Properties of GaAs Oxides Prepared by Liquid PhaseChemical-Enhanced Technique

Abstract

The properties of GaAs oxides prepared by liquid phase chemical-enhanced oxidation (LPCEO) technique are investigated. The refractive indices of the oxide films appear to increase with oxidation time, and can be well controlled by the oxidation procedures. It has been found that the accumulation of As compounds within the oxides is the origin for the phenomena. Based on the current-voltage (I-V) characteristics of the metal-oxide-semiconductor (MOS) structures, the leakage current density of the oxide has been demonstrated to be low (∼ 2 × 10-8 A/cm2), and a high dielectric breakdown strength of ∼ 8 MV/cm is achieved. Finally, the complete chemical compositions from the oxide surface to the oxide-substrate interface has been determined by x-ray photoelectron spectroscopy (XPS) and secondary ion mass spectroscopy (SIMS) depth profiles.