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