Hello

I am using the su-8 spin coating on the silicon wafer. I expect a very flat su-8
surface because it determines the photolithography resolution. I always
failedandthe surface is clearly not flat (there is no bubble) even the su-8
reflow in the softbake process the bead edge can move to the inner.

Does anybody know how to make a flat surfacein the spin coatingprocesssuch as
the acceleration time and the last sudden accelerate 1000 rpm or something?

Any comments will be highly appreciated.

Kind Regards