Abstract: A thin film piezoelectric resonator includes a substrate having a cavity; a first electrode extending over the cavity; a piezoelectric film placed on the first electrode; and a second electrode placed on the piezoelectric film, the second electrode having a periphery partially overlapping on the cavity and tapered to have an inner angle of 30 degrees or smaller defined by a part of the periphery thereof and a bottom thereof.

Abstract: A piezoelectric device which is a MEMS device is provided. In the device, the entire silicon layer of the SOI substrate is a p-type region. A plurality of n-type regions are formed in the silicon layer so as to be exposed to the upper surface of the silicon layer and spaced from each other. A piezoelectric film made of AlN is provided on the SOI substrate so as to contact the n-type region, and a conductor film made of aluminum is provided on the piezoelectric film. Thereby, the n-type region functions as a lower electrode and the conductor film functions as an upper electrode.

Abstract: A thin-film piezoelectric resonator includes a substrate, and first and second excitation portions. The substrate includes first and second cavities. The first excitation portion is disposed over the first cavity, and includes a first electrode, a first piezoelectric material and a second electrode laminated successively. An overlapping region among the first electrode, the first piezoelectric material and the second electrode defines a contour of a periphery of the first excitation portion. A first distance is defined as a distance from an end of the first excitation portion to an opening end of the first cavity. The second excitation portion is disposed over the second cavity, and includes a third electrode, a second piezoelectric material and a fourth electrode laminated successively. A second distance is defined as a distance from an end of the second excitation portion to an opening end of the second cavity and different from the first distance.

Abstract: A piezoelectric thin film resonator includes a substrate in which a cavity is formed, a first electrode having a first electrode edge and partly spanning the cavity on the substrate; a piezoelectric layer placed on the first electrode, a second electrode having a second electrode edge and placed on the piezoelectric layer, a resonator unit constituted by an overlapping part of the first electrode, the piezoelectric layer, the second electrode, and the cavity; and a second lead wiring which is integral with the second electrode, extends to the substrate where the cavity is not present, and has a width larger than a part of a peripheral length of the cavity to which the second electrode edge extends. In the piezoelectric thin film resonator, a first length defined by the periphery of the first electrode of the resonator unit is larger than a second length defined by the second electrode edge of the resonator unit.

Abstract: A thin film piezoelectric resonator includes a substrate having a cavity; a first electrode extending over the cavity; a piezoelectric film placed on the first electrode; and a second electrode placed on the piezoelectric film, the second electrode having a periphery partially overlapping on the cavity and tapered to have an inner angle of 30 degrees or smaller defined by a part of the periphery thereof and a bottom thereof.

Abstract: A film bulk acoustic-wave resonator encompasses a substrate having a cavity; a bottom electrode partially fixed to the substrate, part of the bottom electrode is mechanically suspended above the cavity; a piezoelectric layer provided on the bottom electrode; and a top electrode provided on the piezoelectric layer having crystal axes oriented along a thickness direction of the piezoelectric layer, a full width at half maximum of the distribution of the orientations of the crystal axes is smaller than or equal to about six degrees.

Abstract: A piezoelectric thin film device includes an amorphous metal film disposed on a substrate and a piezoelectric film disposed on the amorphous metal. One of crystal axis of the piezoelectric film is aligned in a direction perpendicular to a surface of the amorphous metal.

Abstract: A piezoelectric thin film device includes an amorphous metal film disposed on a substrate and a piezoelectric film disposed on the amorphous metal. One of crystal axis of the piezoelectric film is aligned in a direction perpendicular to a surface of the amorphous metal.

Abstract: A piezoelectric thin film device includes an amorphous metal film disposed on a substrate and a piezoelectric film disposed on the amorphous metal. One of crystal axis of the piezoelectric film is aligned in a direction perpendicular to a surface of the amorphous metal.

Abstract: A piezoelectric thin film device includes an amorphous metal film disposed on a substrate and a piezoelectric film disposed on the amorphous metal. One of crystal axis of the piezoelectric film is aligned in a direction perpendicular to a surface of the amorphous metal.

Abstract: An electronic device includes: a lower electrode; a first piezoelectric film provided on the lower electrode; and an upper electrode provided on the first piezoelectric film. At least one of the lower electrode and the upper electrode is made of an alloy composed primarily of aluminum and doped with at least one element selected from the group consisting of Ni, Co, V, Ta, Mo, W, Ti, Y, and Nd. Alternatively, an electronic device includes: a support substrate; a lower electrode provided on the support substrate; a first piezoelectric film provided on the lower electrode; and an upper electrode provided on the first piezoelectric film. The lower electrode is made of an alloy composed primarily of aluminum and doped with at least one element selected from the group consisting of Ni, Co, V, Ta, Mo, W, Ti, Y, and Nd.

Abstract: An electronic device includes: a substrate; a first film provided on a major surface of the substrate; and a crystalline second film covering at least a part of the end surface and provided on the first film and the substrate. The end surface has an inclined surface which is inclined to the major surface of the substrate. The inclined surface has a curved surface whose slope becomes gentle with getting closer to the substrate.

Abstract: A film bulk acoustic-wave resonator having, a substrate having a cavity, the substrate being formed of one of semi-insulating material and high-resistivity material, a bottom electrode partially fixed to the substrate, part of the bottom electrode is mechanically suspended above the cavity, a piezoelectric layer disposed on the bottom electrode, the shape of the piezoelectric layer is defined by a contour, a top electrode on the piezoelectric layer, a semiconductor intermediate electrode buried at and in a surface of the substrate, being located at the contour of the piezoelectric layer, the semiconductor region having a lower resistivity than the substrate, the intermediate electrode is connected to the bottom electrode in the inside of the contour, and a bottom electrode wiring connected to the semiconductor intermediate electrode extending from the contour to an outside of the contour in the plan view.

Abstract: A film bulk acoustic resonator includes: a support substrate; and a laminated body provided on the support substrate, a portion of the laminated body being supported by the support substrate and another portion of the laminated body being spaced from the support substrate. The laminated body includes: a first electrode primarily composed of aluminum; a piezoelectric film laminated on the first electrode and primarily composed of aluminum nitride; and a second electrode laminated on the piezoelectric film. The second electrode is primarily composed of a metal having a density of 1.9 or more times the density of aluminum.

Abstract: It is possible to provide a resonator structure that does not cause a variation in anti-resonant frequency can be achieved, even if the cavity and the upper and lower electrode shift. A thin-film piezoelectric resonator includes: a lower electrode provided on the principal surface of the substrate so as to cover the cavity; a piezoelectric film provided on the lower electrode so as to be located above the cavity; and an upper electrode. The upper electrode includes: a main portion which overlaps a part of the cavity, a protruding portion connected to the main portion, an extension portion provided at the opposite side of the main portion. The length of the protruding portion in a direction perpendicular to a direction of connecting to the main portion is substantially the same as the length of the connecting portion in a direction perpendicular to a direction of connecting to the main portion.

Abstract: A film bulk acoustic-wave resonator having, a substrate having a cavity, the substrate being formed of one of semi-insulating material and high-resistivity material, a bottom electrode partially fixed to the substrate, part of the bottom electrode is mechanically suspended above the cavity, a piezoelectric layer disposed on the bottom electrode, the shape of the piezoelectric layer is defined by a contour, a top electrode on the piezoelectric layer, a semiconductor intermediate electrode buried at and in a surface of the substrate, being located at the contour of the piezoelectric layer, the semiconductor region having a lower resistivity than the substrate, the intermediate electrode is connected to the bottom electrode in the inside of the contour, and a bottom electrode wiring connected to the semiconductor intermediate electrode extending from the contour to an outside of the contour in the plan view.

Abstract: A voltage controlled oscillator includes a resonator configured to resonate with an initial oscillation frequency during starting period of oscillation and a steady oscillation frequency during a steady state oscillation. The resonator includes a film bulk acoustic resonator having a series resonance frequency higher than the steady oscillation frequency. A negative resistance circuit configured to drive the resonator, has a positive increment for reactance in the steady state oscillation compared with reactance in the starting period.

Abstract: A circuit board includes a substrate, a nonconductive resin layer selectively formed on the substrate and containing fine metal particles, and a conductive metal layer formed on the resin layer, in contact with the fine metal particles which are exposed from the resin layer. A surface of the resin layer has irregularities, in an interface between the resin layer and the conductive metal layer. In a roughness curve of a section of the resin layer, in a case of an wavelength (?c) at the boundary of a roughness component and a waviness component is 1 ?m, a maximum height (Rz) per reference length (1r) of 1 ?m is 20 nm to 500 nm.

Abstract: A film bulk acoustic-wave resonator encompasses (a) a substrate having a cavity, (b) a bottom electrode partially fixed to the substrate, part of the bottom electrode is mechanically suspended above the cavity, (c) a piezoelectric layer disposed on the bottom electrode, a planar shape of the piezoelectric layer is defined by a contour, which covers an entire surface of the bottom electrode in a plan view, (d) a top electrode on the piezoelectric layer, (e) an intermediate electrode located between the substrate and the piezoelectric layer, and at the contour of the piezoelectric layer, the intermediate electrode is connected to the bottom electrode in the inside of the contour, and (f) a bottom electrode wiring connected to the intermediate electrode extending from the contour to an outside of the contour in the plan view, wherein a longitudinal vibration mode along a thickness direction of the piezoelectric layer is utilized.

Abstract: A piezoelectric thin film resonator includes a substrate in which a cavity is formed, a first electrode having a first electrode edge and partly spanning the cavity on the substrate; a piezoelectric layer placed on the first electrode, a second electrode having a second electrode edge and placed on the piezoelectric layer, a resonator unit constituted by an overlapping part of the first electrode, the piezoelectric layer, the second electrode, and the cavity; and a second lead wiring which is integral with the second electrode, extends to the substrate where the cavity is not present, and has a width larger than a part of a peripheral length of the cavity to which the second electrode edge extends. In the piezoelectric thin film resonator, a first length defined by the periphery of the first electrode of the resonator unit is larger than a second length defined by the second electrode edge of the resonator unit.