Hi, Yes, I agree with taking extreme care with the cleaning step. I also found that without piranha cleaning and baking in the hotplate at >120C for 10-20min I was getting bad adhesion. SILICON RESOURCES (www.siliconresources.com) offer an adhesion promoter AP 300) for SU-8 on glass. I tried it and it seemed to have worked, but I think that still you need to perform the very good cleaning of the glass. Finally, I found very important to avoid thermal stress during the post bake and PEB step: finally I decided to ramp the T up very slowly and cooling it down by switching off the hotplate! But I did not have a good programmable hot plate but it will give you an idea of how sensitive it is! And after that it worked almost 100% of the times! Good luck! Sonia. -----Message d'origine----- De : Joseph Grogan [mailto:JGrogan@seas.upenn.edu] Envoyé : Monday, October 17, 2005 11:38 PM À : General MEMS discussion Objet : Re: [mems-talk] SU8 adhesion I agree with Thomas, coating a thin layer of SU8 is a good idea, however, in my experience I found liquid SU8 to cured SU8 adhesion to be poor unless the cured SU8 is first treated with oxygen plasma (150 watts for a minute or two...play around with that yourself for best results). That was just my experience though. You should give Microchem a call, I believe they manufacture some sort of adhesion promoter (I've seen it in our lab but never had to use it myself). In addition, I would suggest you give special attention to the way that you are preparing the glass surface. You should be doing either piranha cleaning followed by a good hot plate bake (150C for 20 min minimum), or acetone, IPA, DI water, bake followed by oxygen plasma cleaning. Baking is important, I found moisture to be a big source of problems for SU8 adhesion (even the humidity in the room can destroy your results). Lastly, I'm not sure if you're doing this, but when you're curing the PDMS, don't do it at a very high temperature. I believe Dow's product sheet recommends times and temperatures that go up to 140C for 20 min or something like that. I found curing at high temperature caused my SU8 to come off as well (I'm guessing due to differences in thermal expansion between the SU8 and glass substrate). So try to stick to 100C or less. good luck, Joe Grogan