The growth mechanism of thin oxide films on Si

Abstract

Recent isotopic tracer studies of silicon oxidation have suggested that, while thick oxide layers grow by the motion of interstitial O₂ molecules, thin (<50 Å) layers might grow by the motion of a defect in the oxide network. In this paper the defect involved is identified as being the valence-alternation centre O₃ ⁺, a formally positively charged trivalent oxygen site. A description is given of the migration of the defect under the influence of an electric field which arises from the presence of negatively charged traps at the external oxide surface, producing a Cabrera-Mott type growth mechanism.