Effect of Sn grain orientation on formation of Cu6Sn5 intermetallic compounds during electromigration

Abstract

The effects of Sn orientation and grain boundary misorientation on formation of Cu-Sn intermetallic compounds (IMCs) during electromigration were investigated. Significant anisotropic diffusion of Cu in Sn grains was observed. Interfacial Cu-Sn IMCs may grow rapidly, dissolve, or remain intact, depending on the angle of c-axis of Sn grains with the electron flow. In addition, grain boundaries did not play an important role in Cu diffusion because they are mostly cyclic twins. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.