Structural, electrical, and optical studies on rapid thermally processed ferroelectric BaTiO3 thin films prepared by metallo-organic solution deposition technique

Polycrystalline BaTiO3 thin films having the perovskite structure were successfully produced on platinum coated silicon, bare silicon, and fused quartz substrate by the combination of the metallo-organic solution deposition technique and post-deposition rapid thermal annealing treatment. The films exhibited good structural, electrical, and optical properties. The electrical measurements were conducted on metal-ferroelectric-metal (MFM) and metal-ferroelectric-semiconductor (MFS) capacitors. The typical measured small signal dielectric constant and dissipation factor at a frequency of 100 kHz were 255 and 0.025, respectively, and the remanent polarization and coercive field were 2.2 mu C cm(-2) and 25 kV cm(-1), respectively. The resistivity was found to be in the range 10(10)-10(12) Omega.cm, up to an applied electric field of 100 kV cm(-1), for films annealed in the temperature range 550-700 degrees C. The films deposited on bare silicon substrates exhibited good film/substrate interface characteristics. The films deposited on fused quartz were highly transparent. An optical band gap of 3.5 eV and a refractive index of 2.05 (measured at 550 nm) was obtained for polycrystalline BaTiO3 thin film on fused quartz substrate. The optical dispersion behavior of BaTiO3 thin films was found to fit the Sellmeir dispersion formula well. (C) 1997 Elsevier Science S.A.