PROBLEM TO BE SOLVED: To avoid increase of a driving voltage and characteristic reduction by reducing a stress which is applied to a piezoelectric thin film during polarizing processing and performing the polarizing processing on the piezoelectric thin film up to near an interface with a ground layer, in a piezoelectric element which is driven according to a d33 system.SOLUTION: A piezoelectric element comprises a substrate including an opening, a diaphragm, a piezoelectric thin film, and a plurality of electrodes. The diaphragm is formed on the substrate so as to cover the opening. The piezoelectric thin film is formed at a side opposed to the substrate with respect to the diaphragm and vibrates the diaphragm. The plurality of electrodes are provided so as to apply an electric field to the piezoelectric thin film approximately in an intra-plane direction, The piezoelectric thin film is comprised of a (001) orientation film of a rhombohedral crystal.COPYRIGHT: (C)2013,JPO&INPIT【課題】d33方式で駆動される圧電素子において、分極処理時に圧電薄膜にかかる応力を低減し、下地層との界面付近まで圧電薄膜を分極処理することにより、駆動電圧の増大および特性低下を回避する。【解決手段】圧電素子は、開口部を有する基板と、振動板と、圧電薄膜と、複数の電極とを備えている。振動板は、開口部を覆うように基板上に形成される。圧電薄膜は、振動板に対して基板とは反対側に形成されて、振動板を振動させる。複数の電極は、圧電薄膜に対して略面内方向に電界を印加するように設けられている。上記の圧電薄膜は、菱面体晶の(001)配向膜で構成されている。【選択図】図4
