Growth of TiO2−δ thin film by RF magnetron sputtering using oxygen radicals and Ti metal

TiO2−δ thin films have been deposited by RF magnetron sputtering using oxygen radicals. The deposition rate of the thin films largely increases with oxygen radical irradiation during the deposition in the metal mode. A as-deposited TiO2−δ thin film on a Pt substrate prepared at the substrate temperature of 300 °C crystallizes without postannealing. The Ti 2p X-ray absorption spectrum indicates that the Ti 3d electron enters the bottom of the conduction band. The Ti 3d states at the Fermi level (EF) and at ∼1.5 eV from EF in the band gap energy region are closely related to the electrical conductivity.