Hi wang.,

Which surface you mean..Is it the mask (PR mask for
electroplating??) ...Then Dilute your pH (Alkaline
solns attack PR much faster). May be you can do a long
hard bake also.

Chromium will generally form Chromium oxides at the
surface bcos of its inherent property.So may be you
can go for Au Deposition (may be 250 Angstoms enough)
over chromium without switching of Vacuum. what is the
surface reoughness ???100's of angstroms??

Higher C.D also gives higher surface roughness ..

So go for optimised Current.density (really tough..or
you have to search from literature..)

Then if more thickness variation is there,Increase
your ACD (anode cathode distance as well).You can do
some Pulse reverse plating.

You can do plating in your lab.No clean room is
generally required..

If nothing works for thickness., finally you can go
for CMP.(chemical mechanical polishing)

Bala,
Mcmaster university.



--- "J.J wang"  wrote:

> Thanks for your suggestion. I redid my experiment,
> the result turned out to be much better. This time
> 1) I use Chrome as seed layer, 2) Bigger copper
> plate as anode, 3) the current density is about
> 10ASF. 4) The substrate is glass slide. 5) The
> solution I used is EPI E-Brite Ultra Cu.
>
> This time the copper did grow on the seed surface
> proportionally to the plating time. However I still
> have some problems: 1) When the plating time is less
> than 90 seconds. The surfaces seem fine. When
> exceeding 90 seconds, the surfaces trend to swell.
> 2) The plated surface was pretty rough.
>
> Did the swollen problem have anything to do with the
> glass substrate ? And was the rough surface a result
> of unclean seed surface ? I didn't do the plating in
> the clean room but in the regular lab.
>
> Thanks for your patience to read my mail.
> Best regards
> J.J. Wang