Abstract
We propose a new micro-fabrication process of piezoelectric MEMS actuators composed of lead-free KNbO_3-NaNbO_3 (KNN) thin films. The micro-cantilevers were fabricated on silicon on insulator(SOI) substrates, and successively the KNN thin films were directly deposited on them by rf-sputtering. Thus, piezoelectric unimorph micro-cantilevers of lead-free KNN films could be prepared without microfabrication of the KNN films. The dielectric properties of KNN thin films on micro-cantilevers were as good as those on the substrate. When we applied voltage of 20V, we could obtain relatively large tip displacement of up to 5.8μm and the average piezoelectric constant d_<31> was calculated to be -47.4pm/V. This fabrication process is useful for various applications of MEMS devices with new functional materials such as lead-free piezoelectric KNN films.
