Asymmetry in electrical properties of Al-doped TiO2 film with respect to bias voltage

Abstract

The energy diagram of RuO2/Al-doped TiO2/RuO2 structures was estimated from the capacitance-voltage and leakage current density-voltage curves. The Al-doping profile in TiO2 film was varied by changing position of the atomic layer deposition cycle of Al2O3 during the atomic layer deposition of 9 nm-thick TiO2 film. The interface between the TiO2 film and the RuO2 electrode containing Al-doping layer showed a higher Schottky barrier by 0.1 eV compared with the opposite interface without the doping layer. The evolution of various leakage current profiles upon increasing the bias with opposite polarity could be well explained by the asymmetric Schottky barrier. (C) 2015 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim)