Hi,

   I do not think that the stress is the only problem. You might need
another layer of metal to improve the adhesion between the gold and
Nickel layers or use a metal like copper, if possible, for your seed
layer. It makes sense that the bottom surface of the Ni layer is smooth
because it is grown on top of the gold layer. However, as the Ni film
grows thicker it becomes rougher (you can reduce the roughness by
modifying the DC plating current (which is common for Ni plating) or by
pulse electroplating.

   Good luck,
   Behraad


>
> Subject:
> [mems-talk] Nickel adhesion with gold seed layer
> From: "g.balsubra manian" 
> Date: Fri, 30 Jun 2006 09:42:25 -0700 (PDT)
> To: [email protected]
> To: [email protected]
>
> Guys.,
>
> I electroplated Ni on Gold/Cr/Si (gold is seed layer).
> But after few hrs.,Nickel adhesion is lost and gets
> peeled off. I suppose this is due to the stress
> initiated during Ni electrodeposition.
>
> When viewing under microscope, The top surface of
> Peeled Ni is rough., Bottom surface is very smooth.
>
> Whether increasing the roughness of seed layer either
> by plasma oxidation technique will help???.
>
> Thanks
>
> Bala.
>