Ferroelectric SrBi 2 Ta 2 O 9 (SBT) thin films on Pt/ZrO 2 /SiO 2 /Si were successfully prepared by using an alkanolamine-modified chemical solution deposition method. It was observed that alkanolamine provided stability to the SBT solution by retarding the hydrolysis and condensation rates. The crystallinity and the microstructure of the SBT thin films improved with increasing annealing temperature and were strongly correlated with the ferroelectric properties of the SBT thin films. The films annealed at 800°C exhibited low leakage current density, low voltage saturation, high remanent polarization, and good fatigue characteristics at least up to 10 10 switching cycles, indicating favorable behavior for memory applications.

The polarization suppression and electrical properties directly associated with the electrical polarization fatigue in SrBi2Ta2O9system were systematically investigated using Pt/SBT/Pt capacitors. Three general observations were made after 109 switching cycles: (i) ∼95% of the remanent polarization was conserved, (ii) both high and zero bias field capacitance decreased, and (iii) leakage current density increased from approximately 10−7 to 10−5 A/cm2at ∼30kV/cm2. In addition, the “knee” field, at which the leakage abruptly increases, assumed smaller values with cumulative switching cycles. Temperature dependent leakage data was collected for both as-deposited and field-cycled samples. Based on these results, we propose the possibilities of enhanced concentration of charge carriers or additional reductions in interfacial conduction barriers. Motion of oxygen vacancies to less-shallow energy levels near electrode/ferroelectric interface may allow this mechanism to occur.