Producing ripple topographies by ion bombardment with codeposition of impurities: A curvature-dependent sputter yield is not required

Abstract

We show that if impurities are deposited obliquely on a solid surface during normalor near-normal-incidence ion bombardment, a previously unconsidered surface instability can produce surface ripples. The concentration of the atomic species with the lower sputter yield is greater at the crests of these ripples than at their troughs. The instability can set in even if the curvature dependence of the sputter yields is negligible and the two atomic species are completely miscible.