Heat dissipation structure, bulk acoustic wave resonator with heat dissipation structure, filter and electronic device

Abstract

The present invention relates to a bulk acoustic wave resonator, comprising a substrate having a first surface, a second surface and a through hole; an acoustic mirror; a bottom electrode arranged above the substrate; a top electrode, opposite to the bottom electrode; a piezoelectric layer arranged above the bottom electrode and between the bottom electrode and the top electrode; and a heat dissipation structure. The area where the acoustic mirror, the bottom electrode, the piezoelectric layer and the top electrode overlap in the thickness direction of the substrate is the effective area of ​​the resonator, and the bottom electrode, the piezoelectric layer and the top electrode are arranged on the first surface of the substrate; the heat dissipation structure comprises a heat dissipation part, a heat extraction part and a thermal connection part that thermally connects the heat dissipation part to the heat extraction part, and the heat extraction part is located outside the effective area and is in thermal contact with the edge area of ​​the effective area; the heat dissipation part comprises a second heat dissipation part arranged on the side where the second surface of the substrate is located; the thermal connection part passes through the through hole of the substrate in the thickness direction of the substrate to conduct heat from the heat extraction part to the second heat dissipation part. The present invention also relates to filters and electronic devices.

Description

Technical Field

[0001] Embodiments of the present invention relate to an acoustic wave resonator, and more particularly to a heat dissipation structure for a semiconductor device, a bulk acoustic wave resonator, a filter having the resonator, and an electronic device having the filter. Background Art

[0002] Thin film bulk wave resonators, made by longitudinal resonance of piezoelectric thin films in the thickness direction, have become a viable alternative to surface acoustic wave devices and quartz crystal resonators in machine communications and high-speed serial data applications. RF front-end bulk wave filters / duplexers provide superior filtering characteristics, such as low insertion loss, steep transition bands, large power handling, and strong anti-electrostatic discharge (ESD) capabilities. High-frequency thin film bulk wave oscillators with ultra-low frequency temperature drift have low phase noise, low power consumption, and a large bandwidth modulation range. In addition, these miniature thin film resonators use CMOS-compatible processing technology on silicon substrates, which can reduce unit costs and facilitate eventual integration with CMOS circuits.

[0003] The bulk wave resonator consists of an acoustic mirror and two electrodes, and a layer of piezoelectric material called a piezoelectric excitation located between the two electrodes. The bottom electrode and the top electrode are also called the excitation electrodes, and their function is to cause mechanical oscillations in the layers of the resonator. The acoustic mirror forms an acoustic isolation between the bulk wave resonator and the substrate to prevent the sound waves from being transmitted outside the resonator and causing energy loss.

[0004] Theoretically, when a BAW resonator is working, there is only mutual conversion between mechanical energy and electrical energy. However, in reality, the electrical energy and sound waves in the BAW resonator are always inevitably partially converted into heat energy, and the higher the frequency of the resonator, the more significant the heating effect will become. Since the thickness of the key components of the BAW resonator, namely the piezoelectric film and electrodes, is only at the micrometer or nanometer level, the accumulation of heat in them will bring significant negative effects, such as causing the resonator temperature to rise and cause the resonator frequency to drift, or causing stress accumulation and deformation of the piezoelectric stack, thereby affecting the reliability and life of the resonator, and limiting the further improvement of the resonator's power capacity. Summary of the invention

[0005] Constructing a heat dissipation structure and transferring the heat through the heat dissipation structure to the outside of the resonant structure in a timely manner is an effective method to reduce the impact of heat on the resonator. Constructing a heat dissipation structure can make the resonator have higher reliability and higher power capacity.

[0006] The present invention is proposed to alleviate or solve at least one aspect of the heat dissipation problem of the resonator in the prior art.

[0007] According to one aspect of an embodiment of the present invention, a bulk acoustic wave resonator is proposed, comprising: a substrate having a first surface and a second surface and a through hole passing through the substrate; an acoustic mirror; a bottom electrode arranged above the substrate; a top electrode opposite to the bottom electrode; a piezoelectric layer arranged above the bottom electrode and between the bottom electrode and the top electrode; and a heat dissipation structure, wherein: the area where the acoustic mirror, the bottom electrode, the piezoelectric layer and the top electrode overlap in the thickness direction of the substrate is the effective area of ​​the resonator, and the bottom electrode, the piezoelectric layer and the top electrode are arranged on the first surface of the substrate; the heat dissipation structure comprises a heat dissipation portion, a heat extraction portion and a thermal connection portion that thermally connects the heat dissipation portion with the heat extraction portion, the heat extraction portion is located outside the effective area, and the heat extraction portion is in thermal contact with the edge area of ​​the effective area; the heat dissipation portion comprises a second heat dissipation portion arranged on the side where the second surface of the substrate is located; the thermal connection portion passes through the through hole of the substrate in the thickness direction of the substrate to conduct heat from the heat extraction portion to the second heat dissipation portion.

[0008] Optionally, the heat dissipation portion further includes a first heat dissipation portion, which is disposed on the side where the first surface is located and is directly thermally connected to the heat extraction portion.

[0009] Optionally, the BAW resonator further includes a first heat-conducting insulating medium layer; the heat extraction portion is arranged on one side of the first surface of the substrate, the first heat-conducting insulating medium layer is arranged between the bottom electrode and the heat extraction portion, and the bottom electrode is located above the first heat-conducting insulating medium layer, keeps contact with the first heat-conducting insulating medium layer and is separated from the heat extraction portion. Further, the first heat-conducting insulating medium layer is made of aluminum nitride, beryllium oxide or silicone grease.

[0010] Optionally, the heat extraction portion is an insulating portion; the heat extraction portion is arranged on one side of the first surface of the substrate, and the bottom electrode is located above the heat extraction portion and maintains contact with the heat extraction portion.

[0011] Optionally, the heat extraction portion extends to the upper surface of the piezoelectric layer and maintains contact with the piezoelectric layer while being spaced apart from the top electrode.

[0012] Optionally, the BAW resonator further includes a second heat-conducting insulating medium layer; the heat extraction portion extends along the upper surface of the piezoelectric layer to below the second heat-conducting insulating medium layer and maintains contact with the second heat-conducting insulating medium layer; the top electrode is located above the second heat-conducting insulating medium layer, maintains contact with the second heat-conducting insulating medium layer and is spaced apart from the heat extraction portion. Furthermore, the second heat-conducting insulating medium layer is made of aluminum nitride, beryllium oxide or silicone grease.

[0013] Optionally, the heat extraction portion is an insulating portion; the heat extraction portion extends along the upper surface of the piezoelectric layer to below the top electrode, and the top electrode is located above the heat extraction portion and maintains contact with the heat extraction portion.

[0014] Optionally, the first heat dissipation portion is at least partially arranged around the effective area. Further, the first heat dissipation portion and / or the second heat dissipation portion includes a portion in contact with air to exchange heat with the air and / or a portion arranged in the substrate to contact the substrate to exchange heat with the substrate.

[0015] In an optional embodiment, the through hole can be a circular through hole, whose diameter can range from 1-30μm, and further optionally range from 5-20μm; or the through hole can be a rectangular through hole, in whose cross section, the rectangular length ranges from 20-80μm, and further ranges from 40-60μm; the width can range from 2-20μm, and further optionally ranges from 5-10μm.

[0016] Optionally, the first heat dissipation portion and / or the second heat dissipation portion comprises a plurality of strip-shaped protrusions. Further, the strip-shaped protrusions are distributed at equal intervals, each strip-shaped protrusion has the same width, the width range is 0.5-4 μm, the interval between two adjacent strip-shaped protrusions ranges from 0.5-6 μm, and the height range of the strip-shaped protrusions ranges from 0.5-20 μm.

[0017] Optionally, the first heat dissipation part and / or the second heat dissipation part includes a plurality of columnar protrusions. Further, the columnar protrusions are regular hexagonal prism protrusions; the columnar protrusions are evenly spaced, and the side lengths of each regular hexagonal prism structure are the same, and the side length range is 0.5-4μm; the regular hexagonal prism structures are evenly spaced, and the spacing between two adjacent regular hexagonal prisms is 0.5-6μm; the height range of the regular hexagonal prism protrusions is 0.5-20μm.

[0018] Optionally, the multiple columnar protrusions form a dissipation structure for heat transfer. Furthermore, the columnar protrusions are cylindrical protrusions, and the multiple columnar protrusions are distributed in concentric circles; the radius of the columnar protrusions gradually decreases in the radial outward direction, and the number of columnar protrusions in each circle formed by the columnar protrusions gradually increases; the radius of the columnar protrusions of two adjacent circles satisfies the geometric law, and the ratio of the radius of the columnar protrusions of the inner circle to the radius of the columnar protrusions of the outer circle is α1; the number of columnar protrusions of two adjacent circles satisfies the geometric law, and the ratio of the number of columnar protrusions of the outer circle to the number of columnar protrusions of the inner circle is α2, and α2 / α1 is greater than 1, wherein: the maximum value of the radius of the columnar protrusion ranges from 4 to 30 μm, and the minimum value of the number of columnar protrusions in a circle ranges from 8 to 16.

[0019] Optionally, the first heat dissipation portion and / or the second heat dissipation portion includes a plurality of annular protrusions in a concentric circle structure.

[0020] Optionally, the plurality of annular protrusions form a heat transfer dissipation structure. Further, the width of the annular protrusions and the spacing between adjacent annular protrusions satisfy: (1) gradually narrowing outward along the radius of the annular protrusion; (2) the spacing between two adjacent annular protrusions satisfies the geometric law, and the width ratio of the outer annular protrusion to the inner annular protrusion is greater than 0 and less than 1; or, the spacing between two adjacent annular protrusions satisfies the arithmetic difference law, and the width difference between the outer annular protrusion and the inner annular protrusion is b, and the range of b is 0.1-0.5μm, wherein: the maximum value of the width of the annular protrusion is in the range of 2-20μm, and the maximum value of the spacing between the annular protrusions is in the range of 4-40μm.

[0021] Optionally, in the above BAW resonator, a lateral distance between the heat extraction portion and the effective area is not less than 10 acoustic wave wavelengths.

[0022] Optionally, the second heat dissipation portion covers the second surface of the substrate; and all thermal connection portions are connected to the second heat dissipation portion.

[0023] An embodiment of the present invention also relates to a heat dissipation structure of a semiconductor device, wherein the semiconductor device has a substrate, the substrate has a first surface and a second surface, the substrate has a through hole penetrating the substrate in the thickness direction, and the first surface of the substrate is provided with a functional component, wherein: the heat dissipation structure includes a heat dissipation portion, a heat extraction portion and a thermal connection portion, the heat extraction portion is provided on the side where the first surface is located, the heat dissipation portion includes a second heat dissipation portion provided on the side where the second surface of the substrate is located, and the thermal connection portion passes through the substrate via the through hole; and the heat extraction portion is suitable for conducting heat from the functional component to the second heat dissipation portion via the thermal connection portion. Optionally, the heat dissipation portion also includes a first heat dissipation portion, the first heat dissipation portion is provided on the side where the first surface is located and is directly thermally connected to the heat extraction portion. Optionally, the semiconductor device is a bulk acoustic wave resonator, and the heat extraction portion is suitable for conducting heat from the effective acoustic region of the resonator. Optionally, the heat dissipation portion forms a dissipation structure for heat transfer.

[0024] An embodiment of the present invention further relates to a filter, comprising the above-mentioned BAW resonator or dissipative structure. Optionally, the filter comprises a plurality of the above-mentioned BAW resonators; the thermal connection part is provided in the gap between at least some adjacent resonators, or at least some adjacent resonators share the thermal connection part.

[0025] An embodiment of the present invention further relates to an electronic device, comprising the above-mentioned filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The following description and accompanying drawings may better help understand these and other features and advantages of various embodiments disclosed by the present invention, in which the same reference numerals always represent the same components, wherein:

[0027] Figure 1A and Figure 1B 1 and 2 are respectively a schematic top view and a cross-sectional view along the AA direction of a resonator with a heat dissipation structure according to an exemplary embodiment of the present invention, Figure 1B The MT region is shown in the figure;

[0028] Figure 2 is a cross-sectional schematic diagram of a resonator with a heat dissipation structure according to an exemplary embodiment of the present invention, wherein the MT region is shown;

[0029] Figure 3 A cross-sectional schematic diagram of a resonator with a heat dissipation structure according to another exemplary embodiment of the present invention, wherein an MT region is shown;

[0030] Figure 4 A cross-sectional schematic diagram of a resonator with a heat dissipation structure according to another exemplary embodiment of the present invention, wherein an MT region is shown;

[0031] Figure 5A and Figure 5B 1 are respectively a schematic top view of a resonator with a heat dissipation structure according to an exemplary embodiment of the present invention and a partial enlarged view of the MA region;

[0032] Fig. 6A and Figure 6B 1 are respectively a schematic top view of a resonator with a heat dissipation structure according to an exemplary embodiment of the present invention and a partial enlarged view of the MA region;

[0033] Fig. 7A and Figure 7B 1 are respectively a schematic top view of a resonator with a heat dissipation structure according to an exemplary embodiment of the present invention and a partial enlarged view of the MA region;

[0034] Fig. 8A and Figure 8B 1 are respectively a schematic top view of a resonator with a heat dissipation structure according to an exemplary embodiment of the present invention and a partial enlarged view of the MA region;

[0035] Fig. 9A is a schematic diagram of a filter composed of a plurality of resonators according to an exemplary embodiment of the present invention;

[0036] Fig. 9B According to an exemplary embodiment of the present invention, Fig. 9A A schematic cross-sectional view taken along AOA' in FIG.

[0037] Fig. 9C According to another exemplary embodiment of the present invention, Fig. 9A A schematic cross-sectional view taken along AOA' in FIG.

[0038] Fig.9D According to another exemplary embodiment of the present invention, Fig. 9A A schematic cross-sectional view taken along AOA' in FIG.

[0039] Fig. 10A is a cross-sectional schematic diagram of a resonator with a heat dissipation structure according to an exemplary embodiment of the present invention, wherein the MS region is shown;

[0040] Fig. 10B FIG. 4 is a schematic cross-sectional view of a resonator with a heat dissipation structure according to another exemplary embodiment of the present invention, in which the MS region is shown. DETAILED DESCRIPTION

[0041] The technical solution of the present invention is further specifically described below by examples and in conjunction with the accompanying drawings. In the specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the overall inventive concept of the present invention and should not be construed as a limitation of the present invention.

[0042] The present invention constructs a contact interface between the heat dissipation structure and the acoustic part (i.e., the effective area) AR of the resonator, and constructs a microstructure (further, a dissipation structure) that can increase the heat dissipation area on the interface between the heat dissipation part (e.g., the metal layer) of the heat dissipation structure and the air, and on the interface between the heat dissipation part and the substrate. At the same time, through the through holes provided on the substrate and the thermal connection parts passing through the through holes, the back side (the second surface) of the substrate can be provided with a heat dissipation surface, which can greatly improve the heat transfer efficiency of the heat dissipation structure.

[0043] Compared with setting the heat dissipation structure only on one side, the technical solution of the present invention can form a larger heat dissipation area in the case of a single resonator. At the same time, when the front side of the substrate is not suitable for placing the heat dissipation surface (such as when multiple resonators form a filter structure), the metal-air interface (heat dissipation surface) and the metal-substrate interface (heat dissipation surface) can still form a considerable heat dissipation area on the back side of the substrate.

[0044] The BAW resonator according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 10 .

[0045] Refer to the following Figure 1A and Figure 1B The overall structure of a BAW resonator is exemplified. Figure 1A and Figure 1B1 and 2 are respectively a schematic top view and a cross-sectional view along the AA direction of a resonator with a heat dissipation structure according to an exemplary embodiment of the present invention, Figure 1B The MT region is shown in FIG. Figure 1A and 1B As shown, the resonator generally includes a resonator part and a heat dissipation structure part. The components of the resonator include: a substrate 100 , an acoustic mirror 101 , a bottom electrode 102 , a piezoelectric film 103 (corresponding to a piezoelectric layer) and a top electrode 104 . Among them: the materials that can be used for the substrate 100 include but are not limited to: single crystal silicon (Si), gallium arsenide (GaAs); sapphire, etc., the materials that can be used for the electrodes 102 and 104 include but are not limited to: molybdenum (Mo), ruthenium (Ru), aluminum (Al), etc.; the acoustic mirror can adopt an air cavity structure or a Bragg reflection layer structure or other various equivalent structures that can achieve acoustic isolation effects, wherein the Bragg reflection layer structure is composed of low acoustic resistance and high acoustic resistance materials periodically alternating, and the low acoustic resistance materials include but are not limited to: silicon dioxide (SiO2), molybdenum (Mo), etc., and the high acoustic resistance materials include but are not limited to tungsten (Wu), aluminum nitride (AlN), etc.; the material of the piezoelectric film 103 can be selected from aluminum nitride (AlN), lead zirconate titanate (PZT) and doped aluminum nitride (AlRN) with a certain atomic ratio, wherein the doped element R includes but is not limited to: scandium (Sc), magnesium (Mg), titanium (Ti), etc. The effective acoustic area AR of the resonator is defined by the lateral overlapping portion where the acoustic mirror 101, the lower electrode bottom electrode 102, the piezoelectric layer 103 and the upper electrode top electrode are in contact with each other.

[0046] The components of the heat dissipation structure include: a heat-conducting medium layer 105 and heat-conducting metal layers 106 and 107, and a thermal connection portion (or a through-hole structure, which can be composed of a heat-conducting metal passing through the through-hole) disposed in the substrate. The aperture DH1 of the through-hole 108 ranges from 50 μm to 200 μm, and at least one edge of the acoustic structure polygon of the bulk acoustic wave resonator has a through-hole on the outside. The metal layers 106 and 107 are connected by the metal filled in the through-hole 108.

[0047] The material of the dielectric layer 105 may be selected from, but not limited to, aluminum nitride (AlN), beryllium oxide (BeO), silicone grease, etc. The material used for the dielectric layer should have good thermal conductivity and insulation; the material of the metal layer 106 includes, but is not limited to, copper (Cu), aluminum (Al), molybdenum (Mo), gold (Au), etc.

[0048] In an optional embodiment, the inner edge of the metal layer 106 is located outside the effective acoustic region AR and maintains a distance from the boundary of the acoustic region, and the distance is not less than 10 acoustic wavelengths.

[0049] It should be noted that the heat-conducting metal layer of the heat dissipation structure may also be replaced by a non-metallic heat-conducting material, and in the case where the heat dissipation structure is made of a non-conductive heat-conducting material, the heat-conducting medium layer may not be provided.

[0050] As shown in the figure, the heat dissipation structure has a heat extraction portion in contact with the peripheral portion of the active area AR and a heat dissipation portion in contact with the heat extraction portion. The heat extraction portion can be considered as a portion of the heat dissipation structure within the area indicated by MT.

[0051] like Figure 1B As shown, the BAW resonator with a heat dissipation structure has five key contact areas, namely, the contact area MT where the heat dissipation structure contacts the peripheral part or edge area of ​​the acoustic part (effective area) of the resonator, the heat dissipation structure and the substrate contact areas MS1 and MS2, and the heat dissipation structure and the air contact areas MA1 and MA2.

[0052] Based on the above, an embodiment of the present invention proposes a bulk acoustic wave resonator, comprising: a substrate having a first surface and a second surface and a through hole passing through the substrate; an acoustic mirror; a bottom electrode arranged above the substrate; a top electrode, opposite to the bottom electrode; a piezoelectric layer arranged above the bottom electrode and between the bottom electrode and the top electrode; and a heat dissipation structure, wherein: the area where the acoustic mirror, the bottom electrode, the piezoelectric layer, and the top electrode overlap in the thickness direction of the substrate is the effective area of ​​the resonator, and the bottom electrode, the piezoelectric layer, and the top electrode are arranged on the first surface of the substrate; the heat dissipation structure comprises a heat dissipation portion, a heat extraction portion, and a thermal connection portion that thermally connects the heat dissipation portion with the heat extraction portion, the heat extraction portion is located outside the effective area, and the heat extraction portion is in thermal contact with the edge area of ​​the effective area; the heat dissipation portion comprises a second heat dissipation portion arranged on the side where the second surface of the substrate is located; the thermal connection portion passes through the through hole of the substrate in the thickness direction of the substrate to conduct heat from the heat extraction portion to the second heat dissipation portion.

[0053] In the above solution, the second heat dissipation part is established through the through-hole structure. In this way, on the one hand, the heat dissipation area can be significantly expanded; on the other hand, when the structural conditions do not allow the placement of the first heat dissipation part, the second heat dissipation part can provide a considerable heat dissipation area on the back of the substrate.

[0054] A through hole that is too narrow will result in low heat conduction efficiency, while a through hole that is too large will hinder the structural arrangement of other resonators. Therefore, the present invention sets the through hole size range as follows:

[0055] For circular through holes, the diameter range can be 1-30 μm, and the further optional range is 5-20 μm;

[0056] For the rectangular through hole, in the cross section, the rectangular length may range from 20 to 80 μm, and may further optionally range from 40 to 60 μm; the width may range from 2 to 20 μm, and may further optionally range from 5 to 10 μm.

[0057] Figure 2 FIG. 4 is a schematic cross-sectional view of a resonator with a heat dissipation structure according to an exemplary embodiment of the present invention, in which an MT region is shown.

[0058] like Figure 2 As shown, the overall structure of the resonator example with a heat dissipation structure is as follows: an acoustic mirror 201 (a specific example is a cavity structure) and a metal layer structure 206 are provided on the upper surface of a substrate 200. The cavity or acoustic mirror 201 passes through the metal layer 206 and is partially embedded in the substrate 200. An insulating dielectric layer 205 is provided above the cavity, which laterally spans the entire cavity and extends to the upper surface of the metal layer 206 to maintain contact therewith. The bottom electrode 202 is located above the insulating dielectric layer 205 and maintains contact with the insulating dielectric layer 205. Laterally, the bottom electrode 202 spans the entire cavity or acoustic mirror 201, but the bottom electrode 202 falls within the range of the insulating dielectric layer 205 as a whole. The piezoelectric film 203 is located above the bottom electrode and maintains contact with the upper surface of the bottom electrode. In addition, the piezoelectric film 203 extends beyond the bottom electrode 202 in the lateral direction and maintains contact with the insulating dielectric layer 205 and a portion of the upper surface of the metal layer 206, and the piezoelectric film 203 completely covers the insulating dielectric layer 205 and the bottom electrode 202. The top electrode 204 is located above the piezoelectric film 203 and maintains contact with the upper surface of 203. At the same time, the top electrode 204 falls into the cavity 201 in the lateral direction.

[0059] The overlapping area of ​​the top electrode 204, the piezoelectric film 203, the bottom electrode 202, and the cavity or acoustic mirror 201 in the lateral direction defines the effective piezoelectric effect area (effective area) AR of the resonator. The lower surface of the metal layer 206 remains in contact with the substrate and extends beyond the range of the piezoelectric film 203 in the lateral direction, and the metal layer 206 completely falls outside the area AR. Figure 2 As shown, metal layer 206 extends to the back side (second surface) of substrate 200 through the vias.

[0060] Based on the above and Figure 2 The heat dissipation portion further includes a first heat dissipation portion, which is arranged on the side where the first surface is located and is directly thermally connected to the heat extraction portion.

[0061] Based on the above, the BAW resonator according to the embodiment of the present invention may further include a first heat-conducting insulating medium layer; the heat extraction portion is arranged on one side of the first surface of the substrate, the first heat-conducting insulating medium layer is arranged between the bottom electrode and the heat extraction portion, and the bottom electrode is located above the first heat-conducting insulating medium layer, keeps contact with the first heat-conducting insulating medium layer and is spaced apart from the heat extraction portion. The first heat-conducting insulating medium layer may be made of aluminum nitride or silicone grease, for example.

[0062] In the case where no insulating dielectric layer is provided, the heat extraction portion is an insulating portion; and the heat extraction portion is provided on the substrate, and the bottom electrode is located above the heat extraction portion and keeps contact with the heat extraction portion.

[0063] Figure 3 FIG. 4 is a schematic cross-sectional view of a resonator with a heat dissipation structure according to another exemplary embodiment of the present invention, in which an MT region is shown.

[0064] like Figure 3 As shown, the overall structure of the resonator example with a heat dissipation structure is: an acoustic mirror 301 (an example is a cavity structure) is provided on the upper surface of the substrate 300, and the cavity or acoustic mirror 301 is embedded in the substrate 300. A bottom electrode 302 is provided above the cavity, and the bottom electrode 302 spans the entire cavity or acoustic mirror 301 and is partially in contact with the substrate 300. The piezoelectric film 303 is located above the bottom electrode and is in contact with the upper surface of the bottom electrode. In addition, the piezoelectric film 303 extends laterally beyond the range of the bottom electrode 302 and is partially in contact with the substrate 300. The top electrode 304 is located above the piezoelectric film 303 and is in contact with the upper surface of the piezoelectric film 303. At the same time, the top electrode 204 falls into the range of the cavity or acoustic mirror 301 laterally.

[0065] The overlapping area of ​​the top electrode 304, the piezoelectric film 303, the bottom electrode 302 and the cavity or acoustic mirror 301 in the lateral direction defines the effective piezoelectric effect area (effective area) AR of the resonator.

[0066] Part of the lower surface of the metal layer 306 remains in contact with the substrate and extends laterally beyond the range of the piezoelectric film 303, while another part of the lower surface of the metal layer 306 climbs upward along the outer inclined surface of the piezoelectric film 303 and covers the entire outer inclined surface of the piezoelectric film 303 and part of its upper horizontal surface. The metal layer 306 completely falls outside the area AR.

[0067] At the same time, if Figure 3 As shown, metal layer 306 extends to the back side (second surface) of substrate 300 through the vias.

[0068] Based on the above, in the BAW resonator according to the embodiment of the present invention, the heat extraction portion extends to the upper surface of the piezoelectric layer and keeps contact with the piezoelectric layer while being spaced apart from the top electrode.

[0069] Figure 4 FIG. 4 is a schematic cross-sectional view of a resonator with a heat dissipation structure according to another exemplary embodiment of the present invention, in which an MT region is shown.

[0070] like Figure 4 As shown in the figure, the overall structure of the resonator example with a heat dissipation structure is as follows: an acoustic mirror 401 (for example, a cavity structure) is provided on the upper surface of a substrate 400, and the acoustic mirror or cavity 401 is embedded in the substrate 400. A bottom electrode 402 is provided on the cavity, and the bottom electrode 402 spans the entire acoustic mirror or cavity 401 and is partially in contact with the substrate 400. A piezoelectric film 403 is located above the bottom electrode and is in contact with the upper surface of the bottom electrode. In addition, the piezoelectric film 403 extends beyond the range of the bottom electrode 402 in the lateral direction and is partially in contact with the substrate 400.

[0071] The overlapping area of ​​the top electrode 404, the piezoelectric film 403, the bottom electrode 402 and the acoustic mirror or cavity 401 in the lateral direction defines the effective piezoelectric effect area (effective area) AR of the resonator.

[0072] Part of the lower surface of the metal layer 406 remains in contact with the substrate and extends laterally beyond the range of the piezoelectric film 403, while another part of the lower surface of the metal layer 406 climbs upward along the outer inclined surface of the piezoelectric film 403 and covers the entire outer inclined surface of the piezoelectric film 403 and part of its upper horizontal surface. The metal layer 406 completely falls outside the area AR.

[0073] like Figure 4 As shown, metal layer 406 extends to the back side (second surface) of substrate 400 through the vias.

[0074] The upper surface of the metal layer 406 located at the upper plane of the piezoelectric film 403 is covered with an insulating dielectric layer 405 , and the insulating dielectric layer 405 falls outside the region AR.

[0075] The top electrode 404 is located above the piezoelectric film 403 and partially contacts the upper surface of the piezoelectric film 403. Meanwhile, the portion of the top electrode 404 contacting the piezoelectric film 403 falls into the acoustic mirror or cavity 401 in the lateral direction. Another portion of the lower surface of the top electrode contacts the insulating dielectric layer 405.

[0076] Based on the above, the BAW resonator according to the embodiment of the present invention may further include a second heat-conducting insulating medium layer; the heat extraction portion extends along the upper surface of the piezoelectric layer to below the second heat-conducting insulating medium layer and maintains contact with the second heat-conducting insulating medium layer; the top electrode is located above the second heat-conducting insulating medium layer, maintains contact with the second heat-conducting insulating medium layer and is spaced apart from the heat extraction portion. Optionally, the second heat-conducting insulating medium layer is made of aluminum nitride or silicone grease.

[0077] In the absence of an insulating dielectric layer, the heat extraction portion is an insulating portion; and the heat extraction portion extends along the upper surface of the piezoelectric layer to below the top electrode, and the top electrode is located above the heat extraction portion and maintains contact with the heat extraction portion.

[0078] Please refer to the attached Figures 5A-8B The contact area MA between the heat dissipation structure and the air is described exemplarily.

[0079] Figure 5A and Figure 5B 1 and 2 are respectively a schematic top view of a resonator with a heat dissipation structure according to an exemplary embodiment of the present invention and a local enlarged view of the MA region.

[0080] like Figure 5A As shown, the area of ​​the metal layer 506 is a circle with a radius of R500, and the range of R500 is 40-200 μm. In addition, the area of ​​the metal layer 506 can also be other geometric shapes that can enclose the acoustic part (effective area) of the resonator. The surface of the metal layer 506 in contact with the air in the MA area includes a plurality of strip-shaped protrusion structures, and the surfaces on both sides of each protrusion structure are effectively increased surface areas.

[0081] In addition, the lower surface of the substrate in this embodiment is also covered with a metal layer. The metal layer located on the lower surface of the substrate is Figure 5A Not shown.

[0082] Figure 5A The enlarged view of the local area Z501 in Figure 5B As shown: the band-shaped protrusion structures are distributed at equal intervals, and the width of each band-shaped protrusion structure is the same, which is D501, and the range of D501 is 0.5-4μm. The band-shaped protrusion structures are distributed at equal intervals, and the distance between two adjacent protrusions is D502, and the range of D502 is 0.5-6μm. The height of the band-shaped protrusion is H501, and the range of H501 is 0.5-20μm.

[0083] The metal-air interface characteristics described above belong to the MA1 region, and these characteristics are also applicable to the MA2 region.

[0084] Fig. 6A and Figure 6B1 and 2 are respectively a schematic top view of a resonator with a heat dissipation structure according to another exemplary embodiment of the present invention and a local enlarged view of the MA region.

[0085] like Fig. 6A As shown, the area of ​​the metal layer 606 is a circle with a radius of R600, and the range of R600 is 40-200μm. In addition, the area of ​​the metal layer 606 can also be other geometric shapes that can enclose the acoustic part (effective area) of the resonator. The surface of the metal layer 606 in contact with the air in the MA region includes a plurality of columnar protrusion structures, and the side surface of each protrusion structure is an effectively increased surface area. In this embodiment, the columnar structure is a regular hexagonal prism, but other shapes such as a circular cylinder, a rhombus column, a rectangular column, a triangular prism or other polygonal prisms are also feasible.

[0086] In addition, the lower surface of the substrate in this embodiment is also covered with a metal layer. The metal layer located on the lower surface of the substrate is Fig. 6A Not shown.

[0087] Fig. 6A The enlarged view of the local area Z601 in FIG. Figure 6B As shown: the side length of each regular hexagonal prism structure is the same, which is D601, and the range of D601 is 0.5-4μm. The regular hexagonal prism structures are evenly spaced, and the distance between two adjacent regular hexagonal prisms is D602, and the range of D602 is 0.5-6μm. The height of the regular hexagonal prism protrusion is H601, and the range of H601 is 0.5-20μm.

[0088] The metal-air interface characteristics described above belong to the MA1 region, and these characteristics are also applicable to the MA2 region.

[0089] Fig. 7A and Figure 7B 1 and 2 are respectively a schematic top view of a resonator with a heat dissipation structure according to yet another exemplary embodiment of the present invention and a local enlarged view of the MA region.

[0090] like Fig. 7A As shown, the area of ​​the metal layer 706 is a circle with a radius of R700, and the range of R700 is 40-200 μm. In addition, the area of ​​the metal layer 706 can also be other geometric shapes that can enclose the acoustic part (effective area) of the resonator. The surface of the metal layer 706 in contact with the air in the MA area includes concentric annular protrusion structures, and the side surface of each annular protrusion structure is an effectively increased surface area.

[0091] In addition, the lower surface of the substrate in this embodiment is also covered with a metal layer. The metal layer located on the lower surface of the substrate is Fig. 7A Not shown.

[0092] Fig. 7AThe enlarged view of the local area Z701 in Figure 7B is shown as follows: The width of the circular ring is D701, and the interval width or spacing between two adjacent circular rings is D702. The height of the circular ring protrusion is H701, and the range of H701 is 0.5 - 20 μm.

[0093] In a further embodiment, the distribution of the width D701 of the circular ring and the spacing D702 of the circular ring satisfies:

[0094] (1) It gradually becomes narrower outward along the radius of the circular ring;

[0095] (2) The spacing between two adjacent circular rings satisfies the geometric progression rule, and the width ratio of the outer ring to the inner ring is a (0 < a < 1), or the spacing between two adjacent circular rings satisfies the arithmetic progression rule, and the width difference between the outer ring and the inner ring is b, and the range of b is 0.1 - 0.5 μm;

[0096] Among them, the maximum value range of the width D701 of the circular ring is 2 - 20 μm, and the maximum value range of the spacing D702 of the circular ring is 4 - 40 μm.

[0097] The circular ring protrusion structure distributed according to the above rules can form a dissipative structure, that is, the farther away from the center of the circle, the larger the contact area between the metal layer 706 and the air, and the faster the heat dissipation speed. In this way, the gradient of the temperature field along the radius direction can be effectively increased, so that the heat in the resonator can be transmitted to the outside faster.

[0098] The metal-air interface characteristics described above belong to the MA1 region, and these characteristic descriptions also apply to the MA2 region.

[0099] Fig. 8A and Figure 8B are respectively the schematic top view of the resonator with a heat dissipation structure and the partial enlarged view of the MA region according to another exemplary embodiment of the present invention.

[0100] As Fig. 8A shown, in Embodiment A800, the region of the metal layer 806 is a circle with a radius of R800, and the range of R800 is 40 - 200 μm. In addition, the region of the metal layer 806 can also be other geometric shapes that can enclose the acoustic part (effective region) of the resonator therein. The surface of the metal layer 806 in contact with the air in the MA region can include a dissipative cylindrical array structure, and the side surface of each cylindrical protrusion structure is an effectively increased surface area.

[0101] In addition, the lower surface of the substrate in this embodiment is also covered with a metal layer, and the metal layer located on the lower surface of the substrate is Fig. 8A not shown in

[0102] Fig. 8A The enlarged view of the local area Z801 in Figure 8B As shown: the height of the cylindrical protrusion is H801, and the range of H801 is 0.5-20μm. The center distance between two adjacent circles of cylindrical protrusions is D801, and the range of D801 is 10-20μm.

[0103] Furthermore, the radius of the cylinder is R801 and the number of cylinders in each circle N satisfies:

[0104] (1) R801 gradually decreases outward along the radius R800 of the metal layer, while N gradually increases along this direction;

[0105] (2) The radii of the cylinders of two adjacent circles satisfy the geometric ratio rule, and the ratio of the inner cylinder radius to the outer cylinder radius is α1;

[0106] (3) The number of cylinders in two adjacent circles satisfies the geometric ratio rule, and the ratio of the number of cylinders in the outer circle to the number of cylinders in the inner circle is α2, and α2 / α1 is greater than 1;

[0107] (4) The maximum value range of R801 is 4-30μm, and the minimum value range of N is 8-16.

[0108] Since α2 / α1 is greater than 1, the final effect is that the farther away from the center of the metal layer 806, the larger the contact area with the air. Fig. 7A and 7B Similar to the example in, Fig. 8A and Figure 8B In the embodiment of the present invention, a dissipation structure that can improve the heat dissipation efficiency is also formed, and the cylindrical protrusion structure can provide a stronger dissipation effect than the circular ring structure, so theoretically Fig. 8A and Figure 8B The heat dissipation efficiency of the embodiment is better than Fig. 7A and 7B Examples in .

[0109] The metal-air interface characteristics described above belong to the MA1 region, and these characteristics are also applicable to the MA2 region.

[0110] Fig. 9A is a schematic diagram of a filter composed of a plurality of resonators according to an exemplary embodiment of the present invention; Fig. 9B According to an exemplary embodiment of the present invention, Fig. 9A A schematic cross-sectional view taken along AOA' in FIG. Fig. 9C According to another exemplary embodiment of the present invention, Fig. 9A A schematic cross-sectional view taken along AOA' in FIG. Fig.9D According to another exemplary embodiment of the present invention, Fig. 9A The schematic cross-sectional view of AOA' in FIG. Figures 9A-9DAn embodiment of an MA interface is described when a plurality of resonators constitute a filter.

[0111] Fig. 9A One example of an MA region when a plurality of resonators constitute a filter

[0112] Fig. 9A In the embodiment, when multiple resonators 110 form a filter in a two-dimensional topological structure, the metal-air interface 116 often cannot obtain sufficient distribution space on the front side of the substrate, especially when the gap between the resonators is particularly narrow. In this case, the metal structure can be extended to the back side of the substrate through the through hole 118 to form a metal-air interface 117.

[0113] Based on different embodiments, the filter may be cut open along the broken line AOA' in FIG. 9 to obtain the following cross-sectional view: Fig. 9B , Fig. 9C and Fig.9D .

[0114] like Fig. 9B As shown, in this embodiment, there are three adjacent resonator units 120, and the contact mode between the metal layer 126 and the acoustic resonance unit 120 is similar to Figure 2 The embodiments shown are the same. Fig. 9B In the embodiment, the metal-air interface on the front side of the substrate basically only exists between two adjacent resonant units and occupies only a very small area, and most of the metal-air interface 127 is formed on the back side of the substrate through the through hole 128. Figure 5A-Figure 8B All metal-air interface characteristics of the embodiments in apply to interface 127.

[0115] like Fig. 9C As shown, this embodiment has three adjacent resonator units 130, and the contact mode between the metal layer 136 and the acoustic resonance unit 130 is similar to that of Figure 3 In this embodiment, the metal-air interface on the front side of the substrate basically only exists between two adjacent resonant units and occupies only a small area, and most of the metal-air interface 137 is formed on the back side of the substrate through the through hole 138. Figure 5A-Figure 8B All metal-air interface characteristics of the embodiments in apply to interface 137.

[0116] like Fig.9D As shown, this embodiment has three adjacent resonator units 140, and the contact mode between the metal layer 146 and the acoustic resonance unit 140 is similar to Figure 4 In this embodiment, the metal-air interface on the front side of the substrate basically only exists between two adjacent resonant units and occupies only a small area, and most of the metal-air interface 147 is formed on the back side of the substrate through the through hole 148. Figure 5A-Figure 8B All metal-air interface characteristics of the embodiments in apply to interface 147.

[0117] Please refer to the attached Fig. 10A and Fig. 10B The contact area MS between the heat dissipation structure and the substrate is described exemplarily.

[0118] Fig. 10A is a cross-sectional schematic diagram of a resonator with a heat dissipation structure according to an exemplary embodiment of the present invention, wherein the MS region is shown; Fig. 10B FIG. 4 is a schematic cross-sectional view of a resonator with a heat dissipation structure according to another exemplary embodiment of the present invention, in which the MS region is shown.

[0119] exist Fig. 10A In the illustrated embodiment, the interface regions where the metal layer contacts the substrate are MS1 and MS2, which have structural details for the purpose of increasing the contact area between the metal layer and the substrate, thereby increasing the heat loss rate from the metal layer to the substrate.

[0120] Fig. 10B An exemplary embodiment of the MS region in the case of a filter structure is shown in FIG. 1 , in which only the MS2 region is present.

[0121] Fig. 10A and Fig. 10B The specific embodiment of the interface region MS between the metal and the substrate Figure 5A-Figure 8B The metal-air interface region MA described in the corresponding embodiment is the same as that described in the corresponding embodiment. Figure 5A-Figure 8B In the embodiments, the structure and specific parameters established on the upper surface of the metal layer are applied to the contact interface between the metal layer and the substrate.

[0122] As will be appreciated by those skilled in the art, Figure 5A-Figure 8B The upper surface structure of the heat dissipation part or the metal layer in the example can also be applied to the MS region, that is, applied to the contact interface between the heat dissipation part or the metal layer and the substrate.

[0123] In the present invention, the electrode composition material can be gold (Au), tungsten (W), molybdenum (Mo), platinum (Pt), ruthenium (Ru), iridium (Ir), titanium tungsten (TiW), aluminum (Al), titanium (Ti) and other similar metals. In the present invention, the piezoelectric layer material can be aluminum nitride (AlN), zinc oxide (ZnO), lead zirconate titanate (PZT), lithium niobate (LiNbO3), quartz (Quartz), potassium niobate (KNbO3) or lithium tantalate (LiTaO3) and other materials.

[0124] Based on the above, an embodiment of the present invention also relates to a heat dissipation structure of a semiconductor device, wherein the semiconductor device has a substrate, the substrate has a first surface and a second surface, the substrate has a through hole penetrating the substrate in the thickness direction, and the first surface of the substrate is provided with a functional component, wherein: the heat dissipation structure includes a heat dissipation portion, a heat extraction portion and a thermal connection portion, the heat extraction portion is arranged on the side where the first surface is located, the heat dissipation portion includes a second heat dissipation portion arranged on the side where the second surface of the substrate is located, and the thermal connection portion passes through the substrate via the through hole; and the heat extraction portion is suitable for conducting heat from the functional component to the second heat dissipation portion via the thermal connection portion.

[0125] The heat dissipation portion may further include a first heat dissipation portion, which is disposed on the side where the first surface is located and is directly thermally connected to the heat extraction portion.

[0126] The semiconductor device may be a bulk acoustic wave resonator, the heat extraction portion being adapted to conduct heat away from an active acoustic region of the resonator.

[0127] The heat dissipation portion may form a dissipation structure for heat transfer.

[0128] An embodiment of the present invention further relates to a filter, comprising the above-mentioned BAW resonator or the above-mentioned heat dissipation structure. Optionally, the filter comprises a plurality of the above-mentioned BAW resonators; the thermal connection part is provided in the gap between at least some adjacent resonators, or at least some adjacent resonators share the thermal connection part.

[0129] The embodiment of the present invention also relates to an electronic device, including the above-mentioned filter. It should be noted that the electronic device here includes but is not limited to intermediate products such as RF front-ends and filter amplifier modules, as well as terminal products such as mobile phones, WIFI, and drones.

[0130] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A bulk acoustic wave resonator, comprising: A substrate having a first surface, a second surface and a through hole penetrating the substrate; Acoustic mirror; A bottom electrode disposed above the substrate; a top electrode, opposite to the bottom electrode; a piezoelectric layer disposed above the bottom electrode and between the bottom electrode and the top electrode; and Heat dissipation structure, in: The area where the acoustic mirror, the bottom electrode, the piezoelectric layer and the top electrode overlap in the thickness direction of the substrate is the effective area of ​​the resonator, and the bottom electrode, the piezoelectric layer and the top electrode are arranged on the first surface of the substrate; The heat dissipation structure comprises a heat dissipation portion, a heat extraction portion, and a heat connection portion thermally connecting the heat dissipation portion and the heat extraction portion, wherein the heat extraction portion is located outside the effective area and the heat extraction portion is in thermal contact with an edge area of ​​the effective area; The heat dissipation portion includes a second heat dissipation portion arranged on a side where the second surface of the substrate is located; The thermal connection portion passes through the through hole of the substrate in the thickness direction of the substrate to conduct heat from the heat extraction portion to the second heat dissipation portion; The heat dissipation portion is formed with a dissipation structure for increasing the heat dissipation area and forming heat transfer. On the same surface of the substrate, the farther away from the center of the heat dissipation portion, the larger the contact area between the heat dissipation portion and the air, so as to effectively increase the gradient of the temperature field along the radial direction.

2. The BAW resonator according to claim 1, wherein: The heat dissipation portion further includes a first heat dissipation portion, which is disposed on the side where the first surface is located and is directly thermally connected to the heat extraction portion.

3. The BAW resonator according to claim 1 or 2, wherein: The BAW resonator further comprises a first heat-conducting insulating medium layer; The heat extraction portion is arranged on one side of the first surface of the substrate, the first thermally conductive insulating medium layer is arranged between the bottom electrode and the heat extraction portion, and the bottom electrode is located above the first thermally conductive insulating medium layer, keeps contact with the first thermally conductive insulating medium layer and is spaced apart from the heat extraction portion.

4. The BAW resonator according to claim 3, wherein: The first thermally conductive insulating medium layer is made of aluminum nitride, beryllium oxide or silicone grease.

5. The BAW resonator according to claim 1 or 2, wherein: The heat extraction portion is an insulating portion; The heat extraction portion is disposed on one side of the first surface of the substrate, and the bottom electrode is located above the heat extraction portion and keeps contact with the heat extraction portion.

6. The BAW resonator according to claim 1 or 2, wherein: The heat extraction portion extends to the upper surface of the piezoelectric layer and keeps contact with the piezoelectric layer while being spaced apart from the top electrode.

7. The BAW resonator according to claim 1 or 2, wherein: The BAW resonator further includes a heat-conducting second thermally conductive insulating medium layer; The heat extraction portion extends along the upper surface of the piezoelectric layer to below the second heat-conducting insulating medium layer and keeps contact with the second heat-conducting insulating medium layer; The top electrode is located above the second thermally conductive insulating medium layer, keeps contact with the second thermally conductive insulating medium layer and is spaced apart from the heat extraction portion.

8. The BAW resonator according to claim 7, wherein: The second thermally conductive insulating medium layer is made of aluminum nitride, beryllium oxide or silicone grease.

9. The BAW resonator according to claim 1 or 2, wherein: The heat extraction portion is an insulating portion; The heat extraction portion extends along the upper surface of the piezoelectric layer to below the top electrode, and the top electrode is located above the heat extraction portion and keeps contact with the heat extraction portion.

10. The BAW resonator according to claim 2, wherein: The first heat dissipation portion is at least partially disposed around the effective area.

11. The BAW resonator of claim 10, wherein: The first heat dissipation portion and / or the second heat dissipation portion includes a portion in contact with air to exchange heat with the air and / or a portion provided in the substrate and in contact with the substrate to exchange heat with the substrate.

12. The BAW resonator according to claim 1 or 2, wherein: Through Holes Round through holes with diameters ranging from 1-30 μm.

13. The BAW resonator of claim 12, wherein: The diameter of the through hole is 5-20 μm.

14. The BAW resonator according to claim 1 or 2, wherein: The through hole is a rectangular through hole. In the cross section of the rectangular through hole, the length of the rectangle ranges from 20 to 80 μm and the width ranges from 2 to 20 μm.

15. The BAW resonator of claim 14, wherein: In the cross section of the rectangular through-hole, the length of the rectangle ranges from 40 to 60 μm, and the width ranges from 5 to 10 μm.

16. The BAW resonator of claim 2, wherein: The first heat dissipation portion and / or the second heat dissipation portion includes a plurality of strip-shaped protrusions.

17. The BAW resonator of claim 16, wherein: The band-shaped protrusions are distributed at equal intervals, and each band-shaped protrusion has the same width, which ranges from 0.5 to 4 μm; the interval between two adjacent band-shaped protrusions ranges from 0.5 to 6 μm; and the height of the band-shaped protrusions ranges from 0.5 to 20 μm.

18. The BAW resonator of claim 2, wherein: The first heat dissipation portion and / or the second heat dissipation portion includes a plurality of columnar protrusions.

19. The BAW resonator of claim 18, wherein: The columnar protrusions are regular hexagonal prism protrusions; The columnar protrusions are distributed at equal intervals, and the side lengths of each regular hexagonal prism structure are the same, ranging from 0.5 to 4 μm; the regular hexagonal prism structures are distributed at equal intervals, and the distance between two adjacent regular hexagonal prisms is 0.5 to 6 μm; the height of the regular hexagonal prism protrusions ranges from 0.5 to 20 μm.

20. The BAW resonator of claim 19, wherein: The columnar protrusions are cylindrical protrusions, and the multiple columnar protrusions are distributed in concentric circles; The radius of the columnar protrusions gradually decreases in the radial outward direction, and the number of columnar protrusions in each circle formed by the columnar protrusions gradually increases; the radii of the columnar protrusions of two adjacent circles satisfy the geometric ratio law, and the ratio of the radius of the columnar protrusions of the inner circle to the radius of the columnar protrusions of the outer circle is α1; the number of columnar protrusions of two adjacent circles satisfies the geometric ratio law, and the ratio of the number of columnar protrusions of the outer circle to the number of columnar protrusions of the inner circle is α2, and α2 / α1 is greater than 1, Wherein: the maximum value of the radius of the columnar protrusions ranges from 4 to 30 μm, and the minimum value of the number of columnar protrusions in a circle ranges from 8 to 16.

21. The BAW resonator of claim 2, wherein: The first heat dissipation portion and / or the second heat dissipation portion includes a plurality of annular protrusions in a concentric circle structure.

22. The BAW resonator of claim 21, wherein: The width of the annular protrusion and the spacing between adjacent annular protrusions satisfy: (1) The radius of the annular protrusion gradually narrows outward; (2) The spacing between two adjacent annular protrusions satisfies the geometric ratio rule, and the width ratio of the outer annular protrusion to the inner annular protrusion is greater than 0 and less than 1; or, the spacing between two adjacent annular protrusions satisfies the arithmetic difference rule, and the width difference between the outer annular protrusion and the inner annular protrusion is b, and the range of b is 0.1-0.5 μm, Wherein: the maximum value of the width of the annular protrusions ranges from 2 to 20 μm, and the maximum value of the interval between the annular protrusions ranges from 4 to 40 μm.

23. The BAW resonator according to claim 1 or 2, wherein: The distance between the heat extraction portion and the effective area in the lateral direction is not less than 10 sound wave wavelengths.

24. The BAW resonator according to claim 1 or 2, wherein: The second heat dissipation portion covers the second surface of the substrate; All thermal connections are connected to the second heat sink.

25. A heat dissipation structure of a semiconductor device, the semiconductor device comprising a substrate, the substrate comprising a first surface and a second surface, the substrate comprising a through hole penetrating the substrate in a thickness direction, the first surface of the substrate being provided with a functional component, wherein: The heat dissipation structure comprises a heat dissipation portion, a heat extraction portion and a heat connection portion, wherein the heat extraction portion is arranged on the side where the first surface is located, the heat dissipation portion comprises a second heat dissipation portion arranged on the side where the second surface of the substrate is located, and the heat connection portion passes through the substrate via the through hole; and The heat extraction portion is suitable for conducting heat from the functional component to the second heat dissipation portion via the thermal connection portion. The heat dissipation portion is formed with a dissipation structure for increasing the heat dissipation area and forming heat transfer. On the same surface of the substrate, the farther the position is from the center of the heat dissipation portion, the larger the contact area between the heat dissipation portion and the air, so as to effectively increase the gradient of the temperature field along the radial direction.

26. The heat dissipation structure according to claim 25, wherein: The heat dissipation portion further includes a first heat dissipation portion, which is disposed on the side where the first surface is located and is directly thermally connected to the heat extraction portion.

27. The heat dissipation structure according to claim 25 or 26, wherein: Through Holes Round through holes with diameters ranging from 1-30 μm.

28. The heat dissipation structure according to claim 27, wherein: The diameter of the through hole is 5-20 μm.

29. The heat dissipation structure according to claim 25 or 26, wherein: The through hole is a rectangular through hole. In the cross section of the rectangular through hole, the length of the rectangle ranges from 20 to 80 μm and the width ranges from 2 to 20 μm.

30. The heat dissipation structure according to claim 29, wherein: In the cross section of the rectangular through-hole, the length of the rectangle ranges from 40 to 60 μm, and the width ranges from 5 to 10 μm.

31. The heat dissipation structure according to claim 25 or 26, wherein: The semiconductor device is a bulk acoustic wave resonator, and the heat extraction portion is adapted to conduct heat away from an active acoustic region of the resonator.

32. A filter comprising the bulk acoustic wave resonator according to any one of claims 1-24 or the heat dissipation structure according to any one of claims 25-31.

33. A filter according to claim 32, wherein: The filter comprises a plurality of bulk acoustic wave resonators according to any one of claims 1 to 24; The thermal connection part is arranged at the gap between at least some adjacent resonators, or at least some adjacent resonators share the thermal connection part.

34. An electronic device comprising the filter according to claim 32 or 33.

Images