Investigation on Leakage Current Reduction of Photo‐CVD Tantalum Oxide Films Accomplished by Active Oxygen Annealing

Abstract

Previously, the authors demonstrated that photo‐CVD films formed on a Si substrate using and acquire very low leakage current by active oxygen annealing. This paper investigates in detail the mechanism of the leakage current reduction. Low‐leakage‐current films are produced provided there is a sufficient UV‐activation of molecules during CVD, an abundant supply of electronically excited oxygen, O(1D) and , during annealing, and Si migration from the substrate into the films during annealing, or CVD. A phenomenological model of the leakage current reduction is proposed. In the model, a certain void in the Ta‐O network is compensated by chemically incorporating a Si atom and several excited oxygen species; O(1D) or . This model can consistently interpret a series of phenomena on leakage current reduction reported in this paper and in our previous papers.