I have also noticed some detrimental effects of HMDS on SU8. What has
worked for me is an etch clean of the wafer, vacuum bake and then
quickly spin the SU8 while the wafer is still warm. The soft and post
bake have to be ramped very slowly, about 5C every 2 mins.


On Sat, Dec 11, 2010 at 11:14 AM, Bill Moffat
 wrote:
> Mikael,
>
>           There are far better chemistries for adhesion for SU8 than
> HMDS.  In fact I do not think HMDS has any effect on SU8 chemistry.
> When I get to work on Monday I will discuss with our senior process
> engineer Ken Sautter and send some suggestions for better chemistry and
> treatment.
>
> Bill Moffat