Surface acoustic wave resonance device, forming method thereof and filter

Abstract

The invention discloses a surface acoustic wave resonance device and a forming method thereof, and a filter, and the device comprises a first interdigital electrode structure located on the surface of a piezoelectric layer, the first interdigital electrode structure comprises a plurality of first electrode strips and a plurality of second electrode strips, and a first interval is formed between the adjacent first electrode strip and second electrode strip in a first direction; the first reflecting grating and the second reflecting grating are located on the surface of the piezoelectric layer, the first reflecting grating, the first interdigital electrode structure and the second reflecting grating are arranged in the first direction, and the first reflecting grating and the second reflecting grating are located on the two sides of the first interdigital electrode structure respectively; the second interdigital electrode structure is connected with the first interdigital electrode structure in parallel, the second interdigital electrode structure comprises a plurality of third electrode strips and a plurality of fourth electrode strips, a second interval is formed between the adjacent third electrode strips and fourth electrode strips in the first direction, and the second interval is larger than the first interval, so that the electromechanical coupling coefficient Kt2 is reduced, and the electromechanical coupling coefficient Kt2 is reduced; and the effect of improving the out-of-band roll-off of the filter is further achieved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technologies, and particularly to a surface acoustic wave resonator device, a forming method thereof, and a filter. Background Art

[0002] The radio frequency (RF) front-end chip of a wireless communication device includes a power amplifier, an antenna switch, an RF filter, a multiplexer, a low-noise amplifier, etc. Among them, the RF filter includes a piezoelectric surface acoustic wave (SAW) filter, a piezoelectric bulk acoustic wave (BAW) filter, a micro-electro-mechanical system (MEMS) filter, an integrated passive devices (IPD) filter, etc.

[0003] The quality factor value (Q value) of the surface acoustic wave resonator device is relatively high. The surface acoustic wave filter, which is made of the surface acoustic wave resonator device and has low insertion loss and high out-of-band rejection, is the mainstream RF filter used in wireless communication devices such as mobile phones and base stations.

[0004] However, the performance of the existing surface acoustic wave resonator devices still needs to be improved. Summary of the Invention

[0005] The technical problem solved by the present invention is to provide a surface acoustic wave resonator device, a forming method thereof, and a filter to improve the performance of the surface acoustic wave resonator device.

[0006] To solve the above technical problems, an embodiment of the present invention provides a surface acoustic wave resonator device, including: a piezoelectric layer; a first interdigital electrode structure located on the surface of the piezoelectric layer, the first interdigital electrode structure including a plurality of first electrode bars and a plurality of second electrode bars, the plurality of first electrode bars and the plurality of second electrode bars being parallel to a second direction and arranged alternately and spaced apart along a first direction, the first direction being different from the second direction, and a first interval being provided in the first direction between adjacent first electrode bars and second electrode bars; a first reflection grating and a second reflection grating located on the surface of the piezoelectric layer, the first reflection grating, the first interdigital electrode structure, and the second reflection grating being arranged along the first direction, and the first reflection grating and the second reflection grating being respectively located on both sides of the first interdigital electrode structure; a second interdigital electrode structure connected in parallel with the first interdigital electrode structure, the second interdigital electrode structure including a plurality of third electrode bars and a plurality of fourth electrode bars, the plurality of third electrode bars and the plurality of fourth electrode bars being parallel to the second direction and arranged alternately and spaced apart along the first direction, a second interval being provided in the first direction between adjacent third electrode bars and fourth electrode bars, and the second interval being greater than the first interval.

[0007] Optionally, the first direction is perpendicular to the second direction.

[0008] Optionally, it further includes: a third interdigital electrode structure adjacent to the second interdigital electrode structure and connected in parallel with the second interdigital electrode structure, the third interdigital electrode structure including a plurality of fifth electrode bars and a plurality of sixth electrode bars, the plurality of fifth electrode bars and the plurality of sixth electrode bars being parallel to the second direction and arranged alternately and spaced apart along the first direction, a third interval being provided in the first direction between adjacent fifth electrode bars and sixth electrode bars, the third interval being greater than the first interval, and the third interval being unequal to the second interval.

[0009] Optionally, the second interdigital electrode structure is located on the surface of the piezoelectric layer and is respectively located on opposite sides of the first reflection grating in the first direction with respect to the first interdigital electrode structure.

[0010] Optionally, the first interdigital electrode structure further includes a first bus bar and a second bus bar arranged in parallel along the second direction, a plurality of first electrode bars being connected to the first bus bar, a plurality of second electrode bars being connected to the second bus bar, the second interdigital electrode structure further includes a third bus bar and a fourth bus bar arranged in parallel along the second direction, a plurality of third electrode bars being connected to the third bus bar, a plurality of fourth electrode bars being connected to the fourth bus bar, the first bus bar being connected to the third bus bar, and the second bus bar being connected to the fourth bus bar.

[0011] Optionally, it further includes: a first connection line and a second connection line located on both sides of the first reflection grating in the second direction, the first bus and the third bus are electrically connected through the first connection line, and the second bus and the fourth bus are electrically connected through the second connection line.

[0012] Optionally, it further includes: a fourth interdigital electrode structure connected in parallel with the first interdigital electrode structure, the fourth interdigital electrode structure includes a plurality of seventh electrode bars and a plurality of eighth electrode bars, the plurality of seventh electrode bars and the plurality of eighth electrode bars are both parallel to the second direction and are arranged in an alternating and spaced manner along the first direction, and there is a fourth interval between adjacent seventh electrode bars and eighth electrode bars in the first direction, and the fourth interval is greater than the first interval.

[0013] Optionally, it further includes: a fifth interdigital electrode structure adjacent to the fourth interdigital electrode structure and connected in parallel with the fourth interdigital electrode structure, the fifth interdigital electrode structure includes a plurality of ninth electrode bars and a plurality of tenth electrode bars, the plurality of ninth electrode bars and the plurality of tenth electrode bars are both parallel to the second direction and are arranged in an alternating and spaced manner along the first direction, there is a fifth interval between adjacent ninth electrode bars and tenth electrode bars in the first direction, the fifth interval is greater than the first interval, and the fifth interval is not equal to the fourth interval.

[0014] Optionally, the fourth interdigital electrode structure is located on the surface of the piezoelectric layer and is respectively located on opposite sides of the second reflection grating in the first direction from the first interdigital electrode structure.

[0015] Optionally, the first interdigital electrode structure further includes a first bus and a second bus arranged in parallel along the second direction, a plurality of the first electrode bars are connected to the first bus, a plurality of the second electrode bars are connected to the second bus, the fourth interdigital electrode structure further includes a fifth bus and a sixth bus arranged in parallel along the second direction, a plurality of the seventh electrode bars are connected to the fifth bus, a plurality of the eighth electrode bars are connected to the sixth bus, the first bus is connected to the fifth bus, and the second bus is connected to the sixth bus.

[0016] Optionally, it further includes: a third connection line and a fourth connection line located on both sides of the second reflection grating in the second direction, the first bus and the fifth bus are electrically connected through the third connection line, and the second bus and the sixth bus are electrically connected through the fourth connection line.

[0017] Correspondingly, an embodiment of the present invention further provides a filter, including the surface acoustic wave resonator device described in any one of the above.

[0018] Accordingly, an embodiment of the present invention further provides a method for forming a surface acoustic wave resonator device, including: providing a piezoelectric layer; forming a first interdigital electrode structure, a first reflector, a second reflector, and a second interdigital electrode structure parallel to the first interdigital electrode structure on the surface of the piezoelectric layer, wherein the first reflector, the first interdigital electrode structure, and the second reflector are arranged along a first direction, and the first reflector and the second reflector are respectively located on both sides of the first interdigital electrode structure; forming the first interdigital electrode structure includes: forming a plurality of first electrode bars and a plurality of second electrode bars, the plurality of first electrode bars and the plurality of second electrode bars are both parallel to a second direction and are arranged at staggered intervals along the first direction, the first direction and the second direction are different, and there is a first interval between adjacent first electrode bars and second electrode bars in the first direction; forming the second interdigital electrode structure includes: forming a plurality of third electrode bars and a plurality of fourth electrode bars, the plurality of third electrode bars and the plurality of fourth electrode bars are both parallel to the second direction and are arranged at staggered intervals along the first direction, there is a second interval between adjacent third electrode bars and fourth electrode bars in the first direction, and the second interval is greater than the first interval.

[0019] Optionally, the second interdigital electrode structure and the first interdigital electrode structure are respectively located on opposite sides of the first reflector in the first direction.

[0020] Optionally, the method for forming the first interdigital electrode structure, the first reflector, the second reflector, and the second interdigital electrode structure includes: forming an electrode material layer on the surface of the piezoelectric layer; forming a patterned mask layer on the surface of the electrode material layer; etching the electrode material layer using the mask layer as a mask.

[0021] Optionally, the method for forming the first interdigital electrode structure, the first reflector, the second reflector, and the second interdigital electrode structure includes: forming a photoresist layer on the surface of the piezoelectric layer, and the photoresist layer exposes a part of the surface of the piezoelectric layer; forming an electrode material layer on the surface of the photoresist layer and the exposed surface of the piezoelectric layer; removing the photoresist layer and the electrode material layer on the surface of the photoresist layer.

[0022] Optionally, it further includes: forming a third interdigital electrode structure adjacent to the second interdigital electrode structure and parallel to the second interdigital electrode structure, the third interdigital electrode structure includes a plurality of fifth electrode bars and a plurality of sixth electrode bars, the plurality of fifth electrode bars and the plurality of sixth electrode bars are both parallel to the second direction and are arranged at staggered intervals along the first direction, there is a third interval between adjacent fifth electrode bars and sixth electrode bars in the first direction, the third interval is greater than the first interval, and the third interval is not equal to the second interval.

[0023] Optionally, it further includes: forming a fourth interdigital electrode structure on the surface of the piezoelectric layer, the fourth interdigital electrode structure being connected in parallel with the first interdigital electrode structure. The fourth interdigital electrode structure includes a plurality of seventh electrode bars and a plurality of eighth electrode bars. The plurality of seventh electrode bars and the plurality of eighth electrode bars are both parallel to the second direction and are arranged at staggered intervals along the first direction. There is a fourth interval between adjacent seventh electrode bars and eighth electrode bars in the first direction, and the fourth interval is greater than the first interval.

[0024] Optionally, it further includes: forming a fifth interdigital electrode structure adjacent to the fourth interdigital electrode structure and connected in parallel with the fourth interdigital electrode structure. The fifth interdigital electrode structure includes a plurality of ninth electrode bars and a plurality of tenth electrode bars. The plurality of ninth electrode bars and the plurality of tenth electrode bars are both parallel to the second direction and are arranged at staggered intervals along the first direction. There is a fifth interval between adjacent ninth electrode bars and tenth electrode bars in the first direction, the fifth interval is greater than the first interval, and the fifth interval is not equal to the fourth interval.

[0025] Optionally, the fourth interdigital electrode structure and the first interdigital electrode structure are respectively located on opposite sides of the second reflection grating in the first direction.

[0026] Compared with the prior art, the technical solution of the embodiment of the present invention has the following beneficial effects:

[0027] In the surface acoustic wave resonator device provided by the embodiment of the present invention, the first interdigital electrode structure, the first reflection grating, and the second reflection grating play the role of acoustic-electric conversion. By setting a second interdigital electrode structure connected in parallel with the first interdigital electrode structure outside the first reflection grating, since the first interdigital electrode structure has a first interval and the second interdigital electrode structure has a second interval, and the second interval is greater than the first interval, the resonance frequency of the second interdigital electrode structure is located outside the passband and plays the role of a capacitor, so that the surface acoustic wave resonator device reduces the anti-resonance frequency fp while the resonance frequency fs remains unchanged, thereby reducing the electromechanical coupling coefficient Kt 2 to decrease, and further achieving the effect of improving the roll-off outside the passband of the filter, making it more difficult for adjacent interference frequency bands to pass through, achieving the effect of enhancing the out-of-band suppression in the near end, or achieving the effect of reducing the passband bandwidth of the surface acoustic wave filter, which is generally beneficial to improving the performance of the surface acoustic wave filter; in addition, integrating the first interdigital electrode structure and the second interdigital electrode structure onto the surface of the piezoelectric layer is beneficial to improving the integration of the device and reducing the chip area.

[0028] Furthermore, the surface acoustic wave resonator device further includes: a fourth interdigital electrode structure connected in parallel with the first interdigital electrode structure, which is beneficial to further reducing the electromechanical coupling coefficient Kt 2, thereby improving the roll-off outside the filter passband, which is beneficial to improving the performance of the surface acoustic wave filter.

[0029] In the method for forming a surface acoustic wave resonator device provided by the embodiment of the present invention, the first interdigital electrode structure, the first reflection grating, and the second reflection grating play a role in acoustic-electric conversion. By arranging a second interdigital electrode structure in parallel with the first interdigital electrode structure outside the first reflection grating, since the first interdigital electrode structure has a first interval and the second interdigital electrode structure has a second interval, and the second interval is greater than the first interval, the manufacturing process of the second interdigital electrode structure is easier to implement, which is beneficial to improving the production process window. And the resonance frequency of the second interdigital electrode structure is outside the passband, and the second interdigital electrode structure plays the role of a capacitor, so that when the resonance frequency fs of the surface acoustic wave resonator device remains unchanged, the anti-resonance frequency fp is reduced, thereby making the electromechanical coupling coefficient Kt 2 decrease, thereby achieving the effect of improving the roll-off outside the filter passband, making it more difficult for adjacent interference frequency bands to pass through, achieving the effect of enhanced near-end out-of-band suppression, or achieving the effect of reducing the passband bandwidth of the surface acoustic wave filter, which is overall beneficial to improving the performance of the surface acoustic wave filter; in addition, integrating the first interdigital electrode structure and the second interdigital electrode structure onto the surface of the piezoelectric layer is beneficial to improving the device integration and reducing the chip area.

[0030] Further, the surface acoustic wave resonator device further includes: a fourth interdigital electrode structure in parallel with the first interdigital electrode structure, which is beneficial to further reducing the electromechanical coupling coefficient Kt 2 , thereby improving the roll-off outside the filter passband, which is beneficial to improving the performance of the surface acoustic wave filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic structural diagram of a surface acoustic wave resonator device;

[0032] Figure 2 is a schematic diagram of the admittance-frequency curve of a surface acoustic wave resonator device;

[0033] Figure 3 is a schematic diagram of the S21 parameter curve of a filter composed of a surface acoustic wave resonator device;

[0034] Figures 4 to 5 is a schematic structural diagram of a surface acoustic wave resonator device according to an embodiment of the present invention;

[0035] Figures 6 to 7 is a schematic structural diagram of a surface acoustic wave resonator device according to another embodiment of the present invention;

[0036] Figure 8 is a schematic structural diagram of a surface acoustic wave resonator device according to still another embodiment of the present invention;

[0037] Figure 9 It is a schematic structural diagram of a surface acoustic wave resonator according to another embodiment of the present invention. Detailed implementation manners

[0038] It should be noted that the "surface" and "upper" in the present invention are used to describe the relative positional relationship in space and do not limit whether there is direct contact.

[0039] As described in the background art, the performance of the surface acoustic wave resonator still needs to be improved. Now, a surface acoustic wave resonator will be described and analyzed in combination.

[0040] Figure 1 It is a schematic structural diagram of a surface acoustic wave resonator.

[0041] Please refer to Figure 1 , the surface acoustic wave resonator includes: a piezoelectric substrate; an interdigital electrode structure 101, a first reflection grating 102 and a second reflection grating 103 located on the piezoelectric substrate, and the first emission grating 102 and the second reflection grating 103 are respectively located on both sides of the interdigital electrode structure 101.

[0042] When the above surface acoustic wave resonator works, different potential voltages are applied to both ends of the interdigital electrode structure 101, and resonance and anti-resonance will occur at specific frequency points.

[0043] Figure 2 It is a schematic diagram of the admittance-frequency curve of a surface acoustic wave resonator.

[0044] Please refer to Figure 2 , through the admittance-frequency curve, the resonance frequency fs and the anti-resonance frequency fp of the surface acoustic wave resonator can be obtained, and then the electromechanical coupling coefficient Kt of the surface acoustic wave resonator can be obtained 2 , where the electromechanical coupling coefficient Kt 2 The relationship with the resonance frequency fs and the anti-resonance frequency fp is:

[0045] .

[0046] Figure 3 It is a schematic diagram of the S21 parameter curve of a filter composed of a surface acoustic wave resonator.

[0047] In the surface acoustic wave filter composed of the above surface acoustic wave resonator, please refer to Figure 3, for a band - pass filter (BPF), within the frequency range of the filter transmission band, the magnitude of the S21 parameter is relatively large and the input signal can pass through. While out - of - band, the magnitude of S21 is small and the input signal is suppressed. The relative bandwidth of the passband is defined as the bandwidth frequency range / the center frequency of the passband. The electromechanical coupling coefficient Kt of the resonant device 2 The most applicable numerical range is usually twice the relative bandwidth of the filter passband frequency band.

[0048] However, the electromechanical coupling coefficient Kt of the existing surface acoustic wave resonant devices 2 is usually too large, resulting in an overly wide passband, making it inapplicable to filters with a narrow passband bandwidth, and slowing down the steep drop from the passband to the stopband with high suppression indicators, seriously affecting the performance of the filter. Therefore, it is urgent to reduce the electromechanical coupling coefficient Kt of the surface acoustic wave resonant device 2 .

[0049] To solve the above problems, in an embodiment of the present invention, in a surface acoustic wave resonant device, its forming method, and a filter, the first interdigital electrode structure, the first reflection grating, and the second reflection grating play the role of acoustic - electric transducers. By arranging a second interdigital electrode structure in parallel with the first interdigital electrode structure outside the first reflection grating, since the first interdigital electrode structure has a first interval and the second interdigital electrode structure has a second interval, and the second interval is greater than the first interval, the manufacturing process of the second interdigital electrode structure is easier to implement, which is conducive to improving the production process window. And the resonant frequency of the second interdigital electrode structure is outside the passband, thus playing the role of a capacitor, so that when the resonant frequency fs of the surface acoustic wave resonant device remains unchanged, the anti - resonant frequency fp is reduced, and thus the electromechanical coupling coefficient Kt 2 is reduced, thereby achieving the effect of enhancing the roll - off outside the passband of the filter, making it more difficult for adjacent interference frequency bands to pass through, achieving the effect of enhancing the out - of - band suppression in the near - end, or achieving the effect of reducing the passband bandwidth of the surface acoustic wave filter, which is generally conducive to improving the performance of the surface acoustic wave filter; in addition, integrating the first interdigital electrode structure and the second interdigital electrode structure onto the surface of the piezoelectric layer is conducive to improving the integration of the device and reducing the chip area.

[0050] To make the above - mentioned objects, features, and beneficial effects of the present invention more obvious and understandable, the following will describe the specific embodiments of the present invention in detail with reference to the accompanying drawings.

[0051] Figures 4 to 5 is a schematic structural diagram of a surface acoustic wave resonant device according to an embodiment of the present invention.

[0052] In this embodiment, for the forming method of the surface acoustic wave resonant device, please refer toFigure 4 and Figure 5 , Figure 4 is Figure 5 a top - view structural schematic diagram of Figure 5 is Figure 4 a cross - sectional structural schematic diagram along the EE1 direction in , providing a piezoelectric layer 200.

[0053] In this embodiment, the piezoelectric layer 200 is a piezoelectric substrate.

[0054] The material of the piezoelectric layer 200 includes lithium tantalate, lithium niobate, aluminum nitride or zinc oxide.

[0055] In this embodiment, the material of the piezoelectric layer 202 is lithium tantalate.

[0056] In another embodiment, a substrate and a bonding layer are further provided, and the substrate and the piezoelectric layer are joined through the bonding layer, with the substrate and the piezoelectric layer located on both sides of the bonding layer.

[0057] Please continue to refer to Figure 4 and Figure 5 , a first interdigital electrode structure 201, a first reflection grating 211, a second reflection grating 212, and a second interdigital electrode structure 202 parallel to the first interdigital electrode structure 201 are formed on the surface of the piezoelectric layer 200. The first reflection grating 211, the first interdigital electrode structure 201, and the second reflection grating 212 are arranged along the first direction X, and the first reflection grating 211 and the second reflection grating 212 are respectively located on both sides of the first interdigital electrode structure 201; forming the first interdigital electrode structure 201 includes: forming a plurality of first electrode strips 2011 and a plurality of second electrode strips 2012. The plurality of first electrode strips 2011 and the plurality of second electrode strips 2012 are both parallel to the second direction Y and are arranged in an alternating and spaced manner along the first direction X. The first direction X and the second direction Y are different, and there is a first interval d1 between adjacent first electrode strips 2011 and second electrode strips 2012 in the first direction X; forming the second interdigital electrode structure 202 includes: forming a plurality of third electrode strips 2023 and a plurality of fourth electrode strips 2024. The plurality of third electrode strips 2023 and the plurality of fourth electrode strips 2024 are both parallel to the second direction Y and are arranged in an alternating and spaced manner along the first direction X. There is a second interval d2 between adjacent third electrode strips 2023 and fourth electrode strips 2024 in the first direction X, and the second interval d2 is greater than the first interval d1.

[0058] Here, the first interdigital electrode structure 201, the first reflection grating 211, and the second reflection grating 212 play the role of acoustic-electric transducers. By arranging a second interdigital electrode structure 202 parallel to the first interdigital electrode structure 201 outside the first reflection grating 211, since the first interdigital electrode structure 201 has a first interval d1, the second interdigital electrode structure 202 has a second interval d2, and the second interval d2 is greater than the first interval d1, the manufacturing process of the second interdigital electrode structure 202 is easier to implement, which is beneficial to improving the production process window. Moreover, the resonance frequency of the second interdigital electrode structure 202 is outside the passband, and the second interdigital electrode structure 202 functions as a capacitor, so that when the resonance frequency fs of the surface acoustic wave resonator device remains unchanged, the anti-resonance frequency fp is reduced, thereby making the electromechanical coupling coefficient Kt 2 decrease, and further achieving the effect of improving the roll-off outside the passband of the filter, making it more difficult for adjacent interference frequency bands to pass through, achieving the effect of enhancing the out-of-band suppression in the near end, or achieving the effect of reducing the passband bandwidth of the surface acoustic wave filter, which is generally beneficial to improving the performance of the surface acoustic wave filter; in addition, integrating the first interdigital electrode structure 201 and the second interdigital electrode structure 202 onto the surface of the piezoelectric layer 200 is beneficial to improving the integration of the device and reducing the chip area.

[0059] In this embodiment, the first direction X and the second direction Y are perpendicular to each other.

[0060] In another embodiment, the first direction and the second direction are different and not perpendicular to each other.

[0061] In this embodiment, the second interdigital electrode structure 202 and the first interdigital electrode structure 201 are respectively located on opposite sides of the first reflection grating 211 in the first direction X.

[0062] In this embodiment, the first interdigital electrode structure 201 further includes a first bus bar 201a and a second bus bar 201b arranged in parallel along the second direction Y. A plurality of the first electrode strips 2011 are connected to the first bus bar 201a, and a plurality of the second electrode strips 2012 are connected to the second bus bar 201b. The second interdigital electrode structure 202 further includes a third bus bar 202c and a fourth bus bar 202d arranged in parallel along the second direction Y. A plurality of the third electrode strips 2023 are connected to the third bus bar 202c, and a plurality of the fourth electrode strips 2024 are connected to the fourth bus bar 202d. The first bus bar 201a is connected to the third bus bar 202c, and the second bus bar 201b is connected to the fourth bus bar 202d.

[0063] In this embodiment, a first connection line 231 and a second connection line 232 are further formed on both sides of the first reflection grating 211 along the second direction Y. The first bus 201a and the third bus 202c are electrically connected through the first connection line 231, and the second bus 201b and the fourth bus 202d are electrically connected through the second connection line 232.

[0064] In this embodiment, the first reflection grating 211 includes a plurality of first reflection bars 2111 parallel to the second direction Y, and the plurality of first reflection bars 2111 are arranged along the first direction X.

[0065] In this embodiment, the first reflection grating 211 further includes a first end line 211a and a second end line 211b arranged along the second direction Y. One end of the plurality of first reflection bars 211 in the second direction is connected to the first end line 211a, and the other end is connected to the second end line 211b.

[0066] In another embodiment, the first reflection grating may not include the first end line and the second end line.

[0067] In this embodiment, the second reflection grating 212 includes a plurality of second reflection bars 2122 parallel to the second direction Y, and the plurality of second reflection bars 2122 are arranged along the first direction X.

[0068] In this embodiment, the second reflection grating 212 further includes a third end line 212c and a fourth end line 212d arranged along the second direction Y. One end of the plurality of second reflection bars 2122 in the second direction Y is connected to the third end line 212c, and the other end is connected to the fourth end line 212d.

[0069] In another embodiment, the second reflection grating may not include the third end line and the fourth end line.

[0070] In this embodiment, the forming method of the first interdigital electrode structure 201, the first reflection grating 211, the second reflection grating 212, and the second interdigital electrode structure 202 includes: forming an electrode material layer (not shown in the figure) on the surface of the piezoelectric layer 200; forming a patterned mask layer (not shown in the figure) on the surface of the electrode material layer; and etching the electrode material layer using the mask layer as a mask.

[0071] In another embodiment, the method for forming the first interdigital electrode structure, the first reflective grating, the second reflective grating, and the second interdigital electrode structure includes: forming a photoresist layer on the surface of the piezoelectric layer, with a part of the surface of the piezoelectric layer exposed by the photoresist layer; forming an electrode material layer on the surface of the photoresist layer and the exposed surface of the piezoelectric layer; and removing the photoresist layer and the electrode material layer on the surface of the photoresist layer.

[0072] In this embodiment, a second interdigital electrode structure 202 functioning as a capacitor is formed on one side of the first interdigital electrode structure 201.

[0073] In another embodiment, a third interdigital electrode structure adjacent to the second interdigital electrode structure is further formed. The third interdigital electrode structure is connected in parallel with the first interdigital electrode structure and also functions as a capacitor.

[0074] Specifically, the method further includes: forming a third interdigital electrode structure adjacent to the second interdigital electrode structure and connected in parallel with the second interdigital electrode structure. The third interdigital electrode structure includes a plurality of fifth electrode strips and a plurality of sixth electrode strips. The plurality of fifth electrode strips and the plurality of sixth electrode strips are both parallel to the second direction and are arranged at staggered intervals along the first direction. There is a third interval between adjacent fifth and sixth electrode strips in the first direction, and the third interval is greater than the first interval, and the third interval is not equal to the second interval.

[0075] In yet another embodiment, a fourth interdigital electrode structure functioning as a capacitor is also formed on the other side of the first interdigital electrode structure.

[0076] Specifically, the method further includes: forming a fourth interdigital electrode structure on the surface of the piezoelectric layer. The fourth interdigital electrode structure is connected in parallel with the first interdigital electrode structure. The fourth interdigital electrode structure includes a plurality of seventh electrode strips and a plurality of eighth electrode strips. The plurality of seventh electrode strips and the plurality of eighth electrode strips are both parallel to the second direction and are arranged at staggered intervals along the first direction. There is a fourth interval between adjacent seventh and eighth electrode strips in the first direction, and the fourth interval is greater than the first interval.

[0077] In still another embodiment, a fifth interdigital electrode structure adjacent to the fourth interdigital electrode structure is further formed. The fifth interdigital electrode structure is connected in parallel with the first interdigital electrode structure and also functions as a capacitor.

[0078] Specifically, the method further includes: forming a fifth interdigital electrode structure adjacent to the fourth interdigital electrode structure and in parallel connection with the fourth interdigital electrode structure. The fifth interdigital electrode structure includes a plurality of ninth electrode bars and a plurality of tenth electrode bars. The plurality of ninth electrode bars and the plurality of tenth electrode bars are both parallel to the second direction and are arranged in an alternating and spaced manner along the first direction. There is a fifth interval in the first direction between adjacent ninth electrode bars and tenth electrode bars. The fifth interval is greater than the first interval, and the fifth interval is not equal to the fourth interval.

[0079] Correspondingly, an embodiment of the present invention further provides a surface acoustic wave resonator device formed by the above method. Please continue to refer to Figure 4 and Figure 5 , which includes: a piezoelectric layer 200; a first interdigital electrode structure 201 located on the surface of the piezoelectric layer 200. The first interdigital electrode structure 201 includes a plurality of first electrode bars 2011 and a plurality of second electrode bars 2012. The plurality of first electrode bars 2011 and the plurality of second electrode bars 2012 are both parallel to the second direction Y and are arranged in an alternating and spaced manner along the first direction X. The first direction X and the second direction Y are different. There is a first interval d1 in the first direction between adjacent first electrode bars 2011 and second electrode bars 2012; a first reflection grating 211 and a second reflection grating 212 located on the surface of the piezoelectric layer 200. The first reflection grating 211, the first interdigital electrode structure 201, and the second reflection grating 212 are arranged along the first direction X, and the first reflection grating 211 and the second reflection grating 212 are respectively located on both sides of the first interdigital electrode structure 201; a second interdigital electrode structure 202 in parallel connection with the first interdigital electrode structure 201. The second interdigital electrode structure 202 includes a plurality of third electrode bars 2023 and a plurality of fourth electrode bars 2024. The plurality of third electrode bars 2023 and the plurality of fourth electrode bars 2024 are both parallel to the second direction Y and are arranged in an alternating and spaced manner along the first direction X. There is a second interval d2 in the first direction between adjacent third electrode bars 2023 and fourth electrode bars 2024. The second interval d2 is greater than the first interval d1.

[0080] Here, the first interdigital electrode structure 201, the first reflection grating 211, and the second reflection grating 212 function as acoustic-electric transducers. By disposing a second interdigital electrode structure 202 parallel to the first interdigital electrode structure 201 outside the first reflection grating 211, since the first interdigital electrode structure 201 has a first spacing d1, and the second interdigital electrode structure 202 has a second spacing d2, and the second spacing d2 is greater than the first spacing d1, the resonance frequency of the second interdigital electrode structure 202 is located outside the passband and functions as a capacitor, so that while the resonance frequency fs of the surface acoustic wave resonator device remains unchanged, the anti-resonance frequency fp is reduced, thereby making the electromechanical coupling coefficient Kt 2 decrease, further achieving the effect of enhancing the roll-off outside the passband of the filter, making it more difficult for adjacent interference frequency bands to pass through, achieving the effect of enhancing the out-of-band suppression in the near end, or achieving the effect of reducing the passband bandwidth of the surface acoustic wave filter, which is generally beneficial to improving the performance of the surface acoustic wave filter; in addition, integrating the first interdigital electrode structure 201 and the second interdigital electrode structure 202 onto the surface of the piezoelectric layer 200 is beneficial to improving the integration of the device and reducing the chip area.

[0081] In this embodiment, the first direction X and the second direction Y are perpendicular to each other.

[0082] In another embodiment, the first direction and the second direction are different and not perpendicular to each other.

[0083] In this embodiment, the second interdigital electrode structure 202 is located on the surface of the piezoelectric layer 200, and is respectively located on opposite sides of the first reflection grating 211 in the first direction X with the first interdigital electrode structure 201.

[0084] In this embodiment, the first interdigital electrode structure 201 further includes a first bus bar 201a and a second bus bar 201b arranged in parallel along the second direction Y. A plurality of the first electrode bars 2011 are connected to the first bus bar 201a, and a plurality of the second electrode bars 2012 are connected to the second bus bar 201b. The second interdigital electrode structure 202 further includes a third bus bar 202c and a fourth bus bar 202d arranged in parallel along the second direction Y. A plurality of the third electrode bars 2023 are connected to the third bus bar 202c, and a plurality of the fourth electrode bars 2024 are connected to the fourth bus bar 202d. The first bus bar 201a is connected to the third bus bar 202c, and the second bus bar 201b is connected to the fourth bus bar 202d.

[0085] In this embodiment, the surface acoustic wave resonator device further includes: a first connection line 231 and a second connection line 232 located on both sides of the first reflection grating 211 in the second direction Y. The first bus 201a is electrically connected to the third bus 202c through the first connection line 231, and the second bus 201b is electrically connected to the fourth bus 202d through the second connection line 232.

[0086] In this embodiment, the first reflection grating 211 includes a plurality of first reflection bars 2111 parallel to the second direction Y, and the plurality of first reflection bars 2111 are arranged along the first direction X.

[0087] In this embodiment, the first reflection grating 211 further includes: a first end line 211a and a second end line 211b arranged along the second direction Y. One end of the plurality of first reflection bars 2111 in the second direction is connected to the first end line 211a, and the other end is connected to the second end line 211b.

[0088] In another embodiment, the first reflection grating may not include the first end line and the second end line.

[0089] In this embodiment, the second reflection grating 212 includes a plurality of second reflection bars 2122 parallel to the second direction Y, and the plurality of second reflection bars 2122 are arranged along the first direction X.

[0090] In this embodiment, the second reflection grating 212 further includes: a third end line 212c and a fourth end line 212d arranged along the second direction Y. One end of the plurality of second reflection bars 2122 in the second direction Y is connected to the third end line 212c, and the other end is connected to the fourth end line 212d.

[0091] In another embodiment, the second reflection grating may not include the third end line and the fourth end line.

[0092] In this embodiment, one side of the first interdigital electrode structure 201 has a second interdigital electrode structure 202 that functions as a capacitor.

[0093] In another embodiment, there is also a third interdigital electrode structure adjacent to the second interdigital electrode structure. The third interdigital electrode structure is connected in parallel with the first interdigital electrode structure and also functions as a capacitor.

[0094] Specifically, the surface acoustic wave resonator device further includes: a third interdigital electrode structure adjacent to the second interdigital electrode structure and in parallel connection with the second interdigital electrode structure. The third interdigital electrode structure includes a plurality of fifth electrode strips and a plurality of sixth electrode strips. The plurality of fifth electrode strips and the plurality of sixth electrode strips are both parallel to the second direction and are arranged in an alternating and spaced manner along the first direction. There is a third interval between adjacent fifth electrode strips and sixth electrode strips in the first direction. The third interval is greater than the first interval, and the third interval is not equal to the second interval.

[0095] In another embodiment, on the other side of the first interdigital electrode structure, there is also a fourth interdigital electrode structure that functions as a capacitor.

[0096] Specifically, the surface acoustic wave resonator device further includes: a fourth interdigital electrode structure in parallel connection with the first interdigital electrode structure. The fourth interdigital electrode structure includes a plurality of seventh electrode strips and a plurality of eighth electrode strips. The plurality of seventh electrode strips and the plurality of eighth electrode strips are both parallel to the second direction and are arranged in an alternating and spaced manner along the first direction. There is a fourth interval between adjacent seventh electrode strips and eighth electrode strips in the first direction. The fourth interval is greater than the first interval.

[0097] In yet another embodiment, there is also a fifth interdigital electrode structure adjacent to the fourth interdigital electrode structure. The fifth interdigital electrode structure is in parallel connection with the first interdigital electrode structure and also functions as a capacitor.

[0098] Specifically, the surface acoustic wave resonator device further includes: a fifth interdigital electrode structure adjacent to the fourth interdigital electrode structure and in parallel connection with the fourth interdigital electrode structure. The fifth interdigital electrode structure includes a plurality of ninth electrode strips and a plurality of tenth electrode strips. The plurality of ninth electrode strips and the plurality of tenth electrode strips are both parallel to the second direction and are arranged in an alternating and spaced manner along the first direction. There is a fifth interval between adjacent ninth electrode strips and tenth electrode strips in the first direction. The fifth interval is greater than the first interval, and the fifth interval is not equal to the fourth interval.

[0099] Figures 6 to 7 It is a schematic structural diagram of a surface acoustic wave resonator device according to another embodiment of the present invention.

[0100] In this embodiment, for the formation method of the surface acoustic wave resonator device, please refer to Figure 6 and Figure 7 , Figure 6 is Figure 7 a top view structural diagram of Figure 7 is Figure 6Schematic cross-sectional structure diagram along the FF1 direction, providing a piezoelectric layer 300; a first interdigital electrode structure 301, a first reflecting grating 311, a second reflecting grating 312, and a second interdigital electrode structure 302 parallel to the first interdigital electrode structure 301 are formed on the surface of the piezoelectric layer 300. The first reflecting grating 311, the first interdigital electrode structure 301, and the second reflecting grating 312 are arranged along the first direction X, and the first reflecting grating 311 and the second reflecting grating 312 are respectively located on both sides of the first interdigital electrode structure 301; forming the first interdigital electrode structure 301 includes: forming a plurality of first electrode strips 3011 and a plurality of second electrode strips 3012. The plurality of first electrode strips 3011 and the plurality of second electrode strips 3012 are both parallel to the second direction Y and are arranged at staggered intervals along the first direction X. The first direction X and the second direction Y are different, and there is a first interval d1 between adjacent first electrode strips 3011 and second electrode strips 3012 in the first direction X; forming the second interdigital electrode structure 302 includes: forming a plurality of third electrode strips 3023 and a plurality of fourth electrode strips 3024. The plurality of third electrode strips 3023 and the plurality of fourth electrode strips 3024 are both parallel to the second direction Y and are arranged at staggered intervals along the first direction X. There is a second interval d2 between adjacent third electrode strips 3023 and fourth electrode strips 3024 in the first direction X, and the second interval d2 is greater than the first interval d1.

[0101] In this embodiment, the method further includes: forming a fourth interdigital electrode structure 304 parallel to the first interdigital electrode structure 301 on the surface of the piezoelectric layer 300. The fourth interdigital electrode structure 304 includes a plurality of seventh electrode strips 3047 and a plurality of eighth electrode strips 3048. The plurality of seventh electrode strips 3047 and the plurality of eighth electrode strips 3048 are both parallel to the second direction Y and are arranged at staggered intervals along the first direction X. There is a fourth interval d4 between adjacent seventh electrode strips 3047 and eighth electrode strips 3048 in the first direction X, and the fourth interval d4 is greater than the first interval d1.

[0102] Here, the fourth interdigital electrode structure 304 is beneficial to further reduce the electromechanical coupling coefficient Kt 2 , thereby improving the roll-off outside the passband of the filter and being beneficial to improving the performance of the surface acoustic wave filter.

[0103] In this embodiment, the fourth interdigital electrode structure 304 is located on the surface of the piezoelectric layer 300 and is respectively located on opposite sides of the second reflecting grating 312 in the first direction X with respect to the first interdigital electrode structure 301.

[0104] In this embodiment, the first direction X and the second direction Y are perpendicular to each other.

[0105] In this embodiment, the first interdigital electrode structure 301 further includes a first bus 301a and a second bus 301b arranged in parallel along the second direction Y. A plurality of the first electrode bars 3011 are connected to the first bus 301a, and a plurality of the second electrode bars 3012 are connected to the second bus 301b. The second interdigital electrode structure 302 further includes a third bus 302c and a fourth bus 302d arranged in parallel along the second direction Y. A plurality of the third electrode bars 3023 are connected to the third bus 302c, and a plurality of the fourth electrode bars 3024 are connected to the fourth bus 302d. The first bus 301a is connected to the third bus 302c, and the second bus 301b is connected to the fourth bus 302d.

[0106] In this embodiment, a first connection line 331 and a second connection line 332 are further formed on both sides of the first reflection grating 311 in the second direction Y. The first bus 301a and the third bus 302c are electrically connected through the first connection line 331, and the second bus 301b and the fourth bus 302d are electrically connected through the second connection line 332.

[0107] In this embodiment, the fourth interdigital electrode structure 304 further includes a fifth bus 304e and a sixth bus 304f arranged in parallel along the second direction Y. A plurality of the seventh electrode bars 3047 are connected to the fifth bus 304e, and a plurality of the eighth electrode bars 3048 are connected to the sixth bus 304f. The first bus 301a is connected to the fifth bus 304e, and the second bus 301b is connected to the sixth bus 304f.

[0108] In this embodiment, a third connection line 333 and a fourth connection line 334 are further formed on both sides of the second reflection grating 312 in the second direction Y. The first bus 301a and the fifth bus 304e are electrically connected through the third connection line 333, and the second bus 301b and the sixth bus 304f are electrically connected through the fourth connection line 334.

[0109] Correspondingly, an embodiment of the present invention further provides a surface acoustic wave resonator device formed by the above method. Please continue to refer to Figure 6 and Figure 7, including: a piezoelectric layer 300; a first interdigital electrode structure 301 located on the surface of the piezoelectric layer 300, the first interdigital electrode structure 301 includes a plurality of first electrode bars 3011 and a plurality of second electrode bars 3012, the plurality of first electrode bars 3011 and the plurality of second electrode bars 3012 are both parallel to the second direction Y and are arranged at staggered intervals along the first direction X, the first direction X and the second direction Y are different, and there is a first interval d1 in the first direction X between adjacent first electrode bars 3011 and second electrode bars 3012; a first reflection grating 311 and a second reflection grating 312 located on the surface of the piezoelectric layer 300, the first reflection grating 311, the first interdigital electrode structure 301 and the second reflection grating 312 are arranged along the first direction X, and the first reflection grating 311 and the second reflection grating 312 are respectively located on both sides of the first interdigital electrode structure 301; a second interdigital electrode structure 302 connected in parallel with the first interdigital electrode structure 301, the second interdigital electrode structure 302 includes a plurality of third electrode bars 3023 and a plurality of fourth electrode bars 3024, the plurality of third electrode bars 3023 and the plurality of fourth electrode bars 3024 are both parallel to the second direction Y and are arranged at staggered intervals along the first direction X, and there is a second interval d2 in the first direction X between adjacent third electrode bars 3023 and fourth electrode bars 3024, and the second interval d2 is greater than the first interval d1.

[0110] In this embodiment, the surface acoustic wave resonator device further includes: a fourth interdigital electrode structure 304 connected in parallel with the first interdigital electrode structure 301, the fourth interdigital electrode structure 304 includes a plurality of seventh electrode bars 3047 and a plurality of eighth electrode bars 3048, the plurality of seventh electrode bars 3047 and the plurality of eighth electrode bars 3048 are both parallel to the second direction Y and are arranged at staggered intervals along the first direction X, and there is a fourth interval d4 in the first direction X between adjacent seventh electrode bars 3047 and eighth electrode bars 3048, and the fourth interval d4 is greater than the first interval d1.

[0111] Herein, the fourth interdigital electrode structure 304 is beneficial to further reduce the electromechanical coupling coefficient Kt 2 , thereby improving the roll-off outside the filter passband and being beneficial to improving the performance of the surface acoustic wave filter.

[0112] In this embodiment, the fourth interdigital electrode structure 304 is located on the surface of the piezoelectric layer 300 and is respectively located on opposite sides of the second reflection grating 312 in the first direction X with respect to the first interdigital electrode structure 301.

[0113] In this embodiment, the first direction X and the second direction Y are perpendicular to each other.

[0114] In this embodiment, the second interdigital electrode structure 302 is located on the surface of the piezoelectric layer 300, and the first interdigital electrode structure 301 and the second interdigital electrode structure 302 are respectively located on opposite sides of the first reflection grating 311 in the first direction X.

[0115] In this embodiment, the first interdigital electrode structure 301 further includes a first bus line 301a and a second bus line 301b arranged in parallel along the second direction Y. A plurality of the first electrode bars 3011 are connected to the first bus line 301a, and a plurality of the second electrode bars 3012 are connected to the second bus line 301b. The second interdigital electrode structure 302 further includes a third bus line 302c and a fourth bus line 302d arranged in parallel along the second direction Y. A plurality of the third electrode bars 3023 are connected to the third bus line 302c, and a plurality of the fourth electrode bars 3024 are connected to the fourth bus line 302d. The first bus line 301a is connected to the third bus line 302c, and the second bus line 301b is connected to the fourth bus line 302d.

[0116] In this embodiment, the surface acoustic wave resonator device further includes: a first connection line 331 and a second connection line 332 located on both sides of the first reflection grating 311 in the second direction Y. The first bus line 301a and the third bus line 332 are electrically connected through the first connection line 331, and the second bus line 301b and the fourth bus line 302d are electrically connected through the second connection line 332.

[0117] In this embodiment, the fourth interdigital electrode structure 304 is located on the surface of the piezoelectric layer 300, and the fourth interdigital electrode structure 304 and the first interdigital electrode structure 3001 are respectively located on opposite sides of the second reflection grating 312 in the first direction X.

[0118] In this embodiment, the fourth interdigital electrode structure 304 further includes a fifth bus line 304e and a sixth bus line 304f arranged in parallel along the second direction Y. A plurality of the seventh electrode bars 3047 are connected to the fifth bus line 304e, and a plurality of the eighth electrode bars 3048 are connected to the sixth bus line 304f. The first bus line 301a is connected to the fifth bus line 304e, and the second bus line 301b is connected to the sixth bus line 304f.

[0119] In this embodiment, the surface acoustic wave resonator device further includes: a third connection line 333 and a fourth connection line 334 located on both sides of the second reflection grating 312 in the second direction Y. The first bus line 301a and the fifth bus line 304e are electrically connected through the third connection line 333, and the second bus line 301b and the sixth bus line 304f are electrically connected through the fourth connection line 334.

[0120] Figure 8 It is a schematic structural diagram of a surface acoustic wave resonator device according to another embodiment of the present invention.

[0121] In this embodiment, for the formation method of the surface acoustic wave resonator device, please refer to Figure 8 , including: providing a piezoelectric layer (not shown in the figure); forming a first interdigital electrode structure 401, a first reflection grating 411, a second reflection grating 412, and a second interdigital electrode structure 402 in parallel with the first interdigital electrode structure 401 on the surface of the piezoelectric layer. The first reflection grating 411, the first interdigital electrode structure 401, and the second reflection grating 412 are arranged along a first direction X, and the first reflection grating 411 and the second reflection grating 412 are respectively located on both sides of the first interdigital electrode structure 401; forming the first interdigital electrode structure 401 includes: forming a plurality of first electrode strips 4011 and a plurality of second electrode strips 4012. The plurality of first electrode strips 4011 and the plurality of second electrode strips 4012 are both parallel to a second direction Y and are arranged at staggered intervals along the first direction X. The first direction X and the second direction Y are different, and there is a first interval d1 between adjacent first electrode strips 4011 and second electrode strips 4012 in the first direction X; forming the second interdigital electrode structure 402 includes: forming a plurality of third electrode strips 4023 and a plurality of fourth electrode strips 4024. The plurality of third electrode strips 4023 and the plurality of fourth electrode strips 4024 are both parallel to the second direction Y and are arranged at staggered intervals along the first direction X. There is a second interval d2 between adjacent third electrode strips 4023 and fourth electrode strips 4024 in the first direction X, and the second interval d2 is greater than the first interval d1.

[0122] The main difference between this embodiment and the above embodiment is that: the first direction X and the second direction Y have a certain included angle, and the first direction X and the second direction Y are not perpendicular to each other.

[0123] Here, making the first direction X and the second direction Y not perpendicular to each other is beneficial to improving the flexibility of the arrangement of the first reflection grating 411, the first interdigital electrode structure 401, and the second reflection grating 412.

[0124] In this embodiment, the method further includes: forming a fourth interdigital electrode structure 404 in parallel with the first interdigital electrode structure 401 on the surface of the piezoelectric layer. The fourth interdigital electrode structure 404 includes a plurality of seventh electrode bars 4047 and a plurality of eighth electrode bars 4048. The plurality of seventh electrode bars 4047 and the plurality of eighth electrode bars 4048 are both parallel to the second direction Y and are arranged at staggered intervals along the first direction X. There is a fourth interval d4 in the first direction X between adjacent seventh electrode bars 4047 and eighth electrode bars 4048, and the fourth interval d4 is greater than the first interval d1.

[0125] In another embodiment, the fourth interdigital electrode structure may not be formed.

[0126] In this embodiment, the fourth interdigital electrode structure 404 is located on the surface of the piezoelectric layer, and the first interdigital electrode structure 401 and the fourth interdigital electrode structure 404 are respectively located on opposite sides of the second reflective grating 412 in the first direction X.

[0127] In this embodiment, the first interdigital electrode structure 401 further includes a first bus bar 401a and a second bus bar 401b arranged in parallel along the second direction Y. A plurality of first electrode bars 4011 are connected to the first bus bar 401a, and a plurality of second electrode bars 4012 are connected to the second bus bar 401b. The second interdigital electrode structure 402 further includes a third bus bar 402c and a fourth bus bar 402d arranged in parallel along the second direction Y. A plurality of third electrode bars 4023 are connected to the third bus bar 402c, and a plurality of fourth electrode bars 4024 are connected to the fourth bus bar 402d. The first bus bar 401a is connected to the third bus bar 402c, and the second bus bar 401b is connected to the fourth bus bar 402d.

[0128] In this embodiment, the method further includes: forming a first connection line 431 and a second connection line 432 on both sides of the first reflective grating 411 in the second direction Y. The first bus bar 401a and the third bus bar 402c are electrically connected through the first connection line 431, and the second bus bar 401b and the fourth bus bar 402d are electrically connected through the second connection line 432.

[0129] In this embodiment, the fourth interdigital electrode structure 404 further includes a fifth bus bar 404e and a sixth bus bar 404f arranged in parallel along the second direction Y. A plurality of seventh electrode bars 4047 are connected to the fifth bus bar 404e, and a plurality of eighth electrode bars 4048 are connected to the sixth bus bar 404f. The first bus bar 401a is connected to the fifth bus bar 404e, and the second bus bar 401b is connected to the sixth bus bar 404f.

[0130] In this embodiment, the method further includes: forming a third connection line 433 and a fourth connection line 434 on both sides of the second reflection grating 412 in the second direction Y, the first bus 401a and the fifth bus 404e are electrically connected through the third connection line 433, and the second bus 401b and the sixth bus 404f are electrically connected through the fourth connection line 434.

[0131] Correspondingly, an embodiment of the present invention further provides a surface acoustic wave resonator device formed by the above method. Please continue to refer to Figure 8 , including: a piezoelectric layer; a first interdigital electrode structure 401 located on the surface of the piezoelectric layer, the first interdigital electrode structure 401 includes a plurality of first electrode bars 4011 and a plurality of second electrode bars 4012, the plurality of first electrode bars 4011 and the plurality of second electrode bars 4012 are both parallel to the second direction Y and are arranged alternately at intervals along the first direction X, the first direction X and the second direction Y are different, and there is a first interval d1 between adjacent first electrode bars 4011 and second electrode bars 4012 in the first direction X; a first reflection grating 411 and a second reflection grating 412 located on the surface of the piezoelectric layer, the first reflection grating 411, the first interdigital electrode structure 401 and the second reflection grating 412 are arranged along the first direction X, and the first reflection grating 411 and the second reflection grating 412 are respectively located on both sides of the first interdigital electrode structure 401; a second interdigital electrode structure 402 connected in parallel with the first interdigital electrode structure 401, the second interdigital electrode structure 402 includes a plurality of third electrode bars 4023 and a plurality of fourth electrode bars 4024, the plurality of third electrode bars 4023 and the plurality of fourth electrode bars 4024 are both parallel to the second direction Y and are arranged alternately at intervals along the first direction X, and there is a second interval d2 between adjacent third electrode bars 4023 and fourth electrode bars 4024 in the first direction X, and the second interval d2 is greater than the first interval d1.

[0132] The main difference between this embodiment and the above embodiment is that: the first direction X and the second direction Y have a certain included angle, and the first direction X and the second direction Y are not perpendicular to each other.

[0133] Here, making the first direction X and the second direction Y not perpendicular to each other is beneficial to improving the flexibility of the arrangement of the first reflection grating 411, the first interdigital electrode structure 401 and the second reflection grating 412.

[0134] In this embodiment, the surface acoustic wave resonator device further includes: a fourth interdigital electrode structure 404 connected in parallel with the first interdigital electrode structure 401. The fourth interdigital electrode structure 404 includes a plurality of seventh electrode bars 4047 and a plurality of eighth electrode bars 4048. The plurality of seventh electrode bars 4047 and the plurality of eighth electrode bars 4048 are all parallel to the second direction Y and are arranged at staggered intervals along the first direction X. There is a fourth interval d4 between adjacent seventh electrode bars 4047 and eighth electrode bars 4048 in the first direction X, and the fourth interval d4 is greater than the first interval d1.

[0135] In another embodiment, the fourth interdigital electrode structure may not be included.

[0136] In this embodiment, the fourth interdigital electrode structure 404 is located on the surface of the piezoelectric layer, and the first interdigital electrode structure 401 and the fourth interdigital electrode structure 404 are respectively located on opposite sides of the second reflection grating 412 in the first direction X.

[0137] In this embodiment, the first interdigital electrode structure 401 further includes a first bus bar 401a and a second bus bar 401b arranged in parallel along the second direction Y. A plurality of first electrode bars 4011 are connected to the first bus bar 401a, and a plurality of second electrode bars 4012 are connected to the second bus bar 401b. The second interdigital electrode structure 402 further includes a third bus bar 402c and a fourth bus bar 402d arranged in parallel along the second direction Y. A plurality of third electrode bars 4023 are connected to the third bus bar 402c, and a plurality of fourth electrode bars 4024 are connected to the fourth bus bar 402d. The first bus bar 401a is connected to the third bus bar 402c, and the second bus bar 401b is connected to the fourth bus bar 402d.

[0138] In this embodiment, the surface acoustic wave resonator device further includes: a first connection line 431 and a second connection line 432 located on both sides of the first reflection grating 411 in the second direction Y. The first bus bar 401a and the third bus bar 402c are electrically connected through the first connection line 431, and the second bus bar 401b and the fourth bus bar 402d are electrically connected through the second connection line 432.

[0139] In this embodiment, the fourth interdigital electrode structure 404 further includes a fifth bus bar 404e and a sixth bus bar 404f arranged in parallel along the second direction Y. A plurality of seventh electrode bars 4047 are connected to the fifth bus bar 404e, and a plurality of eighth electrode bars 4048 are connected to the sixth bus bar 404f. The first bus bar 401a is connected to the fifth bus bar 404e, and the second bus bar 401b is connected to the sixth bus bar 404f.

[0140] In this embodiment, the surface acoustic wave resonance device further includes: a third connection line 433 and a fourth connection line 434 located on both sides of the second reflection grating 412 in the second direction Y. The first bus line 401a is electrically connected to the fifth bus line 404e through the third connection line 433, and the second bus line 401b is electrically connected to the sixth bus line 404f through the fourth connection line 434.

[0141] Figure 9 It is a schematic structural diagram of a surface acoustic wave resonance device according to another embodiment of the present invention.

[0142] In this embodiment, a method for forming another surface acoustic wave resonance device is further provided. For the structures and formation methods of the first interdigital electrode structure, the first reflection grating, the second reflection grating, and the second interdigital electrode structure, please continue to refer to Figure 6 and Figure 7 and the corresponding descriptions.

[0143] Please, on the basis of Figure 6 and Figure 7 continue to refer to Figure 9 , the method further includes: forming a third interdigital electrode structure 503 adjacent to the second interdigital electrode structure 302 and in parallel with the second interdigital electrode structure 302. The third interdigital electrode structure 503 includes a plurality of fifth electrode bars 5035 and a plurality of sixth electrode bars 5036. The plurality of fifth electrode bars 5035 and the plurality of sixth electrode bars 5036 are all parallel to the second direction Y and are arranged at staggered intervals along the first direction X. There is a third interval d3 between adjacent fifth electrode bars 5035 and sixth electrode bars 5036 in the first direction X. The third interval d3 is greater than the first interval d1, and the third interval d3 is not equal to the second interval d2.

[0144] Here, compared with the case where the third interval d3 is equal to the second interval d2, making the third interval d3 not equal to the second interval d2 can improve the freedom of capacitance adjustment, that is, increase the space for capacitance value adjustment.

[0145] It should be noted that Figure 9 the numbers of the third electrode bar 3023, the fourth electrode bar 3024, the fifth electrode bar 5035, and the sixth electrode bar 5036 shown in

[0146] In this embodiment, the method further includes: forming a fifth interdigital electrode structure 505 adjacent to and in parallel with the fourth interdigital electrode structure 304. The fifth interdigital electrode structure 505 includes a plurality of ninth electrode bars 5059 and a plurality of tenth electrode bars 5050. The plurality of ninth electrode bars 5059 and the plurality of tenth electrode bars 5050 are both parallel to the second direction Y and are arranged at staggered intervals along the first direction X. There is a fifth interval d5 between adjacent ninth electrode bar 5059 and tenth electrode bar 5050 in the first direction X. The fifth interval d5 is greater than the first interval d1, and the fifth interval d5 is not equal to the fourth interval d4.

[0147] It should be noted that Figure 9 the numbers of the seventh electrode bar 3047, the eighth electrode bar 3048, the ninth electrode bar 5059 and the tenth electrode bar 5050 shown in

[0148] are only for illustration and are not limited to the illustrated cases.

[0149] Correspondingly, an embodiment of the present invention further provides a surface acoustic wave resonator formed by the above method. For the structures of the first interdigital electrode structure, the first reflection grating, the second reflection grating and the second interdigital electrode structure, please continue to refer to Figure 6 and Figure 7 and the corresponding descriptions.

[0150] Please, on the basis of Figure 6 and Figure 7 continue to refer to Figure 9 , the surface acoustic wave resonator further includes: a third interdigital electrode structure 503 adjacent to and in parallel with the second interdigital electrode structure 302. The third interdigital electrode structure 503 includes a plurality of fifth electrode bars 5035 and a plurality of sixth electrode bars 5036. The plurality of fifth electrode bars 5035 and the plurality of sixth electrode bars 5036 are both parallel to the second direction Y and are arranged at staggered intervals along the first direction X. There is a third interval d3 between adjacent fifth electrode bar 5035 and sixth electrode bar 5036 in the first direction X. The third interval d3 is greater than the first interval d1, and the third interval d3 is not equal to the second interval d2.

[0151] In this embodiment, the surface acoustic wave resonator device further includes: a fifth interdigital electrode structure 505 adjacent to the fourth interdigital electrode structure 304 and in parallel connection with the fourth interdigital electrode structure 304. The fifth interdigital electrode structure 505 includes a plurality of ninth electrode bars 5059 and a plurality of tenth electrode bars 5050. The plurality of ninth electrode bars 5059 and the plurality of tenth electrode bars 5050 are all parallel to the second direction Y and are arranged alternately and spaced apart along the first direction X. There is a fifth interval d5 between an adjacent ninth electrode bar 5059 and tenth electrode bar 5050 in the first direction X. The fifth interval d5 is greater than the first interval d1, and the fifth interval d5 is not equal to the fourth interval d4.

[0152] In another embodiment, the fifth interdigital electrode structure may not be included.

[0153] Correspondingly, an embodiment of the present invention further provides a filter, including any one of the above surface acoustic wave resonator devices.

[0154] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be subject to the scope defined by the claims.

Claims

1. A surface acoustic wave resonator device, characterized in that, Comprising: A piezoelectric layer; A first interdigital electrode structure located on the surface of the piezoelectric layer, the first interdigital electrode structure comprising a plurality of first electrode bars and a plurality of second electrode bars, the plurality of first electrode bars and the plurality of second electrode bars being parallel to a second direction and arranged alternately and spaced apart along a first direction, the first direction and the second direction being different, and there being a first interval in the first direction between adjacent first electrode bars and second electrode bars; A first reflection grating and a second reflection grating located on the surface of the piezoelectric layer, the first reflection grating, the first interdigital electrode structure and the second reflection grating being arranged along the first direction, and the first reflection grating and the second reflection grating being located on both sides of the first interdigital electrode structure respectively; A second interdigital electrode structure connected in parallel with the first interdigital electrode structure, the second interdigital electrode structure comprising a plurality of third electrode bars and a plurality of fourth electrode bars, the plurality of third electrode bars and the plurality of fourth electrode bars being parallel to the second direction and arranged alternately and spaced apart along the first direction, there being a second interval in the first direction between adjacent third electrode bars and fourth electrode bars, the second interval being greater than the first interval.

2. The surface acoustic wave resonator device according to claim 1, wherein, The first direction and the second direction are perpendicular to each other.

3. The surface acoustic wave resonator device according to claim 1, wherein Further comprising: A third interdigital electrode structure adjacent to the second interdigital electrode structure and connected in parallel with the second interdigital electrode structure, the third interdigital electrode structure comprising a plurality of fifth electrode bars and a plurality of sixth electrode bars, the plurality of fifth electrode bars and the plurality of sixth electrode bars being parallel to the second direction and arranged alternately and spaced apart along the first direction, there being a third interval in the first direction between adjacent fifth electrode bars and sixth electrode bars, the third interval being greater than the first interval, and the third interval being unequal to the second interval.

4. The surface acoustic wave resonator device according to claim 1, wherein The second interdigital electrode structure is located on the surface of the piezoelectric layer and is located on opposite sides of the first reflection grating in the first direction with respect to the first interdigital electrode structure.

5. The surface acoustic wave resonator device according to claim 4, wherein The first interdigital electrode structure further comprises a first bus bar and a second bus bar arranged in parallel along the second direction, a plurality of the first electrode bars being connected to the first bus bar, a plurality of the second electrode bars being connected to the second bus bar, the second interdigital electrode structure further comprises a third bus bar and a fourth bus bar arranged in parallel along the second direction, a plurality of the third electrode bars being connected to the third bus bar, a plurality of the fourth electrode bars being connected to the fourth bus bar, the first bus bar being connected to the third bus bar, and the second bus bar being connected to the fourth bus bar.

6. The surface acoustic wave resonator device according to claim 5, wherein Further comprising: A first connection line and a second connection line located on both sides of the first reflection grating in the second direction, the first bus bar and the third bus bar being electrically connected through the first connection line, and the second bus bar and the fourth bus bar being electrically connected through the second connection line.

7. The surface acoustic wave resonator device according to claim 1, wherein, Further comprising: A fourth interdigital electrode structure connected in parallel with the first interdigital electrode structure. The fourth interdigital electrode structure includes a plurality of seventh electrode bars and a plurality of eighth electrode bars. The plurality of seventh electrode bars and the plurality of eighth electrode bars are both parallel to the second direction and are arranged alternately and spaced apart along the first direction. There is a fourth interval between adjacent seventh electrode bars and eighth electrode bars in the first direction, and the fourth interval is greater than the first interval.

8. The surface acoustic wave resonator device according to claim 7, characterized in that, Further comprising: A fifth interdigital electrode structure adjacent to the fourth interdigital electrode structure and connected in parallel with the fourth interdigital electrode structure. The fifth interdigital electrode structure includes a plurality of ninth electrode bars and a plurality of tenth electrode bars. The plurality of ninth electrode bars and the plurality of tenth electrode bars are both parallel to the second direction and are arranged alternately and spaced apart along the first direction. There is a fifth interval between adjacent ninth electrode bars and tenth electrode bars in the first direction, the fifth interval is greater than the first interval, and the fifth interval is not equal to the fourth interval.

9. The surface acoustic wave resonator device according to claim 7, wherein The fourth interdigital electrode structure is located on the surface of the piezoelectric layer and is respectively located on opposite sides of the second reflection grating in the first direction with the first interdigital electrode structure.

10. The surface acoustic wave resonator device according to claim 9, characterized in that, The first interdigital electrode structure further includes a first bus bar and a second bus bar arranged in parallel along the second direction. A plurality of the first electrode bars are connected to the first bus bar, and a plurality of the second electrode bars are connected to the second bus bar. The fourth interdigital electrode structure further includes a fifth bus bar and a sixth bus bar arranged in parallel along the second direction. A plurality of the seventh electrode bars are connected to the fifth bus bar, and a plurality of the eighth electrode bars are connected to the sixth bus bar. The first bus bar is connected to the fifth bus bar, and the second bus bar is connected to the sixth bus bar.

11. The surface acoustic wave resonator device according to claim 10, wherein, Further comprising: A third connection line and a fourth connection line located on both sides of the second reflection grating in the second direction. The first bus bar and the fifth bus bar are electrically connected through the third connection line, and the second bus bar and the sixth bus bar are electrically connected through the fourth connection line.

12. A filter, characterized in that, Comprising the surface acoustic wave resonator device according to any one of claims 1 to 11.

13. A method for forming a surface acoustic wave resonator device, characterized in that, Comprising: Providing a piezoelectric layer; Forming a first interdigital electrode structure, a first reflection grating, a second reflection grating, and a second interdigital electrode structure connected in parallel with the first interdigital electrode structure on the surface of the piezoelectric layer. The first reflection grating, the first interdigital electrode structure, and the second reflection grating are arranged along the first direction, and the first reflection grating and the second reflection grating are respectively located on both sides of the first interdigital electrode structure; Forming the first interdigital electrode structure includes: forming a plurality of first electrode bars and a plurality of second electrode bars. The plurality of first electrode bars and the plurality of second electrode bars are both parallel to the second direction and are arranged alternately and spaced apart along the first direction. The first direction and the second direction are different. There is a first interval between adjacent first electrode bars and second electrode bars in the first direction; Forming the second interdigital electrode structure includes: forming a plurality of third electrode bars and a plurality of fourth electrode bars, the plurality of third electrode bars and the plurality of fourth electrode bars are both parallel to the second direction and are arranged in an alternating and spaced manner along the first direction, and there is a second interval between adjacent third electrode bars and fourth electrode bars in the first direction, and the second interval is greater than the first interval.

14. The method for forming a surface acoustic wave resonator device according to claim 13, wherein The second interdigital electrode structure and the first interdigital electrode structure are respectively located on opposite sides of the first reflective grating in the first direction.

15. The method for forming a surface acoustic wave resonator device according to claim 13, characterized in that, The forming method of the first interdigital electrode structure, the first reflective grating, the second reflective grating, and the second interdigital electrode structure includes: forming an electrode material layer on the surface of the piezoelectric layer; forming a patterned mask layer on the surface of the electrode material layer; etching the electrode material layer using the mask layer as a mask.

16. The method for forming a surface acoustic wave resonator device according to claim 13, characterized in that, The forming method of the first interdigital electrode structure, the first reflective grating, the second reflective grating, and the second interdigital electrode structure includes: forming a photoresist layer on the surface of the piezoelectric layer, and the photoresist layer exposes a part of the surface of the piezoelectric layer; forming an electrode material layer on the surface of the photoresist layer and the exposed surface of the piezoelectric layer; removing the photoresist layer and the electrode material layer on the surface of the photoresist layer.

17. The method for forming a surface acoustic wave resonator device according to claim 13, characterized in that, Further included is: Forming a third interdigital electrode structure adjacent to the second interdigital electrode structure and in parallel with the second interdigital electrode structure, the third interdigital electrode structure includes a plurality of fifth electrode bars and a plurality of sixth electrode bars, the plurality of fifth electrode bars and the plurality of sixth electrode bars are both parallel to the second direction and are arranged in an alternating and spaced manner along the first direction, and there is a third interval between adjacent fifth electrode bars and sixth electrode bars in the first direction, the third interval is greater than the first interval, and the third interval is not equal to the second interval.

18. The method for forming a surface acoustic wave resonator device according to claim 13, wherein Further included is: Forming a fourth interdigital electrode structure on the surface of the piezoelectric layer, the fourth interdigital electrode structure is in parallel with the first interdigital electrode structure, the fourth interdigital electrode structure includes a plurality of seventh electrode bars and a plurality of eighth electrode bars, the plurality of seventh electrode bars and the plurality of eighth electrode bars are both parallel to the second direction and are arranged in an alternating and spaced manner along the first direction, and there is a fourth interval between adjacent seventh electrode bars and eighth electrode bars in the first direction, the fourth interval is greater than the first interval.

19. The method for forming a surface acoustic wave resonator device according to claim 18, characterized in that, Further included is: Forming a fifth interdigital electrode structure adjacent to the fourth interdigital electrode structure and in parallel with the fourth interdigital electrode structure, the fifth interdigital electrode structure includes a plurality of ninth electrode bars and a plurality of tenth electrode bars, the plurality of ninth electrode bars and the plurality of tenth electrode bars are both parallel to the second direction and are arranged in an alternating and spaced manner along the first direction, and there is a fifth interval between adjacent ninth electrode bars and tenth electrode bars in the first direction, the fifth interval is greater than the first interval, and the fifth interval is not equal to the fourth interval.

20. The method for forming a surface acoustic wave resonator device according to claim 18, wherein, The fourth interdigital electrode structure and the first interdigital electrode structure are respectively located on opposite sides of the second reflective grating in the first direction.

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