Effect of substrate bias voltage on the structure, electric and dielectric properties of TiO2 thin films by DC magnetron sputtering

► TiO2 films were deposited by DC magnetron sputtering at different substrate bias voltages. ► The leakage current density decreased with the substrate bias voltage. ► Conduction mechanisms in TiO2 films were Schottky effect and Fowler-Nordheim effect. ► Dielectric constant increased with the substrate bias voltage. ► Optical band decreased with the increase of substrate bias voltage.