A molecular dynamics simulation study of the influence of the ion-atom potential function upon sputtering

A molecular dynamics simulation has been used to investigate the ion-atom potential function dependence of single-crystal sputtering. Atom yields from the (111) and (001) crystal orientations have been calculated at 5.0 keV for the Cu/Ar+ system for 28 Born-Mayer and Moliere potential functions. The multimer yield ratios, layer yield ratios, ejected atom energy distribution, and angular distribution of ejected atoms are essentially independent of the potential parameters chosen in a Born-Mayer function. The atom yields from a target orientation can be ordered, or estimated, from a knowledge of the magnitude of the potential function in a sensitive range of separations near the maximum of the impact parameter distribution function for that surface. This property of the potential functions has been reproduced at 600 eV. The Moliere function yields and other properties fall exactly into the positions predicted from a knowledge of magnitude of the potential function in the sensitive range. With the exception of the atom yields, yield ratios, and the atoms per single ion distribution the properties of the sputtered atom distribution can be computed from any of a large number of potential functions.