Elastic wave device, radio-frequency front-end circuit, and communication device
AssigneeMurata Manufacturing Co., Ltd.
InventorYasumasa TANIGUCHI
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Abstract
An elastic wave device includes a piezoelectric material layer, an IDT electrode on the piezoelectric material layer, and a dielectric film covering the IDT electrode. The IDT electrode includes a first electrode layer and a second electrode layer laminated on the first electrode layer. Each of wavelength normalized film thicknesses of the first and second electrode layers is equal to or greater than about 1.25%, and is normalized using a wave length defined by the electrode finger pitch of the IDT electrode. The second electrode layer has a density lower than that of the first electrode layer. The side of the second electrode layer is inclined with respect to the thickness direction of the IDT electrode.
Claims19
An elastic wave device comprising:
- a piezoelectric material layer;
- an IDT electrode disposed on the piezoelectric material layer;
- and
- a dielectric film that covers at least a portion of the IDT electrode;
- wherein
- the IDT electrode includes a first electrode layer and a second electrode layer laminated on the first electrode layer;
- each of wavelength normalized film thicknesses of the first and second electrode layers is equal to or greater than about 1.25%, the wavelength normalized film thicknesses of the first and second electrode layers being normalized using a wavelength defined by electrode finger pitch of the IDT electrode;
- the second electrode layer has a density lower than a density of the first electrode layer;
- and
- a side of the second electrode layer is inclined with respect to a thickness direction of the IDT electrode.
Dependencies are inferred from the claim text.