vbseff )(                        )  Ub (                          )2
                                                                            Tox                              Tox
For Mobmod=2
                                                                      o
                                      eff 
                                                                        Vgsteff               Vgsteff
                                               1  (Ua  Uc Vbseff )(             )  Ub (              )2
                                                                           Tox                 Tox
For Mobmod=3
                                                                      0
                           eff 
                                                Vgstef  2Vth              Vgsteff  2Vth
                                    1  [Ua (                   )  Ub (                      )2 ](1  Uc Vbseff )
                                                    Tox                           Tox
For Mobmod=4
                                                                            U0
            eff 
                                                           C  VTH 0  VFB   s  
                                                                                                        EU
                                                  V
                     1  UA  UC  Vbseff        gsteff 0 TOXE                                                                  UD
                                                                                                                                                UCS
                                                                                                               1  Vgsteff Vgsteff ,Vth 
           Vgsteff ,Vth  Vgsteff Vgse  Vth ,Vds  Vbs  0 
mtrlMod = 1
               For MobMod = 1
                                 o
    eff 
              1  (U a  U cVbseff ) Eeff  U b Eeff 2
              For MobMod = 2
                                              o
    eff 
                                        Vgsteff  U d              Vgsteff  U d
              1  (U a  U cVbseff )(                   )  Ub (                   )2
                                            Tox                        Tox
   U d  2  BSIM 4type  ( PHIG  EASUB  Eg / 2  0.45)
For MobMod = 3
                              0
eff 
          1  [U a Eeff  U b Eeff 2 ](1  U cVbseff )
For MobMod = 4
                                                                   U0
eff 
                                              C  VTH 0  VFB   s  
                                                                                        EU
                                     V
          1  UA  UC  Vbseff      gsteff 0 TOXE                                                          UD
                                                                                                                               UCS
                                                                                               1  Vgsteff Vgsteff ,Vth 
Vgsteff ,Vth  Vgsteff Vgse  Vth ,Vds  Vbs  0 
           b  b2  4ac
Vdsat 
                2a
                                      1
a  Abulk 2 Weff  sat Cox Rds  (         1) Abulk
                                      
b   (Vgsteff  2 t )(  1)  Abulk Esat Leff  3 Abulk (Vgsteff  2 t )Weff  sat Cox Rds 
                          2
                                                                                               
  AV
     1 gsteff  A2
         2 sat
Esat 
          eff
Vdseff
Vdseff  Vdsat 
                        1
                        2   
                          Vdsat  Vds    (Vdsat  Vds   ) 2  4Vdsat                   
Drain current expression
                     1         I ds 0 (Vdseff )        Vds  Vdseff
I ds, MOSFET                                     (1               )
                    N seg      Rds Idso (Vdseff )          VA
                            1
                                       Vdseff
                                          Weff
                           eff Cox
                                           Leff
                                           Vdseff       
          Vgsteff 1  Abulk                            Vdseff
Idso 
                                     
                                     2 Vgsteff     2vt   
                                      Vdseff
                                1
                                     Esat Leff
                               PvagV gsteff               1       1
           V A  V Asat  1                         (              ) 1
                                Esat Leff              V ACLM V ADIBLC
                                            Leff                           Leff
 rout  PDIBLC1[exp(  DROUT                         2 exp(  DROUT              )]  PDIBLC 2
                                            2lt 0                           lt 0
                                                                    Abulk Vdsat
          Esat Leff  Vdsat  2 Rds sat Cox Weff Vgsteff [1                       ]
                                                                 2(Vgsteff  2 t )
VAsat 
                             2 /   1  Rds sat Cox Weff Abulk
                     siTox TSi
          litl 
                         ox
Drain/Source Resistance
                                                      *                                                         +
                                                                                            (               )
                   ( )
                                                          (                )
                                                      *                                                             +
                                                                                            (               )
                   ( )
                                                          (                )
                                  k BT  N gate 
          Where, V fbsd              ln  20  for NGATE larger than 0, otherwise, V fbsd  0 .
                                    q     10 
• rdsMod = 2 (Bias Dependent Internal Resistance, Rds(V))
                                                                                (√                  √   )
            ( )
                                                                   (               )
Where, The resistance Rs,geo and Rd,geo are simply calculated as the sheet resistance (RSH) times
the number of squares (NRS, NRD):
Rs,geo = NRS*RSH
Rd,geo = NRD*RSH
                                               T         L 
      Vdsatii  VgsStep  Vdsatii 0 1  Tii        1   ii 
                                              Tnom       Leff 
                 E satii Leff                  1                    S ii 0V gst    
      VgsStep                                             S ii 2                
                1 E L                   1  S V                    1 S V
                      satii eff               ii 1 gsteff                 iid ds    
Gate-Induced-Drain-Leakage (GIDL)
       gidlMod = 0
                                      Vds  Vgse  EGIDL  V fbsd            3  Toxe  BGIDL     Vdb3
      I GIDL  AGIDL Wdiod  Nf                                    exp                     
                                                 3  Toxe                  Vds  Vgse  EGIDL  CGIDL  Vdb3
                                                                                              
        gidlMod = 1
                                     Vds  RGIDL Vgse  EGIDL  V fbsd              3  Toxe  BGIDL          KGIDL 
      I gidl  AGIDL Wdiod  Nf                                            exp                        exp 
                                                    3  Toxe                       Vds  Vgse  EGIDL                      
                                                                                                               Vbd  FGIDL 
                         J gb   A
                                   V gbVaux  Toxref
                                            
                                                              
                                                              
                                                                   N tox
                                                                           exp
                                                                                                       
                                                                                B α gb1  β gb1 Vox Tox   
                                                                                                            
                                      Tox2  Toxqm           
                                                              
                                                                              
                                                                                    1  Vox Vgb1           
                                                                                                            
                                               Vox  φ g                     
                        Vaux  VEVB ln 1  exp                               
                                               VEVB                          
                                                                             
                                   q3
                         A
                                 8h b
                                8 2mox  b3 2
                         B
                                   3hq
                          b  4.2eV
                         mox  0.3m0
In accumulation,
                         J gb   A
                                   V gbVaux  Toxref
                                            
                                                       
                                                       
                                                           N tox
                                                                   exp
                                                                                             
                                                                        B α gb2  β gb2 Vox Tox   
                                                                                                    
                                      Tox2  Toxqm    
                                                       
                                                                      
                                                                            1  Vox Vgb2           
                                                                                                    
                                                  V gb  V fb  
                        Vaux  VECBVt ln 1  exp            
                                        
                                                     VECB  
                                  q3
                         A
                                8h b
                                8 2mox  b3 2
                         B
                                     3hq
                         b  3.1eV
                         mox  0.4m0
                     Vbp
       I bp 
                Rbp  Rbodyext
                                            Leff  
                                                    2
Body-to-Source/drain diffusion
                                                                 Vbs         
                                   I bs1  WdiosTsi jdifs  exp              1
                                                                                    
                                                                 ndiodeVt     
                                                                   Vbd          
                                   I bd 1  Wdiod Tsi jdifd  exp               1
                                                                                       
                                                                   ndiodedVt     
                                       Vbs                               Vrec0  
      I bs 2  WdiosTsi jrecs  exp                 exp Vsb                        
                                                         
                                    0.026nrecf           0 . 026nrecr Vrec 0  V sb   
                                         Vbd                 Vdb          Vrec0 d  
      I bd 2  Wdiod Tsi jrecd  exp                 exp
                                                            0.026n                      
                                      0. 026n                            V         V     
                                             recfd                recrd  rec 0 d    db
                                         Vsb          Vtun 0  
      I bs 4  WdiosTsi jtuns  1  exp                        
                                                                     
                                         0.026ntun Vtun 0  Vsb  
                                             Vdb        Vtun 0d  
      I bd 4  Wdiod Tsi jtund  1  exp                          
                                                                        
                                          0.026ntund Vtun 0d  Vdb  
                                Vbs                
                         
      I bs 3  1   bjt I en exp                  1
                                                            1
                                ndiodeVt             Ehli  1
                                Vbd                 
                         
      I bd 3  1   bjt I en exp                   1
                                                             1
                                ndiodedVt             Ehlid  1
                                                            N bjt
                  '
                Weff                      1     1  
      I ens          Tsi jsbjt  Lbjt 0          
                N seg                    Leff Ln  
                                                            N bjt
                   '
                 Weff                      1         1  
      I end           Tsi jdbjt  Lbjt 0              
                 N seg                    Leff     L n  
                            Vbs  
      E hlis  Ahli _ eff exp                  1
                            diode t  
                                    n        V
                             Vbd  
      E hlid  Ahli _ eff exp                    1
                             ndiodedVt  
                                   E g 300K                    T   
      Ahlis _ eff  Ahli exp                          X bjt  1       
                                  ndiodeVt                    Tnom     
                               E g 300K              T               
      Ahlid _ eff  Ahlid exp               X bjt  1                   
                              ndiodedVt             Tnom                 
                                                   V           V           1
                              I c   bjt I en exp  bs   exp  bd  
                                                   ndiodesVt   ndiodedVt   E2 nd
                                        Eely  Eely 2  4 Ehli
                              E2 nd 
                                                  2
                                            Vbs  Vbd
                              Eely    1
                                          VAbjt  Aely Leff
                              Ehli  Ehlis  Ehlid
Temperature effects
                                                T te
                     o( T )   o( Tnom ) (        )    sat ( T )   sat ( Tnom )  AT (T / Tnom  1)
                                               Tnom   ,
                                                                                  T
                                         Rdsw ( T )  Rdsw ( Tnom )  Prt (            1)
                                                                                 Tnom
U a ( T )  U a ( Tnom )  U a1 (T / Tnom  1)
                                                    Rth0
                                                                                     '
                                                                                    Weff  Wth0
                                Rth                              , C th  C th0
                                        W   '
                                             eff           
                                                    Wth0 N seg                         N seg
                          E g (300K )             T             
       jsbjt  isbjt exp               X bjt  1                 
                         ndiodeVt              Tnom               
                           Eg (300 K )           T             
       jdbjt  idbjt exp                X bjt 1                
                          ndiodedVt           Tnom              
                           E g (300 K )             T             
       jsdif  i sdif exp                X dif  1                 
                          ndiodeVt               Tnom               
                          E g (300 K )              T                  
       jddif  iddif exp                X difd  1                      
                         ndiodedVt               Tnom                    
                          E g (300 K )             T              
       jsrec  isrec exp                X rec  1                  
                         nrecf 0Vt             Tnom                 
                            E g (300K )              T   
         jdrec  idrec exp               X recd  1       
                           nrecf 0dVt            Tnom      
                                    T        
         jstun  i stun exp X tun        1 
                                    Tnom     
                                    T        
         jdtun  idtun exp X tund        1 
                                    Tnom     
                                      T          
        nrecfs  nrecf 0 1  ntrecf          1 
                                      Tnom       
                                        T          
        nrecfd  nrecf 0d 1  ntrecf          1 
                                        Tnom       
                                     T          
        nrecrs  nrecr0 1  ntrecr          1 
                                     Tnom       
                                        T          
        nrecrd  nrecr0d 1  ntrecr           1 
                                        Tnom       
Dimension Dependence
                    Wlc   W         W
Weff  DWC         Wln
                          Wwcwn  Wln wlcWwn
                    L     W       L W
                  Llc    L        L
Leff  DLC       Lln
                        wcLwn
                                Lln wlcLwn
                  L     W       L W
Lactive  Ldrawn  2Leff
LactiveB  Lactive  DLCB
LactiveBG  LactiveB  2Lbg
Charge Conservation
QBf  Qacc  Qsub 0  Qsubs
         
Qg   Qinv  QBf      
Qb  QBf  Qe  Q js  Q jd
Qs  Qinv , s  Q js
Qd  Qinv ,d  Q jd
Qg  Qe  Qb  Qs  Qd  0
Intrinsic Charges
         (1) capMod = 2
Front Gate Body Charge
Accumulation Charge
                                                                      
                                         V fb  Vgb   
                                                                2
VFBeff  V fb  0.5 V fb  Vgb                                  2
                                                                      
                                              W L                     
                               Qacc   Fbody  active activeB  Agbcp  Cox (VFBeff  Vfb )
                                                   N seg              
                 vgstcvMod = 0 and 1
                                                              V gs  Vth        delvt  
                                  V gsteffCV  nvt ln 1  exp             exp       
                                                                  nvt            nvt  
vgstcvMod = 2
                   Wactive LactiveB                                                                          
                                                                1  1  4(Vgs  VFBeff  VgsteffCV  Vbseff ) 
                                                       2
                                                 K1eff
Qsub0     Fbody                          
                                      Agbcp Cox
                       N seg                    2                                          2
                                                                                                                
                                                                                     K1eff                   
Drain Induced Depletion Charge
                                                                  CLC  CLE 
          VdsatCV  VgsteffCV / AbulkCV , AbulkCV      Abulk 0 1           
                                                                  LactiveB  
                           1
          VdsCV  VdsatCV  (VdsatCV  Vds    (VdsatCV  Vds   )2  4 VdsatCV )
                           2
              W L                                               V                           2           
Qsubs  Fbody  active activeB  Agbcp  K1eff Cox  AbulkCV  1  dsCV 
                                                                                     AbulkCV VdsCV
                                                                                                           
                   Nseg                                          2             
                                                                           12 VgsteffCV  AbulkCV VdsCV 2     
Inversion Charge
                                                       
Vcveff  Vdsat ,CV  0.5 V4  V42  4 4 Vdsat ,CV whereV4  Vdsat ,CV  Vds   4 ;  4  0.02
                                                                                                           
                                                                                                           
        W L                                          AbulkCV        
                                                                                            2
                                                                                     AbulkCV Vcveff 2
                                                                                                            
Qinv   active active       Agbcp  Cox  VgsteffCV          Vcveff  
            Nseg                                       2                              A        2
                                                                                                          
                                                                           12 VgsteffCV  bulkCV Vcveff  
                                                                                             2          
               Wactive Lactive          
                               Agbcp  Cox
                   N seg                       V            5
                                                                                                                              1
                                                                                                                                                      
                                                                                                                          2                            3
Qinv,d                                       2  gsteffCV
                                                            3
                                                               VgsteffCV 2 AbulkCV Vcveff  Vgsteff AbulkCV Vcveff                AbulkCV Vcveff
                             A                              3                                                                  5
             2 VgsteffCV  bulkCV Vcvefff 
                               2           
                                                                                                          
                                                                                                          
Qinv ,d    
              Wactive Lactive  Agbcp
                                      Cox  VgsteffCV 3 AbulkCV Vcveff
                                                                      
                                                                                AbulkCV Vcveff 
                                                                                                 2
                                                                                                           
                       N seg               2                4                         AbulkCV          
                                                                        8VgsteffCV             Vcveff  
                                                                                         2             
capMod = 3 only supports zero-bias flat band voltage, which is calculated from bias-independent
threshold voltage. This is different from capMod = 2. For the finite thickness ( X DC ) formulation,
refer to Chapter 4 of BSIM3v3.2 Users’s Manual.
                                  W L                     
                   Qacc   Fbody  active activeB  Agbcp Coxeff Vgbacc
                                      N seg               
                                                          
                                  
                   Vgbacc  0.5 V0  V02  4V fb         
                   V0  V fb  Vbseff  Vgs  
                               Cox Ccen
                   Coxeff 
                              Cox  Ccen
                   Ccen   Si X DC
                   Wactive LactiveB                                                                          
                                                                1  1  4(Vgs  VFBeff  VgsteffCV  Vbseff ) 
                                                          2
                                                    K1eff
Qsub0     Fbody                          
                                      Agbcp Coxeff
                       N seg                       2                                       2
                                                                                                                
                                                                                     K1eff                   
Drain Induced Depletion Charge
          VdsatCV  VgsteffCV    / AbulkCV
                                                      
                                   VgsteffCV VgstefCV  2 K1eff 2 B
             s  2 B  vt ln 1 
                                                                                  
                                             moinK1eff vt2                       
                           1
          VdsCV  VdsatCV  (VdsatCV  Vds    (VdsatCV  Vds   )2  4 VdsatCV )
                           2
              W L                                                 V                              2               
Qsubs  Fbody  active activeB  Agbcp  K1eff Coxeff  AbulkCV  1 dsCV 
                                                                                          AbulkCV VdsCV
                                                                                                                    
              
                  N seg               
                                                                    2     12VgsteffCV     AbulkCV VdsCV 2 
Inversion Charge
Vcveff  Vdsat ,CV  0.5V4  V42  4 4Vdsat ,CV  whereV 4  Vdsat ,CV  Vds   4 ;  4  0.02
                                                         
                                                                                                                                  
                                                                                                                                  
          WactiveLactive                                      A                               A
                                                                                                           2
                                                                                                            V
                                                                                                                    2              
Qinv                     Agbcp C oxeff  V gsteffCV     bulkCV Vcveff                                                
                                                                                                    bulkCV    cveff
                N seg                                            2                                                2
                                                                                                                                 
                                                                                    12V gsteffCV    
                                                                                                               A
                                                                                                                          Vcveff  
                                                                                                                bulkCV
                                                                                                                  2            
                                                                                                                               
                  Wactive Lactive         
                                   Agbcp C oxef
                  N                       
Qinv ,d                 seg                        
                                                     2 
                                                         V gsteffCV    3  5 V gsteffCV    2 AbulkCV Vcveff   V gstefCVf    AbulkCV Vcveff 2  1 AbulkCV Vcveff 3 
                                   A                                         3                                                                                  5                     
              2V gsteffCV     bulkCV Vcvefff 
                                      2           
                                         Coxeff                                                                                
                                                   V                 A      V                      A      V
Qinv , s                                                                         
                                                     gsteffCV          bulkCV cveff                  bulkCV cveff
                         N seg                             2               4                                AbulkCV        
                                                                                    24V gsteffCV               Vcveff  
                                                                                                                 2         
                                                                                                                            
                                                                                                                            
Qinv ,d     
               Wactive Lactive  Agbcp
                                       Coxeff  V gsteffCV    3 AbulkCV Vcveff
                                                                                 
                                                                                                 AbulkCV Vcveff 
                                                                                                                  2
                                                                                                                             
                        N seg                           2              4                                  AbulkCV        
                                                                                   8V gsteffCV                Vcveff  
                                                                                                               2         
Overlap Capacitance
Source Overlap Charge
                                                                                                       1
                                                                                                                V                    4 
                                                                                                                                    2
                                                                                    Vgs _ overlap       Vgs           
                                                                                                       2                                     
                                                                                                                      gs
                                                                                                      
        Qoverlap, s                                                CKAPPA         4V gs _ overlap   
                       CGS 0  V gs  CGS1V gs  V gs _ overlap            1 1
        WdiosCV                                                       2              CKAPPA           
                                           
                                                                                                     
                                                                                                        
                                                      1                                               
                                                                          Vgd   
                                                                                              2
                                       Vgd _ overlap   Vgd                                    4 
                                                      2                                               
                                          
                                                                CKAPPA        4Vgd _ overlap  
                                                                                                
        Qoverlap,d
                         CGD0 Vgd  CGD1Vgd  Vgd _ overlap           1 1                  
        WdiodCV                                                   2            CKAPPA  
                                                                                                
                                                                   
                                                 Qoverlap, g   Qoverlap,s  Qoverlap,d      
else
else
where
                                Pbswgs                                                  
                                                                            1 M jswgs
                           T                                               
Qbsdep     WdioCV C jswgs si7          1  1  Vbs                                  
                          10 1  M jswgs   Pbswgs                                     
                                                                                         
                                 Pbswgd                                                     
                                                                                 1 M jswgd
                            T                                                   
Qbddep      WdioCV C jswgd si7          1  1  Vbd                                     
                           10 1  M jswgd   Pbswgd                                        
                                                                                             
                        
C jswgs  C jswgs 0 1  t cjswgs T  Tnom           
C jswgd  C jswgd 0      1  tT  Tnom
                                  cjswgd              
Pbswgs  Pbswgs 0  t pbswgs T  Tnom 
Pbswgd  Pbswgd 0  t pbswgd T  Tnom 
               Weff '                             1         
                                                                N dif
                                                                        V  
                                                          1                             1
Qbsdif            Tsi J sbjt 1  Ldif 0  Lbj 0          exp  bs   1
                                                  Leff Ln    
             N seg
                                                                 ndiosVt   Ehlis  1
             Weff '                               1         
                                                                 N dif
                                                                        V  
                                                           1                             1
Qbddif            Tsi J dbjt 1  Ldif 0  Lbj 0          exp  bd   1
                                                           
             N seg
                                                  Leff Ln      ndiodVt   Ehlid  1
Extrinsic Capacitance
Bottom S/D to Substrate Capacitance (per unit area)
                               Cbox                                if                        Vs / d ,e  Vsdfb
                                                           2
                                       Vs / d ,e  Vsdfb 
        
         box A
           C    
                   1
                       C box  C    
                                  min 
                                                          
                                                          
                                                                  elseif                                   
                                                                            Vs / d ,e  Vsdfb  Asd Vsdth  Vsdfb   
Cesb
        
       
                    sd                 Vsdth  Vsdfb 
                                                              2
                                       V          V 
        Cmin 
                   1
                         Cbox  Cmin  s / d ,e sdth         elseif                      Vs / d ,e  Vsdth
               1  Asd                  Vsdth  Vsdfb 
                             Cmin                                else
       mtrlMod = 0
                     Coxp  Ccen
          Coxeff 
                     Coxp  Ccen
Ccen   si / X DC
                 1                    NDEP 
                                                  0.25
                                                          Vgse  Vbseff  VFBeff      
           X DC  Ldebye exp  ACDE        16 
                                                                                     
                 3                   2 10                   TOXP                 
       For numerical stability,
        X DC  X max 
                           1
                           2
                             
                             X 0  X 02  4 x X max       
        X 0  X max  X DC   x
   (ii) XDC of inversion charge
                                 ADOS 1.9 109 m
       X DC                                                   0.7 BDOS
                    V        4 VTH 0  VFB   s  
                1   gsteff                          
                                  2TOXP              
   (iii) Body charge thickness in inversion
                                             VgsteffCV  (VgsteffCV  2K1ox 2 B 
            s  2 B   t ln 1                                             
                                                        MOIN  K1ox 2 t         
                                                                                 
mtrlMod = 1
                                     3.9
             TOXP  EOT                    X DC V VDDEOT ,V V 0
                                   EPSRSUB         gs         ds bs
parameters at subthreshold. (A3) is used to extract saturation velocity, body charge effect, output
resistance, body contact resistance and self-heating parameters.
   Measurement set C is used to extract impact ionization current parameters. For each body-
contacted device :
       (C1)    Ib vs. Vgs @ different Vds, Vbs=0V, Ves=0V.
       (C2)    Ib vs. Vds @ different Vgs, Vbs=0V, Ves=0V.
   Measurement set D is used to extract MOS temperature dependent parameter. For a long
channel body-contacted device:
       (D1)    Ids vs. Vgs @ small Vds, Vbs=0V, Ves=0V, repeat with several temperatures.
       (D2)    Ids vs. Vds @ different Vgs, Vbs=0V, Ves=0V, repeat with several temperatures.
   Notice that the self-heating parameters have to be extracted from set A.
   Measurement set E is used to extract diode parameters. For a long channel body-contacted
device or gated diode :
       (E1)    Idiode vs. Vbs @ Vgs=-1V, Ves=0V, repeat with several temperature
   Measurement set F is used to extract BJT parameters. For each body-contacted device:
       (F1)    Ids vs. Ib @ Vgs=-1V, Ves=0V, Vds=1V.
   Measurement set G is used to verify the floating body device data. For each floating-body
device :
       (G1)    Ids vs. Vgs @ small Vds.
       (G2)    Ids vs. Vgs @ Vds=Vdd.
       (G3)    Ids vs. Vds @ different Vgs.
Below is the information on parameter binning regarding which model parameters can or cannot
be binned. All those parameters which can be binned follow this implementation:
                                               P      P         PP
                                    P  P0  L  W 
                                              Leff Weff Leff  Weff
For example, for the parameter k1: P0 = k1, PL = lk1, PW = wk1, PP = pk1. binUnit is a bining unit
selector. If binUnit = 1, the units of Leff and Weff used in the binning equation above have the units
of microns; otherwise in meters.
For example, for a device with Leff = 0.5m and Weff = 10m. If binUnit = 1, the parameter values
for vsat are 1e5, 1e4, 2e4, and 3e4 for vsat, lvsat, wvsat, and pvsat, respectively. Therefore, the
effective value of vsat for this device is
                      vsat = 1e5 + 1e4/0.5 + 2e4/10 + 3e4/(0.5*10) = 1.28e5
To get the same effective value of vsat for binUnit = 0, the values of vsat, lvsat, wvsat, and pvsat
would be 1e5, 1e-2, 2e-2, 3e-8, respectively. Thus,
             vsat = 1e5 + 1e-2/0.5e-6 + 2e-2/10e-6 + 3e-8/(0.5e-6 * 10e-6) = 1.28e5
Model parameters that have been binned in B4SOI are listed as follows:
     E.1. DC Parameters
Symbol     Symbol
used in    used in                                   Description
equation SPICE
Vth0       vth0      Threshold voltage @Vbs=0 for long and wide device
K1         k1        First order body effect coefficient
K1w1       k1w1      First body effect width dependent parameter
K1w2       k1w2      Second body effect width dependent parameter
K2         k2        Second order body effect coefficient
K3         k3        Narrow width coefficient
K3b        k3b       Body effect coefficient of k3
Kb1        Kb1       Backgate body charge coefficient
W0         w0        Narrow width parameter
NLX        nlx       Lateral non-uniform doping parameter
Dvt0       Dvt0      first coefficient of short-channel effect on Vth
Dvt1       dvt1      Second coefficient of short-channel effect on Vth
Dvt2       dvt2      Body-bias coefficient of short-channel effect on Vth
Dvt0w      dvt0w     first coefficient of narrow width effect on Vth for small channel length
Dvt1w      dvt1w     Second coefficient of narrow width effect on Vth for small channel
                     length
Dvt2w      dvt2w     Body-bias coefficient of narrow width effect on Vth for small channel
                     length
0         u0        Mobility at Temp = Tnom
Ua         ua        First-order mobility degradation coefficient
Ub         ub        Second-order mobility degradation coefficient
Uc         uc        Body-effect of mobility degradation coefficient
vsat       vsat      Saturation velocity at Temp=Tnom
A0         a0        Bulk charge effect coefficient for channel length
                                            References
[1]   Y. Cheng, M. C. Jeng, Z. H. Liu, J. Huang M. Chan, P. K. Ko, and C. Hu, “A Physical            and
      Scalable I-V Model in BSIM3v3 for Analog/Digital Circuit Simulation”, IEEE Trans. On Elec.
      Dev., vol. 42, p. 2, Feb 1997.
[5]   D. Suh, J. G. Fossum, “A physical charge-based model for non-fully depleted SOI MOSFET’s and
      its use in assessing floating-body effects in SOI CMOS circuits”, IEEE Tran. on Electron Devices,
      vol. 42, no. 4, pp. 728-37, April 1995.
[7]   D. Sinitsky, S. Tang, A. Jangity, F. Assaderaghi, G. Shahidi, C. Hu, “Simulation of SOI Devices
      and Circuits using BSIM3SOI”, IEEE Electron Device Letters, vol. 19, no. 9, pp. 323-325,
      September 1998.
[8] G. S. Gildenblat, VLSI Electronics: Microstructure Science, p. 11, vol. 18, 1989.
[10] D. Sinitsky, S. Fung, S. Tang, P. Su, M. Chan, P. Ko, C. Hu, “A Dynamic Depletion SOI MOSFET
      Model for SPICE”, in Dig. Tech. Papers, Symp. VLSI Technology, 1998.
[11] D. Sinitsky, R. Tu, C. Liang, M. Chan, J. Bokor and C. Hu, “AC output conductance of SOI
      MOSFETs and impact on analog applications”, IEEE Electron Device Letters, vol.18, no.2, pp. 36-
      38, Feb 1997.
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