The influence of film thickness and process temperature on c-axis orientation of Bi3TiTaO9 thin films

Abstract

Bi-layered ferroelectric Bi3TiTaO9 (BTT) thin films with different thickness (ranging from 100 to 400 nm) were successfully fabricated on Pt(111)/TiO2/SiO2/(100)Si substrates using chemical solution deposition (CSD) technique at different annealing temperatures. The c-axis orientation of the films was affected by film thickness and process temperature. The thinner the film and the higher the process temperature, the higher the c-axis orientation. With the increase of film thickness, the stress decreased but the film roughness increased, which led to the decrease of c-axis orientation of films. BTT films annealed at 800°C were found to have much improved remament polarization (Pr) than that of films annealed at 650 and 750°C. The Pr and coercive field (Ec) values were measured to be 2 μC/cm2 and 100 kV/cm, respectively. BTT films showed well-defined ferroelectric properties with grain size larger than 100 nm.