This sounds like the grass formation we had in the early days of
Silylation work.  The resist was exposed and the wafer exposed to a warm
gas containing a silyating agent usually HMDS.  This reacted with the
exposed areas giving a silicon rich protective shell.   Unfortunately
unexposed resist had small molecular levels of sensitizer that had been
destroyed giving the usual acid seen at exposure.  The silylating agent
reacted with these small levels and created dots of silicon rich
material.  After etching those dots that resisted the etching left grass
in the hopefully etched areas.  The quick fix was to do a few seconds of
fluorine plasma etch to remove the silicon rich speckles. I would
research early papers on Silylation, if this fails and you still think
this may be an avenue to explore, get back to me and I will try to find
early IBM and Intel papers on the subject.


Bill Moffat, CEO
Yield Engineering Systems, Inc.
2185 Oakland Rd., San Jose, CA  95131
(408) 954-8353