Oxidation Mechanism of Ultra Thin TiN Films Prepared by an Advanced Ion-plating Method

Abstract

We deposited ultra thin TiN films with thickness as small as 5–40 nm using an advanced ion-plating (AIP) methods. The films showed a slight resistivity increase in air. In this paper, we investigated the mechanism of the resistivity increase by using x-ray photoelectron spectroscopy (XPS) measurements. We found that the TiN film after 1000-hour exposure to air was the mixture of TiN, intermediative TiO_xN_y and TiO₂. We thus supposed that the resistivity increase was mainly due to high-resistivity oxidized species. We concluded that the structural change proceeded in two steps in the ultra thin TiN film: TiO_xN_y compounds were formed uniformly over the entire region of the film prior to the TiO₂ formation.