Dear Peter Are you suggesting to evaporate a Cr layer after developing the photoresist and no hardbake? Don't you think it could be a problem of the type of photoresist? Dear Barbara, Try to use a metal mask e.g. Cr. After patterneing the Cr layer don't remove the resit befor BHF etching.. regards, Peter Kuijpers Philips To "mems-talk"cc "Barbara Cortese" Subject [mems-talk] Quartz wet etching Sent by: Classification mems-talk-bounces@me msnet.org 2006-12-14 05:10 PM Please respond to General MEMS discussion Dear all I'm wet etching quartz with a BHF solution 6:1, but I have encounterd some difficulties in etching. What I do is a photolithographic process on the quartz substrate, a hardbake of 4 hours at 180° and then the wet etching process. What I obtain though is the rearrangement of the photoresist in a disordered pattern and no etching! Has anyone an idea where I go wrong? Barbara