RPI and NBTI model equation

Hello everyone

I am working TFT AMOLED circuit design.

According to

Virtuoso® Simulator Circuit Components and Device Models Manual Product Version 7.1.1 June 2009,

Cadence Spectre and UltraSim simulators support RPI TFT model. The equations of RPI TFT models are listed in the above file.

I created the model card (.scs) for TFT and imported into Analaog Design Environemet (ADE) before running simulation, and it works.

However, what if I would like to modify the equations of the TFT model used in simulation? For example, when I read a paper talking about a new TFT device model, I would like to use this model in circuit simulation, so I need to modify the equation of the TFT model used in simulation. So, do I have access to the RPI model file used by Spectre or UltraSim? Can I modify that file? Where is the file?

The same question is for bulk-Si CMOS technology device models (e.g. BSIM3, BSIM4, etc)

Thank you very much!

Once you have run a simulation (so all is loaded) look at the model libraries
list. Your TFT model will be under one of the paths. You can edit it there or
put a softlink from it, to some other location (if it's not all locked up by the
CAD Police).

Cadence has a default $PROJECT_HOME/models/spectre search path that
will get picked up if it exists. Putting your simulation files there may be
the way to go, especially if you are prevented from editing the standard
ones. Copy the whole mess over and set it up "local".

dick_freebird said:

Once you have run a simulation (so all is loaded) look at the model libraries
list. Your TFT model will be under one of the paths. You can edit it there or
put a softlink from it, to some other location (if it's not all locked up by the
CAD Police).

Cadence has a default $PROJECT_HOME/models/spectre search path that
will get picked up if it exists. Putting your simulation files there may be
the way to go, especially if you are prevented from editing the standard
ones. Copy the whole mess over and set it up "local".

Click to expand...

Hello dick_freebird

Thank you very much for your reply!

In terms of physics, a device model contains two aspects: the equations describing the general relationships among parameters/variables, and the specific parameter values extracted from the characterization experiments on specific devices.

In your answer, it is still not clear whether you are talking about the files containing equations (i.e. the ones I am looking for), or the ones containing parameter values (i.e. model card, like .scs files). So, could you please clarify?

Besides, based on your hints, I have looked at the windows of icfb and spectre.out after simulation. The only files which look like possibly relevant to the files containing equations are listed in spectre.out as following:

Loading /CMC/tools/cadence/IC5141USR6_lnx86/tools.lnx86/cmi/lib/4.0/libinfineon_sh.so
Loading /CMC/tools/cadence/IC5141USR6_lnx86/tools.lnx86/cmi/lib/4.0/libnortel_sh.so
Loading /CMC/tools/cadence/IC5141USR6_lnx86/tools.lnx86/cmi/lib/4.0/libphilips_sh.so
Loading /CMC/tools/cadence/IC5141USR6_lnx86/tools.lnx86/cmi/lib/4.0/libsparam_sh.so
Loading /CMC/tools/cadence/IC5141USR6_lnx86/tools.lnx86/cmi/lib/4.0/libstmodels_sh.so

I opened the above files by using WordPad, but got messy codes in them. I guess this might be because these files are supposed to be protected by Cadence and thus encrypted.

So, still the question: how to modify the equations used in simulation?