Fujitsu Corporation

Taiyo Yuden Co., Ltd.

Fujitsu Media Devices Limited

Hitachi, Ltd.

Other

National Institute of Advanced Industrial Science and Technology

Michio Miura

Takashi Matsuda

Satoru Matsuda

Masanori Ueda

Shogo Inoue

Ippei Sawaki

Seiichi Mitobe

Kazunori Inoue

Masayuki Inoue

Fumitaka Abe

Toshifumi Takeuchi

Yoshio Suzuki

Mikio Shiraishi

Osamu Ikata

Masafumi Nakamura

Kiyoshi Kano

Yasuo Ohtsuka

Suguru Warashina

Yoshio Satoh

Shinro Inui

Katsuhiko Izumi

Yoshiro Ishikawa

Naomitsu Kuroda

Ryuichiro Mizuno

Naohiko Otoshi

Shinji Yamamoto

Satoshi Ueda

Takashi Katsuki

Naoyuki Mishima

Masahiko Imai

Hitoshi Tsukidate

Sunao Kurimura

Tohru Sasaki

Kazuo Shigematsu

Takashi Yamashita

Osamu Kawachi

Yasuo Otsuka

Kunikazu Ohnishi

Takuma Kuroyanagi

Yasufumi Kaneda

Hideki Takagi

Akira Saito

Shinya Fujimori

Seiichi Kato

Shunichi Aikawa

Akio Yabe

Kaoru Sakinada

Kichizaemon Okazaki

Nobuyuki Maeda

Ryohei Komiyama

Tooru Takezaki

Koichi Satoh

Hiraki Domon

Hiroyoshi Yasuda

Toru Uemura

Kunihisa Wada

An acoustic wave device includes a support substrate having an uneven surface, a piezoelectric layer provided on the uneven surface of the support substrate, an electrode that excites an acoustic wave in the piezoelectric layer, and an insulating layer that is provided between the uneven surface of the support substrate and the piezoelectric layer, and has an air gap located in a recess part of the uneven surface.

Acoustic wave device and wafer with support substrate having an uneven surface, and manufacturing method of wafer

An acoustic wave device includes: a piezoelectric substrate: a pair of comb-shaped electrodes located on the piezoelectric substrate, each of the comb-shaped electrodes including a plurality of electrode fingers; a support substrate having protruding portions and/or recessed portions in a region overlapping with the pair of comb-shaped electrodes in plan view, the protruding portions and/or recessed portions being regularly arranged; and an insulating layer directly or indirectly bonded between the piezoelectric substrate and the support substrate, a boundary face between the insulating layer and the support substrate being provided along the protruding portions and/or the recessed portions.

Acoustic wave device, filter, and multiplexer

An elastic wave device includes resonators having a piezoelectric substrate, a resonation unit formed on the piezoelectric substrate, and reflectors formed on respective sides of the resonation unit on the piezoelectric substrate, and bumps formed on the piezoelectric substrate. The resonators are configured such that two or more split resonators are connected in parallel, and a bump is formed in a region sandwiched between reflectors of the split resonators.

Elastic wave device, duplexer using the same, and communication apparatus using the duplexer

Acoustic wave device includes: a piezoelectric substrate; a first IDT located on the piezoelectric substrate; and a second IDT located on the piezoelectric substrate and connected in series to the first IDT, wherein the first IDT and the second IDT share a single common bus bar as a first bus bar of two bus bars of the first IDT and a first bus bar of two bus bars of the second IDT, and the common bus bar has a width not more than two times a wavelength of an acoustic wave propagating through the first and second IDTs, the common bus bar connects to no dummy electrode finger facing a tip of an electrode finger connected to a second bus bar of the two bus bars of the first IDT and the second IDT across a gap.

Acoustic wave device, filter, and duplexer

A configuration that reduces a parasitic capacitance between wires is achieved at a low cost. Disclosed is an acoustic wave filter provided with a piezoelectric substrate, resonators that include a comb-shaped electrode formed on the piezoelectric substrate, a wiring portion that is connected to the comb-shaped electrode, and a dielectric layer formed to cover the comb-shaped electrode. The wiring portion is provided with a lower layer wiring portion that is disposed in the same layer as the comb-shaped electrode and an upper layer wiring portion that is disposed on the lower layer wiring portion. The upper layer wiring portion includes a region that has a wider electrode width than the electrode width of the lower layer wiring portion.

Acoustic wave filter

An acoustic wave device includes: an electrode that is located on a substrate and excites an acoustic wave; and an oxide silicon film that is doped with an element and provided so as to cover the electrode, wherein a normalized reflectance obtained by normalizing a local maximum value of a reflectance when a light is caused to enter an upper surface of the oxide silicon film doped with the element by a reflectance when a light having a wavelength at the local maximum value is caused to enter an upper surface of the substrate directly is equal to or larger than 0.96.

Acoustic wave device

An acoustic wave device includes a substrate, a dielectric film formed on the substrate and a pair of IDT electrodes opposing each other provided between the substrate and the dielectric film. At least one of the substrate and the dielectric film is piezoelectric. The IDT electrodes each include an electrode finger that extends in at least one direction. A film thickness of the dielectric film changes in a gap portion between a tip of the electrode finger of one of the IDT electrodes and the other opposing IDT electrode in the direction of extension of the electrode finger.

An acoustic wave device includes: a comb-like electrode provided on a piezoelectric substrate; and a first medium that covers the comb-like electrode and has at least a silicon oxide film in which an element is doped, wherein sonic speed in the silicon oxide film in which the element is doped is lower than sonic speed in an undoped silicon oxide film.

An acoustic wave device includes: a substrate; a dielectric film formed on the substrate; opposing comb-shaped electrodes located between the substrate and the dielectric film, each of the opposing comb-shaped electrodes including an electrode finger, wherein at least one of the substrate and the dielectric film is a piezoelectric substance, an upper surface of the dielectric film, which is located above a gap between a tip of an electrode finger of one of the opposing comb-shaped electrodes and the other of the opposing comb-shaped electrodes, is inclined against an upper surface of the substrate in an extension direction of the electrode finger, and an inclination angle of the upper surface of the dielectric film against the upper surface of the substrate is equal to or larger than 30&#xb0; and equal to or smaller than 50&#xb0;.

Acoustic wave device and module including a dielectric film with an inclined upper surface

A method of producing an acoustic wave device includes: forming an interdigital electrode on a piezoelectric substrate; forming a barrier film so as to cover the interdigital electrode; forming a medium on the barrier film; measuring a frequency characteristic of an acoustic wave excited by the interdigital electrode; and forming, in an excitation region, an adjustment region having a thickness different from other portions by patterning the barrier film or further providing an adjustment film. When forming the adjustment region, an area T of the adjusting area is adjusted in accordance with the measured frequency characteristic.

Method of producing an acoustic wave device

An acoustic wave device includes: an electrode that excites an acoustic wave and is located on a substrate; and a silicon oxide film that is located so as to cover the electrode and is doped with an element or molecule displacing O in a Si&#x2014;O bond, wherein the element or molecule is F, H, CH, CH, Cl, C, N, P, or S.

An acoustic wave device includes a plurality of acoustic wave devices each including a substrate made of a piezoelectric material, a pair of interdigital electrodes formed on the substrate, each of the interdigital electrodes including a plurality of electrode fingers, and an adjustment medium. The adjustment medium includes at least a single layer and is formed on at least a part of the pair of the interdigital electrodes. The adjustment medium further includes at least one thick portion and a thin portion, the thin portion being null or thinner than the thick portion, a total area of the at least one thick portion in a region covering the pair of interdigital electrodes being determined according to a predetermined characteristic value, wherein the plurality of acoustic wave devices include at least two acoustic wave devices that differ from each other with respect to the size of the total area of the at least one thick portion of the adjustment medium.

Acoustic wave device, transmission apparatus, and acoustic wave device manufacturing method

In an acoustic wave filter, a notch resonator is connected in series or parallel with a plurality of acoustic wave resonators connected in a ladder shape. The notch resonator has a main resonant frequency that is substantially equal to a sub-resonant frequency of the acoustic wave resonators. With this configuration, the occurrence of sub-resonant responses in filter characteristics can be suppressed, resulting in an improvement in communication characteristics.

Acoustic wave filter, duplexer, communication module, and communication apparatus

A boundary acoustic waves device includes a piezoelectric substrate having piezoelectricity, interdigitated electrodes formed on the piezoelectric substrate, a first medium formed on the piezoelectric substrate so as to cover the interdigitated electrode, and a second medium formed on the first medium. The interdigitated electrodes include a plurality of electrode fingers and bus bars that connect ends of the plurality of electrode fingers. A third medium is formed on the first medium. The second medium and the third medium are in contact with the first medium. The first medium, the second medium, and the third medium are formed of different materials. The first medium, the second medium, and the third medium are different in a ratio in length of a part with the third medium formed with respect to a length of a propagation path of boundary acoustic waves in a cross-section perpendicular to a longitudinal direction of the electrode fingers, in the longitudinal direction of the electrode fingers.

Boundary acoustic wave device and communication equipment

An acoustic wave device includes a piezoelectric substrate, interdigital electrodes arranged on the piezoelectric substrate, a first dielectric element arranged between the interdigital electrodes, a second dielectric element that covers the interdigital electrodes and the first dielectric element, and an adjustment element that has been formed on the first dielectric element. The adjustment element has been formed from a material whose specific gravity is greater than that of the first dielectric element and that of the second dielectric element.

Acoustic wave device, duplexer, communication module, communication apparatus, and manufacturing method for acoustic wave device

Growing community of inventors

Kawasaki, Japan

Michio Miura