Model

Model syntax

The following syntax specifies BSIM4 model:

model ModelName bsim4 <parameter=value> ...

The third parameter, “bsim4”, is the master to indicate this model card is a BSIM4 model card.

Sample Model Statement

model pchmod bsim4 type=p mobmod=0 capmod=2 version=4.21 toxe=3e-9 cdsc=2.58e-4 cdscb=0 cdscd=6.1e-8 cit=0 nfactor=1.1 xj=9e-8 vfb=0.76vsat=9.2e4 at=3.3e4 a0=1.1 ags=1.0e-20 a1=0 ngate=9e19 vth0=-0.42 a2=1 delta=0.014 pvag=1e-20 pclm=6.28e-4 pdits=0.2 pditsl=2.3e6pditsd=0.23 fprout=0.2 pdiblcb=3.4e-8 pdiblc1=0.81 drout=0.56pdiblc2=9.84e-6 pscbe1=8.14e8 pscbe2=9.58e-07 lint=5e-9 wint=5e-9 dmcg=5e-6 dmci=5e-6 dmdg=5e-6 dmcgt=6e-7 dwj=4.5e-8 rsh=6cgso=7.43e-10 cgdo=7.43e-10 cgbo=2.56e-11 cgsl=1e-14 cgdl=1e-14ckappas=0.5 ckappad=0.5 noff=0.9 voffcv=0.02 acde=1 moin=15 xpart=0kt1l=0 kt2=2.2e-2 lpe0=5.75e-8 lpeb=2.3e-10 dvt0=2.89 dvt1=0.53dvt2=-3.2e-2 dvt0w=0 dvt1w=0 dvt2w=0 dvtp0=7.32e-7 dvtp1=0.12dsub=0.058 eta0=0.001 u0=4.19e-2 ua=8.7e-16 ub=3.06e-18 k1=0.33uc=4.6e-13 ute=-1.5 ua1=4.31e-9 ub1=7.61e-18 uc1=-5.6e-11 k2=-1.87e-2 rdsw=369.4 rdw=184.7 rsw=184.7 prwg=3.22e-8 prwb=6.8e-11 wr=1 rdswmin=0 rdwmin=0 rswmin=0 prt=0 b0=-1e-20 k3=80 k3b=0 w0=2.5e-6b1=0 keta=-0.047 alpha0=7.4e-2 alpha1=0.005 beta0=30

Auto Model Selection

BSIM4 supports dependent model parameters; users can tune these parameters to make a single model card to fit all sizes of devices. But with device geometry shrinks, device needs all kinds of optimization, there are complicated physical effects. It is difficult to use a single model card to fit all devices. An alternative approach is binning option that uses interpolation to calculate model parameters covered by inside that bin. The binning equation is given by

P = P0 + Pl / Leff + Pw / Weff + Pp / (Leff * Weff)

The names of P_l, P_w, and P_p are identical to that of P₀ but with a prefix of l, w, and p, respectively.

Bin selection criteria are as follows:

lmin <= inst_length < lmax  and   wmin <= inst_width  < wmax