Wet thermal oxidation of AlInAs and AlAsSb alloys lattice-matched to InP

The wet thermal oxidation of AlAsSb and AlInAs lattice-matched to InP is investigated. The oxidation kinetics are determined as a function of temperature and oxidation duration for both materials. The Al content in the material is found to modify the kinetics: the higher it is, the lower the oxidation temperature which can be used. Both oxides are characterised by optical and electron microscopy, by SIMS and by X-ray diffraction. High oxidation selectivity towards the other materials is obtained with AlAsSb. However, an interfacial layer, composed of pure Sb and As and textured on InP, forms during the oxidation process. In contrast, during AlInAs oxidation, such interfacial layer do not form but the oxidation selectivity is not so good. Finally, the electrical characteristics of the AlAsSb oxide are determined.