Comparison of silicon potentials for cluster bombardment simulations

Abstract

We have compared three common silicon potentials for molecular dynamics simulations of cluster bombardment of silicon structures. The potentials tested are Stillinger–Weber, Tersoff III and EDIP. We have also tested one variation of Stillinger–Weber and a variation of Tersoff III potential to see how small modifications of parameter values affect collision cascade and crater geometries. Single ion sputtering yields are compared to experimental values. In simulations, Si(1 1 1) surfaces are bombarded with 1–60 keV Ar 12 clusters. The potentials give almost similar overall description of collision cascades at different energies. However, measurable quantities like sputtering yields and crater sizes vary considerably between potentials and even between different parametrisations of the same potential.