Monte Carlo model of topography development during sputtering

Abstract

A Monte Carlo computer model has been developed to describe a surface undergoing low energy (<keV) ion bombardment. The model incorporates angle-dependent sputter yields, angle-dependent reflection of energetic particles, random redeposition of sputtered material, and random surface migration of impurities. The model is two-dimensional and describes a surface in cross section as a line. The initial surfaces can be of any general form, not necessarily simple geometrical forms as in some earlier models. Two general results have been developed with this model. The first is that with the inclusion of sputtering, reflection, and redeposition, structures are developed similar to those observed experimentally. These features are temporary, however, and will be eventually eroded. If surface diffusion to a nucleation site is included as well, stable, enlarging structures are formed.