Area selective epitaxy of GaAs with AlGaAs native oxide mask by molecular beam epitaxy

We have carried out area selective epitaxy of GaAs on GaAs substrates using a native oxide film of AlGaAs as a mask material. By optimizing the AlAs fraction and the thickness of AlGaAs mask layer, well-defined area selective epitaxy has been achieved on (0 0 1) and (1 1 1)B GaAs substrates by migration-enhanced epitaxy. No discernible difference is observed in both the shapes and the facets of the grown structures between the growth using AlGaAs native oxide and SiO2SiO2 masks. It is found that the shape of the grown structures can be easily controlled by As4As4 pressure during growth. It has been proved that the AlGaAs native oxide film is useful as a mask material in area selective epitaxy instead of the SiO2SiO2 mask.