It was pointed out that previous treatments of void shape change during electromigration had been restricted to non-singular void surfaces. The lateral spreading of a void was considered here for the case where its leading surface was a singular facet. The latter could nucleate at the leading surface of a void which migrated within one grain, or could develop when a singular surface was exposed by impingement of the void at a transverse grain boundary. A stationary void shape was possible when a certain dimensionless parameter was less than a critical value. When it was above this value, the void spread indefinitely.

X.Chu, C.L.Bauer, W.W.Mullins: Applied Physics Letters, 1997, 70[2], 194-6