The effect of O2 plasma post-treatment on atomic layer deposited TiO2 thin films

Abstract

In this study, we evaluated the changes of the properties of TiO2 thin films conducted to O2 plasma treatment at various plasma powers. The XPS analysis showed that the concentration of oxygen vacancies in the TiO2 thin films was reduced by the O2 plasma treatment. In the GIXRD analysis, it was confirmed that as the O2 plasma treatment progressed, the anatase peak intensity of TiO2 increased and a new anatase peak was detected. In addition, according to HR-TEM analysis the crystallinity became excellent. The AFM analysis showed that the roughness of the as-deposited TiO2 thin film and O2 plasma-treated TiO2 thin film were almost the same. The I–V analysis showed that the leakage current density of the 800 W O2 plasma-treated TiO2 thin film (∼10−4A/cm2) was 100 times lower than that of the as-deposited TiO2 thin film (∼10−2A/cm2). The dielectric constant of the O2 plasma-treated TiO2 thin films was approximately 24–25, which is higher than that of the as-deposited TiO2 thin film (k∼17) because of the anatase structure.