Abhay,

To answer your second question: when you had gold on Si, the reflow that
you saw was for the AuSi eutectic ( AuSi eutectic point 363 C). To avoid
this, you would need a barrier layer on top of Si as mentioned by Roger.

Thanks
Sumant Sood


-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Roger Shile
Sent: Friday, September 19, 2008 12:55 PM
To: General MEMS discussion
Subject: Re: [mems-talk] Effect of high temperature on gold.

I've experienced spikes (probably a crystal formation) forming in a gold
film when heated to 400-500 degC.  The stack consisted of 1um SiO2/300nm
Cr/600nm Pt/1um Au on a Si wafer.

Roger Shile