Murata Manufacturing Co., Ltd.

Murata Mfg. Co., Ltd.

Hideharu Ieki

Jun Koike

Atushi Inoue

Atsushi Sakurai

Koji Kimura

Hideki Ishiyama

Tadamasa Ushiroku

Satoru Fujishima

Hiroki Watanabe

Seiichi Arai

Yutaka Tada

Akira Kawabata

Takaharu Kawakatsu

Fumio Takeda

Tadashi Shiosaki

A ZnO/sapphire substrate includes an R-plane sapphire substrate whose (0 1-1 2) planes are parallel to the surface thereof and a ZnO epitaxial film formed on the R-plane sapphire substrate. The (1 1-2 0) planes of the ZnO epitaxial film are disposed with an interplanar spacing in the range of about 1.623 to 1.627 &angst; parallel to the (0 1-1 2) planes of the R-plane sapphire substrate.

ZnO/sapphire substrate and method for manufacturing the same

An inexpensive surface acoustic wave apparatus uses a flip chip bonding technique and is capable of reducing an ohmic loss by reducing an electrode electrical resistance and also operates at a high-frequency range. A surface acoustic wave apparatus has a surface acoustic wave element bonded to a package by using a bonding flip chip technique. In the surface acoustic wave element, on a piezoelectric substrate, an IDT electrode, bus bar electrodes, reflector electrodes, relay electrodes, and electrode pads are disposed. Conductive films are disposed on the electrode pads and define a first metallic film, and the conductive films are also disposed on at least any of the bus bar electrodes and the relay electrodes to define a second metallic film.

Surface acoustic wave element and manufacturing method of the same

A surface acoustic wave (SAW) filter includes a plurality of interdigital transducers located on a piezoelectric substrate along a surface wave propagation direction, at least a single one-port SAW resonator being connected in parallel with an output side of the SAW filter, while the resonance frequency (f.sub.0) of the SAW resonator is set in frequency region level which is lower than the pass band of the SAW filter.

Surface acoustic wave filter

A surface acoustic wave (SAW) filter includes a plurality of interdigital transducers located on a piezoelectric substrate along a surface wave propagation direction, at least a single one-port SAW resonator connected in series with an output side of the SAW filter, while the resonance frequency of the SAW resonator is set at a level which is higher than the passband of the SAW filter.

When a zinc oxide piezoelectric crystal film is epitaxially grown on an R-plane sapphire substrate by sputtering, a target containing not more than 4.5 percent by weight of Cu with respect to the total content of Zn and Cu is employed so that the zinc oxide piezoelectric film contains Cu. Thus, it is possible to obtain a zinc oxide piezoelectric crystal film having excellent orientation.

Zinc oxide piezoelectric crystal film on sapphire plane

An IIDT type surface acoustic wave filter (41) comprising a piezoelectric substrate and at least three IDTs (44 to 46) which are arranged on a surface of the piezoelectric substrate along the direction of surface wave propagation, the IDT (44) being inverted in phase with respect to the other IDT (46) while these IDTs (44) and (46) are connected in series to each other through the ground potential, thereby balancing inputs or outputs.

IIDT type surface acoustic wave device

Disclosed herein is a zinc oxide piezoelectric crystal film which is grown on an R-plane sapphire substrate to orient its c-axis in parallel with the substrate surface. In order to improve orientation of the zinc oxide piezoelectric crystal film used is a Zn target for forming the zinc oxide piezoelectric crystal film by sputtering contains not more than 5 percent by weight of nickel or not more than 4.5 percent by weight of iron with respect to Zn.

Zinc oxide piezoelectric crystal film

Interdigital transducers (3, 4) and reflectors (5, 6) are formed on a piezoelectric substrate (2) by an aluminum film. The aluminum film is crystallographically oriented in a constant direction, whereby stressmigration of the aluminum film is suppressed.

Surface acoustic wave device

Interdigital transducers and reflectors are formed on a piezoelectric substrate from an aluminum film. The aluminum film is formed by electron beam deposition at a film forming rate which is controlled to be at least 20 .ANG. per second. The aluminum film formed in this way is crystallographically oriented in a constant direction, whereby stressmigration of the aluminum film is suppressed.

Method of manufacturing surface acoustic wave device

A surface accoustic wave device includes a substrate which is made up of single-crystalline dielectric member and a piezoelectric thin film epitaxially grown thereon. An aluminum electrode defining an interdigital electrode is formed along the interface between the dielectric member and the piezoelectric thin film. This aluminum electrode is formed of an aluminum film which is crystallographically oriented in a constant direction, whereby stressmigration of the aluminum electrode is suppressed, while enabling epitaxial growth of the piezoelectric thin film over the entire surface insert.

A surface acoustic wave device comprising a surface acoustic wave substrate member composed by forming an aluminum oxide film and a thin zinc oxide film successively on a glass substrate. The thickness h.sub.1 of the aluminum oxide film and the thickness h.sub.2 of the zinc oxide film are set within ranges of 0.1.ltoreq.h.sub.1 /.lambda..ltoreq.10 and 0.05.ltoreq.h.sub.2 /.lambda..ltoreq.0.35 (where .lambda. is representative of wavelength of Sezawa wave) respectively, thereby to utilize Sezawa wave or a similar mode wave transmitted on the surface acoustic wave substrate member in multi-layer structure.

A surface acoustic wave device comprising a surface acoustic wave substrate member composed by forming an aluminum nitride film and a thin zinc oxide film successively on a glass substrate. The thickness h.sub.1 of the aluminum nitride film and the thickness h.sub.2 of the zinc oxide film are set within ranges of 0.1.ltoreq.h.sub.1 /.lambda..ltoreq.10 and 0.05.ltoreq.h.sub.2 /.lambda..ltoreq.0.3 (where .lambda. is representative of wavelength of Sezawa wave) respectively, thereby to utilize Sezawa wave or a similar mode wave transmitted on the surface acoustic wave substrate member in multi-layer structure.

Sezawa surface acoustic wave device using a piezoelectric layer over a

A surface acoustic wave device includes a piezoelectric substrate, transmitting and receiving transducers provided on the surface of the substrate for propagating acoustic waves between the transducers, and absorbers provided between an end of the substrate and respective transducers for absorbing unwanted acoustic waves. The shape of the absorber is in relation to the energy distribution of the acoustic waves.

Absorber for piezoelectric surface acoustic wave device

A surface acoustic wave device comprises an input and output transducers. A signal is supplied from a signal input circuit to the input transducer and a surface wave corresponding to the input signal is propagated from the input transducer to the output transducer, from which an electrical signal corresponding to the surface wave is withdrawn and is applied to a signal output circuit. An impedance converting circuit is inserted in series between the signal input circuit and the input transducer and/or between the output transducer and the signal output circuit. It has been discovered that this arrangement reduces the electrical triple transit echo.

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Kyoto, Japan

Hideharu Ieki