Preparation of C-Axis-Oriented Bi4Ti3O12 Thin Films by Metalorganic Chemical Vapor Deposition

Abstract
Bi4Ti3O12 thin films were prepared on Pt/SiO2/Si(100), Pt/Ti/SiO2/Si(100) and sapphire (R-cut) by metalorganic chemical vapor deposition (MOCVD). Bi(C6H5)3 and Ti(i-OC3H7)4 were chosen as the metalorganic precursors. C-axis-oriented Bi4Ti3O12 thin films were grown on Pt/SiO2/Si (100) at 550°C. These films deposited directly on the substrates exhibit high loss and exhibit very rough surface morphology. However, a Bi4Ti3O12 film with a Bi2Ti2O7 buffer layer on Pt/SiO2/Si(100) exhibits very smooth morphology and are highly c-axis-oriented. This film shows remanent polarization of 0.6 µC/cm2, coercive field of 13 kV/cm and dielectric constant of 180.