Surface Modification and Activation with Gas Cluster Ion Beam

Gas cluster ion beam (GCIB) was used for surface activation bonding (SAB). Since GCIB modifies only near surface, low-damage surface modification and activation are expected. In this study, Cu-Cu bonding with GCIB irradiation was selected as a preliminary study. XPS and contact angle measurement showed that surface oxide on Cu was removed efficiently by oblique incidence Ar-GCIB at 20 kV. Also, sequential irradiation of GCIB at normal and oblique incidence realized smooth Cu surface. Cu-Cu bonding did not succeced without GCIB irradiation or with 5 kV Ar- GCIB irradiation. On the country, Cu-Cu bondings were realized with 10 or 20 kVAr-GCIB irradiations owing to surface oxide removal.