Preparation, microstructural and electrical characterization of SrTiO3 thin films prepared by chemical route

Polycrystalline SrTiO3 thin films having a cubic perovskite structure were prepared at different temperatures by the polymeric precursor method on pla tinum-coated silicon substrate. Crystalline films with uniform composition and thickness were prepared by spin-coating and the post-deposition heat tr eatment was carried out at different temperatures. The film showed good str uctural, dielectric, and insulating properties, Scanning electron microscop y (SEM) micrographs showed no occurrence of interdiffusion between the bott om electrode (platinum) and the film during post-annealing, indicating a st able interface between the SrTiO3 and the bottom electrode. The dielectric constant and dissipation factor at a frequency of 100 kHz were 250 and 0.01 , respectively, for a 360 nm thick film annealed at 600 degreesC. The capac itance versus applied voltage characteristics showed that the capacitance w as almost independent of the applied voltage. The I-V characteristics were ohmic in low fields and a Schottky emission and/or Poole-Frenkel emission w ere postulated in high fields. Room temperature leakage current density was found to be in the order of 10(-7) A/cm(2) for a 360 nm thick film in an a pplied electric field of about 100 kV/cm. The charge storage density of 36 fC/mum(2) was obtained in an applied electric field of about 100 kV/cm. (C) 2001 Published by Elsevier Science Ltd. All rights reserved.