A composite substrate of the present disclosure includes a piezoelectric substrate having a first surface which is an element formation surface and a second surface which is a back surface of the first surface, a sapphire substrate having a third surface which is disposed opposing a second surface and a fourth surface which is a back surface of the third surface, a fifth surface opposing the second surface, and a sixth surface opposing the third surface. It includes an alumina layer bonding the second surface and the third surface, and an arithmetic mean roughness Ra of the third surface is 0.1 ?m or more and 0.5 ?m or less. The arithmetic mean roughness Ra of the fifth surface is 0.1 ?m or less and is smaller than the arithmetic mean roughness Ra of the third surface.

An acoustic resonator device with low thermal impedance has a substrate and a single-crystal piezoelectric plate having a back surface attached to a top surface of the substrate via a bonding oxide (BOX) layer. An interdigital transducer (IDT) formed on the front surface of the plate has interleaved fingers disposed on the diaphragm, the overlapping distance of the interleaved fingers defining an aperture of the resonator device. Contact pads are formed at selected locations over the surface of the substrate to provide electrical connections between the IDT and contact bumps to be attached to the contact pads. The piezoelectric plate is removed from at least a portion of the surface area of the device beneath each of the contact pads to provide lower thermal resistance between the contact bumps and the substrate.

A piezoelectric element application device according to the disclosure includes: a vibration plate made of silicon oxide; a first electrode formed above the vibration plate; a seed layer formed above the first electrode and the vibration plate; a piezoelectric layer formed at the seed layer and containing potassium, sodium, and niobium; and a second electrode formed at the piezoelectric layer. The vibration plate further contains potassium and sodium. In secondary ion mass spectrometry on the vibration plate and the piezoelectric layer, an intensity of potassium in the vibration plate is lower than an intensity of potassium in the piezoelectric layer, and an intensity of sodium in the vibration plate is lower than an intensity of sodium in the piezoelectric layer.

A piezoelectric substrate according to an aspect of the present disclosure comprising: a substrate including a first region and a second region; a first electrode layer formed above the substrate; a seed layer formed in the first region above the substrate; and a piezoelectric layer formed in the first region and the second region above the substrate and containing potassium, sodium, and niobium, wherein the substrate includes a plurality of centers of curvature.

Disclosed are a piezoelectric sensor and a driving method therefor, and a haptic feedback apparatus. The piezoelectric sensor includes: a substrate, and a first electrode laver, a piezoelectric film laver and a second electrode laver that are located on the substrate, where the first electrode laver is grounded, and the second electrode laver is coupled to a driving signal end. The driving method includes: loading a grounding signal to the first electrode laver, and loading a driving signal on which a direct current voltage and an alternating current voltage are superimposed to the second electrode layer.

Layer structures for RF filters can be fabricated using rare earth oxides and epitaxial aluminum nitride, and methods for growing the layer structures. A layer structure can include an epitaxial crystalline rare earth oxide (REO) layer over a substrate, a first epitaxial electrode layer over the crystalline REO layer, and an epitaxial piezoelectric layer over the first epitaxial electrode layer. The layer structure can further include a second electrode layer over the epitaxial piezoelectric layer. The first electrode layer can include an epitaxial metal. The epitaxial metal can be single-crystal. The first electrode layer can include one or more of a rare earth pnictide, and a rare earth silicide (RESi).

The invention relates to a layer having piezoelectric properties and a method for producing a layer having piezoelectric properties, in particular by means of aerosol deposition method (ADM).

The present invention relates to a piezoelectric sensor manufacturing method, and the piezoelectric sensor manufacturing method according to the present invention includes the steps of: forming a mold in the form of a sensor array pattern including a plurality of grooves by etching a semiconductor substrate; injecting and sintering a piezoelectric material in the grooves; forming piezoelectric rods in the form of a sensor array pattern by etching the semiconductor substrate to protrude the piezoelectric material, i.e., etching to protrude a first area at one side of the pattern; forming an insulation layer by filling an insulation material in the semiconductor substrate; flattening the insulation layer until the piezoelectric material is exposed; forming a first electrode on a first surface of the piezoelectric material and the insulation layer; bonding a dummy substrate on the semiconductor substrate on which the first electrode is formed; flattening a second surface of the semiconductor substrate until the piezoelectric material is exposed; forming a second electrode on a second surface of the piezoelectric material; and exposing the first electrode by etching the first area.

A piezoelectric element having a vibrating section including a vibrating plate, a first electrode, a piezoelectric layer, and a second electrode, in which a crystal orientation of a piezoelectric material forming the piezoelectric layer is (100) and a crystal structure of the piezoelectric material is a tetragonal crystal, and a total thickness T.sub.1 of the vibrating plate and the first electrode and a total thickness T.sub.2 of the piezoelectric layer and the second electrode have a relationship of T.sub.1?T.sub.2.

An inkjet printing head 1 includes a piezoelectric element 6 having a lower electrode 7, a piezoelectric film 8 formed above the lower electrode 7, and an upper electrode 9 formed above the piezoelectric film 8, a hydrogen barrier film 13 covering an entirety of a side surface of the upper electrode 9 and the piezoelectric film 8, and an interlayer insulating film 14 that has an opening 17 at an upper surface center of the upper electrode 9, is laminated on the hydrogen barrier film 13, and faces the entirety of the side surface of the upper electrode 9 and the piezoelectric film 8 across the hydrogen barrier film 13.