Ion-Induced Surface Diffusion in Ion Sputtering

TL;DR

This paper quantifies how ion bombardment influences surface diffusion, showing it can both enhance and suppress diffusion depending on experimental conditions, affecting surface morphology and ripple formation.

Contribution

It introduces a calculation of the ion-induced diffusion constant and explores its dependence on ion energy, flux, and angle of incidence.

Findings

Ion bombardment can both enhance and suppress surface diffusion.

The sign of the diffusion constant depends on experimental parameters.

Ion-induced diffusion impacts ripple formation and surface roughening.

Abstract

Ion bombardment is known to enhance surface diffusion and affect the surface morphology. To quantify this phenomenon we calculate the ion-induced diffusion constant and its dependence on the ion energy, flux and angle of incidence. We find that ion bombardment can both enhance and suppress diffusion and that the sign of the diffusion constant depends on the experimental parameters. The effect of ion-induced diffusion on ripple formation and roughening of ion-sputtered surfaces is discussed and summarized in a morphological phase diagram.