Effects of Fluorine Plasma Treatment on the Electronic Structure of Plasma-Enhanced Atomic Layer Deposition HfO2

Abstract

We investigated the effects of fluorine treatments on the electrical properties and electronic structures of plasma-enhanced atomic layer deposition HfO2 gate oxides, depending on the treatment process. Pre- and postoxide-deposition fluorine treatments were carried out using CF4 plasma. Improved dielectric properties were achieved by predeposition treatment, while degradation of electrical properties was observed for postdeposition treatment. Based on the electronic structure analysis using X-ray photoemission spectroscopy and near-edge X-ray absorption fine structures, we found that the enhanced dielectric properties of the pretreated HfO2 are induced by the defect passivation and conduction-band offset increase. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3089976] All rights reserved.