Dear all

I am also handling AZ P4620 now. I have read the data sheet provided by
the manufacturer. In fact there are two versions and they conflict each
other. If you are interested in, can download from there website but it
for 24 um.

I also was confused by the dose of print and found with low dose of
exposure you can not develop thoroughly. I can not get the steep wall
with recommended dose. My feather is hole with diameter of 6 um and
aspect ratio of above 2:1.

Best regards!

XiaoQiang


To: [email protected]
Subject: [mems-talk] Multiple coats of AZ P4620

Hi Abishek,
                     I have done two coats of AZ4620. Use HMDS before
the
first coat only. Spin the resist at the desired RPM and bake for 90 secs
at
110 deg. Let it to cool and spin the second coat and bake for 2 mins and
the
subsequent coat for about 4 to 5 mins. Prolonged bakes causes the resist
to
harden quite a bit and may need extended exposure and develop times. A
20 um
thick layer took me about 2 min 30 secs to develop in AZ 400K (1:3)

Saravana P. Natarajan
Grad. Research Assistant - RF Microsystems Group
University of South Florida,Tampa, FL,
Ph: 813-974-4851
Fax: 813-974-5250