Hi,
Am trying to spin about 3-5 um of SU-8 onto a silicon wafer but was getting
some problems of adhesion and the SU-8 came off during the development step. I
read on this discussion group that HMDS was recommended to help with the
adhesion of thicker layers of SU-8. I tried spinning HMDS ar 5000 rpm/30 sec
before spin-coating the SU-8. However, during the pre-bake step (95 degrees
for 2 min), the layer of SU-8 shrunk from the edges of the wafer. What is the
reason for this and how can I prevent it if I want to use HMDS to aid SU-8
adhesion? Thanking you in advance.

Regards,
Melissa