Bulk acoustic wave resonator with temperature compensation layer, filter, and electronic device

Abstract

The present application relates to a bulk acoustic wave resonator, comprising: a substrate; an acoustic mirror; a bottom electrode; a top electrode; and a piezoelectric layer disposed between the bottom electrode and the top electrode, wherein: the resonator further comprises a temperature compensation layer disposed in the piezoelectric layer or in the bottom electrode or between the piezoelectric layer and the bottom electrode, and an edge portion of the temperature compensation layer has a bevel, the bevel has an upper end edge and a lower end edge, the lower end edge is outside the upper end edge in a horizontal direction; and the top electrode is provided with a wing bridge portion along an effective area of the resonator, a gap is defined between the wing bridge portion and the piezoelectric layer, and an inner edge of the gap is between the upper end edge and the lower end edge in the horizontal direction. The present application also relates to a filter and an electronic device.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the field of semiconductor, and in particular to a bulk acoustic wave resonator, a filter having the resonator, and an electronic device. BACKGROUND

[0002] With the development of 5G communication technology, the requirements for communication frequency bands are becoming higher and higher. The traditional radio frequency filter cannot meet the requirements of high frequency communication due to the limitations of structure and performance. As a new type of MEMS device, the film bulk acoustic resonator (FBAR) has the advantages of small size, light weight, low insertion loss, wide frequency band, and high quality factor, which well adapts to the upgrading of wireless communication systems, making the FBAR technology one of the research hotspots in the field of communication.

[0003] The main structure of the film bulk acoustic resonator is a "sandwich" structure composed of an electrode-piezoelectric film-electrode, that is, a layer of piezoelectric material is sandwiched between two metal electrode layers. By inputting a sinusoidal signal between the two electrodes, the FBAR converts the input electrical signal into mechanical resonance through the inverse piezoelectric effect, and then converts the mechanical resonance into an electrical signal output through the piezoelectric effect. The film bulk acoustic resonator mainly utilizes the longitudinal piezoelectric coefficient of the piezoelectric film to generate the piezoelectric effect, so its main working mode is the longitudinal wave mode in the thickness direction, that is, the acoustic wave of the bulk acoustic resonator is mainly in the film bulk, and the main vibration direction is in the longitudinal direction. However, due to the existence of the boundary, there will be Lamb waves not perpendicular to the piezoelectric film layer at the boundary, at which time the transverse Lamb waves will leak out of the transverse direction of the piezoelectric film layer, resulting in acoustic loss and thus reducing the Q value of the resonator.

[0004] In addition, the bulk acoustic resonator generally has a negative frequency temperature drift coefficient, and its frequency temperature drift coefficient is about -30 PPM / K, which is due to the fact that the piezoelectric material and the electrode material of the bulk acoustic resonator have a negative frequency temperature drift coefficient, which means that the stiffness of these materials will decrease as the temperature rises. The reduction in stiffness will cause the speed of sound to decrease. Based on the formula V = F * λ = F * 2d (where V is the speed of sound, F is the frequency, λ is the wavelength, and d is the thickness of the piezoelectric layer), as the speed of sound decreases, the frequency will decrease, and therefore, the bulk acoustic resonator has the phenomenon of frequency drift as the temperature rises.

[0005] In order to reduce the temperature drift effect of the resonator, a layer of material with a positive frequency temperature drift coefficient (temperature compensation layer) can usually be added to the resonator. However, after introducing the above-mentioned temperature compensation layer into the resonator, the performance of the resonator will be deteriorated, mainly reflected in the increase of the resonator loss leading to the reduction of the Q value, and the decrease of the electromechanical coupling coefficient (Kt 2 ). The loss of the resonator directly affects the passband insertion loss characteristics of the filter, thereby increasing the loss in the radio frequency link and deteriorating the transceiver performance of the radio frequency front end. SUMMARY

[0006] To alleviate or solve at least one aspect of the above problems in the prior art, the present application is proposed.

[0007] According to an aspect of an embodiment of the present application, a bulk acoustic wave resonator is proposed, comprising:

[0008] a substrate;

[0009] an acoustic mirror;

[0010] a bottom electrode;

[0011] a top electrode; and

[0012] a piezoelectric layer disposed between the bottom electrode and the top electrode,

[0013] wherein:

[0014] the resonator further comprises a temperature compensation layer disposed in the piezoelectric layer or in the bottom electrode or between the piezoelectric layer and the bottom electrode, and an edge portion of the temperature compensation layer has a bevel having an upper end edge and a lower end edge, the lower end edge being laterally outward of the upper end edge; and

[0015] the top electrode is provided with a wing bridge portion along an active area of the resonator, a gap being defined between the wing bridge portion and the piezoelectric layer, an inner edge of the gap being laterally between the upper end edge and the lower end edge.

[0016] An embodiment of the present application further relates to a bulk acoustic wave resonator, comprising:

[0017] a substrate;

[0018] an acoustic mirror;

[0019] a bottom electrode;

[0020] a top electrode; and

[0021] a piezoelectric layer disposed between the bottom electrode and the top electrode,

[0022] wherein:

[0023] the resonator further comprises a temperature compensation layer disposed in the piezoelectric layer or in the bottom electrode or between the piezoelectric layer and the bottom electrode;

[0024] the temperature compensation layer is laterally inward of a boundary of the acoustic mirror; and

[0025] the top electrode is provided with a wing bridge portion along an active area of the resonator, a gap being defined between the wing bridge portion and the piezoelectric layer, an inner edge of the gap being laterally between the boundary of the acoustic mirror and an edge of the temperature compensation layer.

[0026] Embodiments of the present application also relate to a filter including the bulk acoustic wave resonator described above.

[0027] Embodiments of the present application also relate to an electronic device including the filter described above or the resonator described above. BRIEF DESCRIPTION OF DRAWINGS

[0028] The following description with reference to the drawings can better help understand these and other features and advantages of the various embodiments disclosed by the present application, in which the same reference numerals are always used to designate the same components, in which:

[0029] Figure 1 A cross-sectional view showing the relative position between the temperature compensating layer and the bridge gap in the prior art;

[0030] Figure 2 Q values of resonators obtained based on the structure in Figure 1 ;

[0031] Figure 3 A cross-sectional view of a bulk acoustic wave resonator according to an exemplary embodiment of the present application, in which the projection of the inner edge of the bridge gap in the vertical direction is on the left side slope of the temperature compensating layer;

[0032] Figure 4 Q values of resonators obtained based on the structure in Figure 3 ;

[0033] Figure 5 A cross-sectional view of a bulk acoustic wave resonator according to another exemplary embodiment of the present application, in which the projection of the inner edge of the suspension wing gap in the vertical direction is on the left side slope of the temperature compensating layer;

[0034] Figure 6 A cross-sectional view of a bulk acoustic wave resonator according to still another exemplary embodiment of the present application, in which the projection of the inner edge of the suspension wing gap in the vertical direction is on the left side slope of the temperature compensating layer, and the projection of the inner edge of the bridge gap in the vertical direction is on the right side slope of the temperature compensating layer. DETAILED DESCRIPTION

[0035] The technical solutions of the present application will be further described below by way of examples in conjunction with the drawings. In the description, identical or similar reference numerals indicate identical or similar components. The following description of the embodiments of the present application with reference to the drawings is intended to explain the general inventive concept of the present application, and should not be understood as a limitation of the present application. The following description is only one of the embodiments of the present application, and is not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art belong to the scope of protection of the present application.

[0036] First, the reference signs in the drawings of the present application are explained as follows:

[0037] 1: substrate, optional materials are single crystal silicon, gallium nitride, gallium arsenide, sapphire, quartz, silicon carbide, diamond, etc.

[0038] 2: acoustic mirror, which can be a cavity, or can adopt Bragg reflection layer and other equivalent forms. The embodiment shown in the present application is a cavity arranged on the upper surface of the substrate. In optional embodiments, the cavity can also be located inside the substrate.

[0039] 3: first seed layer, optional materials are aluminum nitride, zinc oxide, PZT, etc. and rare earth element doped materials containing a certain atomic ratio of the above materials.

[0040] 4: first bottom electrode layer, materials can be selected from: 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 similar metals.

[0041] 5: temperature compensation layer, the material of the temperature compensation layer is a material opposite to the frequency temperature coefficient of the piezoelectric layer. The material can be selected from: silicon dioxide (SiO2), doped silicon dioxide (such as F-doped), polysilicon, borophosphosilicate glass (BSG), chromium (Cr), or tellurium oxide (TeO(x)), and other positive temperature coefficient materials. For example, the stiffness of SiO2 and positive frequency temperature drift coefficient material will increase with the increase of temperature, so that the decrease of resonator stiffness and the decrease of acoustic velocity caused by the decrease of resonator stiffness can be prevented or reduced, thereby preventing or reducing frequency drift.

[0042] 6: second bottom electrode layer, materials can be selected from: 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 similar metals. The first bottom electrode layer and the second bottom electrode layer form a sandwich electrode, and together serve as a bottom electrode.

[0043] 7: piezoelectric layer, which can be a single crystal piezoelectric material, optionally, such as single crystal aluminum nitride, single crystal gallium nitride, single crystal lithium niobate, single crystal lead zirconate titanate (PZT), single crystal potassium niobate, single crystal quartz thin film, or single crystal lithium tantalate, etc., or a polycrystalline piezoelectric material (as opposed to single crystal, non-single crystal material), optionally, such as polycrystalline aluminum nitride, zinc oxide, PZT, etc., or a rare earth element doped material containing a certain atomic ratio of the above materials, for example, doped aluminum nitride, doped aluminum nitride containing at least one rare earth element, such as scandium (Sc), yttrium (Y), magnesium (Mg), titanium (Ti), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), etc.

[0044] 8: top electrode, which can have the same material as the bottom electrode, and the material can be selected from molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium, or a composite or alloy thereof.

[0045] 9: passivation layer or process layer, which is provided on the top electrode of the resonator, and the process layer can be a mass adjustment load or a passivation layer, and the material can be a dielectric material, such as silicon dioxide, aluminum nitride, silicon nitride, etc.

[0046] 10: second seed layer, which can be selected from aluminum nitride, zinc oxide, PZT, etc., and a rare earth element doped material containing a certain atomic ratio of the above materials.

[0047] 11: third seed layer, which can be selected from aluminum nitride, zinc oxide, PZT, etc., and a rare earth element doped material containing a certain atomic ratio of the above materials.

[0048] 12: bridge gap, which can be an air gap or filled with a dielectric material.

[0049] 13: wing gap, which can be an air gap or filled with a dielectric material.

[0050] Figure 1 A cross-sectional view showing the relative positions of the temperature compensation layer and the bridge gap in the prior art is shown.

[0051] As shown in Figure 1 , the resonator includes the above-mentioned substrate 1, acoustic mirror 2, first to third seed layers 3, 10 and 11, first bottom electrode layer 4, temperature compensation layer 5, second bottom electrode layer 6, piezoelectric layer 7, top electrode 8, and passivation layer 9. The electrode connection end of the top electrode is provided with a bridge, which defines a bridge gap 12.

[0052] In Figure 1In the embodiment shown in FIG. 1, the temperature compensating layer 5 has a trapezoidal cross section with two oblique sides. As shown in FIG. 2, the outer end of the temperature compensating layer 5 has an oblique side with an upper end edge 5A and a lower end edge 5B, the lower end edge 5B being outside the upper end edge 5A. Figure 1 As shown in FIG. 2, the inner edge of the bridge gap 12 is inside the upper end edge 5A in the horizontal direction, i.e., in the vertical projection, the inner edge of the bridge gap 12 falls within the range of the top side of the trapezoidal cross section of the temperature compensating layer.

[0053] As shown in FIG. 2, the inner edge of the bridge gap 12 is inside the upper end edge 5A in the horizontal direction, i.e., in the vertical projection, the inner edge of the bridge gap 12 falls within the range of the top side of the trapezoidal cross section of the temperature compensating layer. Figure 1

[0054] As shown in FIG. 2, the inner edge of the bridge gap 12 is inside the upper end edge 5A in the horizontal direction, i.e., in the vertical projection, the inner edge of the bridge gap 12 falls within the range of the top side of the trapezoidal cross section of the temperature compensating layer. Figure 2 Figure 1 As shown in FIG. 2, the inner edge of the bridge gap 12 is inside the upper end edge 5A in the horizontal direction, i.e., in the vertical projection, the inner edge of the bridge gap 12 falls within the range of the top side of the trapezoidal cross section of the temperature compensating layer.

[0055] Figure 3 As shown in FIG. 2, the inner edge of the bridge gap 12 is inside the upper end edge 5A in the horizontal direction, i.e., in the vertical projection, the inner edge of the bridge gap 12 falls within the range of the top side of the trapezoidal cross section of the temperature compensating layer.

[0056] As shown in FIG. 2, the inner edge of the bridge gap 12 is inside the upper end edge 5A in the horizontal direction, i.e., in the vertical projection, the inner edge of the bridge gap 12 falls within the range of the top side of the trapezoidal cross section of the temperature compensating layer. Figure 3 As shown in FIG. 2, the inner edge of the bridge gap 12 is inside the upper end edge 5A in the horizontal direction, i.e., in the vertical projection, the inner edge of the bridge gap 12 falls within the range of the top side of the trapezoidal cross section of the temperature compensating layer.

[0057] Figure 3 As shown in FIG. 2, the inner edge of the bridge gap 12 is inside the upper end edge 5A in the horizontal direction, i.e., in the vertical projection, the inner edge of the bridge gap 12 falls within the range of the top side of the trapezoidal cross section of the temperature compensating layer.

[0058] As shown in FIG. 2, the inner edge of the bridge gap 12 is inside the upper end edge 5A in the horizontal direction, i.e., in the vertical projection, the inner edge of the bridge gap 12 falls within the range of the top side of the trapezoidal cross section of the temperature compensating layer. Figure 3 As shown in FIG. 2, the inner edge of the bridge gap 12 is inside the upper end edge 5A in the horizontal direction, i.e., in the vertical projection, the inner edge of the bridge gap 12 falls within the range of the top side of the trapezoidal cross section of the temperature compensating layer.

[0059] Figure 3 As shown in FIG. 2, the inner edge of the bridge gap 12 is inside the upper end edge 5A in the horizontal direction, i.e., in the vertical projection, the inner edge of the bridge gap 12 falls within the range of the top side of the trapezoidal cross section of the temperature compensating layer. Figure 3 As shown in FIG. 2, the inner edge of the bridge gap 12 is inside the upper end edge 5A in the horizontal direction, i.e., in the vertical projection, the inner edge of the bridge gap 12 falls within the range of the top side of the trapezoidal cross section of the temperature compensating layer.

[0060] Figure 3 ​​​​As shown, the inner edge of the bridge gap 12 is projected on the side slope of the temperature compensation layer in the vertical direction, i.e. between the upper end edge 5A and the lower end edge 5B of the side slope. Figure 3 As shown in the structure, the inner edge of the bridge gap 12 is in the horizontal direction between the upper end edge 5A and the lower end edge 5B of the side slope.

[0061] Figure 3 The structure shown in Figure 1 The difference between the structure shown in Figure 3 In the structure, the inner edge of the bridge gap 12 is at a position on the side slope where the distance to the upper end edge 5A is about one fourth of the length of the side slope; while in Figure 1 In the structure, as described above, the inner edge of the bridge gap 12 is on the inner side of the upper end edge 5A in the horizontal direction.

[0062] Figure 4 The Q value of the resonator obtained based on the structure in Figure 3 It can be seen that in the frequency range of 0.8GHz-1.3GHz, the Q value of the resonator is about 6133 at the highest point m21, and the corresponding frequency is about 1.1GHz.

[0063] Comparing Figure 4 with Figure 2 It can be seen that, under the same conditions, by selecting the position of the inner edge of the bridge gap 12 relative to the side slope of the temperature compensation layer 5, Figure 3 the Q value of the resonator obtained by the structure shown in Figure 1 is greater than the Q value of the resonator obtained by the structure shown in

[0064] The transverse acoustic wave is generated inside the effective area of the resonator (the effective area is the overlapping area of the top electrode, the piezoelectric layer, the bottom electrode and the acoustic mirror of the resonator in the thickness direction of the resonator, which is A1 in Figure 1 and A2 in Figure 3 ). Generally, when the transverse acoustic wave encounters a point of acoustic impedance mismatch, it will be reflected. This reflection will cause part of the transverse wave to be reflected back to the effective area, increasing the total acoustic energy in the effective area of the resonator, thereby reducing the loss of total acoustic energy in the effective area of the resonator and improving the Q value. For the structure in Figure 3 , the inner edge of the bridge gap 12 is between the upper end edge and the lower end edge of the temperature compensation layer, and there are two points of acoustic impedance mismatch in the effective area, corresponding to the upper end edge of the temperature compensation layer and the inner edge of the bridge gap 12. Therefore, for the resonator of the structure in Figure 3 , the transverse acoustic wave will be reflected twice at the two points of acoustic impedance mismatch, so more transverse wave energy is confined in the effective area of the resonator, and the Q value is improved.Figure 1 In the structure described, the effective region has only one acoustic impedance mismatch point, corresponding to the inner edge of the bridge gap 12. Therefore, for Figure 1 The resonator structure ensures that transverse sound waves undergo only one reflection. Compared to... Figure 3 Structural resonators Figure 1 The resonator structure restricts less transverse wave energy within the effective region, resulting in a lower Q value.

[0065] It should be noted that as long as the inner edge of the bridge gap 12 is located between the upper edge 5A and the lower edge 5B in the horizontal direction, it is within the protection scope of this invention. Figure 3 The specific location of the inner edge of the bridge gap 12 shown is merely exemplary. In a more specific embodiment, there is a slope length (i.e., the length of the side slope) between the upper edge 5A and the lower edge 5B, on which the inner edge of the bridge gap 12 is located within the following range: the distance from the inner side of the range to the upper edge 5A is within one-third to one-quarter of the slope length, and the distance from the outer side of the range to the lower edge 5B is within one-third to one-quarter of the slope length.

[0066] In an optional embodiment, the acute angle formed between the side slope of the temperature compensation layer and the bottom surface of the temperature compensation layer is less than 15 degrees.

[0067] Figure 3 In the illustrated embodiment, a bridge portion is provided at the electrode connection end of the top electrode, which defines a bridge gap. However, the invention is not limited to this. A similar gap can also be provided at the non-electrode connection end of the top electrode, and the positional relationship between the inner edge of the gap and the corresponding inclined surface of the temperature compensation layer is defined.

[0068] Figure 5 This is a cross-sectional schematic diagram of a bulk acoustic resonator according to another exemplary embodiment of the present invention.

[0069] like Figure 5 As shown, the resonator includes the aforementioned substrate 1, acoustic mirror 2, first to third seed layers 3, 10 and 11, first bottom electrode layer 4, temperature compensation layer 5, second bottom electrode layer 6, piezoelectric layer 7, top electrode 8, and passivation layer 9. A wing is provided at the non-electrode connection end of the top electrode 8, which defines a wing gap 13.

[0070] like Figure 5 As shown, the projection of the inner edge of the cantilever gap 13 in the vertical direction lies on the inclined surface of the left side of the temperature compensation layer. Figure 5 In the middle, the temperature compensation layer 5 is roughly a trapezoidal cross-section with two sloping sides. For example... Figure 5 As shown, the outer end of the thermal compensation layer 5 has an inclined side surface, which has an upper edge 5A and a lower edge 5B, with the lower edge 5B located outside the upper edge 5A.

[0071] like Figure 5 As shown, the projection of the inner edge of the cantilever gap 13 in the vertical direction lies on the lateral inclined surface of the temperature compensation layer, that is, in Figure 5 In the structure shown, the inner edge of the cantilever gap 13 is located in the horizontal direction between the upper edge 5A and the lower edge 5B of the side slope.

[0072] Figure 6 A cross-sectional schematic diagram of a bulk acoustic resonator according to another exemplary embodiment of the present invention.

[0073] like Figure 6 As shown, the resonator includes the aforementioned substrate 1, acoustic mirror 2, first to third seed layers 3, 10 and 11, first bottom electrode layer 4, temperature compensation layer 5, second bottom electrode layer 6, piezoelectric layer 7, top electrode 8, and passivation layer 9. The electrode connection end of the top electrode 8 is provided with a bridge portion, which defines a bridge gap 12, and the non-electrode connection end of the top electrode 8 is provided with a cantilever, which defines a cantilever gap 13.

[0074] like Figure 6 As shown, the projection of the inner edge of the cantilever gap 13 in the vertical direction lies on the inclined surface of the left side of the temperature compensation layer, that is, on... Figure 6 In the structure shown, the inner edge of the cantilever gap 13 is located horizontally between the upper edge 5A and the lower edge 5B of the left side slope; the projection of the inner edge of the bridge gap 12 in the vertical direction is located on the right side slope of the thermal compensation layer, that is, on... Figure 6 In the structure shown, the inner edge of the bridge gap 12 is located in the horizontal direction between the upper edge 5A and the lower edge 5B of the right side slope.

[0075] It should also be noted that although the wing bridge structure of the non-electrode connection end of the top electrode is shown in the form of a cantilever, the wing bridge structure is not limited to a cantilever, but can also be a bridge provided at the non-electrode connection end of the top electrode.

[0076] Furthermore, although not shown, when a gap is defined between the wing bridge portion of the top electrode along the effective region of the resonator and the piezoelectric layer, and the inner edge of the gap lies horizontally between the boundary of the acoustic mirror and the edge of the temperature-compensating layer, there are three acoustic impedance mismatch points in the effective region, corresponding to the upper and lower edges of the temperature-compensating layer and the inner edge of the gap. In this case, transverse sound waves will undergo three reflections at these three acoustic impedance mismatch points, thereby confining more transverse wave energy within the effective region of the resonator, increasing the Q value.

[0077] In the above-described embodiment of the present application, the temperature compensating layer 5 is located inside the boundary of the acoustic mirror 2 in the horizontal direction, but the present application is not limited to this. For example, the upper end edge 5A of the temperature compensating layer 5 is located inside the boundary of the acoustic mirror 2 in the horizontal direction, and the lower end edge 5B is located outside the boundary of the acoustic mirror 2 in the horizontal direction.

[0078] Note that in the present application, each numerical range, except for the case where it is explicitly stated that the end point value is not included, can be the median value of the numerical range in addition to the end point value, and these are all within the scope of the present application.

[0079] In the present application, upper and lower are relative to the bottom surface of the substrate of the resonator, and for a component, the side close to the bottom surface is the lower side, and the side away from the bottom surface is the upper side.

[0080] In the present application, inner and outer are relative to the center of the effective area (the effective area is constituted by the overlapping area of the piezoelectric layer, the top electrode, the bottom electrode, and the acoustic mirror in the thickness direction of the resonator) of the resonator (i.e., the center of the effective area) in the lateral direction or the radial direction, and for a component, the side or the end close to the center of the effective area is the inner side or the inner end, and the side or the end away from the center of the effective area is the outer side or the outer end. For a reference position, the inner side of the position indicates between the position and the center of the effective area in the lateral direction or the radial direction, and the outer side of the position indicates further away from the center of the effective area than the position in the lateral direction or the radial direction.

[0081] As will be appreciated by those skilled in the art, the bulk acoustic wave resonator according to the present application can be used to form a filter or other semiconductor device.

[0082] Based on the above, the present application proposes the following technical solutions:

[0083] 1. A bulk acoustic wave resonator, comprising:

[0084] a substrate;

[0085] an acoustic mirror;

[0086] a bottom electrode;

[0087] a top electrode; and

[0088] a piezoelectric layer disposed between the bottom electrode and the top electrode,

[0089] wherein:

[0090] the resonator further comprises a temperature compensating layer disposed in the piezoelectric layer or in the bottom electrode or between the piezoelectric layer and the bottom electrode, and an edge portion of the temperature compensating layer has a bevel, the bevel has an upper end edge and a lower end edge, and the lower end edge is located outside the upper end edge in the horizontal direction; and

[0091] The top electrode is provided with a wing bridge portion along an effective area of the resonator, and a gap is defined between the wing bridge portion and the piezoelectric layer, an inner edge of the gap being between the upper end edge and the lower end edge in the horizontal direction.

[0092] 2. The resonator according to 1, wherein:

[0093] The wing bridge portion includes a connection end bridge portion provided at an electrode connection end of the top electrode, and the gap includes a connection end bridge portion gap defined by the connection end bridge portion.

[0094] 3. The resonator according to 1 or 2, wherein:

[0095] The wing bridge portion includes a suspension wing provided at a non-electrode connection end of the top electrode, and the gap includes a suspension wing gap defined by the suspension wing; or

[0096] The wing bridge portion includes a non-connection end bridge portion provided at a non-electrode connection end of the top electrode, and the gap includes a non-connection end bridge portion gap defined by the non-connection end bridge portion.

[0097] 4. The resonator according to 3, wherein:

[0098] An outer edge of the suspension wing gap is inside the lower end edge in the horizontal direction, or

[0099] An outer edge of the non-connection end bridge portion gap is inside the lower end edge in the horizontal direction.

[0100] 5. The resonator according to 3, wherein:

[0101] An outer edge of the suspension wing gap is outside the lower end edge in the horizontal direction, or

[0102] An outer edge of the non-connection end bridge portion gap is outside the lower end edge in the horizontal direction.

[0103] 6. The resonator according to 1, wherein:

[0104] The bottom electrode includes a first bottom electrode layer and a second bottom electrode layer, and the temperature compensating layer is provided between the first bottom electrode layer and the second bottom electrode layer.

[0105] 7. The resonator according to 1, wherein:

[0106] The temperature compensating layer is inside a boundary of the acoustic mirror in the horizontal direction.

[0107] 8. The resonator according to 1, wherein:

[0108] The upper end edge is inside the boundary of the acoustic mirror in the horizontal direction, and the lower end edge is outside the boundary of the acoustic mirror in the horizontal direction.

[0109] 9. The resonator according to claim 1, wherein:

[0110] The upper end edge and the lower end edge have a bevel length therebetween;

[0111] On the bevel, an inner edge of the gap is in a position range whose inside is within one third to one fourth of the bevel length from the upper end edge, and whose outside is within one third to one fourth of the bevel length from the lower end edge.

[0112] 10. The resonator according to claim 1, wherein:

[0113] An acute angle formed by the bevel and a bottom surface of the temperature compensating layer is less than 15 degrees.

[0114] 11. A bulk acoustic wave resonator comprising:

[0115] a substrate;

[0116] an acoustic mirror;

[0117] a bottom electrode;

[0118] a top electrode; and

[0119] a piezoelectric layer provided between the bottom electrode and the top electrode,

[0120] wherein:

[0121] the resonator further comprises a temperature compensating layer provided in the piezoelectric layer or in the bottom electrode or between the piezoelectric layer and the bottom electrode;

[0122] the temperature compensating layer is inside the boundary of the acoustic mirror in the horizontal direction; and

[0123] the top electrode is provided with a wing bridge portion along an effective area of the resonator, a gap is defined between the wing bridge portion and the piezoelectric layer, and an inner edge of the gap is between the boundary of the acoustic mirror and an edge of the temperature compensating layer in the horizontal direction.

[0124] 12. A filter comprising the bulk acoustic wave resonator according to any one of claims 1 to 11.

[0125] 13. An electronic device comprising the filter according to claim 12 or the bulk acoustic wave resonator according to any one of claims 1 to 11.

[0126] The electronic devices herein include, but are not limited to, intermediate products such as radio frequency front ends, filter amplification modules, and terminal products such as mobile phones, WIFI, and unmanned aerial vehicles.

[0127] Although embodiments of the present application have been shown and described, it is to be understood that the application is not limited to these embodiments. Since modifications can be made in these embodiments without departing from the spirit and scope of the application, the application is not limited except by the appended claims, the full scope of which is to be determined by reference to the claims and equivalents thereof.

Claims

1. A bulk acoustic wave resonator, comprising: a substrate; an acoustic mirror; a bottom electrode; a top electrode; and a piezoelectric layer disposed between the bottom electrode and the top electrode, wherein: the resonator further comprises a temperature compensation layer disposed in the piezoelectric layer or in the bottom electrode or between the piezoelectric layer and the bottom electrode, and an edge portion of the temperature compensation layer has a bevel, the bevel has an upper end edge and a lower end edge, the lower end edge is outside the upper end edge in a horizontal direction; and the top electrode is provided with a wing bridge portion along an effective area of the resonator, a gap is defined between the wing bridge portion and the piezoelectric layer, and an inner edge of the gap is between the upper end edge and the lower end edge in the horizontal direction. 2.The resonator according to claim 1, wherein: the wing bridge portion comprises a connection end bridge portion provided at a connection end of the top electrode, and the gap comprises a gap defined by the connection end bridge portion. 3.The resonator according to claim 1 or 2, wherein: the wing bridge portion comprises a wing provided at a non-connection end of the top electrode, and the gap comprises a wing gap defined by the wing; or the wing bridge portion comprises a non-connection end bridge portion provided at a non-connection end of the top electrode, and the gap comprises a non-connection end bridge portion gap defined by the non-connection end bridge portion. 4.The resonator according to claim 3, wherein: an outer edge of the wing gap is inside the lower end edge in the horizontal direction, or an outer edge of the non-connection end bridge portion gap is inside the lower end edge in the horizontal direction. 5.The resonator according to claim 3, wherein: an outer edge of the wing gap is outside the lower end edge in the horizontal direction, or an outer edge of the non-connection end bridge portion gap is outside the lower end edge in the horizontal direction. 6.The resonator according to claim 1, wherein: the bottom electrode comprises a first bottom electrode layer and a second bottom electrode layer, and the temperature compensation layer is disposed between the first bottom electrode layer and the second bottom electrode layer. 7.The resonator according to claim 1, wherein: the temperature compensation layer is inside a boundary of the acoustic mirror in the horizontal direction. 8.The resonator according to claim 1, wherein: the upper end edge is inside the boundary of the acoustic mirror in the horizontal direction, and the lower end edge is outside the boundary of the acoustic mirror in the horizontal direction. 9.The resonator according to claim 1, wherein: a length of the bevel is between the upper end edge and the lower end edge; on the bevel, an inner edge of the gap is at a position range, an inside of the position range is within one third to one fourth of the length of the bevel from the upper end edge, and an outside of the position range is within one third to one fourth of the length of the bevel from the lower end edge. 10.The resonator according to claim 1, wherein: an acute angle formed by the bevel and a bottom surface of the temperature compensation layer is less than 15 degrees. 11.A bulk acoustic wave resonator, comprising: a substrate; an acoustic mirror; a bottom electrode; a top electrode; and a piezoelectric layer disposed between the bottom electrode and the top electrode, wherein: The resonator further comprises a temperature compensation layer, which is arranged in the piezoelectric layer or in the bottom electrode or between the piezoelectric layer and the bottom electrode; The temperature compensation layer is located inside the boundary of the acoustic mirror in the horizontal direction; and The top electrode is provided with a wing bridge portion along the effective area of the resonator, a gap is defined between the wing bridge portion and the piezoelectric layer, and the inner edge of the gap is located between the boundary of the acoustic mirror and the edge of the temperature compensation layer in the horizontal direction.

12. A filter comprising the bulk acoustic wave resonator according to any one of claims 1-11.

13. An electronic device comprising the filter according to claim 12 or the bulk acoustic wave resonator according to any one of claims 1-11.

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