Studies on ferroelectric properties of sol-gel derived Pb(Zr0.53Ti0.47)O-3 using Ba0.5Sr0.5RuO3 as the conductive electrodes

Abstract

Pb(Zr0.53Ti0.47)O-3 (PZT) thin films with a (110) preferred orientation were prepared on Ba0.5Sr0.5RuO3 (BSR)/Ru/SiO2/Si substrates using a sol-gel method. The oxide bottom electrode, BSR, was fabricated at various temperatures on Ru/SiO2/Si substrates by rf sputtering. The annealed PZT films on BSR/Ru/SiO2/Si substrates exhibited improved crystallinity. The electrical properties of PZT films, such as the electric field (E) induced variations of the leakage current density, the dielectric constant, and the polarization were strongly dependent on the processing temperatures of the PZT films as well as the bottom oxide electrode. A typical PZT thin film annealed at 650degreesC on the BSR electrode, which was deposited at 450degreesC on the Ru/SiO2/Si substrate by a sputtering technique, has a leakage current of 2.7 x 10(-7) A/cm(2) at an applied electric field of 500 kV/cm and a dielectric constant of 968. From the polarization-electric field characteristics, the remanent polarization and coercive field of the PZT were found to be 38.9 muC/cm(2) and 59.6 kV/cm, respectively, at an applied voltage of 5 V. The PZT films exhibited fatigue-free characteristics up to similar to1.0 x 10(12) switching cycles under 5 V bipolar pulses. (C) 2004 The Electrochemical Society.