Theoretical Analysis of Electromigration-Induced Failure of Metallic Thin Films

A comprehensive theoretical analysis is presented of the failure of metallic thin films due to electromigration-induced morphological evolution of transgranular voids. Fully self-consistent dynamical simulations emphasize the important effects on void dynamics of the surface diffusivity anisotropy, together with the strength of the applied electric field and the void size. The simulation results are discussed in the context of an approximate linear stability theory. Our simulations predict formation of wedge-shaped voids, as well as failure due to propagation of slit-like features emanating from void surfaces, in excellent agreement with recent experimental observations.