The Cr & Au are diffusing during 350C step.  You can either remove the
heat treatment or use Mo layer as a barrier between the Cr & Au.

Dan Ruiz

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Heiko Prüßner
Sent: Thursday, April 03, 2008 2:42 AM
To: General MEMS discussion
Subject: [mems-talk] Hf resistant Adhesion layer for Au on Si

Dear all,

I had a 20nmCr/ 200nmAu film sputtert on silicon. This setup has been treated at
350°C for an hour. At the final Hf etching step which I used to remove the
BOX of an SOI wafer the Au film peeled of.

Does anybody have an explanation? Do I need a diffusion barrier between the Cr
and the Au? Or has anyone a suggestion for another adhesion layer?