The disclosure relates to a hybrid structure for a surface-acoustic-wave device comprising a useful layer of piezoelectric material joined to a carrier substrate having a thermal expansion coefficient lower than that of the useful layer; the hybrid structure comprising an intermediate layer located between the useful layer and the carrier substrate, the intermediate layer being a structured layer formed from at least two different materials comprising a plurality of periodic motifs in the plane of the intermediate layer.

Acoustic resonator devices and filters are disclosed. An acoustic resonator includes a substrate having a trap-rich region adjacent to a surface and a single-crystal piezoelectric plate having parallel front and back surfaces, the back surface attached to the surface of the substrate except for a portion of the piezoelectric plate forming a diaphragm that spans a cavity in the substrate. An interdigital transducer (IDT) is formed on the front surface of the single-crystal piezoelectric plate such that interleaved fingers of the IDT are disposed on the diaphragm. The single-crystal piezoelectric plate and the IDT are configured such that a radio frequency signal applied to the IDT excites a shear primary acoustic mode within the diaphragm.

A piezoelectric device includes a piezoelectric vibrating piece and a container. The piezoelectric vibrating piece has a rectangular planar shape and has a portion of a first side secured to the container. The piezoelectric vibrating piece has a second side opposing the first side and includes a projecting portion that projects outward from the second side in at least one of proximity of both ends of the second side along the second side.

In one example, a method of forming a bulk acoustic wave (BAW) resonator comprises: forming an electrode on at least one of a semiconductor substrate, a sacrificial layer, or an acoustic reflector; and forming a piezoelectric layer on the electrode, the piezoelectric layer having a convex surface.

A method of manufacturing a vibrator element having a vibrating part which vibrates in a thickness-shear mode, and a thin-wall part which is coupled to the vibrating part, and which is thinner than the vibrating part includes a preparation step of preparing a quartz crystal substrate, a resist film formation step of forming a resist film in a vibrating part area of the quartz crystal substrate where the vibrating part is formed, an etching step of etching the quartz crystal substrate via the resist film, then ending the etching in a state in which the resist film remains in the vibrating part area to thereby form the vibrating part and the thin-wall part, and a resist film removal step of removing the resist film remaining.

A film bulk acoustic wave resonator includes a piezoelectric film disposed over a cavity. The cavity is shaped as partial ellipse including first, second, and third vertices. The film bulk acoustic wave resonator further includes three release ports in positions that minimize etch time to remove all sacrificial material from within the cavity.

Methods of fabricating acoustic filters are disclosed. The back of a piezoelectric plate is bonded to a surface of a substrate. The thickness of the piezoelectric plate is measured at a plurality of positions. Excess material is removed from the front surface of the piezoelectric plate in accordance with the thickness measurements to improve the thickness uniformity of the piezoelectric plate. After removing the excess material, a conductor pattern including a plurality of ladder filter circuits is formed on the front surface. Each ladder filter circuit includes at least one shunt resonator and at least one series resonator, each of which has an interdigital transducer (IDT). Cavities are formed in the substrate such that portions of the piezoelectric plate form a plurality of diaphragms spanning respective cavities. After the cavities are formed, interleaved fingers of each IDT are on a respective one of the plurality of diaphragms.

Sputter depositing a metallic layer on a substrate in the fabrication of a resonator device includes providing a magnetron sputtering apparatus comprising a chamber, a substrate support disposed within the chamber, a target made from a metallic material, and a plasma generating device, wherein the substrate support and the target are separated by a distance of 10 cm or less; supporting the substrate on the substrate support; performing a DC magnetron sputtering step that comprises sputtering the metallic material from the target onto the substrate so as to form a metallic layer on the substrate, wherein during the DC magnetron sputtering step the chamber has a pressure of at least 6 mTorr of a noble gas, the target is supplied with a power having a power density of at least 6 W/cm.sup.2, and the substrate has a temperature in the range of 200-600° C.

A bulk acoustic wave (BAW) filter for passing through electric signals in a preset frequency range is provided. The BAW filter includes: a diamond substrate; a passivation layer formed on the diamond substrate; a first metal layer formed on the passivation layer; a piezoelectric layer formed on the first metal layer; a second metal layer formed on a piezoelectric layer and a metal pad formed on the first metal layer. The metal pad, first metal layer, piezoelectric layer and second metal layer form an electrical path that allows an electrical signal within a preset frequency range to pass therethrough.

Methods of fabricating acoustic resonators are disclosed. A back surface of a piezoelectric plate is bonded to a surface of a substrate. Thickness measurements are made at a plurality of positions on the piezoelectric plate. Excess material is removed from the front surface of the piezoelectric plate in accordance with the thickness measurements to improve a thickness uniformity of the piezoelectric plate. A conductor pattern is formed on the front surface, the conductor pattern including a plurality of interdigital transducers (IDTs) of a plurality of resonators. Cavities are formed in the substrate such that portions of the single-crystal piezoelectric plate form a plurality of diaphragms spanning respective cavities, wherein interleaved fingers of each IDT of the plurality of IDTs are disposed on a respective one of the plurality of diaphragms.