Structural and electrical characteristics of rapid thermally processed ferroelectric Bi4Ti3O12 thin films prepared by metalorganic solution deposition technique

Polycrystalline Bi4Ti3O12 thin films having layered perovskite structure were fabricated by metalorganic solution deposition technique on both Pt-coated Si and bare Si substrates at a temperature as low as 500 degrees C. The effects of post-deposition rapid thermal annealing on the structural and electrical properties were analyzed. The electrical measurements were conducted on metal-ferroelectric-metal capacitors. The typical measured small signal dielectric constant and dissipation factor at 100 kHz were 184 and 0.018 and the remanent polarization and the coercive field were 4.4 mu C/cm(2) and 84 kV/cm, respectively. The films exhibited high resistivity in the range 10(8)-10(12) Omega cm for films annealed at temperatures of 500-700 degrees C for 10 s. The I-V characteristics were found to be Ohmic at low fields and space-charge-limited at high fields. A V-3/2 dependence of the current was observed in the space-charge region. This could be explained by assuming the mobility to be field dependent since in thin films the electric fields are invariably high even at low applied voltages. (C) 1996 American Institute of Physics.