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

Abstract

Bi 4 Ti 3 O 12 thin films were prepared on Pt/SiO 2 /Si(100), Pt/Ti/SiO 2 /Si(100) and sapphire (R-cut) by metalorganic chemical vapor deposition (MOCVD). Bi(C 6 H 5 ) 3 and Ti( i -OC 3 H 7 ) 4 were chosen as the metalorganic precursors. C -axis-oriented Bi 4 Ti 3 O 12 thin films were grown on Pt/SiO 2 /Si (100) at 550°C. These films deposited directly on the substrates exhibit high loss and exhibit very rough surface morphology. However, a Bi 4 Ti 3 O 12 film with a Bi 2 Ti 2 O 7 buffer layer on Pt/SiO 2 /Si(100) exhibits very smooth morphology and are highly c -axis-oriented. This film shows remanent polarization of 0.6 µC/cm 2 , coercive field of 13 kV/cm and dielectric constant of 180.