AC and DC electromigration in aluminum

Results are presented for experiments in which aluminum model contact asperity junctions are operated at current density up to 10/sup 6/ A/cm/sup 2/ with either DC or AC square wave current. Application of current as a square wave eliminates the possible influence of cyclic thermal stresses which could have been a factor in a previous study. Electromigration failure, observed as a relatively abrupt increase of resistance, occurs in both AC and DC specimens. Conditions under which electromigration deterioration may occur in practical aluminum power connections are discussed.