BaTiO3 (BTO) thin films doped with various Sc contents up to 1.1 atom % sputter deposited on Pt/Ti/SiO2/Si substrates were prepared and characterized. The leakage current densities of BTO films were strongly dependent on the Sc content. After annealing at 600 degrees C, the leakage current density measured at 100 kV/cm was 7.1 x 10(-6) A/cm(2) for a 1.1 atom % Sc-doped film, about 3 orders of magnitude lower than 3.7 x 10(-3) A/cm(2) for a pure BTO film. The relatively low leakage current densities of the doped films are thought to be attributed to combined effects of refined grain structures and oxygen vacancies, as confirmed by transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3526596] All rights reserved.