The Effects of Copper on the Interfacial Failure of Gold Films

Abstract

ABSTRACTNanoindentation test techniques were combined with deposition of highly stressed overlayers to study the interfacial fracture susceptibility of gold-on-copper and gold-2w/o-copper alloy films. The gold-on-copper film blistered readily following deposition of stressed tungsten overlayers. Additional stress from nanoindentation was required to trigger delamination and blister formation in the gold-copper alloy film. Fracture energies were then determined using mechanics-based models. The results show that the gold-copper alloy exhibited higher fracture energies than the gold-on-copper films. This increase scaled with film strength suggesting that the higher measured fracture energies in the gold-copper alloy film were due to solid solution hardening.