Preparation and characterization of excimer laser ablation derived lead zirconate titanate thin films for micro actuators

Ferroelectric films of lead zirconate titanate (PZT) are currently attracting attention because of the large number of potential application in micro actuators, such as micro-mirror, micro-pump and multi-probe cantilever of AFM. In this study, thin films of Pb (Zr_0.52Ti_0.48) O₃ (PZT) 1.8 ∼ 2.0 μm thick on a Pt/Ti/SiO₂/Si substrate were prepared by excimer laser ablation and were crystallized by subsequent annealing. Crystalline phases in the PZT films were investigated by X-ray diffraction analysis (XRD). The microstructure and composition of the films were studied by scanning electron microscopy (SEM) and electron probe microanalysis (EPMA), respectively. The effect of the Pb content of the target on electrical properties of PZT thin films was investigated. The PZT films with a well-crystallized perovskite phase were obtained by adding 20 wt % excess PbO to the target and annealing at 750°C for 90 min. The remanent polarization and the coercive field of this 0.8 μm think film were 23.6 μC/cm² and 60.0 kV/cm, while the dielectric constant and loss values measured at 1 kHz were approximately 935 and 0.04, respectively. Our results demonstrate that a few micrometers thick PZT thin films derived by laser ablation for use in micro actuators is possible.