Thermal Oxidation of GaAs in Arsenic Trioxide Vapor

A new technique for thermal oxidation of is proposed. The native oxide films composed of are plus thermally grown under controlled vapor pressures of arsenic trioxide. The breakdown strength of the films is found to be as high as , which is comparable with the highest value ever obtained for anodic oxide films. The leakage current is also on such a low level that it is of the order of 10 −8 A/cm 2 per 1000Å at an applied voltage of 10V. The chemical properties evaluated in terms of etching rates for various etchants exhibit satisfactorily stable and favorable characteristics for planar processes.