Alps Electric Co., Ltd.

Haruhiko Fujimoto

Satoshi Waga

Kyosuke Ozaki

Takeshi Ikeda

Takashi Sato

Takuo Kudo

Yutaka Matsuo

Kazuaki Kaneko

Toshihiro Meguro

Makoto Sasaki

First base layers made of TiN or TiON(where, 0&#x3c;x&#x3c;0.2, x+y=1) and second base layers made of Cr are provided between interdigital transducer portions and a piezoelectric substrate, and accordingly, it is possible to prevent voids from being generated in the interdigital transducer portions, which improves a power resistance of the surface acoustic wave device. In addition, since it is possible to prevent the voids from being generated in the interdigital transducer portions, it is possible to suppress the resistance of the interdigital transducer portions from increasing, which can reduce the loss of power. In addition, it is also possible to reduce the variations in a serial resonance frequency and a parallel resonance frequency.

Surface acoustic wave device and method of manufacturing the same

A surface acoustic wave element having power resistance is provided. In the surface acoustic wave element, upper dispersion preventing layers and side dispersion preventing layers each made of metal nitride are provided between interdigital transducer electrode portions and an insulating layer. Further, lower dispersion preventing layers made of metal nitride are provided between the interdigital transducer electrode portions and a piezoelectric substrate. If dispersion preventing layers made of 'metal nitride' are provided between the interdigital transducer electrode portions and the insulating layer, even though the insulating layer is formed, it is possible to prevent voids from being generated in the interdigital transducer electrode portions, unlike a related art. Therefore, the power resistance can be improved.

Surface acoustic wave element and method of manufacturing the same

There is provided a surface acoustic wave device which can prevent a breakage of electrodes and electrical breaks, decrease an insertion loss of elements, and enhance a Q-factor of resonators. Interdigital electrode sections and each have a laminated structure of a base layer made of TiN (titanium nitride) or TiONand a main electrode layer deposited to come in contact with an upper surface of the base layer. The main electrode layer is deposited such that a {111} plane as a closest-packed plane of the main electrode layer has a constant gradient with respect to a surface of a substrate, and thus electromigration or stress migration can be suppressed in the interdigital electrode sections.

Surface acoustic wave device

A surface acoustic wave device includes a piezoelectric substrate and an electrode section, disposed on the piezoelectric substrate, having a thin-film structure. The electrode section includes interdigital electrodes and junction electrodes connected to the interdigital electrodes. The interdigital electrodes each include corresponding first base layers containing Ta and Cu layers or Cu&#x2014;M alloy layers each disposed on the corresponding first base layers, wherein M represents one or more elements selected from the group consisting of Ag, Sn, and C.

Surface acoustic wave device having high dielectric strength and process for manufacturing the same

IDT electrodes are formed by a Cu alloy. When the wavelength of a SAW propagating in the direction of the X axis of a piezoelectric substrate is indicated by &#x3bb;, and when the thickness of the IDT electrodes is indicated by H, the standardized thickness H/&#x3bb; of the IDT electrodes ranges from 0.045 to 0.070, and the piezoelectric substrate is a rotated Y-cut LiTaOsubstrate whose rotational cut angle &#x3b8; from the Y axis to the Z axis around the X axis ranges from 52.0&#xb0; to 58.0&#xb0;. With this arrangement, the reflection coefficient S11 becomes 0.88 or higher.

Growing community of inventors

Fukushima-ken, Japan

Haruhiko Fujimoto