Ferroelectric properties of bilayer structured Pb(Zr0.52Ti0.48)O3/SrBi2Ta2O9 (PZT/SBT) thin films on Pt/TiO2/SiO2/Si substrates

Pb(Zr0.52Ti0.48)O3 (PZT) thin films with large remanent polarization and SrBi2Ta2O9 (SBT) thin films with excellent fatigue-resisting characteristic have been widely studied for non-volatile random access memories, respectively. To combine these two advantages, bilayered Pb(Zr0.52Ti0.48)O3/SrBi2Ta2O9 (PZT/SBT) thin films were fabricated on Pt/TiO2/SiO2/Si substrates by chemical solution deposition method. X-ray diffraction patterns revealed that the diffraction peaks of PZT/SBT thin films were completely composed of PZT and SBT, and no other secondary phase was observed. The electrical properties of the bilayered structure PZT/SBT films have been investigated in comparison with pure PZT and SBT films. PZT/SBT bilayered thin films showed larger remanent polarization (2Pr) of 18.37 μC/cm2 than pure SBT and less polarization fatigue up to 1 × 109 switching cycles than pure PZT. These results indicated that this bilayered structure of PZT/SBT is a promising material combination for ferroelectric memory applications.