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Design >> RF Design >> layout problem about poly contact
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Message started by Tiger on Apr 1^st, 2011, 6:43am

Title: layout problem about poly contact
Post by Tiger on Apr 1^st, 2011, 6:43am

hi all,
for certain purpose, I'd like to layout each ploy finger with only one poly contact. Does this kind of layout is acceptable ? need your suggestion, and many thanks!

tiger

Title: Re: layout problem about poly contact
Post by rfcooltools.com on Apr 1^st, 2011, 12:24pm

tiger,

Here is how one could go about this. Ask the foundry for reliability information. If you can't get a response then view the layout for the digital library for the smallest inverter you can find and use as a minimum use the number of contacts in that layout. Finally expect that the fewer the contacts the more variation in the overall resistance between source/drain of the transistor and the metalization it connects to, so digital operation might be the only appropriate operation for this device.

http://rfcooltools.com

Title: Re: layout problem about poly contact
Post by Tiger on Apr 1^st, 2011, 6:47pm

thanks a lot, rfcooltools.com
yes, it is a problem about the reliability . i have checked out this kind of layout for digital circuit, and it is acceptable.
also, i view the standard rf Mosfet provided by the foundry. Though two poly contcact ared used to connect poly and metal1, it just uses only one via connecting the metal1 to metal2, from which the signal feed into the mosfet. So, i think the process provied by foundry is reliable, and this layout is acceptable.