Selective epitaxy of GaAs on indium oxide mask followed by in situ removal of the mask

The selective epitaxy of GaAs has been investigated on indium-oxide films prepared by vacuum deposition. It was found for the first time that gallium atoms supplied on the indium-oxide surface were absorbed into the oxide, resulting in the suppression of GaAs deposition on the oxide. The selective epitaxy on a patterned indium-oxide mask and subsequent in situ removal of the mask by radical hydrogen irradiation have been demonstrated. The investigation shows that indium oxide is a promising mask material for in situ processing since selective epitaxy up to 550 °C and in situ removal of the mask can be achieved on any kind of semiconductor.