Bulk acoustic wave resonator assembly with acoustic decoupling layer, filter and electronic device

Abstract

The present application relates to a bulk acoustic wave resonator assembly, comprising: a substrate; at least two resonators, the at least two resonators being bulk acoustic wave resonators and stacked in a thickness direction of the substrate on one side of the substrate, the at least two resonators comprising a first resonator and a second resonator, the second resonator being above the first resonator, the first resonator having a first top electrode, a first piezoelectric layer, a first bottom electrode and a first acoustic mirror, the second resonator having a second top electrode, a second piezoelectric layer, a second bottom electrode and a second acoustic mirror. An acoustic decoupling layer in the form of a cavity is provided between the first top electrode and the second bottom electrode, the acoustic decoupling layer acting as the second acoustic mirror; a boundary of the cavity is outside a non-electrode-connection end of the first bottom electrode in a horizontal direction; and a boundary of the cavity is outside a non-electrode-connection end of the second top electrode in the horizontal direction. The present application also relates to a filter and an electronic device.

Description

Technical Field

[0001] Embodiments of the present invention relate to the semiconductor field, and more particularly to a bulk acoustic wave resonator assembly, a filter having the resonator assembly, and an electronic device. Background Technology

[0002] With the rapid development of wireless communication technology, the application of miniaturized portable terminal devices is becoming increasingly widespread, leading to a growing demand for high-performance, small-size radio frequency front-end modules and devices. In recent years, filter devices such as filters and duplexers based on thin-film acoustic resonators (FBARs) have become increasingly popular in the market. This is due to their excellent electrical performance, including low insertion loss, steep transition characteristics, high selectivity, high power capacity, and strong electrostatic discharge (ESD) resistance; and also to their small size and ease of integration.

[0003] However, in reality, there is a need to further reduce the size of filtering devices.

[0004] Furthermore, in existing designs, bulk acoustic wave resonators are combined in series and parallel to form filters. This requires multiple resonators to be formed on a substrate, with each resonator located at a different horizontal position on the substrate and connected by horizontal metal leads, such as... Figure 1 As shown, the dotted box indicates that the top electrode 104 of the resonator 100 is connected to the bottom electrode 102 of the resonator 200 through a conductive via 10. To ensure signal transmission and meet manufacturing process limitations, the connection width between the conductive via 10 and the top electrode 104 of the resonator 100, the width of the conductive via 10, the width of the top electrode 104 of the resonator 100, and the width of the bottom electrode 102 of the resonator 200 all have certain requirements. Generally, the total length is >5μm. This leads to the introduction of large electrical losses by the connection line, especially for high-frequency resonators. When the electrode thickness is <1000A, the insertion loss will deteriorate by more than 0.1dB. Summary of the Invention

[0005] The present invention is proposed to alleviate or solve at least one of the above-mentioned problems in the prior art.

[0006] According to one aspect of an embodiment of the present invention, a bulk acoustic resonator assembly is provided, comprising:

[0007] Base;

[0008] At least two resonators, which are bulk acoustic wave resonators, are stacked on one side of a substrate in the thickness direction of the substrate. The at least two resonators include a first resonator and a second resonator, with the second resonator above the first resonator. The first resonator has a first top electrode, a first piezoelectric layer, a first bottom electrode, and a first acoustic mirror. The second resonator has a second top electrode, a second piezoelectric layer, a second bottom electrode, and a second acoustic mirror.

[0009] in:

[0010] An acoustic decoupling layer in the form of a cavity is provided between the first top electrode and the second bottom electrode, and the acoustic decoupling layer serves as the second acoustic mirror;

[0011] The boundary of the cavity is located outside the non-electrode connection end of the first bottom electrode in the horizontal direction; and

[0012] The boundary of the cavity is located outside the non-electrode connection end of the second top electrode in the horizontal direction.

[0013] Embodiments of the present invention also relate to a bulk acoustic resonator assembly, comprising:

[0014] At least two resonators are stacked adjacent to each other from bottom to top in the thickness direction of the component. The at least two resonators are bulk acoustic wave resonators, and the at least two resonators include a first resonator and a second resonator.

[0015] in:

[0016] An acoustic decoupling layer in the form of a cavity is provided between the top electrode of the first resonator and the bottom electrode of the second resonator, and the acoustic decoupling layer serves as an acoustic mirror of the second resonator.

[0017] The boundary of the cavity is located horizontally outside the non-electrode connection end of the bottom electrode of the first resonator; and

[0018] The boundary of the cavity is located outside the non-electrode connection end of the top electrode of the second resonator in the horizontal direction.

[0019] Embodiments of the present invention also relate to a filter, including the aforementioned bulk acoustic resonator assembly.

[0020] Embodiments of the present invention also relate to an electronic device, including the filter or the resonator assembly described above. Attached Figure Description

[0021] The following description and accompanying drawings will better aid in understanding these and other features and advantages of the various embodiments disclosed herein, wherein the same reference numerals in the drawings always denote the same parts, wherein:

[0022] Figure 1A schematic cross-sectional view of the electrical connection between two adjacent bulk acoustic resonators in an existing design;

[0023] Figure 2 A schematic top view of a bulk acoustic resonator assembly according to an exemplary embodiment of the present invention;

[0024] Figure 3A For an exemplary embodiment of the present invention, along Figure 2 A schematic cross-sectional view of a bulk acoustic resonator intercepted by line A-A' in the diagram;

[0025] Figure 3B For an exemplary embodiment of the present invention, along Figure 2 A schematic cross-sectional view of a bulk acoustic resonator intercepted by the B-B' line;

[0026] Figure 3C For an exemplary embodiment of the present invention, along Figure 2 A schematic cross-sectional view of a bulk acoustic resonator intercepted by the C-C' line;

[0027] Figure 3D For illustrative purposes only Figure 3A The structure relative to Figure 1 A comparison of insertion loss curves for the structures;

[0028] Figure 4 This is a schematic top view of a bulk acoustic resonator assembly according to another exemplary embodiment of the present invention, showing only the acoustic mirror of the lower resonator, the bottom electrode and the top electrode of the lower resonator, the external leads of the electrodes of the lower resonator, and the external leads of the bottom electrode of the upper resonator.

[0029] Figure 5A For an exemplary embodiment of the present invention, along Figure 4 A schematic cross-sectional view of a bulk acoustic resonator intercepted by line A-A' in the diagram;

[0030] Figure 5B For an exemplary embodiment of the present invention, along Figure 4 A schematic cross-sectional view of a bulk acoustic resonator intercepted by the B-B' line;

[0031] Figure 5C For an exemplary embodiment of the present invention, along Figure 4 A schematic cross-sectional view of a bulk acoustic resonator intercepted by the C-C' line;

[0032] Figure 5D For an exemplary embodiment of the present invention, similar to along Figure 4 A schematic cross-sectional view of a bulk acoustic resonator intercepted by the C-C' line;

[0033] Figure 6 This is a schematic top view of a bulk acoustic resonator assembly according to another exemplary embodiment of the present invention, which mainly shows the positional relationship between the bottom electrode of the upper resonator and the cavity, as well as the external leads of the top electrode of the lower resonator and the bottom electrode of the upper resonator.

[0034] Figure 7A For an exemplary embodiment of the present invention, along Figure 6 A schematic cross-sectional view of a bulk acoustic resonator intercepted by line A-A' in the diagram;

[0035] Figure 7B For an exemplary embodiment of the present invention, along Figure 6 A schematic cross-sectional view of a bulk acoustic resonator intercepted by the B-B' line;

[0036] Figure 7C For an exemplary embodiment of the present invention, along Figure 6 A schematic cross-sectional view of a bulk acoustic resonator intercepted by the C-C' line;

[0037] Figure 7D For an exemplary embodiment of the present invention, similar to along Figure 6 A schematic cross-sectional view of a bulk acoustic resonator intercepted by the C-C' line;

[0038] Figure 8 A schematic cross-sectional view of a bulk acoustic resonator assembly according to an exemplary embodiment of the present invention;

[0039] Figure 9 This is a cross-sectional view of a resonator assembly according to an exemplary embodiment of the present invention, wherein the effective regions of the upper and lower resonators are acoustically isolated by cavities, and Figure 9 In the left-hand view, the upper and lower resonators are electrically isolated from each other. Figure 9 In the right-side view, the upper and lower resonators are electrically connected to each other. Detailed Implementation

[0040] The technical solution of the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. In this specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the overall inventive concept of the present invention and should not be construed as a limitation thereof. These are only some embodiments of the invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0041] The reference numerals in the drawings of this invention are explained as follows:

[0042] 11: The bottom electrode of the lower resonator has external leads.

[0043] 12: The top electrode of the lower resonator has external leads.

[0044] 13: The bottom electrode of the upper resonator has external leads.

[0045] 14: External leads of the top electrode of the upper resonator. The external leads 11-14 of the above electrodes are connected to the corresponding electrodes.

[0046] S: Substrate, with optional materials including single-crystal silicon, gallium nitride, gallium arsenide, sapphire, quartz, silicon carbide, diamond, etc.

[0047] 101, 201: Acoustic mirrors. Acoustic mirror 101 can be a cavity, or it can be a Bragg reflector layer or other equivalent forms. Acoustic mirror 201 is a cavity, which constitutes an acoustic decoupling layer.

[0048] 102,202: Bottom electrode, materials can be selected from molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium or composites or alloys of the above metals, etc.

[0049] 103, 203: Piezoelectric layer, which can be a single-crystal piezoelectric material, such as single-crystal aluminum nitride, single-crystal gallium nitride, single-crystal lithium niobate, single-crystal lead zirconate titanate (PZT), single-crystal potassium niobate, single-crystal quartz film, or single-crystal lithium tantalate, etc. It can also be a polycrystalline piezoelectric material (as opposed to single-crystal, a non-single-crystal material), such as polycrystalline aluminum nitride, zinc oxide, PZT, etc. It can also be a rare earth element containing a certain atomic ratio of the above materials. The doped material can be, for example, doped aluminum nitride, which contains at least one rare earth element, such as scandium (Sc), yttrium (Y), magnesium (Mg), titanium (Ti), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), etc.

[0050] 104, 204: Top electrode, whose material can be the same as the bottom electrode. Materials can include molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium, or composites or alloys of the above metals. The top and bottom electrodes are generally made of the same material, but they can also be different.

[0051] 105, 205: Passivation layer, generally a dielectric material, such as silicon dioxide, aluminum nitride, silicon nitride, etc.

[0052] 106,206: Disconnected structure.

[0053] Figure 2 This is a schematic top view of a bulk acoustic resonator assembly according to an exemplary embodiment of the present invention. Figure 2In the diagram, line A-A' corresponds to the cross-section through the non-electrode connection terminals of the top and bottom electrodes of the upper and lower resonators, line B-B' corresponds to the cross-section through the electrode connection terminals of the bottom and top electrodes of the lower resonator, and line C-C' corresponds to the cross-section through the electrode connection terminals of the bottom and top electrodes of the upper resonator.

[0054] Figure 3A For an exemplary embodiment of the present invention, along Figure 2 A schematic cross-sectional view of a bulk acoustic resonator obtained by the A-A' line.

[0055] Although not shown, a process layer can also be disposed on the top electrode of the resonator. This process layer can cover the top electrode and can function as a mass conditioning load or a passivation layer. The passivation layer can be made of a dielectric material, such as silicon dioxide, aluminum nitride, or silicon nitride.

[0056] In addition, Figure 3A In the structure shown, two resonators are formed at the same horizontal position on the substrate S, and the two resonators are spatially different in the vertical direction or in the thickness direction of the substrate.

[0057] As those skilled in the art will understand, three or more resonators may be stacked. Figure 8 This is a schematic cross-sectional view of a bulk acoustic resonator assembly according to an exemplary embodiment of the present invention. Figure 8 As shown, the resonator assembly includes a first resonator, a second resonator, and a third resonator stacked in the thickness direction. An acoustic mirror 201 (a cavity in this embodiment) is provided between the top electrode 104 of the first resonator and the bottom electrode 202 of the second resonator. An acoustic decoupling layer 301 (a cavity in this embodiment) is provided between the top electrode 204 of the second resonator and the bottom electrode 302 of the third resonator. The acoustic decoupling layer 301 constitutes the acoustic mirror of the third resonator. Optionally, such as... Figure 8 As shown, the boundary of the acoustic decoupling layer 301 is located outside the boundary of the acoustic mirror 201 in the horizontal direction. It will be understood that the component structures shown in other embodiments of the invention may also be superimposed.

[0058] exist Figure 3A The structure shown includes two resonators, an upper and a lower one. The effective region of the upper resonator is the overlapping area in the thickness direction of the top electrode 204, the piezoelectric layer 203, the bottom electrode 202, and the acoustic mirror 201. The lower resonator is the overlapping area in the thickness direction of the acoustic mirror 201, the top electrode 104, the piezoelectric layer 103, the bottom electrode 102, and the acoustic mirror 101.

[0059] Correspondingly, in Figure 8In the middle, the effective area of ​​the uppermost third resonator is the overlapping area of ​​the top electrode 304, piezoelectric layer 303, bottom electrode 302, and acoustic decoupling layer 301 in the thickness direction; the effective area of ​​the middle second resonator is the overlapping area of ​​the acoustic decoupling layer 301, top electrode 204, piezoelectric layer 203, bottom electrode 202, and acoustic mirror 201 in the thickness direction; and the effective area of ​​the lowermost first resonator is the overlapping area of ​​the acoustic mirror 201, top electrode 104, piezoelectric layer 103, bottom electrode 102, and acoustic mirror 101 in the thickness direction.

[0060] exist Figure 3A In the structure shown, the upper resonator and the lower resonator are acoustically separated by an acoustic mirror 201. That is, the acoustic mirror 201 constitutes an acoustic decoupling layer between the upper and lower resonators, thereby completely avoiding the acoustic coupling problem that may be caused by the adjacent stacking of the two resonators.

[0061] Using an acoustic mirror 201 as an acoustic decoupling layer enables complete acoustic decoupling of the upper and lower resonators, resulting in superior resonator performance. Furthermore, the acoustic mirror 201 is directly surrounded by the top electrode 104 of the lower resonator and the bottom electrode 202 of the upper resonator (in other embodiments, the structure defining the cavity location also includes the piezoelectric layer of the upper and / or lower resonator), for example... Figures 3A-3C The structure shown is stable and reliable, and the processing technology is simple.

[0062] As those skilled in the art will understand, the acoustic mirror 201 being disposed between the bottom electrode of the upper resonator and the top electrode of the lower resonator in the thickness direction of the resonator includes not only cases where at least a portion of the upper and lower boundaries of the cavity are defined by the lower surface of the bottom electrode of the upper resonator and the upper surface of the top electrode of the lower resonator, but also cases where a process layer (e.g., a passivation layer) is disposed on the upper surface of the top electrode of the lower resonator, thereby defining at least a portion of the lower boundary of the acoustic mirror 201. All of these are within the scope of protection of this invention.

[0063] exist Figure 3A In the structure shown, because multiple resonators are formed at the same horizontal position on the substrate S, and the spatial positions of these resonators differ in the vertical direction or in the thickness direction of the substrate, the area of ​​the filter can be greatly reduced. For example, with the same arrangement of two resonators, the area can be reduced from... Figure 1 The area P1 shown is reduced to Figure 3A The area P2 shown is shown.

[0064] like Figure 3AAs shown, the bottom electrode 202 of the upper resonator and the top electrode 104 of the lower resonator are electrically connected to each other at the non-electrode connection terminals. When the bottom electrode of the upper resonator is directly connected to the top electrode of the lower resonator, the bottom electrode of the upper resonator and the top electrode of the lower resonator are directly electrically connected, and the length of the connection portion is relatively... Figure 1 The intermediate frequency is shortened, meaning the transmission path is shortened, reducing transmission loss. Furthermore, the electrical signal output passes through a metal with a thickness equal to the sum of the thicknesses of the top electrode of the lower resonator and the bottom electrode of the upper resonator, further reducing transmission loss. By reducing electrical loss, the insertion loss of the final filter is optimized. For example... Figure 3A As shown, the length of the transmission path formed by the bottom electrode of the upper resonator and the top electrode of the lower resonator at the non-connected electrode end is d0, which can be less than 5μm.

[0065] Using the structure shown in Figures 3A-3C, the current transmission path to the lower resonator is shortened, for example, to less than 5 μm, reducing transmission loss. This allows for thinner top electrode 104 of the lower resonator and bottom electrode 202 of the upper resonator, facilitating further miniaturization of the resonator. With the bottom electrode of the upper resonator and the top electrode of the lower resonator electrically connected, the circuit transmission path loss to the bottom electrode of the upper resonator and the current transmission path loss to the top electrode of the lower resonator can be reduced, while simultaneously decreasing the electrode film thickness of both the bottom and top electrodes of the upper resonator. Correspondingly, when the resonant frequency of the lower resonator is greater than 0.5 GHz, the thickness of the top electrode 104 is less than... And / or, when the resonant frequency of the upper resonator is greater than 0.5 GHz, the thickness of the bottom electrode 202 is less than In a further embodiment, when the resonant frequency of the lower resonator is greater than 3 GHz, the thickness of the top electrode 104 can be designed to be less than [the required thickness]. And / or, when the resonant frequency of the upper resonator is greater than 3 GHz, the thickness of the bottom electrode 202 of the upper resonator can also be less than [a certain value]. As will be understood, in this invention, the thinning of the electrode thickness refers to the thinning of the portion of the electrode within the effective region of the resonator.

[0066] Figure 3D For illustrative purposes only Figure 3A The structure relative to Figure 1 A comparison of insertion loss curves for the structures. Figure 3D This invention is used in the 3.5G frequency band. Figure 3A The insertion loss curve (solid line) after the structure is compared with that after using Figure 1 A comparison of the insertion loss curve (dashed line) of the traditional structure shows that the method using the present invention... Figure 3A After the structure is completed, the insertion loss is improved by approximately 0.1 dB due to the reduction in electrode loss.

[0067] Figure 3B For an exemplary embodiment of the present invention, along Figure 2 A schematic cross-sectional view of a bulk acoustic resonator intercepted by the B-B' line. Figure 3C For an exemplary embodiment of the present invention, along Figure 2 A schematic cross-sectional view of the bulk acoustic resonator intercepted by the C-C' line. It can be seen that, in... Figure 3B and 3C In the middle, the top electrode of the lower resonator and the bottom electrode of the upper resonator are electrically connected in the circumferential direction around the entire acoustic mirror 201.

[0068] When the bottom electrode of the upper resonator and the top electrode of the lower resonator are electrically connected to each other, Figures 3A-3C In the structure shown, the bottom electrode of the upper resonator and the non-electrode connection terminals and electrode connection terminals of the top electrode of the lower resonator are all connected to each other, forming an electrical connection around the entire circumference of the acoustic mirror 201. However, besides... Figures 3A-3C In addition to the connection methods shown, there are other connection methods available.

[0069] Figure 5B For an exemplary embodiment of the present invention, along Figure 4 A schematic cross-sectional view of a bulk acoustic resonator intercepted by the B-B' line. Figure 5B In the upper resonator, the bottom electrode 202 and the top electrode 104 of the lower resonator are electrically connected to each other; that is, the electrode connection end of the bottom electrode 202 covers and is electrically connected to the electrode connection end of the top electrode 104. However, with Figure 3C Unlike in China, in Figure 5B In the middle, the non-electrode connection terminal of the top electrode 104 is not connected to the non-electrode connection terminal of the bottom electrode 202, such as Figure 5B As shown, the end of the non-electrode connection of the bottom electrode 202 of the upper resonator is located outside the non-electrode connection of the top electrode 104 of the lower resonator (spaced apart from the non-electrode connection of the top electrode 104 in the horizontal direction) and is disposed on the upper surface of the piezoelectric layer 103 of the lower resonator.

[0070] Figure 7B For an exemplary embodiment of the present invention, along Figure 6 A schematic cross-sectional view of a bulk acoustic resonator intercepted by the B-B' line. Figure 7B In the upper resonator, the bottom electrode 202 and the top electrode 104 of the lower resonator are electrically connected to each other; that is, the electrode connection end of the bottom electrode 202 covers and is electrically connected to the electrode connection end of the top electrode 104. Additionally, in Figure 7B In the middle, the non-electrode connection terminal of the top electrode 104 is not connected to the non-electrode connection terminal of the bottom electrode 202, such as Figure 7BAs shown, the non-electrode connection end of the bottom electrode 202 of the upper resonator is located inside the boundary of the acoustic mirror 201, and is not located on the upper surface of the piezoelectric layer 103 of the lower resonator.

[0071] Figure 9 This is a cross-sectional view of a resonator assembly according to an exemplary embodiment of the present invention, wherein the effective regions of the upper and lower resonators are acoustically isolated by a cavity. Figure 9 In the right-side view, the upper and lower resonators are electrically connected to each other.

[0072] like Figure 9 As shown in the right-hand cross-sectional view, the top electrode 104 is covered by a piezoelectric layer 103, and the bottom electrode 202 is connected to the top electrode 104 at both the electrode connection end and the non-electrode connection end. Figure 9 In the right-side view, the electrode connection end of the bottom electrode 202 covers the electrode connection end of the top electrode 104, and the non-electrode connection end of the bottom electrode 202 covers the non-electrode connection end of the top electrode 104.

[0073] exist Figure 9 The diagram shows process layers or passivation layers 105 and 205 disposed on the upper surface of the top electrode, which may or may not be disposed.

[0074] In this invention Figure 9 In the structure shown, since the second electrode layer where the bottom electrode 202 is located covers the first electrode layer where the top electrode 104 is located, the metal thickness of the bottom electrode of the upper resonator and the top electrode of the lower resonator at the electrode connection part can be increased, which is beneficial to reduce electrical losses.

[0075] When the ratio of the maximum effective width of the resonator to the cavity height is large, the upper and lower resonators may come into contact within the cavity due to bending or other reasons. For example, if the cavity height is... When the maximum width of the effective region of the resonator is greater than 100μm, in order to ensure the complete formation of the acoustic mirror 201 within the effective regions of the upper and lower resonators, the stress of the lower resonator can be controlled to bend it downward toward the air cavity, and / or the stress of the upper resonator can be controlled to bend it upward toward the air cavity. The top electrode of the lower resonator is concave downward, and / or the top electrode of the upper resonator is convex upward.

[0076] In the above embodiments, the bottom electrode of the upper resonator and the top electrode of the lower resonator are electrically connected to each other, but the present invention is not limited thereto. When two stacked bulk acoustic resonators share an acoustic decoupling layer, the bottom electrode of the upper resonator and the top electrode of the lower resonator can also be electrically isolated from each other.

[0077] Figure 5A For an exemplary embodiment of the present invention, along Figure 4 A schematic cross-sectional view of a bulk acoustic resonator intercepted by line A-A'. Figure 5A In the middle, the bottom electrode 202 of the upper resonator and the top electrode 104 of the lower resonator are not electrically connected. The non-electrode connection end of the bottom electrode 202 of the upper resonator is located outside the non-electrode connection end of the top electrode 104 of the lower resonator and is located on the upper surface of the piezoelectric layer 103 of the lower resonator.

[0078] Figure 5C For an exemplary embodiment of the present invention, along Figure 4 The diagram shows a schematic cross-sectional view of the bulk acoustic resonator taken along the C-C' line. The non-electrode connection terminal of the bottom electrode 202 of the upper resonator is not electrically connected to the non-electrode connection terminal of the top electrode 104 of the lower resonator, and the electrode connection terminal of the bottom electrode 202 of the upper resonator is not electrically connected to the top electrode 104 of the lower resonator. Figure 5C In the middle, the non-electrode connection end of the bottom electrode 202 of the upper resonator is located outside the non-electrode connection end of the top electrode 104 of the lower resonator and is located on the upper surface of the piezoelectric layer 103 of the lower resonator.

[0079] Figure 5D For another exemplary embodiment of the present invention, along Figure 4 A schematic cross-sectional view of a bulk acoustic resonator obtained by intercepting the C-C' line. Figure 5D and Figure 5C The difference is that, in Figure 5D In this process, an electrode layer of the same layer as the top electrode 104 is provided below the electrode connection end of the bottom electrode 202 to increase the electrode thickness of the electrode connection end of the bottom electrode 202, thereby reducing electrical losses.

[0080] Figure 7A For an exemplary embodiment of the present invention, along Figure 6 The schematic cross-sectional view of the bulk acoustic resonator taken by line A-A' shows that the non-electrode connection terminal of the bottom electrode 202 of the upper resonator is not electrically connected to the non-electrode connection terminal of the top electrode 104 of the lower resonator. A portion of the end of the non-electrode connection terminal of the bottom electrode 202 of the upper resonator is disposed on the upper surface of the piezoelectric layer 103 of the lower resonator (see Figure 103). Figure 7A (Left side of the image) while the other end is located inside the boundary of the acoustic mirror 201 in the lateral direction (see image). Figure 7A (The right side of the middle).

[0081] Figure 7C For an exemplary embodiment of the present invention, along Figure 6The diagram shows a schematic cross-sectional view of the bulk acoustic resonator taken along line C-C'. The non-electrode connection terminal of the bottom electrode 202 of the upper resonator is not electrically connected to the non-electrode connection terminal of the top electrode 104 of the lower resonator, nor is the electrode connection terminal of the bottom electrode 202 of the upper resonator electrically connected to the top electrode 104 of the lower resonator. The non-electrode connection terminal of the bottom electrode 202 is located inside the boundary of the acoustic mirror 201 in the horizontal direction.

[0082] Figure 9 In the left-hand view, the upper and lower resonators are electrically isolated from each other. Specifically, in Figure 9 In the left-hand view, the top electrode 104 is located in the first electrode layer, which includes the top electrode 104 and a non-top electrode layer located outside the non-electrode connection terminal of the top electrode 104 via the disconnection structure 106. Figure 9 (The left side of the broken structure 106). Figure 9 In the middle, the bottom electrode 202 is located in the second electrode layer, such as Figure 9 As shown in the left-hand view, the second electrode layer includes a bottom electrode 202 and a non-bottom electrode layer located outside the non-electrode connection terminal of the bottom electrode 202, electrically isolated from the non-electrode connection terminal of the bottom electrode 202 via a disconnection structure 206. Figure 9 (The right side of the disconnected structure 206). Figure 9 In the left-hand view, the electrode connection end of the bottom electrode 202 covers the non-top electrode layer, and the non-bottom electrode layer covers the electrode connection end of the top electrode 104.

[0083] In addition, controlling the stress can reduce the probability of the upper and lower resonators coming into contact with each other. However, when the resonator area is large, a support can be added. This support can contact the top or top electrode of the lower resonator, and the height of the support must be less than or equal to the cavity height. Equal means that the top of the support contacts the bottom or bottom electrode of the upper resonator. The height of the support is less than the cavity height, which means that the top of the support does not contact the upper resonator. When the cavity thickness is reduced locally due to the bending of the resonator, the top of the support will contact the upper resonator and play a supporting role.

[0084] The following description, with reference to the accompanying drawings, illustrates the positional relationship between the electrodes of the upper and lower resonators and the acoustic mirror 201 in the lateral direction.

[0085] Figure 3A For along Figure 2The diagram shows a schematic cross-sectional view of a bulk acoustic resonator intercepted by line A-A', illustrating the upper and lower resonators. The lower resonator consists of acoustic mirror 101, bottom electrode 102, piezoelectric layer 103, and top electrode 104 (passivation layer, load layer, etc., are omitted). The lower resonator also consists of acoustic mirror 201, bottom electrode 202, piezoelectric layer 203, and top electrode 204. Acoustic mirror 201 serves as the shared cavity for both the upper and lower resonators.

[0086] Figure 3A In the structure shown, the effective region of the lower resonator is determined by the overlapping area of ​​the acoustic mirror 101, the bottom electrode 102, the piezoelectric layer 103, and the top electrode 104 in the thickness direction, and A1 corresponds to the effective region of the lower resonator; the effective region of the upper resonator is determined by the overlapping area of ​​the acoustic mirror 201, the bottom electrode 202, the piezoelectric layer 203, and the top electrode 204 in the thickness direction, and A2 corresponds to the effective region of the upper resonator.

[0087] See the appendix below. Figure 3B-7D The above descriptions of the effective regions A1 and A2 also apply, and will not be repeated hereafter.

[0088] d1 corresponds to the distance (first distance) from the outer boundary of the acoustic mirror 201 to the non-electrode connection end of the bottom electrode 102 in the horizontal direction at the non-electrode connection end of the bottom electrode 102 of the lower resonator. d1 should be greater than 0, that is, the boundary of the acoustic mirror 201 is outside the bottom electrode 102 in the horizontal direction. This avoids the acoustic energy leakage area formed by the overlap of the bottom electrode 102, piezoelectric layer 103, and top electrode 104 without upper and lower cavity structures. This acoustic energy leakage area will cause a large amount of acoustic energy to be conducted to the substrate and ineffective areas, reducing the Q value of the resonator.

[0089] See the appendix below. Figure 3B-7D The above statement about d1 also applies to the description above, and will not be repeated hereafter.

[0090] d3 corresponds to the distance (third distance) from the outer edge of the acoustic energy leakage region formed by the overlap of the bottom electrode 102, piezoelectric layer 103, and top electrode 104 of the lower resonator, with a cavity structure on the top and no cavity structure on the bottom, to the boundary of the acoustic mirror 101 at the non-electrode connection end of the bottom electrode 102. In other words, the part of the bottom electrode 102 located in the horizontal direction between the boundary of the acoustic mirror 101 and the boundary of the acoustic mirror 201 forms a sandwich first structure with the piezoelectric layer 103 and the top electrode 104. The outer edge of the sandwich first structure has a distance d3 in the horizontal direction from the boundary of the acoustic mirror 101.

[0091] This sandwich-like first structure, which constitutes the acoustic energy leakage region, causes a large amount of acoustic energy to be conducted to the substrate and the ineffective region, reducing the Q value of the resonator. In an optional embodiment, d3 is less than or equal to 10 μm.

[0092] See the appendix below. Figure 3B-7D The above statement about d3 also applies to the description above, and will not be repeated hereafter.

[0093] d4 corresponds to the width of the region where the non-electrode connection end of the bottom electrode 202 of the lower resonator is electrically in contact with the first piezoelectric layer 103 and where there is no bottom electrode 102 below. Specifically, it is the horizontal distance (fourth distance) between the outer edge of the portion of the non-electrode connection end of the bottom electrode 202 of the lower resonator that is electrically in contact with the upper surface of the piezoelectric layer 103 and the non-electrode connection end of the bottom electrode 102. In other words, at least a portion of the non-electrode connection end of the bottom electrode 202 in the circumferential direction is located outside the non-electrode connection end of the bottom electrode 102 in the horizontal direction and is electrically in contact with the upper surface of the piezoelectric layer 103, and a horizontal distance d4 exists between the outer edge of the non-electrode connection end of the bottom electrode 202 and the non-electrode connection end of the bottom electrode 102.

[0094] In the region corresponding to d4, although there is no bottom electrode 102 directly below, it will form a weak electrical coupling with the edge (bottom electrode 102 in the region corresponding to d3), affecting the resonator performance. In an optional embodiment, d4 is less than or equal to 10 μm.

[0095] See the appendix below. Figure 3B-7D The above description of d4 also applies, and will not be repeated hereafter.

[0096] exist Figure 3A As can be seen, the end of the non-electrode connection of the bottom electrode 202 covers the end of the non-electrode connection of the top electrode 104 which is electrically connected.

[0097] d2 corresponds to the distance (second distance) from the boundary of the acoustic mirror 201 in the lateral direction to the non-electrode connection end of the top electrode 204 of the upper resonator at the non-electrode connection end of the top electrode 204. d2 should be greater than 0, that is, the boundary of the acoustic mirror 201 is located outside the non-electrode connection end of the top electrode 204 in the horizontal direction. This avoids the acoustic energy leakage area formed by the overlap of the bottom electrode 202, piezoelectric layer 203, and top electrode 204 without upper and lower cavity structures. This acoustic energy leakage area will cause a large amount of acoustic energy to be conducted to the substrate and ineffective areas, reducing the Q value of the resonator.

[0098] See the appendix below. Figure 3B-7D The above statement about d2 also applies to the description above, and will not be repeated hereafter.

[0099] Figure 3B For along Figure 2The schematic cross-sectional view of the bulk acoustic resonator obtained by the B-B' line shows the external lead 11 of the bottom electrode of the lower resonator and the external lead 12 of the top electrode of the lower resonator.

[0100] Figure 3B The diagram shows d1, d2, and d3, as well as A1 and A2.

[0101] exist Figure 3B In this context, d5 corresponds to the distance (fifth distance) between the outer edge of the acoustic energy leakage region formed by the overlapping of the bottom electrode 102, piezoelectric layer 103, and top electrode 104 of the lower resonator and the boundary of the acoustic mirror 201 in the horizontal direction at the electrode connection end of the bottom electrode 102. In other words, the portion of the non-electrode connection end of the bottom electrode 202 located outside the boundary of the acoustic mirror 201 forms a sandwich second structure with the bottom electrode 102 and the piezoelectric layer 103, and the outer end of the sandwich second structure has a distance d5 in the horizontal direction from the boundary of the acoustic mirror 201.

[0102] This sandwich-like second structure, serving as an acoustic energy leakage region, causes a significant amount of acoustic energy to be conducted to the substrate and ineffective regions, reducing the Q value of the resonator. The region corresponding to d5 is located at the non-electrode connection end of the top electrode 104. To minimize its impact on performance, in an optional embodiment, d5 is less than or equal to 10 μm.

[0103] See the appendix below. Figure 3B-7D The above description of d5 also applies, and will not be repeated hereafter.

[0104] Figure 3C For along Figure 2 The schematic cross-sectional view of the bulk acoustic resonator obtained by the C-C' line shows the external lead 13 of the bottom electrode of the upper resonator and the external lead 14 of the top electrode of the upper resonator.

[0105] Figure 3C The diagram shows d1, d2, d3, d4, and A1 and A2.

[0106] exist Figure 3C In this context, d6 corresponds to the distance (sixth distance) between the outer edge of the acoustic energy leakage region formed by the overlap of the bottom electrode 202, piezoelectric layer 203, and top electrode 204 of the upper resonator and the boundary of the acoustic mirror 201 in the horizontal direction at the electrode connection end of the top electrode 204. In other words, the portion of the non-electrode connection end of the bottom electrode 202 located outside the boundary of the acoustic mirror 201 forms a sandwich third structure with the top electrode 204 and the piezoelectric layer 203, and the outer end of the sandwich third structure has a distance d6 in the horizontal direction from the boundary of the acoustic mirror 201.

[0107] This sandwich-like third structure, serving as an acoustic energy leakage region, causes a significant amount of acoustic energy to be conducted to the substrate and ineffective regions, reducing the Q value of the resonator. The region corresponding to d6 is located at the non-electrode connection end of the bottom electrode 202. To minimize its impact on performance, in an optional embodiment, d6 is less than or equal to 10 μm.

[0108] To eliminate the image, for example Figure 3B The lower resonator shown in the diagram has an overlapping bottom electrode 102, piezoelectric layer 103, and top electrode 104, and no acoustic energy leakage region formed by the absence of cavity structures above and below, thus preventing the top electrode of the lower resonator from being connected to the bottom electrode of the upper resonator. This structure will be explained in detail below.

[0109] Figure 4 This is a schematic top view of a bulk acoustic resonator assembly according to another exemplary embodiment of the present invention. For emphasis, only the acoustic mirror 101 of the lower resonator, the bottom electrode 102 of the lower resonator, and the top electrode 104 of the upper resonator are shown, along with the external leads 11 and 12 of the lower resonator's electrodes and the external lead 13 of the bottom electrode of the upper resonator. Figure 4 In the middle, the boundary of the non-electrode connection end of the top electrode 104 is inside the boundary of the acoustic mirror 101, while the boundary of the acoustic mirror 101 is inside the boundary of the bottom electrode 102.

[0110] Figure 5A For along Figure 4 A schematic cross-sectional view of a bulk acoustic resonator obtained by the A-A' line. Figure 5A The diagram shows d1, d2, d4, and A1 and A2. Figure 5A In the middle, the non-electrode connection ends on the left and right sides of the bottom electrode 202 are located outside the non-electrode connection ends of the top electrode 104 in the lateral direction and are spaced apart from them.

[0111] Figure 5B For along Figure 4 The schematic cross-sectional view of the bulk acoustic resonator obtained by the B-B' line also shows the external lead 11 of the bottom electrode of the lower resonator and the external lead 12 of the top electrode of the lower resonator. Figure 5B The diagram shows d1, d2, d3, d5, and A1 and A2. In Figure 5B In the middle, the non-electrode connection end on the left side of the bottom electrode 202 (the area where d5 is located) is located outside the non-electrode connection end of the top electrode 104 in the lateral direction and is spaced apart from it, while the electrode connection end of the bottom electrode 202 covers the electrode connection end of the top electrode 104 and is electrically connected to it.

[0112] Figure 5C for Figure 4The schematic cross-sectional view of the bulk acoustic resonator obtained by the C-C' line also shows the external lead 13 of the bottom electrode of the upper resonator and the external lead 14 of the top electrode of the upper resonator. Figure 5C The diagram shows d1, d2, d4, d6, and A1 and A2. Figure 5C In the middle, the non-electrode connection end on the left side of the bottom electrode 202 (the area where d6 is located) is located outside the non-electrode connection end of the top electrode 104 in the lateral direction and is separated from it, while the electrode connection end of the bottom electrode 202 is also electrically isolated from the electrode connection end of the top electrode 104.

[0113] Figure 5D For similar to along Figure 4 The schematic cross-sectional view of the bulk acoustic resonator obtained by the C-C' line shows the external lead 13 of the bottom electrode of the upper resonator and the external lead 14 of the top electrode of the upper resonator. Figure 5D The diagram shows d1, d2, d4, d6, as well as A1 and A2. Figure 5D and Figure 5C The difference in the structure shown is that, Figure 5D In the middle, an electrode layer of the same layer as the top electrode 104 is provided below the electrode connection end of the bottom electrode 202 to increase the thickness of the electrode connection end of the bottom electrode 202, thereby reducing the loss.

[0114] Figure 6 This is a schematic top view of a bulk acoustic resonator assembly according to another exemplary embodiment of the present invention, which mainly shows the positional relationship between the bottom electrode 202 of the upper resonator and the acoustic mirror 201, as well as the external lead 12 of the top electrode of the lower resonator and the external lead 13 of the bottom electrode of the upper resonator.

[0115] Figure 7A For along Figure 6 A schematic cross-sectional view of a bulk acoustic resonator obtained by the A-A' line. Figure 7A The diagram shows d1, d2, d4, and A1 and A2.

[0116] It should be pointed out that, Figure 7A and Figure 5A The difference in the structure shown is that, Figure 7A The structure corresponding to d4 on the right disappears, thus reducing the impact of the presence of the region corresponding to d4 on the resonator performance.

[0117] Figure 7B For along Figure 6 The schematic cross-sectional view of the bulk acoustic resonator obtained by the B-B' line shows the external lead 11 of the bottom electrode of the lower resonator and the external lead 12 of the top electrode of the lower resonator. Figure 7B The diagram shows d1, d2, d3, as well as A1 and A2. Figure 7B and Figure 5B The difference is that, in Figure 5B In the middle, the non-electrode connection end on the left side of the bottom electrode 202 (the area where d5 is located) is located outside and spaced apart from the non-electrode connection end of the top electrode 104 in the lateral direction, while... Figure 7B In the middle, the non-electrode connection end of the bottom electrode 202 is not located outside the boundary of the acoustic mirror 201, thus eliminating... Figure 5B The influence of the region corresponding to d5 on the performance of the resonator.

[0118] Figure 7C For along Figure 6 The schematic cross-sectional view of the bulk acoustic resonator obtained by the C-C' line shows the external lead 13 of the bottom electrode of the upper resonator and the external lead 14 of the top electrode of the upper resonator. Figure 7C The diagram shows d1, d2, and A1 and A2. Figure 7C and Figure 5C The difference in the structure shown is that, Figure 5C In the middle, the non-electrode connection end on the left side of the bottom electrode 202 (the area where d6 is located) is located outside and spaced apart from the non-electrode connection end of the top electrode 104 in the lateral direction, while... Figure 7C In the middle, the non-electrode connection end of the bottom electrode 202 is not located outside the boundary of the acoustic mirror 201, thus eliminating... Figure 5C The influence of the region corresponding to d6 on the performance of the resonator.

[0119] Figure 7D For similar to along Figure 6 A schematic cross-sectional view of a bulk acoustic resonator obtained by intercepting the C-C' line. Figure 7D exist Figure 7C Based on this, a metal layer of the top electrode of the lower resonator is added at the electrode lead 13 of the bottom electrode of the upper resonator to reduce lead resistance loss. Figure 7D The diagram shows d1, d2, and A1 and A2.

[0120] In the above embodiments, the boundary of the acoustic mirror 201 is located outside the non-electrode connection end of the top electrode 204 or the top electrode 104 in the lateral direction; however, the present invention is not limited thereto. In another embodiment, the boundary of the acoustic mirror 201 is located inside the non-electrode connection end of the bottom electrode 102 in the horizontal direction, and the distance between them is in the range of 0 to -10 μm; and / or the boundary of the acoustic mirror 201 is located inside the non-electrode connection end of the top electrode 204 in the horizontal direction, and the distance between them is in the range of 0 to -10 μm.

[0121] It should be noted that, in this invention, each numerical range, except where explicitly stated not to include endpoint values, can be either an endpoint value or the median of each numerical range, and all of these are within the protection scope of this invention.

[0122] In this invention, "upper" and "lower" are relative to the bottom surface of the resonator's base. For a component, the side closer to the bottom surface is the lower side, and the side farther from the bottom surface is the upper side.

[0123] In this invention, "inner" and "outer" refer to the center of the effective region of the resonator (i.e., the center of the effective region) in the lateral or radial direction. The side or end of a component closer to the center of the effective region is called the inner side or inner end, while the side or end of the component farther from the center of the effective region is called the outer side or outer end. For a reference position, being inside the position means being between that position and the center of the effective region in the lateral or radial direction, while being outside the position means being farther from the center of the effective region in the lateral or radial direction than that position.

[0124] As those skilled in the art will understand, the bulk acoustic resonator according to the present invention can be used to form filters or electronic devices. These electronic devices include, but are not limited to, intermediate products such as RF front-ends and filtering / amplifying modules, as well as terminal products such as mobile phones, Wi-Fi devices, and drones.

[0125] Based on the above, the present invention proposes the following technical solution:

[0126] 1. A bulk acoustic resonator assembly, comprising:

[0127] Base;

[0128] At least two resonators, which are bulk acoustic wave resonators, are stacked on one side of a substrate in the thickness direction of the substrate. The at least two resonators include a first resonator and a second resonator, with the second resonator above the first resonator. The first resonator has a first top electrode, a first piezoelectric layer, a first bottom electrode, and a first acoustic mirror. The second resonator has a second top electrode, a second piezoelectric layer, a second bottom electrode, and a second acoustic mirror.

[0129] in:

[0130] An acoustic decoupling layer in the form of a cavity is provided between the first top electrode and the second bottom electrode, and the acoustic decoupling layer serves as the second acoustic mirror;

[0131] The boundary of the cavity is located outside the non-electrode connection end of the first bottom electrode in the horizontal direction; and

[0132] The boundary of the cavity is located outside the non-electrode connection end of the second top electrode in the horizontal direction.

[0133] 2. The component according to 1, wherein:

[0134] The first bottom electrode is located in the horizontal direction between the boundary of the first acoustic mirror and the boundary of the cavity, forming a sandwich first structure with the first piezoelectric layer and the first top electrode. The outer edge of the sandwich first structure has a third distance in the horizontal direction from the boundary of the first acoustic mirror.

[0135] 3. The component according to 1, wherein:

[0136] At least a portion of the non-electrode connection end of the second bottom electrode in the circumferential direction is located outside the non-electrode connection end of the first bottom electrode in the horizontal direction and is in electrical contact with the upper surface of the first piezoelectric layer. The outer edge of the non-electrode connection end of the second bottom electrode and the non-electrode connection end of the first bottom electrode have a fourth distance in the horizontal direction.

[0137] 4. The component according to 3, wherein:

[0138] The non-electrode connection ends of the second bottom electrode are all located outside the non-electrode connection ends of the first bottom electrode in the circumferential direction.

[0139] 5. The component according to 3, wherein:

[0140] At least a portion of the non-electrode connection end of the second bottom electrode is located inside the boundary of the cavity in the circumferential direction.

[0141] 6. The component according to 5, wherein:

[0142] The non-electrode connection end of the first top electrode is located inside the boundary of the first acoustic mirror in the horizontal direction.

[0143] 7. The component according to 1, wherein:

[0144] The portion of the non-electrode connection end of the second bottom electrode located outside the boundary of the cavity forms a sandwich second structure with the first bottom electrode and the first piezoelectric layer. The outer end of the sandwich second structure is at a fifth distance from the boundary of the cavity in the horizontal direction.

[0145] 8. The component according to 7, wherein:

[0146] The portion of the non-electrode connection end of the second bottom electrode located outside the boundary of the cavity is horizontally spaced from the non-electrode connection end of the first top electrode.

[0147] 9. The component according to claim 1, wherein:

[0148] The portion of the non-electrode connection end of the second bottom electrode located outside the boundary of the cavity forms a sandwich third structure with the second top electrode and the second piezoelectric layer. The outer end of the sandwich third structure is at a sixth distance from the boundary of the cavity in the horizontal direction.

[0149] 10. The component according to 9, wherein:

[0150] The portion of the non-electrode connection end of the second bottom electrode located outside the boundary of the cavity is horizontally spaced from the non-electrode connection end of the first top electrode.

[0151] 11. The component according to any one of 2-10, wherein:

[0152] The distance is no greater than 10 μm.

[0153] 12. The component according to claim 1, wherein:

[0154] The resonant frequency of the first resonator is greater than 0.5 GHz, and the thickness of the first top electrode is less than... and / or

[0155] The resonant frequency of the second resonator is greater than 0.5 GHz, and the thickness of the second bottom electrode is less than...

[0156] 13. The component according to 12, wherein:

[0157] The resonant frequency of the first resonator is greater than 3 GHz, and the thickness of the first top electrode is less than... and / or

[0158] The resonant frequency of the second resonator is greater than 3 GHz, and the thickness of the second bottom electrode is less than...

[0159] 14. The component according to any one of 1-13, wherein:

[0160] The first top electrode and the second bottom electrode are electrically connected to each other.

[0161] 15. The component according to 14, wherein:

[0162] The electrode connection portion of the second bottom electrode covers the electrode connection portion of the first top electrode and forms an electrical connection with the electrode connection portion of the first top electrode.

[0163] 16. The component according to 14 or 15, wherein:

[0164] The component is the component according to any one of 1-4 and 7-13, wherein:

[0165] The non-electrode connection end of the second bottom electrode covers the non-electrode connection end of the first top electrode and they are connected to each other to form a common connection part.

[0166] 17. The component according to 16, wherein:

[0167] The length of the connection path between the first top electrode and the second bottom electrode at their non-connection ends is less than 5 μm.

[0168] 18. The component according to any one of 1-13, wherein:

[0169] The first top electrode and the second bottom electrode are electrically isolated from each other.

[0170] 19. The component according to 18, wherein:

[0171] The component includes a first electrode layer and a second electrode layer;

[0172] The first electrode layer includes a first top electrode and a non-top electrode layer that is electrically isolated from the non-electrode connection terminal of the first top electrode and located outside the non-electrode connection terminal of the first top electrode;

[0173] The second electrode layer includes a second bottom electrode and a non-bottom electrode layer that is electrically isolated from the non-electrode connection terminal of the second bottom electrode and located outside the non-electrode connection terminal of the second bottom electrode;

[0174] The electrode connection end of the second bottom electrode covers the non-top electrode layer, and the non-bottom electrode layer covers the electrode connection end of the first top electrode.

[0175] 20. A bulk acoustic resonator assembly, comprising:

[0176] Base;

[0177] At least two resonators, which are bulk acoustic wave resonators, are stacked on one side of a substrate in the thickness direction of the substrate. The at least two resonators include a first resonator and a second resonator, with the second resonator above the first resonator. The first resonator has a first top electrode, a first piezoelectric layer, a first bottom electrode, and a first acoustic mirror. The second resonator has a second top electrode, a second piezoelectric layer, a second bottom electrode, and a second acoustic mirror.

[0178] in:

[0179] An acoustic decoupling layer in the form of a cavity is provided between the first top electrode and the second bottom electrode, and the acoustic decoupling layer serves as the second acoustic mirror;

[0180] The boundary of the cavity is located inside the non-electrode connection end of the first bottom electrode in the horizontal direction, and the distance between them is in the range of 0 to -10 μm; and

[0181] The boundary of the cavity is located inside the non-electrode connection end of the second top electrode in the horizontal direction, and the distance between them is in the range of 0 to -10 μm.

[0182] 21. A bulk acoustic resonator assembly, comprising:

[0183] At least two resonators are stacked adjacent to each other from bottom to top in the thickness direction of the component. The at least two resonators are bulk acoustic wave resonators, and the at least two resonators include a first resonator and a second resonator.

[0184] in:

[0185] An acoustic decoupling layer in the form of a cavity is provided between the top electrode of the first resonator and the bottom electrode of the second resonator, and the acoustic decoupling layer serves as an acoustic mirror of the second resonator.

[0186] The boundary of the cavity is located horizontally outside the non-electrode connection end of the bottom electrode of the first resonator; and

[0187] The boundary of the cavity is located outside the non-electrode connection end of the top electrode of the second resonator in the horizontal direction.

[0188] 22. The component according to 1, 20, or 21, wherein:

[0189] The at least two resonators include a first resonator, a second resonator, and a third resonator stacked in the thickness direction;

[0190] The first acoustic decoupling layer is located between the top electrode of the first resonator and the bottom electrode of the second resonator, and the second acoustic decoupling layer is located between the top electrode of the second resonator and the bottom electrode of the third resonator in the form of a cavity. The second acoustic decoupling layer constitutes the acoustic mirror of the third resonator.

[0191] 23. A filter comprising a bulk acoustic resonator assembly according to any one of 1-22.

[0192] 24. An electronic device comprising the filter according to claim 23 or the bulk acoustic resonator assembly according to any one of claims 1-22.

[0193] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that variations may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A bulk acoustic resonator assembly, comprising: Base; At least two resonators, which are bulk acoustic wave resonators, are stacked on one side of a substrate in the thickness direction of the substrate. The at least two resonators include a first resonator and a second resonator, with the second resonator above the first resonator. The first resonator has a first top electrode, a first piezoelectric layer, a first bottom electrode, and a first acoustic mirror. The second resonator has a second top electrode, a second piezoelectric layer, a second bottom electrode, and a second acoustic mirror. in: An acoustic decoupling layer in the form of a cavity is provided between the first top electrode and the second bottom electrode, and the acoustic decoupling layer serves as the second acoustic mirror; The boundary of the cavity is located outside the non-electrode connection end of the first bottom electrode in the horizontal direction; and The boundary of the cavity is located outside the non-electrode connection end of the second top electrode in the horizontal direction; The cavity is formed based on the support of the second bottom electrode in the thickness direction; The first bottom electrode is located in the horizontal direction between the boundary of the first acoustic mirror and the boundary of the cavity, forming a sandwich first structure with the first piezoelectric layer and the first top electrode. The outer edge of the sandwich first structure has a third distance in the horizontal direction from the boundary of the first acoustic mirror.

2. The component according to claim 1, wherein: At least a portion of the non-electrode connection end of the second bottom electrode in the circumferential direction is located outside the non-electrode connection end of the first bottom electrode in the horizontal direction and is in electrical contact with the upper surface of the first piezoelectric layer. The outer edge of the non-electrode connection end of the second bottom electrode and the non-electrode connection end of the first bottom electrode have a fourth distance in the horizontal direction.

3. The component according to claim 2, wherein: The non-electrode connection ends of the second bottom electrode are all located outside the non-electrode connection ends of the first bottom electrode in the circumferential direction.

4. The component according to claim 2, wherein: At least a portion of the non-electrode connection end of the second bottom electrode is located inside the boundary of the cavity in the circumferential direction.

5. The component according to claim 4, wherein: The non-electrode connection end of the first top electrode is located inside the boundary of the first acoustic mirror in the horizontal direction.

6. The component according to claim 1, wherein: The portion of the non-electrode connection end of the second bottom electrode located outside the boundary of the cavity forms a sandwich second structure with the first bottom electrode and the first piezoelectric layer. The outer end of the sandwich second structure is at a fifth distance from the boundary of the cavity in the horizontal direction.

7. The component according to claim 6, wherein: The portion of the non-electrode connection end of the second bottom electrode located outside the boundary of the cavity is horizontally spaced from the non-electrode connection end of the first top electrode.

8. The component according to claim 1, wherein: The portion of the non-electrode connection end of the second bottom electrode located outside the boundary of the cavity forms a sandwich third structure with the second top electrode and the second piezoelectric layer. The outer end of the sandwich third structure is at a sixth distance from the boundary of the cavity in the horizontal direction.

9. The component according to claim 8, wherein: The portion of the non-electrode connection end of the second bottom electrode located outside the boundary of the cavity is horizontally spaced from the non-electrode connection end of the first top electrode.

10. The component according to any one of claims 1-9, wherein: The third distance is no greater than 10 μm.

11. The component according to claim 1, wherein: The resonant frequency of the first resonator is greater than 0.5 GHz, and the thickness of the first top electrode is less than 5000 Å; and / or The resonant frequency of the second resonator is greater than 0.5 GHz, and the thickness of the second bottom electrode is less than 5000 Å.

12. The component of claim 11, wherein: The resonant frequency of the first resonator is greater than 3 GHz, and the thickness of the first top electrode is less than 2000 Å; and / or The resonant frequency of the second resonator is greater than 3 GHz, and the thickness of the second bottom electrode is less than 2000 Å.

13. The component according to any one of claims 1-9, 11 and 12, wherein: The first top electrode and the second bottom electrode are electrically connected to each other.

14. The component of claim 13, wherein: The electrode connection portion of the second bottom electrode covers the electrode connection portion of the first top electrode and forms an electrical connection with the electrode connection portion of the first top electrode.

15. The component according to any one of claims 1-3, 6-9, 11, and 12, wherein: The non-electrode connection end of the second bottom electrode covers the non-electrode connection end of the first top electrode and they are connected to each other to form a common connection part.

16. The component of claim 15, wherein: The length of the connection path between the first top electrode and the second bottom electrode at their non-connection ends is less than 5 μm.

17. The component according to any one of claims 1-9, 11 and 12, wherein: The first top electrode and the second bottom electrode are electrically isolated from each other.

18. The component of claim 17, wherein: The component includes a first electrode layer and a second electrode layer; The first electrode layer includes a first top electrode and a non-top electrode layer that is electrically isolated from the non-electrode connection terminal of the first top electrode and located outside the non-electrode connection terminal of the first top electrode; The second electrode layer includes a second bottom electrode and a non-bottom electrode layer that is electrically isolated from the non-electrode connection terminal of the second bottom electrode and located outside the non-electrode connection terminal of the second bottom electrode; The electrode connection end of the second bottom electrode covers the non-top electrode layer, and the non-bottom electrode layer covers the electrode connection end of the first top electrode.

19. A bulk acoustic resonator assembly, comprising: Base; At least two resonators, which are bulk acoustic wave resonators, are stacked on one side of a substrate in the thickness direction of the substrate. The at least two resonators include a first resonator and a second resonator, with the second resonator above the first resonator. The first resonator has a first top electrode, a first piezoelectric layer, a first bottom electrode, and a first acoustic mirror. The second resonator has a second top electrode, a second piezoelectric layer, a second bottom electrode, and a second acoustic mirror. in: An acoustic decoupling layer in the form of a cavity is provided between the first top electrode and the second bottom electrode, and the acoustic decoupling layer serves as the second acoustic mirror; The boundary of the cavity is located inside the non-electrode connection end of the first bottom electrode in the horizontal direction, and the distance between them is in the range of 0 to -10 μm; and / or The boundary of the cavity is located inside the non-electrode connection end of the second top electrode in the horizontal direction, and the distance between them is in the range of 0 to -10 μm. The first bottom electrode is located in the horizontal direction between the boundary of the first acoustic mirror and the boundary of the cavity, forming a sandwich first structure with the first piezoelectric layer and the first top electrode. The outer edge of the sandwich first structure has a third distance in the horizontal direction from the boundary of the first acoustic mirror.

20. A bulk acoustic resonator assembly, comprising: At least two resonators are stacked adjacent to each other from bottom to top in the thickness direction of the component. The at least two resonators are bulk acoustic wave resonators, and the at least two resonators include a first resonator and a second resonator. in: An acoustic decoupling layer in the form of a cavity is provided between the top electrode of the first resonator and the bottom electrode of the second resonator, and the acoustic decoupling layer serves as an acoustic mirror of the second resonator. The boundary of the cavity is located horizontally outside the non-electrode connection end of the bottom electrode of the first resonator; and The boundary of the cavity is located outside the non-electrode connection end of the top electrode of the second resonator in the horizontal direction; The bottom electrode, piezoelectric layer and top electrode of the first resonator form a sandwich first structure, and the outer edge of the sandwich first structure has a third distance in the horizontal direction from the boundary of the acoustic mirror of the first resonator.

21. The component according to claim 1, 19, or 20, wherein: The at least two resonators include a first resonator, a second resonator, and a third resonator stacked in the thickness direction; There is a first acoustic decoupling layer between the top electrode of the first resonator and the bottom electrode of the second resonator, and there is a second acoustic decoupling layer in the form of a cavity between the top electrode of the second resonator and the bottom electrode of the third resonator. The second acoustic decoupling layer constitutes the acoustic mirror of the third resonator.

22. A filter comprising a bulk acoustic resonator assembly according to any one of claims 1-21.

23. An electronic device comprising the filter of claim 22 or the bulk acoustic resonator assembly of any one of claims 1-21.

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