Prakash Mukre wrote:
> I am trying to deposit SU-8 over thermal oxide. SU-8 is part of the final
> device I am fabricating, so I want it to adhere to the substrate
> strongly.
> But with my current recipe SU-8 delaminates after development.
> Following are
> the some process specs I am following.
>
> SU-8 2100 Thickness: 200-250um
> Softbake: 15min @65C, 100min @95C.
> UV Dose: I have tried 400mJ/cm2 to 1000mJ/cm2
> Hard Bake: 5min @65C, 20min @ 95C.
> Development time: 10-20min.
I assume you mean post exposure bake not hard bake (I wouldn't bother
with a hard bake). A low temperature post exposure bake may help reduce
stress in the film. Maybe try around 55C for several hours. Also make
sure you ramp up and allow it to cool down with the hotplate.