Hi,

With regard to Cu, try to apply the SU8 immediately following deposition to
minimise native oxide formation. Of course you could remove this with 10%
H2SO4, however, preventing/minimising formation in the first place usually
yields better adhesion results with resists in general.

You also have to consider residual film stress (tensile) in the SU8 film
itself. Optimise your baking times and exposure dosage to minimise this
stress. Once you achieve this, you can then move on to the use of surface
modifying chemicals.

Regards,

Michael

>From: Zhiyan Liu 
>Subject: [mems-talk] Adhesion problem of SU-8 on metal surface
>
>I am trying to pattern SU-8 on the Cu seed layer and then do electroplating
>of Cu. I applied Omnicoat, which can improve the adhesion between SU-8 and
>metal layer according MicroChem, beneath the SU-8. But right during the
>development, some of the SU-8 is gone. Then in the following electroplating
>process, almost all the SU-8 is gone.
>
>Does anyone can give me a hint on the improvement of SU-8 on metal such as
>Au or Cu?