so from ptm i am using level 54 model bsim4 version.but are they developed by berkeley guys?? they are preductive assumptions for future technology,i mean not like researched by berkeley guys and official ones.
cyrax, you have to differentiate between the BSIM
models per se, which are developed by the Berkeley guys, and which describe the methods and equations how the analysis tools (simulators) have to calculate the device properties from the parameters which are given in the model files - and the BSIM model
parameter files themselves, whose parameters could either be estimated - as in the PTM models - or be extracted from silicon (by statistical measurement methods) and calculated with the help of special
extraction software and rather complex computation effort, by the chips' producing (silicon) fabs and foundries.
I.e. a BSIM model without parameters can't be helpful for device analysis, you need a BSIM
parameter file for that. If the Berkeley guys offer such a BSIM
parameter file, these parameters may - or may not - stem from true silicon extracted measurements - and you wouldn't know from which (company's) process; they ain't necessarily better than the estimated parameter values from (e.g.) PTM.
BSIM model parameter files from both Berkeley or PTM are good enough for academic/educational purpose usage; if you need to design for a special process from a real semiconductor fab/foundry, you will need their individual PDK and simulator model files, which contain the actual parameters of this very process, and you'll probably have to pay for that, and for sure have to sign an NDA.
- - - Updated - - -
... are model files greter than level 49 PTM models or BSIM models...
First see
my answer to cyrax, pls., for differentiation between BSIM models and BSIM parameter files.
BSIM
models are analysis models, e.g. called BSIM3, BSIM4, BSIM6, BSIMSOI.
BSIM (model)
parameter files are those used for one (or more) of these a.m. BSIM models, with level=49 and above (e.g. 54 mainly for BSIM4).