According to one embodiment, a method of manufacturing a piezoelectric element, includes forming lower electrodes on an insulating substrate, applying a precursor solution on the insulating substrate and the lower electrodes, drying the precursor solution by firing, thus forming a first precursor layer, patterning the first precursor layer into a shape of a plurality of islands located on the lower electrodes, respectively and crystallizing the island-shaped first precursor layer by firing, thus forming first piezoelectric layers.

Examples disclosed herein relate to an apparatus and method of forming thin film layers on a substrate. A first piezoelectric material layer is deposited on the substrate in a first chamber. The first piezoelectric material layer is formed on the substrate while the substrate is at a first temperature. A second piezoelectric material layer is deposited on the first piezoelectric material layer after cooling the substrate to a second temperature. The second temperature is lower than the first temperature. The first piezoelectric material layer and the second piezoelectric material layer both comprise a first piezoelectric material.

A composite substrate includes a final substrate, and a piezoelectric material directly molecularly bonded to the final substrate at a first interface. The piezoelectric material comprises an epitaxial layer, but does not comprise a seed layer. Additional composite substrates include a final substrate, and a piezoelectric material directly molecularly bonded to the final substrate at a first interface. The piezoelectric material comprises an epitaxial layer. The composite substrate further includes a seed layer on which the piezoelectric material has been epitaxially grown. The seed layer is disposed on a side of the epitaxial layer opposite the final substrate. An acoustic wave device comprises such a composite substrate with at least one electrode on a surface of the piezoelectric layer opposite the substrate.

The vibration apparatus may include a vibration generating portion including a first vibration portion and a second vibration portion overlapping the first vibration portion, a first cover member at a first surface of the vibration generating portion, a second cover member at a second surface different from the first surface of the vibration generating portion, and a signal cable including first, second and third signal lines connected to the first vibration portion and the second vibration portion and disposed between the first cover member and the second cover member. An apparatus for vibration may include a passive vibration member and the vibration apparatus.

A piezoelectric device has a layered structure in which at least a first electrode, a plastic layer, an orientation control layer, a piezoelectric layer, and a second electrode are stacked, wherein the orientation control layer is amorphous, and the piezoelectric layer with a thickness of 20 nm to 250 nm is provided over the orientation control layer, the piezoelectric layer having a wurtzite crystal structure, and wherein the orientation control layer and the piezoelectric layer are provided between the first electrode and the second electrode.

A vibration apparatus may include a vibration device and an adhesive member at a surface of the vibration device. A modulus of the vibration device may be equal to a modulus of the adhesive member or may be greater than the modulus of the adhesive member.

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 bulk acoustic wave resonator includes a substrate, and a stack that is supported by the substrate. The stack includes a first electrode, a multilayer buffer, a piezoelectric layer, and a second electrode. The multilayer buffer is disposed between the first electrode and the piezoelectric layer, and the piezoelectric layer is disposed between the multilayer buffer and the second electrode. The multilayer buffer includes two or more pairs of alternating layers. A first pair of the two or more pairs include a first layer of crystalline material having a first lattice constant, and a second layer of crystalline material having a lattice constant that is distinct from the first lattice constant.

A bulk-acoustic wave (BAVV) resonator is provided. The BAW includes a substrate, a first electrode disposed on the substrate, a piezoelectric layer disposed to cover at least a portion of the first electrode, and a second electrode disposed to cover at least a portion of the piezoelectric layer, wherein the piezoelectric layer includes an intermediate layer, a first layer disposed above the intermediate layer and a second layer disposed below the intermediate layer, the first layer and the second layer are symmetrical in relation to a plane through which a central line of the intermediate layer passes in a thickness direction, and a thickness of the intermediate layer is greater than a thickness of each of the first and second layers.

A piezoelectric thin film 3 contains a metal oxide, the metal oxide contains bismuth, potassium, titanium, iron and element M, the element M is at least one of magnesium and nickel, at least a part of the metal oxide is a crystal having a perovskite structure, and a (001) plane, a (110) plane or a (111) plane of the crystal is oriented in a normal direction dn of the surface of the piezoelectric thin film 3.