monte carlo simulation hspice delvt0
I think I understand what you mean for the command lines in Monte Carlo.
Maybe you can check hpsice 2001 manual, chapter 13- page11 and 12. Then you might understand why I was using the command that way.
.LIB TT
$TYPICAL P-CHANNEL AND N-CHANNEL CMOS LIBRARY DATE:3/4/91
$ PROCESS: 1.0U CMOS, FAB22, STATISTICS COLLECTED 3/90-2/91
$ following distributions are 3 sigma ABSOLUTE GAUSSIAN
.PARAM
$ polysilicon Critical Dimensions
+ polycd=agauss(0,0.06u,1) xl=’polycd-sigma*0.06u’
$ Active layer Critical Dimensions
+ nactcd=agauss(0,0.3u,1) xwn=’nactcd+sigma*0.3u’
+ pactcd=agauss(0,0.3u,1) xwp=’pactcd+sigma*0.3u’
Slow Corner Skew Parameters
Fast Corner Skew Parameters FF
Typical Corner Skew Parameters + Gaussian TT
SS
EE Extracted Skew Parameters
pop.
IDS
Performing Worst Case Analysis Statistical Analysis and Optimization
13-12 Star-Hspice Manual, Release 2001.4
$ Gate Oxide Critical Dimensions (200 angstrom +/- 10a at 1
$ sigma)
+ toxcd=agauss(200,10,1) tox=’toxcd-sigma*10’
$ Threshold voltage variation
+ vtoncd=agauss(0,0.05v,1) delvton=’vtoncd-sigma*0.05’
+ vtopcd=agauss(0,0.05v,1) delvtop=’vtopcd+sigma*0.05’
above lines were from hspice manual. I know I can define the delvt0 in .model for specified mos transistors. But don't you think it's such an inconvenient way, since you must have so many different transistors using the same model. And this means you have to add the models again and again for different transistors if you wnat to specify the local mismatch for them. I was wondering that if I can alter the model parameter, for example - the delvt0, by not modifying the original model. Since this model would also be used for other transistors.