What are your feature sizes (beyond 100 micron depth)? On Wed, Jan 4, 2012 at 7:50 AM, Ned Flanderswrote: > Thanks Bill, > > Thing is, I was really hoping I'd get a "no way" or "yay go for it" > kind of answer, as the experiment would take half a day, which right > now I don't have. > > Instead of chromium I could use tungsten, which also doesn't etch in > the phosphoric acid, while aluminum won't etch in hot H2O2, as far as > I know. Would that be a better electro-couple from the POW of > undercut? For the record, I don't need to remove the inorganic mask > after the last aluminum etch step. > > > best > > m