Parasitic Extraction problem

Discussion created by freelectron on Apr 9, 2011
Latest reply on Apr 11, 2011 by freelectron

hi, all.

I came across parasitci extraciton problems when using calibre, hope someone can help me:

The process i used provides deep nwell(DNW) for pusb isolation. So for some NFETs, I had S and B connected together to a different potential(net, suppose its name is Vx) from Gnd.

When run calibre c+cc parasitic extracion, i found the parasitic lumped capacitors of  these NFETs, which are supposed to these isolated psub(net Vx), are to the whole pusb(net Gnd)~ Obviously, this is not correct.

So, how can i extract the parasitic capacitors correctly?


many thanks!