An acoustic wave device includes a support substrate, a piezoelectric layer, and an IDT electrode. The piezoelectric layer is over the support substrate. The IDT electrode is on the piezoelectric layer, and includes a plurality of electrode fingers. An intersecting width of the plurality of electrode fingers is equal to or smaller than about 5λ.

An acoustic wave device includes a piezoelectric layer and an interdigital transducer disposed on the piezoelectric layer. The interdigital transducer primarily includes Al and includes an additive selected from a group consisting of Nd, Sc, and Ta, and a concentration of the additive in a region opposite to a piezoelectric-layer-side region of the interdigital transducer is higher than a concentration of the additive in the piezoelectric-layer-side region of the interdigital transducer.

An electronic component includes a support member, a piezoelectric film, and an interdigital transducer. The support member includes silicon as a primary component. The piezoelectric film is provided directly or indirectly on the support member. The interdigital transducer includes a plurality of electrode fingers. The plurality of electrode fingers are provided side by side separately from each other. The interdigital transducer is provided on the principal surface of the piezoelectric film. The film thickness of the piezoelectric film is about 3.5 λ or less, where λ denotes the wavelength of an acoustic wave determined by the electrode finger pitch of the interdigital transducer. In the support member, the high-impurity-concentration region is further from the piezoelectric film than the low-impurity-concentration region.

The present invention relates to a transducer structure with transverse mode suppression means, in particular for a single-port resonator, comprising a piezoelectric substrate (120, 170), at least a pair of inter-digitated comb electrodes (102, 112) formed on the piezoelectric substrate (120, 170), wherein the first comb electrode (102) comprises a first bus bar (108) and a plurality of electrode fingers (104) alternating with shorter dummy electrode fingers (106), both extending from the first bus bar (108), wherein the second comb electrode (112) comprises a second bus bar (118) and a plurality of electrode fingers (114) extending from the second bus bar (118), wherein the dummy electrode fingers (106) of the first bus bar (108) face the electrode fingers (114) of the second bus bar (118) and are separated from the electrode fingers (114) by first gaps (110a), characterized in further comprising a transverse mode suppression layer (122, 132, 222, 232, 422, 432) provided partially underneath the first gap (110a) and chosen such that the phase velocity of a guided wave is smaller in the region of the transverse mode suppression layer (122, 132, 222, 232, 422, 432) compared to the phase velocity of the guided wave in the central region (136) underneath the alternating electrodes fingers (104, 114) of the first and second electrodes (102, 112). The present invention also relates to a method for fabricating the transducer structure as previously described and to a single-port resonator comprising at least one structure as previously described.

An acoustic wave device includes a substrate including a piezoelectric layer, first and second resonators on the substrate, and a shared reflector. The second resonator is located on the substrate adjacent to the first resonator and has different frequency characteristics than the first resonator. The shared reflector is located on the substrate between the first resonator and the second resonator and is a reflector for both the first resonator and the second resonator. The first resonator includes a first interdigital transducer electrode with electrode fingers positioned with a first pitch. The second resonator includes a second interdigital transducer electrode with electrode fingers positioned with a second pitch. A lower limit frequency of a stop band of the shared reflector is between a lower limit frequency of a stop band of the first resonator and a lower limit frequency of a stop band of the second resonator. An upper limit frequency of the stop band of the shared reflector is between an upper limit frequency of the stop band of the first resonator and an upper limit frequency of the stop band of the second resonator.

An acoustic wave device is disclosed. The acoustic waved device can be a shear horizontal mode surface acoustic wave device. The acoustic wave device can include a piezoelectric layer, an interdigital transducer electrode over the piezoelectric layer, and a temperature compensation layer over the interdigital transducer electrode. The piezoelectric layer can be a lithium niobate layer with a cut angle in a range of −20° YX to 25° YX. The interdigital transducer electrode includes a first layer having a first thickness and a second layer having a second thickness. The first layer affects acoustic properties of the acoustic wave device and the second layer affects electrical properties of the acoustic wave device. The first layer is positioned between the piezoelectric layer and the second layer. The first thickness is configured such that a frequency response of the acoustic wave device includes a Rayleigh mode response at a frequency higher than a shear horizontal mode response resonance. The first thickness can be greater than the second thickness.

An elastic wave device includes a piezoelectric film laminated on a first main surface of a support substrate including a recessed portion open to a first main surface. A cavity portion including the recessed portion is defined by the support substrate and the piezoelectric film. An electrode is on the piezoelectric film. The electrode includes first and second bus bars, a first electrode finger connected to the first bus bar, and a second electrode finger connected to the second bus bar. The first and second bus bars include corner portions inside the cavity portion when viewed in plan view. A curved portion as a pressure relaxation portion to relax pressure on the piezoelectric film at at least one of the corner portions of the first and second bus bars is provided between the corner portion and an outer edge of the cavity portion.

An acoustic wave device is disclosed. The acoustic wave device can include a piezoelectric layer, an interdigital transducer electrode over the piezoelectric layer, a temperature compensation layer over the interdigital transducer electrode, and a dielectric layer that is positioned partially between the piezoelectric layer and the interdigital transducer electrode. The dielectric layer that is positioned so as to partially electro-mechanically de-couple the piezoelectric layer from the interdigital transducer electrode.

Multi-mode surface acoustic wave filters are disclosed. A multi-mode surface acoustic wave filter can include a plurality of interdigital transducer electrodes that are longitudinally coupled to each other and acoustic reflectors on opposing sides of the plurality of interdigital transducer electrodes. The acoustic reflectors include acoustic reflector fingers arranged to suppress a spurious response due to shear horizontal mode of the multi-mode surface acoustic wave filter. For example, the acoustic reflector fingers can include stepped lengths and/or slanted pitches to suppress the spurious response due to shear horizontal mode.

An acoustic wave device includes a piezoelectric substrate and an IDT electrode. In the IDT electrode, at least one electrode finger includes a first portion and a second portion in an intersection region. The first portion is in direct contact with the piezoelectric substrate. The second portion is on the first portion such that a space in at least a portion of a central portion of the intersection region in the first portion is provided. A thickness of the first portion is smaller than a thickness of a busbar. A sum of the thickness of the first portion in a portion where the second portion is present and a thickness of the second portion is thicker than the thickness of the first portion in a portion where the second portion is not present.