Acoustic resonators, filters, and methods. An acoustic resonator includes a substrate, a piezoelectric plate, and a diaphragm including a portion of the piezoelectric plate spanning a cavity in a substrate. An interdigital transducer (IDT) on a front surface of the piezoelectric plate includes first and second sets of interleaved interdigital transducer (IDT) fingers extending from first and second busbars respectively. The interleaved IDT fingers extend onto the diaphragm. Overlapping portions of the interleaved IDT fingers define an aperture of the acoustic resonator. First and second dielectric strips are on the front surface of the piezoelectric plate. Each dielectric strip has a first portion under the IDT fingers in a respective margin of the aperture and a second portion extending into a gap between the respective margin and the respective busbar.

Acoustic resonators, filters, and methods. An acoustic resonator includes a substrate, piezoelectric plate, and a diaphragm comprising a portion of the piezoelectric plate spanning a cavity in a substrate. An interdigital transducer (IDT) on a front surface of the piezoelectric plate includes first and second sets of interleaved interdigital transducer (IDT) fingers extending from first and second busbars respectively. The interleaved IDT fingers are on the diaphragm. Overlapping portions of the interleaved IDT fingers define an aperture of the acoustic resonator. A first dielectric strip overlaps the IDT fingers in a first margin of the aperture and extends into a first gap between the first margin and the first busbar. A second dielectric strip overlaps the IDT fingers in a second margin of the aperture and extends into a second gap between the second margin and the second busbar.

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.

An elastic wave device includes a supporting substrate, an acoustic reflection layer on the supporting substrate, a piezoelectric layer on the acoustic reflection layer, and an IDT electrode on the piezoelectric layer. The acoustic reflection layer includes three or more low-acoustic impedance layers and two or more high-acoustic impedance layers. At least one of a first relationship in which in which, a film thickness of a first low-acoustic impedance layer closest to the piezoelectric layer is thinner than a film thickness of a low-acoustic impedance layer closest to the first low-acoustic impedance layer, and a second relationship in which a film thickness of a first high-acoustic impedance layer closest to the piezoelectric layer is thinner than a film thickness of a high-acoustic impedance layer closest to the first high-acoustic impedance layer, is satisfied.

Disclosed is a Bulk Acoustic Wave (BAW) filter structure with a conductive bridge forming an electrical loop with an electrode for reduced electrical losses. In exemplary aspects disclosed herein, the BAW filter structure includes a transducer with electrodes, a piezoelectric layer between the electrodes, and at least one conductive bridge offset from at least a portion of one of the electrodes by an insulating volume. The conductive bridge forms a first electrical loop between a medial end and a distal end of the electrode. Such a configuration reduces electrical resistance, heat resistance, and/or ohmic losses for improved electrical loss of the BAW filter structure.

An acoustic resonator includes a substrate, an insulation layer disposed on the substrate, a resonating portion disposed on the insulation layer and having a first electrode, a piezoelectric layer, and a second electrode, stacked thereon, a cavity disposed between the insulation layer and the resonating portion, a protruded portion having a plurality of protrusions disposed on a lower surface of the cavity, and a hydrophobic layer disposed on an upper surface of the cavity and a surface of the protruded portion.

A bulk-acoustic resonator module includes: a module substrate; a bulk-acoustic resonator connected to the module substrate by a connection terminal and disposed spaced apart from the module substrate; and a sealing portion sealing the bulk-acoustic resonator. The bulk-acoustic resonator includes a resonating portion disposed opposite to an upper surface of the module substrate. A space is disposed between the resonating portion and the upper surface of the module substrate.

A solidly mounted resonator having an electromagnetic shielding structure and a method for manufacturing the same. The solidly mounted resonator includes: a substrate; an acoustic-wave reflecting layer formed on the substrate; a resonance function layer formed on the acoustic-wave reflecting layer; and a metal shielding wall formed on the substrate, wherein the metal shielding wall surrounds an effective region in the acoustic-wave reflecting layer and the resonance function layer. The electromagnetic shielding structure is formed simultaneously with the resonator, and it is not necessary to provide an additional electromagnetic shielding device. An influence of an external or internal electromagnetic interference source on the resonator is avoided while ensuring a small dimension and a high performance of the resonator.

A high frequency module includes a mounting substrate, an acoustic wave filter, a protection member, a resin layer, and a shield layer. The acoustic wave filter is mounted on a first main surface of the mounting substrate. The protection member is disposed on a main surface of the acoustic wave filter that is far from the mounting substrate. The resin layer is disposed on the first main surface of the mounting substrate and covers an outer peripheral surface of the acoustic wave filter and an outer peripheral surface of the protection member. The shield layer covers the resin layer and the protection member. The protection member is in contact with both the acoustic wave filter and the shield layer. The acoustic wave filter includes a piezoelectric substrate. A main surface of the piezoelectric substrate that is far from the mounting substrate is in contact with the protection member.

Embodiments of this disclosure relate to bulk acoustic wave resonators on a substrate. The bulk acoustic wave resonators include a first bulk acoustic wave resonator, a second bulk acoustic wave resonator, a conductor electrically connecting the first bulk acoustic wave resonator to the second bulk acoustic wave resonator, and an air gap positioned between the conductor and a surface of the substrate.