Solution deposition processing and electrical properties of Ba(Ti1-xSnx)O3 thin films

Ba(Ti1-xSnx)O-3 (0 less than or equal to x less than or equal to 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 propel-ties 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 degrees 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(Ti0.85Sn0.15)O-3-Pt interface was determined to be 1.49 eV.