Molecular Dynamics of Ion Incident Angle Dependence of Sputtering Yield in Chlorine-Adsorbed GaN Crystal

Abstract

A molecular dynamics simulation has been carried out to investigate the dependence of chemical sputtering yield on the ion incident angle in the wurtzite-type GaN(0001) surface with a Cl-adsorbed layer. The sputtering yields of both Ga and N atoms show only a weak dependence on ion incident angle for the range of 60 to 90° (normal incidence). Ga is chemically sputtered mostly in the form of Ga–Cl2, and sometimes in the form of Ga–Cl, Ga–Cl3, GaxNy, and GaxNyClz. These products escape from the surface in the time range of mainly 200–500 fs after the impact of the incident Ar ion. There are small amounts of products escaping in the time range of 500–5000 fs.