Natural oxides on air-exposed and chemically treated InGaP surfaces grown by metalorganic vapor phase epitaxy

摘要

Chemical properties of natural oxides on air-exposed and chemically treated In0.49Ga0.51P surfaces grown by metalorganic vapor phase epitaxy were systematically investigated by x-ray photoelectron spectroscopy. An air-exposed sample exhibited a highly In-rich surface which included a large amount of natural oxides. From the valence-band spectra and energy separations between core levels, it was found that the InPO4-like chemical phase was dominant in natural oxides of air-exposed InGaP surfaces. Chemical surface treatments in HCl and HF solutions were effective in reducing natural oxide and in recovering the surface stoichiometry.