Low leakage BiFeO3 thin films fabricated by chemical solution deposition

Abstract

BiFeO3 (BFO) films were fabricated by spin-coating precursor solution on Pt/Ti/SiO2/Si(100) substrates through chemical solution deposition (CSD) technique. A pure perovskite phase was formed at annealing temperatures as low as 350°C for 10 min. The leakage current density decreased with annealing temperature until 500-550°C, and then increased again at 600°C. The lowest leakage current density obtained was about 10-6 A/cm2 at 100 kV/cm for the 500°C-annealed BFO film. The leakage current was found to be closely related to grain size and grain size distribution, indicating that grain boundary-related mechanisms dominate conduction. The dielectric constant increased with increasing annealing temperature from 90 to 120. The polarization-electric field curves could be obtained even in BFO films annealed at such low temperatures as 350°C. The remnant polarization remained relatively unchanged with annealing temperature, which was about 30 μC/cm2, and the coercive field had a value close to 80 kV/cm. © 2005 The Electrochemical Society. All rights reserved.