Effect of an Electric Field on Silicon Oxidation

Abstract

Modified‐marker experiments have shown that silicon oxidation is controlled by the diffusion of oxygen through the silicon dioxide film. The application of an electric field across the silicon dioxide layer enhances oxidation when the silicon is made positive with respect to the oxide—gas interface, and retards oxidation when the silicon is negative with respect to the oxide—gas interface. Oxidation under a retarding electric field ceases when the voltage developed across the growing oxide is equivalent to the change in free energy of the oxidation reaction. The dependence of the oxidation rate on an electric field indicates that oxygen ions are the predominant species diffusing through the growing oxide film.