Manual editing of a p2lvsfile

Hi Slawa

I don't quite understand the question so I am going to make a guess:

You are wondering how the layers in the ictfile relates to the layers used in the rules file. The layers in the ictfile are termed as "process layers". The layers in the rules file are termed as "lvs layers" and are created for the purpose of lvs verification. These layers must be mapped to the actual process layer using the p2lvsfile or layer_setup file so that parasitic R and C can be calculated. E.g. by mapping lvs layers "m1" and "m2" to process layers "Metal1" and "Metal2" in the layer_setup file, qrc will know the distance between m1 and m2 through the thickness values in the ictfile and hence parasitic caps can be calculated.

lvs layers that are used in the mapping file should also be found in the lvsfile. Otherwise there will be compilation errors. Hope that this answers your questions.

Best regards
Quek

Hello Quek

In the question I spoke about those layers which is in ICTfile but are not present in LVSfile and also about layers "intermediate" which are created in LVSrule. That is, there are base layers of process: M1 M2 V1 V2 Poly DIFF diffRES NP etc, and there are layers which in LVSrule are created on their basis by certain rules (or, and, not). Here for example:

//////////////RULE_file//////////////////
NDIFF = DIFF AND NP
NACTIVE = NDIFF NOT diffRes


Where DIFF, NP and diffRES - base layers of the given technology and layer NACTIVE it is created  on their basis directly for verification.
In LVSfile about layer NACTIVE it it is not known, It is present but about its structure there is no information. 

///////////LVS_file///////////
connect M1 NACTIVE by CON

model = mos [NH], NH
element mos [NH] NGATEGX3 GP NACTIVE PSUB
Therefore my question also is devoted that how to declare the given layer in p2lvsfile

 On the first question:
In ICTfile there are layers which corresponds nothing in LVSfile. For example:

/////////////////ICTfile///////////////////////
# Diffusion Layers
diffusion NPJunc {
   thickness         ///
   resistivity       ////
}
# dielectric Layers
dielectric   STI {
   conformal            FALSE
   height               ////
   thickness            ////
   dielectric_constant        ////
} 

 How to designate the given layers in p2lvsfile and whether it is necessary to designate them in general.

 If them to ignore in p2lvsfile that Techgen writes:

 WARNING (CAPGEN-41446): Substrate layer 'STI' will be automatically generated
 during extraction due to incomplete p2lvs mapping. This may lead to unintended results.

Best regards

Beginner engineer from Russia 

Hi Slawa

You will only need the layers that are listed in the lvsfile. There are many layers in the rules file and as you have noted, most are just intermediate layers that need not be mapped. The lvsfile rules file contains the important lvs layers that directly contribute to connectivity and device formation. Some level of knowlege regarding the rule deck layers is needed in order to do the mapping in the layer_setup file.

The interconnect lvs layers are easy because they usually have names such as "m1_conn" or "m1" or "metal1", etc. For the other process layers such as such as STI and NPJunc, we have to figure out the corresponding lvs layers. Look for names such as source_drain, sd, psub, substrate, etc. In the lvsfile, take note of the layers that are connected through "contact" layer. Usually you would want to map such layers (e.g. psub, nimp, pimp, etc) to the process layers that represent substrate and diffusion.

By the way, please do not use p2lvsfile format as it has already been replaced by layer_setup file. You must provde some mapping to all process layers so that the extraction results can be accurate.

Best regards
Quek

Many thanks for the help. QRC successfully started. And concerning replacement p2lvsfile on layer_setup_file... unfortunately compilation in such mode (are not created RCXpsiceINIT, RCXdspfINIT). About the given problem I wrote in theme Techgen + RCXdspfINIT.

 How to be if a layer in ICT corresponds at once to two layers in LVSFILE? How it to define in p2lvsfile?

As has been mentioned layer_setup_file I will dare to ask at once a question not to create a separate theme. Whether identical structure at it in comparison with p2lvsfile? A method of experiment I have revealed only one difference... This requirement at one of them to " ; "at the end of line

Best regards

Beginner engineer from Russia 

Hi Slawa

I am also not sure about the cause of your compilation problem. Perhaps it would be good to get some help from Cadence support.

You can map multiple lvs layers to a single process layer as follows:
pro_layer=STI   ext_layer=nwell_conn,Nburied,psubstrate

Some p2lvsfile features such as specification of rho, temperature coefficient, etc have been shifted to the ictfile because we now use ictfile for both cell and transistor level simulation. Since you are learning about Techgen and QRC, it would really be better if you can start with layer_setup file and not p2lvsfile. The lack of a semi-colon at the end of the line in layer_setup file is just one of the differences that it has with p2lvsfile.

Best regards
Quek

 Many thanks for the help

Best regards

Beginner engineer from Russia