Oxidation-induced electromigration failure of thin films of aluminium

Abstract

The failure mechanism of very thin films (<10 nm) of aluminium exposed to oxygen at atmospheric pressure was investigated. At an apparent current density of 100 A cm^-2 two distinct types of film resistance increase on oxidation were observed. During the initial increase, describable by the direct logarithmic law, the oxide thickness could be expressed in terms of the film resistance. The second resistance increase, leading to film failure, was consistent with electromigration induced by the thinning by oxidation of the cathode contact film junction.