The effect of a wet-oxidized AlAs cap layer and an AlGaAs interlayer upon the thermal stability of a Ga0.8In0.2As/GaAs quantum well was studied. The quantum-well interdiffusion rate was observed to increase with increasing Al composition of the AlxGa1-xAs interlayer, until x reached about 0.5. It then saturated at x-values greater than 0.5. When the oxidation was performed at 380C for 0.25h, the threshold x-value for the enhancement of quantum-well interdiffusion was found to be 0.3. It was confirmed that the quantum-well interdiffusion could be explained only when strain effects in InGaAs were taken into account.

J.S.Choe, S.W.Ryu, B.D.Choe, H.Lim: Journal of Applied Physics, 1998, 83[11], 5779-82