ARXPS study of the ion mobility through (HfO2) x(SiO2)1-x formed on air-exposed HfSi 0.5As1.5

Abstract

The oxidation of the (001 ) surface of HfSi0.5As1.5 exposed to the atmosphere, as monitored by angle-resolved X-ray photoelectron spectroscopy (ARXPS), gives rise to a slightly Si-rich (HfO2) x(SiO2)1-x film. As2O3 and SiO2 are present at the air-oxide interface, suggesting that both As and Si atoms can diffuse through the amorphous silicate film via vacancies, in the form of defects and interstitial sites. By exposing the surface over periods between 1 and 60 min, it was found that the oxidation of HfSi 0.5As1.5 follows logarithmic kinetics, indicating that the oxide film formed is passive. Copyright © 2008 John Wiley & Sons, Ltd.