Changes in the Surface Structure of ε-Cu₃Sn and η-Cu₆Sn₅ due to Sputtering

Abstract

Changes in the surface composition and structure of Cu₃Sn(ε-phase) and Cu₆Sn₅(η-phase) due to sputtering were examined by electron microscopy, electron microanalysis, and Auger electron spectroscopy.
It was found that with sputtering time, the Sn content in η-phase decreased as a result of its preferential sputtering but the composition in ε-phase remained unchanged. The sputtering yield of Sn in η-phase was larger than that of Cu. The surface condition in ε-phase became rugged with sputtering, and resulted in the formation of etch pits arrayed along the direction of scars produced during friction.