Preparation and properties of Bi4Ti3O12 thin films by electron cyclotron resonance sputtering

Thin films of ferroelectric Bi4Ti3O12 were deposited on Pt- or Ir- coated oxidized Si substrate by electron cyclotron resonance (ECR) sputtering using ceramic targets. Crystal structure and dielectric properties of the films were investigated as functions of sputtering conditions such as substrate temperature, sputtering gas pressure and used substrate. Using a target with excess Bi content compared to stoichiometric composition was required to compensate Bi re-evaporation from the substrate and to obtain a perovskite single phase at 600 degrees C. (117)-oriented films exhibited ferroelectric hysteresis loops The remanent polarization and coercive field of the Bi4Ti3O12 films on Pt/SiO2/Si were 10.9 mu C/cm(2) and 149 kV/cm, respectively. Those of the films on Ir/SiO2/Si were 3.6 mu C/cm(2) and 99 kV/cm, respectively.