Hello – I’m having trouble with resist adhesion. I see this primarily after the development step. After developing, the resist sometimes peels off in certain areas. I’m using Si wafers that I cleaned with acetone and IPA. Any ideas what might be wrong?
Try adding an O₂ plasma clean before coating. Even after solvent cleaning, there’s often organic residue that prevents proper adhesion. A short descum (about 1 min) usually helps
Also, make sure your wafers are dry — any humidity can cause poor adhesion. After cleaning, bake them for a few minutes on a hotplate (around 115 °C) right before spinning.
And check if you’re touching the wafer surface with gloves during handling. Finger oils can cause random spots of poor adhesion.
What is the resist? I usually prep by using a piranha clean when I am using the EBL MaN resist. (Also in my opinion totally necessary for SU-8 resist as well)
Also some groups use Surpass or HMDS, but again, it all depends on the substrate / resist pair.
Adhesion issues can be tricky!
Thanks all! The pre-bake and plasma clean fixed the problem — all features now stayed on the substrate after development
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