Gold and Silicon will melt and form a eutectic at 363 C. Pure gold will melt
at 1064 C. Unfortunately, you will probably have to either drastically lower
your annealing temperatures, or change your metallurgy. You don't have too
many choices for metals that can withstand high temperatures. Tungsten might
survive, but it may be difficult to wirebond to. It's also brittle, and not
as electrically conductive as gold.

Bill Eaton, Ph.D.
Materials & Analysis Manager
NP Photonics

> -----Original Message-----
> From: mems-talk-bounces+bille=solustech.com@memsnet.org
> [mailto:mems-talk-bounces+bille=solustech.com@memsnet.org]On Behalf Of
> Zhengfan Zhang
> Sent: Wednesday, July 02, 2003 10:11 AM
> To: General MEMS discussion
> Subject: [mems-talk] Gold film fail at high temperature
>
>
> Hi,
>     I tried to heat gold film on silicon wafers with oxide
> layer to 900
> degree C for 10 minutes and all the film is blown out. The
> thickness of the
> gold is about 50nm with 4 nm Ti as adhesion layer. We heat it
> in air. I am
> not sure what could be a problem. Is it simplely that thin
> gold film can't
> sustain that temperature or something else. We did e-beam
> lithography so
> there is a chance that some resist is left under the gold. If
> that is the
> problem, how can we completely remove the resist residue. The
> resist is pmma
> and we did short time O2 plasma try to get rid of the
> residue, but it can't
> be removed thoroughly.
>     Best regards.
>
> Zhengfan Zhang
>
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