Electrical properties of radio frequency magnetron-sputtered (Ba,Sr)TiO3 thin films on indium tin oxide coated glass substrate

Abstract

(BaSr)TiO3 thin films were deposited on an indium tin oxide (ITO)-coated glass substrate at the different substrate temperature of 350, 450, and 550-degrees-C by means of rf magnetron sputtering method. The dependency of dielectric constant (epsilon') and loss (tan delta) of (BaSr)TiO3 thin films as a function of frequency (0.3-1000 kHz) was studied. It was observed that there was a possibility for the oxidation of the ITO layer to be one of the causes of dielectric anomalies around 100 kHz. Dielectric constant and tan delta became larger with the increase of deposition temperature. As the deposition temperature increases, the leakage current also increases and the breakdown field decreases from 2.5 to 1.97 MV/cm. These variations of electrical properties can be clearly explained by the increase of mobile carrier-oxygen vacancy-in (BaSr)TiO3 thin films.