Deposition and properties of highly (100)-oriented barium titanate thin films on LaNiO3 electrode

Abstract Highly crystallized and (100)-oriented barium titanate thin films having a composition of Ba(Zr 0.12 Ti 0.88 )O 3 (BZT) were deposited on (100)-textured LaNiO 3 electrode by rf magnetron sputtering at temperature from 300 to 550°C. The films had a very flat interface which was epitaxially bonded to the LaNiO 3 electrode. However, the film deposited on Pt electrode was only weakly crystallized and had a rugged film/electrode interface. Satisfactory dielectric constant of value around 220∼270 was achieved for the films of 50 nm thick when deposited on LaNiO 3 electrode at temperatures of 400∼550°C, while a much lower dielectric constant was obtained for that deposited on Pt electrode. More importantly, the films showed a very good insulating characteristic against biasing voltage, i.e. a low leakage current density, ⩽ 10 −9 A/cm 2 , was maintained before reaching an onset voltage as high as ∼5 V, as compared to the film deposited on Pt electrode. It was also found that the current emission of the BZT thin films deposited on LaNiO 3 followed the relation of Schottky emission, and a high Schottky barrier of 0.73 eV was evaluated from the temperature dependance of current emission.