XPS study of incident angle effects on the ion beam modification of InP surfaces by 6 keV O2 +

Abstract

The interaction of 6 keV oxygen ions with InP surfaces was studied as a function of O2 + ion incident angle. The bombarded InP surfaces were characterized in situ by x-ray photoelectron spectroscopy (XPS). The XPS measurements suggest that surface oxide layers formed by O2 + bombardment comprise a mixture of In2O3 and InP oxide. The degree of InP oxidation decreases with increasing incident angle. The O2 + bombardment also causes depletion of phosphorus from the surface region due to the preferential sputtering of phosphorus from InP. However, the preferential sputtering of phosphorus reduces with increasing incident angle. This decrease of the preferential sputtering of phosphorus is related to reduced oxidation when increasing the incident angle.