Dear Iskandar,

You can first deposit 50nm Cr + 200 nm gold layer on a silicon wafer and
then deposit SU-8 and do the patterning. (you can also use copper, but it
oxidizes fast, so gold  is a good choice). You can also do electroless
plating for seed layer deposition. After patterning/sexposing, do a bit O2
plasma to ensure that SU-8 is removed completly (5-10 min will be ok).

For electroplating you can use pulse plating small current density ~ 5-10
mA/cm2. Pulse on time - 0.9 s, pulse off period - 0.1s.

I have seen from my experiments, that copper deposition is more at the edges
than the center part. This non uniformity is due to localized current
distribution at the corners. This non uniformity is an unsolved issue.

Hope, this information will help.

Thanks,
Pradeep Dixit


On 3/4/06, Iskandar Samad  wrote:
>
> Hi all, Im looking to electroplate some copper onto SU-8 photoresist and
> was wondering if anyone has had experience with this. Btw, the SU-8 has
> been prepatterned and cured on a silicon wafer.
>
> Are there any issues about whether the sputtered/evaporated seed layer
> (for plating) adheres well to the SU-8, and if so what material seed
> would you suggest? Is there any material I could pre deposit that could
> perhaps aid adhesion?