The effect of an annealing process on atomic layer deposited TiO2 thin films

Abstract

In this paper, we study the property changes in TiO2 thin films related to annealing under various conditions. XPS analysis showed that the concentration of oxygen vacancies in TiO2 thin films was reduced by annealing. In the case of annealing in an O2 and air atmosphere, the oxygen vacancy concentration was reduced to the greatest extent as oxygen diffused into the TiO2 thin film and rearrangement of atoms occurred. XRD analysis showed that the anatase structure of annealed TiO2 thin films was clearly present compared to the as-deposited TiO2 thin film. I–V analysis showed that the lower the concentration of oxygen vacancy, the lower the leakage current (O2 annealed TiO2: 10−4 A cm−2) than as dep TiO2 thin film (∼10−1 A cm−2). The dielectric constant of annealed TiO2 thin films was 26–30 which was higher than the as-deposited TiO2 thin film (k ∼ 18) because the anatase structure became more apparent.