SU-8 would work as an etch mask for KOH. The problem is, you will not be able to strip it. I am not sure if the approved strip method for SU-8 (lift-off using OmniCoat) would stand up to the KOH bath. Best Regards, Chad Brubaker -----Original Message----- From: galindo818@aol.com Subject: Re: [mems-talk] photoresist mask for KOH etching Carol, I don't think resist will work in KOH. I tried using photo resist in KOH it just dissolves. I use Nitride as a mask for KOH.