Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.
They usually are square, but they can be rectangular, too. Important is that they are unique (all the same size). Contacts and vias are the most numerous data structures in a layout, so their OPC data prep CPU time has to be minimized, hence this uniqueness requirement, s. e.g. this thread.
It's about process control. You can tune an etch process for
one feature geometry much better than you can when it has
to cover a range - especially when the most-used is at the
barely-capable end of the tool set, you may need to favor it
to exclusion of other sizes (which otherwise would tend to
"blow out" larger than as-drawn, and any contact-defined
device attributes possibly be uncontrolled, or min-contact-
consistent overlap rules violated, or whatever).
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
