The structural and dielectric properties of sandwiched PZT thin films

The sandwiched Pb_1.1(Zr_0.4Ti_0.6)O₃/Pb_1.1(Zr_0.6Ti_0.4)O₃/Pb_1.1(Zr_0.4Ti_0.6)O₃ [PZT(4060)/(6040)/(4060)] thin films were deposited by RF sputtering method on the Pt/TiO₂/SiO₂/Si substrate. We investigated the effects of deposition conditions on the structural and electrical properties of sandwiched PZT thin films. All sandwiched PZT thin films show dense and homogeneous structure without the presence of the rosette structure. The dielectric properties such as dielectric constant, loss, remanent polarization and leakage current density of the sandwich PZT thin film were superior to those of single composition PZT(4060) and PZT(6040) films, and those values for the sandwiched PZT thin film annealed at 650degC were 913, 3.06%, 15.2 muC/cm² and 2.57times10^-9 A/cm² at 5 V. This study suggests that the design of the sandwiched PZT thin films capacitor with tetragonal and rhombohedral phase should be an effective method to enhance the dielectric and ferroelectric performance in devices.