Structural, morphology and electrical studies on ferroelectric bismuth titanate thin films prepared by sol-gel technique

Crystal structure, surface morphology, compositional homogeneity and electrical properties of layered perovskite bismuth titanate (BTO) thin films have been investigated. BTO thin films were deposited on silicon and platinum-coated silicon substrates by spin coating. X-ray diffraction analysis confirms that the crystallinity of the films increases with increasing annealing temperature and the optimum temperature is found to be 600degreesC. Morphology studies by AFM showed that the surface of the films were smooth, dense and crack free. Composition analysis on the surface and indepth confirms the stoichiometry of the films. C-V measurements show a counter-clockwise dielectric hysteresis. indicating that the ferroelectric property sufficiently controls the silicon potential with a memory width of 2V. The leakage current density of the films is measured to be 2 x 10(-7) A/cm(2) from I-V characteristics at in applied voltage of 1 V. (C) 2002 Elsevier Science B.V. All rights reserved.