Gold atoms can move into the silicon layer and change the conduction/valence
band structure of silicon (you can find it in any books about semiconductor
physics).

You should employ another layer between Si and Au. The function of this
layer is to  prevent gold atoms from moving into silicon, Usually  Ti, Ti/W,
Cr, Pt are used. Another function is to make sure good contact between
silicon and gold, not only mechanically but also electrically.

In my experience, The Ohmic contact between Ti-Si, Ti/W-Si is good; while
Cr-Si is not as good.



2009/8/30 renil kumar 

> Hi All,
>
>                  Can gold be an electrical contact for n-type SOI wafer. I
> am planning to sputter gold on the SOI wafer as an electrical contact and
> bulk etch the silicon to form the electrostatically movable cantilever. Any
> suggestion would be appreciated.
>
> Thanks in advance.
>
> Renil

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