well, thank you all at first.

It works as I doubled the exposure dose. But the inclined sidewall profile
still show up, but less severe, the slope is about 8/390, and still the
lower part close to wafer appears more inclined than the upper part near top
surface. The UV light source I am using is Karl Suss uv400, 10.7mJ/cm2 at
405nm, 4.9mJ at365nm, and a short peak at 334nm.

I also found a problem for the sidewall surface, it is corrugated. Does this
problem have something to do with internal stress?



2008/4/25 Gareth Jenkins :

> Then Andrew's interpretation is correct. The SU-8 is being underexposed.
> Try increasing your exposure dose to begin with (the datasheets
> underestimate the required dose especially for thicker layers).
> A filter to cut out <360nm would also be a good idea for such a thick
> layer.
>

--
Best Regards,

郑瑞麟

Ruilin Zheng