Solution deposition processing and electrical properties of Ba(Ti_1−xSn_x)O₃ thin films

Ba(Ti_1−xSnx)O₃ (0 ≤ x ≤ 0.3) thin films were deposited on a platinized silicon substrate by a solution deposition process with methoxyethanol, water, and propylene glycol as solvents. Dielectric properties and current–voltage characteristics of the thin films were investigated in conjunction with phase evolution and microstructures by varying heating temperatures and Sn contents (x). Thin films annealed above 700 °C showed a pure perovskite phase with nanoscaled grains (20–30 nm). The dielectric constant of the thin films depended on the Sn content and showed a maximum value of 330 at x = 0.15. The leakage current behavior of an optimum composition corresponding to x = 0.15 was examined by correlating with charge transport mechanisms. Schottky emission was found to be predominant at voltages less than 6.8 V, and Fowler–Nordheim tunneling appeared to be responsible above 6.8 V. The Schottky barrier of the Ba(Ti_0.85Sn_0.15)O₃–Pt interface was determined to be 1.49 eV.