JP5136689B2 - Boundary acoustic wave device and manufacturing method thereof - Google Patents

Description

  The present invention relates to a boundary acoustic wave device using a boundary acoustic wave and a manufacturing method thereof, and more particularly, to a three-medium type boundary acoustic wave device and a manufacturing method thereof.

  Conventionally, elastic wave devices have been used for RF filters and IF filters for mobile phones, VCO resonators, television VIF filters, and the like. Conventionally, a surface acoustic wave device using a surface acoustic wave has been generally used as the surface acoustic wave device. However, in recent years, a boundary acoustic wave can be used because it can be made smaller than a surface acoustic wave device. Such boundary acoustic wave devices have come to be used.

  By the way, the surface acoustic wave device uses surface acoustic waves that propagate with concentration of energy on the surface of the medium, so that a dielectric film is formed on the surface of the medium or the surface is etched. Therefore, it is possible to adjust the manufacturing variation of the frequency characteristics such as the resonance frequency and the center frequency relatively easily. On the other hand, the boundary acoustic wave utilized by the boundary acoustic wave device is an acoustic wave that propagates while concentrating energy at the boundary between the media. Therefore, in the boundary acoustic wave device, the boundary acoustic wave is hardly affected by the state of the surface of the medium located in the uppermost layer, and a dielectric film is formed on the surface of the medium located in the uppermost layer, or the surface is etched. However, the frequency characteristics cannot be adjusted. In other words, the boundary acoustic wave device has a problem in that it is difficult to suppress manufacturing variations in frequency characteristics.

  In view of such a problem, for example, in Patent Document 1 below, a three-medium type boundary acoustic wave device in which a second medium and a third medium are stacked in this order on a first medium made of a piezoelectric body. In manufacturing, it is proposed that after the second medium is formed, the frequency characteristics and the like are adjusted by adjusting the thickness of the second medium, and then the third medium is formed.

WO2005 / 093949 A1 publication WO 2006/114930 A1

  By the way, the thickness of the second medium affects the sound speed of the higher-order mode as described in Patent Document 2 above. The sound speed of the higher order mode affects the magnitude of the higher order mode spurious. For this reason, when the thickness of the second medium is different, the magnitude of the higher-order mode spurious is also different.

  Therefore, when the frequency characteristic or the like is adjusted by adjusting the thickness of the second medium, the size of the higher-order mode spurious becomes larger than the desired size depending on the thickness of the adjusted second medium. There is a case. Therefore, there has been a problem that the yield of the boundary acoustic wave device may decrease.

  This invention is made | formed in view of this point, The objective is to provide the elastic boundary wave apparatus which can be produced with a high yield.

  As a result of diligent research, the present inventor has found that the change in the sound speed of the higher mode accompanying the change in the thickness of the second medium can be suppressed by setting the IDT electrode configuration to a predetermined configuration. Invented the invention.

  That is, the boundary acoustic wave device according to the present invention includes a first medium, a second medium, a third medium, and an IDT electrode. The first medium is made of a piezoelectric body. The second medium is formed on the first medium. The second medium is made of a dielectric material. The third medium is formed on the second medium. The third medium is made of a dielectric. The IDT electrode is formed at the boundary between the first medium and the second medium. In the boundary acoustic wave device according to the present invention, the sound velocity of the second medium is slower than the sound velocity of the first and third media. The IDT electrode has a first electrode layer, a second electrode layer, and a third electrode layer. The first electrode layer is formed on the first medium. The second electrode layer is formed on the first electrode layer. The third electrode layer is formed on the second electrode layer. The density of the second electrode layer is lower than the density of the first and third electrode layers. The boundary acoustic wave device according to the present invention satisfies 0.55 <h3 / (h1 + h3) <0.95, where h1 is the thickness of the first electrode layer and h3 is the thickness of the third electrode layer.

  In a specific aspect of the boundary acoustic wave device according to the present invention, the boundary acoustic wave device satisfies 0.70 <h3 / (h1 + h3) <0.95. According to this configuration, the dependence of the magnitude of the higher-order mode spurious on the thickness of the second medium can be more effectively reduced.

  In another specific aspect of the boundary acoustic wave device according to the present invention, the boundary acoustic wave device is configured such that the thickness of the second electrode layer is h2 and the wavelength of the boundary acoustic wave determined by the pitch of the IDT electrode is λ. 0.05 <h2 / λ <0.25. According to this configuration, the effect of reducing the dependency of the size of the higher-order mode spurious on the thickness of the second medium is more suitably exhibited. When h2 / λ is 0.05 or less, it may be difficult to obtain an effect of reducing the dependency of the magnitude of the higher-order mode spurious on the thickness of the second medium. On the other hand, when h2 / λ is 0.25 or more, the electromechanical coupling coefficient becomes small, or the shape accuracy of the second and third media formed on the IDT electrode cannot be obtained sufficiently. There is.

  In another specific aspect of the boundary acoustic wave device according to the present invention, the boundary acoustic wave device is configured such that the thickness of the second medium is H, and the wavelength of the boundary acoustic wave determined by the pitch of the IDT electrode is λ. 0.3 <H / λ <0.7 is satisfied. According to this configuration, the effect that the dependency of the size of the higher-order mode spurious on the thickness of the second medium can be further reduced is more preferably exhibited.

  In still another specific aspect of the boundary acoustic wave device according to the present invention, each of the first and third electrode layers is a metal selected from the group consisting of Au, Pt, W, Ta, Ag, and Cu, or Au , Pt, W, Ta, Ag, and Cu, and an alloy mainly composed of one or more metals selected from the group consisting of.

  In still another specific aspect of the boundary acoustic wave device according to the present invention, the second electrode layer is a metal selected from the group consisting of Al, Ti, Mg, Cr, Fe, Ni, Ag, and Cu, or Al, It consists of the alloy which has as a main component 1 or more types of metals chosen from the group which consists of Ti, Mg, Cr, Fe, Ni, Ag, and Cu.

  In another specific aspect of the boundary acoustic wave device according to the present invention, each of the first and third electrode layers is made of Pt or an alloy containing Pt as a main component, and the second electrode layer is made of Al or Al. It consists of an alloy containing the main component. According to this configuration, it is possible to achieve both low resistance of the IDT electrode and high reliability.

  In another specific aspect of the boundary acoustic wave device according to the present invention, the second medium is made of silicon oxide. According to this configuration, the frequency temperature characteristic can be improved.

In still another specific aspect of the boundary acoustic wave device according to the present invention, the first medium is made of LiNbO ₃ .

In still another specific aspect of the boundary acoustic wave device according to the present invention, the first medium is composed of a 0 ° to 37 ° rotated Y-cut LiNbO ₃ substrate, and the boundary acoustic wave device is an SH type boundary acoustic wave. Is used. In this configuration, high-order mode spurious is likely to occur, and the present invention is particularly suitable.

  In still another specific aspect of the boundary acoustic wave device according to the present invention, the third medium is made of silicon, silicon nitride, silicon carbide, aluminum oxide, or aluminum nitride.

  In still another specific aspect of the boundary acoustic wave device according to the present invention, the third medium is made of silicon nitride. In this configuration, the third medium can be easily processed.

  In another specific aspect of the boundary acoustic wave device according to the present invention, the boundary acoustic wave device further includes a dielectric layer formed between the first medium and the IDT electrode. According to this configuration, surge resistance can be improved.

In another specific aspect of the boundary acoustic wave device according to the present invention, the first medium is made of a LiNbO ₃ substrate, each of the first and third electrode layers is made of Pt, and the second electrode layer is made of It is made of Al, the second medium is made of a SiO ₂ film, and the cut angles of the (h1 + h3), h3 / (h1 + h3), h2, H, and LiNbO ₃ substrates are any of the following first to third groups: It is a combination of.

(First group)
(A1) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 21.5 ° ~ 27 °
(A2) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23 ° ~ 30.5 °
(A3) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° -30 °
(A4) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 21.5 ° ~ 27.5 °
(A5) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23 ° -30 °
(A6) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° ~ 29.5 °
(A7) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.11λ to 0.13λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 21.5 ° ~ 27.5 °
(A8) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.11λ to 0.13λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23 ° -30 °
(A9) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.11λ to 0.13λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° ~ 29 °
(A10) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.07λ to 0.09λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23 ° ~ 28.5 °
(A11) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.07λ to 0.09λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 24 ° ~ 31 °
(A12) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.07λ to 0.09λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° -30 °
(A13) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.09λ to 0.11λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23 ° ~ 29 °
(A14) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.09λ to 0.11λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° to 31 °
(A15) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.09λ to 0.11λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° ~ 29 °
(A16) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.11λ to 0.13λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23 ° ~ 29.5 °
(A17) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.11λ to 0.13λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° ~ 30.5 °
(A18) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.11λ to 0.13λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° ~ 28.5 °
(A19) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.07λ to 0.09λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 30 °
(A20) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.07λ to 0.09λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 31.5 °
(A21) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.07λ to 0.09λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 23 ° -30 °
(A22) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.09λ to 0.11λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 30.5 °
(A23) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.09λ to 0.11λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 31 °
(A24) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.09λ to 0.11λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 23.5 ° ~ 29 °
(A25) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.11λ to 0.13λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 23.5 ° ~ 30.5 °
(A26) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.11λ to 0.13λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 23.5 ° ~ 30.5 °
(A27) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.11λ to 0.13λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 23 ° ~ 28 °

(Second group)
(C1) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.05λ to 0.07λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 22 ° ~ 28.5 °
(C2) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.05λ to 0.07λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° -30 °
(C3) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.05λ to 0.07λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° ~ 28 °
(C4) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 22.5 ° ~ 29 °
(C5) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24 ° ~ 29.5 °
(C6) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24.5 ° ~ 26.5 °
(C7) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23 ° ~ 29 °
(C8) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24.5 ° ~ 29 °
(C9) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° ~ 26.5 °
(C10) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.05λ to 0.07λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 22.5 ° ~ 28.5 °
(C11) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.05λ to 0.07λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° -30 °
(C12) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.05λ to 0.07λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° ~ 27 °
(C13) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23 ° ~ 29 °
(C14) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24 ° ~ 29 °
(C15) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° ~ 26 °
(C16) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23 ° ~ 29.5 °
(C17) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 25 ° ~ 28.5 °
(C18) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 22 ° ~ 26.5 °
(C19) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.05λ to 0.07λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23 ° ~ 29 °
(C20) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.05λ to 0.07λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24 ° ~ 29.5 °
(C21) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.05λ to 0.07λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24 ° ~ 26.5 °
(C22) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23 ° ~ 29.5 °
(C23) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24.5 ° ~ 28.5 °
(C24) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 22.5 ° ~ 26 °
(C25) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° ~ 29.5 °
(C26) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24.5 ° ~ 27 °
(C27) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 21 ° ~ 27 °
(C28) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.05λ to 0.07λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° -30 °
(C29) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.05λ to 0.07λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 24 ° ~ 30.5 °
(C30) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.05λ to 0.07λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° ~ 28 °
(C31) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.07λ to 0.09λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° -30 °
(C32) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.07λ to 0.09λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 24 ° ~ 29.5 °
(C33) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.07λ to 0.09λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 24 ° ~ 25.5 °
(C34) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.09λ to 0.11λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° -30 °
(C35) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.09λ to 0.11λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 24 ° ~ 28.5 °
(C36) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.09λ to 0.11λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 22 ° ~ 26 °
(C37) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.05λ to 0.07λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° -30 °
(C38) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.05λ to 0.07λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° -30 °
(C39) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.05λ to 0.07λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° ~ 27 °
(C40) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° -30 °
(C41) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 24 ° ~ 29 °
(C42) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 22.5 ° ~ 25.5 °
(C43) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 24 ° ~ 30 °
(C44) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 25 ° ~ 27 °
(C45) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 20.5 ° ~ 26 °
(C46) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.05λ to 0.07λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° -30 °
(C47) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.05λ to 0.07λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 24 ° ~ 29.5 °
(C48) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.05λ to 0.07λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 24 ° ~ 25.5 °
(C49) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° -30 °
(C50) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 24.5 ° ~ 28 °
(C51) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 21 ° ~ 25.5 °
(C52) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 24 ° ~ 30 °
(C53) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 24 ° ~ 26.5 °
(C54) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 19.5 ° ~ 25.5 °
(C55) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.05λ to 0.07λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 31 °
(C56) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.05λ to 0.07λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 31 °
(C57) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.05λ to 0.07λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 23 ° ~ 27.5 °
(C58) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.07λ to 0.09λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 3 °
(C59) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.07λ to 0.09λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 29 °
(C60) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.07λ to 0.09λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 23 ° ~ 26.5 °
(C61) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.09λ to 0.11λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 30.5 °
(C62) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.09λ to 0.11λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 27.5 °
(C63) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.09λ to 0.11λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 20.5 ° -25 °
(C64) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.05λ to 0.07λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 31 °
(C65) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.05λ to 0.07λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 30 °
(C66) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.05λ to 0.07λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 23 ° ~ 26.5 °
(C67) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 31 °
(C68) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 28.5 °
(C69) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 21.5 ° ~ 25 °
(C70) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 30 °
(C71) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 22 ° ~ 26 °
(C72) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 19 ° ~ 25 °
(C73) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.05λ to 0.07λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 31 °
(C74) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.05λ to 0.07λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 29.5 °
(C75) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.05λ to 0.07λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 23.5 ° ~ 26 °
(C76) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 30.5 °
(C77) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 27 °
(C78) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 20 ° ~ 25 °
(C79) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24.5 ° -30 °
(C80) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 23 ° ~ 26 °
(C81) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 18 ° ~ 24.5 °

(Third group)
(D1) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 19.5 ° ~ 25 °
(D2) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 23.5 ° ~ 29.5 °
(D3) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 25.5 ° ~ 28.5 °
(D4) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 19 ° ~ 25 °
(D5) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 23.5 ° ~ 29.5 °
(D6) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 25.5 ° ~ 28 °
(D7) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.11λ to 0.13λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 18.5 ° ~ 24 °
(D8) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.11λ to 0.13λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 23.5 ° ~ 29.5 °
(D9) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.11λ to 0.13λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 27 ° ~ 29 °
(D10) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 20 ° ~ 26 °
(D11) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 24 ° ~ 29.5 °
(D12) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 25 ° ~ 27.5 °
(D13) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 20 ° ~ 26 °
(D14) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 24.5 ° -30 °
(D15) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 26 ° ~ 29.5 °
(D16) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.11λ to 0.13λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 19.5 ° ~ 25.5 °
(D17) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.11λ to 0.13λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 25 ° -30 °
(D18) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.11λ to 0.13λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 26 ° ~ 31 °
(D19) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.07λ to 0.09λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 20.5 ° ~ 21.5 °
(D20) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.07λ to 0.09λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 25 ° -30 °
(D21) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.07λ to 0.09λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 25.5 ° ~ 29 °
(D22) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.09λ to 0.11λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 21 ° ~ 27 °
(D23) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.09λ to 0.11λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 26 ° -30 °
(D24) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.09λ to 0.11λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 25 ° ~ 30.5 °
(D25) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.11λ to 0.13λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 21 ° ~ 26.5 °
(D26) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.11λ to 0.13λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 26.5 ° -30 °
(D27) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.11λ to 0.13λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 25.5 ° ~ 32 °
(D28) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 21.5 ° ~ 28 °
(D29) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 24 ° ~ 29.5 °
(D30) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 25.5 ° ~ 26.5 °
(D31) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 21.5 ° ~ 28 °
(D32) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 24.5 ° ~ 29.5 °
(D33) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 24 ° ~ 28 °
(D34) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.11λ to 0.13λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 22 ° ~ 28 °
(D35) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.11λ to 0.13λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 25.5 ° ~ 29 °
(D36) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.11λ to 0.13λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 23.5 ° ~ 28.5 °
(D37) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 22 ° ~ 28.5 °
(D38) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 24.5 ° ~ 29.5 °
(D39) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 24 ° ~ 27 °
(D40) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 22.5 ° ~ 28.5 °
(D41) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 25 ° ~ 29 °
(D42) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 23 ° ~ 28.5 °
(D43) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.11λ to 0.13λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 23 ° ~ 29 °
(D44) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.11λ to 0.13λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 25 ° ~ 28 °
(D45) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.11λ to 0.13λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 23 ° ~ 29.5 °
(D46) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.07λ to 0.09λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 22.5 ° ~ 29 °
(D47) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.07λ to 0.09λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 25 ° ~ 29 °
(D48) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.07λ to 0.09λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 23 ° ~ 28 °
(D49) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.09λ to 0.11λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 23.5 ° ~ 29 °
(D50) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.09λ to 0.11λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 25 ° ~ 28 °
(D51) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.09λ to 0.11λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 22 ° ~ 28.5 °
(D52) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.11λ to 0.13λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 24 ° ~ 29.5 °
(D53) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.11λ to 0.13λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 26 ° -30 °
(D54) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.11λ to 0.13λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 22 ° ~ 30 °
(D55) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 22.5 ° ~ 29 °
(D56) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24 ° ~ 29 °
(D57) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° ~ 26 °
(D58) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23 ° ~ 29.5 °
(D59) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 25 ° ~ 28.5 °
(D60) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 22 ° ~ 27 °
(D61) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.11λ to 0.13λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° ~ 29.5 °
(D62) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.11λ to 0.13λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 25 ° ~ 28 °
(D63) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.11λ to 0.13λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 21 ° ~ 27.5 °
(D64) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23 ° ~ 29.5 °
(D65) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24.5 ° ~ 28.5 °
(D66) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 22.5 ° ~ 26.5 °
(D67) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° ~ 29.5 °
(D68) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24.5 ° ~ 28.5 °
(D69) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 21 ° ~ 27 °
(D70) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.11λ to 0.13λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24 ° ~ 30 °
(D71) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.11λ to 0.13λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24 ° ~ 28 °
(D72) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.11λ to 0.13λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 20 ° ~ 27.5 °
(D73) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° ~ 29.5 °
(D74) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 25 ° ~ 28 °
(D75) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 21.5 ° ~ 26.5 °
(D76) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24 ° ~ 29.5 °
(D77) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24.5 ° ~ 28 °
(D78) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 20 ° ~ 27 °
(D79) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.11λ to 0.13λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 25 ° ~ 29.5 °
(D80) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.11λ to 0.13λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° ~ 29 °
(D81) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.11λ to 0.13λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 19 ° ~ 27.5 °

  The method for manufacturing a boundary acoustic wave device according to the present invention is a method for manufacturing the boundary acoustic wave device according to the present invention, wherein the third medium is adjusted after adjusting the frequency characteristics by adjusting the thickness of the second medium. Form.

  In the present invention, the boundary acoustic wave device is a three-medium boundary acoustic wave device having first to third media, and the IDT electrode includes first and third electrode layers, and first and third electrodes. A second electrode layer located between the electrode layers and having a lower density than the first and third electrode layers, the thickness of the first electrode layer being h1, and the third electrode layer When the thickness of h3 is h3, 0.55 <h3 / (h1 + h3) <0.95. For this reason, the dependence of the sound speed of the higher-order mode on the thickness of the second medium is low. That is, even if the thickness of the second medium changes, the sound speed of the higher-order mode hardly changes, and the magnitude of the higher-order mode spurious does not easily change as the thickness of the second medium changes. Therefore, even when the thickness of the second medium is adjusted in order to adjust the frequency characteristics and the like, it is effectively suppressed that the size of the higher-order mode spurious becomes larger than the desired size. Therefore, it is difficult for defects relating to frequency characteristics and the like to occur, and defects relating to the magnitude of higher-order mode spurs are less likely to occur. As a result, boundary acoustic wave devices can be manufactured with a high yield.

FIG. 1 is a schematic cross-sectional view of a boundary acoustic wave device according to a first embodiment. FIG. 2 is a graph showing the relationship between the thickness (H) of the second medium and the sound speed of the higher-order mode when h3 / (h1 + h3) is 0.30. FIG. 3 is a graph showing the relationship between the thickness (H) of the second medium and the sound speed of the higher-order mode when h3 / (h1 + h3) is 0.55. FIG. 4 is a graph showing the relationship between the thickness (H) of the second medium and the sound speed of the higher-order mode when h3 / (h1 + h3) is 0.70. FIG. 5 is a graph showing the relationship between the thickness (H) of the second medium and the sound speed of the higher-order mode when h3 / (h1 + h3) is 0.90. FIG. 6 is a graph showing the relationship between the thickness (H) of the second medium and the sound speed of the higher-order mode when h3 / (h1 + h3) is 0.95. FIG. 7 shows the thickness (H) of the second medium 12 and the sound speed of the higher-order mode when the thickness (h2) of the second electrode layer 22 is 0.07λ and h3 / (h1 + h3) is 0.30. It is a graph showing the relationship. FIG. 8 shows the thickness (H) of the second medium 12 and the sound speed of the higher-order mode when the thickness (h2) of the second electrode layer 22 is 0.07λ and h3 / (h1 + h3) is 0.55. It is a graph showing the relationship. FIG. 9 shows the thickness (H) of the second medium 12 and the sound speed of the higher-order mode when the thickness (h2) of the second electrode layer 22 is 0.07λ and h3 / (h1 + h3) is 0.70. It is a graph showing the relationship. FIG. 10 shows the thickness (H) of the second medium 12 and the sound speed of the higher-order mode when the thickness (h2) of the second electrode layer 22 is 0.07λ and h3 / (h1 + h3) is 0.90. It is a graph showing the relationship. FIG. 11 shows the thickness (H) of the second medium 12 and the sound speed of the higher-order mode when the thickness (h2) of the second electrode layer 22 is 0.07λ and h3 / (h1 + h3) is 0.95. It is a graph showing the relationship. FIG. 12 shows the thickness (H) of the second medium 12 and the sound speed of the higher-order mode when the thickness (h2) of the second electrode layer 22 is 0.20λ and h3 / (h1 + h3) is 0.30. It is a graph showing the relationship. FIG. 13 shows the thickness (H) of the second medium 12 and the sound speed of the higher-order mode when the thickness (h2) of the second electrode layer 22 is 0.20λ and h3 / (h1 + h3) is 0.55. It is a graph showing the relationship. FIG. 14 shows the thickness (H) of the second medium 12 and the sound speed of the higher-order mode when the thickness (h2) of the second electrode layer 22 is 0.20λ and h3 / (h1 + h3) is 0.70. It is a graph showing the relationship. FIG. 15 shows the thickness (H) of the second medium 12 and the sound speed of the higher-order mode when the thickness (h2) of the second electrode layer 22 is 0.20λ and h3 / (h1 + h3) is 0.90. It is a graph showing the relationship. FIG. 16 shows the thickness (H) of the second medium 12 and the sound speed of the higher-order mode when the thickness (h2) of the second electrode layer 22 is 0.20λ and h3 / (h1 + h3) is 0.95. It is a graph showing the relationship. FIG. 17 shows that the total thickness (h1 + h3) of the first and third electrode layers 21 and 23 is 0.04λ, the thickness (h2) of the second electrode layer 22 is 0.14λ, and h3 / (h1 + h3). 6 is a graph showing the relationship between the thickness (H) of the second medium 12 and the sound speed of a higher-order mode when is 0.30. In FIG. 18, the total thickness (h1 + h3) of the first and third electrode layers 21 and 23 is 0.04λ, the thickness (h2) of the second electrode layer 22 is 0.14λ, and h3 / (h1 + h3). 6 is a graph showing the relationship between the thickness (H) of the second medium 12 and the sound speed of a higher-order mode when is 0.55. In FIG. 19, the total thickness (h1 + h3) of the first and third electrode layers 21 and 23 is 0.04λ, the thickness (h2) of the second electrode layer 22 is 0.14λ, and h3 / (h1 + h3). 6 is a graph showing the relationship between the thickness (H) of the second medium 12 and the sound speed of the higher-order mode when is 0.70. In FIG. 20, the total thickness (h1 + h3) of the first and third electrode layers 21 and 23 is 0.04λ, the thickness (h2) of the second electrode layer 22 is 0.14λ, and h3 / (h1 + h3). 6 is a graph showing the relationship between the thickness (H) of the second medium 12 and the sound speed of a higher-order mode when is 0.90. FIG. 21 shows that the total thickness (h1 + h3) of the first and third electrode layers 21, 23 is 0.04λ, the thickness (h2) of the second electrode layer 22 is 0.14λ, and h3 / (h1 + h3). 6 is a graph showing the relationship between the thickness (H) of the second medium 12 and the sound speed of a higher-order mode when is 0.95. FIG. 22 shows the thickness of the second medium 12 when the first electrode layer 21: Au / second electrode layer: Al / third electrode layer: Au and h3 / (h1 + h3) is 0.30. It is a graph showing the relationship between (H) and the sound speed of a higher-order mode. FIG. 23 shows the thickness of the second medium 12 when the first electrode layer 21: Au / second electrode layer: Al / third electrode layer: Au and h3 / (h1 + h3) is 0.55. It is a graph showing the relationship between (H) and the sound speed of a higher-order mode. FIG. 24 shows the thickness of the second medium 12 when the first electrode layer 21: Au / second electrode layer: Al / third electrode layer: Au and h3 / (h1 + h3) is 0.70. It is a graph showing the relationship between (H) and the sound speed of a higher-order mode. FIG. 25 shows the thickness of the second medium 12 when the first electrode layer 21: Au / second electrode layer: Al / third electrode layer: Au and h3 / (h1 + h3) is 0.90. It is a graph showing the relationship between (H) and the sound speed of a higher-order mode. FIG. 26 shows the thickness of the second medium 12 when the first electrode layer 21: Au / second electrode layer: Al / third electrode layer: Au and h3 / (h1 + h3) is 0.95. It is a graph showing the relationship between (H) and the sound speed of a higher-order mode. FIG. 27 shows the thickness of the second medium 12 when the first electrode layer 21: W / second electrode layer: Al / third electrode layer: W and h3 / (h1 + h3) is 0.30. It is a graph showing the relationship between (H) and the sound speed of a higher-order mode. FIG. 28 shows the thickness of the second medium 12 when the first electrode layer 21: W / second electrode layer: Al / third electrode layer: W and h3 / (h1 + h3) is 0.55. It is a graph showing the relationship between (H) and the sound speed of a higher-order mode. FIG. 29 shows the thickness of the second medium 12 when the first electrode layer 21: W / second electrode layer: Al / third electrode layer: W and h3 / (h1 + h3) is 0.70. It is a graph showing the relationship between (H) and the sound speed of a higher-order mode. FIG. 30 shows the thickness of the second medium 12 when the first electrode layer 21: W / second electrode layer: Al / third electrode layer: W and h3 / (h1 + h3) is 0.90. It is a graph showing the relationship between (H) and the sound speed of a higher-order mode. FIG. 31 shows the thickness of the second medium 12 when the first electrode layer 21: W / second electrode layer: Al / third electrode layer: W and h3 / (h1 + h3) is 0.95. It is a graph showing the relationship between (H) and the sound speed of a higher-order mode. FIG. 32 shows the thickness of the second medium 12 when the first electrode layer 21: Ta / second electrode layer: Al / third electrode layer: Ta and h3 / (h1 + h3) is 0.30. It is a graph showing the relationship between (H) and the sound speed of a higher-order mode. FIG. 33 shows the thickness of the second medium 12 when the first electrode layer 21: Ta / second electrode layer: Al / third electrode layer: Ta and h3 / (h1 + h3) is 0.55. It is a graph showing the relationship between (H) and the sound speed of a higher-order mode. FIG. 34 shows the thickness of the second medium 12 when the first electrode layer 21: Ta / second electrode layer: Al / third electrode layer: Ta and h3 / (h1 + h3) is 0.70. It is a graph showing the relationship between (H) and the sound speed of a higher-order mode. FIG. 35 shows the thickness of the second medium 12 when the first electrode layer 21: Ta / second electrode layer: Al / third electrode layer: Ta and h3 / (h1 + h3) is 0.90. It is a graph showing the relationship between (H) and the sound speed of a higher-order mode. FIG. 36 shows the thickness of the second medium 12 when the first electrode layer 21: Ta / second electrode layer: Al / third electrode layer: Ta and h3 / (h1 + h3) is 0.95. It is a graph showing the relationship between (H) and the sound speed of a higher-order mode. FIG. 37 shows the thickness of the second medium 12 when the first electrode layer 21: Cu / second electrode layer: Al / third electrode layer: Cu and h3 / (h1 + h3) is 0.30. It is a graph showing the relationship between (H) and the sound speed of a higher-order mode. FIG. 38 shows the thickness of the second medium 12 when the first electrode layer 21: Cu / second electrode layer: Al / third electrode layer: Cu and h3 / (h1 + h3) is 0.55. It is a graph showing the relationship between (H) and the sound speed of a higher-order mode. FIG. 39 shows the thickness of the second medium 12 when the first electrode layer 21: Cu / second electrode layer: Al / third electrode layer: Cu and h3 / (h1 + h3) is 0.70. It is a graph showing the relationship between (H) and the sound speed of a higher-order mode. FIG. 40 shows the thickness of the second medium 12 when the first electrode layer 21: Cu / second electrode layer: Al / third electrode layer: Cu and h3 / (h1 + h3) is 0.90. It is a graph showing the relationship between (H) and the sound speed of a higher-order mode. FIG. 41 shows the thickness of the second medium 12 when the first electrode layer 21: Cu / second electrode layer: Al / third electrode layer: Cu and h3 / (h1 + h3) is 0.95. It is a graph showing the relationship between (H) and the sound speed of a higher-order mode. FIG. 42 shows the thickness of the second medium 12 when the first electrode layer 21: Pt / second electrode layer: Cu / third electrode layer: Pt and h3 / (h1 + h3) is 0.30. It is a graph showing the relationship between (H) and the sound speed of a higher-order mode. FIG. 43 shows the thickness of the second medium 12 when the first electrode layer 21: Pt / second electrode layer: Cu / third electrode layer: Pt and h3 / (h1 + h3) is 0.55. It is a graph showing the relationship between (H) and the sound speed of a higher-order mode. FIG. 44 shows the thickness of the second medium 12 when the first electrode layer 21: Pt / second electrode layer: Cu / third electrode layer: Pt and h3 / (h1 + h3) is 0.70. It is a graph showing the relationship between (H) and the sound speed of a higher-order mode. FIG. 45 shows the thickness of the second medium 12 when the first electrode layer 21: Pt / second electrode layer: Cu / third electrode layer: Pt and h3 / (h1 + h3) is 0.90. It is a graph showing the relationship between (H) and the sound speed of a higher-order mode. FIG. 46 shows the thickness of the second medium 12 when the first electrode layer 21: Pt / second electrode layer: Cu / third electrode layer: Pt and h3 / (h1 + h3) is 0.95. It is a graph showing the relationship between (H) and the sound speed of a higher-order mode. FIG. 47 is a graph showing impedance (Z) characteristics when a 37 ° Y-cut LiNbO ₃ substrate is used as the first medium. FIG. 48 is a graph showing phase characteristics when a 37 ° Y-cut LiNbO ₃ substrate is used as the first medium. FIG. 49 is a graph showing impedance (Z) characteristics when a 0 ° Y-cut LiNbO ₃ substrate is used as the first medium. FIG. 50 is a graph showing phase characteristics when a 0 ° Y-cut LiNbO ₃ substrate is used as the first medium. FIG. 51 is a schematic cross-sectional view of a boundary acoustic wave device according to the second embodiment. FIG. 52 is a schematic cross-sectional view of an IDT electrode in a boundary acoustic wave device according to a third embodiment. FIG. 53 is a schematic cross-sectional view of an IDT electrode in a boundary acoustic wave device according to a fourth embodiment. FIG. 54 is a schematic cross-sectional view of a boundary acoustic wave device according to a fifth embodiment. In FIG. 55, the SiO ₂ film thickness (H) is 0.40λ, the ratio (h3 / (h1 + h3)) to the total Pt film thickness of the first Pt film is 0.45, and the Al film thickness (h2). Is the relationship between the cut angle of LiNbO ₃ and the SV wave ratio band when the total Pt film thickness (h1 + h3) is 0.02λ, 0.025λ, or 0.03λ. In FIG. 56, the SiO ₂ film thickness is 0.40λ, the ratio of the first Pt film to the total Pt film thickness is 0.45, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 57, the SiO ₂ film thickness is 0.40λ, the ratio of the first Pt film to the total Pt film thickness is 0.45, the Al film thickness is 0.12λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 58, the SiO ₂ film thickness is 0.40λ, the ratio of the first Pt film to the total Pt film thickness is 0.50, the Al film thickness is 0.08λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 59, the SiO ₂ film thickness is 0.40λ, the ratio of the first Pt film to the total Pt film thickness is 0.50, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 60, the SiO ₂ film thickness is 0.40λ, the ratio of the first Pt film to the total Pt film thickness is 0.50, the Al film thickness is 0.12λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 61, the SiO ₂ film thickness is 0.40λ, the ratio of the first Pt film to the total Pt film thickness is 0.55, the Al film thickness is 0.08λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 62, the SiO ₂ film thickness is 0.40λ, the ratio of the first Pt film to the total Pt film thickness is 0.55, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 63, the SiO ₂ film thickness is 0.40λ, the ratio of the first Pt film to the total Pt film thickness is 0.55, the Al film thickness is 0.12λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 64, the SiO ₂ film thickness is 0.45λ, the ratio of the first Pt film to the total Pt film thickness is 0.45, the Al film thickness is 0.08λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 65, the SiO ₂ film thickness is 0.45λ, the ratio of the first Pt film to the total Pt film thickness is 0.45, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 66, the SiO ₂ film thickness is 0.45λ, the ratio of the first Pt film to the total Pt film thickness is 0.45, the Al film thickness is 0.12λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 67, the SiO ₂ film thickness is 0.45λ, the ratio of the first Pt film to the total Pt film thickness is 0.50, the Al film thickness is 0.08λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 68, the SiO ₂ film thickness is 0.45λ, the ratio of the first Pt film to the total Pt film thickness is 0.50, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 69, the SiO ₂ film thickness is 0.45λ, the ratio of the first Pt film to the total Pt film thickness is 0.50, the Al film thickness is 0.12λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 70, the SiO ₂ film thickness is 0.45λ, the ratio of the first Pt film to the total Pt film thickness is 0.55, the Al film thickness is 0.08λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 71, the SiO ₂ film thickness is 0.45λ, the ratio of the first Pt film to the total Pt film thickness is 0.55, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 72, the SiO ₂ film thickness is 0.45λ, the ratio of the first Pt film to the total Pt film thickness is 0.55, the Al film thickness is 0.12λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 73, the SiO ₂ film thickness is 0.50λ, the ratio of the first Pt film to the total Pt film thickness is 0.45, the Al film thickness is 0.08λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 74, the SiO ₂ film thickness is 0.50λ, the ratio of the first Pt film to the total Pt film thickness is 0.45, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 75, the SiO ₂ film thickness is 0.50λ, the ratio of the first Pt film to the total Pt film thickness is 0.45, the Al film thickness is 0.12λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 76, the SiO ₂ film thickness is 0.50λ, the ratio of the first Pt film to the total Pt film thickness is 0.50, the Al film thickness is 0.08λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 77, the SiO ₂ film thickness is 0.50λ, the ratio of the first Pt film to the total Pt film thickness is 0.50, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 78, the SiO ₂ film thickness is 0.50λ, the ratio of the first Pt film to the total Pt film thickness is 0.50, the Al film thickness is 0.12λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 79, the SiO ₂ film thickness is 0.50λ, the ratio of the first Pt film to the total Pt film thickness is 0.55, the Al film thickness is 0.08λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 80, the SiO ₂ film thickness is 0.50λ, the ratio of the first Pt film to the total Pt film thickness is 0.55, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 81, the SiO ₂ film thickness is 0.50λ, the ratio of the first Pt film to the total Pt film thickness is 0.55, the Al film thickness is 0.12λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 82, the SiO ₂ film thickness is 0.40λ, the ratio of the first Pt film to the total Pt film thickness is 0.75, the Al film thickness is 0.06λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 83, the SiO ₂ film thickness is 0.40λ, the ratio of the first Pt film to the total Pt film thickness is 0.75, the Al film thickness is 0.08λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 84, the SiO ₂ film thickness is 0.40λ, the ratio of the first Pt film to the total Pt film thickness is 0.75, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 85, the SiO ₂ film thickness is 0.40λ, the ratio of the first Pt film to the total Pt film thickness is 0.80, the Al film thickness is 0.06λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 86, the SiO ₂ film thickness is 0.40λ, the ratio of the first Pt film to the total Pt film thickness is 0.80, the Al film thickness is 0.08λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 87, the SiO ₂ film thickness is 0.40λ, the ratio of the first Pt film to the total Pt film thickness is 0.80, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 88, the SiO ₂ film thickness is 0.40λ, the ratio of the first Pt film to the total Pt film thickness is 0.85, the Al film thickness is 0.06λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 89, the SiO ₂ film thickness is 0.40λ, the ratio of the first Pt film to the total Pt film thickness is 0.85, the Al film thickness is 0.08λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 90, the SiO ₂ film thickness is 0.40λ, the ratio of the first Pt film to the total Pt film thickness is 0.85, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 91, the SiO ₂ film thickness is 0.45λ, the ratio of the first Pt film to the total Pt film thickness is 0.75, the Al film thickness is 0.06λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 92, the SiO ₂ film thickness is 0.45λ, the ratio of the first Pt film to the total Pt film thickness is 0.75, the Al film thickness is 0.08λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 93, the SiO ₂ film thickness is 0.45λ, the ratio of the first Pt film to the total Pt film thickness is 0.75, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 94, the SiO ₂ film thickness is 0.45λ, the ratio of the first Pt film to the total Pt film thickness is 0.80, the Al film thickness is 0.06λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 95, the SiO ₂ film thickness is 0.45λ, the ratio of the first Pt film to the total Pt film thickness is 0.80, the Al film thickness is 0.08λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 96, the SiO ₂ film thickness is 0.45λ, the ratio of the first Pt film to the total Pt film thickness is 0.80, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 97, the SiO ₂ film thickness is 0.45λ, the ratio of the first Pt film to the total Pt film thickness is 0.85, the Al film thickness is 0.06λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 98, the SiO ₂ film thickness is 0.45λ, the ratio of the first Pt film to the total Pt film thickness is 0.85, the Al film thickness is 0.08λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 99, the SiO ₂ film thickness is 0.45λ, the ratio of the first Pt film to the total Pt film thickness is 0.85, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 100, the SiO ₂ film thickness is 0.50λ, the ratio of the first Pt film to the total Pt film thickness is 0.75, the Al film thickness is 0.06λ, and the total Pt film thickness is 0. It is a figure which shows the relationship between the cut angle in the case of 0.02λ, 0.025λ, or 0.03λ and the SV wave ratio band. In FIG. 101, the SiO ₂ film thickness is 0.50λ, the ratio of the first Pt film to the total Pt film thickness is 0.75, the Al film thickness is 0.08λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 102, the SiO ₂ film thickness is 0.50λ, the ratio of the first Pt film to the total Pt film thickness is 0.75, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 103, the SiO ₂ film thickness is 0.50λ, the ratio of the first Pt film to the total Pt film thickness is 0.80, the Al film thickness is 0.06λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 104, the SiO ₂ film thickness is 0.50λ, the ratio of the first Pt film to the total Pt film thickness is 0.80, the Al film thickness is 0.08λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 105, the SiO ₂ film thickness is 0.50λ, the ratio of the first Pt film to the total Pt film thickness is 0.80, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 106, the SiO ₂ film thickness is 0.50λ, the ratio of the first Pt film to the total Pt film thickness is 0.85, the Al film thickness is 0.06λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 107, the SiO ₂ film thickness is 0.50λ, the ratio of the first Pt film to the total Pt film thickness is 0.85, the Al film thickness is 0.08λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. FIG. 108 shows that the SiO ₂ film thickness is 0.50λ, the ratio of the first Pt film to the total Pt film thickness is 0.85, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. FIG. 109 shows that the SiO ₂ film thickness is 0.30λ, the ratio of the first Pt film to the total Pt film thickness is 0.80, the Al film thickness is 0.08λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 110, the SiO ₂ film thickness is 0.30λ, the ratio of the first Pt film to the total Pt film thickness is 0.80, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 111, the SiO ₂ film thickness is 0.30λ, the ratio of the first Pt film to the total Pt film thickness is 0.80, the Al film thickness is 0.12λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 112, the SiO ₂ film thickness is 0.30λ, the ratio of the first Pt film to the total Pt film thickness is 0.85, the Al film thickness is 0.08λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 113, the SiO ₂ film thickness is 0.30λ, the ratio of the first Pt film to the total Pt film thickness is 0.85, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 114, the SiO ₂ film thickness is 0.30λ, the ratio of the first Pt film to the total Pt film thickness is 0.85, the Al film thickness is 0.12λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 115, the SiO ₂ film thickness is 0.30λ, the ratio of the first Pt film to the total Pt film thickness is 0.90, the Al film thickness is 0.08λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 116, the SiO ₂ film thickness is 0.30λ, the ratio of the first Pt film to the total Pt film thickness is 0.90, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 117, the SiO ₂ film thickness is 0.30λ, the ratio of the first Pt film to the total Pt film thickness is 0.90, the Al film thickness is 0.12λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 118, the SiO ₂ film thickness is 0.35λ, the ratio of the first Pt film to the total Pt film thickness is 0.80, the Al film thickness is 0.08λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. FIG. 119 shows that the SiO ₂ film thickness is 0.35λ, the ratio of the first Pt film to the total Pt film thickness is 0.80, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 120, the SiO ₂ film thickness is 0.35λ, the ratio of the first Pt film to the total Pt film thickness is 0.80, the Al film thickness is 0.12λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 121, the SiO ₂ film thickness is 0.35λ, the ratio of the first Pt film to the total Pt film thickness is 0.85, the Al film thickness is 0.08λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 122, the SiO ₂ film thickness is 0.35λ, the ratio of the first Pt film to the total Pt film thickness is 0.85, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 123, the SiO ₂ film thickness is 0.35λ, the ratio of the first Pt film to the total Pt film thickness is 0.85, the Al film thickness is 0.12λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 124, the SiO ₂ film thickness is 0.35λ, the ratio of the first Pt film to the total Pt film thickness is 0.90, the Al film thickness is 0.08λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 125, the SiO ₂ film thickness is 0.35λ, the ratio of the first Pt film to the total Pt film thickness is 0.90, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 126, the SiO ₂ film thickness is 0.35λ, the ratio of the first Pt film to the total Pt film thickness is 0.90, the Al film thickness is 0.12λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 127, the SiO ₂ film thickness is 0.40λ, the ratio of the first Pt film to the total Pt film thickness is 0.80, the Al film thickness is 0.08λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 128, the SiO ₂ film thickness is 0.40λ, the ratio of the first Pt film to the total Pt film thickness is 0.80, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 129, the SiO ₂ film thickness is 0.40λ, the ratio of the first Pt film to the total Pt film thickness is 0.80, the Al film thickness is 0.12λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 130, the SiO ₂ film thickness is 0.40λ, the ratio of the first Pt film to the total Pt film thickness is 0.85, the Al film thickness is 0.08λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 131, the SiO ₂ film thickness is 0.40λ, the ratio of the first Pt film to the total Pt film thickness is 0.85, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 132, the SiO ₂ film thickness is 0.40λ, the ratio of the first Pt film to the total Pt film thickness is 0.85, the Al film thickness is 0.12λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 133, the SiO ₂ film thickness is 0.40λ, the ratio of the first Pt film to the total Pt film thickness is 0.90, the Al film thickness is 0.08λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 134, the SiO ₂ film thickness is 0.40λ, the ratio of the first Pt film to the total Pt film thickness is 0.90, the Al film thickness is 0.10λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. In FIG. 135, the SiO ₂ film thickness is 0.40λ, the ratio of the first Pt film to the total Pt film thickness is 0.90, the Al film thickness is 0.12λ, and the total Pt film thickness is 0. .02Ramuda, is a diagram showing a relationship between a cut angle and SV wave ratio band of LiNbO ₃ in the case of 0.025λ or 0.03. FIG. 136 is a diagram showing the relationship between the thickness of the Al film as the fourth electrode layer and the frequency temperature coefficient TCF in the seventh embodiment of the present invention.

(First embodiment)
Hereinafter, an example of a preferable embodiment in which the present invention is implemented will be described with reference to the boundary acoustic wave device 1 shown in FIG. The type of boundary acoustic wave device 1 is not particularly limited, and the boundary acoustic wave device 1 may be, for example, a boundary acoustic wave resonator or a boundary acoustic wave filter device.

As shown in FIG. 1, the boundary acoustic wave device 1 includes a first medium 11, a second medium 12, and a third medium 13. The first medium 11 is made of a piezoelectric body. The type of the piezoelectric body that constitutes the first medium 11 is not particularly limited. The first medium 11 can be composed of, for example, a LiNbO ₃ substrate such as a 0 ° to 37 ° rotated Y-cut LiNbO ₃ substrate, a LiTaO ₃ substrate, or the like.

A second medium 12 is formed on the first medium 11. Furthermore, a third medium 13 is formed on the second medium 12. Each of the second and third media 12 and 13 is made of a dielectric. The forming materials of the second and third media 12 and 13 are selected so that the sound speed of the second medium 12 is slower than the sound speed of the first and third media 11 and 13. For example, the second medium 12 is made of silicon oxide such as SiO ₂ , and the third medium 13 is silicon, silicon nitride, silicon oxynitride, silicon carbide, aluminum oxide, aluminum nitride, diamond-like carbon (DLC). Or the like. Thus, when the second medium 12 is made of silicon oxide, the frequency temperature characteristics can be improved. The third medium 13 is more preferably made of silicon nitride such as SiN. In this case, it is because processing becomes easy.

  The thicknesses of the second and third media 12 and 13 are not particularly limited. For example, the thickness of the second medium 12 is preferably in the range of 0.3λ to 0.7λ, where λ is the wavelength of the boundary acoustic wave generated in the IDT electrode 20 described later. In other words, if the thickness of the second medium 12 is H, it is preferable that 0.3 <H / λ <0.7 is satisfied. On the other hand, the thickness of the third medium 13 is preferably such that the amount of displacement of the elastic wave on the surface of the third medium 13 is substantially zero. Specifically, the thickness of the third medium 13 is preferably in the range of 0.6λ to 2λ, for example. Similarly, the thickness of the first medium 11 is also preferably such that the amount of elastic wave displacement on the surface of the first medium 11 is substantially zero.

  The method for forming the second and third media 12 and 13 is not particularly limited. For example, the second and third media can be formed using a sputtering method, a vapor deposition method, a CVD method, a spin coating method, a bonding method, or the like. 12, 13 can be formed.

An IDT electrode 20 is formed at the boundary between the first medium 11 and the second medium 12. A dielectric layer 14 made of tantalum oxide such as Ta ₂ O ₅ is formed between the IDT electrode 20 and the first medium 11. By forming the dielectric layer 14, surge resistance can be improved. However, in the present invention, the dielectric layer 14 is not essential, and the IDT electrode 20 may be formed directly on the first medium 11.

  The IDT electrode 20 has at least three electrode layers stacked. Specifically, the IDT electrode 20 includes a first electrode layer 21 formed on the first medium 11, and a second electrode layer 22 formed on the first electrode layer 21. And a third electrode layer 23 formed on the second electrode layer 22. Of these first to third electrode layers 21 to 23, the upper and lower first and third electrode layers 21 and 23 have a relatively high density. On the other hand, the density of the second electrode layer 22 positioned between the first and third electrode layers 21 and 23 is lower than that of the first and third electrode layers 21 and 23, respectively.

  The material for forming the first to third electrode layers 21 to 23 is not particularly limited as long as the density of the second electrode layer 22 is lower than the density of the first and third electrode layers 21 and 23. Each of the first and third electrode layers 21 and 23 is made of, for example, a metal selected from the group consisting of Au, Pt, W, Ta, Ag, and Cu, or Au, Pt, W, Ta, Ag, and Cu. You may consist of an alloy which has as a main component 1 or more types of metals chosen from the group. The second electrode layer 22 is a metal selected from the group consisting of Al, Ti, Mg, Cr, Fe, Ni, Ag and Cu, or a group consisting of Al, Ti, Mg, Cr, Fe, Ni, Ag and Cu. It may be made of an alloy containing as a main component one or more metals selected from Among these, for example, each of the first and third electrode layers 21 and 23 is made of Pt or an alloy containing Pt as a main component, and the second electrode layer 22 is made of Al or an alloy containing Al as a main component. Is preferred. In this case, it is possible to achieve both low resistance and high reliability of the IDT electrode 20.

  By the way, when manufacturing the boundary acoustic wave device 1, various characteristics such as frequency characteristics are adjusted by forming the third medium 13 after adjusting the thickness of the second medium 12. In this case, when the second medium 12 is formed, if the frequency characteristic deviates greatly from the intended frequency characteristic, it is necessary to largely change the thickness of the second medium 12.

  Here, since the thickness of the second medium 12 generally correlates with the sound speed of the higher order mode, the sound speed of the higher order mode also changes when the thickness of the second medium 12 changes. When the sound speed in the higher order mode changes, the ease of leakage to the first and third media 11 and 13 in the higher order mode also changes. For this reason, the magnitude of higher order mode spurs also changes. Specifically, when the sound speed of the higher-order mode is increased, the higher-order mode is liable to leak to the first and third media 11 and 13, and the magnitude of the higher-order mode spurious is reduced. On the other hand, when the sound speed of the higher-order mode becomes slower, the higher-order mode is confined to the second medium and is less likely to leak into the first and third media 11 and 13, and the magnitude of the higher-order mode spurious increases. Therefore, when the frequency characteristic or the like is adjusted by adjusting the thickness of the second medium 12, the size of the higher-order mode spurious becomes larger than a desired size, and the obtained boundary acoustic wave device may be defective. . As a result, the yield of the boundary acoustic wave device may decrease.

  In view of such a problem, as a result of earnest research, the present inventor can suppress the change in the sound speed of the higher-order mode accompanying the change in the thickness of the second medium 12 by devising the film configuration of the IDT electrode 20. I found. As a result, the boundary acoustic wave device of the present embodiment has been conceived in which the frequency characteristics and the like can be adjusted by adjusting the thickness of the second medium 12 without greatly changing the magnitude of the higher-order mode spurious. . Hereinafter, this will be described in more detail based on a specific example.

  First, the inventor examined the relationship between the thickness of the second medium 12 and the sound speed of the higher-order mode by changing h3 / (h1 + h3) variously in the boundary acoustic wave device having the following design parameters. The results are shown in FIGS.

(Design parameters in FIGS. 2 to 6)
First medium 11: 20 ° Y-cut X-propagation LiNbO ₃ substrate Second medium: SiO ₂ film Third medium: SiN film Third medium thickness: 1.0λ
Wavelength (λ) determined by the electrode finger pitch of the IDT electrode 20: 1.9 μm
Material of the first and third electrode layers 21 and 23: Pt
Material of the second electrode layer 22: Al
Sum of the thickness of the first electrode layer 21 and the thickness of the third electrode layer 23 (h1 + h3): 0.06λ
Thickness (h2) of second electrode layer 22: 0.14λ

  FIG. 2 is a graph showing the relationship between the thickness (H) of the second medium 12 and the sound speed in the higher-order mode when h3 / (h1 + h3) is 0.30.

  FIG. 3 is a graph showing the relationship between the thickness (H) of the second medium 12 and the sound speed of the higher-order mode when h3 / (h1 + h3) is 0.55.

  FIG. 4 is a graph showing the relationship between the thickness (H) of the second medium 12 and the sound speed in the higher-order mode when h3 / (h1 + h3) is 0.70.

  FIG. 5 is a graph showing the relationship between the thickness (H) of the second medium 12 and the sound speed of the higher-order mode when h3 / (h1 + h3) is 0.90.

  FIG. 6 is a graph showing the relationship between the thickness (H) of the second medium 12 and the sound speed of the higher-order mode when h3 / (h1 + h3) is 0.95.

  From the results shown in FIG. 2, it can be seen that when h3 / (h1 + h3) is as small as 0.30, the sound speed of the higher-order mode changes greatly with the change in the thickness (H) of the second medium 12. Specifically, it can be seen that as the thickness (H) of the second medium 12 increases, the sound speed of the higher-order mode rapidly decreases. From this result, for example, when the thickness (H) of the second medium 12 is reduced in order to adjust the frequency characteristics and the like, the magnitude of the higher-order mode spurious is reduced, but the second medium 12 It can be seen that when the thickness (H) is increased, the magnitude of the higher-order mode spurious increases. Therefore, when h3 / (h1 + h3) is as small as 0.30, the range of the thickness (H) of the second medium 12 that can be adjusted for adjusting the frequency characteristics is narrow, and in some cases, the frequency characteristics are preferable. In some cases, the adjustment cannot be made. In addition, when the thickness (H) of the second medium 12 is adjusted to be large for adjusting the frequency characteristics and the like, the magnitude of the higher-order mode spurious becomes too large and may be defective. Therefore, the yield of the boundary acoustic wave device is lowered.

  On the other hand, the results shown in FIGS. 3 to 6 show that when h3 / (h1 + h3) is large, the dependence of the sound speed of the higher mode on the thickness (H) of the second medium 12 is low. It can also be seen that as h3 / (h1 + h3) increases, the dependence of the higher-order mode sound velocity on the thickness (H) of the second medium 12 decreases. Specifically, when h3 / (h1 + h3) is 0.55 or less, the dependence of the sound speed of the higher mode on the thickness (H) of the second medium 12 is large. On the other hand, it can be seen that by making h3 / (h1 + h3) larger than 0.55, the dependence of the sound velocity of the higher mode on the thickness (H) of the second medium 12 can be made sufficiently small. That is, when h3 / (h1 + h3) is greater than 0.55, it is possible to effectively suppress the change in the sound speed of the higher-order mode with the change in the thickness (H) of the second medium 12. . Therefore, by setting h3 / (h1 + h3) to be greater than 0.55 and less than 0.95, it is effective that the magnitude of the higher-order mode spurious changes with the change in the thickness (H) of the second medium 12. Can be suppressed. For this reason, when 0.55 <h3 / (h1 + h3) <0.95, the thickness (H) of the second medium 12 can be freely changed to adjust the frequency characteristics and the like. Therefore, even when the thickness (H) of the second medium 12 is largely changed, it is possible to effectively suppress the size of the high-order mode spurious from becoming too large. Therefore, the boundary acoustic wave device 1 can be manufactured with a high yield.

  In addition, when h3 / (h1 + h3) is greater than 0.7, it is possible to more effectively suppress the change in the sound speed of the higher-order mode with the change in the thickness (H) of the second medium 12. Therefore, by setting 0.7 <h3 / (h1 + h3) <0.95, the boundary acoustic wave device 1 can be manufactured with a higher yield.

  Further, from the results shown in FIGS. 2 to 6, the thickness (H) of the second medium 12 is set to 0.3 <H / λ <0.7 while h3 / (h1 + h3) is in a predetermined range. Thus, it is possible to particularly effectively suppress the change in the sound speed of the higher mode with the change in the thickness (H) of the second medium 12. Therefore, the thickness (H) of the second medium 12 is preferably 0.3λ to 0.7λ.

  Next, when the thickness (h2) of the second electrode layer 22 is 0.07λ or 0.20λ, similarly, the thickness (H) of the second medium 12 is changed by variously changing h3 / (h1 + h3). And the sound speed of higher order modes were investigated. The results are shown in FIGS. Similarly, when the total thickness (h1 + h3) of the first and third electrode layers 21 and 23 is set to 0.04λ, h3 / (h1 + h3) is variously changed to change the thickness of the second medium 12 ( The relationship between H) and higher-order mode sound speed was investigated. The results are shown in FIGS.

  FIG. 7 shows the thickness (H) of the second medium 12 and the sound speed of the higher-order mode when the thickness (h2) of the second electrode layer 22 is 0.07λ and h3 / (h1 + h3) is 0.30. It is a graph showing the relationship.

  FIG. 8 shows the thickness (H) of the second medium 12 and the sound speed of the higher-order mode when the thickness (h2) of the second electrode layer 22 is 0.07λ and h3 / (h1 + h3) is 0.55. It is a graph showing the relationship.

  FIG. 9 shows the thickness (H) of the second medium 12 and the sound speed of the higher-order mode when the thickness (h2) of the second electrode layer 22 is 0.07λ and h3 / (h1 + h3) is 0.70. It is a graph showing the relationship.

  FIG. 10 shows the thickness (H) of the second medium 12 and the sound speed of the higher-order mode when the thickness (h2) of the second electrode layer 22 is 0.07λ and h3 / (h1 + h3) is 0.90. It is a graph showing the relationship.

  FIG. 11 shows the thickness (H) of the second medium 12 and the sound speed of the higher-order mode when the thickness (h2) of the second electrode layer 22 is 0.07λ and h3 / (h1 + h3) is 0.95. It is a graph showing the relationship.

  FIG. 12 shows the thickness (H) of the second medium 12 and the sound speed of the higher-order mode when the thickness (h2) of the second electrode layer 22 is 0.20λ and h3 / (h1 + h3) is 0.30. It is a graph showing the relationship.

  FIG. 13 shows the thickness (H) of the second medium 12 and the sound speed of the higher-order mode when the thickness (h2) of the second electrode layer 22 is 0.20λ and h3 / (h1 + h3) is 0.55. It is a graph showing the relationship.

  FIG. 14 shows the thickness (H) of the second medium 12 and the sound speed of the higher-order mode when the thickness (h2) of the second electrode layer 22 is 0.20λ and h3 / (h1 + h3) is 0.70. It is a graph showing the relationship.

  FIG. 15 shows the thickness (H) of the second medium 12 and the sound speed of the higher-order mode when the thickness (h2) of the second electrode layer 22 is 0.20λ and h3 / (h1 + h3) is 0.90. It is a graph showing the relationship.

  FIG. 16 shows the thickness (H) of the second medium 12 and the sound speed of the higher-order mode when the thickness (h2) of the second electrode layer 22 is 0.20λ and h3 / (h1 + h3) is 0.95. It is a graph showing the relationship.

  FIG. 17 shows that the total thickness (h1 + h3) of the first and third electrode layers 21 and 23 is 0.04λ, the thickness (h2) of the second electrode layer 22 is 0.14λ, and h3 / (h1 + h3). 6 is a graph showing the relationship between the thickness (H) of the second medium 12 and the sound speed of a higher-order mode when is 0.30.

  In FIG. 18, the total thickness (h1 + h3) of the first and third electrode layers 21 and 23 is 0.04λ, the thickness (h2) of the second electrode layer 22 is 0.14λ, and h3 / (h1 + h3). 6 is a graph showing the relationship between the thickness (H) of the second medium 12 and the sound speed of a higher-order mode when is 0.55.

  In FIG. 19, the total thickness (h1 + h3) of the first and third electrode layers 21 and 23 is 0.04λ, the thickness (h2) of the second electrode layer 22 is 0.14λ, and h3 / (h1 + h3). 6 is a graph showing the relationship between the thickness (H) of the second medium 12 and the sound speed of the higher-order mode when is 0.70.

  In FIG. 20, the total thickness (h1 + h3) of the first and third electrode layers 21 and 23 is 0.04λ, the thickness (h2) of the second electrode layer 22 is 0.14λ, and h3 / (h1 + h3). 6 is a graph showing the relationship between the thickness (H) of the second medium 12 and the sound speed of a higher-order mode when is 0.90.

  FIG. 21 shows that the total thickness (h1 + h3) of the first and third electrode layers 21, 23 is 0.04λ, the thickness (h2) of the second electrode layer 22 is 0.14λ, and h3 / (h1 + h3). 6 is a graph showing the relationship between the thickness (H) of the second medium 12 and the sound speed of a higher-order mode when is 0.95.

  The results shown in FIGS. 7 to 16 are referred to together with the results shown in FIGS. As a result, regardless of the thickness (h2) of the second electrode layer 22, as h3 / (h1 + h3) increases, the dependency of the sound velocity of the higher mode on the change in the thickness (H) of the second medium 12 decreases. I understand that. Further, by setting h3 / (h1 + h3) to 0.55 to 0.95, preferably 0.7 to 0.95, the sound speed of the higher-order mode can be increased regardless of the thickness (H) of the second medium 12. It can be stabilized. Therefore, it can be seen that, when the thickness (H) of the second medium 12 is adjusted, it is possible to effectively suppress the size of the higher-order mode spurs from becoming too large.

  Regardless of the thickness (h2) of the second electrode layer 22, the thickness (H) of the second medium 12 is set to 0.3 <H / λ <0 while h3 / (h1 + h3) is within a predetermined range. .7, it is possible to particularly effectively suppress the change in the sound speed of the higher-order mode accompanying the change in the thickness (H) of the second medium 12. Therefore, it can be seen that the thickness (H) of the second medium 12 is preferably 0.3λ to 0.7λ regardless of the thickness of the second electrode layer 22.

  Note that the thickness (h2) of the second electrode layer 22 is preferably in the range of 0.05λ to 0.25λ. If the thickness (h2) of the second electrode layer 22 is too small, the dependency of the magnitude of higher-order mode spurious on the thickness (H) of the second medium 12 may not be sufficiently reduced. In addition, the frequency temperature characteristic may be deteriorated. On the other hand, if the thickness (h2) of the second electrode layer 22 is too large, the electromechanical coupling coefficient becomes too small, or the thickness of the IDT electrode 20 becomes too thick, and the shape of the third medium 13 becomes poor. There is a case.

  Next, the materials of the first to third electrode layers 21 to 23 were variously changed, and the relationship between the thickness (H) of the second medium 12 and the sound speed of the higher-order mode was examined. The results are shown in FIGS. 22 to 46, the total thickness (h1 + h3) of the first and third electrode layers 21 and 23 is 0.06λ, and the thickness (h2) of the second electrode layer 22 is 0.14λ. It is.

22 to 26: first electrode layer 21: Au / second electrode layer: Al / third electrode layer: Au
27 to 31: first electrode layer 21: W / second electrode layer: Al / third electrode layer: W
32 to 36: first electrode layer 21: Ta / second electrode layer: Al / third electrode layer: Ta
37 to 41: first electrode layer 21: Cu / second electrode layer: Al / third electrode layer: Cu FIGS. 42 to 46: first electrode layer 21: Pt / second electrode layer : Cu / third electrode layer: Pt
H3 / (h1 + h3) in FIGS. 22, 27, 32, 37 and 42: 0.30
H3 / (h1 + h3) in FIGS. 23, 28, 33, 38 and 43: 0.55
H3 / (h1 + h3): 0.70 in FIGS. 24, 29, 34, 39 and 44
H3 / (h1 + h3) in FIG. 25, FIG. 30, FIG. 35, FIG. 40 and FIG.
H3 / (h1 + h3) in FIGS. 26, 31, 36, 41 and 46: 0.95

  The results shown in FIGS. 22 to 46 are referred to together with the results shown in FIGS. From these results, regardless of the material of the first to third electrode layers 21 and 23, the higher the h3 / (h1 + h3), the higher the mode speed depends on the change in the thickness (H) of the second medium 12. It turns out that property becomes low. Further, by setting h3 / (h1 + h3) to 0.55 to 0.95, preferably 0.7 to 0.95, a higher-order mode is achieved regardless of the material of the first to third electrode layers 21 and 23. The speed of sound can be stabilized. Therefore, it can be seen that, when the thickness (H) of the second medium 12 is adjusted, it is possible to effectively suppress the size of the higher-order mode spurs from becoming too large.

  Regardless of the material of the first to third electrode layers 21 and 23, the thickness (H) of the second medium 12 is set to 0.3 <H / λ while h3 / (h1 + h3) is within a predetermined range. By setting it to <0.7, it can suppress especially effectively that the sound speed of a higher mode changes with the thickness (H) of the 2nd medium 12 changing. Therefore, it can be seen that the thickness (H) of the second medium 12 is preferably 0.3λ to 0.7λ regardless of the material of the first to third electrode layers 21 and 23.

Next, the cut angle of the first medium 11 was examined. FIG. 47 is a graph showing impedance (Z) characteristics when a 37 ° Y-cut LiNbO ₃ substrate is used as the first medium. FIG. 48 is a graph showing phase characteristics when a 37 ° Y-cut LiNbO ₃ substrate is used as the first medium. FIG. 49 is a graph showing impedance (Z) characteristics when a 0 ° Y-cut LiNbO ₃ substrate is used as the first medium. FIG. 50 is a graph showing phase characteristics when a 0 ° Y-cut LiNbO ₃ substrate is used as the first medium.

From the results shown in FIGS. 47 to 50, it is understood that when the 0 ° to 37 ° rotated Y-cut LiNbO ₃ substrate is used as the first medium 11, spurious due to the higher order mode of the SH wave is likely to occur. . Therefore, it can be seen that the technique of the present embodiment is particularly effective for the boundary acoustic wave device using the SH type boundary acoustic wave using the 0 ° -37 ° rotated Y-cut LiNbO ₃ substrate as the first medium 11.

(Second Embodiment)
FIG. 51 is a schematic cross-sectional view of a boundary acoustic wave device according to the second embodiment. As shown in FIG. 51, in this embodiment, the IDT electrode 20 further includes a fourth electrode layer 24 formed on the first to third electrode layers 21 to 23. Thus, by further providing the fourth electrode layer 24, the resistance of the IDT electrode 20 can be further reduced. Therefore, the loss of the boundary acoustic wave device can be further reduced.

  The fourth electrode layer 24 is formed of a material having a low electrical resistance, more specifically, a material having an electrical resistance equal to or lower than that of the materials of the first to third electrode layers 21 to 23. preferable. For example, the fourth electrode layer 24 is preferably formed of Al or an alloy containing Al as a main component. By doing so, the resistance of the IDT electrode 20 can be further reduced, and therefore the loss of the boundary acoustic wave device can be further reduced.

Further, when the fourth electrode layer 24 is formed of Al, it is preferable that the second medium 12 is made of silicon oxide such as SiO ₂ . Since Al and silicon oxide are close to each other in elastic constant and density, even if the fourth electrode layer 24 is added, the sound velocity in the fundamental mode, the electromechanical coupling coefficient, the sound velocity in the higher mode, etc. The acoustic characteristics are difficult to change. For this reason, the resistance of the IDT electrode 20 can be effectively reduced without changing the acoustic characteristics.

(Third embodiment)
FIG. 52 is a schematic cross-sectional view of an IDT electrode in a boundary acoustic wave device according to a third embodiment. As shown in FIG. 52, between the first medium 11 and the first electrode layer 21, between the first to third electrode layers 21 to 23, and between the third electrode layer 23 and the second medium 12. Further, layers 25a to 25d for improving adhesion and suppressing diffusion may be further provided. Each of the layers 25a to 25d may be formed of, for example, a metal such as Ti, Ni, or Cr, or an alloy mainly composed of one or more metals selected from the group consisting of Ti, Ni, and Cr. it can.

(Fourth embodiment)
FIG. 53 is a schematic cross-sectional view of an IDT electrode in a boundary acoustic wave device according to a fourth embodiment.

  In the said 1st Embodiment, the case where each of the 1st-3rd electrode layers 21-23 was formed with the single electrode layer was demonstrated. However, the present invention is not limited to this configuration. For example, at least one of the first to third electrode layers 21 to 23 may be composed of a plurality of layers. In that case, another layer may be interposed between a plurality of layers constituting the electrode layer. That is, at least one of the first to third electrode layers 21 to 23 may be divided into a plurality of layers by other layers, for example. For example, in the example shown in FIG. 53, the second electrode layer 22 is divided into three layers by layers 22a and 22b made of Ti or Cu.

(Fifth embodiment)
FIG. 54 is a schematic cross-sectional view of a boundary acoustic wave device according to a fifth embodiment.

  In the first embodiment, the case where the surface of the second medium 12 is flat has been described. However, as shown in FIG. 54, the surface of the second medium 12 has a shape corresponding to the shape of the IDT electrode 20. It may be said. Similarly, the surface of the third medium 13 may be shaped according to the shape of the IDT electrode 20.

(Sixth embodiment)
In the sixth embodiment, the first medium is a LiNbO ₃ substrate, the second medium is a SiO ₂ film, the cut angle of LiNbO ₃ , the thickness of each metal film in the IDT electrode, and the SiO ₂ film in the first embodiment. It differs from the first embodiment in that the thickness of the _two films is in a specific range. In the present embodiment, spurious due to the response of the Stoneley wave can be effectively suppressed. This will be described based on a specific experimental example.

  The results are shown in FIGS. 55 to 135 are described in the following first group to third group.

The first group to the third group are LiNbO ₃ cut angles, Pt film thickness total (h1 + h3), and upper Pt film thickness / Pt film thickness total (h3 / () suitable for use in a specific filter, respectively. h1 + h3)), the thickness of the Al film (h2), and the central value of each parameter of the SiO ₂ film (H). The first group to the third group are groups having parameters around the center value. Details will be explained for each group.

In addition, the SV wave specific band in this application is used in the meaning of the specific band of the Stoneley wave which is a boundary wave mainly composed of SV waves. When the electromechanical coefficient of the Stoneley wave and K, is in the approximate fractional bandwidth = K ^2/2 relationship.

(First group)
55 to 81, the cut angle of LiNbO ₃ is 25 °, the total Pt film thickness is 2.42% (vs. wavelength ratio), the upper Pt film thickness / the total Pt film thickness is 0.50, and the Al film thickness is 9.2. % (versus wavelength ratio), and the center 44.5% the thickness of the SiO ₂ film (versus wavelength ratio) is a diagram showing the relationship between the parameters and SV wave ratio band.

More specifically, FIGS. 55 to 63 show the results when the thickness of the SiO ₂ film is 0.40λ. 55 to 57 show the results when the upper Pt film thickness / Pt film thickness is 0.45, FIGS. 58 to 60 are 0.50, and FIGS. 61 to 63 are 0.55. ing. 55 to 57, the film thickness of the Al film is 0.08λ, 0.10λ, or 0.12λ. Also in FIGS. 58 to 60, the film thickness of the Al film is 0.08λ, The thickness of the Al film is 0.08λ, 0.10λ, or 0.12λ in FIGS. 61 to 63.

55 to 63 further show the relationship between the cut angle of LiNbO ₃ and the SV wave ratio band when the total Pt film thickness is changed to 0.02λ, 0.025λ, or 0.03λ. Has been.

  In FIGS. 55 to 135, the film thickness represented by “Pt =” such as Pt = 0.02λ in the drawings represents the total Pt film thickness.

As is apparent from FIGS. 55 to 63, when the cut angle of LiNbO ₃ is around 25 °, the SV wave ratio band becomes very small and becomes a minimum value. It can be seen that the SV wave ratio band increases as the cut angle moves away from 25 °.

64 to 72 show the results when the thickness of the SiO ₂ film is 0.45λ. Here, FIGS. 64 to 66 show the results when the upper Pt film thickness / Pt film thickness is 0.45, FIGS. 67 to 69 are 0.50, and FIGS. 70 to 72 are 0.55. ing. In FIGS. 64 to 66, the film thickness of the Al film is 0.08λ, 0.10λ, or 0.12λ. In FIGS. 67 to 69, the film thickness of the Al film is 0.08λ, The thickness of the Al film is 0.08λ, 0.10λ, or 0.12λ in FIGS. 70 to 72 as well.

64 to 72 further show the relationship between the cut angle of LiNbO ₃ and the SV wave ratio band when the total Pt film thickness is changed.

As is apparent from FIGS. 64 to 72, when the cut angle of LiNbO ₃ is around 25 °, the SV wave ratio band becomes very small and becomes a minimum value. It can be seen that the SV wave ratio band increases as the cut angle moves away from 25 °.

73 to 81 show results when the thickness of the SiO ₂ film is 0.50λ. 73 to 75 show the results when the upper Pt film thickness / Pt film thickness is 0.45, FIGS. 76 to 78 are 0.50, and FIGS. 79 to 81 are 0.55. ing. 73 to 75, the film thickness of the Al film is 0.08λ, 0.10λ, or 0.12λ. Also in FIGS. 76 to 78, the film thickness of the Al film is 0.08λ, The thickness of the Al film is also 0.08λ, 0.10λ, or 0.12λ in FIGS. 79 to 81.

73 to 81 further show the relationship between the cut angle of LiNbO ₃ and the SV wave ratio band when the total Pt film thickness is changed.

As is apparent from FIGS. 73 to 81, when the cut angle of LiNbO ₃ is around 25 °, the SV wave ratio band becomes very small and becomes a minimum value. It can be seen that the SV wave ratio band increases as the cut angle moves away from 25 °.

  Therefore, the results shown in FIGS. 55 to 81 are summarized as follows. When 0.55 <h3 / (h1 + h3) <0.95, the range in which the SV wave ratio band is 0.03% or less, that is, spurious due to the Stoneley wave. It can be seen that the range in which can be suppressed is any combination of the following (a1) to (a27).

(A1) Pt film thickness is 0.0175λ to 0.0225λ, upper Pt film thickness / Pt film thickness is 0.525 to 0.55, Al film thickness is 0.07λ to 0.09λ, and SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 21.5 ° ~ 27 °
(A2) Pt film thickness is 0.0225λ to 0.0275λ, upper Pt film thickness / Pt film thickness is 0.525 to 0.55, Al film thickness is 0.07λ to 0.09λ, SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 23 ° ~ 30.5 °
(A3) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.525 to 0.55, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 23.5 ° -30 °
(A4) Pt film thickness is 0.0175λ to 0.0225λ, upper Pt film thickness / Pt film thickness is 0.525 to 0.55, Al film thickness is 0.09λ to 0.11λ, and SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 21.5 ° ~ 27.5 °
(A5) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.525 to 0.55, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 23 ° -30 °
(A6) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.525 to 0.55, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 23.5 ° ~ 29.5 °
(A7) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.525 to 0.55, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 21.5 ° ~ 27.5 °
(A8) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.525 to 0.55, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 23 ° -30 °
(A9) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.525 to 0.55, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 23.5 ° ~ 29 °
(A10) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.525 to 0.55, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 23 ° ~ 28.5 °
(A11) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.525 to 0.55, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 24 ° to 31 °
(A12) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.525 to 0.55, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 23.5 ° -30 °
(A13) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.525 to 0.55, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 23 ° ~ 29 °
(A14) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.525 to 0.55, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 23.5 ° ~ 31 °
(A15) Pt film thickness is 0.0275λ to 0.0325λ, upper Pt film thickness / Pt film thickness is 0.525 to 0.55, Al film thickness is 0.09λ to 0.11λ, and SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 23.5 ° ~ 29 °
(A16) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.525 to 0.55, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 23 ° ~ 29.5 °
(A17) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.525 to 0.55, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 23.5 ° ~ 30.5 °
(A18) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.525 to 0.55, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 23.5 ° ~ 28.5 °
(A19) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.525 to 0.55, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.475λ to When 0.525λ, the cut angle of LiNbO ₃ is 24 ° -30 °
(A20) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.525 to 0.55, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.475λ to When 0.525λ, the cut angle of LiNbO ₃ is 24 ° ~ 31.5 °
(A21) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.525 to 0.55, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.475λ to When 0.525λ, the cut angle of LiNbO ₃ is 23 ° -30 °
(A22) Pt film thickness is 0.0175λ to 0.0225λ, upper Pt film thickness / Pt film thickness is 0.525 to 0.55, Al film thickness is 0.09λ to 0.11λ, and SiO ₂ film thickness is 0.475λ to When 0.525λ, the cut angle of LiNbO ₃ is 24 ° ~ 30.5 °
(A23) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.525 to 0.55, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.475λ to At 0.525λ, the cut angle of LiNbO ₃ is 24 ° to 31 °
(A24) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.525 to 0.55, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.475λ to When 0.525λ, the cut angle of LiNbO ₃ is 23.5 ° to 29 °
(A25) Pt film thickness is 0.0175λ to 0.0225λ, upper Pt film thickness / Pt film thickness is 0.525 to 0.55, Al film thickness is 0.11λ to 0.13λ, and SiO ₂ film thickness is 0.475λ to At 0.525λ, the cut angle of LiNbO ₃ is 23.5 ° to 30.5 °
(A26) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.525 to 0.55, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.475λ to At 0.525λ, the cut angle of LiNbO ₃ is 23.5 ° to 30.5 °
(A27) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.525 to 0.55, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.475λ to When 0.525λ, the cut angle of LiNbO ₃ is 23 ° to 28 °

(Second group)
82 to 108, the cut angle of LiNbO ₃ is 25 °, the total Pt film thickness is 2.72% (ratio to wavelength), the upper Pt film thickness / the total Pt film thickness is 0.78, and the Al film thickness is 7.9. % (versus wavelength ratio), and the center 45.6% the thickness of the SiO ₂ film (versus wavelength ratio) is a diagram showing the relationship between the parameters and SV wave ratio band.

More specifically, FIGS. 82 to 90 show results when the thickness of the SiO ₂ film is 0.40λ. Here, FIGS. 82 to 84 show the results when the upper Pt film thickness / Pt film thickness is 0.75, FIGS. 85 to 87 are 0.80, and FIGS. 88 to 90 are 0.85. ing. 82 to 84, the film thickness of the Al film is 0.06λ, 0.08λ, or 0.10λ. In FIGS. 85 to 87, the film thickness of the Al film is 0.06λ, The thickness of the Al film is 0.06λ, 0.08λ, or 0.10λ in FIGS. 88 to 90.

82 to 90 further show the relationship between the cut angle of LiNbO ₃ and the SV wave ratio band when the total Pt film thickness is changed to 0.02λ, 0.025λ, or 0.03λ. Has been.

As is apparent from FIGS. 82 to 90, when the cut angle of LiNbO ₃ is around 25 °, the SV wave ratio band becomes very small and becomes a minimum value. It can be seen that the SV wave ratio band increases as the cut angle moves away from 25 °.

91 to 99 show the results when the thickness of the SiO ₂ film is 0.45λ. Here, FIGS. 91 to 93 show the results when the upper Pt film thickness / Pt film thickness is 0.75, FIGS. 94 to 96 are 0.80, and FIGS. 97 to 99 are 0.85. ing. In FIGS. 91 to 93, the thickness of the Al film is 0.06λ, 0.08λ, or 0.10λ. In FIGS. 94 to 96, the thickness of the Al film is 0.06λ, The thickness of the Al film is 0.06λ, 0.08λ, or 0.10λ in FIGS. 97 to 99.

91 to 99 further show the relationship between the cut angle of LiNbO ₃ and the SV wave ratio band when the total Pt film thickness is changed.

As is apparent from FIGS. 91 to 99, when the cut angle of LiNbO ₃ is around 25 °, the SV wave ratio band becomes very small and becomes a minimum value. It can be seen that the SV wave ratio band increases as the cut angle moves away from 25 °.

100 to 108 show results when the thickness of the SiO ₂ film is 0.50λ. Here, FIGS. 100 to 102 show the results when the upper Pt film thickness / Pt film thickness is 0.75, FIGS. 103 to 105 are 0.80, and FIGS. 106 to 108 are 0.85. ing. 100 to 102, the film thickness of the Al film is 0.06λ, 0.08λ, or 0.10λ. In FIGS. 103 to 105, the film thickness of the Al film is 0.06λ, The thickness of the Al film is 0.06λ, 0.08λ, or 0.10λ in FIGS. 106 to 108.

100 to 108 further show the relationship between the cut angle of LiNbO ₃ and the SV wave ratio band when the total Pt film thickness is changed.

As is apparent from FIGS. 100 to 108, when the cut angle of LiNbO ₃ is around 25 °, the SV wave ratio band becomes very small and becomes a minimum value. It can be seen that the SV wave ratio band increases as the cut angle moves away from 25 °.

  Therefore, when the results of FIGS. 82 to 108 are summarized, when 0.55 <h3 / (h1 + h3) <0.95, the range in which the SV wave ratio band is 0.03% or less, that is, spurious due to the Stoneley wave. It can be seen that the range in which can be suppressed is a combination of any of the following (c1) to (c81).

(C1) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.725 to 0.775, the Al film thickness is 0.05λ to 0.07λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 22 ° ~ 28.5 °
(C2) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.725 to 0.775, the Al film thickness is 0.05λ to 0.07λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 23.5 ° -30 °
(C3) Pt film thickness is 0.0275λ to 0.0325λ, upper Pt film thickness / Pt film thickness is 0.725 to 0.775, Al film thickness is 0.05λ to 0.07λ, SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 23.5 ° ~ 28 °
(C4) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.725 to 0.775, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 22.5 ° ~ 29 °
(C5) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.725 to 0.775, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 24 ° ~ 29.5 °
(C6) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.725 to 0.775, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 24.5 ° ~ 26.5 °
(C7) Pt film thickness is 0.0175λ to 0.0225λ, upper Pt film thickness / Pt film thickness is 0.725 to 0.775, Al film thickness is 0.09λ to 0.11λ, and SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 23 ° to 29 °
(C8) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.725 to 0.775, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 24.5 ° to 29 °
(C9) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.725 to 0.775, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 23.5 ° ~ 26.5 °
(C10) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.05λ to 0.07λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 22.5 ° ~ 28.5 °
(C11) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.05λ to 0.07λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 23.5 ° -30 °
(C12) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.05λ to 0.07λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 23.5 ° ~ 27 °
(C13) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 23 ° to 29 °
(C14) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 24 ° to 29 °
(C15) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 23.5 ° ~ 26 °
(C16) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 23 ° ~ 29.5 °
(C17) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 25 ° ~ 28.5 °
(C18) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 22 ° ~ 26.5 °
(C19) Pt film thickness is 0.0175λ to 0.0225λ, upper Pt film thickness / Pt film thickness is 0.825 to 0.875, Al film thickness is 0.05λ to 0.07λ, and SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 23 ° to 29 °
(C20) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.05λ to 0.07λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 24 ° ~ 29.5 °
(C21) Pt film thickness is 0.0275λ to 0.0325λ, upper Pt film thickness / Pt film thickness is 0.825 to 0.875, Al film thickness is 0.05λ to 0.07λ, and SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 24 ° ~ 26.5 °
(C22) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 23 ° ~ 29.5 °
(C23) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 24.5 ° ~ 28.5 °
(C24) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 22.5 ° ~ 26 °
(C25) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 23.5 ° ~ 29.5 °
(C26) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 24.5 ° ~ 27 °
(C27) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 21 ° ~ 27 °
(C28) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.725 to 0.775, the Al film thickness is 0.05λ to 0.07λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 23.5 ° -30 °
(C29) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.725 to 0.775, the Al film thickness is 0.05λ to 0.07λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 24 ° ~ 30.5 °
(C30) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.725 to 0.775, the Al film thickness is 0.05λ to 0.07λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 23.5 ° ~ 28 °
(C31) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.725 to 0.775, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 23.5 ° -30 °
(C32) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.725 to 0.775, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 24 ° ~ 29.5 °
(C33) Pt film thickness is 0.0275λ to 0.0325λ, upper Pt film thickness / Pt film thickness is 0.725 to 0.775, Al film thickness is 0.07λ to 0.09λ, and SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 24 ° ~ 25.5 °
(C34) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.725 to 0.775, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 23.5 ° -30 °
(C35) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.725 to 0.775, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 24 ° ~ 28.5 °
(C36) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.725 to 0.775, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 22 ° ~ 26 °
(C37) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.05λ to 0.07λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 23.5 ° -30 °
(C38) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.05λ to 0.07λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 23.5 ° -30 °
(C39) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.05λ to 0.07λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 23.5 ° ~ 27 °
(C40) Pt film thickness is 0.0175λ to 0.0225λ, upper Pt film thickness / Pt film thickness is 0.775 to 0.825, Al film thickness is 0.07λ to 0.09λ, and SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 23.5 ° -30 °
(C41) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 24 ° to 29 °
(C42) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 22.5 ° ~ 25.5 °
(C43) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 24 ° -30 °
(C44) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 25 ° ~ 27 °
(C45) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 20.5 ° ~ 26 °
(C46) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.05λ to 0.07λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 23.5 ° -30 °
(C47) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.05λ to 0.07λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 24 ° ~ 29.5 °
(C48) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.05λ to 0.07λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 24 ° ~ 25.5 °
(C49) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 23.5 ° -30 °
(C50) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 24.5 ° -28 °
(C51) Pt film thickness is 0.0275λ to 0.0325λ, upper Pt film thickness / Pt film thickness is 0.825 to 0.875, Al film thickness is 0.07λ to 0.09λ, and SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 21 ° ~ 25.5 °
(C52) Pt film thickness is 0.0175λ to 0.0225λ, upper Pt film thickness / Pt film thickness is 0.825 to 0.875, Al film thickness is 0.09λ to 0.11λ, and SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 24 ° -30 °
(C53) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 24 ° ~ 26.5 °
(C54) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.425λ to When 0.475λ, the cut angle of LiNbO ₃ is 19.5 ° ~ 25.5 °
(C55) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.725 to 0.775, the Al film thickness is 0.05λ to 0.07λ, and the SiO ₂ film thickness is 0.475λ to At 0.525λ, the cut angle of LiNbO ₃ is 24 ° to 31 °
(C56) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.725 to 0.775, the Al film thickness is 0.05λ to 0.07λ, and the SiO ₂ film thickness is 0.475λ to At 0.525λ, the cut angle of LiNbO ₃ is 24 ° to 31 °
(C57) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.725 to 0.775, the Al film thickness is 0.05λ to 0.07λ, and the SiO ₂ film thickness is 0.475λ to When 0.525λ, the cut angle of LiNbO ₃ is 23 ° ~ 27.5 °
(C58) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.725 to 0.775, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.475λ to When 0.525λ, the cut angle of LiNbO ₃ is 24 ° ~ 3 °
(C59) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.725 to 0.775, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.475λ to When 0.525λ, the cut angle of LiNbO ₃ is 24 ° ~ 29 °
(C60) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.725 to 0.775, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.475λ to When 0.525λ, the cut angle of LiNbO ₃ is 23 ° ~ 26.5 °
(C61) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.725 to 0.775, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.475λ to When 0.525λ, the cut angle of LiNbO ₃ is 24 ° ~ 30.5 °
(C62) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.725 to 0.775, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.475λ to When 0.525λ, the cut angle of LiNbO ₃ is 24 ° ~ 27.5 °
(C63) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.725 to 0.775, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.475λ to When 0.525λ, the cut angle of LiNbO ₃ is 20.5 ° -25 °
(C64) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.05λ to 0.07λ, and the SiO ₂ film thickness is 0.475λ to At 0.525λ, the cut angle of LiNbO ₃ is 24 ° to 31 °
(C65) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.05λ to 0.07λ, and the SiO ₂ film thickness is 0.475λ to When 0.525λ, the cut angle of LiNbO ₃ is 24 ° -30 °
(C66) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.05λ to 0.07λ, and the SiO ₂ film thickness is 0.475λ to When 0.525λ, the cut angle of LiNbO ₃ is 23 ° ~ 26.5 °
(C67) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.475λ to At 0.525λ, the cut angle of LiNbO ₃ is 24 ° to 31 °
(C68) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.475λ to When 0.525λ, the cut angle of LiNbO ₃ is 24 ° ~ 28.5 °
(C69) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.475λ to When 0.525λ, the cut angle of LiNbO ₃ is 21.5 ° -25 °
(C70) Pt film thickness is 0.0175λ to 0.0225λ, upper Pt film thickness / Pt film thickness is 0.775 to 0.825, Al film thickness is 0.09λ to 0.11λ, and SiO ₂ film thickness is 0.475λ to When 0.525λ, the cut angle of LiNbO ₃ is 24 ° -30 °
(C71) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.475λ to When 0.525λ, the cut angle of LiNbO ₃ is 22 ° ~ 26 °
(C72) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.475λ to When 0.525λ, the cut angle of LiNbO ₃ is 19 ° ~ 25 °
(C73) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.05λ to 0.07λ, and the SiO ₂ film thickness is 0.475λ to At 0.525λ, the cut angle of LiNbO ₃ is 24 ° to 31 °
(C74) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.05λ to 0.07λ, and the SiO ₂ film thickness is 0.475λ to When 0.525λ, the cut angle of LiNbO ₃ is 24 ° ~ 29.5 °
(C75) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.05λ to 0.07λ, and the SiO ₂ film thickness is 0.475λ to At 0.525λ, the cut angle of LiNbO ₃ is 23.5 ° to 26 °
(C76) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.475λ to When 0.525λ, the cut angle of LiNbO ₃ is 24 ° ~ 30.5 °
(C77) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.475λ to When 0.525λ, the cut angle of LiNbO ₃ is 24 ° ~ 27 °
(C78) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.475λ to When 0.525λ, the cut angle of LiNbO ₃ is 20 ° ~ 25 °
(C79) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.475λ to When 0.525λ, the cut angle of LiNbO ₃ is 24.5 ° -30 °
(C80) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.475λ to When 0.525λ, the cut angle of LiNbO ₃ is 23 ° ~ 26 °
(C81) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.475λ to At 0.525λ, the cut angle of LiNbO ₃ is 18 ° to 24.5 °

(Third group)
109 to 135 show a cut angle of LiNbO ₃ of 25 °, a total Pt film thickness of 2.53% (vs. wavelength ratio), an upper Pt film thickness / total Pt film thickness of 0.86, and an Al film thickness of 9.0. % (versus wavelength ratio), and the center 36.3% the thickness of the SiO ₂ film (versus wavelength ratio) is a diagram showing the relationship between the parameters and SV wave ratio band.

More specifically, FIGS. 109 to 117 show results when the thickness of the SiO ₂ film is 0.30λ. Here, FIGS. 109 to 111 show the results when the upper Pt film thickness / Pt film thickness is 0.80, FIGS. 112 to 114 are 0.85, and FIGS. 115 to 117 are 0.90. ing. 109 to 111, the thickness of the Al film is 0.08λ, 0.10λ, or 0.12λ. In FIGS. 112 to 114, the thickness of the Al film is 0.08λ, The thickness of the Al film is 0.08λ, 0.10λ, or 0.12λ in FIGS. 115 to 117 as well.

109 to 117 further show the relationship between the cut angle of LiNbO ₃ and the SV wave ratio band when the total Pt film thickness is changed to 0.02λ, 0.025λ, or 0.03λ. Has been.

As is apparent from FIGS. 109 to 117, when the cut angle of LiNbO ₃ is around 25 °, the SV wave ratio band becomes very small and becomes a minimum value. It can be seen that the SV wave ratio band increases as the cut angle moves away from 25 °.

118 to 126 show the results when the thickness of the SiO ₂ film is 0.35λ. 118 to 120 show the results when the upper Pt film thickness / Pt film thickness is 0.80, FIGS. 121 to 123 are 0.85, and FIGS. 124 to 126 are 0.90. ing. 118 to 120, the thickness of the Al film is 0.08λ, 0.10λ, or 0.12λ. Also in FIGS. 121 to 123, the thickness of the Al film is 0.08λ, The thickness of the Al film is also 0.08λ, 0.10λ, or 0.12λ in FIGS. 124 to 126.

118 to 126 further show the relationship between the cut angle of LiNbO ₃ and the SV wave ratio band when the total Pt film thickness is changed.

As is apparent from FIGS. 118 to 126, when the cut angle of LiNbO ₃ is around 25 °, the SV wave ratio band becomes very small and becomes a minimum value. It can be seen that the SV wave ratio band increases as the cut angle moves away from 25 °.

127 to 135 show the results when the thickness of the SiO ₂ film is 0.40λ. 127 to 129 show the results when the upper Pt film thickness / Pt film thickness is 0.80, FIGS. 130 to 132 are 0.85, and FIGS. 133 to 135 are 0.90. ing. 127 to 129, the film thickness of the Al film is 0.08λ, 0.10λ, or 0.12λ, and also in FIGS. 130 to 132, the film thickness of the Al film is 0.08λ, The thickness of the Al film is 0.08λ, 0.10λ, or 0.12λ in FIGS. 133 to 135 as well.

127 to 135 further show the relationship between the cut angle of LiNbO ₃ and the SV wave ratio band when the total Pt film thickness is changed.

As is apparent from FIGS. 127 to 135, when the cut angle of LiNbO ₃ is around 25 °, the SV wave ratio band becomes very small and becomes a minimum value. It can be seen that the SV wave ratio band increases as the cut angle moves away from 25 °.

  Therefore, the results of FIGS. 109 to 135 are summarized as follows. When 0.55 <h3 / (h1 + h3) <0.95, the range in which the SV wave ratio band is 0.03% or less, that is, spurious due to the Stoneley wave. It can be seen that the range in which can be suppressed is a combination of any of the following (d1) to (d81).

(D1) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 19.5 ° -25 °
(D2) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 23.5 ° ~ 29.5 °
(D3) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 25.5 ° ~ 28.5 °
(D4) Pt film thickness is 0.0175λ to 0.0225λ, upper Pt film thickness / Pt film thickness is 0.775 to 0.825, Al film thickness is 0.09λ to 0.11λ, and SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 19 ° ~ 25 °
(D5) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 23.5 ° ~ 29.5 °
(D6) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 25.5 ° -28 °
(D7) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 18.5 ° -24 °
(D8) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 23.5 ° ~ 29.5 °
(D9) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 27 ° to 29 °
(D10) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 20 ° to 26 °
(D11) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 24 ° ~ 29.5 °
(D12) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 25 ° ~ 27.5 °
(D13) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 20 ° to 26 °
(D14) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 24.5 ° -30 °
(D15) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 26 ° ~ 29.5 °
(D16) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 19.5 ° ~ 25.5 °
(D17) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 25 ° -30 °
(D18) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 26 ° ~ 31 °
(D19) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.875 to 0.925, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 20.5 ° ~ 21.5 °
(D20) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.875 to 0.925, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 25 ° -30 °
(D21) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.875 to 0.925, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 25.5 ° to 29 °
(D22) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.875 to 0.925, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 21 ° ~ 27 °
(D23) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.875 to 0.925, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 26 ° -30 °
(D24) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.875 to 0.925, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 25 ° ~ 30.5 °
(D25) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.875 to 0.925, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 21 ° ~ 26.5 °
(D26) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.875 to 0.925, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 26.5 ° -30 °
(D27) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.875 to 0.925, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.275λ to When 0.325λ, the cut angle of LiNbO ₃ is 25.5 ° to 32 °
(D28) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 21.5 ° -28 °
(D29) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 24 ° ~ 29.5 °
(D30) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 25.5 ° ~ 26.5 °
(D31) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 21.5 ° -28 °
(D32) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 24.5 ° ~ 29.5 °
(D33) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 24 ° to 28 °
(D34) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 22 ° ~ 28 °
(D35) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 25.5 ° ~ 29 °
(D36) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 23.5 ° ~ 28.5 °
(D37) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 22 ° ~ 28.5 °
(D38) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 24.5 ° ~ 29.5 °
(D39) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 24 ° ~ 27 °
(D40) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 22.5 ° ~ 28.5 °
(D41) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 25 ° ~ 29 °
(D42) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 23 ° ~ 28.5 °
(D43) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 23 ° to 29 °
(D44) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 25 ° to 28 °
(D45) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 23 ° ~ 29.5 °
(D46) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.875 to 0.925, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 22.5 ° ~ 29 °
(D47) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.875 to 0.925, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 25 ° ~ 29 °
(D48) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.875 to 0.925, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 23 ° to 28 °
(D49) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.875 to 0.925, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 23.5 ° ~ 29 °
(D50) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.875 to 0.925, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 25 ° to 28 °
(D51) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.875 to 0.925, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 22 ° ~ 28.5 °
(D52) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.875 to 0.925, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 24 ° ~ 29.5 °
(D53) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.875 to 0.925, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 26 ° -30 °
(D54) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.875 to 0.925, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.325λ to When 0.375λ, the cut angle of LiNbO ₃ is 22 ° -30 °
(D55) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 22.5 ° ~ 29 °
(D56) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 24 ° to 29 °
(D57) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 23.5 ° ~ 26 °
(D58) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 23 ° ~ 29.5 °
(D59) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 25 ° ~ 28.5 °
(D60) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 22 ° ~ 27 °
(D61) Pt film thickness is 0.0175λ to 0.0225λ, upper Pt film thickness / Pt film thickness is 0.775 to 0.825, Al film thickness is 0.11λ to 0.13λ, and SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 23.5 ° ~ 29.5 °
(D62) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 25 ° to 28 °
(D63) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.775 to 0.825, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 21 ° ~ 27.5 °
(D64) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 23 ° ~ 29.5 °
(D65) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 24.5 ° ~ 28.5 °
(D66) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 22.5 ° ~ 26.5 °
(D67) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 23.5 ° ~ 29.5 °
(D68) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 24.5 ° ~ 28.5 °
(D69) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 21 ° ~ 27 °
(D70) Pt film thickness is 0.0175λ to 0.0225λ, upper Pt film thickness / Pt film thickness is 0.825 to 0.875, Al film thickness is 0.11λ to 0.13λ, and SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 24 ° -30 °
(D71) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 24 ° to 28 °
(D72) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.825 to 0.875, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 20 ° ~ 27.5 °
(D73) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.875 to 0.925, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 23.5 ° ~ 29.5 °
(D74) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.875 to 0.925, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 25 ° to 28 °
(D75) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.875 to 0.925, the Al film thickness is 0.07λ to 0.09λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 21.5 ° ~ 26.5 °
(D76) The total Pt film thickness is 0.0175λ to 0.0225λ, the upper Pt film thickness / Pt film thickness is 0.875 to 0.925, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 24 ° ~ 29.5 °
(D77) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.875 to 0.925, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 24.5 ° -28 °
(D78) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.875 to 0.925, the Al film thickness is 0.09λ to 0.11λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 20 ° ~ 27 °
(D79) Pt film thickness is 0.0175λ to 0.0225λ, upper Pt film thickness / Pt film thickness is 0.875 to 0.925, Al film thickness is 0.11λ to 0.13λ, and SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 25 ° to 29.5 °
(D80) The total Pt film thickness is 0.0225λ to 0.0275λ, the upper Pt film thickness / Pt film thickness is 0.875 to 0.925, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 23.5 ° ~ 29 °
(D81) The total Pt film thickness is 0.0275λ to 0.0325λ, the upper Pt film thickness / Pt film thickness is 0.875 to 0.925, the Al film thickness is 0.11λ to 0.13λ, and the SiO ₂ film thickness is 0.375λ to When 0.425λ, the cut angle of LiNbO ₃ is 19 ° ~ 27.5 °

(Seventh embodiment)
The seventh embodiment is similar to the second embodiment in that the fourth electrode layer 24 is formed on the first to third electrode layers 21 to 23, and thus the sixth embodiment. And different.

FIG. 136 is a diagram showing a change in the frequency temperature coefficient TCF when the thickness of the Al film that is the fourth electrode layer 24 is changed in the seventh embodiment. SiO ₂ has a positive frequency temperature coefficient TCF. LiNbO ₃ has a negative frequency temperature coefficient. LiNbO ₃ frequency temperature coefficient TCF of the boundary acoustic wave device formed by laminating a SiO ₂ substrate indicates the negative value of the intermediate of SiO ₂ film and the LiNbO ₃ substrate. As is apparent from FIG. 136, it can be seen that the absolute value of the frequency temperature coefficient TCF tends to increase as the thickness of the Al film as the fourth electrode layer 24 increases. The absolute value of the frequency temperature coefficient TCF is increased by replacing a part of SiO ₂ or the like with Al. 136 shows that the Pt film thickness is 0.03λ, the ratio of the upper Pt film to the total Pt film thickness = 1, and the film thickness of the Al film = 0 on the LiNbO ₃ substrate with a cut angle of 24 ° and a Y cut. The results when .10λ, the thickness of the SiO ₂ film = 0.50λ, and the thickness of the SiN film = 1.7λ are shown.

  As shown in FIG. 136, it can be seen that the frequency temperature coefficient TCF slightly deteriorates as the thickness of the Al film as the fourth electrode layer 24 is increased. For example, when the film thickness of the Al film as the fourth electrode layer 24 is 0.1λ, the frequency temperature coefficient TCF is about 2 ppm / ° C. compared to the case where the Al film as the fourth electrode layer 24 is not formed. It turns out that it has deteriorated. However, in other words, if the thickness of the Al film as the fourth electrode layer 24 is 0.1λ or less, the deterioration of the frequency temperature coefficient TCF can be within 2 ppm / ° C. Therefore, it can be seen that other characteristics such as the electromechanical coupling coefficient can be enhanced and Stoneley wave spurious can be effectively suppressed without significantly degrading the frequency temperature coefficient TCF. Therefore, more preferably, the thickness of the Al film that is the fourth electrode layer 24 is set to 0.1λ or less.

In the sixth embodiment, a dielectric layer 14 made of tantalum oxide such as Ta ₂ O ₅ may be formed between the IDT electrode 20 and the first medium 11.

  The thickness of the dielectric layer 14 is desirably thick to some extent in order to improve surge resistance. However, if the thickness of the dielectric layer 14 is too thick, the electromechanical coupling coefficient may be reduced. Therefore, the thickness of the dielectric layer 14 is preferably about 0.03λ or less. In addition, a decrease in the electromechanical coupling coefficient is suppressed as the dielectric constant of the dielectric layer 14 is increased. Therefore, a material having a high dielectric constant is desirable for the dielectric layer 14.

  The material constituting the dielectric layer 14 for improving the surge resistance is not limited to tantalum oxide, and various dielectric materials having a dielectric constant of about 10 or more can be used. That is, preferably, the dielectric layer 14 is formed of one kind of dielectric material selected from the group consisting of tantalum oxide, titanium oxide, and aluminum oxide having such a dielectric constant. It is particularly preferable to use tantalum oxide because of its high dielectric constant and high insulation resistance.

  Even in the structure in which the Al film as the fourth electrode layer 24 is laminated on the top, a Ti film or NiCr film is laminated on the lower surface side of the Al film as the fourth electrode layer 24 to prevent metal diffusion. The adhesion between the metal films may be increased. Note that the thickness of these other metal films is preferably not so large as not to affect the electrical characteristics, and is preferably as thin as, for example, about 20 nm or less.

  Further, in the laminated metal film, the Al film may be divided into a plurality of Al films. For example, the Al film itself may have a structure in which a plurality of Al films are stacked.

  Further, the Al film and the Pt film may be formed of an alloy mainly composed of Al or Pt.

DESCRIPTION OF SYMBOLS 1 ... Elastic boundary wave apparatus 11 ... 1st medium 12 ... 2nd medium 13 ... 3rd medium 14 ... Dielectric layer 20 ... IDT electrode 21 ... 1st electrode layer 22 ... 2nd electrode layer 23 ... 1st 3 electrode layer 24 ... 4th electrode layer 22a, 22b, 25a-25d ... layer

Claims (15)

A first medium made of a piezoelectric body;
A second medium formed on the first medium and made of a dielectric;
A third medium formed on the second medium and made of a dielectric;
An IDT electrode formed at a boundary between the first medium and the second medium;
A boundary acoustic wave device in which the sound speed of the second medium is slower than the sound speed of the first and third media,
The IDT electrode includes a first electrode layer formed on the first medium, a second electrode layer formed on the first electrode layer, and the second electrode layer. A third electrode layer formed on the substrate,
The density of the second electrode layer is lower than the density of the first and third electrode layers,
A boundary acoustic wave device satisfying 0.55 <h3 / (h1 + h3) <0.95, where h1 is the thickness of the first electrode layer and h3 is the thickness of the third electrode layer.   The boundary acoustic wave device according to claim 1, wherein 0.70 <h 3 / (h 1 + h 3) <0.95 is satisfied.   The thickness of the second electrode layer is h2, and the boundary acoustic wave wavelength determined by the pitch of the IDT electrode is λ, and 0.05 <h2 / λ <0.25 is satisfied. A boundary acoustic wave device according to claim 1.   The condition of 0.3 <H / λ <0.7 is satisfied, where H is the thickness of the second medium, and λ is the wavelength of the boundary acoustic wave determined by the pitch of the IDT electrodes. The boundary acoustic wave apparatus as described in any one of Claims.   Each of the first and third electrode layers is selected from a metal selected from the group consisting of Au, Pt, W, Ta, Ag and Cu or from a group consisting of Au, Pt, W, Ta, Ag and Cu. The boundary acoustic wave device according to any one of claims 1 to 4, wherein the boundary acoustic wave device is made of an alloy mainly containing one or more metals.   The second electrode layer is a metal selected from the group consisting of Al, Ti, Mg, Cr, Fe, Ni, Ag and Cu, or a group consisting of Al, Ti, Mg, Cr, Fe, Ni, Ag and Cu. The boundary acoustic wave apparatus as described in any one of Claims 1-5 which consists of an alloy which has as a main component 1 or more types of metals chosen from these.   Each of the first and third electrode layers is made of Pt or an alloy containing Pt as a main component, and the second electrode layer is made of Al or an alloy containing Al as a main component. A boundary acoustic wave device according to claim 1.   The boundary acoustic wave device according to any one of claims 1 to 7, wherein the second medium is made of silicon oxide. The boundary acoustic wave device according to any one of claims 1 to 8, wherein the first medium is made of LiNbO ₃ . The boundary acoustic wave device according to any one of claims 1 to 9, wherein the first medium is made of a 0 ° to 37 ° rotated Y-cut LiNbO ₃ substrate and uses an SH type boundary acoustic wave.   The boundary acoustic wave device according to any one of claims 1 to 10, wherein the third medium is made of silicon, silicon nitride, silicon carbide, aluminum oxide, or aluminum nitride.   The boundary acoustic wave device according to any one of claims 1 to 11, wherein the third medium is made of silicon nitride.   The boundary acoustic wave device according to any one of claims 1 to 12, further comprising a dielectric layer formed between the first medium and the IDT electrode. The first medium comprises a LiNbO ₃ substrate;
Each of the first and third electrode layers is made of Pt, the second electrode layer is made of Al,
The second medium is made of a SiO ₂ film;
The elasticity according to claim 1, wherein the cut angles of (h1 + h3), h3 / (h1 + h3), h2, H, and the LiNbO ₃ substrate are any combination of the following first to third groups. Boundary wave device.
(First group)
(A1) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 21.5 ° ~ 27 °
(A2) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23 ° ~ 30.5 °
(A3) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° -30 °
(A4) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 21.5 ° ~ 27.5 °
(A5) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23 ° -30 °
(A6) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° ~ 29.5 °
(A7) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.11λ to 0.13λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 21.5 ° ~ 27.5 °
(A8) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.11λ to 0.13λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23 ° -30 °
(A9) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.11λ to 0.13λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° ~ 29 °
(A10) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.07λ to 0.09λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23 ° ~ 28.5 °
(A11) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.07λ to 0.09λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 24 ° ~ 31 °
(A12) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.07λ to 0.09λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° -30 °
(A13) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.09λ to 0.11λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23 ° ~ 29 °
(A14) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.09λ to 0.11λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° to 31 °
(A15) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.09λ to 0.11λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° ~ 29 °
(A16) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.11λ to 0.13λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23 ° ~ 29.5 °
(A17) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.11λ to 0.13λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° ~ 30.5 °
(A18) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.11λ to 0.13λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° ~ 28.5 °
(A19) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.07λ to 0.09λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 30 °
(A20) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.07λ to 0.09λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 31.5 °
(A21) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.07λ to 0.09λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 23 ° -30 °
(A22) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.09λ to 0.11λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 30.5 °
(A23) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.09λ to 0.11λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 31 °
(A24) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.09λ to 0.11λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 23.5 ° ~ 29 °
(A25) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.11λ to 0.13λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 23.5 ° ~ 30.5 °
(A26) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.11λ to 0.13λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 23.5 ° ~ 30.5 °
(A27) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.55 to 0.575, h2 is 0.11λ to 0.13λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 23 ° ~ 28 °
(Second group)
(C1) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.05λ to 0.07λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 22 ° ~ 28.5 °
(C2) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.05λ to 0.07λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° -30 °
(C3) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.05λ to 0.07λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° ~ 28 °
(C4) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 22.5 ° ~ 29 °
(C5) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24 ° ~ 29.5 °
(C6) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24.5 ° ~ 26.5 °
(C7) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23 ° ~ 29 °
(C8) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24.5 ° ~ 29 °
(C9) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° ~ 26.5 °
(C10) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.05λ to 0.07λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 22.5 ° ~ 28.5 °
(C11) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.05λ to 0.07λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° -30 °
(C12) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.05λ to 0.07λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° ~ 27 °
(C13) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23 ° ~ 29 °
(C14) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24 ° ~ 29 °
(C15) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° ~ 26 °
(C16) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23 ° ~ 29.5 °
(C17) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 25 ° ~ 28.5 °
(C18) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 22 ° ~ 26.5 °
(C19) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.05λ to 0.07λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23 ° ~ 29 °
(C20) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.05λ to 0.07λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24 ° ~ 29.5 °
(C21) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.05λ to 0.07λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24 ° ~ 26.5 °
(C22) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23 ° ~ 29.5 °
(C23) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24.5 ° ~ 28.5 °
(C24) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 22.5 ° ~ 26 °
(C25) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° ~ 29.5 °
(C26) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24.5 ° ~ 27 °
(C27) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 21 ° ~ 27 °
(C28) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.05λ to 0.07λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° -30 °
(C29) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.05λ to 0.07λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 24 ° ~ 30.5 °
(C30) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.05λ to 0.07λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° ~ 28 °
(C31) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.07λ to 0.09λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° -30 °
(C32) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.07λ to 0.09λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 24 ° ~ 29.5 °
(C33) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.07λ to 0.09λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 24 ° ~ 25.5 °
(C34) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.09λ to 0.11λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° -30 °
(C35) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.09λ to 0.11λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 24 ° ~ 28.5 °
(C36) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.09λ to 0.11λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 22 ° ~ 26 °
(C37) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.05λ to 0.07λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° -30 °
(C38) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.05λ to 0.07λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° -30 °
(C39) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.05λ to 0.07λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° ~ 27 °
(C40) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° -30 °
(C41) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 24 ° ~ 29 °
(C42) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 22.5 ° ~ 25.5 °
(C43) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 24 ° ~ 30 °
(C44) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 25 ° ~ 27 °
(C45) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 20.5 ° ~ 26 °
(C46) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.05λ to 0.07λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° -30 °
(C47) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.05λ to 0.07λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 24 ° ~ 29.5 °
(C48) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.05λ to 0.07λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 24 ° ~ 25.5 °
(C49) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 23.5 ° -30 °
(C50) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 24.5 ° ~ 28 °
(C51) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 21 ° ~ 25.5 °
(C52) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 24 ° ~ 30 °
(C53) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 24 ° ~ 26.5 °
(C54) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.425λ to 0.475λ, LiNbO ₃ Cut angle is 19.5 ° ~ 25.5 °
(C55) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.05λ to 0.07λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 31 °
(C56) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.05λ to 0.07λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 31 °
(C57) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.05λ to 0.07λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 23 ° ~ 27.5 °
(C58) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.07λ to 0.09λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 3 °
(C59) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.07λ to 0.09λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 29 °
(C60) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.07λ to 0.09λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 23 ° ~ 26.5 °
(C61) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.09λ to 0.11λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 30.5 °
(C62) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.09λ to 0.11λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 27.5 °
(C63) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.725 to 0.775, h2 is 0.09λ to 0.11λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 20.5 ° -25 °
(C64) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.05λ to 0.07λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 31 °
(C65) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.05λ to 0.07λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 30 °
(C66) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.05λ to 0.07λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 23 ° ~ 26.5 °
(C67) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 31 °
(C68) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 28.5 °
(C69) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 21.5 ° ~ 25 °
(C70) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 30 °
(C71) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 22 ° ~ 26 °
(C72) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 19 ° ~ 25 °
(C73) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.05λ to 0.07λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 31 °
(C74) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.05λ to 0.07λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 29.5 °
(C75) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.05λ to 0.07λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 23.5 ° ~ 26 °
(C76) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 30.5 °
(C77) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24 ° ~ 27 °
(C78) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 20 ° ~ 25 °
(C79) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 24.5 ° -30 °
(C80) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 23 ° ~ 26 °
(C81) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.475λ to 0.525λ, LiNbO ₃ Cut angle is 18 ° ~ 24.5 °
(Third group)
(D1) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 19.5 ° ~ 25 °
(D2) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 23.5 ° ~ 29.5 °
(D3) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 25.5 ° ~ 28.5 °
(D4) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 19 ° ~ 25 °
(D5) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 23.5 ° ~ 29.5 °
(D6) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 25.5 ° ~ 28 °
(D7) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.11λ to 0.13λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 18.5 ° ~ 24 °
(D8) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.11λ to 0.13λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 23.5 ° ~ 29.5 °
(D9) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.11λ to 0.13λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 27 ° ~ 29 °
(D10) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 20 ° ~ 26 °
(D11) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 24 ° ~ 29.5 °
(D12) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 25 ° ~ 27.5 °
(D13) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 20 ° ~ 26 °
(D14) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 24.5 ° -30 °
(D15) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 26 ° ~ 29.5 °
(D16) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.11λ to 0.13λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 19.5 ° ~ 25.5 °
(D17) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.11λ to 0.13λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 25 ° -30 °
(D18) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.11λ to 0.13λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 26 ° ~ 31 °
(D19) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.07λ to 0.09λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 20.5 ° ~ 21.5 °
(D20) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.07λ to 0.09λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 25 ° -30 °
(D21) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.07λ to 0.09λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 25.5 ° ~ 29 °
(D22) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.09λ to 0.11λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 21 ° ~ 27 °
(D23) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.09λ to 0.11λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 26 ° -30 °
(D24) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.09λ to 0.11λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 25 ° ~ 30.5 °
(D25) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.11λ to 0.13λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 21 ° ~ 26.5 °
(D26) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.11λ to 0.13λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 26.5 ° -30 °
(D27) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.11λ to 0.13λ, and H is 0.275λ to 0.325λ, LiNbO ₃ Cut angle is 25.5 ° ~ 32 °
(D28) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 21.5 ° ~ 28 °
(D29) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 24 ° ~ 29.5 °
(D30) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 25.5 ° ~ 26.5 °
(D31) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 21.5 ° ~ 28 °
(D32) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 24.5 ° ~ 29.5 °
(D33) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 24 ° ~ 28 °
(D34) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.11λ to 0.13λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 22 ° ~ 28 °
(D35) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.11λ to 0.13λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 25.5 ° ~ 29 °
(D36) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.11λ to 0.13λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 23.5 ° ~ 28.5 °
(D37) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 22 ° ~ 28.5 °
(D38) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 24.5 ° ~ 29.5 °
(D39) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 24 ° ~ 27 °
(D40) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 22.5 ° ~ 28.5 °
(D41) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 25 ° ~ 29 °
(D42) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 23 ° ~ 28.5 °
(D43) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.11λ to 0.13λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 23 ° ~ 29 °
(D44) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.11λ to 0.13λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 25 ° ~ 28 °
(D45) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.11λ to 0.13λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 23 ° ~ 29.5 °
(D46) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.07λ to 0.09λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 22.5 ° ~ 29 °
(D47) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.07λ to 0.09λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 25 ° ~ 29 °
(D48) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.07λ to 0.09λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 23 ° ~ 28 °
(D49) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.09λ to 0.11λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 23.5 ° ~ 29 °
(D50) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.09λ to 0.11λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 25 ° ~ 28 °
(D51) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.09λ to 0.11λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 22 ° ~ 28.5 °
(D52) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.11λ to 0.13λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 24 ° ~ 29.5 °
(D53) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.11λ to 0.13λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 26 ° -30 °
(D54) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.11λ to 0.13λ, and H is 0.325λ to 0.375λ, LiNbO ₃ Cut angle is 22 ° ~ 30 °
(D55) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 22.5 ° ~ 29 °
(D56) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24 ° ~ 29 °
(D57) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° ~ 26 °
(D58) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23 ° ~ 29.5 °
(D59) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 25 ° ~ 28.5 °
(D60) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 22 ° ~ 27 °
(D61) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.11λ to 0.13λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° ~ 29.5 °
(D62) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.11λ to 0.13λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 25 ° ~ 28 °
(D63) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.775 to 0.825, h2 is 0.11λ to 0.13λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 21 ° ~ 27.5 °
(D64) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23 ° ~ 29.5 °
(D65) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24.5 ° ~ 28.5 °
(D66) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 22.5 ° ~ 26.5 °
(D67) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° ~ 29.5 °
(D68) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24.5 ° ~ 28.5 °
(D69) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 21 ° ~ 27 °
(D70) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.11λ to 0.13λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24 ° ~ 30 °
(D71) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.11λ to 0.13λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24 ° ~ 28 °
(D72) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.825 to 0.875, h2 is 0.11λ to 0.13λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 20 ° ~ 27.5 °
(D73) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° ~ 29.5 °
(D74) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 25 ° ~ 28 °
(D75) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.07λ to 0.09λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 21.5 ° ~ 26.5 °
(D76) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24 ° ~ 29.5 °
(D77) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 24.5 ° ~ 28 °
(D78) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.09λ to 0.11λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 20 ° ~ 27 °
(D79) When h1 + h3 is 0.0175λ to 0.0225λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.11λ to 0.13λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 25 ° ~ 29.5 °
(D80) When h1 + h3 is 0.0225λ to 0.0275λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.11λ to 0.13λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 23.5 ° ~ 29 °
(D81) When h1 + h3 is 0.0275λ to 0.0325λ, h3 / (h1 + h3) is 0.875 to 0.925, h2 is 0.11λ to 0.13λ, and H is 0.375λ to 0.425λ, LiNbO ₃ Cut angle is 19 ° ~ 27.5 ° A method for manufacturing a boundary acoustic wave device according to any one of claims 1 to 14,
A method for manufacturing a boundary acoustic wave device, wherein the third medium is formed after adjusting the frequency characteristics by adjusting the thickness of the second medium.

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