creating CMOS simulation models

Hello all

I've posted a message before about introducing a new technology to
DFII environment on 02/10/2004(link is below). I almost understood the
basic concepts of designing a PDK. First of all, I need create a
library of models for simulation(I use spectre). Before that, I have
to create a technology file to start a schematic since I have to
attach to a technology file.

I would like to know fundamentals of creating a technology file(I
already have a technology file but the technology I want to use has
less metals layers and different rules, parameters) and how to create
simulation models(I didn't get simulation models from the foundry).
I've downloaded Cadence generic process design-kit. I also would like
to know if there is a way to adapt my technology to gPDK.

I really appreciate any guidance.

regards

Mehmet Solmaz


http://groups.google.com/groups?dq=...&lr=&ie=UTF-8&oe=UTF-8&group=comp.cad.cadence

 

to make a techfile you create a text file with different sections.
you basically define :

1) which are the layers in your technology (layerDefinitions section)
-layers have a name and a layer number (techLayers section)
-a layer can also have multiple purposes (techPurposes section)
the main purpose is "drawing" but you can also have "pin" "net" and
many others it's up to you and the way you design your PDK.
-the order of the layers (techLayerPurposePriorities) in which
order the layers are drawn on the screen
-the display information (techDisplays) associates eache layer-purpose
pair with a "display packet" which in defined in a .drf file and specifies
the way the layer is displayed (color, style, ...). here you also define
which layers are valid (ie appear in LSW) and visible by default.
2) rules applying to the layers (layerRules section)
- how the layers are translated into GDS2 stream format (streamLayers)
this is a very important part of the techfile which define the mapping
between
layers in you design (ie MET1, MET2, ...) and layer numbers in the final
GDS2 stream. this must be done in accordance with information from the
foundry, who assigns a GDS number for each layer.

there are many other things you can add to a techfile, but i think this
the required part.

refer to the "ascii technology file reference" about the syntax and things.

as for transistor models, it is simply a collection of parameters.
you cannot guess them if you don't get them from the foundry.
refer to spectre reference manual about the different model
parameters and their meaning.

http://groups.google.com/groups?dq=&prev=/groups?hl=tr&lr=
%26ie%3DUTF-8%26oe%3DUTF-8%26group%3Dcomp.cad.cadence

 

I don't have simulation models, but I have the HSPICE BSIM3 parameters
for nmos and pmos. How do I create simulation models by utilizing
these parameters? Is there a software to create simulation models or
can I change the parameters of existing models and use it in
simulation?

 

of course you can.
look in the spectre reference, in the components
section under bsim3. you'll only have to insert the
correct values for each parameter.
i think you can even use the spice model directly
by putting 'simulator lang=spice' at the beginning
of the file.