A molecular dynamics simulation of collisional excitation in sputtering from Al

Abstract

The molecular dynamics sputtering code SPUT2 was modified to permit investigation of core excitation in Al following bombardment with 5 keV Ar + ions. This code was used to investigate sputtering mechanisms responsible for the ejection of core-excited atoms from solid surfaces. Simulations were carried out with the ion incident along both low- and high-index directions. In contrast to most previous studies, essentially all ejection of core-excited atoms resulted from asymmetric collisions (i.e. collisions between the incident ion and a target atom). When the ion is incident along a low-index direction, core-excited atoms arise almost exclusively from the first layer of the target. When the ion is incident along a high-index direction, core-excited atoms are found to eject from deeper layers as well.