Bulk acoustic wave resonator, filter and electronic device provided with an insertion structure and a temperature compensation layer

Abstract

The present application relates to a bulk acoustic wave resonator, comprising: a substrate; an acoustic mirror; a bottom electrode; a top electrode; a piezoelectric layer, a temperature compensation layer, wherein: the area where the acoustic mirror, the bottom electrode, the piezoelectric layer, the top electrode overlap in the thickness direction of the substrate is the effective area of the resonator; the piezoelectric layer is provided with a composite insertion structure arranged along the edge of the effective area, the composite insertion structure comprises a first insertion layer and a second insertion layer, at least a part of the first insertion layer overlaps with the effective area in the top view of the resonator, and the first insertion layer and the second insertion layer at least partially overlap in the top view of the resonator; the first insertion layer is a metal material and the second insertion layer is air or a dielectric material, or the first insertion layer is a dielectric material and the second insertion layer is air, at least a part of the temperature compensation layer is located in the effective area in the top view of the resonator, and the material of the temperature compensation layer is a material opposite to the frequency temperature coefficient of the piezoelectric layer. The present application also relates to a filter and an electronic device.

Description

Technical Field

[0001] Embodiments of the present invention relate to the field of semiconductors, and in particular to a bulk acoustic wave resonator, a filter, and an electronic device having one of the above components. Background Art

[0002] BAW filters offer advantages such as low insertion loss, high squareness, and high power handling. Therefore, they are widely used in modern wireless communication systems and are crucial components for determining the quality of RF signals entering and exiting the communication system. The performance of a BAW filter is determined by the BAW resonator (BAW) that constitutes it. For example, the resonant frequency of the BAW resonator determines the filter's operating frequency, the effective electromechanical coupling coefficient determines the filter's bandwidth, and the quality factor determines the filter's insertion loss. Given a given filter structure, its quality factor, particularly at the series and parallel resonant frequencies (or series-parallel impedance), significantly impacts the passband insertion loss. Therefore, improving the resonator's quality factor is a key issue in high-performance filter design. The quality factor (Qs) or series impedance (Rs) at the BAW resonator's series resonant frequency is typically determined by electrode losses and material losses, while the quality factor (Qp) or parallel impedance (Rp) at the BAW resonator's parallel resonant frequency is typically affected by boundary acoustic wave leakage. Therefore, when the resonator material and stacking structure are determined, there is limited room for improving Qs (or Rs), but the boundary leakage of the sound wave can be effectively improved by changing the boundary structure of the resonator, thereby significantly improving the Qp (or Rp) of the resonator.

[0003] The cross-sectional structure diagram of the composite insertion type thin film bulk acoustic resonator is as follows Figure 1 As shown in the figure. On the one hand, the insertion layer set in the piezoelectric layer is located at the position where the stress of the resonator piston mode is the largest, so the impedance mismatch generated has a stronger sound wave reflection effect. On the other hand, because the insertion layer set in the piezoelectric layer can extend into the inactive area, the boundary impedance mismatch characteristics between the active area and the inactive area are enhanced, thereby reflecting more waves back to the effective resonance area, which is manifested in an improved Rp in terms of electrical performance.

[0004] However, as the operating temperature changes, Figure 1 The resonant frequency of the resonator shown will drift, and this temperature drift phenomenon limits the practical application of the composite insertion resonator. Summary of the Invention

[0005] The present invention is proposed to suppress the temperature drift phenomenon of a composite insertion type bulk acoustic wave resonator and improve the temperature stability of the bulk acoustic wave resonator.

[0006] According to an aspect of the embodiments of the present application, a bulk acoustic wave resonator is provided, which is provided with a composite insertion structure having a first insertion layer and a second insertion layer, and is also provided with a temperature compensation layer. Accordingly, the bulk acoustic wave resonator includes:

[0007] a substrate;

[0008] an acoustic mirror;

[0009] a bottom electrode;

[0010] a top electrode;

[0011] a piezoelectric layer;

[0012] a temperature compensation layer,

[0013] wherein:

[0014] an area in which the acoustic mirror, the bottom electrode, the piezoelectric layer, and the top electrode overlap in a thickness direction of the substrate is an effective area of the resonator;

[0015] the piezoelectric layer is provided with a composite insertion structure arranged along an edge of the effective area, the composite insertion structure includes a first insertion layer and a second insertion layer, at least a portion of the first insertion layer overlaps the effective area in a plan view of the resonator, the first insertion layer at least partially overlaps the second insertion layer in the plan view of the resonator, the first insertion layer is a metal material and the second insertion layer is air or a dielectric material, or the first insertion layer is a dielectric material and the second insertion layer is air; and

[0016] at least a portion of the temperature compensation layer is located within the effective area in the plan view of the resonator, and a material of the temperature compensation layer is a material opposite to a frequency temperature coefficient of the piezoelectric layer.

[0017] According to still another aspect of the embodiments of the present application, a filter is provided, which includes the above-described resonator.

[0018] According to yet another aspect of the embodiments of the present application, an electronic device is provided, which includes the above-described resonator, or the above-described filter. BRIEF DESCRIPTION OF DRAWINGS

[0019] The following description and drawings can better help understand these and other features and advantages of the various embodiments of the present application disclosed, in which the same reference signs refer to the same components throughout the drawings in which:

[0020] Figure 1 schematic cross-sectional view of a composite insertion type bulk acoustic wave resonator;

[0021] Figure 2schematic top view of a bulk acoustic wave resonator according to an exemplary embodiment of the present application;

[0022] Figure 3 schematic cross-sectional view taken along the A-O-A line in Figure 2

[0023] Figure 4 schematic cross-sectional view taken along the A-O-A line in Figure 2

[0024] Figure 5 schematic cross-sectional view taken along the A-O-A line in Figure 2

[0025] Figure 6 schematic cross-sectional view taken along the A-O-A line in Figure 2

[0026] Figure 7 schematic cross-sectional view taken along the A-O-A line in Figure 2

[0027] Figure 8 schematic cross-sectional view taken along the A-O-A line in Figure 2

[0028] Figure 9 schematic cross-sectional view taken along the A-O-A line in Figure 2

[0029] Figure 10 schematic cross-sectional view of a temperature compensating layer structure according to an exemplary embodiment of the present application;

[0030] Figure 11 schematic cross-sectional view of a temperature compensating layer structure according to another exemplary embodiment of the present application;

[0031] Figure 12 schematic cross-sectional view of a temperature compensating layer structure according to another exemplary embodiment of the present application;

[0032] Figures 13-17 schematic cross-sectional view of a bulk acoustic wave resonator schematically illustrating an arrangement between a first interposer layer and a second interposer layer;

[0033] Figure 18 schematic top view of a bulk acoustic wave resonator according to an exemplary embodiment of the present application;​​​​​​​

[0034] Figure 19 schematic partial cross-sectional view taken along the O-A line in FIG. 6A, showing the positional relationship between the first interposer layer and the second interposer layer, but not showing the temperature compensating layer; Figure 18

[0035] Figure 20 schematic view showing the setting position of the interposer protrusion in the thickness direction of the piezoelectric layer according to an example embodiment of the present application;

[0036] Figure 21 schematic partial cross-sectional view taken along the O-A line in FIG. 6A, showing the positional relationship between the first interposer layer and the second interposer layer, but not showing the temperature compensating layer; Figure 18

[0037] Figure 22 schematic partial cross-sectional view taken along the O-B line in FIG. 6B, showing the positional relationship between the first interposer layer and the second interposer layer, but not showing the temperature compensating layer according to another example embodiment of the present application; Figure 18

[0038] Figure 23 schematic partial cross-sectional view taken along the O-B line in FIG. 6B, showing the positional relationship between the first interposer layer and the second interposer layer, but not showing the temperature compensating layer according to another example embodiment of the present application; Figure 18

[0039] Figure 24 schematic partial cross-sectional view taken along the O-B line in FIG. 6B, showing the positional relationship between the first interposer layer and the second interposer layer, but not showing the temperature compensating layer according to another example embodiment of the present application; Figure 18

[0040] Figure 25 schematic plan view of a bulk acoustic wave resonator according to an example embodiment of the present application;

[0041] Figure 26 schematic partial cross-sectional view taken along the O-A line in FIG. 6A, showing the positional relationship between the first interposer layer and the second interposer layer, but not showing the temperature compensating layer according to an example embodiment of the present application; Figure 25

[0042] schematic partial cross-sectional view taken along the O-B line in FIG. 6B, showing the positional relationship between the first interposer layer and the second interposer layer, but not showing the temperature compensating layer according to an example embodiment of the present application; Figure 27 Figure 25 schematic partial cross-sectional view taken along the O-B line in FIG. 6B, showing the positional relationship between the first interposer layer and the second interposer layer, but not showing the temperature compensating layer according to an example embodiment of the present application;​​​​​​

[0043] Figure 28 schematic partial cross-sectional view taken along the O-B line in FIG. 1A, showing the positional relationship between the first and second insertion layers, but not showing the temperature compensating layer; Figure 25

[0044] Figure 29 schematic partial cross-sectional view taken along the O-B line in FIG. 1A, showing the positional relationship between the first and second insertion layers, but not showing the temperature compensating layer; Figure 25

[0045] Figure 30 schematic partial cross-sectional view of a bulk acoustic wave resonator according to an example embodiment of the present application, taken at a position similar to the O-A line in FIG. 1A, showing the positional relationship between the first and second insertion layers, but not showing the temperature compensating layer; Figure 18

[0046] Figure 31 schematic partial cross-sectional view of a bulk acoustic wave resonator according to an example embodiment of the present application, taken at a position similar to the O-A line in FIG. 1A, showing the positional relationship between the first and second insertion layers, but not showing the temperature compensating layer. Figure 18 DETAILED DESCRIPTION

[0047] The technical solutions of the present application will be further described below by way of examples, with reference to the accompanying drawings. The following description of the embodiments of the present application with reference to the accompanying drawings is intended to explain the general inventive concept of the present application, and should not be construed as limiting the present application in any way.

[0048] Figure 2 schematic plan view of a bulk acoustic wave resonator according to an example embodiment of the present application. As shown in FIG. 1B, the bulk acoustic wave resonator includes an acoustic mirror, a bottom electrode, a piezoelectric layer, and a top electrode, and the overlapping region of the four components in the thickness direction of the resonator defines the effective region of the resonator. The letter O represents the center of the resonator. Figure 2

[0049] Figures 3-5 schematic cross-sectional views taken along the A-O-A line in FIG. 1A, in which the relative positions of the composite insertion layer and the temperature compensating layer in the lateral direction or horizontal direction are shown. Figure 2

[0050] schematic cross-sectional view taken along the A-O-A line in FIG. 1A according to an example embodiment of the present application. The following will specifically describe Figure 3 Figure 2 Figure 3 ​​​​​​​The structure of the resonator in the present application. Figure 3 The structure of the resonator in the present application.

[0051] 10: Substrate. The material can be selected from single crystal silicon, quartz, gallium arsenide, sapphire, etc.

[0052] 20: Acoustic mirror. The acoustic mirror is located on the upper surface of the substrate or embedded in the substrate. Figure 3 The acoustic mirror is a cavity embedded in the substrate in the present application, but any other acoustic mirror structure such as Bragg reflector is also applicable.

[0053] 30: First bottom electrode. The bottom electrode 30 is deposited on the upper surface of the acoustic mirror and covers the acoustic mirror. The edge of the bottom electrode 30 can be etched into a bevel and located at the outer edge of the acoustic mirror, in addition to being stepped, vertical or other similar structures. The second end (outer end, in the present application, for all components, the side away from the center of the effective area in the radial direction or transverse direction is outer) of the bottom electrode is d19 away from the acoustic mirror, and d19 ranges from 0 to 10 μm. The material can be gold (Au), tungsten (W), molybdenum (Mo), platinum (Pt), ruthenium (Ru), iridium (Ir), titanium tungsten (TiW), aluminum (Al), titanium (Ti), osmium (Os), magnesium (Mg), gold (Au), tungsten (W), molybdenum (Mo), platinum (Pt), ruthenium (Ru), iridium (Ir), germanium (Ge), copper (Cu), aluminum (Al), chromium (Cr), arsenic-doped gold, etc.

[0054] 31: Second bottom electrode. The material of the second bottom electrode can be the same as the first bottom electrode 30.

[0055] 40: First piezoelectric layer. The piezoelectric layer material can be aluminum nitride (AlN), doped ALN, zinc oxide (ZnO), lead zirconate titanate (PZT), lithium niobate (LiNbO3), quartz, potassium niobate (KNbO3), or lithium tantalate (LiTaO3), etc. The doped ALN 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), and lutetium (Lu).

[0056] 41: Second piezoelectric layer. The material of the second piezoelectric layer can be the same as the first piezoelectric layer 40.

[0057] 50: top electrode. The material of the top electrode 50 can be the same as the first bottom electrode 30. The top electrode is located inside the acoustic mirror, and the distance between the top electrode and the edge of the acoustic mirror is d14, which is in the range of 0-10 μm. A passivation layer can be coated on the top electrode. The passivation layer includes but is not limited to SiO2, Si3N4, ALN, etc.

[0058] 60, 61: first ring-shaped insertion layer. The insertion layer 60 has a first end (inner end, in the present invention, for all components, the side close to the center of the active area in the radial direction or the transverse direction is the inner side) and a second end: the first end of the insertion layer 60 is located inside the active area, and the distance between the first end of the insertion layer 60 and the first end of the second ring-shaped insertion layer 70 is d11, which is in the range of 0-10 μm; the second end of the insertion layer 60 should exceed the first end of the second ring-shaped insertion layer 70 and can further extend outward. The insertion layer 61 has a first end and a second end: the first end of the insertion layer 61 is located inside the active area, and the distance between the first end of the insertion layer 61 and the first end of the second ring-shaped insertion layer 70 is d17, which is in the range of 0-10 μm; the second end of the insertion layer 61 should exceed the first end of the second ring-shaped insertion layer 70 and can further extend outward. In the present embodiment, the second end of the insertion layer 61 extends outward until exceeding the edge of the bottom electrode. The height of the first ring-shaped insertion layer is in the range of The material of the first ring-shaped insertion layer can be metal, and the material of the metal is the same as the first bottom electrode 30.

[0059] 70, 71: second ring-shaped insertion layer. The second ring-shaped insertion layer 70 has a first end and a second end: the first end of the second ring-shaped insertion layer 70 is located inside the active area, and the distance between the first end of the second ring-shaped insertion layer 70 and the first end of the top electrode is d12, which is in the range of 0-10 μm; the second end of the second ring-shaped insertion layer 70 should exceed the edge of the top electrode and can further extend outward. In the present embodiment, the second end of the second ring-shaped insertion layer 70 extends to the outside of the edge of the acoustic mirror. The second ring-shaped insertion layer 71 has a first end and a second end: the first end of the second ring-shaped insertion layer 71 is located inside the active area, and the distance between the first end of the second ring-shaped insertion layer 71 and the edge of the acoustic mirror is d18, which is in the range of 0-10 μm; the second end of the second ring-shaped insertion layer 71 preferably exceeds the edge of the bottom electrode and can further extend outward. In the present embodiment, the second end of the second ring-shaped insertion layer 71 extends outward until exceeding the edge of the bottom electrode, and the distance between the second end of the second ring-shaped insertion layer 71 and the bottom electrode is d20, which is in the range of 0-20 μm. The height of the second ring-shaped insertion layer 71 is in the range of The material of the second annular insertion layer 71 can be dielectric or air. The dielectric material can be one or more of or a combination of SiO2, Si3N4, SiC, AlN, doped ALN, Al2O3, porous silicon, fluorinated amorphous carbon, fluoropolymers, parylene, polyarylether, hydrogensilsesquioxane, crosslinked polystyrene polymers, biphenyl cyclobutene, fluorinated silicon dioxide, carbon-doped oxide, and diamond, or air. The first annular insertion layer and the second annular insertion layer together form a composite annular insertion layer. The horizontal center of the composite annular insertion layer is located between 1 / 3 and 2 / 3 of the thickness direction of the entire piezoelectric material, for example, see Figure 20 When the first annular insertion layer is dielectric or air, the second annular insertion layer can be metal; or when the first annular insertion layer is metal, the second annular insertion layer can be dielectric or air; or both are metal; or both are dielectric or air.

[0060] 80: temperature compensation layer. In Figure 3 , the temperature compensation layer is disposed above the first bottom electrode in the thickness direction and between the composite insertion layers in the lateral direction, as shown in the area L1. The material of the temperature compensation layer is a material opposite to the frequency-temperature coefficient of the piezoelectric layer, including but not limited to SiO2, doped SiO2, etc.

[0061] The temperature compensation layer structure can only set the temperature compensation layer, or can be other structures. For example, as Figure 10 shown, a cutoff layer 95 can be disposed below the temperature compensation layer 80, which ensures the protection of the bottom electrode during the process of making the temperature compensation layer 80, and can further improve the temperature compensation effect. The material of the cutoff layer can be ALN, Si3N4, etc. A passivation layer 96 can be disposed above the temperature compensation layer 80, which can ensure the growth quality of the second bottom electrode and the piezoelectric layer, and can further improve the temperature compensation effect. The material of the passivation layer can be ALN, Si3N4, etc.

[0062] In Figure 3In the embodiment shown, on the one hand, the composite annular insertion layer provided in the piezoelectric layer is located at the position where the stress of the resonator piston mode is the largest, so the resulting impedance mismatch has a stronger sound wave reflection effect. On the other hand, since the insertion layer provided in the piezoelectric layer can extend into the ineffective area, the boundary impedance mismatch characteristics between the effective area and the ineffective area are enhanced, thereby reflecting more sound waves back to the effective resonance area, which is manifested in an improved Rp in terms of electrical performance. However, the resonant frequency of the device containing the composite annular insertion layer will drift with temperature changes. Since the frequency temperature coefficient of the temperature compensation layer is opposite to that of the piezoelectric material, it can be used to adjust the temperature drift characteristics of the composite annular insertion type device. The frequency temperature characteristics of the entire device can be adjusted by designing the thickness of the temperature compensation layer. When designing the thickness of the temperature compensation layer, two factors need to be considered: one is the mass load effect of the temperature compensation layer, and the other is the temperature compensation effect of the temperature compensation layer. These two factors affect each other. When the temperature compensation layer is introduced, it is equivalent to introducing a mass load layer, which reduces the original resonant frequency. Therefore, the thickness of the piezoelectric layer and the electrode layer needs to be appropriately thinned so that the frequency rises to the target value. At the same time, the ratio of the thickness of the piezoelectric layer and the electrode layer to the thickness of the temperature compensation layer will affect the frequency temperature coefficient of the final device.

[0063] Figure 4 According to another exemplary embodiment of the present invention, Figure 2 Schematic cross-sectional view taken along the AOA line in FIG. Figure 4 The embodiment shown and Figure 3 The embodiments shown are similar, and the same reference numerals indicate the same parts. Figure 4 and Figure 3 The difference is: Figure 4 In the horizontal direction, the temperature compensation layer 80 is located between the single insertion layers, such as the area shown by L2. More specifically, Figure 4 In the figure, the temperature compensating layer is located between the insertion layers 70 and 71 in the lateral direction, and in the top view of the resonator, both ends of the temperature compensating layer overlap with the insertion layers 60 and 61.

[0064] Figure 5 According to another exemplary embodiment of the present invention, Figure 2 Schematic cross-sectional view taken along the AOA line in FIG. Figure 5 The embodiment shown and Figure 3 The embodiments shown are similar, and the same reference numerals indicate the same parts. Figure 5 and Figure 3 The difference is: Figure 5 In the horizontal direction, the position of the temperature compensation layer 80 is shown in the area L3. More specifically, Figure 5 In the top view of the resonator, both ends of the temperature compensation layer overlap with the insertion layers 60 and 61 as well as the insertion layers 70 and 71 .

[0065] It should be specially pointed out that the positional relationship between the temperature compensation layer and the composite insertion layer in the transverse direction or horizontal direction is not limited to Figures 3-5 the above, and other ways are also possible, as long as at least a part of the temperature compensation layer is located within the effective area in the top view of the resonator, and are within the protection scope of the present application.

[0066] Figures 6-8 are schematic cross-sectional views taken along the A-O-A line in Figure 2 , in which the temperature compensation layer 80 and the composite insertion layer are shown, and the different positions of the temperature compensation layer 80 in the thickness direction of the resonator are shown.

[0067] Figure 6 is a schematic cross-sectional view taken along the A-O-A line in Figure 2 , according to still another exemplary embodiment of the present application. Figure 6 the embodiment shown in Figure 3 is similar to the embodiment shown in Figure 6 , like reference numerals indicate like parts, Figure 3 and the difference is that in Figure 6 , the temperature compensation layer 80 is located between the first piezoelectric layer 40 and the second piezoelectric layer 43. At this time, the temperature compensation layer 80 can be a single temperature compensation layer, or a lower cutoff layer and an upper passivation layer can be added as shown in Figure 10 , but these two structures, although they can improve the temperature drift characteristics of the resonator, will also form an additional capacitance in the resonator, ultimately affecting the electrical performance of the device. Further, as shown in Figure 11 , a metal layer 90 can be provided below the cutoff layer 95, and a metal layer 91 can be provided above the passivation layer 96, at this time, the upper and lower metal layers added outside the temperature compensation layer form a sealed metal wall, the potential of this metal wall is 0, which does not affect the electrical performance of the resonator, and can further improve the temperature drift characteristics of the composite insertion resonator.

[0068] In Figure 6 , as can be understood by those skilled in the art, the temperature compensation layer 80 can also be between the second piezoelectric layers.

[0069] Figure 7 is a schematic cross-sectional view taken along the A-O-A line in Figure 2 , according to still another exemplary embodiment of the present application. Figure 7 the embodiment shown in Figure 3 is similar to the embodiment shown in Figure 7 , like reference numerals indicate like parts, Figure 3 and the difference is that in Figure 7 , the temperature compensation layer is located above the first piezoelectric layer 40 in the thickness direction.

[0070] Figure 8According to another exemplary embodiment of the present invention Figure 2 Schematic cross-sectional view taken along the AOA line in FIG. Figure 8 The embodiment shown and Figure 3 The embodiments shown are similar, and the same reference numerals indicate the same parts. Figure 8 and Figure 3 The difference is: Figure 8 In the embodiment, the temperature compensation layer is located at the top electrode 50 in the thickness direction. In this case, the temperature compensation layer can be a separate temperature compensation layer, or a cutoff layer can be added under the temperature compensation layer without adding a passivation layer above the temperature compensation layer. Figure 12 shown.

[0071] Figure 9 According to an exemplary embodiment of the present invention Figure 2 Schematic cross-sectional view taken along the AOA line in FIG. Figure 9 The embodiment shown and Figure 3 The illustrated embodiments are similar and like reference numerals indicate like parts. Figure 9 It is shown in FIG. 4 that the first piezoelectric layer 40 and the second piezoelectric layer 41 can be made of different piezoelectric materials or the same piezoelectric material with different doping concentrations.

[0072] Figures 13-17 FIG. 1 is a schematic cross-sectional view of a bulk acoustic wave resonator exemplarily illustrating an arrangement structure between a first insertion layer and a second insertion layer. Figures 13-17 The figure schematically shows the change in the positional relationship between the first insertion layer and the second insertion layer when a temperature compensation layer is provided in the piezoelectric layer.

[0073] exist Figure 13 The resonator includes: a substrate 110, an acoustic mirror 120, a first bottom electrode 130 and a second bottom electrode 131, a first piezoelectric layer 140 and a second piezoelectric layer 141, first insertion layers 160 and 161, second insertion layers 170 and 171, a top electrode 150, and a temperature compensation layer 180. Figure 13 In the embodiment, the temperature compensation layer 180 is provided in the bottom electrode. Figure 13 The structure and Figure 3 The structure is similar to that of Figure 13 In, with Figure 3 Differently, inside the active area, the second insertion layers 170 and 171 cover the first insertion layers 160 and 161 . Figure 26 and 27 The figure also exemplarily shows a situation where one insert layer covers another insert layer.

[0074] Figure 14 The structure and Figure 13 Similarly, the same reference numerals denote Figure 13 In Figure 14, the same parts as Figure 1329 also exemplarily shows a situation where the outer end of the second insertion layer is located inside the outer end of the first insertion layer.

[0075] Figure 15 The structure and Figure 13 Similarly, the same reference numerals denote Figure 13 In Figure 15, the same parts as Figure 13 Different from the above, the composite insert layer has an aligned structure outside the effective area. Figure 28 The case of an aligned structure is also exemplified.

[0076] exist Figure 16 The resonator includes: a substrate 210, an acoustic mirror 220, a bottom electrode 230, a first piezoelectric layer 240 and a second piezoelectric layer 241, first insertion layers 260 and 261, second insertion layers 270 and 271, a top electrode 250, and a temperature compensation layer 280. Figure 16 In the embodiment, the temperature compensation layer 180 is provided in the bottom electrode. Figure 16 The structure and Figure 3 The structure is similar to that of Figure 16 In, with Figure 3 Differently, on the non-connected side, all / part of the second piezoelectric layer above the insertion layer is etched away, and the first end of the top electrode coincides with the first end of the piezoelectric layer in the thickness direction.

[0077] exist Figure 17 The resonator includes: a substrate 210, an acoustic mirror 220, a first bottom electrode 230 and a second bottom electrode 231, a first piezoelectric layer 240 and a second piezoelectric layer 241, first insertion layers 260 and 261, second insertion layers 270 and 271, a top electrode 250, and a temperature compensation layer 280. Figure 17 In the embodiment, the temperature compensation layer 180 is provided in the bottom electrode. Figure 17 The structure and Figure 3 The structure is similar to that of Figure 17 In, with Figure 3 Differently, the first end of the second insertion layer is closer to the center of the resonator than the first end of the first insertion layer.

[0078] Refer to the following Figures 18-19 21-31 describe in detail the composite insert structure and the positional relationship between the first insert layer and the second insert layer in the composite insert structure using different embodiments. Figures 18-19 21-31, the same reference numerals denote the same components. Figures 18-19 And the temperature compensation layer is not shown in 21-31. However, as those skilled in the art will understand, the temperature compensation layer can be used to refer to Figures 3-12 The corresponding setting is inFigures 18-19 and the resonator shown in Fig. 21-31.

[0079] Figure 18 Fig. 1 is a schematic top view of a bulk acoustic wave resonator according to an exemplary embodiment of the present application. As shown in Fig. 1, the bulk acoustic wave resonator includes a bottom electrode, a piezoelectric layer, a top electrode, a composite ring-shaped interposer structure, and a passivation layer on the top electrode. The composite ring-shaped interposer structure is composed of a ring-shaped interposer bump structure and a ring-shaped interposer wing structure, which appears as a ring-shaped wing structure at the non-connection edge of the bottom electrode and the top electrode, and appears as a ring-shaped bridge structure at the connection edge of the bottom electrode and the top electrode. Figure 18 In the present application, for example, in Fig. 1, the composite interposer structure is shown in a zigzag shape, but this does not mean that the actual shape must be a zigzag shape, and the edge shape of the composite interposer structure can still be a shape parallel to the edge of the top electrode.

[0080] Figure 18 It should be noted that in the present application, the interposer structure can or can not be ring-shaped, and both are within the scope of the present application.

[0081] It should be noted that in the present application, the interposer structure can or can not be ring-shaped, and both are within the scope of the present application.

[0082] Figure 19 Fig. 2 is a schematic partial cross-sectional view of the O-A line in Fig. 1 according to an exemplary embodiment of the present application. As shown in Fig. 2, the bulk acoustic wave resonator includes a substrate 100 and an acoustic mirror 110, which is located on the upper surface of the substrate or embedded in the interior of the substrate, and in Fig. 2 the acoustic mirror is composed of a cavity embedded in the substrate, but any other acoustic mirror structure such as a Bragg reflector is also applicable. The bulk acoustic wave resonator further includes a bottom electrode 120, a piezoelectric layer 130, a top electrode 140, an interposer bump 150, and an interposer wing 160, wherein the interposer bump 150 and the interposer wing 160 together form a composite interposer structure, and the top electrode 140 can include a passivation layer. The bottom electrode 120 is deposited on the upper surface of the acoustic mirror and covers the acoustic mirror. The edge of the bottom electrode 120 can be etched into a bevel, and the bevel is located outside the acoustic mirror, and in addition can be in a stepped shape, a vertical shape, or other similar structures. Figure 18 Figure 19 Figure 19 It should be noted that in the present application, the interposer structure can or can not be ring-shaped, and both are within the scope of the present application.

[0083] The area where the acoustic mirror 110, the bottom electrode 120, the piezoelectric layer 130, and the top electrode 140 overlap in the thickness direction of the resonator is the effective area of the resonator. The top electrode is located inside the acoustic mirror, and the distance between the top electrode and the edge of the acoustic mirror is d14, which is in the range of 0-10 μm. The bottom electrode is located outside the acoustic mirror, and the distance between the first end of the bottom electrode and the acoustic mirror is d13, which is in the range of 0-10 μm.

[0084] ​​​The insertion protrusion 150 has a first end and a second end, the first end is inside the effective area, and the second end can be aligned with the edge of the effective area or extend out of the effective area by a distance d15, which is in the range of 0-20 μm. The distance between the first end of the insertion protrusion 150 and the first end of the insertion wing 160 is d11, which is in the range of 0-10 μm, the height of the insertion protrusion is h1, which is in the range of

[0085] The insertion wing 160 has a first end and a second end, the first end is above the 150 in the thickness direction, and is between the edge of the effective area and the first end of the 150 in the horizontal direction, and the second end can be aligned with the edge of the effective area or extend out of the effective area by a distance d16, which is in the range of 0-20 μm. The distance between the first end of the insertion wing 160 and the edge of the top electrode 140 is d12, which is in the range of 0-10 μm, and the height of the insertion wing 160 is h2, which is in the range of

[0086] It should be specially pointed out that in the present application, for the numerical range, not only the given range end value, but also the mean or midpoint value of the numerical range can be used.

[0087] In this embodiment, the material of the insertion protrusion 150 is metal, such as Mo, W, Cu, Al, etc. The material of the insertion wing 160 is dielectric (such as SiO2, Si3N4, ALN, doped AlN with different doping concentrations than the piezoelectric layer, etc.) or air.

[0088] Figure 20 A schematic diagram showing the setting position of the insertion protrusion in the thickness direction of the piezoelectric layer according to an exemplary embodiment of the present application. More specifically, in the thickness direction of the resonator, C-C and D-D divide the piezoelectric layer into three parts, and E-E is the center horizontal line of the insertion protrusion, which needs to be located in the middle of the contour lines shown by C-C and D-D. Figure 19 In this embodiment, the insertion protrusion can be set as such, and the position of the overlapping part of the insertion protrusion and the insertion wing in the piezoelectric layer can also be set as such.

[0089] In the present application, as long as it is set between the C-C line and the D-D line, it is set in the middle position of the piezoelectric layer.

[0090] Based on Figure 19In the embodiment, on the one hand, the composite insertion layer (the insertion protrusion layer corresponding to the first insertion layer and the wing bridge layer corresponding to the second insertion layer) provided in the piezoelectric layer is located at the position where the piston mode stress of the resonator is maximum (this corresponds to a special form in which the composite insertion layer is located in the middle position of the piezoelectric layer), so the impedance mismatch generated has a stronger sound wave reflection effect; on the other hand, compared with a single insertion layer (such as a single protrusion layer), the two insertion layers provided in the piezoelectric layer can increase the impedance mismatch interface between the effective area and the ineffective area of ​​the resonator, thereby generating multiple reflections of the laterally propagating leakage waves, thereby improving the Q value of the resonator, especially improving the Q value of the resonator at the parallel resonant frequency (or the parallel resonant impedance Rp).

[0091] Figure 21 According to an exemplary embodiment of the present invention Figure 18 Schematic partial cross-sectional view taken along line OB in FIG. Figure 21 In the figure, the bottom electrode extends out of the acoustic mirror, and the distance between the edge of the bottom electrode and the acoustic mirror is d19, which ranges from 0-10μm. The insertion protrusion 150 has a first end and a second end, the first end is located inside the effective area, the second end is aligned with the acoustic mirror, the first end is at a distance d17 from the first end of the insertion bridge 161, and the range of d17 is 0-10μm. The insertion bridge 161 has a first end and a second end, the first end of the insertion bridge 161 is located above the insertion protrusion 150 in the thickness direction, the distance between the first end of the insertion bridge 161 and the edge of the acoustic mirror is d18, and the range of d18 is 0-10μm. The second end of the insertion bridge 161 extends beyond the bottom electrode, and the distance between the second end of the insertion bridge 161 and the bottom electrode is d20, and the range of d20 is 0-20μm.

[0092] Figure 22 According to another exemplary embodiment of the present invention Figure 18 Schematic partial cross-sectional view taken along line OB in FIG. Figure 22 The embodiment shown is Figure 21 The illustrated embodiment is similar except that the second end of the insertion protrusion 150 extends beyond the active area by a value d1.

[0093] Figure 23 According to another exemplary embodiment of the present invention Figure 18 Schematic partial cross-sectional view taken along line OB in FIG. Figure 23 The embodiment shown is Figure 22 The embodiment shown is similar, except that the second end of the inserted protrusion structure 150 extends beyond the edge of the bottom electrode, with an extension value d24 ranging from 0 to 10 μm. This design increases process tolerance.

[0094] Figure 24Fig. 4 is a schematic partial cross-sectional view taken along the O-B line in Fig. 3, according to another exemplary embodiment of the present application. Figure 18 Fig. 5 is a schematic partial cross-sectional view taken along the O-B line in Fig. 4, according to another exemplary embodiment of the present application. Figure 24 Fig. 6 is a schematic partial cross-sectional view taken along the O-B line in Fig. 5, according to another exemplary embodiment of the present application. Figure 19 Fig. 7 is a schematic partial cross-sectional view taken along the O-B line in Fig. 6, according to another exemplary embodiment of the present application.

[0095] Figure 25 Fig. 8 is a schematic top view of a bulk acoustic resonator according to an exemplary embodiment of the present application. In the embodiment shown in Fig. 8, the bulk acoustic resonator includes a bottom electrode, a piezoelectric layer, a top electrode, a composite ring-shaped interposer structure, the composite ring-shaped interposer structure being composed of a ring-shaped interposer bump and a ring-shaped interposer wing structure, the ring-shaped interposer wing structure exhibiting a ring-shaped wing structure at the non-connected edges of the bottom electrode and the top electrode, and exhibiting a ring-shaped bridge structure at the connected edges of the bottom electrode and the top electrode. Figure 25 Fig. 9 is a schematic partial cross-sectional view taken along the O-A line in Fig. 8, according to an exemplary embodiment of the present application. As shown in Fig. 9, the bulk acoustic resonator includes a substrate 200 and an acoustic mirror 210, the acoustic mirror being located on the upper surface of the substrate or embedded in the substrate, the acoustic mirror being composed of a cavity embedded in the substrate in the embodiment shown in Fig. 9, but any other acoustic mirror structure such as a Bragg reflector is also applicable.

[0096] Figure 26 Fig. 10 is a schematic partial cross-sectional view taken along the O-A line in Fig. 9, according to an exemplary embodiment of the present application. As shown in Fig. 10, the bulk acoustic resonator includes a substrate 200 and an acoustic mirror 210, the acoustic mirror being located on the upper surface of the substrate or embedded in the substrate, the acoustic mirror being composed of a cavity embedded in the substrate in the embodiment shown in Fig. 10, but any other acoustic mirror structure such as a Bragg reflector is also applicable. Figure 25 Fig. 11 is a schematic partial cross-sectional view taken along the O-A line in Fig. 10, according to an exemplary embodiment of the present application. As shown in Fig. 11, the bulk acoustic resonator includes a substrate 200 and an acoustic mirror 210, the acoustic mirror being located on the upper surface of the substrate or embedded in the substrate, the acoustic mirror being composed of a cavity embedded in the substrate in the embodiment shown in Fig. 11, but any other acoustic mirror structure such as a Bragg reflector is also applicable. Figure 26 Fig. 12 is a schematic partial cross-sectional view taken along the O-A line in Fig. 11, according to an exemplary embodiment of the present application. As shown in Fig. 12, the bulk acoustic resonator includes a substrate 200 and an acoustic mirror 210, the acoustic mirror being located on the upper surface of the substrate or embedded in the substrate, the acoustic mirror being composed of a cavity embedded in the substrate in the embodiment shown in Fig. 12, but any other acoustic mirror structure such as a Bragg reflector is also applicable. Figure 26 Fig. 13 is a schematic partial cross-sectional view taken along the O-A line in Fig. 12, according to an exemplary embodiment of the present application. As shown in Fig. 13, the bulk acoustic resonator includes a substrate 200 and an acoustic mirror 210, the acoustic mirror being located on the upper surface of the substrate or embedded in the substrate, the acoustic mirror being composed of a cavity embedded in the substrate in the embodiment shown in Fig. 13, but any other acoustic mirror structure such as a Bragg reflector is also applicable.

[0097] The area where the acoustic mirror 210, the bottom electrode 220, the piezoelectric layer 230, and the top electrode 240 overlap in the thickness direction of the resonator is the effective area of the resonator. The top electrode is located inside the acoustic mirror, and the distance between the top electrode and the acoustic mirror is d14, which is in the range of 0-10 μm. The bottom electrode is located outside the acoustic mirror, and the distance between the first end of the bottom electrode and the acoustic mirror is d13, which is in the range of 0-10 μm. The inserted wing structure 250 has a first end and a second end, the first end of which is located inside the effective area, and the second end of which can be aligned with the edge of the effective area or extend out of the effective area. The distance between the first end of the inserted wing structure 250 and the first end of the top electrode 240 is d22, which is in the range of 0-10 μm, and the height of the inserted wing structure is h1, which is in the range of The inserted protrusion 260 has a first end and a second end. The first end of the inserted protrusion 260 is located inside the effective area, and is closer to the center of the resonator than the first end of the inserted wing structure 250, and the distance between the first end of the inserted protrusion 260 and the first end of the inserted wing structure 250 is d21, which is in the range of 0-10 μm. The second end of the inserted protrusion 260 can be above the inserted wing structure, beyond the outer edge of the top electrode, or can cover the inserted wing structure and continue to extend outward to the ineffective area.

[0098] In the present application, when the inserted protrusion (layer) is a metal material, the wing layer (which can be an inserted wing, an inserted wing, or an inserted wing and an inserted wing) is air or a dielectric material. In the present application, the inserted protrusion can be a dielectric material, and the wing layer is air.

[0099] In addition, in the present application, the inserted protrusion can be above the wing layer, or the wing layer can be above the inserted protrusion.

[0100] Figure 27 is a schematic partial cross-sectional view of the O-B line in Figure 25 is a schematic partial cross-sectional view of the O-B line in Figure 27In the figure, the bottom electrode extends out of the acoustic mirror, and the distance between the edge of the bottom electrode and the acoustic mirror is d25, which ranges from 0-10μm. The inserted bridge structure 250 has a first end and a second end, the first end is located inside the effective area, and the second end is located outside the bottom electrode. The distance between the second end of the inserted bridge structure 250 and the end of the bottom electrode is d26, and the range of d26 is 0-10μm. The inserted protrusion 261 has a first end and a second end. The first end of the inserted protrusion 261 is closer to the center of the resonator than the first end of the inserted bridge portion. The distance between the first end of the inserted protrusion 261 and the first end of the inserted bridge structure is d23, and the range of d23 is 0-10μm; the preferred embodiment of the second end of the inserted protrusion 261 is to extend outward from the second end of the inserted bridge structure, and the distance between the second end of the inserted protrusion 261 and the edge of the bottom electrode is d27, and the range of d27 is 0-20μm.

[0101] Figure 28 According to another exemplary embodiment of the present invention Figure 25 A schematic partial cross-sectional view taken along line OB in FIG. Figure 27 Similar to, except that Figure 28 In the embodiment, the second end of the insertion wing structure 260 does not wrap around the second end of the insertion protrusion structure 250, but is aligned with the second end of the structure 250.

[0102] In the present invention, in a cross-sectional view parallel to the thickness direction of the resonator, the insertion wing structure may cover and surround the insertion protrusion structure or cover a portion of the insertion protrusion structure. Figure 29 A corresponding exemplary embodiment is shown. Figure 29 According to another exemplary embodiment of the present invention Figure 25 The schematic partial cross-sectional view taken along the OB line in FIG. Figure 27 Similar to, except that Figure 29 In the embodiment, the second end of the insertion wing structure 260 does not wrap the second end of the insertion protrusion structure 250 , but is located inside the second end of the insertion protrusion structure 250 .

[0103] Figure 30 is a schematic partial cross-sectional view of a bulk acoustic wave resonator according to an exemplary embodiment of the present invention, the section position of which is similar to Figure 18 OA line in. Figure 30 The embodiment shown is Figure 19 The embodiment shown is similar, except that outside the edge of the effective area, part of the piezoelectric layer 130 above the composite insertion layer (the insertion protrusion 350 corresponding to the first insertion layer and the insertion wing structure corresponding to the second insertion layer) is etched away, and the first end of the top electrode coincides with the first end of the piezoelectric layer in the thickness direction.

[0104] existFigure 30 In the embodiment, the height of the insertion wing structure 360 ​​is h2 and the width is d12. The first end of the insertion protrusion 350 is laterally closer to the center of the resonator than the insertion wing structure 360. The distance between the first end of the insertion protrusion 350 and the first end of the insertion wing structure 360 ​​is d11. The second end of the insertion protrusion 350 can be aligned with the second end of the insertion wing structure 360, or it can continue to extend outward to the inactive area.

[0105] In an exemplary embodiment, the material of the inserted wing structure is a dielectric (eg, SiO2, Si3N4, AlN, doped AlN with a doping concentration different from that of the piezoelectric layer, etc.) or air, and the material of the inserted protrusion is metal.

[0106] In other words: Figure 30 In a cross-sectional view parallel to the thickness direction of the resonator, the second insertion layer (insertion wing structure) covers and surrounds the first insertion layer (insertion protrusion) or covers a portion of the first insertion layer; further, in a cross-sectional view parallel to the thickness direction of the resonator, the outer end of the portion of the piezoelectric layer below the first insertion layer is radially outside the outer end of the portion of the piezoelectric layer above the first insertion layer; further, in a cross-sectional view parallel to the thickness direction of the resonator, the outer end of the top electrode is aligned with the outer end of the portion of the piezoelectric layer above the first insertion layer.

[0107] Figure 31 is a schematic partial cross-sectional view of a bulk acoustic wave resonator according to an exemplary embodiment of the present invention, the section position of which is similar to Figure 18 OA line in. Figure 31 The embodiment shown is Figure 30 The embodiment shown is similar, except that the annular insert protrusion structure is 361 and the annular insert wing structure is 351. The annular insert wing structure 351 has a height of h1 and a lateral distance of d12, and can be made of a dielectric material. The first end of the insert protrusion structure 361 should be closer to the center of the resonator, with a distance d11 from the first end of the annular insert wing structure 351. The second end should at least be connected to the insert wing structure or extend further outward, preferably parallel to the edge of the active area.

[0108] In other words, in Figure 31In the thickness direction of the resonator, at least a portion of the insertion protrusion structure corresponding to the first insertion layer is located above the insertion wing structure corresponding to the second insertion layer; further, in a cross-sectional view parallel to the thickness direction of the resonator, the first insertion layer covers a portion of the second insertion layer or covers the second insertion layer; further, in a cross-sectional view parallel to the thickness direction of the resonator, the outer end of the portion of the piezoelectric layer under the first insertion layer is radially outside the outer end of the portion of the piezoelectric layer above the first insertion layer.

[0109] In the above embodiments, when the second insertion layer is provided as a wing, it is a wing structure; and when the second insertion layer is provided as a bridge, it is a bridge structure. Based on actual conditions, the resonator can only include a wing structure or a bridge structure, or can simultaneously include a bridge structure and a wing structure.

[0110] The following is an example of a simple explanation of the materials of the components of the bulk acoustic wave resonator according to the present application.

[0111] In the present application, the constituent material of the electrode and the insertion protrusion can be gold (Au), tungsten (W), molybdenum (Mo), platinum (Pt), ruthenium (Ru), iridium (Ir), titanium tungsten (TiW), aluminum (Al), titanium (Ti), osmium (Os), magnesium (Mg), gold (Au), tungsten (W), molybdenum (Mo), platinum (Pt), ruthenium (Ru), iridium (Ir), germanium (Ge), copper (Cu), aluminum (Al), chromium (Cr), arsenic-doped gold, and the like.

[0112] In the present application, the passivation layer is a dielectric material, and the wing-bridge structure can also be a dielectric material. The dielectric material can be selected from, but not limited to, one or more of or a combination of silicon dioxide (SiO2), silicon nitride (Si3N4), silicon carbide (SiC), aluminum nitride (AlN), aluminum oxide (Al2O3), porous silicon, fluorinated amorphous carbon, fluoropolymer, parylene, polyarylether, hydrogen silsesquioxane, cross-linked polystyrene polymer, biphenyl cyclobutene, fluorinated silicon dioxide, carbon-doped oxide, and diamond.

[0113] In the present application, the piezoelectric layer material can be aluminum nitride (AlN), doped ALN, zinc oxide (ZnO), lead zirconate titanate (PZT), lithium niobate (LiNbO3), quartz, potassium niobate (KNbO3), or lithium tantalate (LiTaO3), etc., wherein the doped ALN 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), and lutetium (Lu).

[0114] In the present application, the substrate material includes, but is not limited to, monocrystalline silicon (Si), gallium arsenide (GaAs), sapphire, quartz, etc.

[0115] Based on the above embodiments and their drawings, the present application proposes the following technical solutions:

[0116] 1. A bulk acoustic wave resonator, comprising:

[0117] a substrate;

[0118] an acoustic mirror;

[0119] a bottom electrode;

[0120] a top electrode;

[0121] a piezoelectric layer;

[0122] a temperature compensation layer,

[0123] wherein:

[0124] an area where the acoustic mirror, the bottom electrode, the piezoelectric layer, and the top electrode overlap in the thickness direction of the substrate is an effective area of the resonator;

[0125] a composite insertion structure is arranged along the edge of the effective area in the piezoelectric layer, the composite insertion structure includes a first insertion layer and a second insertion layer, at least a portion of the first insertion layer overlaps the effective area in a top view of the resonator, and the first insertion layer at least partially overlaps the second insertion layer in the top view of the resonator, the first insertion layer is a metal material and the second insertion layer is air or a dielectric material, or the first insertion layer is a dielectric material and the second insertion layer is air; and

[0126] at least a portion of the temperature compensation layer is located within the effective area in the top view of the resonator, and the material of the temperature compensation layer is a material opposite to the frequency-temperature coefficient of the piezoelectric layer.

[0127] 2. The resonator according to 1, wherein:

[0128] In a plan view of the resonator, the temperature compensation layer does not overlap the composite insertion structure in the lateral direction.

[0129] 3. The resonator according to 2, wherein:

[0130] In a plan view of the resonator, the temperature compensation layer is located between the composite insertion structures in the lateral direction.

[0131] 4. The resonator according to 1, wherein:

[0132] In a plan view of the resonator, the temperature compensation layer has an overlapping portion with the composite insertion structure in the lateral direction.

[0133] 5. The resonator according to 4, wherein:

[0134] In a plan view of the resonator, the temperature compensation layer is located between corresponding first insertion layers or between corresponding second insertion layers of the composite insertion structure in the lateral direction.

[0135] 6. The resonator according to 4, wherein:

[0136] In a plan view of the resonator, both ends of the temperature compensation layer overlap the first insertion layer and the second insertion layer of the composite insertion structure in the lateral direction.

[0137] 7. The resonator according to 4, wherein:

[0138] In a plan view of the resonator, at least one end of the temperature compensation layer is located outside the composite insertion structure in the lateral direction.

[0139] 8. The resonator according to any one of 1 to 7, wherein:

[0140] The temperature compensation layer is located in the bottom electrode, or in the piezoelectric layer, or in the top electrode, or on the bottom electrode side, or on the top electrode side, or between the bottom electrode and the piezoelectric layer, or between the top electrode and the piezoelectric layer.

[0141] 9. The resonator according to any one of 1 to 7, wherein:

[0142] The temperature compensation layer is located in the bottom electrode or in the top electrode; and

[0143] The resonator further includes a cut-off layer provided below the temperature compensation layer.

[0144] 10. The resonator according to any one of 1 to 7, wherein:

[0145] The temperature compensating layer is located in the bottom electrode, the resonator further comprises a cutoff layer disposed below the temperature compensating layer, and a passivation layer disposed above the temperature compensating layer to cover the temperature compensating layer, in a cross section parallel to the thickness direction of the resonator, the passivation layer and the cutoff layer enclose the temperature compensating layer; or

[0146] The temperature compensating layer is located in the piezoelectric layer, the resonator further comprises a cutoff layer disposed below the temperature compensating layer, a passivation layer disposed above the temperature compensating layer to cover the temperature compensating layer, and a covering metal layer, in a cross section parallel to the thickness direction of the resonator, the passivation layer and the cutoff layer enclose the temperature compensating layer, and the covering metal layer covers the passivation layer and the cutoff layer.

[0147] 11. The resonator according to any one of 1-7, wherein:

[0148] The piezoelectric layer comprises a first piezoelectric layer and a second piezoelectric layer located below the first piezoelectric layer, and the composite insertion structure is located between the first piezoelectric layer and the second piezoelectric layer; and

[0149] The temperature compensating layer is located in the second piezoelectric layer, or between the first piezoelectric layer and the second piezoelectric layer, or in the first piezoelectric layer.

[0150] 12. The resonator according to any one of 1-11, wherein:

[0151] In the thickness direction of the resonator, at least a portion of the second insertion layer is located above the first insertion layer.

[0152] 13. The resonator according to 12, wherein:

[0153] In a cross section parallel to the thickness direction of the resonator, the second insertion layer covers and encloses the first insertion layer or covers a portion of the first insertion layer.

[0154] 14. The resonator according to 13, wherein:

[0155] In a cross section parallel to the thickness direction of the resonator, the outer end of the portion of the piezoelectric layer below the first insertion layer is radially outside the outer end of the portion of the piezoelectric layer above the first insertion layer.

[0156] 15. The resonator according to 14, wherein:

[0157] In a cross section parallel to the thickness direction of the resonator, the outer end of the top electrode is aligned with the outer end of the portion of the piezoelectric layer above the first insertion layer.

[0158] 16. The resonator according to any one of 1-11, wherein:

[0159] At least a portion of the first interposition layer is located above the second interposition layer in the thickness direction of the resonator.

[0160] 17. The resonator according to 16, wherein:

[0161] In a cross-sectional view parallel to the thickness direction of the resonator, the first interposition layer covers a portion of the second interposition layer or covers the second interposition layer.

[0162] 18. The resonator according to 17, wherein:

[0163] In a cross-sectional view parallel to the thickness direction of the resonator, the outer end of the portion of the piezoelectric layer under the first interposition layer is radially outside the outer end of the portion of the piezoelectric layer over the first interposition layer.

[0164] 19. The resonator according to 18, wherein:

[0165] In a cross-sectional view parallel to the thickness direction of the resonator, the outer end of the top electrode is aligned with the outer end of the portion of the piezoelectric layer over the first interposition layer and the outer end of the first interposition layer.

[0166] 20. The resonator according to any one of 1 to 11, wherein:

[0167] In a plan view of the resonator, the second interposition layer, the first interposition layer and the effective area at least partially overlap.

[0168] 21. The resonator according to any one of 1 to 11, wherein:

[0169] The composite interposition structure is a ring-shaped interposition structure.

[0170] 22. The resonator according to 21, wherein:

[0171] In a plan view of the resonator, the second interposition layer includes an interposition wing structure provided on the side of the electrode non-connecting edge.

[0172] 23. The resonator according to 21, wherein:

[0173] In a plan view of the resonator, the second interposition layer includes an interposition bridge structure provided on the side of the electrode connecting edge.

[0174] 24. The resonator according to 23, wherein:

[0175] The distance between the outer end of the interposition bridge structure and the end portion of the bottom electrode in the radial direction is in the range of 0 to 20 μm.

[0176] 25. The resonator according to 24, wherein:

[0177] the first insertion layer extends beyond the bottom electrode, the outer end of the first insertion layer is located within 0-10 μm in the radial direction from the end of the bottom electrode, and the outer end of the insertion bridge structure is located more than the outer end of the first insertion layer in the radial direction from the end of the bottom electrode.

[0178] 26. The resonator according to any one of 1-11, wherein:

[0179] at least a part of the first insertion layer in a portion overlapping with the effective area in a plan view of the resonator is a flat insertion portion.

[0180] 27. The resonator according to 26, wherein:

[0181] the first insertion layer is a flat layer protrusion.

[0182] 28. The resonator according to 26, wherein:

[0183] the first insertion layer includes the flat insertion portion and a protrusion step portion forming a step with the flat insertion portion; and / or

[0184] the second insertion layer includes a wing bridge step portion.

[0185] 29. The resonator according to any one of 1-11, wherein:

[0186] at least a part of the composite insertion structure is located at an intermediate position of a corresponding portion of the piezoelectric layer in the thickness direction of the piezoelectric layer.

[0187] 30. The resonator according to any one of 1-29, wherein:

[0188] a distance in the radial direction between the inner end of the first insertion layer and the inner end of the second insertion layer is within 0-10 μm.

[0189] 31. The resonator according to 30, wherein:

[0190] a range of overlap in the thickness direction of the resonator among the first insertion layer, the second insertion layer, and the effective area is within 0-10 μm.

[0191] 32. The resonator according to any one of 1-30, wherein:

[0192] a thickness of the first insertion layer is within a range of and / or a thickness of the second insertion layer is within a range of ​

[0193] 33. The resonator according to any one of 1-32, wherein:

[0194] the metal material is at least one of gold (Au), tungsten (W), molybdenum (Mo), platinum (Pt), ruthenium (Ru), iridium (Ir), titanium tungsten (TiW), aluminum (Al), titanium (Ti), osmium (Os), magnesium (Mg), gold (Au), tungsten (W), molybdenum (Mo), platinum (Pt), ruthenium (Ru), iridium (Ir), germanium (Ge), copper (Cu), aluminum (Al), chromium (Cr), arsenic-doped gold; and combinations thereof.

[0195] the dielectric material is at least one of silicon dioxide (SiO2), silicon nitride (Si3N4), silicon carbide (SiC), aluminum nitride (AIN), aluminum oxide (AI2O3), porous silicon, fluorinated amorphous carbon, fluoropolymers, parylene, polyarylether, hydrogensilsesquioxane, cross-linked polyphenyl polymer, biphenyl cyclobutene, fluorinated silicon dioxide, carbon-doped oxide, and diamond.

[0196] 34. The resonator according to 1, wherein:

[0197] the first insertion layer and / or the second insertion layer cross the boundary of the active area.

[0198] 35. The resonator according to 1, wherein:

[0199] the composite insertion structure is disposed between a first piezoelectric layer portion and a second piezoelectric layer portion, the first piezoelectric layer portion and the second piezoelectric layer portion constituting the piezoelectric layer, the material constituting the first piezoelectric layer portion being different from the material constituting the second piezoelectric layer portion.

[0200] 36. The resonator according to 1, wherein:

[0201] the material forming the temperature compensation layer comprises silicon dioxide or doped silicon dioxide.

[0202] 37. A filter comprising the resonator described above.

[0203] 38. An electronic device comprising the resonator described above, or the filter described above. It is noted that the electronic device herein includes, but is not limited to, intermediate products such as radio frequency front-ends, filter-amplification modules, and terminal products such as mobile phones, WIFI, and drones.

[0204] Although embodiments of the present application have been shown and described, it is to be understood that various modifications can be made to these embodiments without departing from the principles and spirit of the application, the scope of which is to be determined only by the appended claims and their equivalents.

Claims

1. A bulk acoustic wave resonator, comprising: substrate; Acoustic mirror; bottom electrode; Top electrode; Piezoelectric layer; Warming layer, in: The area where the acoustic mirror, bottom electrode, piezoelectric layer, and top electrode overlap in the thickness direction of the substrate is the effective area of ​​the resonator; The piezoelectric layer is provided with a composite insertion structure arranged along an edge of the active area, the composite insertion structure comprising a first insertion layer and a second insertion layer, at least a portion of the first insertion layer overlaps with the active area in a top view of the resonator, and the first insertion layer and the second insertion layer at least partially overlap in a top view of the resonator, the first insertion layer is a metal material and the second insertion layer is air or a dielectric material, or the first insertion layer is a dielectric material and the second insertion layer is air; a horizontal center line of the composite insertion structure is located between three equal bisectors of the piezoelectric layer in a thickness direction; In a top view of the resonator, at least a portion of the temperature compensating layer is located within the effective region, and a material of the temperature compensating layer is a material having a frequency temperature coefficient opposite to that of the piezoelectric layer; and The composite insertion structure is formed with an insertion step surface outside the effective area, and the upper surface of the portion of the piezoelectric layer above the composite insertion structure is formed with a piezoelectric layer step surface based on the insertion step surface; or the composite insertion structure is formed with an insertion step surface at the non-connected side of the top electrode, and the upper surface of the portion of the piezoelectric layer above the composite insertion structure is formed with a piezoelectric layer step surface based on the insertion step surface; The temperature compensation layer is located in the piezoelectric layer, and the resonator further includes a cutoff layer arranged below the temperature compensation layer, a passivation layer arranged above the temperature compensation layer and covering the temperature compensation layer, and a coating metal layer. In a cross section parallel to the thickness direction of the resonator, the passivation layer and the cutoff layer surround the temperature compensation layer, and the coating metal layer covers the passivation layer and the cutoff layer.

2. The resonator according to claim 1, wherein: In a top view of the resonator, the temperature compensation layer does not overlap with the composite insertion structure in a lateral direction.

3. The resonator according to claim 2, wherein: In a top view of the resonator, the temperature compensation layer is located between the composite insertion structures in a lateral direction.

4. The resonator according to claim 1, wherein: In a top view of the resonator, the temperature compensation layer overlaps with the composite insertion structure in a lateral direction.

5. The resonator according to claim 4, wherein: In a top view of the resonator, the temperature compensation layer is located between corresponding first insertion layers or between corresponding second insertion layers of the composite insertion structure in a lateral direction.

6. The resonator of claim 4, wherein: In a top view of the resonator, both ends of the temperature compensation layer in a lateral direction overlap with the first insertion layer and the second insertion layer of the composite insertion structure.

7. The resonator according to claim 4, wherein: In a top view of the resonator, at least one end portion of the temperature compensation layer is located outside the composite insert structure in a lateral direction.

8. The resonator of claim 1 , wherein: The temperature compensation layer is located in the bottom electrode, or in the piezoelectric layer, or in the top electrode, or on the lower side of the bottom electrode, or on the upper side of the top electrode, or between the bottom electrode and the piezoelectric layer, or between the top electrode and the piezoelectric layer.

9. The resonator of claim 1 , wherein: The piezoelectric layer includes a first piezoelectric layer and a second piezoelectric layer located below the first piezoelectric layer, and the composite insertion structure is located between the first piezoelectric layer and the second piezoelectric layer; and The temperature compensation layer is located in the second piezoelectric layer, or between the first piezoelectric layer and the second piezoelectric layer, or in the first piezoelectric layer.

10. The resonator of claim 1 , wherein: At least a portion of the second insertion layer is located above the first insertion layer in a thickness direction of the resonator.

11. The resonator of claim 10, wherein: In a cross-sectional view parallel to the thickness direction of the resonator, the second insertion layer covers and surrounds the first insertion layer or covers a portion of the first insertion layer.

12. The resonator of claim 11, wherein: In a cross-sectional view parallel to the thickness direction of the resonator, the outer end of the portion of the piezoelectric layer below the first insertion layer is radially outside the outer end of the portion of the piezoelectric layer above the first insertion layer.

13. The resonator of claim 12, wherein: In a cross-sectional view parallel to the thickness direction of the resonator, an outer end of the top electrode is aligned with an outer end of a portion of the piezoelectric layer above the first insertion layer.

14. The resonator of claim 1 , wherein: At least a portion of the first insertion layer is located above the second insertion layer in a thickness direction of the resonator.

15. The resonator of claim 14, wherein: In a cross-sectional view parallel to the thickness direction of the resonator, the first insertion layer covers and surrounds the second insertion layer or covers a portion of the second insertion layer.

16. The resonator of claim 15, wherein: In a cross-sectional view parallel to the thickness direction of the resonator, the outer end of the portion of the piezoelectric layer below the first insertion layer is radially outside the outer end of the portion of the piezoelectric layer above the first insertion layer.

17. The resonator of claim 16, wherein: In a cross-sectional view parallel to the thickness direction of the resonator, an outer end of the top electrode is aligned with an outer end of a portion of the piezoelectric layer above the first insertion layer and an outer end of the first insertion layer.

18. The resonator of claim 15, wherein: In a top view of the resonator, the second insertion layer, the first insertion layer, and the active area at least partially overlap.

19. The resonator of claim 15, wherein: The composite insert structure is an annular insert structure.

20. The resonator of claim 19, wherein: In a top view of the resonator, the second insertion layer includes an insertion wing structure provided on a non-connected side of the electrode.

21. The resonator of claim 19, wherein: In a top view of the resonator, the second insertion layer includes an insertion bridge structure provided on an electrode connection side.

22. The resonator of claim 21 , wherein: The distance between the outer end of the insertion bridge structure and the end of the bottom electrode in the radial direction is within the range of 0-20 μm.

23. The resonator of claim 22, wherein: The first insertion layer extends beyond the bottom electrode, and the distance between the outer end of the first insertion layer and the end of the bottom electrode in the radial direction is in the range of 0-10 μm, and the distance between the outer end of the insertion bridge structure and the end of the bottom electrode in the radial direction is greater than the distance between the outer end of the first insertion layer and the end of the bottom electrode in the radial direction.

24. The resonator of claim 15, wherein: At least a portion of the first insertion layer that overlaps with the active area in a plan view of the resonator is a flat insertion portion.

25. The resonator of claim 24, wherein: The first insertion layer is a flat convex layer.

26. The resonator of claim 24, wherein: The first insertion layer includes the flat insertion portion and a raised step portion forming a step with the flat insertion portion; and / or The second insert layer includes a wing bridge step portion.

27. The resonator of claim 1, wherein: At least a portion of the composite interposer structure is disposed at a middle position of a corresponding portion of the piezoelectric layer in a thickness direction of the piezoelectric layer.

28. The resonator according to any one of claims 1 to 27, wherein: A radial distance between an inner end of the first insertion layer and an inner end of the second insertion layer is in a range of 0-10 μm.

29. The resonator of claim 28, wherein: The overlapping range of the first insertion layer, the second insertion layer and the effective area in the thickness direction of the resonator is 0-10 μm.

30. The resonator of any one of claims 1 to 27, wherein: The thickness of the first insertion layer is and / or the thickness of the second insertion layer is within the range of within the range.

31. The resonator of any one of claims 1 to 27, wherein: The metal material is at least one of the following materials and a combination thereof: gold (Au), tungsten (W), molybdenum (Mo), platinum (Pt), ruthenium (Ru), iridium (Ir), titanium tungsten (TiW), aluminum (Al), titanium (Ti), osmium (Os), magnesium (Mg), gold (Au), tungsten (W), molybdenum (Mo), platinum (Pt), ruthenium (Ru), iridium (Ir), germanium (Ge), copper (Cu), aluminum (Al), chromium (Cr), arsenic-doped gold; and The dielectric material is at least one of the following materials and combinations thereof: silicon dioxide (SiO2), silicon nitride (Si3N4), silicon carbide (SiC), aluminum nitride (AlN), aluminum oxide (Al2O3), porous silicon, fluorinated amorphous carbon, fluoropolymer, polyparaxylene, polyarylene ether, hydrogen silsesquioxane, cross-linked polyphenylene polymer, bisphenylcyclobutene, fluorinated silicon dioxide, carbon-doped oxide and diamond.

32. The resonator of claim 1 , wherein: The first insertion layer and / or the second insertion layer straddles a boundary of the active area.

33. The resonator of claim 1 , wherein: The composite insert structure is disposed between a first piezoelectric layer portion and a second piezoelectric layer portion. The first piezoelectric layer portion and the second piezoelectric layer portion constitute the piezoelectric layer. A material constituting the first piezoelectric layer portion is different from a material constituting the second piezoelectric layer portion.

34. The resonator of claim 1 , wherein: The material forming the temperature compensation layer includes silicon dioxide or doped silicon dioxide.

35. A filter comprising: A bulk acoustic wave resonator according to any one of claims 1 to 34.

36. An electronic device comprising the bulk acoustic wave resonator according to any one of claims 1 to 34, or the filter according to claim 35.

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