Fine-Grained SrBi2Ta2O9 Thin Films by Low Temperature Annealing

A new low pressure annealing method for preparation of SrBi2Ta2O9 thin films is proposed. These thin films were prepared on Pt/TiO2/SiO2/Si substrates by the metalorganic decomposition (MOD) method, and their structural and electrical properties were investigated. Low pressure annealing was performed at 650°C for 60 min in a 2 Torr oxygen ambient per coating. The films were well crystallized and exhibited fine-grained and dense structures with grain size of about 50 nm. Pr=4.9 µC/cm2, Ec=24 kV/cm, IL=8.6×10-8 A/cm2 at a applied voltage of 3 V and breakdown voltage (VB) of over 20 V were obtained for the 200-nm-thick films. Futhermore, in the 100-nm-thick SBT film, a saturation voltage of 1 V was obtained. Pr=3.6 µC/cm2, Ec=25 kV/cm, IL=5.5×10-8 A/cm2 at 1 V and VB was over 10 V. Therefore, this method is very useful for highly integrated ferroelectric nonvolatile memory application.