[mems-talk] un-steep wall for AZ 4620

[Zhang Xiao Qiang]

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 at 70C and 2min at 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 at 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?

Any suggestions and recommendations are welcome! Thanks in advance!

Dr. Zhang XiaoQiang
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Singapore-MIT Alliance
Department of Materials Science and Engineering
National University of Singapore
Email:smazxq at nus.edu.sg
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