Introduction of Impurities in Anodically Grown Silica

Abstract

The effects and mechanisms of incorporating phosphorus and sulfur during the anodic growth of on the properties of silica have been studied. The experimental techniques used were: chronopotentiometry, ellipsometry, and Auger depth profiling. It was found that the growth rate of the silica increases substantially at constant current with the amount of phosphorus or sulfur present in the oxide. The role of the impurities in increasing the growth rate of the oxide is clarified by experimental evidence, and a possible mechanism for the high electronic current flow during anodization is given. It is shown both by Auger measurements and by hysteresis in capacity/voltage plots that ions mobile at room temperature are present when the phosphorus and the sulfur impurities are present in the oxide.