It sounds as if you are exposing the wafer to oxygen in between the chrome
and gold coating. I bet the chrome is oxidizing, which will probably give
you problems with the gold adhesion. Most evaporators will allow you to
coat at least to different metals in one go. I would suggest addding a
little chrome on top of your chrome chrome coated wafer and then
depositing gold without breaking vacuum.

Maybe there's a way to clean the chrome of oxide, as well. I bet Kirt
Williams would know that.

Jesse Fowler
  UCLA/MAE Dept., 420 Westwood Plaza, Room 37-129, ENGR IV
  Los Angeles, CA 90095-1597 | (310)825-3977
"Facts are stubborn, but statistics are more pliable."
   -- Mark Twain

On Thu, 2 Oct 2003, [iso-8859-1] usual_suspects wrote:

> currently im having problems getting a good contact
> for gold layer with silicon coated with chromium as it
> peel off easily.i deposited the gold layer using
> e-beam evaporater and it started well but when i tried
> to pick up the wafer, the gold layer deposited on it
> seems to peel off very easily. Is there any way to
> make a better contact for the gold layer and silicon
> coated with chromium or will just annealing do the job
> of making the gold layer stick better. Thankx
>