The Designer's Guide Community Forum

The Designer's Guide Community Forum
https://designers-guide.org/forum/YaBB.pl
Modeling >> Semiconductor Devices >> How to import ESD diodes...
https://designers-guide.org/forum/YaBB.pl?num=1214970649

Message started by aaron_do on Jul 1^st, 2008, 8:50pm

Title: How to import ESD diodes...
Post by aaron_do on Jul 1^st, 2008, 8:50pm

Hi all,

I just got an ESD diode design from a certain company, but when i open the layout, there don't seem to be any pins or labels. So I don't know which connection is which. I was told there would be information in the .LEF file, but i had a look and i'm not really sure what to make of it. Does anybody have any experience with how to use an LEF file? Or maybe how to import the diode so that labels appear?

thanks,
Aaron

Title: Re: How to import ESD diodes...
Post by bernd on Jul 3^rd, 2008, 3:35am

Hi Aaron,

Your question is not very detailed.

What is you layout tool?
What is the file format to be imported LEF or GDSII?

How ESD diode much pins should your ESD diode have anode and cathode?
Can you not recognize this by the layers of the diode?
You may be able do do an LVS with a test design where your ESD diode is build
in and probe he stuff?

Bernd

Title: Re: How to import ESD diodes...
Post by aaron_do on Jul 3^rd, 2008, 6:58am

Hi,

I'm using cadence virtuoso. The file format is LEF.

the rest i don't really know. There was no schematic so i can't run an LVS, and there don't appear to be any labels. Even worse, when i import the diodes, the layers look different from the layers i'm used to using. I know roughly what the layers are, but i'm not really sure what an ESD diode looks like anyway.

Aaron

Title: Re: How to import ESD diodes...
Post by vivkr on Jul 3^rd, 2008, 7:34am

Hi Aaron,

Usually, ESD diodes are just like any other diodes. However, you would need to know which layer they were drawn in. It could be that the layout you have is the result of some processing on the original layout. I don't know if you have a standard GDSII or something else that you are looking at.

In this case, I would make a copy of the diode layout and then click on the layers to see the names. It could be that the layout has no "drawing" layers but "net" layers or something like this. You would only be used to the drawing layers, e.g. in the LSW, NPLUS (dg) and you might have NPLUS (nt) in the layout at present.

You can change all layers to drawing layers in a copy to get an idea of what you are actually looking at.

Regards
Vivek