Non-linear analysis of the morphological evolution of void surfaces in metallic thin films under surface electromigration conditions

Abstract

A theoretical analysis is presented of the non-linear dynamics of void surface morphology in metallic thin films under the action of an electric field that induces surface electromigration. Self-consistent dynamical simulations aided by the conclusions of linear stability theory reveal the important role of the anisotropy of void surface diffusivity, the strength of the applied electric field, and the void size in the dynamics. Special emphasis is placed on void dynamics in cases of low symmetry of surface diffusion anisotropy. Our simulations predict void faceting and wedge-shaped void formation, failure of the metallic films due to propagation of slit-like features from the void surface, as well as propagation of soliton-like features on void surfaces prior to failure. The simulation predictions are in excellent agreement with recent experimental observations.