I'm trying to fill some deep vias (25um wide, 70um deep) with resist. I
can't seem to get the resist to go any deeper than about 40um. The best results
were with using a PGMA pre-wet.  I've tried some 55cp resist that I coated three
times to fill (based on top down zygo) and some 120 cp resist. X-sections show
both resists to only be 40um down the vias.
    Any suggestions?

Robert