Angle‐Resolved X‐Ray Photoelectron Spectroscopy Study for Reactive‐Sputter‐Etched GaAs Surface

Abstract

The chemical state and oxide layer structure of the GaAs surface after reactive sputter etching (RSE) with CCl~F~ gas were investigated by angle resolved x-ray photoelectron spectroscopy (XPS). From the XPS results taken at a low take-off angle, an As-depleted layer exists in the top surface. The RSE-GaAs surface oxide is found to be composed of two layers consisting of a Ga2Q first layer and a Ga20:~ + As20:, mixed second layer. The thickness of the top Ga~O~ layer increases with increasing bias voltage from 0 to 7~, while the mixed layer thickness is rather likely to be reduced. The total oxide layer thickness of the RSE-GaAs surface grows gradually thicker with increasing bias voltage over the 0.2-0.8 kV region and is nearly equal to that of the native oxide before etching unless the mirror gloss of the surface is destroyed by RSE.