| 摘要 |
PROBLEM TO BE SOLVED: To provide a piezoelectric actuator capable of, in a piezoelectric layer 25, reducing electrostatic capacitance in a wiring region Rby reducing a dielectric constant, while ensuring high piezoelectric characteristics in a displacement region Rby suppressing generation of crystal defects.SOLUTION: A piezoelectric actuator 21a comprises: a substrate 22; a first electrode (a lower electrode 24, for example); second electrodes (upper electrodes 26, for example); and a piezoelectric layer 25. The piezoelectric layer 25 has: first regions R1; and a second region R2 which is placed so as to surround the first regions R1 with planes thereof perpendicular in a thickness direction. Each of the first regions R1 has a displacement region Rwhich is displaced in accordance with a potential difference between the first electrode and the second electrode. The second region R2 has a wiring region Rwhich becomes a base of wires 51 for pulling out the second electrodes on the displacement regions R. The displacement regions Rhave a polycrystalline film 25a including a plurality of crystals. In the second region R2, at least the wiring region Rhas a modified film 25b where a grain boundary has disappeared because of temporary modification of the plurality of crystals.SELECTED DRAWING: Figure 2 |
