Surface acoustic wave resonance device and forming method thereof

Abstract

The invention discloses a surface acoustic wave resonance device and a forming method thereof. The structure comprises a middle layer, a first artificial finger layer and a second artificial finger layer which are located on a substrate, the first artificial finger layer is located on a first gap region, the second artificial finger layer is located on a second gap region, the first artificial finger layer comprises a plurality of first artificial finger parts, and the second artificial finger layer comprises a plurality of second artificial finger parts; a piezoelectric layer on the intermediate layer; the interdigital electrode structure is located on the surface of the piezoelectric layer and comprises a first bus, a second bus, a plurality of first electrode strips and a plurality of second electrode strips, the first electrode strips and the second electrode strips are arranged alternately, the first bus is located on the first bus area, the second bus is located on the second bus area, and the first electrode strips and the second electrode strips are arranged alternately. The plurality of first electrode strips are located on the first gap area and the overlapping area, and the plurality of second electrode strips are located on the overlapping area and the second gap area, so that sound waves can be prevented from leaking to the outside through the tail ends of the first electrode strips, and the quality factor of the surface acoustic wave resonance device can be improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a surface acoustic wave resonator device and a method for forming the same. Background Art

[0002] The radio frequency (RF) front-end chips for wireless communication devices include power amplifiers, antenna switches, RF filters, multiplexers, and low-noise amplifiers. RF filters include piezoelectric surface acoustic wave (SAW) filters, piezoelectric bulk acoustic wave (BAW) filters, micro-electro-mechanical system (MEMS) filters, and integrated passive device (IPD) filters.

[0003] Surface acoustic wave resonators (SAWs) have a high quality factor (Q value). RF filters made from these devices exhibit low insertion loss and high out-of-band rejection. These SAWs are the mainstream RF filters currently used in wireless communication devices such as mobile phones and base stations.

[0004] However, the performance of 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 and a forming method thereof, so as to improve the performance of a SAW filter.

[0006] In order to solve the above technical problems, the technical solution of the present invention provides a surface acoustic wave resonator device, including: a substrate, the surface of the substrate including a first bus area, a first gap area, an overlap area, a second gap area and a second bus area arranged along a first direction, the first gap area is located between the first bus area and the overlap area, and the second gap area is located between the second bus area and the overlap area; an intermediate layer, a first pseudo-finger layer and a second pseudo-finger layer located on the substrate, the first pseudo-finger layer and the second pseudo-finger layer are located in the intermediate layer, the first pseudo-finger layer is located on the first gap area, the second pseudo-finger layer is located on the second gap area, the first pseudo-finger layer includes a plurality of first pseudo-finger portions, the second pseudo-finger layer includes a plurality of second pseudo-finger portions, the plurality of first pseudo-finger portions and the plurality of second pseudo-finger portions are all parallel to the first direction and are arranged respectively along the second direction, the first direction and the second direction are different; a piezoelectric layer located on the intermediate layer, the substrate and the piezoelectric layer are located on both sides of the intermediate layer; an interdigitated electrode structure located on the surface of the piezoelectric layer, the interdigitated electrode structure including a first bus, A second bus, a plurality of first electrode strips and a plurality of second electrode strips, a plurality of the first electrode strips are connected to the first bus, a plurality of the second electrode strips are connected to the second bus, a plurality of the first electrode strips and a plurality of the second electrode strips are parallel to the first direction and arranged along the second direction, the first electrode strips and the second electrode strips are arranged alternately, the first bus is located on the first bus area, the second bus is located on the second bus area, a plurality of the first electrode strips are located on the first gap area and the overlapping area, a plurality of the second electrode strips are located on the overlapping area and the second gap area, and a plurality of the first electrode strips and a plurality of the second electrode strips on the overlapping area overlap along the second direction; the first false finger portion has a first projection on the substrate surface, the first electrode strip has a second projection on the substrate surface, the second false finger portion has a third projection on the substrate surface, the second electrode strip has a fourth projection on the substrate surface, the first projection and the fourth projection are arranged along the first direction, and the second projection and the third projection are arranged along the first direction.

[0007] Optionally, the first pseudo-finger layer further includes a plurality of third pseudo-finger portions, the third pseudo-finger portions and the first pseudo-finger portions are arranged alternately along the second direction, and one of the first electrode strips is located on one of the third pseudo-finger portions; the second pseudo-finger layer further includes a plurality of fourth pseudo-finger portions, the fourth pseudo-finger portions and the second pseudo-finger portions are arranged alternately along the second direction, and one of the second electrode strips is located on one of the fourth pseudo-finger portions.

[0008] Optionally, the first projection and the second projection are alternately arranged along the second direction; and the third projection and the fourth projection are alternately arranged along the second direction.

[0009] Optionally, along the first direction, there is a first spacing between the first projection and the fourth projection, and the ratio of the first spacing to the wavelength of the sound wave excited by the interdigitated electrode structure is in the range of 0.01 to 1; along the first direction, there is a second spacing between the second projection and the third projection, and the ratio of the second spacing to the wavelength of the sound wave excited by the interdigitated electrode structure is in the range of 0.01 to 1.

[0010] Optionally, the first pseudo-finger layer on the first gap region has a first length along the first direction, the first bus and the second electrode strip have a third spacing along the first direction, and the first length is smaller than the third spacing; the second pseudo-finger layer on the second gap region has a second length along the first direction, the second bus and the first electrode strip have a fourth spacing along the first direction, and the second length is smaller than the fourth spacing.

[0011] Optionally, the ratio of the first length to the wavelength of the acoustic wave excited by the interdigital electrode structure ranges from 0.01 to 2.5; the ratio of the second length to the wavelength of the acoustic wave excited by the interdigital electrode structure ranges from 0.01 to 2.5.

[0012] Optionally, the intermediate layer has a first surface and a second surface relative to each other, the first surface is adjacent to the substrate, and the second surface is adjacent to the piezoelectric layer; there is a fifth spacing between the first pseudo-finger layer and the first surface, and a sixth spacing between the first pseudo-finger layer and the second surface, and the sixth spacing is smaller than the fifth spacing; there is a seventh spacing between the second pseudo-finger layer and the first surface, and there is an eighth spacing between the second pseudo-finger layer and the second surface, and the eighth spacing is smaller than the seventh spacing.

[0013] Optionally, the material density of the first dummy finger layer and the second dummy finger layer is greater than the material density of the intermediate layer; the material of the first dummy finger layer and the second dummy finger layer includes a dielectric material or a metal material.

[0014] Optionally, the metal material includes a combination of one or more of aluminum, copper, molybdenum and platinum.

[0015] Optionally, the intermediate layer has a first thickness, and a ratio of the first thickness to the wavelength of the acoustic wave excited by the interdigitated electrode structure is in a range of 0.1 to 10.

[0016] Optionally, the piezoelectric layer has a second thickness, and a ratio of the second thickness to the wavelength of the acoustic wave excited by the interdigitated electrode structure is in a range of 0.1 to 20.

[0017] Correspondingly, the technical solution of the present invention also provides a surface acoustic wave resonance device method, including: providing a substrate, the surface of the substrate including a first bus area, a first gap area, an overlap area, a second gap area and a second bus area arranged along a first direction, the first gap area is located between the first bus area and the overlap area, and the second gap area is located between the second bus area and the overlap area; forming an intermediate layer, a first pseudo-finger layer and a second pseudo-finger layer, the first pseudo-finger layer and the second pseudo-finger layer are located in the intermediate layer, and the first pseudo-finger layer is located on the first gap area, the second pseudo-finger layer is located on the second gap area, the first pseudo-finger layer includes a plurality of first pseudo-finger portions, the second pseudo-finger layer includes a plurality of second pseudo-finger portions, the plurality of first pseudo-finger portions and the plurality of second pseudo-finger portions are all parallel to the first direction and are arranged respectively along the second direction, and the first direction and the second direction are different; providing a piezoelectric layer; bonding the substrate and the piezoelectric layer through the intermediate layer, the substrate and the piezoelectric layer are located on both sides of the intermediate layer; forming an interdigitated electrode structure on the surface of the piezoelectric layer, the interdigitated electrode structure includes a first interdigitated electrode structure. A bus, a second bus, a plurality of first electrode strips and a plurality of second electrode strips, a plurality of the first electrode strips are connected to the first bus, a plurality of the second electrode strips are connected to the second bus, a plurality of the first electrode strips and a plurality of the second electrode strips are parallel to the first direction and arranged along the second direction, the first electrode strips and the second electrode strips are arranged alternately, the first bus is located on the first bus area, the second bus is located on the second bus area, a plurality of the first electrode strips are located on the first gap area and the overlapping area, a plurality of the second electrode strips are located on the overlapping area and the second gap area, a plurality of the first electrode strips and a plurality of the second electrode strips on the overlapping area overlap along the second direction, the first false finger portion has a first projection on the substrate surface, the first electrode strip has a second projection on the substrate surface, the second false finger portion has a third projection on the substrate surface, the second electrode strip has a fourth projection on the substrate surface, the first projection and the fourth projection are arranged along the first direction, and the second projection and the third projection are arranged along the first direction.

[0018] Optionally, the method for forming the intermediate layer, the first pseudo-finger layer and the second pseudo-finger layer includes: forming a first bonding material layer on the surface of the substrate; forming a pseudo-finger material layer on the first bonding material layer; patterning the pseudo-finger material layer to form the first pseudo-finger layer and the second pseudo-finger layer; forming a second bonding material layer on the surface of the first bonding material layer, the first pseudo-finger layer and the second pseudo-finger layer, covering the first bonding material layer, the first pseudo-finger layer and the second pseudo-finger layer, with the first bonding material layer and the second bonding material layer as the intermediate layer; joining the substrate and the piezoelectric layer through the intermediate layer includes: bonding the intermediate layer and the piezoelectric layer.

[0019] Optionally, the method for forming the intermediate layer, the first pseudo-finger layer and the second pseudo-finger layer includes: forming a first bonding material layer on the surface of the substrate; forming a second bonding material layer on the surface of the piezoelectric layer; forming a pseudo-finger material layer on the second bonding material layer; patterning the pseudo-finger material layer to form the first pseudo-finger layer and the second pseudo-finger layer; forming a third bonding material layer on the surfaces of the second bonding material layer, the first pseudo-finger layer and the second pseudo-finger layer; bonding the substrate and the piezoelectric layer through the intermediate layer includes: bonding the first bonding material layer and the third bonding material layer to bond the substrate and the piezoelectric layer, with the first bonding material layer, the second bonding material layer and the third bonding material layer as the intermediate layer.

[0020] Optionally, the method for forming the intermediate layer, the first pseudo-finger layer and the second pseudo-finger layer includes: forming a first bonding material layer on the surface of the substrate; forming a pseudo-finger material layer on the first bonding material layer; patterning the pseudo-finger material layer to form the first pseudo-finger layer and the second pseudo-finger layer; forming a second bonding material layer on the surfaces of the first bonding material layer, the first pseudo-finger layer and the second pseudo-finger layer; forming a third bonding material layer on the surface of the piezoelectric layer; bonding the substrate and the piezoelectric layer through the intermediate layer includes: bonding the second bonding material layer and the third bonding material layer to bond the substrate and the piezoelectric layer, with the first bonding material layer, the second bonding material layer and the third bonding material layer as the intermediate layer.

[0021] Optionally, the method for forming the intermediate layer, the first pseudo-finger layer and the second pseudo-finger layer includes: forming a first bonding material layer on the surface of the substrate; forming a first pseudo-finger material layer on the first bonding material layer; patterning the first pseudo-finger material layer to form the first pseudo-finger layer; forming a second bonding material layer on the surface of the first bonding material layer and the first pseudo-finger layer; forming a second pseudo-finger material layer on the surface of the second bonding material layer; patterning the second pseudo-finger material layer to form the second pseudo-finger layer; forming a third bonding material layer on the surface of the second pseudo-finger layer and the surface of the second bonding material layer, forming the intermediate layer with the first bonding material layer, the second bonding material layer and the third bonding material layer; joining the substrate and the piezoelectric layer through the intermediate layer includes: bonding the intermediate layer and the piezoelectric layer.

[0022] Optionally, the method for forming the intermediate layer, the first pseudo-finger layer and the second pseudo-finger layer includes: forming a first bonding material layer on the surface of the substrate; forming a first pseudo-finger material layer on the first bonding material layer; patterning the first pseudo-finger material layer to form the first pseudo-finger layer; forming a second bonding material layer on the surface of the first bonding material layer and the first pseudo-finger layer; forming a second pseudo-finger material layer on the surface of the second bonding material layer; patterning the second pseudo-finger material layer to form the second pseudo-finger layer; forming a third bonding material layer on the surface of the second pseudo-finger layer and the surface of the second bonding material layer; forming a fourth bonding material layer on the surface of the piezoelectric layer; bonding the substrate and the piezoelectric layer through the intermediate layer includes: bonding the third bonding material layer and the fourth bonding material layer to bond the substrate and the piezoelectric layer, with the first bonding material layer, the second bonding material layer, the third bonding material layer and the fourth bonding material layer as the intermediate layer.

[0023] Optionally, the method for forming the intermediate layer, the first pseudo-finger layer and the second pseudo-finger layer includes: forming a first bonding material layer on the surface of the substrate; forming a second bonding material layer on the surface of the piezoelectric layer; forming a first pseudo-finger material layer on the second bonding material layer; patterning the first pseudo-finger material layer to form the first pseudo-finger layer; forming a third bonding material layer on the surfaces of the second bonding material layer and the first pseudo-finger layer; forming a second pseudo-finger material layer on the surface of the third bonding material layer; patterning the second pseudo-finger material layer to form the second pseudo-finger layer; forming a fourth bonding material layer on the surfaces of the second pseudo-finger layer and the third bonding material layer; bonding the substrate and the piezoelectric layer through the intermediate layer includes: bonding the first bonding material layer and the fourth bonding material layer to bond the substrate and the piezoelectric layer, with the first bonding material layer, the second bonding material layer, the third bonding material layer and the fourth bonding material layer as the intermediate layer.

[0024] Optionally, forming the first dummy finger layer also includes forming a plurality of third dummy finger portions, wherein the third dummy finger portions and the first dummy finger portions are alternately arranged along the second direction, and one of the first electrode strips is located on one of the third dummy finger portions; the method also includes: forming the third dummy finger portion at the same time as forming the first dummy finger portion.

[0025] Optionally, forming the second dummy finger layer also includes forming a plurality of fourth dummy finger portions, wherein the fourth dummy finger portions and the second dummy finger portions are alternately arranged along the second direction, and one of the second electrode strips is located on one of the fourth dummy finger portions; the method also includes: forming the fourth dummy finger portion at the same time as forming the second dummy finger portion.

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

[0027] In the surface acoustic wave resonance device provided by the technical solution of the present invention, the first dummy finger layer and the second dummy finger layer are located in the middle layer, the first dummy finger layer is located on the first gap area, and the second dummy finger layer is located on the second gap area. The first dummy finger portion has a first projection on the substrate surface, the first electrode strip has a second projection on the substrate surface, the second dummy finger portion has a third projection on the substrate surface, and the second electrode strip has a fourth projection on the substrate surface. The first projection and the fourth projection are arranged along the first direction, and the second projection and the third projection are arranged along the first direction. The first dummy finger layer reduces the speed of sound in the first gap area, which is beneficial to suppressing the leakage of sound waves through the end of the second electrode strip to the outside. The second dummy finger layer reduces the speed of sound in the second gap area, which is beneficial to suppressing the leakage of sound waves through the end of the first electrode strip to the outside, thereby helping to improve the quality factor of the surface acoustic wave resonance device.

[0028] Furthermore, the first pseudo-finger layer also includes a plurality of third pseudo-finger portions, and the second pseudo-finger layer also includes a plurality of fourth pseudo-finger portions, which can further suppress the leakage of sound waves through the end of the second electrode strip or the end of the second electrode strip to the outside, thereby further helping to improve the quality factor of the surface acoustic wave resonator device.

[0029] In the method for forming a surface acoustic wave resonant device provided by the technical solution of the present invention, the first dummy finger layer and the second dummy finger layer are located in the intermediate layer, the first dummy finger layer is located on the first gap area, and the second dummy finger layer is located on the second gap area. The first dummy finger portion has a first projection on the substrate surface, the first electrode strip has a second projection on the substrate surface, the second dummy finger portion has a third projection on the substrate surface, and the second electrode strip has a fourth projection on the substrate surface. The first projection and the fourth projection are arranged along the first direction, and the second projection and the third projection are arranged along the first direction. The first dummy finger layer reduces the speed of sound in the first gap area, which is beneficial to suppressing the leakage of sound waves through the end of the second electrode strip to the outside. The second dummy finger layer reduces the speed of sound in the second gap area, which is beneficial to suppressing the leakage of sound waves through the end of the first electrode strip to the outside, thereby helping to improve the quality factor of the surface acoustic wave resonant device.

[0030] Furthermore, the first pseudo-finger layer also includes a plurality of third pseudo-finger portions, and the second pseudo-finger layer also includes a plurality of fourth pseudo-finger portions, which can further suppress the leakage of sound waves through the end of the second electrode strip or the end of the second electrode strip to the outside, thereby further helping to improve the quality factor of the surface acoustic wave resonator device. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 and Figure 2 It is a structural diagram of a surface acoustic wave resonator device;

[0032] Figures 3 to 13 is a structural schematic diagram of a formation process of a surface acoustic wave resonator device according to one embodiment of the present invention;

[0033] Figures 14 to 19 It is a structural schematic diagram of the formation process of a surface acoustic wave resonator device in another embodiment of the present invention. DETAILED DESCRIPTION

[0034] It should be noted that the terms “surface” and “on” in this specification are used to describe relative positional relationships in space and are not limited to whether there is direct contact.

[0035] As mentioned in the background art, the performance of surface acoustic wave resonator devices needs to be improved.

[0036] Figure 1 and Figure 2 It is a structural diagram of a surface acoustic wave resonator device.

[0037] Please refer to Figure 1 and Figure 2 , Figure 1 The top view of the protective layer is omitted. Figure 2 for Figure 1 Schematic diagram of a cross-sectional structure along the EE1 direction, the surface acoustic wave resonator device includes: a substrate 100; an intermediate layer 101 located on the substrate 100; a piezoelectric layer 102 located on the intermediate layer 101; an interdigitated electrode structure 103 located on the piezoelectric layer 102, the interdigitated electrode structure 103 including a first bus 1030, a plurality of first electrode strips 1031, a plurality of second electrode strips 1032 and a second bus 1034, the plurality of first electrode strips 1031 and the plurality of second electrode strips 1032 are parallel to the first direction X , and the first electrode strips 1031 and the second electrode strips 1032 are arranged at intervals along the second direction, a number of first electrode strips 1031 are electrically connected to the first bus 1030, a number of second electrode strips 1032 are electrically connected to the second bus 1034, a first gap area g1 is provided between the first bus 1030 and the number of the second electrode strips 1032, and a second gap area g2 is provided between the second bus 1034 and the number of the first electrode strips 1031; a protective layer 104 is located on the surface of the interdigitated electrode structure 103.

[0038] In the above-mentioned surface acoustic wave resonator device, along the first direction X, due to the large surface acoustic wave velocity in the first gap region g1 (the second gap region g2), the acoustic wave energy will leak from the end of the second electrode strip 1032 (the first electrode strip 1031) to the first gap region g1 (the second gap region g2) (e.g. Figure 1 The quality factor (Q) of the surface acoustic wave resonator decreases.

[0039] In order to solve the above problems, the technical solution of the present invention provides a surface acoustic wave resonant device and a method for forming the same, wherein the first dummy finger layer and the second dummy finger layer are located in the intermediate layer, the first dummy finger layer is located on the first gap area, and the second dummy finger layer is located on the second gap area, the first dummy finger portion has a first projection on the substrate surface, the first electrode strip has a second projection on the substrate surface, the second dummy finger portion has a third projection on the substrate surface, and the second electrode strip has a fourth projection on the substrate surface, the first projection and the fourth projection are arranged along the first direction, and the second projection and the third projection are arranged along the first direction, the first dummy finger layer reduces the speed of sound in the first gap area, which is beneficial to suppressing the leakage of sound waves through the end of the second electrode strip to the outside, and the second dummy finger layer reduces the speed of sound in the second gap area, which is beneficial to suppressing the leakage of sound waves through the end of the first electrode strip to the outside, thereby helping to improve the quality factor of the surface acoustic wave resonant device.

[0040] In order to make the above-mentioned objects, features and beneficial effects of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0041] Figures 3 to 13 It is a structural diagram of the formation process of the surface acoustic wave resonator device in one embodiment of the present invention.

[0042] Please refer to Figure 3 and Figure 4 , Figure 3 A schematic diagram of the structure from above. Figure 4 for Figure 3 A schematic diagram of the cross-sectional structure along the MM1 direction is provided, providing a substrate 200, wherein the surface of the substrate 200 includes a first bus area L1, a first gap area G1, an overlap area C, a second gap area G2 and a second bus area L2 arranged along a first direction X, the first gap area G1 is located between the first bus area L1 and the overlap area C, and the second gap area G2 is located between the second bus area L2 and the overlap area C.

[0043] The material of the substrate 200 includes silicon, sapphire, spinel or silicon carbide. In this embodiment, the material of the substrate 200 is silicon.

[0044] Please refer to Figures 5 to 7 , Figure 5 The top view of the structure of the intermediate layer 201 is omitted. Figure 6 for Figure 5 Schematic diagram of the cross-sectional structure along the MM1 direction, Figure 7 for Figure 5 The schematic diagram of the cross-sectional structure along the NN1 direction forms an intermediate layer 201, a first dummy finger layer 202 and a second dummy finger layer 203, the first dummy finger layer 202 and the second dummy finger layer 203 are located in the intermediate layer 201, and the first dummy finger layer 202 is located on the first gap area G1, and the second dummy finger layer 203 is located on the second gap area G2, the first dummy finger layer 202 includes a plurality of first dummy finger portions 2021, and the second dummy finger layer 203 includes a plurality of second dummy finger portions 2032, the plurality of first dummy finger portions 2021 and the plurality of second dummy finger portions 2032 are all parallel to the first direction X, and are arranged along the second direction Y respectively, and the first direction X and the second direction Y are different.

[0045] In this embodiment, the first dummy finger layer 202 and the second dummy finger layer 203 are located in the middle layer 201 and are covered by the middle layer 201 .

[0046] In another embodiment, the first dummy finger layer and the second dummy finger layer are located in the middle layer, and the middle layer may expose a surface of one or both of the first dummy finger layer and the second dummy finger layer.

[0047] In this embodiment, the first direction X and the second direction Y are perpendicular to each other.

[0048] In this embodiment, the first dummy finger layer 202 further extends onto a portion of the first bus region L1, and the second dummy finger layer 203 further extends onto a portion of the second bus region L2. Extending the first dummy finger layer 202 onto a portion of the first bus region L1 and the second dummy finger layer 203 onto a portion of the second bus region L2 helps improve the process window.

[0049] In other embodiments, the first dummy finger layer may not extend onto a portion of the first bus region L1 , and the second dummy finger layer may not further extend onto a portion of the second bus region.

[0050] In this embodiment, the intermediate layer 201 has a first surface (not shown) and a second surface (not shown) facing each other. The first surface is adjacent to the substrate 200, and the second surface is adjacent to the piezoelectric layer. The first dummy finger layer 202 has a fifth spacing from the first surface, and a sixth spacing from the second surface, which is smaller than the fifth spacing. The second dummy finger layer 203 has a seventh spacing from the first surface, and an eighth spacing from the second surface, which is smaller than the seventh spacing. Placing the first and second dummy finger layers 202, 203 closer to the piezoelectric layer helps increase their influence on the speed of sound.

[0051] The material density of the first dummy finger layer 202 and the second dummy finger layer 203 is greater than the material density of the intermediate layer. The material of the first dummy finger layer 202 and the second dummy finger layer 203 includes a dielectric material or a metal material. In this embodiment, the first dummy finger layer 202 and the second dummy finger layer 203 are both made of metal.

[0052] The metal material includes one or more of aluminum, copper, molybdenum and platinum. In this embodiment, the first dummy finger layer 202 and the second dummy finger layer 203 are both made of molybdenum.

[0053] The material of the intermediate layer 201 includes silicon dioxide, silicon oxynitride, or silicon oxide containing dopants, and the dopant includes one or both of carbon and fluorine.

[0054] In this embodiment, the material of the intermediate layer 201 is silicon dioxide. Here, the intermediate layer 201 also plays a role of temperature compensation.

[0055] In this embodiment, the intermediate layer 201 has a first thickness, and a ratio of the first thickness to the wavelength of the acoustic wave excited by the interdigital electrode structure is in a range of 0.1 to 10.

[0056] It should be noted that the thickness referred to herein is the dimension perpendicular to the surface of the substrate 200 .

[0057] In this embodiment, the first dummy finger layer 202 and the second dummy finger layer 203 are located at the same height.

[0058] In this embodiment, the method for forming the intermediate layer 201, the first dummy finger layer 202 and the second dummy finger layer 203 includes: forming a first bonding material layer 2011 on the surface of the substrate 200; forming a dummy finger material layer (not shown in the figure) on the first bonding material layer 2011; patterning the dummy finger material layer to form the first dummy finger layer 202 and the second dummy finger layer 203; forming a second bonding material layer 2012 on the surface of the first bonding material layer, the first dummy finger layer 202 and the second dummy finger layer 203, covering the first bonding material layer 2011, the first dummy finger layer 202 and the second dummy finger layer 203, with the first bonding material layer 2011 and the second bonding material layer 2012 serving as the intermediate layer 201.

[0059] Please refer to Figures 8 to 10 , Figure 8 Schematic diagram of the top view of the structure (dashed lines are used to indicate the positions of the first dummy finger layer 202 and the second dummy finger layer 203). Figure 9 for Figure 8 Schematic diagram of the cross-sectional structure along the MM1 direction, Figure 10 for Figure 8 The cross-sectional structural diagram along the NN1 direction in the figure provides a piezoelectric layer 204 ; the substrate 200 and the piezoelectric layer 204 are bonded through the intermediate layer 201 , and the substrate 200 and the piezoelectric layer 204 are located on both sides of the intermediate layer 201 .

[0060] In this embodiment, joining the substrate 200 and the piezoelectric layer 204 through the intermediate layer 201 includes: bonding the intermediate layer 201 and the piezoelectric layer 204 .

[0061] In another embodiment, the first pseudo-finger layer and the second pseudo-finger layer are located at the same height; the method for forming the intermediate layer, the first pseudo-finger layer and the second pseudo-finger layer includes: forming a first bonding material layer on the surface of the substrate; forming a second bonding material layer on the surface of the piezoelectric layer; forming a pseudo-finger material layer on the second bonding material layer; patterning the pseudo-finger material layer to form the first pseudo-finger layer and the second pseudo-finger layer; forming a third bonding material layer on the surface of the second bonding material layer, the first pseudo-finger layer and the second pseudo-finger layer; bonding the substrate and the piezoelectric layer through the intermediate layer includes: bonding the first bonding material layer and the third bonding material layer to bond the substrate and the piezoelectric layer, with the first bonding material layer, the second bonding material layer and the third bonding material layer as the intermediate layer.

[0062] In another embodiment, the first pseudo-finger layer and the second pseudo-finger layer are located at the same height; the method for forming the intermediate layer, the first pseudo-finger layer and the second pseudo-finger layer includes: forming a first bonding material layer on the surface of the substrate; forming a pseudo-finger material layer on the first bonding material layer; patterning the pseudo-finger material layer to form the first pseudo-finger layer and the second pseudo-finger layer; forming a second bonding material layer on the surface of the first bonding material layer, the first pseudo-finger layer and the second pseudo-finger layer; forming a third bonding material layer on the surface of the piezoelectric layer; bonding the substrate and the piezoelectric layer through the intermediate layer includes: bonding the second bonding material layer and the third bonding material layer to bond the substrate and the piezoelectric layer, with the first bonding material layer, the second bonding material layer and the third bonding material layer as the intermediate layer.

[0063] In another embodiment, the first pseudo-finger layer and the second pseudo-finger layer are located at different heights; the method for forming the intermediate layer, the first pseudo-finger layer and the second pseudo-finger layer includes: forming a first bonding material layer on the surface of the substrate; forming a first pseudo-finger material layer on the first bonding material layer; patterning the first pseudo-finger material layer to form the first pseudo-finger layer; forming a second bonding material layer on the surface of the first bonding material layer and the first pseudo-finger layer; forming a second pseudo-finger material layer on the surface of the second bonding material layer; patterning the second pseudo-finger material layer to form the second pseudo-finger layer; forming a third bonding material layer on the surface of the second pseudo-finger layer and the surface of the second bonding material layer, and forming the intermediate layer with the first bonding material layer, the second bonding material layer and the third bonding material layer; joining the substrate and the piezoelectric layer through the intermediate layer includes: bonding the intermediate layer and the piezoelectric layer.

[0064] In another embodiment, the first pseudo-finger layer and the second pseudo-finger layer are located at different heights; the method for forming the intermediate layer, the first pseudo-finger layer and the second pseudo-finger layer includes: forming a first bonding material layer on the surface of the substrate; forming a first pseudo-finger material layer on the first bonding material layer; patterning the first pseudo-finger material layer to form the first pseudo-finger layer; forming a second bonding material layer on the surface of the first bonding material layer and the first pseudo-finger layer; forming a second pseudo-finger material layer on the surface of the second bonding material layer; patterning the second pseudo-finger material layer to form the second pseudo-finger layer; forming a third bonding material layer on the surface of the second pseudo-finger layer and the surface of the second bonding material layer; forming a fourth bonding material layer on the surface of the piezoelectric layer; bonding the substrate and the piezoelectric layer through the intermediate layer includes: bonding the third bonding material layer and the fourth bonding material layer to bond the substrate and the piezoelectric layer, with the first bonding material layer, the second bonding material layer, the third bonding material layer and the fourth bonding material layer as the intermediate layer.

[0065] In another embodiment, the first pseudo-finger layer and the second pseudo-finger layer are located at different heights; the method for forming the intermediate layer, the first pseudo-finger layer and the second pseudo-finger layer includes: forming a first bonding material layer on the surface of the substrate; forming a second bonding material layer on the surface of the piezoelectric layer; forming a first pseudo-finger material layer on the second bonding material layer; patterning the first pseudo-finger material layer to form the first pseudo-finger layer; forming a third bonding material layer on the second bonding material layer and the first pseudo-finger layer surface; forming a second pseudo-finger material layer on the surface of the third bonding material layer; patterning the second pseudo-finger material layer to form the second pseudo-finger layer; forming a fourth bonding material layer on the surface of the second pseudo-finger layer and the surface of the third bonding material layer; bonding the substrate and the piezoelectric layer through the intermediate layer includes: bonding the first bonding material layer and the fourth bonding material layer to bond the substrate and the piezoelectric layer, with the first bonding material layer, the second bonding material layer, the third bonding material layer and the fourth bonding material layer as the intermediate layer.

[0066] The material of the piezoelectric layer 204 includes lithium tantalate, lithium niobate, aluminum nitride or zinc oxide. In this embodiment, the material of the piezoelectric layer 204 is lithium tantalate.

[0067] In this embodiment, the piezoelectric layer 204 has a second thickness, and a ratio of the second thickness to the wavelength of the acoustic wave excited by the interdigital electrode structure is in a range of 0.1 to 20.

[0068] Please refer to Figures 11 to 13 , Figure 11 Schematic diagram of the top view of the structure (dashed lines are used to indicate the positions of the first dummy finger layer 202 and the second dummy finger layer 203). Figure 12 for Figure 11 Schematic diagram of the cross-sectional structure along the MM1 direction, Figure 13 for Figure 11 Schematic diagram of the cross-sectional structure along the NN1 direction, an interdigitated electrode structure is formed on the surface of the piezoelectric layer 204, the interdigitated electrode structure includes a first bus 2051, a second bus 2052, a plurality of first electrode strips 2061 and a plurality of second electrode strips 2062, a plurality of the first electrode strips 2061 are connected to the first bus 2051, a plurality of the second electrode strips 2062 are connected to the second bus 2052, a plurality of the first electrode strips 2061 and a plurality of the second electrode strips 2062 are parallel to the first direction X and arranged along the second direction Y, the first electrode strips 2061 and the second electrode strips 2062 are arranged alternately, the first bus 2051 is located on the first bus area L1, the second bus 2052 is located on the second bus area L2, and a plurality of the first electrode strips 2061 and the second electrode strips 2062 are arranged alternately. The first electrode strip 2061 is located on the first gap area G1 and the overlapping area C, and several second electrode strips 2062 are located on the overlapping area C and the second gap area G2. Several first electrode strips 2061 and several second electrode strips 2062 on the overlapping area C overlap along the second direction Y. The first fake finger portion 2021 has a first projection on the surface of the substrate 200, the first electrode strip 2061 has a second projection on the surface of the substrate 200, the second fake finger portion 2032 has a third projection on the surface of the substrate 200, and the second electrode strip 2062 has a fourth projection on the surface of the substrate 200. The first projection and the fourth projection are arranged along the first direction X, and the second projection and the third projection are arranged along the first direction X.

[0069] At this point, the first pseudo-finger layer 202 reduces the speed of sound in the first gap area G1, which is beneficial to suppressing the leakage of sound waves to the outside through the end of the second electrode strip 2062. The second pseudo-finger layer 203 reduces the speed of sound in the second gap area G2, which is beneficial to suppressing the leakage of sound waves to the outside through the end of the first electrode strip 2061, and further helps to improve the quality factor of the surface acoustic wave resonator device.

[0070] In this embodiment, a plurality of first electrode strips 2061 and a plurality of second electrode strips 2062 are uniformly arranged along the second direction Y with an arrangement period, and the arrangement period is the center distance between adjacent first electrode strips 2061, or the center distance between adjacent second electrode strips 2062, and the arrangement period is equal to the wavelength of the sound wave excited by the interdigitated electrode structure.

[0071] In this embodiment, the first projections and the second projections are alternately arranged along the second direction Y; the third projections and the fourth projections are alternately arranged along the second direction Y.

[0072] In this embodiment, along the first direction X, there is a first spacing d1 between the first projection and the fourth projection, and the ratio of the first spacing d1 to the wavelength of the acoustic wave excited by the interdigitated electrode structure is in the range of 0.01 to 1; along the first direction X, there is a second spacing d2 between the second projection and the third projection, and the ratio of the second spacing d2 to the wavelength of the acoustic wave excited by the interdigitated electrode structure is in the range of 0.01 to 1.

[0073] In this embodiment, the first dummy finger layer 202 on the first gap area G1 has a first length h1 along the first direction X, and a third spacing d3 is present between the first bus 2051 and the second electrode strip 2062 along the first direction X, and the first length h1 is smaller than the third spacing d3; the second dummy finger layer 203 on the second gap area G2 has a second length h2 along the first direction X, and a fourth spacing d4 is present between the second bus 2052 and the first electrode strip 2061 along the first direction X, and the second length h2 is smaller than the fourth spacing d4.

[0074] In this embodiment, the ratio of the first length h1 to the wavelength of the acoustic wave excited by the interdigital electrode structure ranges from 0.01 to 2.5; the ratio of the second length h2 to the wavelength of the acoustic wave excited by the interdigital electrode structure ranges from 0.01 to 2.5.

[0075] In another embodiment, only the first length may be limited to be smaller than the third spacing without limiting the ratio between the first length and the wavelength of the acoustic wave excited by the interdigitated electrode structure, and only the second length may be limited to be smaller than the fourth spacing without limiting the ratio between the second length and the wavelength of the acoustic wave excited by the interdigitated electrode structure.

[0076] Accordingly, the embodiment of the present invention further provides a surface acoustic wave resonator device formed by the above method, please continue to refer to Figures 11 to 13, comprising: a substrate 200, wherein the surface of the substrate 200 comprises a first bus area L1, a first gap area G1, an overlap area C, a second gap area G2, and a second bus area L2 arranged along a first direction X, wherein the first gap area G1 is located between the first bus area L1 and the overlap area C, and the second gap area G2 is located between the second bus area L2 and the overlap area C; an intermediate layer 201, a first dummy finger layer 202, and a second dummy finger layer 203 located on the substrate 200, wherein the first dummy finger layer 202 and the second dummy finger layer 203 are located in the intermediate layer 201, the first dummy finger layer 202 is located on the first gap area G1, and the second dummy finger layer 203 is located between the first bus area L1 and the overlap area C. In the second gap region G2, the first dummy finger layer 202 includes a plurality of first dummy finger portions 2021, and the second dummy finger layer 203 includes a plurality of second dummy finger portions 2032, wherein the plurality of first dummy finger portions 2021 and the plurality of second dummy finger portions 2032 are parallel to the first direction X and are arranged along the second direction Y, respectively, and the first direction X and the second direction Y are different; the piezoelectric layer 204 is located on the intermediate layer 201, and the substrate 200 and the piezoelectric layer 204 are located on both sides of the intermediate layer 201; an interdigitated electrode structure is located on the surface of the piezoelectric layer 204, and the interdigitated electrode structure includes a first bus 2051, a second bus 2052, and a plurality of first electrode strips 2051, a second bus 2052, and a plurality of first electrode strips 2052. 61 and a plurality of second electrode strips 2062, a plurality of first electrode strips 2061 are connected to the first bus 2051, a plurality of second electrode strips 2062 are connected to the second bus 2052, a plurality of first electrode strips 2061 and a plurality of second electrode strips 2062 are parallel to the first direction X and arranged along the second direction Y, the first electrode strips 2061 and the second electrode strips 2062 are arranged alternately, the first bus 2051 is located on the first bus area L1, the second bus 2052 is located on the second bus area L2, a plurality of first electrode strips 2061 are located on the first gap area G1 and the overlap area C, a plurality of second The electrode strips 2062 are located on the overlapping area C and the second gap area G2. Several of the first electrode strips 2061 and several of the second electrode strips 2062 on the overlapping area C overlap along the second direction Y. The first fake finger portion 2021 has a first projection on the surface of the substrate 200, the first electrode strip 2061 has a second projection on the surface of the substrate 200, the second fake finger portion 2032 has a third projection on the surface of the substrate 200, and the second electrode strip 2062 has a fourth projection on the surface of the substrate 200. The first projection and the fourth projection are arranged along the first direction X, and the second projection and the third projection are arranged along the first direction X.

[0077] In this embodiment, the first dummy finger layer 202 and the second dummy finger layer 203 are located in the middle layer 201 and are covered by the middle layer 201 .

[0078] In another embodiment, the first dummy finger layer and the second dummy finger layer are located in the middle layer, and the middle layer may expose a surface of one or both of the first dummy finger layer and the second dummy finger layer.

[0079] In this embodiment, the first direction X and the second direction Y are perpendicular to each other.

[0080] In this embodiment, the first projections and the second projections are alternately arranged along the second direction Y; and the third projections and the fourth projections are alternately arranged along the second direction.

[0081] In this embodiment, along the first direction X, there is a first spacing d1 between the first projection and the fourth projection, and the ratio of the first spacing d1 to the wavelength of the acoustic wave excited by the interdigitated electrode structure is in the range of 0.01 to 1; along the first direction X, there is a second spacing d2 between the second projection and the third projection, and the ratio of the second spacing d2 to the wavelength of the acoustic wave excited by the interdigitated electrode structure is in the range of 0.01 to 1.

[0082] In this embodiment, the first dummy finger layer 202 on the first gap area G1 has a first length h1 along the first direction X, and a third spacing d3 is present between the first bus 2051 and the second electrode strip 2062 along the first direction X, and the first length h1 is smaller than the third spacing d3; the second dummy finger layer 203 on the second gap area G2 has a second length h2 along the first direction X, and a fourth spacing d4 is present between the second bus 2052 and the first electrode strip 2061 along the first direction X, and the second length h2 is smaller than the fourth spacing d4.

[0083] In this embodiment, the ratio of the first length h1 to the wavelength of the acoustic wave excited by the interdigital electrode structure ranges from 0.01 to 2.5; the ratio of the second length h2 to the wavelength of the acoustic wave excited by the interdigital electrode structure ranges from 0.01 to 2.5.

[0084] In another embodiment, only the first length may be limited to be smaller than the third spacing without limiting the ratio between the first length and the wavelength of the acoustic wave excited by the interdigitated electrode structure, and only the second length may be limited to be smaller than the fourth spacing without limiting the ratio between the second length and the wavelength of the acoustic wave excited by the interdigitated electrode structure.

[0085] In this embodiment, the intermediate layer 201 has a first surface (not shown) and a second surface (not shown) facing each other. The first surface is adjacent to the substrate 200, and the second surface is adjacent to the piezoelectric layer. The first dummy finger layer 202 has a fifth spacing from the first surface, and a sixth spacing from the second surface, which is smaller than the fifth spacing. The second dummy finger layer 203 has a seventh spacing from the first surface, and an eighth spacing from the second surface, which is smaller than the seventh spacing. Placing the first and second dummy finger layers 202, 203 closer to the piezoelectric layer helps increase their influence on the speed of sound.

[0086] The material density of the first dummy finger layer 202 and the second dummy finger layer 203 is greater than the material density of the intermediate layer 201. The material of the first dummy finger layer 202 and the second dummy finger layer 203 includes a dielectric material or a metal material. In this embodiment, the first dummy finger layer 202 and the second dummy finger layer 203 are both made of metal.

[0087] The metal material includes one or more of aluminum, copper, molybdenum and platinum. In this embodiment, the first dummy finger layer 202 and the second dummy finger layer 203 are both made of molybdenum.

[0088] The material of the intermediate layer 201 includes silicon dioxide, silicon oxynitride, or silicon oxide containing a dopant, wherein the dopant includes one or both of carbon and fluorine. In this embodiment, the material of the intermediate layer 201 is silicon dioxide. Here, the intermediate layer 201 also plays a role in temperature compensation.

[0089] In this embodiment, the first dummy finger layer 202 and the second dummy finger layer 203 are located at the same height.

[0090] In another embodiment, the first dummy finger layer and the second dummy finger layer may be located at different heights.

[0091] In this embodiment, the intermediate layer 201 has a first thickness, and a ratio of the first thickness to the wavelength of the acoustic wave excited by the interdigital electrode structure is in a range of 0.1 to 10.

[0092] In this embodiment, the piezoelectric layer 204 has a second thickness, and a ratio of the second thickness to the wavelength of the acoustic wave excited by the interdigital electrode structure is in a range of 0.1 to 20.

[0093] Figures 14 to 19 It is a structural schematic diagram of the formation process of a surface acoustic wave resonator device in another embodiment of the present invention.

[0094] Please refer to Figures 14 to 16 , Figure 14 The top view of the structure of the intermediate layer 301 is omitted. Figure 15 for Figure 14 Schematic diagram of the cross-section structure along the OO1 direction, Figure 16 for Figure 14 A schematic cross-sectional structure diagram along the PP1 direction is provided, wherein a substrate 300 is provided, wherein the surface of the substrate 300 includes a first bus area L1, a first gap area G1, an overlap area C, a second gap area G2, and a second bus area L2 arranged along a first direction X, wherein the first gap area G1 is located between the first bus area L1 and the overlap area C, and the second gap area G2 is located between the second bus area L2 and the overlap area C; an intermediate layer 301, a first dummy finger layer 302, and a second dummy finger layer 303 are formed, wherein the first dummy finger layer 302 and the second dummy finger layer 303 are formed. 3 is located in the intermediate layer 301 and is covered by the intermediate layer 301, and the first dummy finger layer 302 is located on the first gap area G1, and the second dummy finger layer 303 is located on the second gap area G2. The first dummy finger layer 302 includes a plurality of first dummy finger portions 3021, and the second dummy finger layer 303 includes a plurality of second dummy finger portions 3032. The plurality of first dummy finger portions 3021 and the plurality of second dummy finger portions 3032 are both parallel to the first direction X and are respectively arranged along a second direction Y. The first direction X and the second direction Y are different.

[0095] In this embodiment, the first direction X and the second direction Y are perpendicular to each other.

[0096] This embodiment is different from the previous embodiment (such as Figure 5 The main differences are:

[0097] In this embodiment, forming the first dummy finger layer 302 also includes forming a plurality of third dummy finger portions 3023, wherein the third dummy finger portions 3023 and the first dummy finger portions 3021 are alternately arranged along the second direction Y, and one first electrode strip will be formed on one of the third dummy finger portions 3023; forming the second dummy finger layer 303 also includes forming a plurality of fourth dummy finger portions 3034, wherein the fourth dummy finger portions 3034 and the second dummy finger portions 3032 are alternately arranged along the second direction Y, and one second electrode strip will be formed on one of the fourth dummy finger portions 3034.

[0098] In this embodiment, the third dummy finger portion 3023 is formed simultaneously with the formation of the first dummy finger portion 3021 ; and the fourth dummy finger portion 3034 is formed simultaneously with the formation of the second dummy finger portion 3032 .

[0099] More specifically, the first fake finger portion 3021 , the second fake finger portion 3032 , the third fake finger portion 3023 and the fourth fake finger portion 3034 are formed simultaneously.

[0100] In another embodiment, the first dummy finger portion and the third dummy finger portion are formed simultaneously, and the second dummy finger portion and the fourth dummy finger portion are formed simultaneously.

[0101] In yet another embodiment, the first dummy finger portion, the second dummy finger portion, the third dummy finger portion, and the fourth dummy finger portion may be formed separately.

[0102] Here, the formation method of the intermediate layer 301 , the first dummy finger portion 3021 , the second dummy finger portion 3032 , the third dummy finger portion 3023 and the fourth dummy finger portion 3034 may refer to the description of the previous embodiment and will not be repeated here.

[0103] Please refer to Figures 17 to 19 , Figure 17 Schematic diagram of the top view of the structure (dashed lines are used to indicate the positions of the first dummy finger layer 302 and the second dummy finger layer 303). Figure 18 for Figure 17 Schematic diagram of the cross-section structure along the OO1 direction, Figure 19 for Figure 17 A schematic cross-sectional structure diagram along the PP1 direction in the middle is provided, wherein a piezoelectric layer 304 is provided; the substrate 300 and the piezoelectric layer 304 are bonded via the intermediate layer 301, and the substrate 300 and the piezoelectric layer 304 are located on both sides of the intermediate layer 301; an interdigitated electrode structure is formed on the surface of the piezoelectric layer 304, wherein the interdigitated electrode structure includes a first bus 3051, a second bus 3052, a plurality of first electrode strips 3061, and a plurality of second electrode strips 3062, wherein the plurality of first electrode strips 3061 are connected to the first bus 3051, the plurality of second electrode strips 3062 are connected to the second bus 3052, and the plurality of first electrode strips 3061 are connected to the first bus 3051. and several second electrode strips 3062 are parallel to the first direction X and arranged along the second direction Y, the first electrode strips 3061 and the second electrode strips 3062 are arranged alternately, the first bus 3051 is located on the first bus area L1, the second bus 3052 is located on the second bus area L2, several first electrode strips 3061 are located on the first gap area G1 and the overlapping area C, several second electrode strips 3062 are located on the overlapping area C and the second gap area G2, and several first electrode strips 3061 and several second electrode strips 3062 on the overlapping area C overlap along the second direction Y.

[0104] One of the first electrode strips 3061 is located on one of the third dummy finger portions 3023 , and one of the second electrode strips 3062 is located on one of the fourth dummy finger portions 3034 .

[0105] The first fake finger portion 3021 has a first projection on the surface of the substrate 300, the first electrode strip 3061 has a second projection on the surface of the substrate 200, the second fake finger portion 3032 has a third projection on the surface of the substrate 300, and the second electrode strip 3062 has a fourth projection on the surface of the substrate 300. The first projection and the fourth projection are arranged along the first direction X, and the second projection and the third projection are arranged along the first direction X.

[0106] The third fake finger portion 3023 has a fifth projection on the surface of the substrate 300 , and the fourth fake finger portion 3034 has a sixth projection on the surface of the substrate 300 . The fifth projection overlaps with the second projection, and the sixth projection overlaps with the fourth projection.

[0107] At this point, the first pseudo-finger layer 302 reduces the speed of sound in the first gap area G1, which is beneficial to suppressing the leakage of sound waves through the end of the second electrode strip 3062 to the outside, and the second pseudo-finger layer 303 reduces the speed of sound in the second gap area G2, which is beneficial to suppressing the leakage of sound waves through the end of the first electrode strip 3061 to the outside, and further helps to improve the quality factor of the surface acoustic wave resonant device; a number of third pseudo-finger parts 3023 and a number of fourth pseudo-finger parts 3034 can further suppress the leakage of sound waves through the end of the second electrode strip 3062 or the end of the first electrode strip 3061 to the outside, thereby further helping to improve the quality factor of the surface acoustic wave resonant device.

[0108] It should be noted that, except for the first dummy finger layer 302 and the second dummy finger layer 303 , the structure and formation method of the surface acoustic wave resonator device can be referred to the description of the previous embodiment and will not be elaborated here.

[0109] Accordingly, the embodiment of the present invention further provides a surface acoustic wave resonator device formed by the above method, please continue to refer to Figures 17 to 19, comprising: a substrate 300, wherein the surface of the substrate 300 comprises a first bus area L1, a first gap area G1, an overlap area C, a second gap area G2, and a second bus area L2 arranged along a first direction X, wherein the first gap area G1 is located between the first bus area L1 and the overlap area C, and the second gap area G2 is located between the second bus area L2 and the overlap area C; an intermediate layer 301, a first dummy finger layer 302, and a second dummy finger layer 303 located on the substrate 300, wherein the first dummy finger layer 302 and the second dummy finger layer 303 are located in the intermediate layer 301 and are covered by the intermediate layer 301, the first dummy finger layer 302 is located on the first gap area G1, and the second The dummy finger layer 303 is located on the second gap region G2, the first dummy finger layer 302 includes a plurality of first dummy finger portions 3021, the second dummy finger layer 303 includes a plurality of second dummy finger portions 3032, the plurality of first dummy finger portions 3021 and the plurality of second dummy finger portions 3032 are parallel to the first direction X and are arranged along the second direction Y respectively, the first direction X and the second direction Y are different; the piezoelectric layer 304 is located on the intermediate layer 301, the substrate 300 and the piezoelectric layer 304 are located on both sides of the intermediate layer 301; the interdigitated electrode structure is located on the surface of the piezoelectric layer 304, the interdigitated electrode structure includes a first bus 3051, a second bus 3052, and a plurality of second buses 3051, 3052, and a plurality of second buses 3052. An electrode strip 3061 and a plurality of second electrode strips 3062, a plurality of the first electrode strips 3061 are connected to the first bus 3051, a plurality of the second electrode strips 3062 are connected to the second bus 3052, a plurality of the first electrode strips 3061 and a plurality of the second electrode strips 3062 are parallel to the first direction X and arranged along the second direction Y, the first electrode strips 3061 and the second electrode strips 3062 are arranged alternately, the first bus 3051 is located on the first bus area L1, the second bus 3052 is located on the second bus area L2, a plurality of the first electrode strips 3061 are located on the first gap area G1 and the overlap area C, a plurality of The second electrode strips 3062 are located on the overlapping area C and the second gap area G2. Several of the first electrode strips 3061 and several of the second electrode strips 3062 on the overlapping area C overlap along the second direction Y. The first fake finger portion 3021 has a first projection on the surface of the substrate 300, the first electrode strip 3061 has a second projection on the surface of the substrate 300, the second fake finger portion 3032 has a third projection on the surface of the substrate 300, and the second electrode strip 3062 has a fourth projection on the surface of the substrate 300. The first projection and the fourth projection are arranged along the first direction X, and the second projection and the third projection are arranged along the first direction X.

[0110] In this embodiment, the first direction X and the second direction Y are perpendicular to each other.

[0111] In this embodiment, the first dummy finger layer 302 also includes a plurality of third dummy finger portions 3023, which are alternately arranged with the first dummy finger portion 3021 along the second direction Y, and a first electrode strip 3061 is located on one of the third dummy finger portions 3023; the second dummy finger layer 303 also includes a plurality of fourth dummy finger portions 3034, which are alternately arranged with the second dummy finger portion 3032 along the second direction Y, and a second electrode strip 3062 is located on one of the fourth dummy finger portions 3034.

[0112] At this point, the first pseudo-finger layer 302 reduces the speed of sound in the first gap area G1, which is beneficial to suppressing the leakage of sound waves through the end of the second electrode strip 3062 to the outside, and the second pseudo-finger layer 303 reduces the speed of sound in the second gap area G2, which is beneficial to suppressing the leakage of sound waves through the end of the first electrode strip 3061 to the outside, and further helps to improve the quality factor of the surface acoustic wave resonant device; a number of third pseudo-finger parts 3023 and a number of fourth pseudo-finger parts 3034 can further suppress the leakage of sound waves through the end of the second electrode strip 3062 or the end of the first electrode strip 3061 to the outside, thereby further helping to improve the quality factor of the surface acoustic wave resonant device.

[0113] It should be noted that, except for the first dummy finger layer 302 and the second dummy finger layer 303 , the structure of the surface acoustic wave resonator device can be referred to the description of the previous embodiment and will not be elaborated here.

[0114] 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 scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A surface acoustic wave resonator device, characterized in that: include: A substrate, wherein a surface of the substrate includes a first bus area, a first gap area, an overlap area, a second gap area, and a second bus area arranged along a first direction, the first gap area is located between the first bus area and the overlap area, and the second gap area is located between the second bus area and the overlap area; an intermediate layer, a first dummy finger layer, and a second dummy finger layer located on the substrate, wherein the first dummy finger layer and the second dummy finger layer are located within the intermediate layer, the first dummy finger layer is located on the first gap region, and the second dummy finger layer is located on the second gap region, the first dummy finger layer includes a plurality of first dummy finger portions, and the second dummy finger layer includes a plurality of second dummy finger portions, the plurality of first dummy finger portions and the plurality of second dummy finger portions are all parallel to the first direction and are respectively arranged along a second direction, and the first direction and the second direction are different; a piezoelectric layer located on the intermediate layer, wherein the substrate and the piezoelectric layer are located on both sides of the intermediate layer; an interdigitated electrode structure located on a surface of the piezoelectric layer, the interdigitated electrode structure comprising a first bus, a second bus, a plurality of first electrode strips, and a plurality of second electrode strips, wherein the plurality of first electrode strips are connected to the first bus, the plurality of second electrode strips are connected to the second bus, the plurality of first electrode strips and the plurality of second electrode strips are parallel to the first direction and arranged along the second direction, the first electrode strips and the second electrode strips are arranged alternately, the first bus is located on the first bus region, the second bus is located on the second bus region, the plurality of first electrode strips are located on the first gap region and the overlap region, the plurality of second electrode strips are located on the overlap region and the second gap region, and the plurality of first electrode strips and the plurality of second electrode strips in the overlap region overlap along the second direction; The first fake finger portion has a first projection on the substrate surface, the first electrode strip has a second projection on the substrate surface, the second fake finger portion has a third projection on the substrate surface, and the second electrode strip has a fourth projection on the substrate surface. The first projection and the fourth projection are arranged along the first direction, and the second projection and the third projection are arranged along the first direction.

2. The surface acoustic wave resonator device according to claim 1, wherein The first pseudo-finger layer also includes a plurality of third pseudo-finger portions, which are arranged alternately with the first pseudo-finger portions along the second direction, and one first electrode strip is located on one of the third pseudo-finger portions; the second pseudo-finger layer also includes a plurality of fourth pseudo-finger portions, which are arranged alternately with the second pseudo-finger portions along the second direction, and one second electrode strip is located on one of the fourth pseudo-finger portions.

3. The surface acoustic wave resonator device according to claim 1, wherein The first projections and the second projections are alternately arranged along the second direction; the third projections and the fourth projections are alternately arranged along the second direction.

4. The surface acoustic wave resonator device according to claim 1, wherein Along the first direction, there is a first distance between the first projection and the fourth projection, and a ratio of the first distance to the wavelength of the acoustic wave excited by the interdigital electrode structure is in a range of 0.01 to 1; Along the first direction, there is a second distance between the second projection and the third projection, and a ratio of the second distance to the wavelength of the acoustic wave excited by the interdigitated electrode structure is in a range of 0.01 to 1.

5. The surface acoustic wave resonator device according to claim 1, wherein The first dummy finger layer on the first gap region has a first length along the first direction, the first bus bar and the second electrode strip have a third spacing along the first direction, and the first length is smaller than the third spacing; The second dummy finger layer on the second gap region has a second length along the first direction, the second bus bar and the first electrode strip have a fourth distance along the first direction, and the second length is smaller than the fourth distance.

6. The surface acoustic wave resonator device according to claim 5, wherein: The ratio of the first length to the wavelength of the acoustic wave excited by the interdigital electrode structure is in the range of 0.01 to 2.5; the ratio of the second length to the wavelength of the acoustic wave excited by the interdigital electrode structure is in the range of 0.01 to 2.

5.

7. The surface acoustic wave resonator device according to claim 1, wherein The intermediate layer has a first surface and a second surface relative to each other, the first surface is adjacent to the substrate, and the second surface is adjacent to the piezoelectric layer; there is a fifth spacing between the first pseudo-finger layer and the first surface, and a sixth spacing between the first pseudo-finger layer and the second surface, and the sixth spacing is smaller than the fifth spacing; there is a seventh spacing between the second pseudo-finger layer and the first surface, and an eighth spacing between the second pseudo-finger layer and the second surface, and the eighth spacing is smaller than the seventh spacing.

8. The surface acoustic wave resonator device according to claim 1, wherein The material density of the first dummy finger layer and the second dummy finger layer is greater than the material density of the intermediate layer; the material of the first dummy finger layer and the second dummy finger layer includes a dielectric material or a metal material.

9. The surface acoustic wave resonator device according to claim 8, wherein The metal material includes a combination of one or more of aluminum, copper, molybdenum and platinum.

10. The surface acoustic wave resonator device according to claim 1, wherein The intermediate layer has a first thickness, and a ratio of the first thickness to a wavelength of an acoustic wave excited by the interdigital electrode structure is in a range of 0.1 to 10.

11. The surface acoustic wave resonator device according to claim 1, wherein The piezoelectric layer has a second thickness, and a ratio of the second thickness to a wavelength of an acoustic wave excited by the interdigital electrode structure ranges from 0.1 to 20.

12. A method for forming a surface acoustic wave resonator device, characterized in that: include: Providing a substrate, wherein a surface of the substrate includes a first bus area, a first gap area, an overlap area, a second gap area, and a second bus area arranged along a first direction, wherein the first gap area is located between the first bus area and the overlap area, and the second gap area is located between the second bus area and the overlap area; forming an intermediate layer, a first dummy finger layer, and a second dummy finger layer, wherein the first dummy finger layer and the second dummy finger layer are located within the intermediate layer, the first dummy finger layer is located on the first gap region, and the second dummy finger layer is located on the second gap region, the first dummy finger layer includes a plurality of first dummy finger portions, and the second dummy finger layer includes a plurality of second dummy finger portions, the plurality of first dummy finger portions and the plurality of second dummy finger portions are all parallel to the first direction and are respectively arranged along a second direction, and the first direction and the second direction are different; providing a piezoelectric layer; The substrate and the piezoelectric layer are bonded via the intermediate layer, wherein the substrate and the piezoelectric layer are located on both sides of the intermediate layer; An interdigitated electrode structure is formed on the surface of the piezoelectric layer, wherein the interdigitated electrode structure includes a first bus, a second bus, a plurality of first electrode strips and a plurality of second electrode strips, wherein the plurality of first electrode strips are connected to the first bus, and the plurality of second electrode strips are connected to the second bus, the plurality of first electrode strips and the plurality of second electrode strips are parallel to the first direction and arranged along the second direction, the first electrode strips and the second electrode strips are arranged alternately, the first bus is located on the first bus area, the second bus is located on the second bus area, the plurality of first electrode strips are located on the first gap area and the overlapping area, the plurality of second electrode strips are located on the overlapping area and the second gap area, the plurality of first electrode strips and the plurality of second electrode strips on the overlapping area overlap along the second direction, the first false finger portion has a first projection on the substrate surface, the first electrode strip has a second projection on the substrate surface, the second false finger portion has a third projection on the substrate surface, the second electrode strip has a fourth projection on the substrate surface, the first projection and the fourth projection are arranged along the first direction, and the second projection and the third projection are arranged along the first direction.

13. The method for forming a surface acoustic wave resonator device according to claim 12, wherein: The method for forming the intermediate layer, the first pseudo-finger layer and the second pseudo-finger layer includes: forming a first bonding material layer on the surface of the substrate; forming a pseudo-finger material layer on the first bonding material layer; patterning the pseudo-finger material layer to form the first pseudo-finger layer and the second pseudo-finger layer; forming a second bonding material layer on the surface of the first bonding material layer, the first pseudo-finger layer and the second pseudo-finger layer, covering the first bonding material layer, the first pseudo-finger layer and the second pseudo-finger layer, with the first bonding material layer and the second bonding material layer as the intermediate layer; joining the substrate and the piezoelectric layer through the intermediate layer includes: bonding the intermediate layer and the piezoelectric layer.

14. The method for forming a surface acoustic wave resonator device according to claim 12, wherein: The method for forming the intermediate layer, the first pseudo-finger layer and the second pseudo-finger layer includes: forming a first bonding material layer on the surface of the substrate; forming a second bonding material layer on the surface of the piezoelectric layer; forming a pseudo-finger material layer on the second bonding material layer; patterning the pseudo-finger material layer to form the first pseudo-finger layer and the second pseudo-finger layer; forming a third bonding material layer on the surfaces of the second bonding material layer, the first pseudo-finger layer and the second pseudo-finger layer; bonding the substrate and the piezoelectric layer through the intermediate layer includes: bonding the first bonding material layer and the third bonding material layer to bond the substrate and the piezoelectric layer, with the first bonding material layer, the second bonding material layer and the third bonding material layer as the intermediate layer.

15. The method for forming a surface acoustic wave resonator device according to claim 12, wherein: The method for forming the intermediate layer, the first pseudo-finger layer and the second pseudo-finger layer includes: forming a first bonding material layer on the surface of the substrate; forming a pseudo-finger material layer on the first bonding material layer; patterning the pseudo-finger material layer to form the first pseudo-finger layer and the second pseudo-finger layer; forming a second bonding material layer on the surfaces of the first bonding material layer, the first pseudo-finger layer and the second pseudo-finger layer; forming a third bonding material layer on the surface of the piezoelectric layer; bonding the substrate and the piezoelectric layer through the intermediate layer includes: bonding the second bonding material layer and the third bonding material layer to bond the substrate and the piezoelectric layer, with the first bonding material layer, the second bonding material layer and the third bonding material layer as the intermediate layer.

16. The method for forming a surface acoustic wave resonator device according to claim 12, wherein: The method for forming the intermediate layer, the first pseudo-finger layer and the second pseudo-finger layer includes: forming a first bonding material layer on the surface of the substrate; forming a first pseudo-finger material layer on the first bonding material layer; patterning the first pseudo-finger material layer to form the first pseudo-finger layer; forming a second bonding material layer on the surface of the first bonding material layer and the first pseudo-finger layer; forming a second pseudo-finger material layer on the surface of the second bonding material layer; patterning the second pseudo-finger material layer to form the second pseudo-finger layer; forming a third bonding material layer on the surface of the second pseudo-finger layer and the surface of the second bonding material layer, forming the intermediate layer with the first bonding material layer, the second bonding material layer and the third bonding material layer; joining the substrate and the piezoelectric layer through the intermediate layer includes: bonding the intermediate layer and the piezoelectric layer.

17. The method for forming a surface acoustic wave resonator device according to claim 12, wherein: The method for forming the intermediate layer, the first pseudo-finger layer and the second pseudo-finger layer includes: forming a first bonding material layer on the surface of the substrate; forming a first pseudo-finger material layer on the first bonding material layer; patterning the first pseudo-finger material layer to form the first pseudo-finger layer; forming a second bonding material layer on the surface of the first bonding material layer and the first pseudo-finger layer; forming a second pseudo-finger material layer on the surface of the second bonding material layer; patterning the second pseudo-finger material layer to form the second pseudo-finger layer; forming a third bonding material layer on the surface of the second pseudo-finger layer and the surface of the second bonding material layer; forming a fourth bonding material layer on the surface of the piezoelectric layer; bonding the substrate and the piezoelectric layer through the intermediate layer includes: bonding the third bonding material layer and the fourth bonding material layer to bond the substrate and the piezoelectric layer, with the first bonding material layer, the second bonding material layer, the third bonding material layer and the fourth bonding material layer as the intermediate layer.

18. The method for forming a surface acoustic wave resonator device according to claim 12, wherein: The method for forming the intermediate layer, the first pseudo-finger layer and the second pseudo-finger layer includes: forming a first bonding material layer on the surface of the substrate; forming a second bonding material layer on the surface of the piezoelectric layer; forming a first pseudo-finger material layer on the second bonding material layer; patterning the first pseudo-finger material layer to form the first pseudo-finger layer; forming a third bonding material layer on the surfaces of the second bonding material layer and the first pseudo-finger layer; forming a second pseudo-finger material layer on the surface of the third bonding material layer; patterning the second pseudo-finger material layer to form the second pseudo-finger layer; forming a fourth bonding material layer on the surfaces of the second pseudo-finger layer and the third bonding material layer; bonding the substrate and the piezoelectric layer through the intermediate layer includes: bonding the first bonding material layer and the fourth bonding material layer to bond the substrate and the piezoelectric layer, with the first bonding material layer, the second bonding material layer, the third bonding material layer and the fourth bonding material layer as the intermediate layer.

19. The method for forming a surface acoustic wave resonator device according to claim 12, wherein: Forming the first dummy finger layer also includes forming a plurality of third dummy finger portions, wherein the third dummy finger portions and the first dummy finger portions are alternately arranged along the second direction, and one of the first electrode strips is located on one of the third dummy finger portions; the method also includes: forming the third dummy finger portion at the same time as forming the first dummy finger portion.

20. The method for forming a surface acoustic wave resonator device according to claim 12, wherein: Forming the second dummy finger layer also includes forming a plurality of fourth dummy finger portions, wherein the fourth dummy finger portions and the second dummy finger portions are alternately arranged along the second direction, and one second electrode strip is located on one of the fourth dummy finger portions; the method also includes: forming the fourth dummy finger portion at the same time as forming the second dummy finger portion.

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