Resonator and acoustic wave device

Abstract

The utility model provides a resonator and an acoustic wave device. The resonator includes: a substrate; the reflection structure, the first electrode layer, the piezoelectric layer and the second electrode layer are sequentially arranged on the substrate in a stacked mode, and the overlapped area of the reflection structure, the first electrode layer, the piezoelectric layer and the second electrode layer in the direction perpendicular to the substrate is a resonance area; the first functional layer is arranged between the piezoelectric layer and the second electrode layer, and at least part of the first functional layer is arranged in a non-resonance area; the second functional layer is arranged on the surface, which is not covered by the second electrode layer, of the piezoelectric layer; wherein the size of at least part of the first functional layer and / or at least part of the second functional layer in the direction perpendicular to the substrate is reduced in the direction away from the resonance area; and the frequency repairing layer is arranged on the surfaces, far away from the substrate, of the second electrode layer and the second functional layer.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of semiconductor, including but not limited to a resonator and acoustic wave device. BACKGROUND

[0002] Bulk acoustic wave resonator (Bulk Acoustic Wave, BAW) as piezoelectric device important member, because it has size small, resonant frequency high and quality factor (Quality Factor, Q value) etc. Many advantages, is playing an important role in the field of communication technology. However, in the process of resonance, part of the transverse wave or clutter will interfere with the normal resonant acoustic wave, thereby causing energy loss, and then reducing the Q value of bulk acoustic wave resonator.

[0003] Therefore, it is urgent to improve the resonator to improve its performance. UTILITY MODEL CONTENT

[0004] Therefore, the utility model provides a resonator and acoustic wave device.

[0005] First, the utility model provides a resonator, the resonator includes: substrate, reflection structure, first electrode layer, piezoelectric layer and second electrode layer are sequentially stacked on the substrate, the reflection structure, the first electrode layer, the piezoelectric layer and the second electrode layer along the direction of the substrate direction on the overlapping region is resonant region, first functional layer is arranged between the piezoelectric layer and the second electrode layer, at least part of the first functional layer is arranged in non-resonant region, second functional layer is arranged on the surface of the piezoelectric layer not covered by the second electrode layer, wherein, at least part of the first functional layer and / or at least part of the second functional layer along the direction of the substrate direction on the size decreases along the direction away from the resonant region, the frequency correction layer is arranged on the surface of the second electrode layer and the second functional layer away from the substrate.

[0006] In some embodiments, at least part of the surface of the first functional layer away from the substrate has a first rough surface, and / or at least part of the surface of the second functional layer away from the substrate has a second rough surface.

[0007] In some embodiments, the first recessed structure in the first rough surface of the first functional layer and the first protruded structure in the surface of the substrate proximate to the second electrode layer correspondingly contact; wherein the ratio between the dimension of the first protruded structure along the direction perpendicular to the substrate and the dimension of the first functional layer along the direction perpendicular to the substrate ranges from 0.005 to 0.995; and / or, the second recessed structure in the second rough surface of the second functional layer and the second protruded structure in the surface of the substrate proximate to the frequency-modifying layer correspondingly contact; wherein the ratio between the dimension of the second protruded structure along the direction perpendicular to the substrate and the dimension of the second functional layer along the direction perpendicular to the substrate ranges from 0.005 to 0.995.

[0008] In some embodiments, the first functional layer has a third rough surface proximate to at least part of the surface of the substrate; and / or, the second functional layer has a fourth rough surface proximate to at least part of the surface of the substrate.

[0009] In some embodiments, the third recessed structure in the third rough surface of the first functional layer and the third protruded structure in the surface of the substrate distal to the piezoelectric layer correspondingly contact; wherein the ratio between the dimension of the third protruded structure along the direction perpendicular to the substrate and the dimension of the first functional layer along the direction perpendicular to the substrate ranges from 0.005 to 0.995; and / or, the fourth recessed structure in the fourth rough surface of the second functional layer and the fourth protruded structure in the surface of the substrate distal to the piezoelectric layer correspondingly contact; wherein the ratio between the dimension of the fourth protruded structure along the direction perpendicular to the substrate and the dimension of the second functional layer along the direction perpendicular to the substrate ranges from 0.005 to 0.995.

[0010] In some embodiments, the angle between the surface of the first functional layer at the portion farthest from the resonant region and the substrate ranges from 3 degrees to 60 degrees when the dimension of at least part of the first functional layer along the direction perpendicular to the substrate decreases along the direction distal to the resonant region; and / or, the angle between the surface of the second functional layer at the portion farthest from the resonant region and the substrate ranges from 3 degrees to 60 degrees when the dimension of at least part of the second functional layer along the direction perpendicular to the substrate decreases along the direction distal to the resonant region.

[0011] In some embodiments, the angle between the surface of the first functional layer at the portion farthest from the resonant region and the substrate ranges from 20 degrees to 45 degrees when the dimension of at least part of the first functional layer along the direction perpendicular to the substrate decreases along the direction distal to the resonant region; and / or, the angle between the surface of the second functional layer at the portion farthest from the resonant region and the substrate ranges from 20 degrees to 45 degrees when the dimension of at least part of the second functional layer along the direction perpendicular to the substrate decreases along the direction distal to the resonant region.

[0012] In some embodiments, a ratio between a minimum dimension and a maximum dimension of the first functional layer along a direction perpendicular to the substrate direction when the dimension of at least part of the first functional layer along the direction perpendicular to the substrate direction decreases in a direction away from the resonant region ranges from 0.005 to 0.995; a ratio between a minimum dimension and a maximum dimension of the second functional layer along a direction perpendicular to the substrate direction when the dimension of at least part of the second functional layer along the direction perpendicular to the substrate direction decreases in a direction away from the resonant region ranges from 0.005 to 0.995.

[0013] In some embodiments, a ratio between a minimum dimension and a maximum dimension of the first functional layer along a direction perpendicular to the substrate direction when the dimension of at least part of the first functional layer along the direction perpendicular to the substrate direction decreases in a direction away from the resonant region ranges from 0.75 to 0.95; a ratio between a minimum dimension and a maximum dimension of the second functional layer along a direction perpendicular to the substrate direction when the dimension of at least part of the second functional layer along the direction perpendicular to the substrate direction decreases in a direction away from the resonant region ranges from 0.75 to 0.95.

[0014] In some embodiments, the substrate comprises a first portion in contact with the reflective structure and a second portion not in contact with the reflective structure, a thickness of the first portion of the substrate is greater than a thickness of the second portion of the substrate.

[0015] In some embodiments, a ratio between a difference between the thickness of the first portion of the substrate and the thickness of the second portion of the substrate and a dimension of the reflective structure along a direction perpendicular to the substrate direction ranges from 0.01 to 0.2.

[0016] In some embodiments, a ratio between a difference between the thickness of the first portion of the substrate and the thickness of the second portion of the substrate and a dimension of the reflective structure along a direction perpendicular to the substrate direction ranges from 0.07 to 0.1.

[0017] In some embodiments, the resonator further comprises a heat conducting structure disposed in the second portion of the substrate, the heat conducting structure being in contact with the first electrode layer.

[0018] In some embodiments, an acoustic impedance of the first functional layer material is less than or equal to an acoustic impedance of air, an acoustic impedance of the second functional layer material is less than or equal to an acoustic impedance of air.

[0019] In a second aspect, the utility model provides a kind of acoustic wave device, the acoustic wave device includes: at least one resonator in the above technical solution.

[0020] The utility model provides a resonator and acoustic wave device. In the utility model embodiment, the size of at least part of the first functional layer and / or at least part of the second functional layer in the direction perpendicular to the substrate decreases in the direction away from the resonance region, which can reduce the interference of the transverse wave or the miscellaneous wave on the normal resonance acoustic wave, thereby reducing the energy loss of the normal resonance acoustic wave of the resonator, and improving the Q value of the resonator. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 A cross-sectional view of the resonator provided by the first embodiment of the utility model;

[0022] Figure 2 A cross-sectional view of the resonator provided by the second embodiment of the utility model;

[0023] Figure 3 A cross-sectional view of the resonator provided by the third embodiment of the utility model;

[0024] Figure 4 A cross-sectional view of the resonator provided by the fourth embodiment of the utility model;

[0025] Figure 5 A block diagram of the acoustic wave device provided by the utility model. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the embodiments of the utility model and the drawings. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the utility model.

[0027] In the following description, a large number of specific details are given to provide a more thorough understanding of the utility model. However, it is obvious for those skilled in the art that the utility model can be implemented without one or more of these details. In other examples, in order to avoid confusion with the utility model, some technical features known in the art are not described; that is, not all features of the actual embodiments are described here, and the known functions and structures are not described in detail.

[0028] In the drawings, the size of the layer, region, element and its relative size can be exaggerated for clarity. The same reference signs represent the same elements throughout.

[0029] It will be understood that when an element or layer is referred to as being "on", "adjacent", "connected" or "coupled" to another element or layer, it can be directly on, adjacent, connected or coupled to the other element or layer or intervening elements or layers can be present. In contrast, when an element is referred to as being "directly on", "directly adjacent", "directly connected" or "directly coupled" to another element or layer, there are no intervening elements or layers present. It will be understood that, although the terms first, second, third, etc. can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present application. Similarly, a second element, component, region, layer or section discussed below could be termed a first element, component, region, layer or section without departing from the teachings of the present application.

[0030] Spatially relative terms, such as "beneath", "below", "lower", "under", "above", "upper" and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" or "over" the other elements or features. Thus, the exemplary term "below" can encompass both an orientation of above and below. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0031] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising", when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0032] In order to thoroughly understand the present application, detailed steps and detailed structures will be proposed in the following description, so as to explain the technical scheme of the present application. The preferred embodiments of the present application are described in detail as follows, however, in addition to these detailed descriptions, the present application can also have other implementation manners.

[0033] Before introducing the embodiments of the present disclosure, each direction possibly involved in the embodiments of the present disclosure is defined. The X direction is defined in the plane where the substrate is located, and the direction perpendicular to the substrate is defined as the Z direction, and the X direction and the Z direction are perpendicular to each other.

[0034] Reference Figure 1 , Figure 1 A cross-sectional view of the resonator provided by the first embodiment of the present application. As shown in Figure 1 The present application provides a resonator, which comprises: a substrate 102; a reflection structure 104, a first electrode layer 106, a piezoelectric layer 112 and a second electrode layer 114 which are sequentially stacked on the substrate 102, and the overlapping area of the reflection structure 104, the first electrode layer 106, the piezoelectric layer 112 and the second electrode layer 114 in the Z direction is a resonance area 108; a first functional layer 116 provided between the piezoelectric layer 112 and the second electrode layer 114, at least part of the first functional layer 116 is provided in a non-resonance area 110; a second functional layer 118 provided on the surface of the piezoelectric layer 112 which is not covered by the second electrode layer 114; wherein the size of at least part of the first functional layer 116 and / or at least part of the second functional layer 118 in the Z direction decreases in the direction away from the resonance area 108; a frequency correction layer 120 provided on the surface of the second electrode layer 114 and the second functional layer 118 away from the substrate 102.

[0035] In some embodiments, the material of the substrate 102 can include elemental semiconductor materials such as silicon (Si) or germanium (Ge) and the like, III-V compound semiconductor materials, II-VI compound semiconductor materials and organic semiconductor materials or other semiconductor materials known in the art.

[0036] Here, the reflection structure 104 can be used to reflect the acoustic wave signal. When the acoustic wave signal generated by the piezoelectric layer 112 propagates to the reflection structure 104, the acoustic wave signal can be totally reflected at the interface where the first electrode layer 106 and the reflection structure 104 contact, so that the acoustic wave signal is reflected back into the piezoelectric layer 112. In this way, the energy of the acoustic wave signal generated by the piezoelectric layer 112 can be confined in the piezoelectric layer 112, reducing the energy loss of the acoustic wave signal and improving the quality of the acoustic wave signal transmitted by the resonator.

[0037] In some embodiments, the reflection structure 104 can include an air cavity.

[0038] In some embodiments, the reflective structure 104 can include a Bragg reflective structure, where the Bragg reflective structure includes two medium materials with different acoustic impedances arranged in a stack.

[0039] Here, the first electrode layer 106 can also be referred to as a lower electrode layer, and the second electrode layer 114 can also be referred to as an upper electrode layer through which an electrical signal can be applied to the resonator 100. In some embodiments, the materials of the first electrode layer 106 and the second electrode layer 114 can be the same and include a conductive material composed of a conductive metal or an alloy of a conductive metal, such as aluminum (Al), molybdenum (Mo), or platinum (Pt), etc.

[0040] Here, the piezoelectric layer 112 can be used to generate vibrations according to the inverse piezoelectric effect, to convert an electrical signal applied to the first electrode layer 106 and the second electrode layer 114 into an acoustic signal, to achieve conversion of electrical energy into mechanical energy. In some embodiments, the material of the piezoelectric layer 112 can include a material having piezoelectric properties. For example, aluminum nitride, zinc oxide, lithium tantalate, lead zirconate titanate, or barium titanate, etc.

[0041] Here, the resonator 100 includes a resonant region 108 and a non-resonant region 110. The overlapping region of the reflective structure 104, the first electrode layer 106, the piezoelectric layer 112, and the second electrode layer 114 in the Z direction is determined as the resonant region 108, and the other region is determined as the non-resonant region 110.

[0042] Here, the direction away from the resonant region 108 is different depending on the position of the structure. For the first functional layer 116, the direction away from the resonant region 108 is the negative direction of the X direction; for the second functional layer 118, the direction away from the resonant region 108 is the positive direction of the X direction.

[0043] In some embodiments, the shape of the resonant region 108 in the orthographic projection on the substrate 102 can include a polygon, a circle, or a closed figure composed of two straight line segments and an arc segment. Exemplarily, the shape of the resonant region 108 in the orthographic projection on the substrate 102 can be a closed figure composed of two straight line segments and an arc segment, and the lengths of the two straight line segments can be the same.

[0044] Here, the second functional layer 118 is arranged between the piezoelectric layer 112 and the frequency correction layer 120, and at least part of the second functional layer 118, or even the entire second functional layer 118, can be arranged in the non-resonant region 110. In some embodiments, the material of the second functional layer 118 can include a low acoustic impedance material, i.e., the acoustic impedance of the material of the second functional layer 118 is less than or equal to the acoustic impedance of air. In some embodiments, the material of the second functional layer 118 can include air or silicon dioxide, etc.

[0045] In some embodiments, at least a portion of the second functional layer 118 decreases in size along the Z-direction away from the resonant region 108. Here, the size of the second functional layer 118 along the Z-direction can be referred to as the thickness of the second functional layer 118. The thickness of a portion of the second functional layer 118 decreases in size along the direction away from the resonant region 108, while the thickness of other portions of the second functional layer 118 remains unchanged; or, the thickness of all the second functional layers 118 decreases in size along the direction away from the resonant region 108.

[0046] Will Figure 1 The second functional layer 118, indicated by the dashed box, is magnified. The second functional layer 118 includes a first portion 118a and a second portion 118b. The surfaces of the first portion 118a near and away from the substrate 102 both form an angle with the plane containing the substrate 102. The surface of the second portion 118b near the substrate 102 is parallel to the plane containing the substrate 102, and the surface of the second portion 118b away from the substrate 102 also forms an angle with the plane containing the substrate 102. In some embodiments, the thickness of both the first portion 118a and the second portion 118b decreases along the direction away from the resonant region 108. In other embodiments, the thickness of the first portion 118a remains constant, while the thickness of the second portion 118b decreases along the direction away from the resonant region 108. Of course, this disclosure does not specifically limit the ratio between the portion where the thickness of the second functional layer 118 remains unchanged and the portion where the thickness of the second functional layer 118 decreases in the direction away from the resonant region 108. The division of the first portion 118a and the second portion 118b described above is only for illustrative purposes and does not constitute a limitation on the scope of protection of this disclosure.

[0047] This disclosure does not impose any particular limitation on the thickness variation law of at least a portion of the second functional layer 118 decreasing in the direction away from the resonant region 108. For example, the thickness of the second functional layer 118 may gradually decrease in the direction away from the resonant region 108; or, for example, the thickness of the second functional layer 118 may decrease in a gradient in the direction away from the resonant region 108.

[0048] Here, the first functional layer 116 is disposed between the piezoelectric layer 112 and the second electrode layer 114, and at least part, or even all, of the first functional layer 116 may be disposed in the non-resonant region 110. In some embodiments, the material of the first functional layer 116 may include a low acoustic impedance material, that is, the acoustic impedance of the material of the first functional layer 116 is less than or equal to the acoustic impedance of air. In some embodiments, the material of the first functional layer 116 may include air or silicon dioxide, etc.

[0049] In some embodiments, the thickness of at least part of the first functional layer 116 decreases in a direction away from the resonance region 108. Here, the thickness of part of the first functional layer 116 decreases in a direction away from the resonance region 108, and the thickness of other part of the first functional layer 116 remains unchanged; or the thickness of the entire first functional layer 116 decreases in a direction away from the resonance region 108. The thickness variation of the first functional layer 116 can refer to the description of the second functional layer 118, which will not be repeated here.

[0050] In some embodiments, the resonator 100 can include the first functional layer 116 and the second functional layer 118, the thickness of the first functional layer 116 decreases in a direction away from the resonance region 108, and the thickness of the second functional layer 118 remains unchanged; the thickness of the first functional layer 116 remains unchanged, and the thickness of the second functional layer 118 decreases in a direction away from the resonance region 108.

[0051] In some embodiments, the resonator 100 can include the first functional layer 116 and the second functional layer 118, the thickness of the first functional layer 116 decreases in a direction away from the resonance region 108, and the thickness of the second functional layer 118 decreases in a direction away from the resonance region 108.

[0052] In the embodiments of the utility model, the thickness of at least part of the first functional layer and / or at least part of the second functional layer decreases in a direction away from the resonance region, that is, the thickness space occupied by at least part of the first functional layer and / or at least part of the second functional layer decreases in a direction away from the resonance region, which can reduce the interference of transverse waves or miscellaneous waves on normal resonance acoustic waves, thereby reducing the energy loss of normal resonance acoustic waves of the resonator, and further improving the Q value of the resonator.

[0053] Here, the frequency correction layer 120 can not only serve as a protective layer to reduce oxidation caused by exposure of the second electrode layer 114 to the external environment and maintain the stability of the resonator, but also can adjust the resonance frequency of the resonator 100 by controlling the size of the frequency correction layer 120 in the Z direction. In some embodiments, the material of the frequency correction layer 120 can include silicon dioxide or aluminum nitride, etc.

[0054] In some embodiments, the materials of the piezoelectric layer 112 and the frequency correction layer 120 can be the same.

[0055] In some embodiments, when the thickness of at least part of the first functional layer 116 decreases in the direction away from the resonant region 108, the included angle between the surface of the part of the first functional layer 116 farthest from the resonant region 108 and the substrate 102 ranges from 3 degrees to 60 degrees; optionally, the included angle ranges from 20 degrees to 45 degrees. Figure 1 In some embodiments, when the thickness of at least part of the second functional layer 118 decreases in the direction away from the resonant region 108, the included angle between the surface of the part of the second functional layer 118 farthest from the resonant region 108 (as shown by the dashed circle in the middle) and the substrate 102 ranges from 3 degrees to 60 degrees; optionally, the included angle ranges from 20 degrees to 45 degrees.

[0056] Here, the limitation of the included angle between the surface of the part of the first functional layer 116 (or the second functional layer 118) farthest from the resonant region 108 and the substrate 102 within the above-mentioned included angle range can further reduce the energy loss of the normal resonant acoustic wave of the resonator, thereby improving the Q value of the resonator.

[0057] In some embodiments, when the thickness of at least part of the first functional layer 116 decreases in the direction away from the resonant region 108, the ratio between the minimum dimension (i.e., the minimum thickness) and the maximum dimension (i.e., the maximum thickness) of the first functional layer 116 in the Z direction ranges from 0.005 to 0.995; optionally, the ratio ranges from 0.75 to 0.95. In some embodiments, when the thickness of at least part of the second functional layer 118 decreases in the direction away from the resonant region 108, the ratio between the minimum dimension (i.e., the minimum thickness) and the maximum dimension (i.e., the maximum thickness) of the second functional layer 118 in the Z direction ranges from 0.005 to 0.995; optionally, the ratio ranges from 0.75 to 0.95.

[0058] Here, the thickness of the first functional layer 116 decreases in the direction away from the resonant region 108, and thus the minimum thickness position of the first functional layer 116 is the first functional layer 116 at the position farthest from the resonant region 108. Similarly, the minimum thickness position of the second functional layer 118 is the second functional layer 118 at the position farthest from the resonant region 108.

[0059] Here, the disclosure does not have special limitations on the thickness variation of the first functional layer 116, and thus the maximum thickness position of the first functional layer 116 can be the first functional layer 116 at the position closest to the resonant region 108 or the first functional layer 116 at other positions. Similarly, the maximum thickness position of the second functional layer 118 can be the second functional layer 118 at the position closest to the resonant region 108 or the second functional layer 118 at other positions.

[0060] Here, limiting the ratio between the minimum and maximum thickness of the first functional layer 116 (or the second functional layer 118) to within the aforementioned limited thickness ratio range can further reduce the energy loss of the normal resonant sound wave of the resonator, thereby improving the Q value of the resonator.

[0061] refer to Figure 2 , Figure 2 This is a cross-sectional view of the resonator provided in the second embodiment of this utility model. Figure 2 As shown, this utility model provides a resonator 200, which includes: a substrate 202; a reflective structure 204, a first electrode layer 206, a piezoelectric layer 212, and a second electrode layer 214 sequentially stacked on the substrate 202. The overlapping area of ​​the reflective structure 204, the first electrode layer 206, the piezoelectric layer 212, and the second electrode layer 214 along the Z direction is the resonant region 208, and the other areas are non-resonant regions 210.

[0062] In some embodiments, at least a portion of the surface of the first functional layer 216 away from the substrate 202 has a first rough surface 222. A first recessed structure 224 in the first rough surface 222 of the first functional layer 216 and a first protrusion 226 in the surface of the second electrode layer 214 near the substrate 202 are in corresponding contact; wherein the ratio between the dimensions of the first protrusion 226 and the first functional layer 216 along the Z direction ranges from 0.005 to 0.995. Optionally, the ratio between the dimensions of the first protrusion 226 and the first functional layer 216 along the Z direction ranges from 0.15 to 0.35.

[0063] Here, the first functional layer 216 has two surfaces arranged opposite each other along the Z direction. The surface of the first functional layer 216 near the substrate 202 is in contact with the piezoelectric layer 212, and the surface of the first functional layer 216 away from the substrate 202 is in contact with the second electrode layer 214. Figure 2 The diagram illustrates a first rough surface 222 on the surface of the first functional layer 216 away from the substrate 202. Since this surface is in contact with the second electrode layer 214, the first recessed structure 224 in the first rough surface 222 and the first protruding structure 226 on the surface of the second electrode layer 214 near the substrate 202 form complementary shapes. In other words, the recessed portion in the first rough surface 222 corresponds to the protruding portion in the second electrode layer 214.

[0064] Exemplarily, forming the first rough surface 222 can include the following steps: the uneven topography can be formed on the part of the surface of the first functional layer 216 away from the substrate 202 by a surface treatment process. The uneven topography can also be formed on the entire surface of the first functional layer 216 away from the substrate 202 by a surface treatment process. The present disclosure does not have special limitations on the specific position of the first rough surface 222 in the surface of the first functional layer 216 away from the substrate 202. In the present embodiment, the uneven first rough surface 222 obtained by the surface treatment process is composed of repeated grooves and protrusions.

[0065] In some embodiments, after the first rough surface 222 is formed on at least part of the surface of the first functional layer 216 away from the substrate 202; the subsequent deposition of the second electrode layer 214 will also replicate this uneven topography in the corresponding position, and the second electrode layer 214 will form an uneven topography in the corresponding position on the surface close to the substrate 202 and the surface away from the substrate 202; the subsequent deposition of the frequency correction layer 220 will also replicate this uneven topography in the corresponding position, and the frequency correction layer 220 will form an uneven topography in the corresponding position on the surface close to the substrate 202 and the surface away from the substrate 202. Figure 2 In some embodiments, the frequency correction layer 220 is omitted to show the uneven topography formed in the corresponding position on the surface close to the substrate 202 and the surface away from the substrate 202, which does not constitute a limitation on the protection scope of the present disclosure.

[0066] In some embodiments, at least part of the surface of the second functional layer 218 away from the substrate 202 has a second rough surface 228. The second recess structure 230 in the second rough surface 228 of the second functional layer 218 and the second protrusion structure 232 in the surface of the frequency correction layer 220 close to the substrate 202 correspondingly contact; wherein the ratio between the size of the second protrusion structure 232 and the size of the second functional layer 218 in the Z direction is in the range of 0.005 to 0.995. Optionally, the ratio between the size of the second protrusion structure 232 and the size of the second functional layer 218 in the Z direction is in the range of 0.15 to 0.35.

[0067] Here, the second functional layer 218 has two surfaces arranged in opposite directions along the Z direction, the surface of the second functional layer 218 close to the substrate 202 contacts the piezoelectric layer 212, and the surface of the second functional layer 218 away from the substrate 202 contacts the frequency correction layer 220. The second functional layer 218 is arranged between the piezoelectric layer 212 and the frequency correction layer 220. Figure 2The second functional layer 218 shown in the second dashed box is enlarged. The part of the surface of the second functional layer 218 away from the substrate 202 is a second rough surface 228. Since the surface is in contact with the tuning layer 220, the second recessed structure 230 in the second rough surface 228 and the second protruding structure 232 in the surface of the tuning layer 220 close to the substrate 202 form complementary shapes. In other words, the recessed part in the second rough surface 228 corresponds to the protruding part in the tuning layer 220.

[0068] Exemplarily, forming the second rough surface 228 can include the following steps. The uneven topography can be formed on the part of the surface of the second functional layer 218 away from the substrate 202 by a surface treatment process. The uneven topography can also be formed on the whole surface of the second functional layer 218 away from the substrate 202 by the surface treatment process. The present disclosure does not have special limitations on the specific position of the second rough surface 228 in the surface of the second functional layer 218 away from the substrate 202. In the embodiment, the uneven second rough surface 228 obtained by the surface treatment process is composed of repeated grooves and protrusions.

[0069] In some embodiments, after the second rough surface 228 is formed on at least part of the surface of the second functional layer 218 away from the substrate 202; the subsequent deposition of the tuning layer 220 also replicates the uneven topography in the corresponding position, and the surface of the tuning layer 220 close to the substrate 202 and the surface of the tuning layer 220 away from the substrate 202 both form uneven topography in the corresponding position.

[0070] In the embodiments of the present disclosure, the first rough surface and the second rough surface as the rough reflection surface can scatter the transverse wave or the clutter wave, thereby effectively consuming the energy of the transverse wave or the clutter wave, avoiding the transverse wave or the clutter wave from returning to the resonance region, reducing the interference of the transverse wave or the clutter wave on the normal resonance acoustic wave, thereby reducing the energy loss of the normal resonance acoustic wave of the resonator, and further improving the Q value of the resonator.

[0071] Here, limiting the ratio range between the first protruding structure 226 and the thickness of the first functional layer 216 within the above-mentioned limited thickness ratio range, and limiting the ratio range between the second protruding structure 232 and the thickness of the second functional layer 218 within the above-mentioned limited thickness ratio range, can further reduce the energy loss of the normal resonance acoustic wave of the resonator, thereby improving the Q value of the resonator.

[0072] Reference Figure 3 , Figure 3 The sectional view of the resonator provided by the third embodiment of the present application is shown in FIG. 6. As shown in FIG. 6, the resonator comprises a substrate 202, a first functional layer 216, a second functional layer 218, and a tuning layer 220. The first functional layer 216 is formed on the surface of the substrate 202. The second functional layer 218 is formed on the surface of the first functional layer 216. The tuning layer 220 is formed on the surface of the second functional layer 218. Figure 3As shown, the utility model provides a kind of resonator, the resonator 300 includes: substrate 302;Reflective structure 304, first electrode layer 306, piezoelectric layer 312 and second electrode layer 314 are sequentially stacked on substrate 302, and the overlapping area of reflective structure 304, first electrode layer 306, piezoelectric layer 312 and second electrode layer 314 along Z direction is resonant region 308, and other regions are non-resonant region 310.

[0073] In some embodiments, the third rough surface 334 of the first functional layer 316 is close to at least part of the surface of the substrate. The third recessed structure 336 in the third rough surface 334 of the first functional layer 316 and the third protruding structure 338 in the surface of the piezoelectric layer 312 away from the substrate 302 correspondingly contact; wherein the ratio between the size of the third protruding structure 338 along the Z direction and the size of the first functional layer 316 along the Z direction ranges from 0.005 to 0.995. Optionally, the ratio between the size of the third protruding structure 338 along the Z direction and the size of the first functional layer 316 along the Z direction ranges from 0.15 to 0.35.

[0074] Here, the first functional layer 316 has two surfaces oppositely arranged along the Z direction, the surface of the first functional layer 316 close to the substrate 302 contacts the piezoelectric layer 312, and the surface of the first functional layer 316 away from the substrate 302 contacts the second electrode layer 314. Figure 3 As shown, part of the surface of the first functional layer 316 close to the substrate 302 is the third rough surface 334. Since this surface contacts the piezoelectric layer 312, the third recessed structure 336 in the third rough surface 334 and the third protruding structure 338 in the surface of the piezoelectric layer 312 away from the substrate 302 form complementary shapes. In other words, the recessed part in the third rough surface 334 corresponds to the protruding part in the piezoelectric layer 312.

[0075] Exemplarily, forming the third rough surface 334 can include the following steps: the uneven topography can be formed on part of the surface of the piezoelectric layer 312 away from the substrate 302 by a surface treatment process; subsequently, the first functional layer 316 is deposited, and the corresponding positions in the first functional layer 316 will also replicate this uneven topography, and the corresponding positions in the surface of the first functional layer 316 close to the substrate 302 and away from the substrate 302 will both form uneven topography; subsequently, the second electrode layer 314 is deposited, and the corresponding positions in the second electrode layer 314 will also replicate this uneven topography, and the corresponding positions in the surface of the second electrode layer 314 close to the substrate 302 and away from the substrate 302 will both form uneven topography; subsequently, the frequency correction layer 320 is deposited, and the corresponding positions in the frequency correction layer 320 will also replicate this uneven topography, and the corresponding positions in the surface of the frequency correction layer 320 close to the substrate 302 and away from the substrate 302 will both form uneven topography.Figure 3 In the figure, the uneven topography formed by the first functional layer 316 away from the corresponding position in the surface of the substrate 302, the second electrode layer 314 close to the surface of the substrate 302 and away from the corresponding position in the surface of the substrate 302, and the tuning layer 320 close to the surface of the substrate 302 and away from the corresponding position in the surface of the substrate 302 is omitted, which does not constitute a limitation to the protection scope of the present disclosure.

[0076] Here, the uneven topography can also be formed on the entire surface of the first functional layer 316 close to the substrate 302 through a surface treatment process. The present disclosure does not have special limitations on the specific position of the third rough surface 334 in the surface of the first functional layer 316 close to the substrate 302. In the present embodiment, the uneven third rough surface 334 obtained through the surface treatment process is composed of repeated grooves and protrusions.

[0077] In some embodiments, at least part of the surface of the second functional layer 318 close to the substrate 302 has a fourth rough surface 340. The fourth recess structure 342 in the fourth rough surface 340 of the second functional layer 318 and the fourth protrusion structure 344 in the surface of the piezoelectric layer 312 away from the substrate 302 are in corresponding contact; wherein the ratio between the size of the fourth protrusion structure 344 and the second functional layer 318 in the Z direction is in the range of 0.005 to 0.995. Optionally, the ratio between the size of the fourth protrusion structure 344 and the second functional layer 318 in the Z direction is in the range of 0.15 to 0.35.

[0078] Here, the second functional layer 318 has two surfaces arranged in opposite directions in the Z direction, the surface of the second functional layer 318 close to the substrate 302 is in contact with the piezoelectric layer 312, and the surface of the second functional layer 318 away from the substrate 302 is in contact with the tuning layer 320. The surface of the second functional layer 318 close to the substrate 302 is a fourth rough surface 340. Figure 3 In the figure, the second functional layer 318 is enlarged, and part of the surface of the second functional layer 318 close to the substrate 302 is a fourth rough surface 340. Since this surface is in contact with the piezoelectric layer 312, the fourth recess structure 342 in the fourth rough surface 340 and the fourth protrusion structure 344 in the surface of the piezoelectric layer 312 away from the substrate 302 form complementary shapes. In other words, the recessed part in the fourth rough surface 340 corresponds to the protruding part in the piezoelectric layer 312.

[0079] Exemplarily, forming the fourth rough surface 340 can include the following steps: a surface treatment process can be used to form a rough morphology on the surface of the piezoelectric layer 312 away from the substrate 302; a second functional layer 318 is subsequently deposited, and the corresponding positions in the second functional layer 318 also replicate the rough morphology, and the corresponding positions in the surface of the second functional layer 318 close to the substrate 302 and the surface of the second functional layer 318 away from the substrate 302 both form a rough morphology; a frequency correction layer 320 is subsequently deposited, and the corresponding positions in the frequency correction layer 320 also replicate the rough morphology, and the corresponding positions in the surface of the frequency correction layer 320 close to the substrate 302 and the surface of the frequency correction layer 320 away from the substrate 302 both form a rough morphology. Figure 3 In the drawings, the rough morphologies formed on the corresponding positions in the surface of the second functional layer 318 away from the substrate 302 and the corresponding positions in the surface of the frequency correction layer 320 close to the substrate 302 and away from the substrate 302 are omitted, which do not constitute a limitation on the protection scope of the present disclosure.

[0080] Here, a surface treatment process can also be used to form a rough morphology on the entire surface of the second functional layer 318 close to the substrate 302. The present disclosure does not have special limitations on the specific positions of the fourth rough surface 340 in the surface of the second functional layer 318 close to the substrate 302. In the present embodiment, the rough fourth rough surface 340 obtained through the surface treatment process is composed of repeated grooves and protrusions.

[0081] In some embodiments, the surface treatment process for forming the first rough surface 222, the second rough surface 228, the third rough surface 334, and the fourth rough surface 340 can include, but is not limited to, ion bombardment and etching.

[0082] In some embodiments, the resonator can include at least one of the first rough surface, the second rough surface, the third rough surface, and the fourth rough surface.

[0083] In the embodiments of the present disclosure, the first rough surface, the second rough surface, the third rough surface, and the fourth rough surface, as rough reflection surfaces, can scatter the transverse wave or the miscellaneous wave, thereby effectively dissipating the energy of the transverse wave or the miscellaneous wave, avoiding the transverse wave or the miscellaneous wave from returning to the resonance region, reducing the interference of the transverse wave or the miscellaneous wave on the normal resonance acoustic wave, thereby reducing the energy loss of the normal resonance acoustic wave of the resonator, and further improving the Q value of the resonator.

[0084] Here, limiting the range of the ratio between the thickness of the first protrusion structure (or, the third protrusion structure) and the thickness of the first functional layer to within the aforementioned limited thickness ratio range, and limiting the range of the ratio between the thickness of the second protrusion structure (or, the fourth protrusion structure) and the thickness of the second functional layer to within the aforementioned limited thickness ratio range, can further reduce the energy loss of the normal resonant sound wave of the resonator, thereby improving the Q value of the resonator.

[0085] refer to Figure 4 , Figure 4 This is a cross-sectional view of the resonator provided in the fourth embodiment of this utility model. Figure 4 As shown, this utility model provides a resonator 400, which includes: a substrate 402; a reflective structure 404, a first electrode layer 406, a piezoelectric layer 412, and a second electrode layer 414 sequentially stacked on the substrate 402, wherein the overlapping area of ​​the reflective structure 404, the first electrode layer 406, the piezoelectric layer 412, and the second electrode layer 414 along the Z direction is a resonant region 408, and the other areas are non-resonant regions 410; a first functional layer 416 disposed between the piezoelectric layer 412 and the second electrode layer 414, at least a portion of the first functional layer 416 being disposed in the non-resonant region 410; a second functional layer 418 disposed on the surface of the piezoelectric layer 412 not covered by the second electrode layer 414; and a frequency-correcting layer 420 disposed on the surfaces of the second electrode layer 414 and the second functional layer 418 away from the substrate 402.

[0086] In some embodiments, the substrate 402 includes a first portion 402a that contacts the reflective structure 404 and a second portion 402b that does not contact the reflective structure 404, wherein the thickness of the first portion 402a is greater than the thickness of the second portion 402b.

[0087] Here, a portion of the substrate is etched so that the thickness of the second portion 402b of the substrate is less than the thickness of the first portion 402a of the substrate. This increases the contact area between the first electrode layer 406 and the substrate 402 (more specifically, the second portion 402b of the substrate), as well as the contact area between the piezoelectric layer 412 and the substrate 402 (more specifically, the second portion 402b of the substrate), thereby facilitating rapid heat dissipation of the resonator 400.

[0088] In some embodiments, the ratio between the difference between the thickness of the first portion 402a of the substrate and the thickness of the second portion 402b of the substrate and the dimension of the reflective structure 404 along the Z direction ranges from 0.01 to 0.2; alternatively, the ratio ranges from 0.07 to 0.1.

[0089] Here, the ratio between the difference between the thickness of the first portion 402a of the substrate and the thickness of the second portion 402b of the substrate and the thickness of the reflection structure 404 is within the above-mentioned defined thickness range, which can enhance the heat dissipation effect while ensuring the performance of the resonator 400.

[0090] In some embodiments, the resonator 400 further comprises a heat-conducting structure 446 disposed in the second portion 402b of the substrate, the heat-conducting structure 446 being in contact with the first electrode layer 406.

[0091] Here, the heat-conducting structure 446 is disposed in the second portion 402b of the substrate, the first electrode layer 406 has two surfaces oppositely arranged along the Z direction, the top surface of the first electrode layer 406 is in contact with the piezoelectric layer 412, and the bottom surface of the first electrode layer 406 is in contact with the heat-conducting structure 446. The heat-conducting structure 446 can be made of, for example, a metal heat-conducting material, which is conducive to further enhancing the heat dissipation effect of the resonator 400.

[0092] In some embodiments, the resonator 400 comprises a Film Bulk Acoustic Resonator (FBAR) or a Solidly Mounted Resonator (SMR).

[0093] Here, when the reflection structure 404 is a cavity, the resonator 400 is an FBAR; and when the reflection structure 404 is a Bragg reflection structure, the resonator 400 is an SMR.

[0094] Reference Figure 5 , Figure 5 A block diagram of an acoustic wave device is provided in the present application. As shown in Figure 5 The acoustic wave device 500 comprises at least one resonator 502 as in the above technical solutions.

[0095] In some embodiments, the acoustic wave device 500 can comprise a filter, a duplexer, and a multiplexer.

[0096] Here, the filter can comprise at least one resonator, and the resonator can be coupled to the filter in series or in parallel. The higher the Qs value of the parallel resonator or the Qp value of the series resonator in the filter, the better the overall out-of-band rejection effect of the filter, and the higher the Qp value of the parallel resonator or the Qs value of the series resonator, the smaller the overall loss of the filter. Wherein, the Qs value refers to the Q value of the resonator at the resonance frequency, and the Qp value refers to the Q value of the resonator at the anti-resonance frequency.

[0097] Here, the diplexer can include at least two filters, one filter as a transmitting filter transmitting the acoustic wave signal, and the other filter as a receiving filter receiving the acoustic wave signal.

[0098] Here, the multiplexer can include at least one diplexer and at least one filter.

[0099] The utility model provides a resonator and acoustic wave device. The resonator comprises: a substrate; a reflection structure, a first electrode layer, a piezoelectric layer and a second electrode layer which are sequentially stacked on the substrate, the reflection structure, the first electrode layer, the piezoelectric layer and the second electrode layer are a resonance area along the overlapping area in the direction perpendicular to the substrate; a first functional layer between the piezoelectric layer and the second electrode layer, at least part of the first functional layer is arranged in the non-resonance area; a second functional layer on the surface of the piezoelectric layer not covered by the second electrode layer; wherein, at least part of the first functional layer and / or at least part of the second functional layer decrease along the direction away from the resonance area along the size in the direction perpendicular to the substrate; a frequency correction layer on the surface of the second electrode layer and the second functional layer away from the substrate. In the embodiment of the utility model, at least part of the first functional layer and / or at least part of the second functional layer decrease along the direction away from the resonance area along the size in the direction perpendicular to the substrate, which can reduce the interference of the transverse wave or the miscellaneous wave on the normal resonance acoustic wave, thereby reducing the energy loss of the normal resonance acoustic wave of the resonator, and improving the Q value of the resonator.

[0100] It should be understood that the "one embodiment" or "an embodiment" mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the utility model. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily mean the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in various embodiments of the utility model, the size of the sequence number of each process does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiment of the utility model. The sequence number of the above embodiment of the utility model is only for description, not representing the pros and cons of the embodiment.

[0101] The above only describes the preferred embodiments of the utility model, and does not limit the patent scope of the utility model, and any equivalent structural transformation made by using the contents of the utility model specification and drawings, or direct / indirect application in other related technical fields is included in the patent protection scope of the utility model.

Claims

1. A resonator, characterized by, The resonator comprises: a substrate; a reflection structure, a first electrode layer, a piezoelectric layer and a second electrode layer are sequentially stacked on the substrate, and the overlapping area of the reflection structure, the first electrode layer, the piezoelectric layer and the second electrode layer in the direction perpendicular to the substrate is a resonant area; a first functional layer is arranged between the piezoelectric layer and the second electrode layer, and at least part of the first functional layer is arranged in a non-resonant area; a second functional layer is arranged on the surface of the piezoelectric layer not covered by the second electrode layer; wherein the size of at least part of the first functional layer and / or at least part of the second functional layer in the direction perpendicular to the substrate decreases in the direction away from the resonant area; a frequency correction layer is arranged on the surface of the second electrode layer and the second functional layer away from the substrate.

2. The resonator of claim 1, wherein At least part of the surface of the first functional layer away from the substrate has a first rough surface; and / or, at least part of the surface of the second functional layer away from the substrate has a second rough surface.

3. The resonator of claim 2, wherein, The first recess structure in the first rough surface of the first functional layer and the first protruding structure on the surface of the second electrode layer close to the substrate are in corresponding contact; wherein the ratio between the size of the first protruding structure and the first functional layer in the direction perpendicular to the substrate ranges from 0.005 to 0.995; and / or, The second recess structure in the second rough surface of the second functional layer and the second protruding structure on the surface of the frequency correction layer close to the substrate are in corresponding contact; wherein the ratio between the size of the second protruding structure and the second functional layer in the direction perpendicular to the substrate ranges from 0.005 to 0.

995.

4. The resonator according to any one of claims 1 to 3, characterized in that, At least part of the surface of the first functional layer close to the substrate has a third rough surface; and / or, at least part of the surface of the second functional layer close to the substrate has a fourth rough surface.

5. The resonator of claim 4, wherein, The third recess structure in the third rough surface of the first functional layer and the third protruding structure on the surface of the piezoelectric layer away from the substrate are in corresponding contact; wherein the ratio between the size of the third protruding structure and the first functional layer in the direction perpendicular to the substrate ranges from 0.005 to 0.995; and / or, The fourth recess structure in the fourth rough surface of the second functional layer and the fourth protruding structure on the surface of the piezoelectric layer away from the substrate are in corresponding contact; wherein the ratio between the size of the fourth protruding structure and the second functional layer in the direction perpendicular to the substrate ranges from 0.005 to 0.

995.

6. The resonator of claim 1, wherein When at least part of the first functional layer decreases in the size in the direction perpendicular to the substrate in the direction away from the resonant area, the included angle between the surface of the part of the first functional layer farthest from the resonant area and the substrate ranges from 3 degrees to 60 degrees; When at least part of the second functional layer decreases in the size in the direction perpendicular to the substrate in the direction away from the resonant area, the included angle between the surface of the part of the second functional layer farthest from the resonant area and the substrate ranges from 3 degrees to 60 degrees.

7. The resonator of claim 6, wherein an angle between a surface of the portion of the first functional layer farthest from the resonant region and the substrate ranges from 20 degrees to 45 degrees when a dimension of the at least a portion of the first functional layer in a direction perpendicular to the substrate direction decreases in a direction away from the resonant region; an angle between a surface of the portion of the second functional layer farthest from the resonant region and the substrate ranges from 20 degrees to 45 degrees when a dimension of the at least a portion of the second functional layer in a direction perpendicular to the substrate direction decreases in a direction away from the resonant region.

8. The resonator of claim 1, wherein a ratio between a minimum dimension and a maximum dimension of the first functional layer in a direction perpendicular to the substrate direction ranges from 0.005 to 0.995 when a dimension of the at least a portion of the first functional layer in a direction perpendicular to the substrate direction decreases in a direction away from the resonant region; a ratio between a minimum dimension and a maximum dimension of the second functional layer in a direction perpendicular to the substrate direction ranges from 0.005 to 0.995 when a dimension of the at least a portion of the second functional layer in a direction perpendicular to the substrate direction decreases in a direction away from the resonant region.

9. The resonator of claim 8, wherein, a ratio between a minimum dimension and a maximum dimension of the first functional layer in a direction perpendicular to the substrate direction ranges from 0.75 to 0.95 when a dimension of the at least a portion of the first functional layer in a direction perpendicular to the substrate direction decreases in a direction away from the resonant region; a ratio between a minimum dimension and a maximum dimension of the second functional layer in a direction perpendicular to the substrate direction ranges from 0.75 to 0.95 when a dimension of the at least a portion of the second functional layer in a direction perpendicular to the substrate direction decreases in a direction away from the resonant region.

10. The resonator of claim 1, wherein, the substrate includes a first portion in contact with the reflective structure and a second portion not in contact with the reflective structure, a thickness of the first portion of the substrate is greater than a thickness of the second portion of the substrate.

11. The resonator of claim 10, wherein, a ratio between a difference between the thickness of the first portion of the substrate and the thickness of the second portion of the substrate and a dimension of the reflective structure in a direction perpendicular to the substrate direction ranges from 0.01 to 0.

2.

12. The resonator of claim 11, wherein, a ratio between a difference between the thickness of the first portion of the substrate and the thickness of the second portion of the substrate and a dimension of the reflective structure in a direction perpendicular to the substrate direction ranges from 0.07 to 0.

1.

13. The resonator of claim 1, wherein, the resonator further comprises: a thermally conductive structure disposed in the second portion of the substrate, the thermally conductive structure in contact with the first electrode layer.

14. The resonator of claim 1, wherein, an acoustic impedance of the first functional layer material is less than or equal to an acoustic impedance of air, an acoustic impedance of the second functional layer material is less than or equal to an acoustic impedance of air.

15. An acoustic wave device, characterized by, the acoustic wave device comprises at least one resonator as claimed in any one of claims 1 to 14.

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