A role of illumination during etching to porous silicon oxidation

Abstract

The oxidation behavior of porous silicon (PS) has been found to be related to illumination during etching. The autocatalytic oxidation behavior at room temperature arises from the unrelaxed surface induced by the preparation under illumination and can be removed using thermal treatment in a nitrogen atmosphere. The effect is absent in the case of degenerate PS and smaller in p type than in n-type PS. The correlation between the oxidation behavior and the microstructural dimensions is also discussed.