Characteristics of Bi4Ti3O12 thin films on ITO/glass and Pt/Si substrates prepared by RF sputtering and rapid thermal annealing

Bi4Ti3O12 thin films are deposited on ITO/glass and Pt/Ti/Si(100) substrates by R.F. magnetron sputtering at room temperature. The films are then heated by a rapid thermal annealing (RTA) process conducted in oxygen atmosphere at temperatures ranging from 550-700 degrees C. X-ray diffraction examination reveals that the crystalinity of the films grown on Pt/Ti/Si is better than that of the films grown on ITO/glass under the same fabrication conditions. SEM observation shows that the films grown on Pt/Ti/Si are denser than those grown on ITO/glass substrates. Interactive diffusion between the Bi4Ti3O12 film and the ITO film increases with the increase of annealing temperature. The optical transmittance of the thin film annealed at 650 degrees C is found to be almost 100% when the effect of the ITO film is excluded. The relative dielectric constants, leakage currents and polarization characteristics of the two films are compared and discussed.