A resonator is provided that suppresses vibration of a retainer caused by undesired vibration of a vibrating portion and also achieves size reduction. Specifically, the resonator includes a vibrating member that includes a semiconductor layer, a first piezoelectric film formed on the semiconductor layer, and a first upper electrode formed on the first piezoelectric film. Moreover, a retainer is provided to retain the vibrating member such that the vibrating portion can vibrate and one or more coupling members are provided to couple the vibrating member to the retainer. Finally, the resonator includes a vibration suppressing member that includes a second piezoelectric film formed on the retainer and a second upper electrode formed on the second piezoelectric film.

A method of manufacture and structure for an acoustic resonator device having a hybrid piezoelectric stack with a strained single crystal layer and a thermally-treated polycrystalline layer. The method can include forming a strained single crystal piezoelectric layer overlying the nucleation layer and having a strain condition and piezoelectric layer parameters, wherein the strain condition is modulated by nucleation growth parameters and piezoelectric layer parameters to improve one or more piezoelectric properties of the strained single crystal piezoelectric layer. Further, the method can include forming a polycrystalline piezoelectric layer overlying the strained single crystal piezoelectric layer, and performing a thermal treatment on the polycrystalline piezoelectric layer to form a recrystallized polycrystalline piezoelectric layer. The resulting device with this hybrid piezoelectric stack exhibits improved electromechanical coupling and wide bandwidth performance.

An acoustic wave resonator includes a substrate; a resonating part disposed on a first surface of the substrate and including a first electrode, a piezoelectric layer, and a second electrode; and a cap disposed on the first surface of the substrate and including an accommodating part accommodating the resonating part. The resonating part is configured to be operated by either one or both of a signal output from a first device substrate disposed facing a second surface of the substrate on an opposite side of the substrate from the first surface of the substrate and a signal output from a second device substrate disposed on the cap.

Certain aspects of the present disclosure provide a filter circuit and techniques for filtering using the filter circuit. The filter circuit generally includes a first filter stage having a first acoustic wave resonator coupled in a series path between a first port of the filter circuit and a second port of the filter circuit, a first inductor-capacitor (LC) tank circuit, a first capacitor coupled between a first terminal of the first acoustic wave resonator and the first LC tank circuit, the first LC tank circuit being coupled between the first capacitor and a reference potential node, and a second capacitor coupled between a second terminal of the first acoustic wave resonator and the first LC tank circuit. In some aspects, the filter circuit includes one or more other filter stages coupled to the first filter stage.

A semiconductor device is provided. The semiconductor device incudes: a first sub-semiconductor structure including a dielectric layer; and a second sub-semiconductor structure, at least including a carrier substrate, and being bonded to the first sub-semiconductor structure. The first sub-semiconductor structure or the second sub-semiconductor structure includes a charge accumulation preventing layer, and the charge accumulation preventing layer is disposed between the carrier substrate and the dielectric layer, and is configured to avoid an undesired conductive channel from being generated due to charge accumulation on a surface of the carrier substrate.

A piezoelectric thin film comprises aluminum nitride containing a monad and at least one type among a tetrad and a pentad. The piezoelectric thin film having a large electromechanical coupling factor and a small stiffness.

A composite device includes a silicon substrate including first and second main surfaces on opposite sides, a semiconductor device adjacent to at least one of the first and second main surfaces, and an acoustic wave device including a silicon oxide film directly or indirectly disposed on the first main surface of the silicon substrate, a piezoelectric layer directly disposed on the silicon oxide film, and an IDT disposed on the piezoelectric layer. The piezoelectric layer has a thickness of not greater than about 2.5 where is a wavelength defined by an electrode finger pitch of the IDT.

An acoustic wave device including a support substrate, a piezoelectric layer provided over the support substrate, at least one pair of comb-shaped electrodes disposed on the piezoelectric layer, each of the at least one pair of comb-shaped electrodes including electrode fingers, a temperature compensation film interposed between the support substrate and the piezoelectric layer, the temperature compensation film having a temperature coefficient of elastic constant opposite in sign to a temperature coefficient of elastic constant of the piezoelectric layer; and an insulating layer interposed between the support substrate and the temperature compensation film, a first surface of the insulating layer having first protruding portions and/or first recessed portions, a second surface of the insulating layer having second protruding portions and/or second recessed portions, the first surface being closer to the support substrate, the second surface being closer to the temperature compensation film.

A compact band pass filter (BPF), including a first transmission line electromagnetically coupled to a second transmission line; and an isolating surface positioned between the first transmission line and the second transmission line, wherein the isolating surface includes at least one aperture designed to produce a desired electromagnetic coupling between the first transmission line and the second transmission line wherein the coupling produces a passband such that certain frequencies within an input transmission signal are filtered out.

A piezoelectric thin film comprises aluminum nitride containing a monad and at least one type among a tetrad and a pentad. The piezoelectric thin film having a large electromechanical coupling factor and a small stiffness.