Morphological changes of Cu surfaces by comparison of Ar~+ and Xe~+ ion irradiation induced by photoemission-assisted plasma

摘要

A photoemission-assisted plasma (PAP) ion source with Xe excimer lamp (h=7.2 eV) has been developed to flatten Cu surfaces below 1 nm for achieving surface activated bonding at RT without pressurization. For this sake, ion beams with ion energy E_(ion)<50 eV are demanded to avoid sputtering-induced roughening. In this study, the momentum transfer effect of ion irradiation on flattening of Cu surface has been clarified by comparison of Ar~+ and Xe~+ ion irradiation.