Hi Trent, That's odd, it sounds like you're doing everything right. I regularly ebeam evaporate a-si onto borosilicate glass with no problems and I would think quartz should be similar. I typically clean my glass in piranha (or recently nanostrip), rinse in DI water, and then dehydrate at 200C for a couple minutes before evaporating. My only suggestion is to try troubleshooting the problem by doing a run where you clean your substrate and just evaporate a-si without the litho step. At least that way you'll be able to say whether the litho step and the patterning of the resist are causing the problem. -Joe Grogan huang wrote: > Hi guys, > > I was wondering if anyone has had similar problem before and has come up > with a solution. I've had a lot of trouble trying to deposit and pattern a > 100nm thick a-Si layer onto fused quartz substrate. > > I tried liftoff and have been struggling trying to either it to stick to > the substrate. I tried piranha clean, RCA clean, HF dip, as well as having > a thin (200nm) CVD SiO2 first before Si deposition. Each time the film > washed away with 1165. For the lithography step, I've been using an > established bi-layer process with PMGI SF11 under AZ4110 and made certain > that no resist remained in open areas by overexposing/overdeveloping/over-O2 descuming. For the a-Si deposition, I've attempted both a high density plasma, SiH4-based 50C process and e-beam evaporation. I'm going to try etching next. > > > Any input will be greatly appreciated. > > Trent