X-Ray Photoemission Study of the Oxidation Process at Cleaved (110) Surfaces of GaAs, GaP and InSb

Abstract

The room temperature oxidation upon exposure to atmospheric dry O2 and thermal oxidation in air of some AIII-BV compounds have been studied by analyzing XP spectra quantitatively. For GaAs and Gap, evidences of the formation of metastable surface complexes by room temperature oxidation are shown: the values of the ratio of the oxidized AIII element to the oxidized BV element is about 2 and 1 for GaAs and GaP, respectively. For InSb, it is shown that both elements are oxidized to comparable extents, giving rise to In2O3 and probably Sb2O3. The rate of oxidation decreases in the order InSb>GaP>GaAs. The behaviors of thermal oxidation of GaAs and GaP are shown to be different.The formation of a GaPOx network which leads to GaPO4 at elevated temperatures is discussed.