An optimized process for fabrication of SrBi₂Ta₂O₉ thin films using a novel chemical solution deposition technique

Abstract

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.

Improving the synthesis and properties of SBT thin films by using SBT seeds

“…After that exothermic effects associated to organics decomposition reactions describe the thermal evolution of the two SBT precursor gels up to 450 • C. When temperature increases beyond 450 • C strong exothermic effects dominate DTA curves of both seeded and unseeded samples. As already reported for a similar temperature range the exothermic effects originated from the burn out of residual organics and from SBT crystallization reaction may overlap and account for such broad and intensive peaks 9,10 .…”

Ferroelectric properties of alkoxy-derived CaBi4Ti4O15 thin films on Pt-passivated Si

“…The remanent polarization ( P r ) and coercive electric field (E c ) were 9.4 C/cm 2 and 106 kV/cm, respectively, at 11 V. Figure 4 shows the endurance behaviors of 650°C annealed CBTi144 thin film against a number of switching cycles with voltages of 5, 7 and 9 V and a pulse width of 10 Ϫ6 s. The polarization did not change after 10 11 switching cycles with voltages of 5 V, however, the polarization began to decrease after 7.2ϫ10 10 and 2.2 ϫ10 9 switching cycles with voltage of 7 and 9 V, respectively. The P-E hysteresis and fatigue properties of the stoichiometric CBTi144 thin film were comparable to those of SrBi 2 Ta 2 O 9 thin film, 9,10 of which the stoichiometry had to be precisely deviated in order to enhance the properties, although relatively high voltages were required with respect to the CBTi144 thin film. have been reported as about 150 and 0.1, respectively.…”

Crystal Phase and Orientation Control in Integrated Ferroelectric CaBi4Ti4O15 Using a Tailored Liquid of Alkoxides

“…Figure 5 shows the endurance behaviors of the randomly crystallized single‐phase CBTi144 thin film against a number of switching cycles with voltages of 5 V and a pulse width of 10 −6 s. The polarization did not change after 10 11 switching cycles. The P – E hysteresis and fatigue properties of the stoichiometric CBTi144 thin film were comparable to those of SrBi 2 Ta 2 O 9 thin film, 18,19 of which the stoichiometry had to be deviated precisely to enhance the properties, but relatively high voltages were required with respect to the CBTi144 thin film. Figure 6 shows the dielectric properties of the 650°C‐annealed CBTi144 thin film.…”