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

Highly crystallized and (100)-oriented barium titanate thin films having a composition of Ba(Zr0.12Ti0.88)O-3 (BZT) were deposited on (100)-textured L aNiO3 electrode by rf magnetron sputtering at temperature from 300 to 550 d egrees C. The films had a very flat interface which was epitaxially bonded to the LaNiO3 electrode. However, the film deposited on Pt electrode was on ly weakly crystallized and had a rugged film/electrode interface. Satisfact ory dielectric constant of value around 220 similar to 270 was achieved for the films of 50 nm thick when deposited on LaNiO3 electrode at temperature s of 400 similar to 550 degrees C, while a much lower dielectric constant w as 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, less than or equal to 10(-9) A/cm(2), was m aintained before reaching an onset voltage as high as similar to 5 V, as co mpared to the film deposited on Pt electrode. It was also found that the cu rrent emission of the BZT thin films deposited on LaNiO3 followed the relat ion of Schottky emission, and a high Schottky barrier of 0.73 eV was evalua ted from the temperature dependance of current emission. (C) 2000 Elsevier Science Ltd and Techna S.r.l. All rights reserved.