Task is relatively easy.  With standard positive resist and ammonia
baked image reversal technique.  Resist up to 40 microns can be
patterned with side wall angles from -22 degrees, through vertical to
+22 degrees.  Contact me for technical papers and tests.
Bill Moffat, CEO
Yield Engineering Systems, Inc.
2185 Oakland Rd., San Jose, CA  95131
(408) 954-8353


-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Zhang Xiao Qiang
Sent: Wednesday, September 13, 2006 6:11 AM
To: [email protected].
Subject: [mems-talk] un-steep wall for AZ 4620

Dear all

I am trying to make the pattern size of few microns and the aspect
ration is 2:1 to 3:1 using AZ 4620. I found that it is difficult to get
the steep wall. The upper pattern is about 7-8 micron for designed 6
micron pattern after developing. My recipe is spin coating 20s+1600
rpm(about 12 micron), soft bake 1min@70C and 2min@100 C. leave the baked
samples for about one hour and then exposure 40 s using I line(365 nm,
10 mW/cm2). PEB 2 min@100 C. Develop for 2.5-3 min using AZ 400K : DI
water 3:1 developer.

Do you think I made any mistakes and the task is feasible?