Hi

I had a lot of adhesion problems and lifting of the SU8 during the
development step and finally, the solution, was to ramp up and down all the
hotplate steps..... that really reduced the stress of the layers and
therefore the lifting of the patterns.

I agree in that the hardbake could induce further stress....... I also
observed that myself!

Good luck!

Sonia.

Chen Han Lee wrote:

>Hi all,
>
>I am wondering if someone can advise me on how to improve the adhesion
>between su-8 and oxide wafers.
>
>The su-8 film (20um thick) breaks and peels off from the wafer after KOH
>etch.
>
>I did hardbake the su-8 at 150C for 3 minutes after developing.