Oxygen vacancy motion in Er-doped barium strontium titanate thin films
Date of Issue2006
School of Materials Science and Engineering
Amphoteric dopants are widely used in BaTiO3-based dielectrics to improve capacitor reliability. In this work, an analogous approach was explored for barium strontium titanate thin films. Ba0.7Sr0.3TiO3 thin films were prepared by chemical solution deposition. Er was used as a dopant to decrease the leakage current and improve the film lifetime under dc electric field. The (Ba+Sr) /Ti ratio in the precursor solution was modified to facilitate doping on the A site, the B site, or both the A and B sites. It was observed that when (Ba+Sr) /Ti=1, the dopant has little effect on the dielectric constant, but decreases both the loss tangent and the leakage current. A current transient (peak) was observed prior to resistance degradation in both the undoped and Er-doped samples and was related to oxygen migration under dc bias. It is shown that Er doping effectively decreases the oxygen vacancy mobility, which may lead to longer lifetime under dc field in thin film Ba0.7Sr0.3TiO3 capacitors.
DRNTU::Engineering::Materials::Microelectronics and semiconductor materials::Thin films
Applied physics letters
© 2006 American Institute of Physics. This paper was published in Applied Physics Letters and is made available as an electronic reprint (preprint) with permission of American Institute of Physics. The paper can be found at the following DOI: http://dx.doi.org/10.1063/1.2364127. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.