Pulsed anodic oxidation of GaAs for impurity-free interdiffusion of GaAs/AlGaAs quantum wells

The use of pulsed anodic oxidation of GaAs for impurity-free quantum well interdiffusion is demonstrated. The GaAs capping layer of a single GaAs/Al(0.3)Ga(0.7). As quantum well structure was oxidized and rapid thermal annealing (RTA) at 900 degreesC for 60 s was carried out to create atomic interdiffusion, X-ray photoeletron spectroscopy was used to study the anodic oxide both before and after RTA, The defects created in oxidized p-GaAs epitaxial layers were also studied using deep-level transient spectroscopy (DLTS), The possible mechanisms that generate excess gallium vacancies, V(Ga), during either the anodic oxidation process or RTA to promote interdiffusion of the GaAs/AlGaAs quantum well are discussed. Copyright (C) 2000 John Wiley & Sons, Ltd.