Oxidation of GaP in an Aqueous H 2 O 2 Solution

Abstract

The oxidation of gallium phosphide in aqueous has been accomplished by both galvanic action at about 106°C and by externally applied anodic reaction at room temperature. These oxides can be used as passivation materials in light‐emitting devices. A detailed examination of the kinetics of galvanic oxide growth indicates that the oxidation mechanism involves predominantly the transfer of holes, and the rate‐controlled step in the growth mechanism involves the diffusion of the oxidant through the growth oxide. The growth of an oxide by externally applied anodic bias has resulted in the fact that the oxide thickness depends linearly on the applied bias up to about 150V, with the proportionality constant being 13 Å/V. Uniform films can be obtained with up to 200V of forming voltage. In order to obtain a stable amorphous oxide, a drying procedure to remove the water of hydration is necessary for both methods.