Resonant filter and manufacturing method thereof

Abstract

The invention discloses a resonant filter and a manufacturing method thereof. The resonant filter includes: a first substrate; the resonant filtering structure is formed on the first side of the first substrate, the resonant filtering structure comprises a bulk acoustic wave resonant structure and a lamb wave resonant structure, and the bulk acoustic wave resonant structure is electrically connected with the lamb wave resonant structure. Wherein the bulk acoustic wave resonance structure comprises a first electrode structure, the lamb wave resonance structure comprises a second electrode structure, and the first electrode structure and the second electrode structure share the same first electrode layer; or the bulk acoustic wave resonance structure and the Lamb wave resonance structure share the same piezoelectric layer.

Description

Technical Field

[0001] The present application relates to the field of semiconductor products and semiconductor process technology, and in particular to a resonant filter and a method for manufacturing the same. Background Art

[0002] BAW resonators have good bandpass performance, so BAW resonators can be used to achieve the passband performance of the filter. Lamb wave resonators have good stopband performance, so Lamb wave resonators can be used to achieve the stopband performance of the filter. In this case, if BAW resonators and Lamb wave resonators can be combined, the resonant filter circuit formed can flexibly configure the stopband frequency of the resonant filter circuit on the basis of achieving excellent bandpass performance. At present, BAW resonators and Lamb wave resonators are devices independently formed by their own processes, so the resonant filter circuit can only be constructed by combining independently formed BAW resonators and Lamb wave resonators.

[0003] Since both the BAW resonator and the Lamb wave resonator are independent resonant filter devices, the integration of the resonant filter circuit is low, and since the BAW resonator and the Lamb wave resonator are formed by respective processes, the process cost of constructing the resonant filter circuit is also very high.

[0004] With respect to the technical problems existing in the above-mentioned prior art that the resonant filter circuit composed of a bulk acoustic wave resonator and a Lamb wave resonator has low integration and high process cost, no effective solution has been proposed yet. Summary of the invention

[0005] The present disclosure provides a resonant filter and a manufacturing method thereof, so as to at least solve the technical problems existing in the prior art that a resonant filter circuit composed of a bulk acoustic wave resonator and a Lamb wave resonator has low integration and high process cost.

[0006] According to an embodiment of the present application, a resonant filter is provided, comprising: a first substrate; and a resonant filter structure formed on a first side of the first substrate, wherein the resonant filter structure comprises a bulk acoustic wave resonant structure and a Lamb wave resonant structure, and the bulk acoustic wave resonant structure and the Lamb wave resonant structure are electrically connected. The bulk acoustic wave resonant structure comprises a first electrode structure, and the Lamb wave resonant structure comprises a second electrode structure, wherein the first electrode structure and the second electrode structure share the same first electrode layer; or the bulk acoustic wave resonant structure and the Lamb wave resonant structure share the same piezoelectric layer.

[0007] According to another embodiment of the present application, a method for manufacturing a resonant filter is provided, comprising: manufacturing a first substrate used as a carrier and a resonant filter structure, wherein the resonant filter structure is formed on a first side of the first substrate, the resonant filter structure comprises a bulk acoustic wave resonant structure and a Lamb wave resonant structure, and the bulk acoustic wave resonant structure and the Lamb wave resonant structure are electrically connected. And wherein the bulk acoustic wave resonant structure comprises a first electrode structure, the Lamb wave resonant structure comprises a second electrode structure, wherein the first electrode structure and the second electrode structure share the same first electrode layer; or, the bulk acoustic wave resonant structure and the Lamb wave resonant structure share the same piezoelectric layer.

[0008] Optionally, the second electrode structure comprises interdigitated electrodes, and the first side of the piezoelectric layer adjoins the first electrode layer.

[0009] Optionally, the process of making the resonant filter structure further includes: making a second electrode layer on the second side of the piezoelectric layer; and using the second electrode layer to form a third electrode structure of a bulk acoustic wave resonance structure and a fourth electrode structure of a Lamb wave resonance structure. The third electrode structure corresponds to the first electrode structure, and the fourth electrode structure corresponds to the second electrode structure.

[0010] Optionally, the process of manufacturing the resonant filter structure further includes: forming a first resonant cavity between the bulk acoustic wave resonant structure and the first substrate, and forming a second resonant cavity between the Lamb wave resonant structure and the first substrate.

[0011] Optionally, the method further comprises: bonding the second substrate to the resonant filter structure using a bonding layer, wherein the second substrate comprises a central region and an edge region, wherein the central region covers the bulk acoustic wave resonant structure and the Lamb wave resonant structure; and the bonding layer corresponds to the edge region of the first side of the second substrate.

[0012] Optionally, the method further comprises forming a conductive electrode on the second side of the second substrate electrically connected to the BAW resonance structure and the Lamb wave resonance structure.

[0013] Optionally, the process of forming a conductive electrode electrically connected to the bulk acoustic wave resonance structure and the Lamb wave resonance structure on the second side of the second substrate further includes: forming a first conductive electrode and a second conductive electrode on the second side of the second substrate, wherein the first conductive electrode is electrically connected to the second electrode layer via a through hole conduction, and the second conductive electrode is electrically connected to the first interdigital electrode of the second electrode structure via a through hole conduction.

[0014] Optionally, the process of forming a conductive electrode electrically connected to the bulk acoustic wave resonance structure and the Lamb wave resonance structure on the second side of the second substrate further includes: forming a first conductive electrode, a second conductive electrode and a third conductive electrode on the second side of the second substrate. And wherein the first conductive electrode is electrically connected to the second electrode layer via a through-hole conduction, the second conductive electrode is electrically connected to the first interdigital electrode of the second electrode structure via a through-hole conduction, and the third conductive electrode is electrically connected to the second interdigital electrode of the first electrode structure and the second electrode structure via a through-hole conduction.

[0015] Optionally, the method further includes forming a conductive electrode electrically connected to the bulk acoustic wave resonance structure and the Lamb wave resonance structure on the second side of the first substrate.

[0016] Optionally, the process of forming a conductive electrode electrically connected to the bulk acoustic wave resonance structure and the Lamb wave resonance structure on the second side of the first substrate includes forming a fourth conductive electrode and a fifth conductive electrode on the second side of the first substrate, wherein the fourth conductive electrode is electrically connected to the second electrode layer via a through hole; and the fifth conductive electrode is electrically connected to the first interdigital electrode of the second electrode structure via a through hole.

[0017] Optionally, the process of forming a conductive electrode electrically connected to the bulk acoustic wave resonance structure and the Lamb wave resonance structure on the second side of the first substrate includes forming a fourth conductive electrode, a fifth conductive electrode and a sixth conductive electrode on the second side of the first substrate. The fourth conductive electrode is electrically connected to the second electrode layer via a through-hole conduction; the fifth conductive electrode is electrically connected to the first interdigital electrode of the second electrode structure via a through-hole conduction; and the sixth conductive electrode is electrically connected to the second interdigital electrode of the first electrode structure and the second electrode structure via a through-hole conduction.

[0018] Thus, according to the embodiment of the present application, in the resonant filter, the bulk acoustic wave resonant structure and the Lamb wave resonant structure share the same substrate, and the bulk acoustic wave resonant structure and the Lamb wave resonant structure also share the same electrode layer or piezoelectric layer. Thus, in this way, the present embodiment integrates the bulk acoustic wave resonant structure and the Lamb wave resonant structure into a resonant filter structure, and then integrates them into the same resonant filter device, thereby improving the integration of the resonant filter circuit. And the method for manufacturing the resonant filter can simultaneously manufacture the bulk acoustic wave resonant structure and the Lamb wave resonant structure in the same set of processing processes, thereby reducing the process cost of constructing the resonant filter circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Hereinafter, some specific embodiments of the present application will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the accompanying drawings: Figure 1is a schematic diagram of the layer structure of the resonant filter according to Embodiment 1 of the present application; Figure 2 is a schematic top view of the resonant filter according to Embodiment 1 of the present application; Figure 3 is a circuit diagram of a resonant filter according to Embodiment 1 of the present application; Figure 4~Figure 6 is a schematic diagram of a resonant filter according to a modified example of Embodiment 1 of the present application; Figure 7 is a schematic diagram of a resonant filter according to another modified example of Embodiment 1 of the present application; Figure 8 is a schematic diagram of a resonant filter according to another modified example of Embodiment 1 of the present application; Fig. 9 and Fig.10 is a schematic diagram of a resonant filter according to another modified example of Embodiment 1 of the present application; Fig.11 is a schematic diagram of a resonant filter according to another modified example of Embodiment 1 of the present application; Figure 12 to Figure 31 It is a structural schematic diagram corresponding to each step of the method for manufacturing a resonant filter according to Embodiment 2 of the present application; Figure 32~Figure 35 It is a structural schematic diagram corresponding to each step of the production method described in a modified example of Example 2 of the present application. DETAILED DESCRIPTION

[0020] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present disclosure may be combined with each other. The present disclosure will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0021] In order to enable those skilled in the art to better understand the scheme of the present disclosure, the technical scheme in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present disclosure.

[0022] It should be noted that the terms "first", "second", etc. in the specification and claims of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so as to describe the embodiments of the present disclosure described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0023] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof. Example 1

[0024] Figure 1 is a schematic diagram of the layer structure of the resonant filter according to Embodiment 1 of the present application; Figure 2 is a schematic top view of the resonant filter according to Embodiment 1 of the present application; Figure 3 This is a circuit diagram of the resonant filter according to Example 1 of the present application.

[0025] refer to Figure 1 As shown, the resonant filter according to this embodiment includes: a first substrate 210; and a resonant filter structure formed on a first side of the first substrate 210. Figure 1 In the embodiment, the first side of the first substrate 210 corresponds to the upper side of the first substrate 210, so that the resonant filter structure is formed on the upper side of the first substrate 210. However, the protection scope of the present invention is not limited thereto. Figure 1 When the device shown is flipped, the first side of the first substrate 210 may also correspond to the lower side of the first substrate 210. Similar situations in the present specific implementation will not be described in detail.

[0026] refer to Figure 1 and Figure 2 As shown, the resonant filter structure includes a bulk acoustic wave resonance structure BAWR and a Lamb wave resonance structure LWR, and the bulk acoustic wave resonance structure BAWR and the Lamb wave resonance structure LWR are electrically connected. The bulk acoustic wave resonance structure BAWR includes a first electrode structure 131, and the Lamb wave resonance structure LWR includes a second electrode structure 132. Figure 1As shown, the first electrode structure 131 corresponds to the upper electrode of the bulk acoustic wave resonance structure BAWR, and the second electrode structure 132 corresponds to the upper electrode of the Lamb wave resonance structure LWR, and the first electrode structure 131 and the second electrode structure 132 share the same first electrode layer 130 .

[0027] As described in the background technology, if the BAW resonator and the Lamb wave resonator can be combined, the resonant filter circuit formed can flexibly configure the stopband frequency of the resonant filter circuit on the basis of achieving excellent bandpass performance. At present, the BAW resonator and the Lamb wave resonator are both devices independently formed by their own processes, so the resonant filter circuit can only be constructed by combining the independently formed BAW resonator and the Lamb wave resonator. Since the BAW resonator and the Lamb wave resonator are both independent resonant filter devices, the integration of the resonant filter circuit is low.

[0028] In view of this, in the resonant filter described in this embodiment, the bulk acoustic wave resonant structure and the Lamb wave resonant structure share the same substrate, and the bulk acoustic wave resonant structure and the Lamb wave resonant structure also share the same electrode layer. In this way, this embodiment integrates the bulk acoustic wave resonant structure and the Lamb wave resonant structure into a resonant filter structure, and then integrates them into the same resonant filter device, thereby improving the integration of the resonant filter circuit.

[0029] In addition, as another aspect of this embodiment, reference Figure 1 As shown, the resonant filter structure includes a piezoelectric layer 140, and the bulk acoustic wave resonant structure BAWR and the Lamb wave resonant structure LWR share the piezoelectric layer 140. In this way, since the bulk acoustic wave resonant structure BAWR and the Lamb wave resonant structure LWR share the same piezoelectric layer 140, the integration of the resonant filter structure can also be improved.

[0030] Optionally, refer to Figure 2 As shown, the second electrode structure 132 includes interdigitated electrodes. Figure 1 As shown, the resonant filter structure includes a piezoelectric layer 140, and the bulk acoustic wave resonance structure BAWR and the Lamb wave resonance structure LWR share the piezoelectric layer 140. In addition, the first electrode structure 131 and the second electrode structure 132 are located on a first side of the piezoelectric layer 140, wherein the first side of the piezoelectric layer 140 is away from the first substrate 210. Figure 1 As shown, the first side of the piezoelectric layer 140 corresponds to the upper side of the piezoelectric layer 140, so that in this embodiment, the first electrode structure 131 and the second electrode structure 132 are located on the upper side of the piezoelectric layer 140. In this way, since the bulk acoustic wave resonance structure BAWR and the Lamb wave resonance structure LWR share the same piezoelectric layer 140, the integration of the resonance filter structure is further improved.

[0031] Optionally, refer to Figure 1 As shown, the bulk acoustic wave resonance structure BAWR further includes a third electrode structure 150a located on the second side (i.e., the lower side) of the piezoelectric layer 140, wherein the third electrode structure 150a corresponds to the first electrode structure 131. The Lamb wave resonance structure LWR further includes a fourth electrode structure 150b located on the second side of the piezoelectric layer 140, wherein the fourth electrode structure 150b corresponds to the second electrode structure 132. And wherein, the third electrode structure 150a and the fourth electrode structure 150b share the same second electrode layer 150.

[0032] In this way, the bulk acoustic wave resonance structure BAWR and the Lamb wave resonance structure LWR not only share the same first electrode layer, but also share the same second electrode layer, thereby further improving the integration of the resonance filter structure.

[0033] In addition, further reference Figure 1 As shown, the resonant filter structure further includes: a first resonant cavity 1801, wherein the first resonant cavity 1801 is formed between the bulk acoustic wave resonant structure BAWR and the first substrate 210; and a second resonant cavity 1802, wherein the second resonant cavity 1802 is formed between the Lamb wave resonant structure LWR and the first substrate 210.

[0034] Specifically, refer to Figure 1 As shown, a first support structure SUP1, a second support structure SUP2 and a third support structure SUP3 are formed on the first side of the first substrate 210. The first support structure SUP1 is used to support the piezoelectric layer 140, and the second support structure SUP2 and the third support structure SUP3 are used to support the second electrode layer 150. One end of the third electrode structure 150a is supported by the second support structure SUP2, and the other end is a free end. The fourth electrode structure 150b is jointly supported by the second support structure SUP2 and the third support structure SUP3. Thus, a first resonant cavity 1801 is formed between the first support structure SUP1 and the second support structure SUP2, and a second resonant cavity 1802 is formed between the second support structure SUP2 and the third support structure SUP3.

[0035] Thus, in this way, based on the integration of the BAW resonant structure and the Lamb wave resonant structure in the same resonant filter structure, the present embodiment respectively forms an electrode support structure and a resonant cavity suitable for the BAW resonant structure and the Lamb wave resonant structure according to the structural characteristics of the BAW resonant structure and the Lamb wave resonant structure. Thus, the BAW resonant structure and the Lamb wave resonant structure integrated in the same resonant filter structure can both work normally and exert the performance of different resonant structures.

[0036] Optionally, refer to Figure 1As shown, the resonant filter also includes: a second substrate 250, wherein the second substrate 250 includes a central area and an edge area, wherein the central area covers the bulk acoustic wave resonance structure BAWR and the Lamb wave resonance structure LWR; and a second bonding layer 240, the second bonding layer 240 corresponds to the edge area of ​​the first side of the second substrate 250, and is used to bond the second substrate 250 to the resonant filter structure.

[0037] So refer to Figure 1 As shown, a third resonant cavity 2400 is formed between the resonant filter structure and the second substrate 250. The third resonant cavity 2400 is shared by the bulk acoustic wave resonator structure BAWR and the Lamb wave resonator structure LWR.

[0038] Therefore, in this embodiment, on the one hand, the resonant filter structure is protected by the second substrate, and the second substrate and the bonding layer are used to form a resonant cavity shared by the bulk acoustic wave resonant structure and the Lamb wave resonant structure, thereby further improving the integration of the resonant filter.

[0039] refer to Figure 1 As shown, a conductive electrode electrically connected to the bulk acoustic wave resonance structure BAWR and the Lamb wave resonance structure LWR is disposed on the second side of the second substrate 250. Thus, the resonant filter structure of the resonant filter is electrically connected to the outside through the conductive electrode.

[0040] Furthermore, the conductive electrode includes a first conductive electrode 270a and a second conductive electrode 270b. The first conductive electrode 270a is electrically connected to the second electrode layer 150 via a through hole; and the second conductive electrode 270b is electrically connected to the first interdigital electrode 132b of the second electrode structure 132 via a through hole. Figure 3 As shown, through this type of electrical connection, a series structure between the bulk acoustic wave resonance structure BAWR and the Lamb wave resonance structure LWR is achieved.

[0041] also, Figure 4~Figure 6 A schematic diagram for describing a modified example of the resonant filter described in Embodiment 1. Figure 4 and Figure 5 As shown, in this modification, the conductive electrodes include a first conductive electrode 270a, a second conductive electrode 270b and a third conductive electrode 260a. The first conductive electrode 270a is electrically connected to the second electrode layer 150 via a through-hole conduction; the second conductive electrode 270b is electrically connected to the first interdigital electrode 132b of the second electrode structure 132 via a through-hole conduction; and the third conductive electrode 260a is electrically connected to the first electrode structure 131 and the second interdigital electrode 132a of the second electrode structure 132 via a through-hole conduction.

[0042] So refer to Figure 6As shown, through this type of electrical connection, a parallel structure between the bulk acoustic wave resonance structure BAWR and the Lamb wave resonance structure LWR is achieved.

[0043] also, Figure 7 and Figure 8 A schematic diagram for describing another modified example of the resonant filter described in Embodiment 1. Figure 7 and Figure 8 As shown, in this modification, the second side of the first substrate 210 is provided with a conductive electrode electrically connected to the bulk acoustic wave resonance structure BAWR and the Lamb wave resonance structure LWR. Figure 7 and Figure 8 In the embodiment, the resonant filter is turned upside down so that the second side of the first substrate 210 corresponds to the upper side of the first substrate 210 .

[0044] Thus, a through-hole conduction structure for connecting a conductive electrode and a bulk acoustic wave resonator structure BAWR and a through-hole conduction structure for connecting a conductive electrode and a bulk acoustic wave resonator structure LWR are formed on the first substrate 210. In addition to penetrating the bonding layer, they also sequentially penetrate the cutoff boundary layer, the sacrificial layer, the dielectric layer, the piezoelectric layer and other solid material layers. Since these layers are mainly composed of solid materials with high mechanical strength and toughness, the risk of fracture caused by weak material connection (such as the bonding layer) can be significantly reduced during perforation, and the local stress concentration that may be introduced by the perforation operation is reduced, which greatly reduces the fracture of the filter device caused by perforation during the manufacturing and use of the filter device, thereby improving the reliability and stability of the filter device.

[0045] Further optionally, reference Figure 7 As shown, the conductive electrode includes a fourth conductive electrode 270c and a fifth conductive electrode 270d. The fourth conductive electrode 270c is electrically connected to the second electrode layer 150 via a through hole; and the fifth conductive electrode 270d is electrically connected to the first interdigitated electrode 132b of the second electrode structure 132 via a through hole. Thus, through this electrical connection, a series structure between the bulk acoustic wave resonance structure BAWR and the Lamb wave resonance structure LWR is realized (refer to Figure 3 as shown).

[0046] Further optionally, reference Figure 8As shown, the conductive electrodes include a fourth conductive electrode 270c, a fifth conductive electrode 270d and a sixth conductive electrode 260b. The fourth conductive electrode 270c is electrically connected to the second electrode layer 150 via a through-hole conduction; the fifth conductive electrode 270d is electrically connected to the first interdigitated electrode 132b of the second electrode structure 132 via a through-hole conduction; and the sixth conductive electrode 260b is electrically connected to the second interdigitated electrode 132a of the first electrode structure 131 and the second electrode structure 132 via a through-hole conduction. Thus, through this type of electrical connection, a parallel structure between the bulk acoustic wave resonance structure BAWR and the Lamb wave resonance structure LWR is realized (refer to Figure 6 as shown).

[0047] In addition, reference Fig. 9 As shown, the resonant filter structure described in this embodiment includes multiple bulk acoustic wave resonant structures BAWR and multiple Lamb wave resonant structures LWR. Therefore, in this embodiment, not only a bulk acoustic wave resonant structure and a Lamb wave resonant structure are integrated into a resonant filter structure, but also multiple bulk acoustic wave resonant structures and multiple Lamb wave resonant structures can be integrated into a resonant filter structure. This further improves the integration of the resonant filter. In addition, referring to Fig.10 As shown, further optionally, a plurality of bulk acoustic wave resonance structures BAWR and a plurality of Lamb wave resonance structures LWR form a ladder filter structure.

[0048] In addition, further reference Fig.11 As shown, the Lamb wave resonance structure LWR can be a dual-mode filter structure. Thus, the second electrode structure 132 of the Lamb wave resonance structure LWR is Fig.11 The electrode structure shown.

[0049] In summary, in the resonant filter described in this embodiment, the bulk acoustic wave resonant structure and the Lamb wave resonant structure share the same substrate, and the bulk acoustic wave resonant structure and the Lamb wave resonant structure also share the same electrode layer or piezoelectric layer. In this way, this embodiment integrates the bulk acoustic wave resonant structure and the Lamb wave resonant structure into a resonant filter structure, and then integrates them into the same resonant filter device, thereby improving the integration of the resonant filter circuit. Example 2

[0050] also, Figure 12 to Figure 31 It is a schematic diagram of the layer structure in each manufacturing process of the resonant filter described in Example 2 of the present application.

[0051] Embodiment 2 provides a method for manufacturing a resonant filter. The resonant filter corresponds to the resonant filter described in Embodiment 1. Specifically, the method includes: manufacturing a first substrate used as a carrier and a resonant filter structure, wherein the resonant filter structure is formed on a first side of the first substrate, the resonant filter structure includes a bulk acoustic wave resonant structure and a Lamb wave resonant structure, and the bulk acoustic wave resonant structure and the Lamb wave resonant structure are electrically connected. And wherein the bulk acoustic wave resonant structure includes a first electrode structure, the Lamb wave resonant structure includes a second electrode structure, and the first electrode structure and the second electrode structure share the same first electrode layer; or, the bulk acoustic wave resonant structure and the Lamb wave resonant structure share the same piezoelectric layer.

[0052] Specifically, the method for manufacturing the resonant filter described in Embodiment 2 includes: like Fig.12 As shown, a transition layer 110, a seed layer 120, a first electrode layer 130, a piezoelectric layer 140 and a second electrode layer 150 are sequentially fabricated on a temporary substrate 100 used as a temporary substrate. Optionally, the temporary substrate 100 is a silicon substrate, a silicon substrate on an insulator, a glass substrate, a silicon carbide substrate or a gallium arsenide (GaAs) substrate, etc.; the transition layer 110 can be a silicon oxide (SiO2) layer or a silicon nitride (SiNx) layer, etc., and the formation method can be a thermal oxidation process, a physical vapor deposition (PVD) process or a chemical vapor deposition (CVD) process, etc.; the seed layer 120 can be an aluminum nitride (AlN) layer, and the formation method can be a physical vapor deposition (PVD) process, specifically a magnetron sputtering process; the first electrode layer 130 can be an Al layer, a Cu layer, a Mo layer, etc. layer, Au layer or Pt layer, which can be formed by physical vapor deposition (PVD) process; similarly, the second electrode layer 150 can be an Al layer, a Cu layer, a Mo layer, an Au layer or a Pt layer, which can be formed by physical vapor deposition (PVD) process; the piezoelectric layer 140 can be an AlN layer, a scandium-doped aluminum nitride (AlxSc1-xN) layer, a lithium niobate (LiNbO3) layer, a lithium tantalate (LiTaO3) layer or a quartz layer, etc., and can be a polycrystalline layer or a single crystal layer, and can be formed by PVD or metal organic chemical vapor deposition (MOCVD) etc.

[0053] like Fig.13 As shown, the first region of the second electrode layer 150 is etched to form a step structure 151 in the second electrode layer 150 to improve the performance of the resonant filter structure. Specifically, in one embodiment of the present application, the process of etching the second electrode layer 150 can be a dry etching process or a wet etching process, but the present application does not limit this, and it depends on the specific situation.

[0054] like Fig.14As shown, a dielectric layer 160 is formed on the side of the second electrode layer 150 away from the temporary substrate 100. Optionally, the dielectric layer 160 is formed by a deposition process, specifically PVD or CVD, etc. The material of the dielectric layer 160 can be SiO2, SiNx or AlN, etc., which is not limited in this application and depends on the specific situation. It should be noted that in the embodiment of the present application, the dielectric layer 160 is a protective layer of the second electrode layer 150 to prevent the second electrode layer 150 from being oxidized. Optionally, the dielectric layer 160 also serves as a dielectric layer of a capacitor formed subsequently.

[0055] like Fig.15 As shown, the second region of the second electrode layer 150 and the portion of the dielectric layer 160 located on the surface of the second region of the second electrode layer are etched to obtain the second electrode layer 150, the second electrode layer 150 includes the remaining portion of the second electrode layer 150 and the portion of the dielectric layer 160 located on the surface of the second electrode layer 150, and the second region is located on the first side of the step structure in a plane parallel to the temporary substrate 100. Optionally, the process of etching the dielectric layer 160 and the second electrode layer 150 may be a wet etching process or a dry etching process.

[0056] like Fig.16 As shown, a capacitor electrode 170 is formed in the third area on the surface of the dielectric layer 160, that is, the capacitor electrode 170 is formed in the third area on the surface of the dielectric layer 160 away from the piezoelectric layer 140. In a plane parallel to the temporary substrate 100, the third area is located on the second side of the step structure 151, and the second side is opposite to the first side. It should be noted that in this embodiment, the capacitor electrode 170, the dielectric layer 160, and the second electrode layer 150 form a capacitor. Optionally, the material of the capacitor electrode 170 can be Al, Cu, Mo, Au or Pt, etc., which is not limited in this application and depends on the specific situation.

[0057] like Fig.17 As shown, a sacrificial layer 180 is formed, and the sacrificial layer 180 covers the exposed part of the piezoelectric layer 140, the dielectric layer 160 and the capacitor electrode 170. Optionally, the material of the sacrificial layer 180 can be SiO2, PSG, USG, a-Si or photoresist, etc.; the formation process of the sacrificial layer 180 can be PVD, CVD or spin coating, etc.

[0058] like Fig.18 As shown, the sacrificial layer 180 is etched to form first through holes 181 to third through holes 183 in the sacrificial layer 180, wherein the first through hole 181 exposes a portion of the surface of the piezoelectric layer 140, and the second through hole 182 and the third through hole 183 expose a portion of the surface of the dielectric layer 160. Specifically, the etching process of the sacrificial layer 180 can be dry etching or wet etching.

[0059] like Fig.19 As shown, a cut-off boundary layer 190 is formed on the side of the sacrificial layer 180 away from the dielectric layer 160, and the cut-off boundary layer 190 also fills the first through hole 181 to the third through hole 183. It should be noted that, in this embodiment, the cut-off boundary layer portion corresponding to the first through hole 181 is in contact with the piezoelectric layer 140, and the cut-off boundary layer portion corresponding to the second through hole 182 and the third through hole 183 is in contact with the dielectric layer 160.

[0060] It should also be noted that, in this embodiment, the cut-off boundary layer 190 and the sacrificial layer 180 are made of different materials, so that the chemical substances used when etching the sacrificial layer 180 will not damage the cut-off boundary layer 190. Optionally, the cut-off boundary layer 190 may be made of SiO2 or polycrystalline silicon (poly-Si), and the formation process may be PVD, CVD, etc.

[0061] like Fig. 20 As shown, a first bonding layer 200 is formed on the side of the cut-off boundary layer 190 away from the piezoelectric layer 140, and the first bonding layer 200 covers the surface of the cut-off boundary layer 190 and also fills the first through hole 181 to the third through hole 183. Thus, the first bonding layer 200 and the cut-off boundary layer 190 corresponding to the first through hole 181 to the third through hole 183 form a first support structure SUP1, a second support structure SUP2 and a third support structure SUP3. Optionally, the material of the first bonding layer 200 can be SiO2, and the formation process can be PVD or CVD, etc., which is not limited in this application and depends on the specific situation.

[0062] like Fig.21 As shown, a first substrate 210 serving as a carrier is bonded to a side of the first bonding layer 200 away from the stop boundary layer 190 .

[0063] like Fig. 22 As shown, the wafer composed of the various structures obtained above is turned over to remove the temporary substrate 100 and the transition layer 110. Optionally, the removal process of the temporary substrate 100 and the transition layer 110 can be grinding or chemical mechanical polishing (CMP), which is not limited in the present application and depends on the specific circumstances.

[0064] like Fig.23 As shown, the seed layer 120 and the first electrode layer 130 are etched to form a first electrode structure 131 and a second electrode structure 132. The second electrode structure 132 includes an interdigitated electrode. Optionally, the etching process of the seed layer 120 and the first electrode layer 130 can be wet etching or dry etching. In addition, the seed layer 120 is also etched into a first seed layer portion 121 corresponding to the first electrode structure 131 and a second seed layer portion 122 corresponding to the second electrode structure 132.

[0065] like Fig.24 As shown, a fourth through hole 1401 is formed in the exposed portion of the piezoelectric layer 140 and a fifth through hole 1201 is formed in the seed layer 120, and the fourth through hole 1401 penetrates the piezoelectric layer 140, exposing a portion of the surface of the second electrode layer 150, so as to facilitate the extraction of the second electrode layer 150. The fifth through hole 1201 penetrates the seed layer 120 (for example, the second seed layer portion 122), exposing the second electrode structure 132 (for example, the first interdigitated electrode 132b). Optionally, the formation process of the fifth through hole 1201 and the fourth through hole 1401 can be a wet etching process or a dry etching process.

[0066] like Fig.25 As shown, a first conductive layer 230 is formed in the fifth through hole 1201, the first conductive layer 230 covers the side wall of the fifth through hole 1201 and the bottom of the fifth through hole 1201, and also extends to cover a portion of the surface of the seed layer 120; a second conductive layer 220 is formed in the fourth through hole 1401, the second conductive layer 220 covers the side wall of the fourth through hole 1401 and the bottom of the fourth through hole 1401, and also extends to cover a portion of the surface of the piezoelectric layer 140. Optionally, in an embodiment of the present application, the material of the second conductive layer 220 and the first conductive layer 230 may be Au, Cu, Al, etc., and the formation method may be PVD or electroplating, etc.

[0067] like Fig.26 As shown, the sacrificial layer 180 is released between the first support structure SUP1 and the second support structure SUP2 and between the second support structure SUP2 and the third support structure SUP3, forming a first resonant cavity 1801 between the first support structure SUP1 and the second support structure SUP2 and a second resonant cavity 1802 between the second support structure SUP2 and the third support structure SUP3. Thus, a resonant filter structure is formed, which includes a bulk acoustic wave resonant structure BAWR and a Lamb wave resonant structure LWR.

[0068] Thus, as described above, the method described in this embodiment includes manufacturing a first substrate 210 used as a carrier and a resonant filter structure, wherein the resonant filter structure is formed on the first side of the first substrate 210, and the resonant filter structure includes a bulk acoustic wave resonance structure BAWR and a Lamb wave resonance structure LWR, and the bulk acoustic wave resonance structure BAWR and the Lamb wave resonance structure LWR are electrically connected. And wherein the bulk acoustic wave resonance structure BAWR includes a first electrode structure 131, and the Lamb wave resonance structure LWR includes a second electrode structure 132, wherein the second electrode structure 132 includes an interdigitated electrode, and the first electrode structure 131 and the second electrode structure 132 share the same first electrode layer 130.

[0069] As described in the background technology, since the BAW resonator and the Lamb wave resonator are formed by their own processes, the process cost of constructing the resonant filter circuit is also very high. In view of this, the method for manufacturing the resonant filter described in this embodiment can simultaneously manufacture the BAW resonant structure and the Lamb wave resonant structure in the same set of processing steps, thereby reducing the process cost of constructing the resonant filter circuit.

[0070] Optionally, the second electrode structure 132 includes interdigitated electrodes. Figure 12 to Figure 26 The process of manufacturing the resonant filter structure includes: manufacturing a piezoelectric layer 140 shared by the bulk acoustic wave resonant structure BAWR and the Lamb wave resonant structure LWR, wherein the first side of the piezoelectric layer 140 is adjacent to the first electrode layer 130. Thus, the piezoelectric layers of the bulk acoustic wave resonant structure BAWR and the Lamb wave resonant structure LWR can be formed simultaneously in the same process, thereby reducing the process cost of constructing the resonant filter circuit.

[0071] Alternatively, refer to Figure 12 to Figure 26 The process of manufacturing the resonant filter structure also includes: manufacturing a second electrode layer 150 on the second side of the piezoelectric layer 140; and using the second electrode layer 150 to form a third electrode structure 150a of a bulk acoustic wave resonance structure and a fourth electrode structure 150b of a Lamb wave resonance structure, wherein the third electrode structure 150a corresponds to the first electrode structure 131, and the fourth electrode structure 150b corresponds to the second electrode structure 132. Thus, the third electrode structure 150a of the bulk acoustic wave resonance structure BAWR and the fourth electrode structure 150b of the Lamb wave resonance structure LWR can be formed simultaneously in the same process, thereby reducing the process cost of constructing the resonant filter circuit.

[0072] In addition, reference Fig.26 The process of manufacturing the resonant filter structure also includes: forming a first resonant cavity 1801 between the bulk acoustic wave resonant structure BAWR and the first substrate 210, and forming a second resonant cavity 1802 between the Lamb wave resonant structure LWR and the first substrate 210. Thus, the first resonant cavity 1801 of the bulk acoustic wave resonant structure BAWR and the second resonant cavity 1802 of the Lamb wave resonant structure LWR can be formed simultaneously in the same process, thereby reducing the process cost of constructing the resonant filter circuit.

[0073] Optionally, the method further comprises: bonding the second substrate to the resonant filter structure using a bonding layer, wherein the second substrate comprises a central region and an edge region, wherein the central region covers the bulk acoustic wave resonant structure and the Lamb wave resonant structure; and the bonding layer corresponds to the edge region of the first side of the second substrate.

[0074] Specifically, Fig. 27As shown, the method includes forming a second bonding layer 240, which is located on a side of the first electrode layer 130 away from the piezoelectric layer 140, that is, the second bonding layer 240 is located on a side of the seed layer 120 away from the piezoelectric layer 140, and the second bonding layer 240 also covers the exposed surface of the piezoelectric layer 140.

[0075] Optionally, the material of the second bonding layer 240 is SiO2 or SiNx, etc., and the formation process can be PVD or CVD, etc.; in another embodiment of the present application, the second bonding layer 240 is a photoresist-like dry film material, which is formed by spin coating, photolithography and other processes. The present application does not limit this, and it depends on the specific situation.

[0076] Furthermore, if Fig.28 As shown, the second bonding layer 240 is etched to form a space in the central area for constructing the third resonant cavity 2400 .

[0077] Then as Fig.29 As shown, a second substrate 250 is bonded on the second bonding layer 240. Thus, the central area of ​​the second substrate 250 covers the bulk acoustic wave resonance structure BAWR and the Lamb wave resonance structure LWR, and the second bonding layer 240 corresponds to the edge area of ​​the first side of the second substrate 250. Thus, a third resonant cavity 2400 is also formed between the resonant filter structure and the second substrate 250. And the bulk acoustic wave resonance structure BAWR and the Lamb wave resonance structure LWR share the third resonant cavity 2400. Therefore, on the one hand, this embodiment protects the resonant filter structure through the second substrate, and forms a resonant cavity shared by the bulk acoustic wave resonance structure and the Lamb wave resonance structure in the same process, thereby further reducing the process cost of constructing the resonant filter circuit.

[0078] Optionally, the method further comprises forming a conductive electrode on the second side of the second substrate electrically connected to the BAW resonance structure and the Lamb wave resonance structure.

[0079] Specifically, Fig.30 As shown, a sixth through hole 2501 and a seventh through hole 2502 are formed penetrating the second substrate 250 and the second bonding layer 240 , wherein the sixth through hole 2501 exposes the first conductive layer 230 , and the seventh through hole 2502 exposes the second conductive layer 220 .

[0080] Then, if Fig.31As shown, a first conductive electrode 270a and a second conductive electrode 270b electrically connected to the second conductive layer 220 and the first conductive layer 230 are formed on the second side of the second substrate 250. Thus, the first conductive electrode 270a and the second conductive electrode 270b are electrically connected to the bulk acoustic wave resonance structure BAWR and the Lamb wave resonance structure LWR. Optionally, the material of the second conductive layer 220 and the first conductive layer 230 can be Au, Cu or Al, etc., and the formation method can be PVD or electroplating, etc.

[0081] Alternatively, if Fig.31 As shown, the process of forming a conductive electrode electrically connected to the bulk acoustic wave resonance structure BAWR and the Lamb wave resonance structure LWR on the second side of the second substrate 250 also includes: forming a first conductive electrode 270a and a second conductive electrode 270b on the second side of the second substrate 250. The first conductive electrode 270a is electrically connected to the second electrode layer 150 via a through-hole conduction, and the second conductive electrode is electrically connected to the first interdigital electrode 132b of the second electrode structure via a through-hole conduction. In this way, a series structure between the bulk acoustic wave resonance structure BAWR and the Lamb wave resonance structure LWR is realized.

[0082] In addition, according to a modified example of the present embodiment, the process of forming a conductive electrode electrically connected to the bulk acoustic wave resonance structure BAWR and the Lamb wave resonance structure LWR on the second side of the second substrate 250 also includes: forming a first conductive electrode 270a, a second conductive electrode 270b and a third conductive electrode 260a on the second side of the second substrate 250. And wherein, the first conductive electrode 270a is electrically connected to the second electrode layer 150 via a through-hole conduction, the second conductive electrode 270b is electrically connected to the first interdigital electrode 132b of the second electrode structure 132 via a through-hole conduction, and the third conductive electrode 260a is electrically connected to the second interdigital electrode 132a of the first electrode structure 131 and the second electrode structure 132 via a through-hole conduction. The resonant filter formed specifically is as follows. Figure 4 and Figure 5 The specific formation process can be Figure 24~Figure 31 Based on the process shown, the third conductive electrode 260a and the corresponding through hole and the conductive layer can be adjusted, which will not be repeated here. In this way, the parallel structure between the bulk acoustic wave resonance structure BAWR and the Lamb wave resonance structure LWR is realized.

[0083] In addition, according to a modification of the present embodiment, the method further includes forming a conductive electrode electrically connected to the bulk acoustic wave resonance structure BAWR and the Lamb wave resonance structure LWR on the second side of the first substrate 210 .

[0084] Specifically refer to Figures 32 to 35 As shown. Fig.321 is a schematic diagram of the layer structure after bonding the second substrate 250 according to the modified example, wherein the second electrode layer 150 is also partially etched in the edge region, and the etched region is covered by the sacrificial layer 180 to form a through hole and a conductive electrode.

[0085] Then refer to Fig.33 As shown, the resonator filter is turned upside down so that the first substrate 210 is located on the upper side of the device.

[0086] Then refer to Fig.34 As shown, the eighth through hole 2101 to the tenth through hole 2103 are formed from the first substrate 210. The eighth through hole 2101 penetrates the first substrate 210, the first bonding layer 200, the cut-off boundary layer 190, the sacrificial layer 180 and the piezoelectric layer 140, thereby exposing the first electrode structure 131. The ninth through hole 2102 penetrates the first substrate 210, the first bonding layer 200, the cut-off boundary layer 190, the sacrificial layer 180 and the dielectric layer 160, thereby exposing the second electrode layer 150. The tenth through hole 2103 penetrates the first substrate 210, the first bonding layer 200, the cut-off boundary layer 190, the sacrificial layer 180 and the piezoelectric layer 140, thereby exposing the first interdigitated electrode 132b of the second electrode structure.

[0087] Then, refer to Fig.35 As shown, a sixth conductive electrode 260b, a fourth conductive electrode 270c and a fifth conductive electrode 270d are formed on the second side of the first substrate 210, so as to be electrically connected to the bulk acoustic wave resonance structure BAWR and the Lamb wave resonance structure LWR through via conduction.

[0088] Thus, a through-hole conduction structure for connecting the conductive electrode and the bulk acoustic wave resonance structure BAWR and a through-hole conduction structure for connecting the conductive electrode and the bulk acoustic wave resonance structure LWR are formed on the first substrate 210, and sequentially penetrate the cutoff boundary layer, the sacrificial layer, the dielectric layer, the piezoelectric layer and other solid material layers. Since these layers are mainly composed of solid materials with high mechanical strength and toughness, the risk of fracture caused by weak connection of the material (such as the bonding layer) can be significantly reduced during perforation, and the local stress concentration that may be introduced by the perforation operation is reduced, which greatly reduces the fracture of the filter device caused by perforation during the manufacturing and use of the filter device, and improves the reliability and stability of the filter device.

[0089] Optionally, refer to Fig.34 and Fig.35As shown, the process of forming a conductive electrode electrically connected to the bulk acoustic wave resonance structure BAWR and the Lamb wave resonance structure LWR on the second side of the first substrate 210 includes forming a fourth conductive electrode 270c, a fifth conductive electrode 270d and a sixth conductive electrode 260b on the second side of the first substrate 210. And wherein, the fourth conductive electrode 270c is electrically connected to the second electrode layer 150 via a through-hole conduction; the fifth conductive electrode 270d is electrically connected to the first interdigital electrode 132b of the second electrode structure 132 via a through-hole conduction; and the sixth conductive electrode 260b is electrically connected to the first electrode structure 131 and the second electrode structure 132 via a through-hole conduction. Thus, through this type of electrical connection, a parallel structure between the bulk acoustic wave resonance structure BAWR and the Lamb wave resonance structure LWR is realized (refer to Figure 6 as shown).

[0090] Alternatively, if Figure 7 As shown, the process of forming a conductive electrode electrically connected to the bulk acoustic wave resonance structure BAWR and the Lamb wave resonance structure LWR on the second side of the first substrate 210 includes forming a fourth conductive electrode 270c and a fifth conductive electrode 270d on the second side of the first substrate 210. And wherein, the fourth conductive electrode 270c is electrically connected to the second electrode layer 150 via a through hole conduction; and the fifth conductive electrode 270d is electrically connected to the first interdigital electrode 132b of the second electrode structure 132 via a through hole conduction. Thus, through this type of electrical connection, a series structure between the bulk acoustic wave resonance structure BAWR and the Lamb wave resonance structure LWR is realized (refer to Figure 3 as shown).

[0091] The method for manufacturing the resonant filter described in this embodiment can simultaneously manufacture a bulk acoustic wave resonant structure and a Lamb wave resonant structure in the same set of processing steps, thereby reducing the process cost of constructing a resonant filter circuit.

[0092] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present disclosure. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0093] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" may include both "above" and "below". The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0094] In the description of the present disclosure, it is necessary to understand that the orientation or positional relationship indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present disclosure and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present disclosure; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0095] The above is only a preferred specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A resonant filter, characterized in that: include: A first substrate (210); as well as, A resonant filter structure is formed on the first side of the first substrate (210), wherein the resonant filter structure comprises a bulk acoustic wave resonant structure (BAWR) and a Lamb wave resonant structure (LWR), and the bulk acoustic wave resonant structure (BAWR) and the Lamb wave resonant structure (LWR) are electrically connected, wherein: The bulk acoustic wave resonance structure (BAWR) comprises a first electrode structure (131), and the Lamb wave resonance structure (LWR) comprises a second electrode structure (132), wherein the first electrode structure (131) and the second electrode structure (132) share the same first electrode layer (130); or, the bulk acoustic wave resonance structure (BAWR) and the Lamb wave resonance structure (LWR) share the same piezoelectric layer (140).

2. The resonant filter according to claim 1, characterized in that The second electrode structure (132) comprises an interdigitated electrode, and the first electrode structure (131) and the second electrode structure (132) are located on a first side of the piezoelectric layer (140), wherein the first side of the piezoelectric layer (140) is opposite to the first substrate (210).

3. The resonant filter according to claim 2, characterized in that The bulk acoustic wave resonance structure (BAWR) further comprises a third electrode structure (150a) located on the second side of the piezoelectric layer (140), wherein the third electrode structure (150a) corresponds to the first electrode structure (131); The Lamb wave resonance structure (LWR) further comprises a fourth electrode structure (150b) located on a second side of the piezoelectric layer (140), wherein the fourth electrode structure (150b) corresponds to the second electrode structure (132), and wherein: The third electrode structure (150a) and the fourth electrode structure (150b) share the same second electrode layer (150).

4. The resonant filter according to claim 2, characterized in that The resonant filter structure also includes: a first resonant cavity (1801), wherein the first resonant cavity (1801) is formed between the bulk acoustic wave resonator structure (BAWR) and the first substrate (210); and A second resonant cavity (1802), wherein the second resonant cavity (1802) is formed between the Lamb wave resonant structure (LWR) and the first substrate (210).

5. The resonant filter according to claim 3, characterized in that Also includes: a second substrate (250), wherein the second substrate (250) comprises a central region and an edge region, wherein the central region covers the bulk acoustic wave resonance structure (BAWR) and the Lamb wave resonance structure (LWR); and, A bonding layer, the bonding layer corresponding to an edge region of the first side of the second substrate (250), and used for bonding the second substrate (250) to the resonant filtering structure.

6. The resonant filter according to claim 5, characterized in that A conductive electrode electrically connected to the bulk acoustic wave resonance structure (BAWR) and the Lamb wave resonance structure (LWR) is provided on the second side of the second substrate (250).

7. The resonant filter according to claim 6, characterized in that The conductive electrodes include a first conductive electrode (270a) and a second conductive electrode (270b), and wherein, The first conductive electrode (270a) is electrically connected to the second electrode layer (150) via a through hole; and The second conductive electrode (270b) is electrically connected to the first interdigitated electrode (132b) of the second electrode structure (132) via a through hole.

8. The resonant filter according to claim 7, characterized in that The conductive electrodes include a first conductive electrode (270a), a second conductive electrode (270b) and a third conductive electrode (260a), and wherein, The first conductive electrode (270a) is electrically connected to the second electrode layer (150) via a through hole; The second conductive electrode (270b) is electrically connected to the first interdigitated electrode (132b) of the second electrode structure (132) via a through hole; and The third conductive electrode (260a) is electrically connected to the first electrode structure (131) and the second interdigitated electrodes (132a) of the second electrode structure (132) via a through hole.

9. The resonant filter according to claim 5, characterized in that A conductive electrode electrically connected to the bulk acoustic wave resonance structure (BAWR) and the Lamb wave resonance structure (LWR) is provided on the second side of the first substrate (210).

10. The resonant filter according to claim 9, characterized in that The conductive electrodes include a fourth conductive electrode (270c) and a fifth conductive electrode (270d), and wherein, The fourth conductive electrode (270c) is electrically connected to the second electrode layer (150) via a through hole; and The fifth conductive electrode (270d) is electrically connected to the first interdigitated electrode (132b) of the second electrode structure (132) via a through hole.

11. The resonant filter according to claim 9, characterized in that The conductive electrodes include a fourth conductive electrode (270c), a fifth conductive electrode (270d) and a sixth conductive electrode (260b), and wherein, The fourth conductive electrode (270c) is electrically connected to the second electrode layer (150) via a through hole; The fifth conductive electrode (270d) is electrically connected to the first interdigitated electrode (132b) of the second electrode structure (132) via a through hole; and The sixth conductive electrode (260b) is electrically connected to the first electrode structure (131) and the second interdigitated electrodes (132a) of the second electrode structure (132) via a through hole.

12. The resonant filter according to claim 1, characterized in that The resonant filter structure includes a plurality of the bulk acoustic wave resonant structures (BAWR) and a plurality of the Lamb wave resonant structures (LWR), and wherein, A plurality of said bulk acoustic wave resonator structures (BAWR) and a plurality of said Lamb wave resonator structures (LWR) constitute a ladder filter structure, and wherein, The Lamb wave resonance structure (LWR) is a dual-mode filter structure.

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