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

Abstract

This invention provides a resonator array, a filter, an electronic device, and a method for fabricating a resonator. The method includes: providing a substrate; forming a stacked structure on the substrate consisting of an acoustic mirror, a bottom electrode, a piezoelectric layer, a top electrode, and a conductive layer, wherein the conductive layer covers a portion of the top electrode; forming a lead opening structure on the stacked structure through a single patterning step, the lead opening structure including a first opening extending at least to the conductive layer and a second opening extending to the bottom electrode; forming a top electrode lead accommodated within the first opening and a bottom electrode lead accommodated within the bottom electrode opening. This invention can reduce the fabrication cost of resonators.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a resonator array, filter, electronic device, and method for manufacturing a 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] Existing resonators include a substrate and acoustic mirrors, a lower electrode, a piezoelectric layer, and an upper electrode, which are sequentially stacked on the substrate. For the connection between the upper and lower electrodes and external components, a lead groove for the upper electrode can be formed by etching the dielectric layer on the surface of the upper electrode, and a lead groove for the lower electrode can be formed by etching the piezoelectric layer on the surface of the lower electrode. This forms a lead structure that can be accommodated in either the upper or lower electrode lead groove, thus enabling the connection between the upper and lower electrodes in different resonators, i.e., connecting the upper electrode in one resonator to the lower electrode in another. Typically, the thickness of the piezoelectric layer is greater than the thickness of the dielectric layer on the surface of the upper electrode. To avoid over-etching the upper electrode at the location of the upper electrode lead groove, the etching of the dielectric layer on the surface of the upper electrode and the etching of the piezoelectric layer on the surface of the lower electrode are generally not performed in the same etching process.

[0004] However, the existing resonator manufacturing methods mentioned above require etching the upper electrode lead groove and the lower electrode lead groove in two different etching processes, which results in a high cost for resonator manufacturing. Summary of the Invention

[0005] In view of the above problems, this application provides a resonator group, a filter, an electronic device, and a method for manufacturing a resonator, which can complete the lead opening structure in the same process, thereby reducing the manufacturing cost of the resonator.

[0006] To achieve the above objectives, the first aspect of this application provides a method for manufacturing a resonator, comprising:

[0007] Provide substrate;

[0008] A stacked structure consisting of an acoustic mirror, a bottom electrode, a piezoelectric layer, a top electrode, and a conductive layer is formed on a substrate, wherein the conductive layer covers a portion of the top electrode.

[0009] A lead opening structure is formed on the stacked structure by a single patterning process. The lead opening structure includes a first opening extending to at least the conductive layer and a second opening extending to the bottom electrode.

[0010] A top electrode lead is formed and housed in the first opening, and a bottom electrode lead is formed and housed in the bottom electrode opening.

[0011] In one alternative implementation, a lead opening structure is patterned on the stacked structure, specifically including:

[0012] The first and second openings are patterned separately using the same etching process.

[0013] In one optional implementation, the first opening and the second opening are patterned in the same etching process, specifically including:

[0014] A second opening is patterned in the edge region of the bottom electrode so that the second opening penetrates the piezoelectric layer and extends to the bottom electrode, wherein the edge region of the bottom electrode is the part of the bottom electrode that is not covered by the top electrode;

[0015] The first opening is patterned on the conductive layer.

[0016] In one alternative embodiment, the second opening extends to the side surface of the bottom electrode facing the top electrode; or

[0017] The second opening extends to the bottom electrode in the longitudinal region of the resonator.

[0018] In one alternative implementation, the first opening extends to the conductive layer or the top electrode.

[0019] In one alternative embodiment, the first opening extends to the surface of the conductive layer; or the first opening extends to the inner region of the conductive layer in the longitudinal direction of the resonator; or the first opening extends to the surface of the top electrode; or the first opening extends to the inner region of the top electrode in the longitudinal direction of the resonator.

[0020] In one optional implementation, a lead layer is provided on the lead opening structure, and the lead layer is patterned, specifically including:

[0021] A lead layer is provided on the laminated structure;

[0022] The lead layer is patterned to form leads at positions corresponding to the lead opening structure. The portion of the lead housed in the first opening forms the top electrode lead, and the portion of the lead housed in the second opening forms the bottom electrode lead.

[0023] In one alternative implementation, a lead opening structure is patterned on the stacked structure, specifically including:

[0024] The first and second openings are patterned and interconnected in the same etching process.

[0025] A second aspect of this application provides a resonator array, including at least two resonator units and leads for connecting adjacent resonator units; each resonator unit includes an acoustic mirror, a bottom electrode, a piezoelectric layer, a top electrode, and a conductive layer stacked together, the overlapping portion of the acoustic mirror, bottom electrode, piezoelectric layer, and top electrode together forming the effective region of the resonator unit; the conductive layer covers at least a portion of the edge region of the top electrode, and the conductive layer and the top electrode are electrically connected;

[0026] At least two resonator units include a first resonator unit and a second resonator unit. The first resonator unit has a first opening extending at least to the conductive layer, and the second resonator unit has a second opening extending to the bottom electrode. The first opening and the second opening are formed in the same patterning process.

[0027] The leads include a top electrode lead housed in a first opening and a bottom electrode lead housed in a second opening.

[0028] In one alternative implementation, the first opening extends to the conductive layer or the top electrode.

[0029] In one alternative implementation, the first opening extends to the surface of the conductive layer; or the first opening extends to the inner region of the conductive layer in the longitudinal direction of the resonator; or the first opening extends to the surface of the top electrode; or the first opening extends to the inner region of the top electrode in the longitudinal direction of the resonator.

[0030] In one alternative implementation, the second opening penetrates the piezoelectric layer.

[0031] In one alternative implementation, the second opening extends to the side surface of the bottom electrode facing the top electrode.

[0032] In one alternative implementation, the second opening extends into the inner region of the bottom electrode in the longitudinal direction of the resonator unit.

[0033] In one alternative implementation, the thickness of the conductive layer in the longitudinal direction of the resonator unit is greater than or equal to the thickness of the piezoelectric layer in that direction.

[0034] In one alternative implementation, both the first opening and the second opening are located outside the effective area.

[0035] In one alternative embodiment, the conductive layer has a suspended portion, and a suspended gap exists between the suspended portion and the top electrode.

[0036] In one optional embodiment, a conductive layer surface dielectric layer is further included, which is stacked on the side of the conductive layer opposite to the top electrode; the first opening penetrates the conductive layer surface dielectric layer.

[0037] In one alternative implementation, the first opening and the second opening have overlapping portions in the transverse direction of the resonator unit.

[0038] In one alternative embodiment, the lead material includes at least one of molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, and chromium.

[0039] A third aspect of this application provides a filter including the aforementioned resonator array.

[0040] A fourth aspect of this application provides an electronic device including the filter described above.

[0041] In this embodiment of the application, the resonator fabrication method includes: providing a substrate; forming a stacked structure on the substrate consisting of an acoustic mirror, a bottom electrode, a piezoelectric layer, a top electrode, and a conductive layer, wherein the conductive layer covers a portion of the top electrode; forming a lead opening structure on the stacked structure by a single patterning step, the lead opening structure including a first opening extending at least to the conductive layer and a second opening extending to the bottom electrode; forming a top electrode lead accommodated in the first opening and a bottom electrode lead accommodated in the bottom electrode opening.

[0042] In the above scheme, forming a top electrode lead housed in the first opening allows the conductive layer, i.e., the top electrode, to be led out and electrically connected to a predetermined bottom electrode lead; forming a bottom electrode lead housed in the second opening allows the bottom electrode to be led out and connected to the predetermined top electrode lead. Thus, by connecting the conductive layer of one resonator unit to the bottom electrode of another resonator unit, the top electrode of one resonator unit can be connected to the bottom electrode of another resonator unit. Furthermore, this application forms the lead opening structure in a single patterning operation on the stacked structure. The first and second openings are formed in the same patterning process. On the one hand, this saves etching steps and reduces the manufacturing cost of the resonator. On the other hand, even if the etching depth is designed to be large in order to completely etch through the piezoelectric layer, the thickness of the conductive layer acts as an etching buffer in the first opening. The patterning operation extends into the conductive layer or partially to the top electrode without etching through it. The top electrode lead can make good contact with the conductive layer in the first opening, resulting in low contact resistance and thus improving the device performance of the resonator.

[0043] 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

[0044] Figure 1 This is a schematic diagram of the structure of a resonator array in the prior art;

[0045] Figure 2This is a schematic diagram of a resonator with leads connected to it in the prior art.

[0046] Figure 3a This is a schematic diagram of the structure of a resonator array provided in an embodiment of this application;

[0047] Figure 3b A schematic diagram of another resonator array structure provided in an embodiment of this application;

[0048] Figure 4 A schematic flowchart illustrating the resonator fabrication method provided in an embodiment of this application;

[0049] Figure 5 A schematic diagram of the resonator structure after step S10, corresponding to the resonator fabrication method provided in the embodiments of this application;

[0050] Figure 6 A schematic diagram of the resonator structure after step S20, corresponding to the resonator fabrication method provided in the embodiments of this application;

[0051] Figure 7 A schematic diagram of the resonator structure after step S30, corresponding to the resonator fabrication method provided in the embodiments of this application;

[0052] Figure 8 A schematic diagram of the resonator structure after step S40, corresponding to the resonator fabrication method provided in the embodiments of this application;

[0053] Figure 9 This is a schematic diagram of another structure of the resonator after step S40, corresponding to the resonator fabrication method provided in the embodiments of this application.

[0054] Explanation of reference numerals in the attached figures:

[0055] 200 - Resonator; 100, 100' - Resonator group; 10 - Resonator unit; 101, 202 - Acoustic mirror; 102 - Bottom electrode; 103, 204 - Piezoelectric layer; 104, 104' - Top electrode; 105 - Conductive layer; 106 - Conductive layer surface dielectric layer; 107, 201 - Substrate; 108, 109 - Gap; 110 - Suspended portion; 11 - First resonator unit; 111, 111' - First opening; 12 - Second resonator unit; 121, 121' - Second opening; 20, 20' - Leads; 21 - Top electrode lead; 22 - Bottom electrode lead; 203 - Lower electrode; 205 - Upper electrode; 206 - Upper electrode surface dielectric layer; 207 - Upper electrode lead groove; 208 - Lower electrode lead groove; 209 - Lead structure. Detailed Implementation

[0056] 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.

[0057] Resonators are common electronic devices used in filtering systems such as filters. Current resonators can include types such as thin-film bulk acoustic wave (TIW) resonators. Taking the commonly used thin-film bulk acoustic wave (TIW) resonator as an example, it is specifically formed by a multi-layered stacked structure.

[0058] Reference Figure 1 , Figure 2 The existing resonator 200 includes a substrate 201 and films such as an acoustic mirror 202, a lower electrode 203, a piezoelectric layer 204, an upper electrode 205, and a dielectric layer 206 on the surface of the upper electrode, stacked on the substrate 201. To connect the upper electrode 205 and the lower electrode 203 to the outside world, an upper electrode lead groove 207 is formed by etching the dielectric layer 206 on the surface of the upper electrode, and a lower electrode lead groove 208 is formed by etching the piezoelectric layer 204 on the surface of the lower electrode 203. A lead structure 209 is then formed that simultaneously covers both the upper electrode lead groove 207 and the lower electrode lead groove 208, thereby achieving the connection between the upper electrode 205 and the lower electrode 203.

[0059] In the prior art, the etching of the dielectric layer 206 on the surface of the upper electrode and the etching of the piezoelectric layer 204 on the surface of the lower electrode 203 are generally not completed in the same etching process. This is because, under normal circumstances, the thickness of the piezoelectric layer 204 is greater than the thickness of the dielectric layer 206 on the surface of the upper electrode, or rare earth elements are incorporated into the piezoelectric layer 204 to improve the electromechanical coupling coefficient, which results in the etching rate of the piezoelectric layer 204 being significantly lower than the etching rate of the dielectric layer 206 on the surface of the electrode. To ensure that the lower electrode lead groove 208 can completely penetrate the piezoelectric layer 204, the etching depth is designed to be relatively large. This means that while the lower electrode lead groove 208 is being formed, the upper electrode 205 at the location of the upper electrode lead groove 207 is already etched through. Consequently, when the lead structure 209 is placed in the upper electrode lead groove 207, only the sidewall of the upper electrode 205 connects to the lead structure 209. This results in a high connection resistance between the upper electrode 205 and the lead structure 209, causing a decrease in the overall performance of the resonator device. However, if the etching of the dielectric layer 206 on the surface of the upper electrode and the etching of the piezoelectric layer 204 on the surface of the lower electrode 203 are completed in two different processes, the manufacturing cost of the resonator will be higher.

[0060] The resonator array of this application has a conductive layer on the top electrode for the purpose of reducing resistance. The lead opening structure can be formed in a single patterning process on the stacked structure, thereby reducing the manufacturing cost of the resonator. On the other hand, even if the etching amount is designed to be large, due to the presence of the conductive layer, the etching is only carried out in the conductive layer and the top electrode will not be etched through. The top electrode lead can make good contact with the conductive layer in the first opening, resulting in a small contact resistance, which can also improve the device performance of the resonator.

[0061] The following description, in conjunction with the accompanying drawings, illustrates the resonator array, filter, electronic device, and resonator fabrication method of embodiments of this application.

[0062] First, the materials of each layer appearing in the resonator group of this application will be described.

[0063] The substrate material can be one of the following: single-crystal silicon, gallium nitride, gallium arsenide, sapphire, quartz, silicon carbide, diamond, etc.

[0064] The material of the bottom electrode (electrode pin) can be molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium, or a composite of the above metals or their alloys.

[0065] Acoustic mirrors can include cavities, Bragg reflectors, or other equivalent forms.

[0066] The piezoelectric layer 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. The piezoelectric layer can also be a polycrystalline piezoelectric material (as opposed to single-crystal, a non-single-crystal material), such as polycrystalline aluminum nitride, zinc oxide, or PZT. The piezoelectric material can also be a rare earth element containing a certain atomic ratio of the above materials. Earth element doped materials 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.

[0067] The top electrode (electrode pin) can be made of the same material as 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.

[0068] The conductive layer can be made of molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium, or a composite or alloy of these metals.

[0069] The material of the dielectric layer on the top electrode surface can be one of AlN, SiN, or SiO2.

[0070] The material of the dielectric layer on the surface of the conductive layer can be one of AlN, SiN, or SiO2.

[0071] The lead wire material can be selected from at least one of molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium, or a composite of the above metals or their alloys.

[0072] It is important to note that in a resonator, the bottom electrode, acoustic mirror, piezoelectric layer, and top electrode are sequentially formed on a substrate using semiconductor processes such as deposition or etching. The bottom and top electrodes connect the two terminals of the resonator to other components in the circuit, respectively; the piezoelectric layer converts electrical energy into sound waves through the piezoelectric effect, which are then reflected by the acoustic mirror to create resonance.

[0073] Figure 3a This is a schematic diagram of the structure of a resonator group provided in an embodiment of this application.

[0074] Reference Figure 3a The resonator group 100 of this application includes at least two resonator units and leads 20 for connecting adjacent resonator units; each resonator unit includes an acoustic mirror 101, a bottom electrode 102, a piezoelectric layer 103, a top electrode 104 and a conductive layer 105 stacked together, wherein the overlapping portions of the acoustic mirror 101, the bottom electrode 102, the piezoelectric layer 103 and the top electrode 104 together form the effective region of the resonator group 100; the conductive layer 105 covers at least a portion of the edge region of the top electrode 104, and the conductive layer 105 and the top electrode 104 are electrically connected;

[0075] At least two resonator units include a first resonator unit 11 and a second resonator unit 12. The first resonator unit 11 has a first opening 111 extending at least to the conductive layer 105, and the second resonator unit 12 has a second opening 121 extending to the bottom electrode 102. The first opening 111 and the second opening 121 are formed in the same patterning process. It is understood that the first opening 111 can extend to the conductive layer 105 and can also extend further to the top electrode 104.

[0076] The lead 20 includes a top electrode lead 21 housed in the first opening 111 and a bottom electrode lead 22 housed in the second opening 121.

[0077] In the above scheme, the first resonator unit 11 has a first opening 111 extending at least to the conductive layer 105, and the second resonator unit 12 has a second opening 121 extending to the bottom electrode 102. Thus, when the top electrode lead 21 in the lead 20 is housed in the first opening 111 and the bottom electrode lead 22 is housed in the second opening 121, the lead 20 can connect the conductive layer 105 of the first resonator unit 11 and the bottom electrode 102 of the second resonator unit 12. Since the conductive layer 105 and the top electrode 104 are electrically connected in the first resonator unit 11, it is equivalent to the lead 20 connecting the top electrode 104 in the first resonator unit 11 and the bottom electrode 102 in the second resonator unit 12.

[0078] Furthermore, the first opening 111 and the second opening 121 are formed in the same patterning process. On the one hand, this saves the etching process and reduces the manufacturing cost of the resonator. On the other hand, even if the etching amount is designed to be large to ensure that the piezoelectric layer 103 in the second resonator unit 12 is completely etched through, the top electrode 104 in the first resonator unit 11 will not be etched through due to the presence of the conductive layer 105. The first opening 111 extends at least into the conductive layer 105, and the top electrode lead 21 can make good contact with the conductive layer 105 in the first opening 111, resulting in a smaller contact resistance and thus improving the device performance of the resonator group 100.

[0079] It should be noted that the resonator group 100 illustrated in this application includes two adjacent resonator units (first resonator unit 11 and second resonator unit 12), and the top electrode 104 of the first resonator unit 11 and the bottom electrode 102 of the second resonator unit 12 are connected by lead wire 20. However, the number of resonator units included in the resonator group 100 of this application is not limited to two, and can be set according to actual needs. When the number of resonator units is other, the connection between adjacent resonator units through lead wire 20 is similar, and will not be described again here.

[0080] In this embodiment, the first resonator unit 11 and the second resonator unit 12 can be formed on a substrate 107. The top electrode 104 of the first resonator unit 11 and the bottom electrode 102 of the second resonator unit 12 are connected by a lead 20. In each resonator unit, the conductive layer 105 covers at least a portion of the edge region of the top electrode 104. This can include the conductive layer 105 covering the entire edge region of the top electrode 104, or the conductive layer 105 covering a portion of the edge region of the top electrode 104, as long as the conductive layer 105 can at least cover a portion of the top electrode 104. However, it is still necessary to maintain an electrical connection between the conductive layer 105 and the top electrode 104, so that when the first opening 111 extends into the conductive layer 105, the portion of the lead 20 located in the first opening 111 can be electrically connected to the top electrode 104 through the conductive layer 105.

[0081] Continue to refer to Figure 3a The first resonator unit 11 has a first opening 111 extending at least to the conductive layer 105, and the second resonator unit 12 has a second opening 121 extending to the bottom electrode 102. The lead 20 includes a top electrode lead 21 accommodated in the first opening 111 and a bottom electrode lead 22 accommodated in the opening of the bottom electrode 102. In this way, the top electrode lead 21 is connected to the conductive layer 105, and the bottom electrode lead 22 is connected to the bottom electrode 102, so that the connection between the top electrode 104 (conductive layer 105) and the bottom electrode 102 can be achieved through the lead 20.

[0082] The first opening 111 and the second opening 121 can be separated from each other, such as Figure 3a and Figure 3b As shown, the first opening 111' and the second opening 121' can also overlap each other in the transverse direction of the resonator group 100, for example, they can partially overlap or completely overlap. In this case, the first opening 111' and the second opening 121' can be connected together to form a single structure.

[0083] When the top electrode lead 21 is housed in the first opening 111, if the first opening 111 extends into the internal region of the conductive layer 105 in the longitudinal direction of the resonator unit, or into the top electrode 104, the top electrode lead 21 simultaneously contacts the side wall and bottom wall of the first opening 111. The area of ​​the conductive metal at the contact part with the conductive layer 105 or the top electrode 104 is large, which can reduce the contact resistance and is beneficial to improving the performance of the resonator group 100 device.

[0084] Optionally, the first opening 111 may extend to the conductive layer 105 or the top electrode 104.

[0085] For example, the first opening 111 can extend from the surface dielectric layer 106 of the conductive layer to the surface of the conductive layer 105. Alternatively, the first opening 111 can extend from the surface dielectric layer 106 of the conductive layer to the longitudinal interior region of the conductive layer 105 within the resonator unit. This facilitates better contact between the top electrode lead 21 and the longitudinal interior of the conductive layer 105.

[0086] Alternatively, the first opening 111 can extend from the surface dielectric layer 106 of the conductive layer to the surface of the top electrode 104. Alternatively, the first opening 111 can extend from the surface dielectric layer 106 of the conductive layer to the internal region of the top electrode 104 in the longitudinal direction of the resonator unit.

[0087] Furthermore, when the conductive layer 105 has a conductive layer surface dielectric layer 106, the first opening 111 can extend from the conductive layer surface dielectric layer 106 to the inner region of the conductive layer 105 or the top electrode 104 in the longitudinal direction of the resonator unit. For example, the resonator assembly 100 also includes a conductive layer surface dielectric layer 106, which is stacked on the side of the conductive layer 105 facing away from the top electrode 104; the first opening 111 penetrates the conductive layer surface dielectric layer 106.

[0088] Optionally, for the second resonator unit 12, the second opening 121 can penetrate the piezoelectric layer 103, thus facilitating the connection between the bottom electrode lead 22 housed in the second opening 121 and the bottom electrode 102. As an optional embodiment, the second opening 121 can extend to the surface of the bottom electrode 102 facing the top electrode 104. As another optional embodiment, the second opening 121 can extend to the internal region of the bottom electrode 102 in the longitudinal direction of the resonator unit, thereby increasing the contact area between the bottom electrode lead 22 and the bottom electrode 102 and reducing contact resistance.

[0089] It should be noted that, since the top electrode 104 is relatively thin, in order to ensure that the first opening 111 will not penetrate the top electrode 104 when the first opening 111 and the second opening 121 are formed in the same patterning process, the thickness of the conductive layer 105 in the first resonator unit 11 in the longitudinal direction can be greater than or equal to the thickness of the piezoelectric layer 103 in that direction. In this way, even if the second opening 121 in the second resonator unit 12 penetrates the piezoelectric layer 103 and is etched into the bottom electrode 102, the etching in the first resonator unit 11 is still only in the conductive layer 105 and does not reach the top electrode 104.

[0090] For example, the thickness of the conductive layer 105 and the piezoelectric layer 103 can be determined according to the etching rate. Specifically, the thickness of the conductive layer 105 can be set such that when the etching of the second opening 121 reaches the inner region of the resonator unit in the longitudinal direction, at least the first opening position will not be etched through the conductive layer 105.

[0091] It should be noted that both the first opening 111 and the second opening 121 should be located outside the effective area, so that the lead 20 is also located outside the effective area.

[0092] Continue to refer to Figure 3a Optionally, the conductive layer 105 may have a suspended portion 110, and there is a suspended gap between the suspended portion and the top electrode 104.

[0093] Figure 3b A schematic diagram of another resonator array structure provided in an embodiment of this application;

[0094] exist Figure 3a Based on the resonator group 100, Figure 3b The resonator group 100' shown has an improved structure for the top electrode. The structure, principle, and function of the other structures, such as the first opening 111 and the second opening 121, have been described in detail above and will not be repeated here.

[0095] Reference Figure 3b In the first resonator unit 11 and the second resonator unit 12, there is a gap 108 between a portion of the piezoelectric layer 103 and the top electrode 104'. The projection of the gap 108 onto the acoustic mirror 101 extends to the outer edge of the acoustic mirror 101, so that a portion of the structure of the top electrode 104' forms a bridge structure.

[0096] Optionally, another portion of the top electrode 104' and the piezoelectric layer 103 may have a gap 109, so that another portion of the top electrode 104' forms a cantilever structure. In this embodiment, the conductive layer 105 may be located above the bridge structure and / or the cantilever structure. Here, the first opening 111 is still located in the first resonator unit 11, and the second opening 121 is still located in the second resonator unit 12; their formation methods, structures, etc., are the same as those in the first resonator unit 12. Figure 3a The resonator group 100 shown is the same, so it will not be described again here.

[0097] As those skilled in the art will understand, the resonator groups according to the present invention can be used to form filters or electronic devices. In addition to the resonator groups 100 and 100' in the above embodiments, the filters may also include other basic elements coupled or disposed thereon. Specifically, the specific structure, function, and main working principle of the resonator groups 100 and 100' in the filters and electronic devices have been described in detail in the foregoing embodiments and will not be repeated here.

[0098] The electronic devices mentioned here include the filters mentioned above. These electronic devices 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 devices, and drones.

[0099] This application also provides a method for manufacturing a resonator, which can be used to manufacture the above-mentioned resonator groups 100 and 100'. The specific structure, function and main working principle of the resonator groups 100 and 100' have been described in detail in the foregoing embodiments, and will not be repeated here.

[0100] Figure 4 This is a schematic flowchart illustrating the resonator fabrication method provided in an embodiment of this application.

[0101] Reference Figure 4 The methods for manufacturing resonators include:

[0102] S10, providing a substrate;

[0103] S20. A stacked structure consisting of an acoustic mirror, a bottom electrode, a piezoelectric layer, a top electrode, and a conductive layer is formed on a substrate, wherein the conductive layer covers a portion of the top electrode.

[0104] S30. A lead opening structure is formed on the stacked structure by a single patterning process. The lead opening structure includes a first opening extending to at least the conductive layer and a second opening extending to the bottom electrode.

[0105] S40, forming a top electrode lead housed in the first opening and a bottom electrode lead housed in the bottom electrode opening.

[0106] In the above scheme, the lead opening structure formed in the stacked structure includes a first opening extending at least to the conductive layer and a second opening extending to the bottom electrode. Since the conductive layer covers a portion of the top electrode, the conductive layer and the top electrode are electrically connected. Thus, when the top electrode lead is housed in the first opening, the conductive layer, i.e., the top electrode, can be led out and used for electrical connection with a predetermined bottom electrode lead; when the bottom electrode lead is housed in the second opening, the bottom electrode can be led out and connected to the predetermined top electrode lead. By connecting the conductive layer of one resonator unit to the bottom electrode of another resonator unit, the top electrode of one resonator unit can be connected to the bottom electrode of another resonator unit.

[0107] Furthermore, this application forms the lead opening structure in a single patterning process on the stacked structure. The first opening and the second opening are formed in the same patterning process. On the one hand, this saves etching processes and reduces the manufacturing cost of the resonator. On the other hand, even if the etching amount is designed to be large in order to completely etch through the piezoelectric layer, the thickness of the conductive layer serves as an etching buffer in the first opening. The patterning operation extends into the conductive layer or partially to the top electrode without etching through the top electrode. The top electrode lead can make good contact with the conductive layer in the first opening, resulting in a lower contact resistance and thus improving the device performance of the resonator.

[0108] Specifically, in step S10, the material constituting the substrate 107 may include one of single-crystal silicon, gallium nitride, gallium arsenide, sapphire, quartz, silicon carbide, and diamond.

[0109] Figure 5 This is a schematic diagram of the resonator structure after step S10, corresponding to the resonator fabrication method provided in the embodiments of this application. Figure 5 As shown, the substrate 107 of the resonator is relatively flat overall, so that other stacked structures can be set on the substrate 107.

[0110] Figure 6 A schematic diagram of the resonator structure after step S20, corresponding to the resonator fabrication method provided in the embodiments of this application.

[0111] Reference Figure 6 In step S20, a stacked structure consisting of an acoustic mirror 101, a bottom electrode 102, a piezoelectric layer 103, a top electrode 104, and a conductive layer 105 is formed on the substrate 107, wherein the conductive layer 105 covers a portion of the top electrode 104. Here, when the number of resonator units to be formed on the substrate 107 is two, the number of stacked structures is two.

[0112] The acoustic mirror 101 can have various different configurations and structures, such as a Bragg reflector or an air cavity.

[0113] The conductive layer 105 can cover a portion of the top electrode 104, thus the conductive layer 105 and the top electrode 104 are electrically connected to each other.

[0114] It should be noted that a resonator group (resonator) may include at least two resonator units, and each resonator unit may include an effective region. The overlapping portion of the acoustic mirror 101, bottom electrode 102, piezoelectric layer 103, and top electrode 104 together forms the effective region of the resonator. Therefore, the stacked structure described in step S20 can be two. Figure 6 In this paper, we take a resonator that includes two adjacent resonator units (first resonator unit 11 and second resonator unit 12) as an example. The top electrode 104 of the first resonator unit 11 and the bottom electrode 102 of the second resonator unit 12 are connected by a lead 20. However, the number of resonator units included in the resonator of this application is not limited to two. It can be set according to actual needs. When the number of resonator units is other, the connection between adjacent resonator units through the lead 20 is similar, and will not be described again here.

[0115] Figure 7 This is a schematic diagram of the resonator structure after step S30, corresponding to the resonator fabrication method provided in the embodiments of this application.

[0116] Reference Figure 7 In step S30, forming a lead opening structure on the stacked structure by one patterning means forming a first opening 111 and a second opening 121 by one patterning.

[0117] Specifically, the first opening 111 and the second opening 121 can be formed by patterning in the same etching process. That is, patterning is performed through an etching process. Generally, in one etching process, the etching rate of each part of the area to be etched is approximately the same. In the process of forming the second opening 121, in order to ensure that the piezoelectric layer 103 can be completely etched through, the etching amount is generally designed according to the thickness of the piezoelectric layer 103. Due to the presence of the conductive layer 105 in the first opening 111, even if the piezoelectric layer 103 is completely penetrated in the second opening 121, the etching in the first opening 111 will only extend into the interior of the conductive layer 105 or partially into the interior of the top electrode 104, and will not penetrate the top electrode 104.

[0118] Optionally, the first opening 111 and the second opening 121 can be patterned in the same etching process, specifically including:

[0119] A second opening 121 is patterned in the edge region of the bottom electrode 102, such that the second opening 121 penetrates the piezoelectric layer 103 and extends to the bottom electrode 102. The edge region of the bottom electrode 102 is the portion of the bottom electrode 102 not covered by the top electrode 104 and is the region planned to connect with the top electrode of the first opening 111. The first opening 111 is patterned on the conductive layer 105. Here, the second opening 121 is formed by etching starting from the piezoelectric layer 103 and can extend from the piezoelectric layer 103 all the way to the bottom electrode 102. As an optional embodiment, the second opening 121 can extend to the surface of the bottom electrode 102 facing the top electrode 104, or as... Figure 7 As shown, the second opening 121 can extend into the inner region of the bottom electrode 102 in the longitudinal direction of the resonator.

[0120] The first opening 111 can extend from the conductive layer 105 all the way to the conductive layer 105 or the top electrode 104 in the longitudinal region of the resonator. Alternatively, if a conductive layer surface dielectric layer 106 is also provided on the top surface of the conductive layer 105, the first opening 111 can extend from the conductive layer surface dielectric layer 106 all the way to the conductive layer 105 or the top electrode 104.

[0121] For example, the first opening 111 can extend from the surface dielectric layer 106 of the conductive layer to the surface of the conductive layer 105. Alternatively, the first opening 111 can extend from the surface dielectric layer 106 of the conductive layer to the longitudinal interior region of the conductive layer 105 within the resonator unit. This facilitates better contact between the top electrode lead 21 and the longitudinal interior of the conductive layer 105.

[0122] Alternatively, the first opening 111 can extend from the surface dielectric layer 106 of the conductive layer to the surface of the top electrode 104. Alternatively, the first opening 111 can extend from the surface dielectric layer 106 of the conductive layer to the internal region of the top electrode 104 in the longitudinal direction of the resonator unit.

[0123] Figure 8 A schematic diagram of the resonator structure after step S40, corresponding to the resonator fabrication method provided in the embodiments of this application.

[0124] Reference Figure 8 In step S40, a top electrode lead 21 accommodated within the first opening 111 and a bottom electrode lead 22 accommodated within the second opening 121 can be formed. It is understood that... Figure 8In this design, a top electrode lead 21 is formed in the first opening 111 of the first resonator unit 11, and a bottom electrode lead 22 is formed in the second opening 121 of the second resonator unit 12. Here, simply connecting the top electrode lead 21 and the bottom electrode lead 22 achieves the connection between the top electrode 104 of the first resonator unit 11 and the bottom electrode 102 of the second resonator unit 12. Specifically, the top electrode lead 21 and the bottom electrode lead 22, as well as the connection between them, can be formed simultaneously through a single patterning step.

[0125] For example, a lead layer is provided on the lead opening structure, and the lead layer is graphically represented, specifically including:

[0126] A lead layer is disposed on the laminated structure, for example, a lead layer is deposited on the laminated structure.

[0127] The lead layer is patterned to form leads 20 at positions corresponding to the lead opening structure. The portion of the lead 20 housed in the first opening 111 forms the top electrode lead 21, and the portion of the lead 20 housed in the second opening 121 forms the bottom electrode lead 22.

[0128] It should be noted that when the number of resonator elements included in the resonator is otherwise specified, the connection between any two adjacent resonator elements can be referenced. Figure 8 The first resonator unit 11 and the second resonator unit 12 are in the circuit. Alternatively, the top electrode leads 21 of two adjacent resonator units can be connected. The specific connection method can be set according to the actual circuit requirements, which will not be elaborated here.

[0129] Based on the above solution, the embodiments of this application further improve the relative positions of the first opening and the second opening. For example, the structural parts of the first opening and the second opening can overlap. It is understood that the other structural parts are the same as those in the aforementioned embodiments, and will not be described again here.

[0130] Figure 9 This is a schematic diagram of another structure of the resonator after step S40, corresponding to the resonator fabrication method provided in the embodiments of this application.

[0131] Reference Figure 9 As another possible implementation, a lead opening structure is formed in a patterned manner on the stacked structure, specifically including:

[0132] The first opening 111' and the second opening 121' are patterned and interconnected in the same etching process.

[0133] exist Figure 7 and Figure 8In the illustrated scheme, the first opening 111 and the second opening 121 are spaced apart in the transverse direction of the resonator group 100. Figure 9 In the illustrated scheme, the first opening 111' and the second opening 121' overlap each other in the transverse direction of the resonator group and can be connected as a whole. The lead 20' is located in the first opening 111' and the second opening 121' for electrical connection.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] 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.

[0138] 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.

[0139] 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.

[0140] 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 therein. Such 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 method for manufacturing a resonator, characterized in that, include: Provide substrate; A stacked structure consisting of an acoustic mirror, a bottom electrode, a piezoelectric layer, a top electrode, and a conductive layer is formed on the substrate, wherein the conductive layer covers a portion of the top electrode. A lead opening structure is formed on the stacked structure through a single patterning process. The lead opening structure includes a first opening extending to the conductive layer and a second opening extending to the bottom electrode. Specifically, forming the lead opening structure on the stacked structure through a single patterning process includes patterning the first opening and the second opening, which are interconnected, through the same etching process. A top electrode lead is formed that is housed in the first opening and a bottom electrode lead is housed in the bottom electrode opening.

2. The resonator fabrication method according to claim 1, characterized in that, The process of patterning the first opening and the second opening separately through the same etching process specifically includes: The second opening is patterned in the edge region of the bottom electrode so that the second opening penetrates the piezoelectric layer and extends to the bottom electrode, wherein the edge region of the bottom electrode is the part of the bottom electrode not covered by the top electrode; The first opening is patterned on the conductive layer.

3. The resonator fabrication method according to claim 2, characterized in that, The second opening extends to the side surface of the bottom electrode facing the top electrode; or The second opening extends into the inner region of the bottom electrode in the longitudinal direction of the resonator.

4. The resonator fabrication method according to claim 2, characterized in that, The first opening extends to the conductive layer or the top electrode.

5. The resonator fabrication method according to claim 4, characterized in that, The first opening extends to the surface of the conductive layer; or The first opening extends into the conductive layer within the longitudinal region of the resonator; or The first opening extends to the surface of the top electrode; or The first opening extends into the inner region of the top electrode in the longitudinal direction of the resonator.

6. The resonator fabrication method according to claim 2, characterized in that, A lead layer is disposed on the lead opening structure, and the lead layer is patterned, specifically including: A lead layer is provided on the laminated structure; The lead layer is patterned to form leads at positions corresponding to the lead opening structure. The portion of the lead housed in the first opening forms the top electrode lead, and the portion of the lead housed in the second opening forms the bottom electrode lead.

7. A resonator array, characterized in that, The device includes at least two resonator units and leads for connecting adjacent resonator units; each resonator unit includes a stacked acoustic mirror, a bottom electrode, a piezoelectric layer, a top electrode, and a conductive layer, the overlapping portion of the acoustic mirror, the bottom electrode, the piezoelectric layer, and the top electrode together forming the effective area of ​​the resonator unit; the conductive layer covers at least a portion of the edge region of the top electrode, and the conductive layer and the top electrode are electrically connected; At least two of the resonator units include a first resonator unit and a second resonator unit, the first resonator unit having a first opening extending at least to the conductive layer, and the second resonator unit having a second opening extending to the bottom electrode, the first opening and the second opening being formed in the same patterning process; The leads include a top electrode lead housed in the first opening and a bottom electrode lead housed in the second opening; the first opening and the second opening are patterned and interconnected through the same etching process.

8. The resonator array according to claim 7, characterized in that, The first opening extends to the conductive layer or the top electrode.

9. The resonator array according to claim 8, characterized in that, The first opening extends to the surface of the conductive layer; or The first opening extends into the conductive layer within the longitudinal region of the resonator; or The first opening extends to the surface of the top electrode; or The first opening extends into the inner region of the top electrode in the longitudinal direction of the resonator.

10. The resonator array according to claim 7, characterized in that, The second opening penetrates the piezoelectric layer.

11. The resonator array according to claim 10, characterized in that, The second opening extends to the side surface of the bottom electrode facing the top electrode.

12. The resonator array according to claim 10, characterized in that, The second opening extends into the inner region of the bottom electrode in the longitudinal direction of the resonator unit.

13. The resonator array according to any one of claims 7-12, characterized in that, The thickness of the conductive layer in the longitudinal direction of the resonator unit is greater than or equal to the thickness of the piezoelectric layer in the longitudinal direction of the resonator unit.

14. The resonator array according to any one of claims 7-12, characterized in that, Both the first opening and the second opening are located outside the effective area.

15. The resonator assembly according to any one of claims 7-12, characterized in that, The conductive layer has a suspended portion, and there is a suspended gap between the suspended portion and the top electrode.

16. The resonator array according to any one of claims 7-12, characterized in that, It also includes a conductive layer surface dielectric layer, which is stacked on the side of the conductive layer opposite to the top electrode; the first opening penetrates the conductive layer surface dielectric layer.

17. The resonator array according to any one of claims 7-12, characterized in that, The first opening and the second opening have overlapping portions in the transverse direction of the resonator unit.

18. The resonator assembly according to any one of claims 7-12, characterized in that, The lead wire is made of at least one of molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, and chromium.

19. A filter, characterized in that, Includes the resonator array as described in any one of claims 7-18.

20. An electronic device, characterized in that, Includes the filter as described in claim 19.

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