Murata Manufacturing Co., Ltd.

National Institute of Advanced Industrial Science

Masashi Omura

Yutaka Kishimoto

Tetsuya Kimura

Daisuke Miyazaki

Ryoichi Omote

Nobuhira Tanaka

Keiichi Umeda

Morito Akiyama

Norio Taniguchi

Takashi Yamane

Yasumasa Taniguchi

Katsuhiro Ikada

Toshiyuki Baba

Koji Yamamoto

Makoto Kumatoriya

Hiromu Okunaga

Atsushi Tanaka

Atsushi Honda

Jun Nakanishi

Yoshiki Ryu

An acoustic wave device includes a piezoelectric member, a first and second electrodes on first and second main surfaces of the piezoelectric member, an acoustic reflection section including an air gap, and an additional mass film in at least one of areas on the first and second electrodes and an area outward of the first or second electrodes. A region where at least one of the first electrode and the additional mass film overlaps the second electrode includes a first region and a second region surrounding the first region. In the second region, a configuration of additional mass film portions on corresponding sides of a first direction in a plane of the piezoelectric member and a configuration of additional mass film portions on corresponding sides of a second direction in the plane of the piezoelectric member are different from each other.

Acoustic wave device

An acoustic wave device includes a support substrate, and a piezoelectric layer provided on the support substrate. The piezoelectric layer has a first main surface opposite to a second main surface. The piezoelectric layer also includes a first direction orthogonal to a second direction. A first electrode is provided on the piezoelectric layer's first main surface, and a second electrode is provided on the piezoelectric layer's second main surface to face the first electrode. An energy confining portion is provided between the support substrate and the piezoelectric layer. The piezoelectric layer is anisotropic with respect to a coefficient of linear expansion, and in the piezoelectric layer, a coefficient of linear expansion in the first direction is different from a coefficient of linear expansion in the second direction. At least one of the piezoelectric layer, the first electrode, and the second electrode is parallel to the first direction.

An acoustic wave filter device includes a substrate, first and second acoustic impedance layers, a piezoelectric layer, first and second interdigital transducer electrodes, an input terminal, an output terminal, ground terminals, a series arm circuit, and a parallel arm circuits. The first interdigital transducer electrode at least partially overlaps the first acoustic impedance layer in the plan view. The second interdigital transducer electrode at least partially overlaps the second acoustic impedance layer in the plan view. The series arm circuit is provided on a first path connecting the input terminal and the output terminal and includes the first and second interdigital transducer electrodes. A conductive layer in the first acoustic impedance layer and a conductive layer in the second acoustic impedance layer are electrically insulated from each other.

Acoustic wave filter device

An acoustic wave device includes a supporting substrate, an acoustic reflection layer, a piezoelectric layer, and an IDT electrode. At least one of a high acoustic impedance layer and a low acoustic impedance layer is a conductive layer in the acoustic reflection layer. When a wavelength of an acoustic wave determined by an electrode finger pitch of the IDT electrode is &#x3bb; and a region between an envelope of tips of first electrode fingers and an envelope of tips of second electrode fingers is an intersecting region, the conductive layer overlaps at least the intersecting region in plan view in a thickness direction of the supporting substrate, and a distance from the tips of the first electrode fingers to an end of the conductive layer in a direction in which the first electrode fingers extend is more than 0 and not more than about 12&#x3bb;.

An elastic wave device includes a supporting substrate, an acoustic multilayer film on the supporting substrate, a piezoelectric substrate on the acoustic multilayer film, and an IDT electrode on the piezoelectric substrate. An absolute value of a thermal expansion coefficient of the piezoelectric substrate is larger than an absolute value of a thermal expansion coefficient of the supporting substrate. The acoustic multilayer film includes at least four acoustic impedance layers. The elastic wave device further includes a bonding layer provided at any position in a range of from inside the first acoustic impedance layer from the piezoelectric substrate side towards the supporting substrate side, to an interface between the third acoustic impedance layer and the fourth acoustic impedance layer.

Elastic wave device

An elastic wave device includes a supporting substrate including an upper surface including a recessed portion, a piezoelectric thin film on the supporting substrate to cover the recessed portion of the supporting substrate, an IDT electrode on a main surface of the piezoelectric thin film, the main surface being adjacent to the supporting substrate, and an intermediate layer on a main surface of the piezoelectric thin film, the main surface being remote from the supporting substrate. A space is defined by the supporting substrate and the piezoelectric thin film. The IDT electrode faces the space. Through holes are provided in the piezoelectric thin film and the intermediate layer to extend from a main surface of the intermediate layer to the space, the main surface being remote from the piezoelectric thin film. The elastic wave device further includes a cover member on the intermediate layer and covering opening ends of the through holes.

Elastic wave device and method for producing the same

An acoustic wave device includes first and second IDT electrodes electrically connected in series with each other by a common busbar common to the first and second IDT electrodes. In each of a first acoustic impedance layer and a second acoustic impedance layer, at least one of at least one high acoustic impedance layer and at least one low acoustic impedance layer is a conductive layer. At least a portion of the conductive layer in the first acoustic impedance layer and at least a portion of the conductive layer in the second acoustic impedance layer do not overlap with the common busbar when viewed in plan from a thickness direction of a piezoelectric layer. The conductive layer in the first acoustic impedance layer and the conductive layer in the second acoustic impedance layer are electrically insulated from each other.

An acoustic wave device includes a first acoustic impedance layer and a second acoustic impedance layer, an IDT electrode, and an electrode. At least a portion of the IDT electrode overlaps the first acoustic impedance layer. At least a portion of the electrode overlaps the second acoustic impedance layer. In each of the first acoustic impedance layer and the second acoustic impedance layer, at least one of a high acoustic impedance layer and a low acoustic impedance layer is a conductive layer. A capacitor is formed by using the conductive layer of the second acoustic impedance layer and the electrode. The conductive layer in the first acoustic impedance layer is electrically insulated from the conductive layer in the second acoustic impedance layer.

Acoustic wave device and method for manufacturing acoustic wave device

An elastic wave device includes a supporting substrate, an acoustic multilayer film on the supporting substrate, a piezoelectric substrate on the acoustic multilayer film, and an IDT electrode on the piezoelectric substrate. The acoustic multilayer film includes at least four acoustic impedance layers. The at least four acoustic impedance layers include at least one low acoustic impedance layer and at least one high acoustic impedance layer having an acoustic impedance higher than the low acoustic impedance layer. The elastic wave device further includes a bonding layer provided at any position in a range of from inside the acoustic impedance layer, which is the fourth acoustic impedance layer from the piezoelectric substrate side towards the supporting substrate side, to an interface between the acoustic multilayer film and the supporting substrate.

An elastic wave device in which an IDT electrode defines an excitation electrode on a piezoelectric layer, an acoustic reflection layer is laminated on a first main surface of the piezoelectric layer, the acoustic reflection layer includes high acoustic impedance layers with a relatively high acoustic impedance and low acoustic impedance layers with a relatively low acoustic impedance, and the acoustic reflection layer has an unwanted wave reflection suppression structure in which reflection of unwanted waves toward the piezoelectric layer side is significantly reduced or prevented.

Elastic wave device and manufacturing method therefor

An elastic wave device includes an interdigital transducer electrode including electrode fingers provided on a first principal surface of a piezoelectric thin film. A conductive layer is provided on a second principal surface of the piezoelectric thin film. An elastic wave propagates in the piezoelectric thin film in an S0 mode of a plate wave, and a piezoelectric thin film portion in a region below spaces between the electrode fingers of the interdigital transducer electrode is displaced by a greater amount than each electrode finger and a piezoelectric thin film portion in a region below each electrode finger.

An acoustic wave device includes a supporting substrate, an acoustic reflection film the supporting substrate, a piezoelectric thin film on the acoustic reflection film, and an interdigital transducer electrode the piezoelectric thin film. The acoustic reflection film includes acoustic impedance layers including therein first, second, third, and fourth low acoustic impedance layers and first, second, and third high acoustic impedance layers. The acoustic reflection film includes a first acoustic impedance layer and a second acoustic impedance layer, the first and second acoustic impedance layers each being one of the acoustic impedance layers, and the second acoustic impedance layer has an arithmetic average roughness different from that of the first acoustic impedance layer.

Acoustic wave device, high frequency front-end circuit, and communication device

An acoustic wave device includes a support substrate, a piezoelectric laminate, and first and second interdigital transducer electrodes. The piezoelectric laminate includes an intermediate layer provided directly or indirectly on the support substrate and a piezoelectric thin film provided on the intermediate layer. The first and second interdigital transducer electrodes are provided on the piezoelectric thin film of the piezoelectric laminate so as to be disposed in an identical or substantially identical plane. In the piezoelectric laminate, a thickness of a portion where the first interdigital transducer electrode is provided is different from a thickness of a portion where the second interdigital transducer electrode is provided.

In an elastic wave device, a piezoelectric substrate is stacked on a support substrate and an IDT electrode is provided on the piezoelectric substrate. Wiring line portions are provided on the piezoelectric substrate. A first hollow portion is provided in the support substrate at least below at least one of the wiring line portions and or below a region between the wiring line portions.

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&#x3bb; where &#x3bb; is a wavelength defined by an electrode finger pitch of the IDT.

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Nagaokakyo, Japan

Masashi Omura