The migration of the {112} incoherent twin boundary in nanotwinned Cu under electric current stressing was observed using in situ high-resolution transmission electron microscopy. The current-driven incoherent twin boundary migration was found to be four orders of magnitude faster than that driven thermally. It was proposed that electric current played a role in shuffling Cu atoms at incoherent twin boundary/coherent twin boundary junctions, which enhanced the nucleation of {112} steps and facilitated twin boundary migration in Cu. By understanding how twin boundaries responded to electric current forces, it was possible to trace the property changes in nanotwinned Cu under electric current stressing, which would provide an essential assessment of interconnect reliability.

Stability of Nanoscale Twins in Copper under Electric Current Stressing. K.C.Chen, W.W.Wu, C.N.Liao, L.J.Chen, K.N.Tu: Journal of Applied Physics, 2010, 108[6], 066103