Taiyo Yuden Co., Ltd.

Fujitsu Corporation

Fujitsu Media Devices Limited

Other

Tsuyoshi Yokoyama

Tokihiro Nishihara

Shinji Taniguchi

Takeshi Sakashita

Masanori Ueda

Masafumi Iwaki

Motoaki Hara

Tsutomu Miyashita

Jun Tsutsumi

Jiansong Liu

Go Endo

Satoshi Ueda

Takeo Takahashi

Xiaoyu Mi

Hiroomi Kaneko

Yasuyuki Saitou

Yoshio Satoh

Hiroshi Kawakami

Yoshiki Iwazaki

Yosuke Onda

Hisanori Ehara

Rei Kimachi

Tsuyoshi Matsumoto

Kazunori Inoue

Kazuhiro Matsumoto

Taisei Irieda

Ryuichi Okamura

Masufumi Iwaki

A piezoelectric thin film resonator includes: a substrate; a piezoelectric film located on the substrate; a lower electrode and an upper electrode facing each other across at least a part of the piezoelectric film; and an insertion film that is inserted between the lower electrode and the upper electrode, is located in an outer peripheral region within a resonance region where the lower electrode and the upper electrode face each other across the piezoelectric film, is located in a region that is located outside the resonance region and surrounds the resonance region, is not located in a center region of the resonance region, and includes a first part, which is located in the resonance region and has a first film thickness, and a second part, which is located outside the resonance region and has a second film thickness, the first film thickness being less than the second film thickness.

Piezoelectric thin film resonator with insertion film, filter, and multiplexer

A piezoelectric thin film resonator includes: a piezoelectric film located on a substrate; lower and upper electrodes facing each other across a part of the piezoelectric film; and an insertion film located between the lower and upper electrodes, located in a part of an outer peripheral region within a resonance region where the lower and upper electrodes face each other across the piezoelectric film, and not located in a center region of the resonance region, a first width in the resonance region of the insertion film in a first region, where the upper electrode is extracted from the resonance region, being greater than a third width in the resonance region in a third region other than a second region, where the lower electrode is extracted from the resonance region, and the first region, a second width in the resonance region in a second region being the third width or greater.

Piezoelectric thin film resonator, filter, and multiplexer

A piezoelectric thin film resonator includes: a substrate; a lower electrode located on the substrate; a piezoelectric film that has a step on an upper surface thereof and is located on the lower electrode, a film thickness of the piezoelectric film inside the step being greater than a film thickness of the piezoelectric film outside the step; an upper electrode located on the piezoelectric film so that a resonance region is formed, the lower electrode and the upper electrode facing each other across the piezoelectric film in the resonance region, the resonance region including the step in plan view; and an insertion film located in the piezoelectric film, between the piezoelectric film and the lower electrode, or between the piezoelectric film and the upper electrode in at least a part of an outer peripheral region within the resonance region, and not located in a central region of the resonance region.

Piezoelectric thin film resonator, filter, and duplexer

An acoustic wave device includes: a piezoelectric film made of an aluminum nitride film containing a divalent element and a tetravalent element, or a divalent element and a pentavalent element; and an electrode that excites an acoustic wave propagating through the piezoelectric film.

Acoustic wave device

A piezoelectric thin film resonator includes: an acoustic reflection layer including an air gap or an acoustic mirror; lower and upper electrodes facing each other in a stacking direction, at least a part of each of the lower and upper electrodes being located on or above the acoustic reflection layer; a piezoelectric film sandwiched between the lower and upper electrodes and including lower and upper piezoelectric films, at least a part of an end face of the piezoelectric film in a film thickness direction being located between outer outlines of the resonance region and the acoustic reflection layer in at least a part of a region surrounding a resonance region; and an insertion film inserted between the lower and upper piezoelectric films, located in at least a part of an outer peripheral region within the resonance region, and not located in a center region of the resonance region.

A piezoelectric thin film resonator includes: lower and upper electrodes located on a substrate and facing each other; a piezoelectric film sandwiched between the lower and upper electrodes and including lower and upper piezoelectric films, an outer outline of the upper piezoelectric film coinciding with or being located further out than an outer outline of a resonance region in a region surrounding the resonance region, the outer outline of the upper piezoelectric film being located further in than an outer outline of the lower piezoelectric film in the region; an insertion film interposed between the lower and upper piezoelectric films, located in an outer peripheral region within the resonance region, not located in a central region of the resonance region, and located on an upper surface of the lower piezoelectric film in the region; and a protective film located on the upper electrode in the resonance region, and located so as to cover an end face of the upper piezoelectric film and an upper surface of the insertion film in the region.

A piezoelectric thin film resonator includes: a substrate; a lower electrode and an upper electrode located on the substrate; a piezoelectric film, at least a part of the piezoelectric film being sandwiched between the upper electrode and the lower electrode, the piezoelectric film including a discontinuous portion in which the piezoelectric film discontinues in at least a part of a region surrounding a center region that includes a center of a resonance region where the upper electrode and the lower electrode face each other across the at least a part of the piezoelectric film.

Piezoelectric thin film resonator and filter

A piezoelectric thin film resonator includes: a piezoelectric film located on a substrate, and formed of stacked lower and upper piezoelectric films; lower and upper electrodes facing each other across at least a part of the piezoelectric film; and an insertion film inserted between the lower and upper piezoelectric films, wherein an air gap including a resonance region where the lower and upper electrodes face each other across the piezoelectric film and being larger than the resonance region is located under the lower electrode, and a multilayered film formed of the lower piezoelectric film, the insertion film, and the upper piezoelectric film is located in at least a part of a region located further out than an outer outline of the resonance region, further in than an outer outline of the air gap, and surrounding the resonance region, and is not located in a center region of the resonance region.

A piezoelectric thin film resonator includes: a substrate; a piezoelectric film located on the substrate, the piezoelectric film including an aluminum nitride film containing a II-group or XII-group element and a IV-group or V-group element, a concentration of the IV-group or V-group element being higher than a concentration of the II-group or XII-group element in a middle region in a thickness direction, the concentration of the II-group or XII-group element being higher than the concentration of the IV-group or V-group element in at least one of end regions in the thickness direction; and a lower electrode and an upper electrode facing each other across the piezoelectric film.

Piezoelectric thin film resonator, filter, duplexer, and method of fabricating piezoelectric thin film resonator

A piezoelectric thin film resonator includes: a substrate; a piezoelectric film located on the substrate and having a Poisson's ratio of 0.33 or less; a lower electrode and an upper electrode facing each other across the piezoelectric film; and an insertion film that is located in the piezoelectric film or on a lower surface or an upper surface of the piezoelectric film in an outer peripheral region within a resonance region, in which the lower electrode and the upper electrode face each other across the piezoelectric film, and is not located in a center region of the resonance region, wherein at least one of the lower electrode, the piezoelectric film, and the upper electrode in the outer peripheral region within the resonance region is thinner than the at least one of the lower electrode, the piezoelectric film, and the upper electrode in the center region of the resonance region.

A piezoelectric thin film resonator includes: a substrate; a piezoelectric film provided on the substrate; a lower electrode and an upper electrode that sandwich at least a part of the piezoelectric film and face with each other; and an inserted film that is inserted in the piezoelectric film, is provided on an outer circumference region in a resonance region in which the lower electrode and the upper electrode sandwich the piezoelectric film and face with each other, is not provided in a center region of the resonance region, and has a cutout in the resonance region.

Piezoelectric thin film resonator, filter and duplexer

A piezoelectric thin film resonator includes: a substrate; a piezoelectric film located on the substrate; a lower electrode and an upper electrode facing each other across at least a part of the piezoelectric film; and an insertion film inserted in the piezoelectric film, located in at least a part of an outer peripheral region within a resonance region where the lower electrode and the upper electrode face each other across the piezoelectric film, and not located in a center region of the resonance region, wherein a difference between a total film thickness of the piezoelectric film and the insertion film in a first region, in which the insertion film is inserted, within the resonance region and a film thickness of the piezoelectric film in a second region, in which the insertion film is not inserted, is less than a film thickness of the insertion film.

Piezoelectric thin film resonator including an insertion film, filter, and duplexer

A piezoelectric thin film resonator includes: a lower electrode and an upper electrode facing each other across a piezoelectric film; an insertion film inserted into the piezoelectric film, located in at least a part of an outer peripheral region in a resonance region and outside the outer peripheral region, and not located in a center region of the resonance region; a protective film on the upper electrode and the piezoelectric film; and a wiring line connecting to the lower electrode and covering an outer periphery of the protective film in an extraction region of the lower electrode, wherein in the extraction region, an outer periphery of the insertion film is further out than an outer periphery of the upper electrode and further in than an outer periphery of the piezoelectric film, and the outer periphery of the protective film is further out than the outer periphery of the insertion film.

Piezoelectric thin film resonator and method of fabricating the same

A filter includes: piezoelectric thin film resonators, each including a substrate, a piezoelectric film located on the substrate, a lower electrode and an upper electrode facing each other across at least a part of the piezoelectric film, and an insertion film inserted in the piezoelectric film, located in at least a part of an outer peripheral region within a resonance region, and not located in a center region of the resonance region, the resonance region being a region where the lower electrode and the upper electrode face each other across the piezoelectric film, wherein at least two piezoelectric thin film resonators out of the piezoelectric thin film resonators have different widths of the insertion films within the resonance regions.

Filter and duplexer with resonators having insertion films of different widths

A piezoelectric thin film resonator includes: a substrate; a piezoelectric film provided on the substrate; a lower electrode and an upper electrode that are opposed to each other to put at least a part of the piezoelectric film therebetween; and an insertion film that is inserted into the piezoelectric film in a resonance region where at least the part of the piezoelectric film is put between the lower electrode and the upper electrode, at least a part of the insertion film corresponding to an outer circumference region in the resonance region being thicker than a part of the insertion film corresponding to a central region in the resonance region.

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Tokyo, Japan

Tsuyoshi Yokoyama