Hi.

I am using az4620 PR for my deep drench like MEMS fabrication.  I have
about 8 um of PR on top of Si.  When I etched it on DRIE for about 2 hr,
I got no pattern at all on the Si.

I believe that the problem was that the PR residue was on top of Si
which prevented the etching of the Si.

Currently, I am using Karl suss at 6 mw/cm2 with exposure time of 70"
and 2min. in the az400k developer.

Anyone can help me how to develope az4620 PR?

thank you.

Indy Lee