Abstract: A piezoelectric device having a high conversion efficiency between electrical energy and mechanical energy is provided. The piezoelectric device has first electrode, a second electrode, and a piezoelectric layer provided between the first electrode and the second electrode, wherein the piezoelectric layer is formed of a ZnO-based material having a wurtzite crystal structure to which a metal that does not cause the piezoelectric layer to exhibit conductivity is added, and wherein a squared value of a electromechanical coupling coefficient in thickness vibration mode is 6.5% or more.

Abstract: A piezoelectric material is described. The piezoelectric material comprises aluminum nitride (AlN) doped with ytterbium (Yb), an atomic percentage of Yb in the AlN being greater than or equal to approximately 10.0% and less than or equal to approximately 27.0%. Piezoelectric layers comprising the piezoelectric material may be used in bulk acoustic wave (BAW) acoustic resonators, and surface acoustic wave (SAW) acoustic resonators. The BAW acoustic resonators and SAW acoustic resonators can be used in a variety of applications.

Abstract: A piezoelectric material is described. The piezoelectric material comprises aluminum nitride (AlN) doped with ytterbium (Yb), an atomic percentage of Yb in the AlN being greater than or equal to approximately 10.0% and less than or equal to approximately 27.0%. Piezoelectric layers comprising the piezoelectric material may be used in bulk acoustic wave (BAW) acoustic resonators, and surface acoustic wave (SAW) acoustic resonators. The BAW acoustic resonators and SAW acoustic resonators can be used in a variety of applications.

Abstract: To easily form an ultrasonic probe and an ultrasonic inspection apparatus capable of sending ultrasonic waves having frequencies equal to or more than 200 MHz. In view of this, an ultrasonic probe includes a stacked piezoelectric element configuring an ultrasonic probe includes a stacked piezoelectric element in which a stacked piezoelectric film disposed between a lower electrode and an upper electrode. The stacked piezoelectric film includes a ZnO film that has spontaneous polarization in a direction substantially perpendicular to the film surface and a SLAIN film that is different from the ZnO and that has spontaneous polarization in the opposite direction to the ZnO, the SLAIN film being directly formed on the ZnO film.

Abstract: The present invention is made to provide a method of producing a ZnO thin film in which the c-axis is oriented in-plane over a large area. A ZnO target 28 as the material of the thin film is sputtered by using a magnetron sputtering system, and a flow of material (material flow) directed from the cathode 23 to the anode 24 is generated in a plasma. The material flow has a high density at its central part and has a low density as it departs from the central part. A substrate 20 is fixed at a position displaced from the central axis of a region 30 where the material flow is generated so as to be inclined relative to the central axis. Thereby, a temperature gradient is naturally formed on the substrate 20, and the c-axis of the ZnO thin film deposited on the substrate 20 is oriented in-plane to the temperature gradient direction. Since the substrate 20 is fixed so as to be inclined relative to the material flow, the area where the c-axis is consistently oriented in-plane becomes larger than before.

Abstract: A magnetron circuit of a rectangular type is disposed on a lower surface of a rectangular target. A half of the target is covered with a shield plate, so that sputtering particles sputtered from an erosion region (a region with a maximized magnetic flux density) therebelow is blocked so as not to fly toward a substrate. The substrate is disposed at a level so as to be located in a plasma region of a vacuum chamber, and sputtering particles (ZnO) sputtered from a region exposed from the shield plate in the erosion region is caused to be incident on a surface of the substrate. When a gas pressure is lowered, a mean free path of each of the sputtering particles is lengthened to cause a large amount of high-energy sputtering particles to be incident. As a result, a hexagonal crystal particle having a plane that is a crystal plane hardly damaged by incidence of the high-energy sputtering particles is preferentially grown to form a c-axis in-plane oriented film.

Abstract: The present invention is made to provide a method of producing a ZnO thin film in which the c-axis is oriented in-plane over a large area. A ZnO target 28 as the material of the thin film is sputtered by using a magnetron sputtering system, and a flow of material (material flow) directed from the cathode 23 to the anode 24 is generated in a plasma. The material flow has a high density at its central part and has a low density as it departs from the central part. A substrate 20 is fixed at a position displaced from the central axis of a region 30 where the material flow is generated so as to be inclined relative to the central axis. Thereby, a temperature gradient is naturally formed on the substrate 20, and the c-axis of the ZnO thin film deposited on the substrate 20 is oriented in-plane to the temperature gradient direction. Since the substrate 20 is fixed so as to be inclined relative to the material flow, the area where the c-axis is consistently oriented in-plane becomes larger than before.