Stability of nanoscale twins in copper under electric current stressing

Abstract

Migration of {112} incoherent twin boundary (ITB) in nanotwinned Cu under electric current stressing has been observed using in situ high-resolution transmission electron microscopy. The current-driven ITB migration is found to be four orders of magnitude faster than that driven thermally. We propose that electric current plays a role of shuffling Cu atoms at ITB/coherent twin boundary junctions, which enhances nucleation of {112} steps and facilitates twin boundary migration in Cu. By understanding how twin boundaries respond to electric current force we shall be able to trace the property change in nanotwinned Cu under electric current stressing, which would be an essential assessment of interconnect reliability. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3483949]