I have not had any success processing dyed SU8 (avail from MicroChem as
SU8 20 B).  I have a 200 micron thick layer, and only the very top 50
microns or so becomes polymerized after UV exposure.  This is true even
after a very long exposure.  The developer dissolves the unexposed
areas, but then proceeds to undercut the crosslinked top layer.  After
enough time, the entire top layer is lifted off.

The dye in the resist is supposed to give it sloped sidewalls after
development, according to MicroChem, but I can't seem to even get it to
develop right.  Does anyone out there have any suggestions?  I have
tried reaching MicroChem directly, but their technical staff has been
unavailable.

Marc DeVincentis
marcd@ucla.edu