Paul,

    100um of resist suggests no need for high resolution, sub micron.
Simple plasma with an inert gas will abrade the surface and give more
surface area and good adhesion.  If chemical adhesion to the resist is a
must, the general problem is insufficient dehydration and then allowing
the wafers to see moisture before applying adhesion promoter.  If you do
a careful matrix doing one vacuum purge followed by a hot nitrogen gas
reduces rough edges by about 50% indicating a better adhesion.  A second
vacuum hot Nitrogen purge reduces rough edges even more.  A third
vacuum/hot Nitrogen purge removes all observable rough edges.  And a
final vacuum dehydration ensures complete adhesion.  Let me know if you
need any help.  Bill Moffat

-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Paul Nguyen
Sent: Tuesday, November 24, 2009 7:15 AM
To: [email protected]
Subject: [mems-talk] How to improve adhesion of resist to a metal
surface

Dear ALL,

Beside best surface cleanliness pre-coating, what other techniques would
improve adhesion of photoresist (very thick up to 100um) to a metal
surface, in particular a NiCo surface?  I would appreciate input from
MEMS experts.

Happy Thanksgiving to ALL!

Best regards,
Paul Nguyen