Improvement of wet oxidized AlAs through the use of the In/sub 0.05/AlAs/AlAs/In/sub 0.05/AlAs sandwich structure

Recently, the native oxides of Al(Ga)As has attracted much interest due to their use in distribute Bragg reflectors in vertical cavity surface emitting lasers and insulating buffer layers for metal-oxide-semiconductor field-effect transistors. Many studies have been performed to characterize these oxides and it was found that pure AlAs caused problems with device processing and reliability. The addition of a small amount of Ga was shown to solve the problems associated with pure AlAs, but the oxidation rate varied with Al mole fraction is slowed down. We found that the addition of In had the same effect on the AlAs oxidation, the better thermal stability and lower oxidation rate. In this letter, we present the oxidation characteristic of the In/sub 0.05/AlAs/AlAs/In/sub 0.05/AlAs sandwich structure, which can improve both the thermal stability and oxidation rate greatly.