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: mems-talk-bounces@memsnet.org [mailto:mems-talk-bounces@memsnet.org] 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