Pulsed laser deposition preparation and properties of SrBi₂Ta₂O₉ thin films

Ferroelectric SrBi₂Ta₂O₉ (SBT) thin films were fabricated on low temperature platinized silicon substrates using pulsed laser deposition technique combined with annealing process, and structural and electrical properties were investigated. The SBT thin films with fine grain size and well-saturated square hysteresis loop were obtained. The films showed high diffraction peaks of (115) and (008). A dense structure with around 200 nm grain size was observed using the plane-view transmission electron microscope. The interface between the SBT film and substrate was very sharp as determined by cross-section transmission electron microscopy micrograph. Good ferroelectric properties were obtained from the films; P_r and E_c were about 10 μC cm^-2 and 57 kV cm^-1, respectively. No fatigue was observed up to 10¹⁰ switching cycles. These properties are very attractive for nonvolatile memory application.