GaAs Oxidation and the Ga‐As‐O Equilibrium Phase Diagram

The phases formed from the oxidation of have been considered in the light of an estimated equilibrium Ga‐As‐O condensed phase diagram. Thermal oxidation leads to phases consistent with the phase diagram. Plasma oxidation and anodic oxidation lead to phases inconsistent with the phase diagram. Thermal annealing of the plasma and anodic oxide layers leads to reactions producing phases consistent with the phase diagram. It is concluded that plasma and anodic oxides are produced far from equilibrium and that the estimated phase diagram is a satisfactory approximation to the equilibrium ternary phase diagram.