Resonator, filter, electronic device, and method for manufacturing resonator

Abstract

The application provides a resonator, a filter, an electronic device and a manufacturing method of the resonator. The resonator comprises a substrate, a sandwich electrode, an acoustic mirror, a bottom electrode structure, a piezoelectric layer and a top electrode, the bottom electrode structure and the sandwich electrode are collectively arranged outside the acoustic mirror, the sandwich electrode and the bottom electrode structure are connected and conductive to each other, the bottom electrode structure comprises a seed layer, a first bottom electrode layer and a second bottom electrode layer, the first bottom electrode layer is formed on the seed layer, and the second bottom electrode layer is formed on the first bottom electrode layer and covers the first bottom electrode layer; and the overlapping parts of the acoustic mirror, the bottom electrode structure, the piezoelectric layer and the top electrode collectively form an effective area of the resonator. The application has good resonator performance.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and in particular to a resonator, filter, electronic device, and a method for manufacturing the resonator. Background Technology

[0002] As modern wireless communication technology develops towards higher frequencies and higher speeds, filter devices such as filters and duplexers based on resonators, such as film bulk acoustic resonators (FBARs), are becoming increasingly popular in the market.

[0003] Current resonators consist of a substrate and sequentially stacked layers on it, including an acoustic mirror, a lower electrode, a piezoelectric layer, and a upper electrode. Resonator fabrication involves processes such as film deposition and photolithography. The lower and upper electrode layers are typically formed by the deposition and growth of metallic materials. The crystal orientation of these electrode layers affects the crystal orientation growth of the piezoelectric layer, thus further influencing the resonator's performance. Therefore, a seed layer is formed before the lower electrode layers. This seed layer induces the vertical crystal orientation growth of the electrode layers, ensuring a favorable crystal orientation and optimizing the resonator's performance.

[0004] However, the materials that make up the seed layer, such as aluminum nitride, are prone to chemical reactions when in contact with air, or become contaminated when exposed to air for a long time. As a result, the surface of the seed layer will have impurities, which will affect the growth of the electrode film layer and have an adverse effect on the performance of the resonator. Summary of the Invention

[0005] This invention provides a resonator, a filter, an electronic device, and a method for manufacturing the resonator, which has good resonator performance.

[0006] To achieve the above objectives, in a first aspect, the present invention provides a resonator comprising:

[0007] Substrate;

[0008] Sandwich electrode;

[0009] Acoustic mirror;

[0010] The bottom electrode structure and the sandwich electrode are together surrounding the outside of the acoustic mirror. The sandwich electrode and the bottom electrode structure are interconnected and conductive. The bottom electrode structure includes a seed layer, a first bottom electrode layer and a second bottom electrode layer. The first bottom electrode layer is disposed on the seed layer, and the second bottom electrode layer is formed on the first bottom electrode layer and covers the first bottom electrode layer.

[0011] piezoelectric layer, and

[0012] Top electrode;

[0013] The overlapping portion of the sandwich electrode, acoustic mirror, bottom electrode structure, piezoelectric layer, and top electrode together forms the effective region of the resonator.

[0014] In one alternative implementation, the first bottom electrode layer is continuously formed on the seed layer.

[0015] In one alternative implementation, the first bottom electrode layer and the seed layer are deposited sequentially.

[0016] In one alternative implementation, the first bottom electrode layer and the seed layer have the same shape.

[0017] In one alternative implementation, in the lateral direction of the resonator, the second bottom electrode layer extends to the outside of the edge of the first bottom electrode layer.

[0018] In one alternative implementation, the height of the portion of the second bottom electrode layer covering the first bottom electrode layer is higher than the height of the portion not covering the first bottom electrode layer, so that the second bottom electrode layer has a stepped portion at the position corresponding to the edge of the first bottom electrode layer.

[0019] In one alternative implementation, the thickness of the second bottom electrode layer is greater than the thickness of the first bottom electrode layer.

[0020] In one alternative implementation, the thickness of the first bottom electrode layer is greater than or equal to and less than or equal to .

[0021] In one alternative implementation, the materials constituting the first bottom electrode layer and the second bottom electrode layer can be the same, while in other alternative implementations, the materials constituting the first bottom electrode layer and the second bottom electrode layer can be different.

[0022] In one alternative implementation, the seed layer material includes at least one of aluminum nitride, zinc oxide, and lead zirconate titanate.

[0023] In one alternative implementation, the material of the first bottom electrode layer includes at least one of molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, and chromium; and / or,

[0024] The material of the second bottom electrode layer includes at least one of molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, and chromium.

[0025] In one alternative implementation, the sandwich electrode is disposed on the substrate.

[0026] In one alternative implementation, the acoustic mirror includes a Bragg reflector or an air cavity.

[0027] In one alternative implementation, the acoustic mirror includes an air cavity; a sandwich electrode and a bottom electrode structure together surround the outside of the air cavity.

[0028] In one alternative implementation, the material of the sandwich electrode includes at least one of molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, and chromium.

[0029] In one alternative implementation, the resonator further includes an etch barrier layer disposed on the sandwich electrode.

[0030] In one alternative approach, the etch barrier layer is located within the air cavity.

[0031] In one alternative implementation, the resonator also includes a passivation layer that covers the top electrode.

[0032] It is understandable that the passivation layer is not a necessary layer structure in the resonator. Therefore, the resonator may or may not contain a passivation layer.

[0033] Secondly, the present invention also provides a filter, including the resonator described above.

[0034] Thirdly, the present invention also provides an electronic device including the filter described above.

[0035] Fourthly, the present invention provides a method for manufacturing a resonator, comprising:

[0036] A substrate is provided, and then a sandwich electrode is formed on the substrate, and an acoustic mirror or a sacrificial layer corresponding to the acoustic mirror is formed on the sandwich electrode; then a seed layer and a first bottom electrode layer are continuously formed on the substrate with the acoustic mirror or sacrificial layer; a second bottom electrode layer is formed on the first bottom electrode layer; finally, a piezoelectric layer and a top electrode are formed sequentially on the second bottom electrode layer.

[0037] In one alternative implementation, the seed layer and the first bottom electrode layer are formed sequentially, specifically including the sequential deposition and patterning of the seed layer and the first bottom electrode layer on a substrate having an acoustic mirror or a sacrificial layer.

[0038] In one alternative implementation, a second bottom electrode layer is formed on the first bottom electrode layer, specifically including depositing and patterning the second bottom electrode layer on the first bottom electrode layer, wherein the second bottom electrode layer covers the first bottom electrode layer.

[0039] In one alternative implementation, the acoustic mirror is an air cavity; a sandwich electrode is formed on the substrate, and an acoustic mirror or a corresponding sacrificial layer is formed on the sandwich electrode. Specifically, this may include: first forming a sandwich electrode on the substrate, then depositing an etch barrier layer and a sacrificial layer material on the sandwich electrode, and then forming a sacrificial layer by patterning the etch barrier layer and the sacrificial layer material. The sacrificial layer is used to form an air cavity after being removed.

[0040] In one alternative implementation, after the seed layer and the first bottom electrode layer are sequentially formed on the substrate with the acoustic mirror, the sacrificial layer is removed to form an air cavity.

[0041] The structure of the present invention, as well as its other inventive objects and beneficial effects, will become more apparent from the description of preferred embodiments taken in conjunction with the accompanying drawings. Attached Figure Description

[0042] Figure 1 A top view schematic diagram of the resonator provided in the embodiments of this application;

[0043] Figure 2 yes Figure 1 A sectional view obtained by cutting along AO-A';

[0044] Figure 3 This is a schematic diagram comparing the effective electromechanical coupling coefficient of the resonator in this embodiment and a conventional resonator;

[0045] Figure 4 yes Figure 2 A magnified view of a portion of point B in the middle;

[0046] Figure 5 This is a schematic diagram of another resonator structure provided in an embodiment of this application;

[0047] Figure 6 This is a schematic diagram of the steps in the resonator manufacturing method provided in this application;

[0048] Figure 7 According to Figure 6 A schematic diagram of the resonator structure after step S101, corresponding to the resonator manufacturing method;

[0049] Figure 8 According to Figure 6 A schematic diagram of the resonator structure after step S102, corresponding to the resonator manufacturing method;

[0050] Figure 9 According to Figure 6 A schematic diagram of the resonator structure after step S103, corresponding to the resonator manufacturing method;

[0051] Figure 10 According to Figure 6 A schematic diagram of the resonator structure after step S104, corresponding to the resonator manufacturing method;

[0052] Figure 11 According to Figure 6 A schematic diagram of the structure of the resonator after step S105, corresponding to the resonator manufacturing method;

[0053] Figure 12 According to Figure 6 A schematic diagram of the structure of the resonator corresponding to the intermediate resonator manufacturing method, after step S105, where the top electrode is formed;

[0054] Figure 13 According to Figure 6 A schematic diagram of the structure of the resonator corresponding to the medium resonator manufacturing method, after step S105, where a top electrode with a passivation layer is formed.

[0055] Figure 14 A schematic diagram illustrating the specific steps of forming a sandwich electrode on a substrate and forming an acoustic mirror or a sacrificial layer corresponding to the acoustic mirror on the sandwich electrode, as provided in an embodiment of this application.

[0056] Figure 15 This is a schematic diagram of the resonator structure corresponding to step S201 in the resonator fabrication method provided in this application embodiment;

[0057] Figure 16 This is a schematic diagram of the resonator structure corresponding to step S202 in the resonator fabrication method provided in the embodiments of this application;

[0058] Figure 17 This is a schematic diagram of the resonator structure corresponding to step S203 in the resonator fabrication method provided in this application embodiment;

[0059] Figure 18 This is a schematic diagram illustrating another specific step in forming a sandwich electrode on a substrate and forming an acoustic mirror or a sacrificial layer corresponding to the acoustic mirror on the sandwich electrode, as provided in an embodiment of this application.

[0060] Explanation of reference numerals in the attached figures:

[0061] 1-Substrate; 2-Air cavity; 3, 3'-Bottom electrode structure; 4-Piezoelectric layer; 5-Top electrode; 6-Passivation layer; 7-Interlayer electrode; 8-Etching barrier layer;

[0062] 21 - Sacrificial layer; 31, 31' - Seed layer; 32, 32' - First bottom electrode layer; 33, 33' - Second bottom electrode layer;

[0063] 331 - Stepped section; 100, 200 - Resonators. Detailed Implementation

[0064] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0065] Resonators are common electronic devices used in filtering systems such as filters. Current resonators can include types such as thin-film bulk acoustic wave (TFT-SA) resonators. Taking a commonly used TFT-SA resonator as an example, it is specifically formed by a multilayer stacked structure. This multilayer stacked structure includes two opposing planar electrodes and a piezoelectric material disposed between the two planar electrodes. When a voltage is applied to the planar electrodes, the piezoelectric material generates acoustic waves, thus forming resonance. The planar electrodes and piezoelectric material are arranged in a stacked film structure within the resonator, and each film layer is typically formed by growth or deposition. For example, the planar electrodes can be in the form of electrode films, and the piezoelectric material can be formed in the form of piezoelectric layers within the resonator. To ensure that the electrode films or piezoelectric layers have good crystal orientation during formation and thus better performance, a seed layer can be placed below the electrode films to induce the formation of the crystal orientation within the electrode films.

[0066] In existing resonators, when using a seed layer to induce the electrode film to form a better crystal orientation, the seed layer's material properties mean that it may react with water or oxygen in the air upon direct contact, forming impurities on its surface or becoming contaminated. For example, seed layers made of materials such as aluminum nitride are prone to hydrolysis in air, producing impurities. These impurities interfere with the stability of the seed layer itself, weakening its ability to induce the electrode film to form a perpendicular crystal orientation. Therefore, as the crystal orientation of the electrode film changes, it affects the crystal growth of the piezoelectric layer, thus adversely impacting the overall performance of the resonator. Specifically, the crystal orientation of the piezoelectric layer affects the resonator's effective electromechanical coupling coefficient, series resonant impedance, parallel resonant impedance, and quality factor, among other performance parameters.

[0067] Therefore, in the process of forming the seed layer, this application wraps the seed layer to avoid the seed layer being exposed to air for too long, thereby slowing down and avoiding the chemical reaction that occurs in the seed layer, and enabling the resonator to have better working performance.

[0068] The resonator of the present application embodiment is described in detail below with reference to the accompanying drawings.

[0069] First, the materials of each layer in the resonator appearing in this application will be described.

[0070] The substrate material can be one of the following: single crystal silicon, gallium nitride, gallium arsenide, sapphire, quartz, silicon carbide, diamond, or single crystal piezoelectric substrates such as lithium niobate, lithium tantalate, or potassium niobate.

[0071] The seed layer material can be aluminum nitride (AlN), zinc oxide (ZnO), single-crystal lead zirconate titanate (PZT), or rare earth element doped materials containing one or more of the above materials.

[0072] The piezoelectric layer can be a single-crystal piezoelectric material. Examples of single-crystal piezoelectric materials constituting the piezoelectric layer include: single-crystal aluminum nitride, single-crystal gallium nitride (GaN), single-crystal lithium niobate (LiNbO3), single-crystal lead zirconate titanate (PZT), single-crystal potassium niobate (KNbO3), single-crystal quartz film, or single-crystal lithium tantalate (LiTaO3). The piezoelectric layer can also be a polycrystalline piezoelectric material (as opposed to single-crystal, a non-single-crystal material). Examples of polycrystalline piezoelectric materials include: polycrystalline aluminum nitride, zinc oxide, and single-crystal lead zirconate titanate. Piezoelectric materials can also be rare earth element doped materials containing a certain atomic ratio of the above materials, such as 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.

[0073] The material of the top electrode (electrode pin or electrode connection edge) can be the same as that of the bottom electrode. Materials can include molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium, or composites or alloys of these metals. The top and bottom electrodes are generally made of the same material, but they can also be different.

[0074] The passivation layer can be made of silicon dioxide, aluminum nitride, silicon nitride, or other types of dielectric materials.

[0075] The following provides a detailed description of the specific structure and various possible implementations of the resonator, using specific examples:

[0076] Figure 1 This is a top view schematic diagram of the resonator provided in an embodiment of this application. Figure 2 yes Figure 1 A sectional view obtained by cutting along AO-A'. (See figure) Figure 1 and Figure 2As shown, the resonator 100 in this application specifically includes a substrate 1, a sandwich electrode 7, an acoustic mirror, a bottom electrode structure 3, a piezoelectric layer 4, and a top electrode 5. The substrate 1, sandwich electrode 7, acoustic mirror, bottom electrode structure 3, piezoelectric layer 4, and top electrode 5 are stacked sequentially, and the overlapping portion of the sandwich electrode 7, acoustic mirror, bottom electrode structure 3, piezoelectric layer 4, and top electrode 5 together forms the effective region of the resonator 100. Thus, the sandwich electrode 7 and the bottom electrode structure 3 together constitute the bottom electrode of the resonator. The bottom electrode and top electrode 5 can be used to connect the two terminals of the resonator 100 to other components in the circuit. The piezoelectric layer 4, located between the bottom electrode structure 3 and the top electrode 5, can convert electrical energy into sound wave energy through the inverse piezoelectric effect, and use the acoustic mirror to reflect the sound waves, thus forming resonance.

[0077] The sandwich electrode 7 and the bottom electrode structure 3 are interconnected and conductive, thus jointly forming the bottom electrode portion of the resonator 100. Furthermore, the sandwich electrode 7 can have various different structures and locations. For example, the sandwich electrode 7 can be disposed on the substrate 1, such as above the entire surface of the substrate 1, or within a cavity in the substrate 1.

[0078] As will be understood by those skilled in the art, in some embodiments, the resonator 100 may also include a passivation layer 6 or similar structures. The passivation layer 6 covers the top electrode 5, thereby protecting the top electrode 5 and similar structures.

[0079] In this embodiment of the resonator, the bottom electrode structure 3 is formed by stacking multiple layers. Specifically, the bottom electrode structure 3 includes a seed layer 31, a first bottom electrode layer 32, and a second bottom electrode layer 33. The first bottom electrode layer 32 is formed on the seed layer 31, and the second bottom electrode layer 33 is formed on and covers the first bottom electrode layer 32. The first bottom electrode layer 32 can be continuously formed on the seed layer 31.

[0080] In the bottom electrode structure 3, the first bottom electrode layer 32 and the second bottom electrode layer 33 are arranged adjacently and together constitute the bottom electrode film layer in the resonator 100. Therefore, the first bottom electrode layer 32 and the second bottom electrode layer 33 can jointly serve as the bottom electrode portion of the resonator 100. The seed layer 31 is stacked on the substrate 1 and the acoustic mirror, so that the first bottom electrode layer 32 grows or deposits on the seed layer 31 and forms a good crystal orientation under the induction of the seed layer 31. Since the bottom electrode structure 3 is divided into two layers, the first bottom electrode layer 32 and the second bottom electrode layer 33, the first bottom electrode layer 32 can be formed on the surface of the seed layer 31 after the seed layer 31 is formed, so as to protect the seed layer 31. Specifically, the first bottom electrode layer 32 directly wraps around the surface of the seed layer 31, thus forming a protective layer while serving as the bottom electrode portion. This protective layer isolates the seed layer 31 from the outer air, thereby preventing chemical reactions between the seed layer and the air.

[0081] The seed layer 31 and the first bottom electrode layer 32 can be formed continuously, that is, the seed layer 31 and the first bottom electrode layer 32 are formed continuously on the substrate 1 with an acoustic mirror in the same process or step; in this way, the surface of the seed layer 31 is exposed to air for a shorter time, which can better avoid the appearance of impurities on the surface of the seed layer.

[0082] Correspondingly, a second bottom electrode layer 33 is stacked on top of the first bottom electrode layer 32, and the second bottom electrode layer 33 covers the first bottom electrode layer 32. The second bottom electrode layer 33 and the top electrode 5 are disposed opposite each other, and together with the top electrode 5, they are used to realize the connection with the external circuit. Both the second bottom electrode layer 33 and the first bottom electrode layer 32 are formed of metallic material. Therefore, the second bottom electrode layer 33 can also be induced by the seed layer 31 during its formation, so that it forms a better vertical crystal orientation.

[0083] Based on this, since the first bottom electrode layer 32 and the second bottom electrode layer 33 have good perpendicular crystal orientation, the piezoelectric layer 4 grown on the second bottom electrode layer 33 can also form a good perpendicular crystal orientation, thereby improving the operating parameters of the entire resonator 100, such as the effective electromechanical coupling coefficient, series resonant impedance, parallel resonant impedance, and quality factor. Taking the effective electromechanical coupling coefficient as an example... Figure 3 This is a schematic diagram comparing the effective electromechanical coupling coefficient of the resonator in this embodiment and a conventional resonator. Please refer to... Figure 3 , Figure 3 The left side shows the effective electromechanical coupling coefficient Kt corresponding to the resonator in this embodiment, while the right side shows the effective electromechanical coupling coefficient Kt corresponding to a conventional resonator. Figure 3As can be seen from the embodiments of this application, since the first bottom electrode layer 32 and the seed layer 31 are formed continuously, and no impurities are formed on the surface of the seed layer 31 due to hydrolysis or other chemical reactions, it helps the first bottom electrode layer 32, the second bottom electrode layer 33 and the piezoelectric layer 4 grown on the second bottom electrode layer 33 to form a better crystal orientation, thereby having a higher effective electromechanical coupling coefficient Kt. In contrast, in existing resonators, since the bottom electrode and the seed layer 31 are not formed continuously, after the seed layer 31 is formed, since no protection is applied to the surface, impurities may form on the surface of the seed layer 31, affecting the vertical crystal orientation of the subsequent bottom electrode portion and the piezoelectric layer 4, resulting in a lower effective electromechanical coupling coefficient Kt.

[0084] Furthermore, it is understood that the resonator 100 in this application will also have a similar effect on parameters such as series resonant impedance, parallel resonant impedance and quality factor (Q value) as the effective electromechanical coupling coefficient Kt.

[0085] In existing resonators, the bottom electrode is responsible for external connections and conductivity, so the structure and fabrication process of the bottom electrode and the seed layer are usually not the same. In this application, the bottom electrode film of the resonator 100 is divided into two different film layers: a first bottom electrode layer 32 and a second bottom electrode layer 33. This allows the second bottom electrode layer 33 to handle the normal connections in the resonator 100's circuitry, while the first bottom electrode layer 32 shields and protects the surface of the seed layer 31, preventing chemical reactions and impurities from contacting the seed layer 31 with air. The shape and fabrication process of the first bottom electrode layer 32 can be adapted to the seed layer 31; for example, the first bottom electrode layer 32 and the seed layer 31 can be completed in the same process, thus facilitating the protection of the seed layer 31. The shape and fabrication process of the second bottom electrode layer 33 can be set according to the functional and structural requirements of the bottom electrode film itself to ensure normal connection and conduction with other conductive structures.

[0086] In some alternative embodiments, the first bottom electrode layer 32 and the seed layer 31 can be continuously deposited on a substrate 1 having an acoustic mirror, or having a sacrificial layer corresponding to the acoustic mirror. Specifically, the seed layer 31 and the first bottom electrode layer 32 can be sequentially deposited or grown on the substrate 1 having the acoustic mirror, and patterned by the same etching process to remove excess portions, thus continuously forming the seed layer 31 and the first bottom electrode layer 32 on the substrate 1.

[0087] In this method, the seed layer 31 and the first bottom electrode layer 32 are continuously formed on the substrate 1 with an acoustic mirror in the same etching process, instead of forming the seed layer 31 and the first bottom electrode layer 32 separately using multiple etching processes. Compared with the existing multiple etching processes in which the first film layer is deposited or generated and patterned, then the second film layer is deposited, and then patterned again, this method of continuously forming the seed layer 31 and the first bottom electrode layer 32 in the same process or step ensures that after the seed layer 31 is deposited, the first bottom electrode layer 32 continues to be deposited on the surface of the seed layer 31. This avoids the problem of external air coming into contact with the surface of the seed layer 31 and causing a chemical reaction when switching between different processes.

[0088] Continue to refer to Figure 2 Alternatively, the first bottom electrode layer 32 and the seed layer 31 can have the same shape. Specifically, the edges of the first bottom electrode layer 32 and the seed layer 31 are flush or nearly flush with each other in the longitudinal direction of the resonator. In this case, the surface of the seed layer 31, which serves as the growth basis for the first bottom electrode layer 32, will be completely covered by the first bottom electrode layer 32. Therefore, the entire seed layer 31 can be protected by the first bottom electrode layer 32, effectively preventing chemical reactions on the surface of the seed layer 31. At the same time, the bottom side of the first bottom electrode layer 32 is entirely covered by the seed layer 31, and the coverage area of ​​the seed layer 31 is relatively large, which allows the bottom electrode film layer and the piezoelectric layer 4 to form a better crystal orientation.

[0089] When a seed layer 31 exists beneath the first bottom electrode layer 32 and the second bottom electrode layer 33, the seed layer 31 itself may not be conductive, potentially affecting the conduction and connection of the entire bottom electrode. Therefore, as an alternative, the second bottom electrode layer 33 extends beyond the edge of the first bottom electrode layer 32 in the lateral direction of the resonator. Thus, the second bottom electrode layer 33 can extend beyond the boundary of the seed layer 31, facilitating conductive connection with other conductive structures, such as other electrode layers or leads.

[0090] It should be noted that since the second bottom electrode layer 33 only needs to maintain contact and conduction with other conductive structures, the second bottom electrode layer 33 can extend to the outer edge of the first bottom electrode layer 32 in the circumferential direction, or it can extend only from one direction in the lateral direction of the resonator 100 to the edge of the first bottom electrode layer 32, while in other directions, the edge of the second bottom electrode layer 33 remains flush with the edge of the first bottom electrode layer 32. The specific edge shape of the second bottom electrode layer 33 can be set according to the specific configuration and structural parameters of the resonator 100, and is not limited here.

[0091] Figure 4 yes Figure 2A magnified view of a portion at point B. Please refer to the diagram. Figure 2 and Figure 4 In some optional embodiments, the height of the portion of the second bottom electrode layer 33 covering the first bottom electrode layer 32 is higher than the height of the portion not covering the first bottom electrode layer 32, so that the second bottom electrode layer 33 has a stepped portion 331 at the position corresponding to the edge of the first bottom electrode layer 32. Specifically, each part of the second bottom electrode layer 33 has a relatively uniform thickness, and since the first bottom electrode layer 32 and the seed layer 31 occupy a certain height in the longitudinal direction of the resonator 100, when the second bottom electrode layer 33 covers the first bottom electrode layer 32 and other structures on the substrate 1, the height of each part of the second bottom electrode layer 33 will also change accordingly.

[0092] In this embodiment, a portion of the second bottom electrode layer 33 may cover the first bottom electrode layer 32, while another portion covers the substrate 1 or the acoustic mirror. The portion of the second bottom electrode layer 33 covering the first bottom electrode layer 32 has a higher height in the longitudinal direction of the resonator 100 than the portion of the second bottom electrode layer 33 covering the substrate 1 and the acoustic mirror. Due to the height difference between the two portions, a clearly defined step portion 331 is formed at the junction of these two portions, corresponding to the edge of the first bottom electrode layer 32.

[0093] Please refer to the details. Figure 4 The shape of the step portion 331 formed between the portion of the second bottom electrode layer 33 covering the first bottom electrode layer 32 and the portion not covering the first bottom electrode layer 32 will adapt to the edge shape of the first bottom electrode layer 32 in the transverse direction of the resonator 100. Obviously, the height of the step portion 331 in the longitudinal direction of the resonator 100 will match the thickness of the first bottom electrode layer 32, for example, the total height of the step portion 331 will be consistent with the sum of the thicknesses of the seed layer 31 and the first bottom electrode layer 32.

[0094] In some embodiments, since the first bottom electrode layer 32 in the bottom electrode structure 3 mainly serves to protect the seed layer 31, while the second bottom electrode layer 33 is mainly responsible for conductive connection, the thickness of the second bottom electrode layer 33 is greater than the thickness of the first bottom electrode layer 32, thereby providing more reliable conductivity.

[0095] It is understood that the first bottom electrode layer 32 and the second bottom electrode layer 33 can have various different thickness ratios along the longitudinal direction of the resonator 100. For example, in some embodiments, the thickness of the second bottom electrode layer 33 is less than the thickness of the first bottom electrode layer 32. In other embodiments, the thickness of the second bottom electrode layer 33 is equal to or approximately equal to the thickness of the first bottom electrode layer 32.

[0096] Alternatively, the thickness of the first bottom electrode layer 32 may be greater than or equal to and less than or equal to At this point, the first bottom electrode layer 32 has a suitable thickness, which can both ensure the protection of the seed layer 31 and effectively prevent chemical reactions such as hydrolysis of the seed layer 31, and not have too much impact on the overall thickness of the bottom electrode structure.

[0097] In some other alternative embodiments, the thickness of the first bottom electrode layer 32 may also be greater than or equal to... and less than or equal to It should be noted that the thickness of the first bottom electrode layer 32 can be adaptively adjusted according to the actual structure of the resonator or other requirements to meet different needs or structures.

[0098] To ensure good conductivity of the entire bottom electrode film and to facilitate the growth and bonding of the first bottom electrode layer 32 and the second bottom electrode layer 33, in some embodiments, both the first bottom electrode layer 32 and the second bottom electrode layer 33 are formed of metallic materials. For example, the material constituting the first bottom electrode layer 32 may include one or more of molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, and chromium; while the material constituting the second bottom electrode layer 33 may also include one or more of molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, and chromium.

[0099] The materials constituting the first bottom electrode layer 32 and the materials constituting the second bottom electrode layer 33 may be the same or different.

[0100] Specifically, in order to enable the second bottom electrode layer 33 to grow or deposit better on the first bottom electrode layer 32, in some optional embodiments, the second bottom electrode layer 33 and the first bottom electrode layer 32 can be made of the same material, for example, the first bottom electrode layer 32 and the second bottom electrode layer 33 can both be made of the same metal.

[0101] It should be noted that even if the second bottom electrode layer 33 and the first bottom electrode layer 32 are made of the same material, in some resonator structures, such as those where the acoustic mirror is located above the surface of the substrate 1, the structure of the acoustic mirror can affect structures such as the seed layer 31 in the bottom electrode structure. Therefore, the second bottom electrode layer 33 may still exhibit a stepped structure at the edge corresponding to the first bottom electrode layer 32. In this case, when observing the cross-section of the resonator, it can still be observed that the second bottom electrode layer 33 forms a stepped section with a clear boundary or other abrupt shape structure at the position corresponding to the edge of the first bottom electrode layer 32.

[0102] On the other hand, the second bottom electrode layer 33 and the first bottom electrode layer 32 can also be made of different materials. For example, the first bottom electrode layer 32 can be made of a material that is more suitable for growth or deposition on the seed layer 31, while the second bottom electrode layer 33 can be made of a material with better conductivity or that is more suitable for setting the piezoelectric layer 4.

[0103] Furthermore, the acoustic mirror of the resonator can take different forms and have different structures. For example, the acoustic mirror may include an air cavity, a Bragg reflector, or other acoustic mirrors with different structures. In this embodiment, for ease of description, the acoustic mirror is described as mainly composed of an air cavity 2. For details, please refer to [link to documentation]. Figure 2 As shown.

[0104] In addition, it should be noted that, in Figures 2 to 4 In the provided resonator implementation structure, the acoustic mirror, i.e., the air cavity 2, is located above the upper surface of the substrate 1. Specifically, as follows... Figure 2 As shown, at this time, the sandwich electrode 7 and the bottom electrode structure 3 together surround the outside of the air cavity 2.

[0105] Specifically, the bottom electrode structure 3, specifically the seed layer 31 within it, together with the sandwich electrode 7, forms the air cavity 2. Since the air cavity 2 is located outside the substrate 1, i.e., protruding from the outer side of the substrate 1, the shape of the seed layer 31 is determined by the structure and characteristics of the air cavity 2. Specifically, different portions of the seed layer 31 in the transverse direction of the resonator 100 will have different longitudinal heights.

[0106] Correspondingly, the shapes of other layers in the bottom electrode structure 3, such as the first bottom electrode layer 32, will also adapt to the outline of the seed layer 31. That is, the shapes of the seed layer 31 and the first bottom electrode layer 32 are determined by the structure and characteristics of the air cavity 2.

[0107] Similar to the first bottom electrode layer 32 or the second bottom electrode layer 33, the material constituting the sandwich electrode 7 includes at least one of molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, and chromium. This similar material composition of the sandwich electrode 7 and the bottom electrode structure (mainly the second bottom electrode layer 33) results in better conductivity and facilitates the growth of structures such as the second bottom electrode layer 33.

[0108] It should be noted that the air cavity 2 can be formed by setting a sacrificial layer, specifically by etching or other methods. In order to form the pattern of the sacrificial layer on the sandwich electrode 7 by etching, the resonator also includes an etch barrier layer 8. The etch barrier layer 8 is set on the sandwich electrode 7. After the sacrificial layer is etched, the etch barrier layer 8 will be patterned together for subsequent etching of each layer.

[0109] Those skilled in the art will understand that in the process of forming the air cavity 2 using the sacrificial layer, after the sacrificial layer is subsequently removed, the etching barrier layer 8 is located inside the air cavity 2, specifically at the bottom wall of the air cavity 2 in the longitudinal direction of the resonator 100.

[0110] Figure 5 This is a schematic diagram of another resonator structure provided in an embodiment of this application. For example... Figure 5 As shown, in another resonator implementation structure, the resonator 200 sequentially includes a substrate 1, an acoustic mirror, a bottom electrode structure 3', a piezoelectric layer 4, a top electrode 5, and a passivation layer 6. The substrate 1, acoustic mirror, bottom electrode structure 3', piezoelectric layer 4, top electrode 5, and passivation layer 6 are stacked sequentially, and the overlapping portions of the acoustic mirror, bottom electrode structure 3', piezoelectric layer 4, and top electrode 5 together form the effective region of the resonator 200. The bottom electrode structure 3 has... Figure 2 A similar structure to the illustrated embodiment specifically includes a seed layer 31', a first bottom electrode layer 32', and a second bottom electrode layer 33'. The seed layer 31' and the first bottom electrode layer 32' are formed continuously, and the second bottom electrode layer 33' is formed on and covers the first bottom electrode layer 32'. Unlike the previous embodiment, in this embodiment, the air cavity 2' in the resonator 200 is disposed on the substrate 1, and the sandwich electrode 7 is omitted. Therefore, the bottom electrode structure 3' mainly functions as the bottom electrode. At this time, a recess with a specific concave shape can be formed on the surface of the substrate 1 by etching or other methods, and a sacrificial layer is disposed within the recess. The bottom electrode structure 3' and other film structures in the resonator 200 are then deposited or grown sequentially. After the sacrificial layer is removed, the air cavity 2' is formed within the recess of the substrate 1.

[0111] At this point, the seed layer 31' and the first bottom electrode layer 32' in the bottom electrode structure 3' are relatively flat. And generally speaking, the second bottom electrode layer 33' does not form a stepped portion at the edge corresponding to the first bottom electrode layer 32'.

[0112] In this embodiment, the resonator specifically includes a substrate, a sandwich electrode, an acoustic mirror, a bottom electrode structure, a piezoelectric layer, a top electrode, and a passivation layer. The substrate, sandwich electrode, acoustic mirror, bottom electrode structure, piezoelectric layer, top electrode, and passivation layer are sequentially stacked, and the overlapping portions of the sandwich electrode, acoustic mirror, bottom electrode structure, piezoelectric layer, and top electrode together form the effective region of the resonator. The bottom electrode structure and the sandwich electrode together surround the acoustic mirror, and the sandwich electrode and bottom electrode structure are interconnected and conductive. The bottom electrode structure includes a seed layer, a first bottom electrode layer, and a second bottom electrode layer. The first bottom electrode layer is disposed on the seed layer, and the second bottom electrode layer is formed on the first bottom electrode layer and covers the first bottom electrode layer. The first bottom electrode layer directly wraps around the surface of the seed layer, thus forming a protective layer. This protective layer isolates the seed layer from the outer air, thereby preventing chemical reactions on the seed layer surface and allowing the piezoelectric layer and other film layers to form a better perpendicular crystal orientation, resulting in better resonator performance.

[0113] This application also provides a method for manufacturing a resonator. The method for manufacturing a resonator provided in this application is capable of manufacturing the resonator in the foregoing embodiments. Figure 6 This is a schematic diagram illustrating the steps of the resonator manufacturing method provided in this application. Figure 6 As shown, the resonator manufacturing method provided in this embodiment specifically includes the following steps:

[0114] S101, Provide substrate.

[0115] Specifically, the materials constituting the substrate include one of the following: single-crystal silicon, gallium nitride, gallium arsenide, sapphire, quartz, silicon carbide, diamond, or single-crystal piezoelectric substrates such as lithium niobate, lithium tantalate, or potassium niobate.

[0116] Figure 7 According to Figure 6 A schematic diagram of the resonator structure after step S101, corresponding to the resonator manufacturing method. (See attached diagram.) Figure 7 As shown, the substrate 1 of the resonator is relatively flat overall, so that other stacked structures can be set on the substrate 1.

[0117] S102. Form a sandwich electrode on the substrate, and form an acoustic mirror or a sacrificial layer corresponding to the acoustic mirror on the sandwich electrode.

[0118] When forming the sandwich electrode 7 on the substrate 1, the sandwich electrode 7 may have a variety of different structures and positions, as described in the relevant descriptions of the foregoing embodiments.

[0119] Acoustic mirrors can have a variety of different configurations and structures, such as Bragg reflectors or air cavities. Figure 8 According to Figure 6A schematic diagram of the resonator structure after step S102, corresponding to the resonator manufacturing method. In this embodiment, an air cavity is used as the acoustic mirror for illustration. The air cavity has a relatively simple structure and a relatively simple manufacturing process.

[0120] When forming an acoustic mirror on substrate 1, the main process involves depositing a sacrificial layer material inside, on the upper surface of, or in other layered structures of substrate 1 to form a sacrificial layer 21. After forming other film structures on the sacrificial layer 21, the sacrificial layer 21 is removed to create an air cavity. The deposition processes for the sacrificial layer material mainly include sputtering, chemical vapor deposition (CVD), physical vapor deposition (PVD), or spin coating.

[0121] It should be noted that, depending on the specific location and structure of the acoustic mirror, the steps for forming the acoustic mirror on the substrate 1 can have various different specific processes. In this embodiment, the air cavity is formed above the upper surface of the substrate 1. Therefore, in order to form the air cavity 2, it is necessary to set up structures such as the sandwich electrode 7, and to place the sacrificial layer 21 for preparing the air cavity on the sandwich electrode 7.

[0122] In some alternative embodiments, the air cavity in the resonator is disposed inside the substrate 1, and the sacrificial layer forming the air cavity 2 and the substrate 1 are planarized. In this case, a recess can be directly formed on the substrate 1 by etching or other methods, and the sacrificial layer material is deposited in the recess. Then, the sacrificial layer material is chemically or mechanically polished until the surface of the sacrificial layer is flush with the upper surface of the substrate 1. After other films are deposited on the upper surface of the substrate 1, the sacrificial layer is removed, thereby forming a hollow cavity, i.e., air cavity 2', in the recess that was originally filled with sacrificial layer material. When forming the recess on the substrate 1, the shape of the recess matches the desired shape of the air cavity.

[0123] S103. A seed layer and a first bottom electrode layer are continuously formed on a substrate having an acoustic mirror or a sacrificial layer.

[0124] Figure 9 According to Figure 6 A schematic diagram of the resonator structure after step S103, corresponding to the resonator manufacturing method. (See attached diagram.) Figure 9 As shown, specifically, after forming an acoustic mirror or a sacrificial layer corresponding to the acoustic mirror on the substrate 1, other film structures can be formed on the substrate 1 with the acoustic mirror or the sacrificial layer. In this embodiment, the acoustic mirror is an air cavity as an example. Specifically, a seed layer 31 and a first bottom electrode layer 32 are sequentially deposited or grown on the substrate 1 with the sacrificial layer 21, and then patterned through the same etching process to remove excess parts. In this way, the seed layer 31 and the first bottom electrode layer 32 can be continuously formed on the substrate 1.

[0125] Since the seed layer 31 and the first bottom electrode layer 32 are formed continuously in the same etching process, they will have the same boundary shape in the lateral direction of the resonator. Therefore, the first bottom electrode layer 32 can completely cover the upper surface of the seed layer 31 and protect the surface of the seed layer 31, preventing hydrolysis or other chemical reactions from occurring due to contact between the surface of the seed layer 31 and the air. This protective effect of the first bottom electrode layer 32 effectively prevents the formation of impurities on the surface of the seed layer 31, which is beneficial for the formation of good crystal orientation of the first bottom electrode layer 32, the second bottom electrode layer 33, and the piezoelectric layer 4, ensuring the working performance of the resonator.

[0126] Similar to the formation of other films, the continuous formation of the seed layer 31 and the first bottom electrode layer 32 can primarily be achieved through a deposition process. Specifically, in one optional formation method, the seed layer 31 and the first bottom electrode layer 32 can be continuously deposited and patterned on a substrate 1 with an acoustic mirror (currently filled by the sacrificial layer 21 structure). Since the seed layer 31 and the first bottom electrode layer 32 are patterned using an etching process only after continuous deposition, the surface of the seed layer 31 is not exposed to air for a long time, thus preventing the formation of surface impurities and effectively ensuring the perpendicular crystal orientation during subsequent film formation.

[0127] It is understandable that the deposition processes of the seed layer 31 and the first bottom electrode layer 32 mainly include sputtering, chemical vapor deposition (CVD), physical vapor deposition (PVD), or spin coating.

[0128] S104. A second bottom electrode layer is formed on the first bottom electrode layer.

[0129] Figure 10 According to Figure 6 A schematic diagram of the resonator structure after step S104, according to the resonator manufacturing method. Please refer to... Figure 10 After the first bottom electrode layer 32 is formed, a second bottom electrode layer 33 can be formed above it. Alternatively, the second bottom electrode layer 33 can be formed above the first bottom electrode layer 32 by deposition or other means. Specifically, the second bottom electrode layer 33 can be deposited on the first bottom electrode layer 32, covering it. Therefore, the second bottom electrode layer 33 and the first bottom electrode layer 32 remain in contact, and the second bottom electrode layer 33 can extend to the connection terminals of the resonator or other conductive structures, thereby maintaining contact and conduction with these conductive structures.

[0130] It is understood that the material forming the second bottom electrode layer 33 can be the same as or different from the material of the first bottom electrode layer 32. For example, the first bottom electrode layer 32 and the second bottom electrode layer 33 can be made of the same metallic material.

[0131] It is understandable that the deposition process for the second bottom electrode layer 33 mainly includes sputtering, chemical vapor deposition (CVD), physical vapor deposition (PVD), or spin coating.

[0132] S105. A piezoelectric layer and a top electrode are formed sequentially on the second bottom electrode layer.

[0133] Figure 11 According to Figure 6 A schematic diagram of the structure of the resonator after step S105, corresponding to the resonator manufacturing method. Figure 12 According to Figure 6 A schematic diagram of the resonator structure after step S105, corresponding to the resonator manufacturing method, showing the formation of the top electrode. Please refer to... Figures 11 to 12 After the second bottom electrode layer 33 is formed, the seed layer 31, the first bottom electrode layer 32 and the second bottom electrode layer 33 together form the bottom electrode structure 3. The piezoelectric layer 4 and the top electrode 5 can be formed sequentially on the bottom electrode structure 3 by means of deposition or other methods. Figure 13 According to Figure 6 A schematic diagram of the resonator structure corresponding to the resonator manufacturing method, showing the top electrode with a passivation layer formed after step S105. Figure 13 In the resonator structure shown, a passivation layer 6 covers the top electrode 5. The top electrode 5 and the passivation layer 6 can be formed in the same etching process. Figures 11-13 The structure, function, and composition of the piezoelectric layer 4, top electrode 5, and passivation layer 6 in the resonator structure shown have been specifically described in the foregoing embodiments and will not be repeated here.

[0134] It should be noted that in this embodiment, after the piezoelectric layer 4 and the top electrode 5 are formed on the second bottom electrode layer, the sacrificial layer 21 can be released, thereby forming the air cavity 2, as shown below. Figure 12 and Figure 13 As shown. This air cavity 2 can serve as an acoustic mirror in the resonator.

[0135] In one alternative implementation, the air cavity 2 or the acoustic mirror is formed on other structures. Figure 14 This is a schematic diagram illustrating the specific steps of forming a sandwich electrode on a substrate and forming an acoustic mirror or a sacrificial layer corresponding to the acoustic mirror on the sandwich electrode, as provided in an embodiment of this application. Please refer to... Figure 14 The step of forming an acoustic mirror on substrate 1 may specifically include:

[0136] S201, Form a sandwich electrode on substrate 1.

[0137] Figure 15 This is a schematic diagram of the resonator structure corresponding to step S201 in the resonator fabrication method provided in this application embodiment. For example... Figure 15 As shown, the sandwich electrode 7 can be formed on the upper surface of the substrate 1 by means of deposition or other methods. The sandwich electrode 7 extends laterally along the resonator and is connected to the connection terminal of the resonator or other conductive structures.

[0138] S202, Deposit etching barrier layer and sacrificial layer materials on the sandwich electrode.

[0139] Since the size and shape of the acoustic mirror in the transverse direction of the resonator are different from those of the sandwich electrode 7, the acoustic mirror needs to be patterned by means of etching. Figure 16 This is a schematic diagram of the resonator structure corresponding to step S202 in the resonator fabrication method provided in this application embodiment. Please refer to... Figure 16 Specifically, an etch barrier layer 8 and a sacrificial layer material are formed on the upper surface of the sandwich electrode 7. The etch barrier layer 8 and the sacrificial layer material can be deposited continuously. The material used to fabricate the sacrificial layer 21 may include polysilicon, silicon oxide, and metals.

[0140] S203, patterned etch barrier layer and sacrificial layer materials to form a sacrificial layer on the etch barrier layer, the sacrificial layer being used to form an air cavity after being removed.

[0141] Figure 17 This is a schematic diagram of the resonator structure corresponding to step S203 in the resonator fabrication method provided in this application embodiment. For details, please refer to... Figure 17 After depositing the etch stop layer and sacrificial layer materials, an etching process is needed to pattern the etch stop layer and sacrificial layer materials, thereby forming the sacrificial layer 21 on the etch stop layer 8. The shapes of the etch stop layer 8 and the sacrificial layer 21 match the air cavity 2 to be formed. Specifically, the etch stop layer 8 and the sacrificial layer 21 can be etched out in a single etching process. After the sacrificial layer 21 is removed in a subsequent process, the air cavity 2 is obtained.

[0142] Figure 18 This is a schematic diagram illustrating another specific step in forming a sandwich electrode on a substrate and forming an acoustic mirror or a sacrificial layer corresponding to the acoustic mirror on the sandwich electrode, as provided in an embodiment of this application. Please refer to... Figure 18 , Figure 18 The method for fabricating the resonator shown includes, in addition to Figure 14In addition to steps S201 to S203, the subsequent processing of the sacrificial layer is also described. Specifically, after the seed layer 31 and the first bottom electrode layer 32 are continuously formed on the substrate 1 with the acoustic mirror, the sacrificial layer can be set according to steps S201 to S203. The specific steps are described above. Figure 14 Following step S204, the method for fabricating the resonator further includes:

[0143] S204. Remove the sacrificial layer to form an air cavity.

[0144] Specifically, the material of the sacrificial layer 21 can be removed through a venting channel or an etching process. Etching processes include ion etching or wet etching. After the sacrificial layer 21 is removed, a cavity structure is formed, which is the air cavity 2 used as an acoustic mirror.

[0145] In this embodiment, the resonator manufacturing method includes first providing a substrate, forming a sandwich electrode on the substrate, and forming an acoustic mirror or sacrificial layer on the sandwich electrode; then, continuously forming a seed layer and a first bottom electrode layer on the substrate with the acoustic mirror, and then forming a second bottom electrode layer on the first bottom electrode layer; subsequently, forming a piezoelectric layer, a top electrode, and a passivation layer sequentially on the second bottom electrode layer. The first bottom electrode layer of the resonator directly wraps around the surface of the seed layer, thus forming a protective layer. This protective layer isolates the seed layer from the air in the outer layer, thereby preventing chemical reactions on the surface of the seed layer. The piezoelectric layer and other films form a better perpendicular crystal orientation, allowing the resonator to have better operating performance.

[0146] As those skilled in the art will understand, the resonator according to the present invention can be used to form a filter or electronic device. In addition to the resonator in the above embodiments, the filter may also include other basic elements coupled or disposed therein. Specifically, the specific structure, function, and main working principle of the resonator in the filter and electronic device have been described in detail in the foregoing embodiments, and will not be repeated here.

[0147] The electronic devices mentioned here include, but are not limited to, intermediate products such as radio frequency front-ends and filtering and amplification modules, as well as terminal products such as mobile phones, WIFI, and drones.

[0148] In this invention, "upper" and "lower" are relative to the bottom surface of the substrate of the resonator. 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.

[0149] In this invention, "inner" and "outer" refer to the center of the effective region of the resonator in the lateral or radial direction. The side or end of a component closer to the center is called the inner side or inner end, while the side or end of the component farther from the center is called the outer side or outer end. For a reference position, being inside the position means being between that position and the center in the lateral or radial direction, while being outside the position means being farther from the center in the lateral or radial direction.

[0150] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection through an intermediate medium, or a connection within two components or an interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0151] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and 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. Therefore, they should not be construed as limitations on this invention.

[0152] The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein.

[0153] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such that a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or apparatus.

[0154] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A resonator, characterized in that, include Substrate; Sandwich electrode; Acoustic mirror; The bottom electrode structure and the sandwich electrode together surround the outside of the acoustic mirror. The sandwich electrode and the bottom electrode structure are interconnected and conductive. The bottom electrode structure includes a seed layer, a first bottom electrode layer and a second bottom electrode layer. The first bottom electrode layer is disposed on the seed layer, and the second bottom electrode layer is formed on the first bottom electrode layer and covers the first bottom electrode layer. piezoelectric layer, and Top electrode; The overlapping portion of the sandwich electrode, the acoustic mirror, the bottom electrode structure, the piezoelectric layer, and the top electrode together forms the effective region of the resonator. The first bottom electrode layer is continuously formed on the seed layer, and the first bottom electrode layer and the seed layer are continuously deposited, and the first bottom electrode layer and the seed layer have the same shape.

2. The resonator according to claim 1, characterized in that, In the lateral direction of the resonator, the second bottom electrode layer extends to the outside of the edge of the first bottom electrode layer.

3. The resonator according to claim 2, characterized in that, The portion of the second bottom electrode layer that covers the first bottom electrode layer is higher than the portion that does not cover the first bottom electrode layer, so that the second bottom electrode layer has a stepped portion at the position corresponding to the edge of the first bottom electrode layer.

4. The resonator according to claim 1, characterized in that, The thickness of the second bottom electrode layer is greater than the thickness of the first bottom electrode layer.

5. The resonator according to claim 1, characterized in that, The thickness of the first bottom electrode layer is greater than or equal to 300 Å and less than or equal to 600 Å.

6. The resonator according to claim 1, characterized in that, The seed layer is made of at least one of aluminum nitride, zinc oxide, and lead zirconate titanate.

7. The resonator according to claim 1, characterized in that, The material of the first bottom electrode layer includes at least one of molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, and chromium; and / or, The material of the second bottom electrode layer includes at least one of molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, and chromium.

8. The resonator according to claim 1, characterized in that, The sandwich electrode is disposed on the substrate.

9. The resonator according to claim 1, characterized in that, The acoustic mirror includes a Bragg reflector or an air cavity.

10. The resonator according to claim 9, characterized in that, The acoustic mirror includes the air cavity, and the sandwich electrode and the bottom electrode structure together surround the outside of the air cavity.

11. The resonator according to claim 10, characterized in that, The materials of the sandwich electrode include at least one of molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, and chromium.

12. The resonator according to claim 9, characterized in that, It also includes an etch barrier layer disposed on the sandwich electrode.

13. The resonator according to claim 12, characterized in that, The etching barrier layer is located inside the air cavity.

14. The resonator according to claim 1, characterized in that, It also includes a passivation layer that covers the top electrode.

15. A filter, characterized in that, Includes the resonator according to any one of claims 1-14.

16. An electronic device, characterized in that, Includes the filter as described in claim 15.

17. A method for manufacturing a resonator, characterized in that, include: Provide substrate; A sandwich electrode is formed on the substrate, and an acoustic mirror or a sacrificial layer corresponding to the acoustic mirror is formed on the sandwich electrode; A seed layer and a first bottom electrode layer are continuously formed on the substrate having the acoustic mirror or the sacrificial layer; A second bottom electrode layer is formed on the first bottom electrode layer; A piezoelectric layer and a top electrode are sequentially formed on the second bottom electrode layer.

18. The manufacturing method according to claim 17, characterized in that, The continuous formation of the seed layer and the first bottom electrode layer specifically includes: The seed layer and the first bottom electrode layer are sequentially deposited and patterned on the substrate having the acoustic mirror or the sacrificial layer.

19. The manufacturing method according to claim 17, characterized in that, The process of forming a second bottom electrode layer on the first bottom electrode layer specifically includes: A second bottom electrode layer is deposited and patterned on the first bottom electrode layer, wherein the second bottom electrode layer covers the first bottom electrode layer.

20. The manufacturing method according to any one of claims 17-19, characterized in that, The acoustic mirror is an air cavity; The step of forming a sandwich electrode on the substrate and forming an acoustic mirror or a sacrificial layer corresponding to the acoustic mirror on the sandwich electrode specifically includes: A sandwich electrode is formed on the substrate; An etching barrier layer and a sacrificial layer material are deposited on the sandwich electrode; The etching barrier layer and the sacrificial layer material are patterned to form a sacrificial layer on the etching barrier layer, the sacrificial layer being used to form the air cavity after being removed.

21. The manufacturing method according to claim 20, characterized in that, After continuously forming a seed layer and a first bottom electrode layer on the substrate having the acoustic mirror or the sacrificial layer, the method further includes: The sacrificial layer is removed to form the air cavity.

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