A method for adjusting a resonant frequency of a resonator without impairing piezoelectricity that includes preparing a lower lid; arranging a substrate with a lower surface that faces the lower lid and forming a first electrode layer, a piezoelectric film, and a second electrode layer on an upper surface of the substrate. Moreover, a vibration arm is formed that bends and vibrates from the first electrode layer, the second electrode layer, and the piezoelectric film and an upper lid faces the lower lid with the resonator interposed therebetween. The method further includes adjusting a frequency of the resonator before or after arranging the upper lid by exciting the vibration arm by applying a voltage between the first electrode layer and the second electrode layer and by causing a part of the vibration arm to collide with either or both of the lower lid and the upper lid.

A method for adjusting a resonant frequency of a resonator without impairing piezoelectricity that includes preparing a lower lid; arranging a substrate with a lower surface that faces the lower lid and forming a first electrode layer, a piezoelectric film, and a second electrode layer on an upper surface of the substrate. Moreover, a vibration arm is formed that bends and vibrates from the first electrode layer, the second electrode layer, and the piezoelectric film and an upper lid faces the lower lid with the resonator interposed therebetween. The method further includes adjusting a frequency of the resonator before or after arranging the upper lid by exciting the vibration arm by applying a voltage between the first electrode layer and the second electrode layer and by causing a part of the vibration arm to collide with either or both of the lower lid and the upper lid.

Provided are a piezoelectric resonator and a manufacturing method of the piezoelectric resonator. The piezoelectric resonator includes a substrate, a recess is formed on an upper surface of the substrate; a first piezoelectricity layer covering the upper surface of the substrate and an opening of the recess to enable the recess and the first piezoelectricity layer to form a cavity; a first electrode and a temperature compensation layer, which are both disposed on a side of the first piezoelectricity layer facing away from the substrate, in a direction perpendicular to the substrate, a projection of the first electrode on the substrate is located at an area in which the recess is located.

Provided are a piezoelectric resonator and a manufacturing method of the piezoelectric resonator. The piezoelectric resonator includes a substrate, a recess is formed on an upper surface of the substrate; a first piezoelectricity layer covering the upper surface of the substrate and an opening of the recess to enable the recess and the first piezoelectricity layer to form a cavity; a first electrode and a temperature compensation layer, which are both disposed on a side of the first piezoelectricity layer facing away from the substrate, in a direction perpendicular to the substrate, a projection of the first electrode on the substrate is located at an area in which the recess is located.

An elastic wave device includes a supporting substrate, a high-acoustic-velocity film stacked on the supporting substrate and in which an acoustic velocity of a bulk wave propagating therein is higher than an acoustic velocity of an elastic wave propagating in a piezoelectric film, a low-acoustic-velocity film stacked on the high-acoustic-velocity film and in which an acoustic velocity of a bulk wave propagating therein is lower than an acoustic velocity of a bulk wave propagating in the piezoelectric film, the piezoelectric film is stacked on the low-acoustic-velocity film, and an IDT electrode stacked on a surface of the piezoelectric film.

An elastic wave device includes a supporting substrate, a high-acoustic-velocity film stacked on the supporting substrate and in which an acoustic velocity of a bulk wave propagating therein is higher than an acoustic velocity of an elastic wave propagating in a piezoelectric film, a low-acoustic-velocity film stacked on the high-acoustic-velocity film and in which an acoustic velocity of a bulk wave propagating therein is lower than an acoustic velocity of a bulk wave propagating in the piezoelectric film, the piezoelectric film is stacked on the low-acoustic-velocity film, and an IDT electrode stacked on a surface of the piezoelectric film.

Acoustic filters, resonators and methods are disclosed. An acoustic filter device includes a substrate having a surface and a single-crystal piezoelectric plate having front and back surfaces and a thickness ts, the back surface attached to the surface of the substrate except for portions of the piezoelectric plate forming a plurality of diaphragms that span respective cavities in the substrate. A conductor pattern is formed on the front surface of the piezoelectric plate, the conductor pattern comprising a plurality of interdigital transducers (IDTs) of a plurality of acoustic resonators, interleaved fingers of each IDT of the plurality of IDTs disposed on a respective diaphragm of the plurality of diaphragms. Zero or more dielectric layers are deposited over all of the IDTs and the diaphragms, wherein a total thickness of the zero or more dielectric layers is the same for all of the plurality of acoustic resonators.

Acoustic filters, resonators and methods are disclosed. An acoustic filter device includes a substrate having a surface and a single-crystal piezoelectric plate having front and back surfaces and a thickness ts, the back surface attached to the surface of the substrate except for portions of the piezoelectric plate forming a plurality of diaphragms that span respective cavities in the substrate. A conductor pattern is formed on the front surface of the piezoelectric plate, the conductor pattern comprising a plurality of interdigital transducers (IDTs) of a plurality of acoustic resonators, interleaved fingers of each IDT of the plurality of IDTs disposed on a respective diaphragm of the plurality of diaphragms. Zero or more dielectric layers are deposited over all of the IDTs and the diaphragms, wherein a total thickness of the zero or more dielectric layers is the same for all of the plurality of acoustic resonators.

Acoustic filters, resonators and methods are disclosed. An acoustic resonator device includes a substrate having a surface. A back surface of a single-crystal piezoelectric plate is 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. A conductor pattern is formed on the front surface of the piezoelectric plate, the conductor pattern including an interdigital transducer (IDTs), interleaved fingers of the IDT disposed on the diaphragm. A pitch of the interleaved fingers and a mark of the interleaved fingers are set in combination such that a resonance frequency of the acoustic resonator is equal to a predetermined target frequency.

Acoustic filters, resonators and methods are disclosed. An acoustic resonator device includes a substrate having a surface. A back surface of a single-crystal piezoelectric plate is 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. A conductor pattern is formed on the front surface of the piezoelectric plate, the conductor pattern including an interdigital transducer (IDTs), interleaved fingers of the IDT disposed on the diaphragm. A pitch of the interleaved fingers and a mark of the interleaved fingers are set in combination such that a resonance frequency of the acoustic resonator is equal to a predetermined target frequency.