Hello Dhanamjaya

You can use any polymer while isotropic etching of silicon if you use xenon
difluoride. It will not attack your polymers. XACTIX is the overwhelming market
leader in providing equipment for XeF2 silicon etching. If you would like to
try it please give contact me and we can run some samples.

David Springer
XACTIX Inc.
412 381 3195
www.xactix.com