# US 10,483,941 B2 · Acoustic wave device and method of manufacturing the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,483,941 B2 - Document ID: US10483941B2 - Status: Granted - Kind: B2 - Application number: 15/388,188 - Filed: 2016-12-22 - Published: 2017-07-13 - Granted: 2019-11-19 - Earliest claimed: 2016-01-12 - Assignees: Taiyo Yuden Co., Ltd. - Applicants: Taiyo Yuden Co., Ltd. - Inventors: Yohei Shimizu - Web page: https://patentgrep.com/patent/US10483941B2 ## CPC - H03H 9/02614: {Treatment of substrates, e.g. curved, spherical, cylindrical substrates ensuring closed round-about circuits for the acoustical waves} - H03H 9/02866: {of bulk wave excitation and reflections} - H03H 9/6483: {Ladder SAW filters} - H10N 30/04: Treatments to modify a piezoelectric or electrostrictive property, e.g. polarisation characteristics, vibration characteristics or mode tuning - H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P) - H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR ## Abstract An acoustic wave device includes: a piezoelectric substrate; an IDT that is formed on the piezoelectric substrate and includes a pair of comb-shaped electrodes facing each other, each of the pair of comb-shaped electrodes including an grating electrode that excites an acoustic wave and a bus bar to which the grating electrode is connected; and reforming regions that are located only inside the piezoelectric substrate and arranged at intervals under the IDT, and in which a material of the piezoelectric substrate is reformed. ## Claims ### Claim 1 An acoustic wave device comprising: a single piezoelectric substrate; an IDT that is formed on the single piezoelectric substrate and includes a pair of comb-shaped electrodes facing each other, each of the pair of comb-shaped electrodes including a grating electrode that excites an acoustic wave and a bus bar to which the grating electrode is connected; and reforming regions that are located only inside the single piezoelectric substrate and arranged at intervals each other under the IDT, and in which a material of the single piezoelectric substrate is reformed, wherein the reforming regions have an amorphous structure. ### Claim 2 (depends on 1) The acoustic wave device according to claim 1, wherein the reforming regions are dotted in the single piezoelectric substrate immediately under the IDT. ### Claim 3 (depends on 2) The acoustic wave device according to claim 2, wherein the reforming regions are located along a line in a direction different from a cleavage direction of the single piezoelectric substrate. ### Claim 4 (depends on 2) The acoustic wave device according to claim 2, wherein the reforming regions are located along a line in a different direction from a cleavage direction of the single piezoelectric substrate, and forms a first reforming region group and a second reforming region group located in a direction intersecting the different direction, and the reforming regions of the first reforming region group is located so as not to overlap with the reforming regions of the second reforming region group as viewed from the direction intersecting the different direction. ### Claim 5 (depends on 2) The acoustic wave device according to claim 2, wherein the reforming regions are located at two or more different depths in the single piezoelectric substrate. ### Claim 6 (depends on 2) The acoustic wave device according to claim 2, wherein the single piezoelectric substrate is a rotated Y-cut X-propagation lithium tantalate substrate or a rotated Y-cut X-propagation lithium niobate substrate, and the reforming regions are located along a line in an X-axis direction of a crystal orientation of the single piezoelectric substrate. ### Claim 7 (depends on 1) The acoustic wave device according to claim 1, further comprising: a support substrate of which an upper surface is bonded on a lower surface of the single piezoelectric substrate. ### Claim 8 (depends on 7) The acoustic wave device according to claim 7, wherein the reforming regions are dotted in the single piezoelectric substrate immediately under the IDT, the single piezoelectric substrate has a linear expansion coefficient in a first direction greater than a linear expansion coefficient in a second direction intersecting the first direction, the support substrate has linear expansion coefficients in the first direction and the second direction approximately equal to each other, and the reforming regions are located along a line in the first direction. ### Claim 9 (depends on 8) The acoustic wave device according to claim 8, wherein the single piezoelectric substrate is a rotated Y-cut X-propagation lithium tantalate substrate or a rotated Y-cut X-propagation lithium niobate substrate, the support substrate is a sapphire substrate or a spinel substrate, and the first direction is an X-axis direction of a crystal orientation of the piezoelectric substrate. ### Claim 10 (depends on 1) The acoustic device according to claim 1, wherein the reforming regions are located approximately at a same depth in the single piezoelectric substrate, and an interval between the reforming regions in a plane direction of a surface of the single piezoelectric substrate on which the IDT is formed is less than a wavelength of a bulk wave propagating through an inside of the single piezoelectric substrate. ### Claim 11 (depends on 1) The acoustic wave device according to claim 1, wherein the reforming regions are located along a straight line in a propagation direction of the acoustic wave, forms a first reforming region group and a second reforming region group located side by side as viewed from a direction perpendicular to a surface of the single piezoelectric substrate on which the IDT is formed, and are not located between the first reforming region group and the second reforming region group. ### Claim 12 (depends on 10) The acoustic wave device according to claim 10, wherein the reforming regions are located near a center of the IDT in a direction intersecting the propagation direction of the acoustic wave. ### Claim 13 (depends on 1) The acoustic wave device according to claim 1, wherein the reforming regions are located along a straight line in a direction intersecting a propagation direction of the acoustic wave, forms a first reforming region group and a second reforming region group located side by side as viewed from a direction perpendicular to a surface of the single piezoelectric substrate on which the IDT is formed, and are not located between the first reforming region group and the second reforming region group. ### Claim 14 (depends on 1) The acoustic wave device according to claim 1, wherein the reforming regions are located along a straight line in a direction orthogonal to a propagation direction of the acoustic wave, forms a first reforming region group and a second reforming region group located side by side as viewed from a direction perpendicular to a surface of the single piezoelectric substrate on which the IDT is formed, and are not located between the first reforming region group and the second reforming region group.