An acoustic wave element which can be reduced in size and produced relatively easily, practically used without using harmful substances, and can suppress a surface acoustic wave propagation loss, which has an excellent temperature coefficient of frequency and a velocity dispersion characteristic, and with which an increase in the reflection coefficient of interdigital transducers can be suppressed, and a method for manufacturing the acoustic wave element are provided. The acoustic wave element includes a pair of electrodes provided on both surfaces of a piezoelectric substrate, and a dielectric film provided on a first surface of the piezoelectric substrate so as to cover the electrode. The acoustic wave element alternatively includes interdigital transducers provided on a first surface of the piezoelectric substrate, and a dielectric film provided on the interdigital transducers, a gap between the interdigital transducers, and/or a second surface of the piezoelectric substrate.

An acoustic wave element which can be reduced in size and produced relatively easily, practically used without using harmful substances, and can suppress a surface acoustic wave propagation loss, which has an excellent temperature coefficient of frequency and a velocity dispersion characteristic, and with which an increase in the reflection coefficient of interdigital transducers can be suppressed, and a method for manufacturing the acoustic wave element are provided. The acoustic wave element includes a pair of electrodes provided on both surfaces of a piezoelectric substrate, and a dielectric film provided on a first surface of the piezoelectric substrate so as to cover the electrode. The acoustic wave element alternatively includes interdigital transducers provided on a first surface of the piezoelectric substrate, and a dielectric film provided on the interdigital transducers, a gap between the interdigital transducers, and/or a second surface of the piezoelectric substrate.

Methods of fabricating acoustic filters. A back-side frequency setting layer is formed on a surface of a substrate and/or a back surface of a piezoelectric plate. The piezoelectric plate is attached to the substrate with the back-side frequency setting layer sandwiched between the substrate and the piezoelectric plate. Portions of the piezoelectric plate and backside frequency setting layer form diaphragms spanning respective cavities in the substrate. A conductor pattern defining a plurality of acoustic resonators is formed on a front surface of the piezoelectric plate. Each of the acoustic resonators includes an interdigital transducer (IDT) with interleaved fingers disposed on a respective diaphragm. A front-side frequency setting layer is formed over the interleaved fingers and the front surface of the diaphragms of one or more shunt resonators. The back-side frequency setting layer is removed from the back surfaces of the diaphragms of one or more series resonators.

Methods of fabricating acoustic filters. A back-side frequency setting layer is formed on a surface of a substrate and/or a back surface of a piezoelectric plate. The piezoelectric plate is attached to the substrate with the back-side frequency setting layer sandwiched between the substrate and the piezoelectric plate. Portions of the piezoelectric plate and backside frequency setting layer form diaphragms spanning respective cavities in the substrate. A conductor pattern defining a plurality of acoustic resonators is formed on a front surface of the piezoelectric plate. Each of the acoustic resonators includes an interdigital transducer (IDT) with interleaved fingers disposed on a respective diaphragm. A front-side frequency setting layer is formed over the interleaved fingers and the front surface of the diaphragms of one or more shunt resonators. The back-side frequency setting layer is removed from the back surfaces of the diaphragms of one or more series resonators.

In examples, a device comprises a semiconductor die, a thin-film layer, and an air cavity positioned between the semiconductor die and the thin-film layer. The air cavity comprises a resonator positioned on the semiconductor die. A rib couples to a surface of the thin-film layer opposite the air cavity.

In examples, a device comprises a semiconductor die, a thin-film layer, and an air cavity positioned between the semiconductor die and the thin-film layer. The air cavity comprises a resonator positioned on the semiconductor die. A rib couples to a surface of the thin-film layer opposite the air cavity.

A vibrator device includes a vibrator having a first and second electrode, and a circuit device having a drive circuit adapted to drive the vibrator, and an output circuit adapted to output a monitor signal corresponding to a vibration characteristic of the vibrator while driven by the drive circuit. The circuit device includes a first terminal electrically connected to the first electrode, and from which an output signal from the drive circuit to the vibrator is output, a second terminal electrically connected to the second electrode, and to which an input signal from the vibrator to the drive circuit is input, a third terminal electrically separated from the first electrode and the second electrode, and a monitor terminal from which the monitor signal is output. The vibrator is supported on an active surface side of the circuit device using conductive bumps respectively to the first, second, and third terminal.

A vibrator device includes a vibrator having a first and second electrode, and a circuit device having a drive circuit adapted to drive the vibrator, and an output circuit adapted to output a monitor signal corresponding to a vibration characteristic of the vibrator while driven by the drive circuit. The circuit device includes a first terminal electrically connected to the first electrode, and from which an output signal from the drive circuit to the vibrator is output, a second terminal electrically connected to the second electrode, and to which an input signal from the vibrator to the drive circuit is input, a third terminal electrically separated from the first electrode and the second electrode, and a monitor terminal from which the monitor signal is output. The vibrator is supported on an active surface side of the circuit device using conductive bumps respectively to the first, second, and third terminal.

A filter device is provided that includes a substrate and a piezoelectric plate attached to the substrate. A conductor pattern is formed at a first surface of the piezoelectric plate and includes interdigital transducers of series and shunt resonators that each have interleaved fingers at respective diaphragms of the plate suspended. A first dielectric coating layer is formed over the interleaved fingers of the IDTs and on the first surface of the piezoelectric plate; and a second dielectric coating layer is formed on the second surface of the piezoelectric plate that is opposite the first surface. The second dielectric coating layer of the shunt resonator has a greater thickness than a thickness of the at least one second dielectric coating layer of the series resonator.

A filter device is provided that includes a substrate and a piezoelectric plate attached to the substrate. A conductor pattern is formed at a first surface of the piezoelectric plate and includes interdigital transducers of series and shunt resonators that each have interleaved fingers at respective diaphragms of the plate suspended. A first dielectric coating layer is formed over the interleaved fingers of the IDTs and on the first surface of the piezoelectric plate; and a second dielectric coating layer is formed on the second surface of the piezoelectric plate that is opposite the first surface. The second dielectric coating layer of the shunt resonator has a greater thickness than a thickness of the at least one second dielectric coating layer of the series resonator.