Dielectric properties of TiO2 thin films deposited by a DC magnetron sputtering system

Abstract

DC magnetron thin films were used to build up metal-oxide-metal (MOM), aluminum-TiO2-aluminum structures. Aluminum was deposited through thermal vacuum evaporation in a dedicated installation. The electrical polarization effect for the electric capacitance and dielectric loss and the behavior of dielectric properties of MOM structures with signal frequency and temperature were analyzed. We found that the amorphous TiO2-based MOM structures have an unusual dependence of dielectric properties on the polarization and signal frequency, in accordance with the higher value of the TiO2 dielectric constant. We observed that near 270 K there is a transition that occurs for the dielectric constant. This transition is consistent with incorporation of water and OH-ions in the film.