It's very tough to electroplate copper on an insulator- no electrons for the redox process. You need an initiator i.e. palladium to do this and the adhesion to SiO2 is lousy. You will have to evap or sputter if you need a good stable film. Shay -----Original Message----- From: mems-talk-bounces@memsnet.org [mailto:mems-talk-bounces@memsnet.org] On Behalf Of Cassie Iany Sent: Friday, June 27, 2008 6:17 AM To: mems-talk@memsnet.org Subject: [mems-talk] Electroless Cu plating Hello, I am doing Electroless Cu plating on SiO2 substrate. I found the solution can deposit Cu film on Si but not SiO2. I tried to use different self-assembly monolayer to modify the surface, but still not succeed. One thing I am concerned about the SiO2 substrate cleaned with Pirana solution has contact angle of 45 degree which is different from other reported contact angle (nearly Zero degree). I don't know how the difference comes. Appreciate if you share your experience and suggestion. Regards Cassie