|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Electronic Packaging and Interconnections
||Cu-Cu bonding with silver thin film capping layer
||HSIANG HOU TSENG, Chih Chen
|On-Site Speaker (Planned)
||HSIANG HOU TSENG
Cu-Cu bonding has replaced solder joints for ultrahigh density packaging due to its scaling ability and low resistance. However, copper can be oxidized easily and it can lead to poor quality. A thin passivation capping layer is a method to resolve this problem.
We adopt Ag passivation to protect Cu from oxidation, because Ag oxides can be reduced to Ag over 180 C and Ag has the lowest resistivity. 100 nm Ti and 200 nm Cu were deposited by sputtering on Si (100) substrate as adhesion layer and seed layer, respectively. A highly (111) nanotwinned copper (nt-Cu) film was deposited on the substrate by electroplating and chemical mechanical planarization (CMP) was conducted. After that, a 20 nm silver film was sputtered on the nt-Cu film. Two specimens were bonded together under 1MPa and bonded at 200 ℃for 60 minutes successfully, and the results will be presented in the conference.
||Copper / Nickel / Cobalt, Thin Films and Interfaces, Other