I've dug through the MEMS-talk archives trying to find out some info on wet
etching of Pyrex. Most of the posts address to deep glass etching and most
people use Cr/Au as etching masks. I want to do a shallow etch (4 um) instead.
Would photoresist be able to stand HF for such a shallow etch or Cr/Au still
need to be used? I also learned from the past discussion that photoresist does
not adhere well to Pyrex wafers. Is this true? This is the reason that Cr is
deposited before the photoresist, but what is the role of Au then?

Thanks,
Tom Fan