Hi Morten Thanks for sharing your process. I'm wondering if your setup causes problems with stiction? I mean moisture induced stiction for the released MEMS parts. Thanks Best Leo On Tue, Feb 3, 2009 at 11:10 AM, Morten Aarøewrote: > HF vapour etching is isotropic, so etching square 10µm x 10µm holes 10µm > deep is not possible. What you would get is at best a 20µm circular hole. > > I'm currently using this process to release fragile MEMS structures with > some success. It should be noted, that the only thing you need is a > container of 40% HF and a way to suspend your wafer above it (etch-side > down) in a fumehood- I use a PTFE/Teflon cylindrical shell with a slightly > smaller internal diameter than my wafer, which any workshop can make. The > etch rate is about 200nm/minute. We use 1.5µm AZ resist, but I can't tell > you if that's the best solution. It seems OK for 10µm etches though. > > // Morten Xiaoguang "Leo" Liu Birck Nanotechnology Center, Purdue University, 1205 W.State Street, West Lafayette, IN, 47906 USA liu79@purdue.edu