You can reduce it by leaving your wafer to relax for about 1 hour
before starting the softbake.

I have also experimented in the past with a low spin speed and
cleanroom wipe well soaked in acetone but this often went wrong and
made matters worse!


2008/10/24 郑瑞麟(Ruilin Zheng) :
> Hello,
>
> Thanks again!
>
> The edge bead exist on the SU-8 layer, and I checked samples to find out the
> stiction happens at or around the edge bead.
>
> And the humidity is not very different from before when stiction rarely
> happen, it is about 65-74%.
>
> By the way, there is  no edge bead remove facility in my spin-coater. Could
> anybody show me a simple measure to remove edge bead?