Surface infrared spectroscopy will be applied in this study of gallium arsenide anodic oxidation. The technique will be used both for the characterization of pre-oxidized gallium arsenide, and for investigation of the oxide as it is being formed. The surface infrared spectroscopy will be applied as an in-situ, multiple internal reflection geometry to directly measure the chemical composition and rate of growth of anodic oxides at the interface between gallium arsenide and the growth electrolyte. This will enable determination of the reaction mechanisms of the oxide growth, the chemical kinetics of the reactions, and the composition of the oxide layer produced. In addition, the effects of process parameters on kinetics and on composition will be investigated to determine optimum growth conditions. Advantages of native oxides as insulating layers on semiconductors include simplicity of processing, dependable film adhesion and system purity. The anodic oxidation process for gallium arsenide has been demonstrated as very promising. Previous studies have shown that the process is kinetically controlled, however the chemical kinetics and mechanisms of the oxidation reactions are not yet known. The successful passivation of gallium arsenide by native oxides has been a barrier to their full scale application in integrated electronics and optics.
