Processing and dielectric properties of sol-gel derived bst thin films

Abstract

Abstract The processing and dielectric properties of BaxSr1-xTiO3 (x = 0.0–1.0) thin films prepared by a sol-gel method were investigated. The films were prepared using solutions consisting of acetate powders and titanium IV isopropoxide in a mixture of acetic acid and ethylene glycol. Processing parameters were optimized to develop stable solutions which yielded relatively low crystallization temperatures. Electron microscopy techniques were used to examine the grain size and microstructure of the thin films. The grain size was on the order of 50 nm and had a marked effect on the electrical properties of the films. Properties such as dielectric constant, dissipation factor and leakage current were also measured as a function of film thickness. A dielectric constant ranging from 200 to 625 was obtained for BST films with x = 0.6 over a thickness range of 100 to 900 nm. Leakage current densities of the films remained below 0.1 μA/cm2 for extended time periods when measured at an applied field of 75 kV/cm.