Metalorganic chemical vapor deposition of ferroelectric SrBi2Ta2O9 thin films

Ferroelectric layered-oxides SrBi2Ta2O9 thin films were prepared on Pt coated Si wafers and single-crystal sapphire by metalorganic chemical vapor deposition (MOCVD). The films were specular and crack-free and showed complete crystallization at temperatures between 650 and 700 °C. Good ferroelectric properties were obtained for a 200 nm thick film with Pt electrodes: 2Pr and Ec were about 8.3 μC/cm2 and 60 kV/cm, respectively. The leakage currents were as low as 8×10−9 A/cm2 at 150 kV/cm. The films also showed fatigue-free characteristics: no fatigue was observed up to 1.4×1010 switching cycles. These high quality MOCVD films make high-intensity (≳1 Mbit) nonvolatile memory devices possible.