Preparation of Ferroelectric Bi₄Ti₃O₁₂ Thin Films with c-Axis Orientation by Atmospheric-Pressure Metal-Organic Chemical Vapor Deposition

Abstract

Ferroelectric Bi 4 Ti 3 O 12 thin films were prepared by the metal-organic chemical vapor deposition (MOCVD) method at atmospheric pressure using Bi( o -C 7 H 7 ) 3 and Ti( i -OC 3 H 7 ) 2 (DPM) 2 as metalorganic sources. Assist Ar gas flow rate effects on the growth of the thin films were also examined. Thin films obtained were characterized by XRD analysis, SEM, AFM and D-E hysteresis loop observations. Most of the single-phase Bi 4 Ti 3 O 12 thin films with c -axis orientation were deposited on Pt/Ti/SiO 2 /Si and Pt substrates above 500° C. Completely c -axis-oriented Bi 4 Ti 3 O 12 thin films were prepared on Pt plates at 600° C, which showed good ferroelectric properties: remanent polarization of 1.0 µ C/cm 2 , coercive field of 18 kV/cm and leakage current on the order of 10 -9 A/cm 2 .