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

The room temperature oxidation upon exposure to atmospheric dry O 2 and thermal oxidation in air of some A III -B V 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 A III element to the oxidized B V 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 In 2 O 3 and probably Sb 2 O 3 . 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 GaPO x network which leads to GaPO 4 at elevated temperatures is discussed.