Hello Vijay,

   If it is a polymer then oxygen plasma etching is probably a good
choice.  You will need a resist somewhat thicker than the BCB assuming
you would prefer not to use a metal masking layer.

-Michael

>>> Vijay Rajaraman  11/22/2010 6:12 PM >>>
Hello,

Has anyone successfully etched (selective or blanket) 10 microns of
cured BCB (cyclotene) or UV glue, landing on either Si or Al, without
residues ?

In case of selective etching, the preferred masking material is
photoresist.

Is there any good reference material on etching such thicker polymer
layers?

Do let me know.

Many thanks,
Vijay