Mr. Westra,

AZ offers a thick resist, part # AZ P4620. The resist thickness is from about 5
to 10 microns, depending on spinning rpm. You will probably have to apply two
or three layers to satisfy your 20 micron thickness requirement.

AZ Photoresist Products is a subsidiary of Hoechst Celanese Corp.,
headquartered in Somerville, New Jersey. The phone # there is (908) 429-3500,
or you might also try (800) 515-4164.

Charles King
Research Assistant-UCLA Electrical Engineering Dept.
charlesk@icsl.ucla.edu