On the direction of electromigration in gold thin films

The motion of gold atoms during electromigration in thin films is shown to be in the direction of the electron flow, i.e., from cathode to anode. This is contrary to other observations reported in the literature in which holes are seen in the anode regions. In the present work, holes at the anode were produced by transient annealing effects of nonequilibrium grain structures and not by reversal of the direction of the electromigration. Holes can be regularly produced in either anode or cathode regions depending upon test conditions, preannealing, and heat sinking.