Thermal oxidation of InAlP

Producing insulating layers on III\u2013V semiconductors is crucial for a number of important device applications. Al-containing thermal oxides on AlGaAs and InAlAs have been found to possess good insulating characteristics and oxides on InAlP have recently been shown to be even more promising. This paper presents data on the thermal oxidation at 500\ub0C in moist nitrogen (95\ub0C) of MBE-grown InAlP layers (In0.525Al0.475P and In0.494Al0.506P) lattice matched to GaAs. The oxides (20\u2013300 nm thick) have been characterized by Auger electron spectroscopy, X-ray photoelectron spectroscopy, Rutherford back-scattering spectroscopy, transmission and scanning electron microscopy. Oxides are amorphous and appear to be a mixture of indium phosphates and aluminum oxide. The oxidation kinetics are parabolic, and the InAlP layer with the higher Al content oxidizes slightly faster. Electrical measurements performed on metal-insulator-semiconductor (MIS) structures indicate that the oxide has good electrical properties, exhibiting low current densities (up to 14 V), making the oxide films potentially useful for some device applications.NRC publication: Ye