An aspect of the present invention relates to a vibration element comprising: a substrate; a ceramic layer containing glass and provided on the substrate; and a piezoelectric element comprising an electrode layer fixed to the substrate with the ceramic layer therebetween and a piezoelectric layer, wherein the piezoelectric layer, the electrode layer, the substrate, and the ceramic layer are integrated by the piezoelectric layer, the electrode layer, the substrate, and the ceramic layer being sintered together at a sintering temperature of from 800° C. or higher to 940° C. or lower.

A method for forming a MEMS device is provided. The method includes forming a stack of layers on a base piezoelectric layer. The stack of layers includes a base metal film over the base piezoelectric layer; a first piezoelectric film over the base metal film; and a first metal film having an opening therein over the first piezoelectric film. The method also includes forming a trench in the stack of layers, wherein the trench passes through the opening in the first metal film but does not expose the base metal film; after forming the trench, forming a spacer structure under the first metal film but spaced apart from the base metal film; after forming the spacer structure, deepening the trench to expose the base metal film; and forming a contact in the trench.

A piezoelectric device includes a first substrate that includes a piezoelectric element (32) provided in a first region where bending deformation is allowed and an electrode layer (39) electrically connected to the piezoelectric element (32), a second substrate in which a bump electrode (43) abutting and conducting the electrode layer (39), and having elasticity is formed, and which is disposed so as to face the piezoelectric element (32) with a predetermined space, and adhesive (43) that bonds the first substrate and the second substrate in a state where a distance between the first substrate and the second substrate is maintained. The adhesive (43) has a width in a center portion in a height direction relative to a surface of the first substrate or the second substrate greater than a width in end portions in the same direction.

There is provided a piezoelectric element which includes a first electrode which is formed on a substrate, a piezoelectric layer which is formed on the first electrode, and is formed from a compound oxide having an ABO.sub.3 type perovskite structure in which potassium (K), sodium (Na), niobium (Nb), and manganese (Mn) are provided, and a second electrode which is formed on the piezoelectric layer. The manganese includes bivalent manganese (Mn.sup.2+), trivalent manganese (Mn.sup.3+), and tetravalent manganese (Mn.sup.4+). A molar ratio (Mn.sup.2+/Mn.sup.3++Mn.sup.4+) of the bivalent manganese to a sum of the trivalent manganese and the tetravalent manganese is equal to or greater than 0.31.

Provided is a piezoelectric thin film device in which lattice mismatch between a piezoelectric thin film and a lower electrode layer (first electrode layer) is reduced. A piezoelectric thin film device 10 comprises a first electrode layer 6a and a piezoelectric thin film 2 laminated directly on the first electrode layer 6a; the first electrode layer 6a includes an alloy composed of two or more metal elements; the first electrode layer 6a has a face-centered cubic lattice structure; and the piezoelectric thin film 2 has a wurtzite structure.

A stacked film includes an oxide film including a ZrO.sub.2 film, a metal oxide film provided on the oxide film, and a predetermined metal film provided on the metal oxide film and having a single orientation, and the metal oxide film is a PtO film or a PdO film. In the case of this structure, the predetermined metal film has a single orientation, and characteristics of the piezoelectric film such as PZT formed on the predetermined metal film are improved. Therefore, excellent characteristics such as an increase in the driving force due to the piezoelectric film or a reduction in leakage current can be exhibited.

A piezoelectric device includes a piezoelectric vibrating piece, a base, a wire, a conductive adhesive, and a buffer layer. The piezoelectric vibrating piece includes excitation electrodes and extraction electrodes at both principal surfaces. The base includes the piezoelectric vibrating piece and a first wiring electrode and a second wiring electrode connected to the extraction electrodes. The wire connects the extraction electrode on a surface opposite to a side of the base among the extraction electrodes to one wiring electrode of the first wiring electrode and the second wiring electrode. The conductive adhesive connects the extraction electrode at the base side among the extraction electrodes to the other wiring electrode among the first wiring electrode and the second wiring electrode. The buffer layer reduces stress of the wire between the extraction electrode to which the wire is connected and the piezoelectric vibrating piece.

An ultrasound probe of the present disclosure includes an ultrasound element unit 1, to which a flexible substrate 7 is connected, the flexible substrate 7 including lamination of a ground layer 7e and a signal layer 7a via an insulation layer 7c. The flexible substrate 7 includes a bending part and a flat part. The signal layer 7a includes a linear first signal line and a linear second signal line that are adjacent to each other. The ground layer 7e at the bending part includes a linear first ground line and a linear second ground line that are adjacent to each other. The first signal line and the first ground line are opposed to each other, and the second signal line and the second ground line are opposed to each other.

A piezoelectric vibrator according to the invention has a base, an integrated circuit element, and a piezoelectric vibration element. The base has internal terminal pads, and external terminals including an AC output terminal. The base includes rectangular ceramic substrate layers stacked in at least three layers, each of which has castellations formed at four corners. Among the internal terminal pads, internal terminal pads for the integrated circuit element and internal terminal pads for the piezoelectric vibration element are connected to each other by externally exposed wiring patterns formed on upper surfaces of the castellations at the corners of the ceramic substrate constituting a middle layer.

An ultrasound vibration device is provided with a stacked transducer in which a plurality of piezoelectric single crystal element layers are stacked between two metal blocks. Since each of the two metal blocks and the plurality of piezoelectric single crystal element layers is fusion-bonded relative to a stack direction by bonding metal having a melting point corresponding to half a Curie point of the plurality of piezoelectric single crystal element layers or below, it is possible to use non-lead material, reduce a processing cost and realize inexpensiveness.