Kim,

I'm wondering how deep your etch is. In my experience it is tricky to go
beyond 50-100 um with mask except SiO2 or best LPCVD Nitride mask.

At one point I was using SU-8 as an etch mask for Quartz wafer channels
and having similar problems with lift-off and tried Omni-coat. In this
application it was not helpful and I eventually changed the process flow
entirely.

Good luck, and let me know if you find a good solution.

Thanks,
Rob MacDonald
Shearwater Scientific