Try LPCVD Nitride for KOH etching. Ziaur Rahmanwrote: I need to do anitropic etching of Si and planning to etch around 200 um. As we do not have DRIE we have to do wet etching. I tried KOH solution with different kind of masks like PECVD Nitride, Cr, Cr and Gold. But nothing survived more than 2 hours. So I am planning to use TMAH for etching. What kind of material can survive without peeling for more than 3 hours in TAMH? I want to use sputter Cr. Is it a good idea? I know a lot of people are using oxide and nitrides. But I prefer to use Cr as I have to etch for long time. Any suggestions, comments will be highly appreciated. Pramod Gupta 21084 Red Fir Court Cupertino, CA 95014 Phone: (408) 253-1646