Hi, all

These days got a lot of problem in SU-8 microchannel fabrication. I
tried to fabricate microchannel using SU-8 2050, after settle down
some alignment problem, I still cannot got the good sample while with
the SU-8 layer kept cracking or peeling off from substrate.

Here I gave the entire process I went through, could anyone give your
suggestion for my case.

Sub: square Si, with 2um PECVD SiO2 layer, and patterned EB evaporated
Cr/Au 150nm on it.

1) Hotplate: 150C to dehydrate 15mins
2) Spin coat SU-8 2050: 500/100/5s, and then 4000/1000/45s, suppose to
be 40um thick.
3) Softbake: 65C for 3mins, and cool down to room temperature, then
95C for 30mins.
4) Exposure: MA8 CI1 7mw/cm2 35s
5) PEB: 65C for 3mins then raise the temperature up to 95C and stay for 10mins.
6) Develope: SU-8 developer for 4mins.

Results: part of SU-8 pattern starts to peel off from sub after 1-2
mins rinse in developer, especially at the regions near microchannel
open or the edge of the Sub.

I am not doubting about the Exposure and PEB steps causing such
result. Could anyone advise me what dose and PEB process you adopted
for a sucessful SU-8 pattern.

Thank you very much!

Steven