Ti, Cr, Al and Ta metals are used generally as adhesion layers because they are extremely reactive to trace oxygen and form metal-oxide-SiO2 interfaces. You need some metal that will form a covalent oxide bond to the SiO2 surface and also will alloy with Pt. Noble metals such as Pd might not form a strong oxide. For example, Ni does not adhere strongly, and therefore needs an adhesion layer. Pt and Pd are in the same group. Another approach may be to use high energy sputtering, such as pulse sputtering. That method was used to make Ni metal adhere to lithium niobate without an adhesion layer. Good luck. Don Friedrich JDSU Santa Rosa, Ca Don.friedrich@jdsu.com -----Original Message----- From: Taekyung Kim [mailto:tkkim74@gmail.com] Sent: Wednesday, March 18, 2009 9:20 AM To: mems-talk@memsnet.org Subject: [mems-talk] Pd as an adhesion layer? Hello folks, I am looking for an adhesion layer between SiO2 and Pt. Since my process restriction, I can't use Ti, Cr, and Al. Is Pd a fairly good adhesion material for Pt-SiO2? Thanks TK