Electromigration-driven Evolution of the Surface Morphology and Composition for a Bi-Component Solid Film

TL;DR

This paper develops a PDE-based model to study how electric fields influence the surface morphology and composition of a bi-component alloy film, revealing differences from single-component behavior and sensitivity to electric field and anisotropies.

Contribution

It introduces a novel two PDEs model for alloy surface evolution under electric fields, accounting for anisotropic diffusional mobilities and analyzing stability and coarsening behavior.

Findings

Instability conditions differ from single-component films.

Wavelength and growth rate depend on electric field and anisotropy.

Scaling exponents are sensitive to electric field strength.

Abstract

A two PDEs-based model is developed for studies of a morphological and compositional evolution of a thermodynamically stable alloy surface in a strong electric field, assuming different and anisotropic diffusional mobilities of the two atomic components. The linear stability analysis of a planar surface and the computations of morphology coarsening are performed. It is shown that the conditions for instability and the characteristic wavelength and growth rate differ from their counterparts in a single-component film. Computational parametric analyses reveal the sensitivity of the scaling exponents to the electric field strength and to the magnitude of the anisotropies difference.