It should work.  On the one hand, if I'm not mistaken the reason the Cr
is a good adhesion layer (or Ti, or Ta) is that it creates chrome oxide
at the surface of the oxide, which creates a good interface with the
silicon dioxide so that the gold adheres well to the Cr layer.  So, in
reverse, the Cr on top of the gold should become oxidized on top, either
by room air if you break vacuum or by the oxide deposition if you don't,
and so it seems the PECVD oxide would stick to the chrome oxide.  But I
have no direct experience with this particular combination.  I'd be
interested in hearing about your results, thank you.

PECVD oxide on aluminum is no problem, probably *because* of the
aluminum oxide.


Sjoerd Haasl wrote:

>Hello,
>
>To evaporate gold on oxide surface, usually one uses a layer of chromium
>or titanium as an adhesion layer.
>
>What now if I would want to deposit oxide (PECVD) on top of a gold
>surface. Should I put an adhesion layer on top of the gold? And if so,
>would it matter if I break vacuum while doing this? (i.e. I have to take
>the wafer from the evaporator to the PECVD, so the adhesion layer could
>oxidize a bit on the way.)
>The gold surfaces I am using are quite large (500microns x 5millimeters)
>
>Does anybody have any experience on this?
>
>Furthermore, should I expect problems when PEVCD oxide on aluminum?
>Again, I can imagine that the oxide layer on the aluminum could affect
>the adhesion.
>
>Thank you,
>
>Sjoerd Haasl
>
>