Structural and electric properties of BaSn_0.15Ti_0.85O₃ films on ITO/glass substrate by RF sputtering from powder target

BaSn_0.15Ti_0.85O₃ (BTS) ferroelectric thin films have been deposited on the tin-doped indium oxide (ITO)/glass substrate by RF sputtering from a powder target, and the structural and electrical properties of the BTS film are also investigated at various deposition rates. The results indicate that leakage current of the BTS film is strongly related to the deposition rate, which decreases with increasing deposition rates. The leakage current density of the as-prepared film for a deposition rate of 40 nm/min and thickness of 500 nm is lower than 1.5×10^-10 A/cm², while its dielectric tunability reaches 57.3% and dielectric loss remains only 0.01 at a bias voltage of 5 V. From SIMS depth profiling of as-prepared BTS films, the lower leakage current density of the BTS film at a faster deposition rate may be attributed to the sharper BTS/ITO interface with a low inter-diffusion that results from the high deposition rate and shorter deposition time.