Hello, all? I am making some microchannel. For channel etching, someone recommended to use TMAH etchant as an isotropic etchant for Silicon instead of DRIE dry etching which is my preferred method. But, as far as I know, TMAH is an anisotropic etchant of Silicon similar to KOH. What I know as the isotropic etchant of Silicon is HNA(HNO3+H2O+NH4F). Can the TMAH be isotropic? And can photoresist be a mask for TMAH and HNA wet etching? Thank you and have a happy new year. Chang. ===== Chang-Hwan Choi Brown University Division of Engineering, Box D Providence, RI 02912, U.S.A. Tel: (401)867-6017(H), (401)863-2656(O), Fax: (401)863-9028 Email: chchoi@rocketmail.com, Chang-Hwan_Choi@Brown.edu __________________________________________________ Do You Yahoo!? Yahoo! Photos - Share your holiday photos online! http://photos.yahoo.com/