Hi Clara,

The best way to make sure you have current uniformity is to have a thin
seed layer of your plating metal onto the surface.  Is there anyway you can
sputter a thin layer of that?  Once you have had that layer, current
uniformity should not be a problem.  Current uniformity usually occurs from
the non-uniformity of the surface.  If your surface has protruded regions,
there will be a higher current density at those peaks, and the deposition
will be highly preferential at those points.  A seed layer will eliminate
that problem right away.  Hope this helps,