CN111193490A

CN111193490A - Heat-dissipating structures, BAW resonators with heat-dissipating structures, filters and electronic equipment

Info

Publication number: CN111193490A
Application number: CN201811355751.XA
Authority: CN
Inventors: 孙晨; 庞慰; 张孟伦; 杨清瑞
Original assignee: Tianjin University; ROFS Microsystem Tianjin Co Ltd
Current assignee: Tianjin University; ROFS Microsystem Tianjin Co Ltd
Priority date: 2018-11-14
Filing date: 2018-11-14
Publication date: 2020-05-22
Also published as: WO2020098488A1

Abstract

The invention relates to a bulk acoustic wave resonator, comprising: a 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 the bottom electrode and the top electrode between electrodes; 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 an effective area of the resonator; the heat dissipation structure includes a heat dissipation part and a heat dissipation part connected to the heat dissipation part. a heat extraction part, the heat extraction part is located outside the effective area, the heat extraction part is in thermal contact with the edge area of the effective area and is suitable for conducting heat from the effective area to the heat dissipation part. The present invention also relates to a filter having the above-mentioned resonator, an electronic device having the filter, and a heat dissipation structure of a semiconductor device.

Description

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

Technical Field

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, an electronic apparatus having the filter, and a heat dissipation structure for a semiconductor device.

Background

A film bulk wave resonator made by using longitudinal resonance of a piezoelectric film in the thickness direction has become a viable alternative to surface acoustic wave devices and quartz crystal resonators in the fields of mechanical communication and high-speed serial data applications. The RF front-end bulk wave filter/duplexer provides superior filtering characteristics, such as low insertion loss, steep transition band, large power capability, and strong anti-electrostatic discharge (ESD) capability. The high-frequency film bulk wave oscillator with ultralow frequency temperature drift has the advantages of low phase noise, low power consumption and wide bandwidth modulation range. In addition, these micro thin-film resonators use CMOS compatible processes on silicon substrates, which can reduce unit cost and facilitate eventual integration with CMOS circuitry.

Bulk wave resonators comprise an acoustic mirror and two electrodes, and a layer of piezoelectric material, called piezoelectric excitation, located between the electrodes. Also called bottom and top electrodes are excitation electrodes, whose function is to cause mechanical oscillations of the layers of the resonator. The acoustic mirror forms an acoustic isolation between the bulk wave resonator and the substrate to prevent the acoustic waves from propagating out of the resonator, causing energy loss.

Theoretically, the bulk acoustic wave resonator has only the mutual conversion of mechanical energy and electrical energy in an operating state, but in a practical situation, the electrical energy and the acoustic wave in the bulk acoustic wave resonator are always inevitably partially converted into thermal energy, and the heating effect becomes more remarkable as the frequency of the resonator is higher. Since the thickness of the key components of the bulk acoustic wave resonator, i.e. the piezoelectric film and the electrodes, is only in the order of micrometers or nanometers, the accumulation of heat therein can bring about significant negative effects, such as causing the temperature of the resonator to rise to cause the frequency of the resonator to drift, or causing stress to build up and cause the piezoelectric stack to deform, thereby affecting the reliability and lifetime of the resonator, while limiting further increases in the power capacity of the resonator.

Disclosure of Invention

The method for effectively reducing the influence of heating on the resonator is realized by constructing the heat dissipation structure and transferring heat to the outside of the resonance structure through the heat dissipation structure in time, and the resonator can have higher reliability and higher power capacity by constructing the heat dissipation structure.

The present invention is directed to alleviating or solving at least one aspect of the heat dissipation problem of the prior art resonators.

According to an aspect of an embodiment of the present invention, there is provided a bulk acoustic wave resonator including: a substrate; an acoustic mirror; a bottom electrode disposed over the substrate; a top electrode opposing the bottom electrode; a piezoelectric layer disposed above the bottom electrode and between the bottom electrode and the top electrode; and a heat dissipation structure, wherein: the overlapped area of the acoustic mirror, the bottom electrode, the piezoelectric layer and the top electrode in the thickness direction of the substrate is an effective area of the resonator; the heat dissipation structure comprises a heat dissipation part and a heat extraction part connected with the heat dissipation part, the heat extraction part is positioned outside the effective area, and the heat extraction part is in thermal contact with the edge area of the effective area and is suitable for conducting heat from the effective area to the heat dissipation part.

Optionally, the bulk acoustic wave resonator further includes a first heat-conducting insulating medium layer for conducting heat; the heat extraction part is arranged on the substrate, the first heat conduction insulating medium layer is arranged between the bottom electrode and the heat extraction part, and the bottom electrode is positioned above the first heat conduction insulating medium layer, keeps contact with the first heat conduction insulating medium layer and is spaced from the heat extraction part. Further, the first heat-conducting insulating medium layer is made of aluminum nitride, beryllium oxide or silicone grease.

Optionally, the heat extraction part is an insulation part; the heat extraction part is arranged on the substrate, and the bottom electrode is positioned above the heat extraction part and keeps contact with the heat extraction part.

Optionally, the heat extraction portion extends to an upper surface of the piezoelectric layer and is in contact with the piezoelectric layer while being spaced apart from the top electrode.

Optionally, the bulk acoustic wave resonator further includes a second heat-conducting insulating medium layer; the heat leading-out part extends to the position below the second heat conduction insulating medium layer along the upper surface of the piezoelectric layer and is in contact with the second heat conduction insulating medium layer; the top electrode is positioned above the second heat-conducting insulating medium layer, is in contact with the second heat-conducting insulating medium layer and is spaced apart from the heat extraction portion. Further, the second heat-conducting insulating medium layer is made of aluminum nitride or silicone grease.

Optionally, the heat extraction part is an insulation part; the thermal lead-out extends along the piezoelectric layer upper surface to below a top electrode located above and in contact with the thermal lead-out.

Optionally, the heat dissipation portion is at least partially disposed around the active area. Further, the heat dissipation portion includes a portion that is in contact with air to exchange heat with the air and/or a portion that is provided in the substrate in contact with the substrate to exchange heat with the substrate.

Optionally, the heat dissipation portion includes a plurality of band-shaped protrusions. Furthermore, the banded bulges are distributed at equal intervals, the width of each banded bulge is the same, and the width range is 0.5-4 μm; the distance range of two adjacent strip-shaped bulges is 0.5-6 mu m; the height of the band-shaped protrusions ranges from 0.5 to 20 μm.

Optionally, the heat dissipation portion includes a plurality of stud bumps. Further, the columnar protrusions are regular hexagonal prism protrusions; the columnar bulges are distributed at equal intervals, the side length of each regular hexagonal prism structure is the same, and the range of the side length is 0.5-4 mu m; the regular hexagonal prism structures are distributed at equal intervals, and the interval between every two adjacent regular hexagonal prisms is 0.5-6 mu m; the height of the regular hexagonal prism protrusions ranges from 0.5 to 20 μm.

The cylindrical protrusions are distributed in a concentric circle shape, the radius of each cylindrical protrusion is gradually reduced in the radial outward direction, the number of the cylindrical protrusions in each circle formed by the cylindrical protrusions is gradually increased, the radius of the cylindrical protrusions of two adjacent circles meets the equal ratio law, the ratio of the radius of the cylindrical protrusion of the inner circle to the radius of the cylindrical protrusion of the outer circle is α 1, the number of the cylindrical protrusions of two adjacent circles meets the equal ratio law, the ratio of the number of the cylindrical protrusions of the outer circle to the number of the cylindrical protrusions of the inner circle is α 2, α 2/α 1 is larger than 1, the maximum radius range of the cylindrical protrusions is 4-30 mu m, and the minimum number range of the cylindrical protrusions in one circle is 8-16.

Optionally, the heat dissipation portion includes a plurality of annular protrusions of a concentric circular structure.

Optionally, the plurality of annular protrusions form a dissipative structure for heat transfer. Further, the width of the annular protrusion and the distance between adjacent annular protrusions satisfy: (1) the radius of the annular bulge is gradually narrowed outwards; (2) the distance between two adjacent annular bulges meets the equal ratio rule, and the width ratio of the outer annular bulge to the inner annular bulge is more than 0 and less than 1; or the distance between two adjacent annular bulges meets the equal difference law, the width difference between the outer annular bulge and the inner annular bulge is b, and the range of b is 0.1-0.5 mu m, wherein: the maximum value of the width of the annular protrusions ranges from 2 to 20 μm, and the maximum value of the pitch of the annular protrusions ranges from 4 to 40 μm.

Optionally, in the bulk acoustic wave resonator, a distance between the heat extraction portion and the active region in the lateral direction is not less than 10 acoustic wave wavelengths.

Embodiments of the present invention also relate to a heat dissipation structure of a semiconductor device having a substrate with a first surface provided with a functional part, wherein: the heat dissipation structure comprises a heat dissipation part and a heat leading-out part; and the heat extraction portion is adapted to conduct heat from the functional component to the heat dissipation portion. Optionally, the semiconductor device is a bulk acoustic wave resonator, and the heat extraction portion is adapted to conduct heat from an active acoustic region of the resonator.

Embodiments of the present invention also relate to a filter including the bulk acoustic wave resonator or the heat dissipation structure.

Embodiments of the present invention also relate to an electronic device including the filter described above.

Drawings

These and other features and advantages of the various embodiments of the disclosed invention will be better understood from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate like parts throughout, and in which:

fig. 1A and 1B are a schematic top view and a cross-sectional view a-a of a resonator having a heat dissipation structure according to an exemplary embodiment of the present invention, respectively, and an MT area is shown in fig. 1B;

fig. 2 is a schematic cross-sectional view of a resonator having a heat dissipation structure according to an exemplary embodiment of the present invention, showing an MT area;

fig. 3 is a schematic cross-sectional view of a resonator having a heat dissipation structure according to another exemplary embodiment of the present invention, showing an MT area;

fig. 4 is a schematic cross-sectional view of a resonator having a heat dissipation structure according to still another exemplary embodiment of the present invention, showing an MT area;

fig. 5A and 5B are a schematic top view and a partially enlarged view of an MA area, respectively, of a resonator having a heat dissipation structure according to an exemplary embodiment of the present invention;

fig. 6A and 6B are a schematic top view and a partially enlarged view of an MA area, respectively, of a resonator having a heat dissipation structure according to an exemplary embodiment of the present invention;

fig. 7A and 7B are a schematic top view and a partially enlarged view of an MA area, respectively, of a resonator having a heat dissipation structure according to an exemplary embodiment of the present invention;

fig. 8A and 8B are a schematic top view and a partially enlarged view of an MA area, respectively, of a resonator having a heat dissipation structure according to an exemplary embodiment of the present invention;

fig. 9 is a schematic cross-sectional view of a resonator having a heat dissipation structure according to an exemplary embodiment of the present invention, illustrating an MS region.

Detailed Description

The technical scheme of the invention is further specifically described by the following embodiments and the accompanying drawings. In the specification, the same or similar reference numerals denote 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 general inventive concept of the present invention and should not be construed as limiting the invention.

The heat transmission efficiency of the heat dissipation structure can be greatly improved by constructing the contact interface of the heat dissipation structure and the acoustic part (namely the effective area) AR of the resonator, and constructing the microstructure (further, the dissipation structure) capable of increasing the heat dissipation area on the interface of the heat dissipation part (such as a metal layer) of the heat dissipation structure and the air and the interface of the heat dissipation part and the substrate.

A bulk acoustic wave resonator according to an embodiment of the present invention is described below with reference to fig. 1 to 9.

The general structure of the bulk acoustic wave resonator is exemplarily described below with reference to fig. 1A and 1B. Fig. 1A and 1B are a schematic top view and a cross-sectional view a-a of a resonator having a heat dissipation structure according to an exemplary embodiment of the present invention, respectively, and an MT area is shown in fig. 1B. As shown in fig. 1A and 1B, the resonator generally includes a resonator portion and a heat dissipation structure portion. The resonator comprises the following components: 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 the materials that may be used for substrate 100 are, but not limited to: single crystal silicon (Si), gallium arsenide (GaAs); sapphire, etc., and the

electrodes

102 and 104 may be selected from materials including, but 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 equivalent structures capable of realizing acoustic isolation effect, wherein the bragg reflection layer structure is formed by periodically and alternately forming low-acoustic-resistance and high-acoustic-resistance materials, and the low-acoustic-resistance materials include but are not limited to: silicon dioxide (SiO2), molybdenum (Mo), etc., high acoustic resistance materials including, but 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), and the like. The effective acoustic area AR of the resonator is defined by the overlapping portions in the lateral direction 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.

The heat dissipation structure comprises the following components: a heat-conducting medium layer 105 and a heat-conducting metal layer 106. The material of the dielectric layer 105 may be selected from, but not limited to: aluminum nitride (AlN), beryllium oxide (BeO), silicone grease, and the like. The material used for the dielectric layer should be perceived as having good thermal conductivity and insulating; materials of the metal layer 106 include, but are not limited to: copper (Cu), aluminum (Al), molybdenum (Mo), gold (Au), and the like.

In an alternative embodiment, the inner edge of the metal layer 106 is located outside the effective acoustic area AR and at a distance from the boundary of the acoustic area, which is not less than 10 acoustic wavelengths.

It should be noted that the heat conducting metal layer of the heat dissipation structure may also be replaced by a non-metal heat conducting material, and in addition, the heat dissipation structure may not be provided with a heat conducting medium layer under the condition that the heat dissipation structure is made of a non-conducting heat conducting material.

As shown in the drawing, the heat dissipation structure has a heat extraction portion in contact with the peripheral portion of the effective area AR and a heat dissipation portion in contact with the heat extraction portion. The heat extraction portion may be considered to be a portion of the heat dissipation structure in the region where the MT is indicated.

As shown in fig. 1B, the bulk acoustic wave resonator with a heat dissipation structure has 3 critical contact areas, namely a contact area MT where the heat dissipation structure contacts the peripheral part or edge area of the acoustic part (active area) of the resonator, a heat dissipation structure-to-substrate contact area MS, and a heat dissipation structure-to-air contact area MA.

Based on the above, an embodiment of the present invention provides a bulk acoustic wave resonator, including: a substrate; an acoustic mirror; a bottom electrode disposed over the substrate; a top electrode opposing the bottom electrode; a piezoelectric layer disposed above the bottom electrode and between the bottom electrode and the top electrode; and a heat dissipation structure, wherein: the overlapped area of the acoustic mirror, the bottom electrode, the piezoelectric layer and the top electrode in the thickness direction of the substrate is an effective area of the resonator; the heat dissipation structure comprises a heat dissipation part and a heat extraction part connected with the heat dissipation part, the heat extraction part is positioned outside the effective area, and the heat extraction part is in thermal contact with the edge area of the effective area and is suitable for conducting heat from the effective area to the heat dissipation part.

Fig. 2 is a schematic cross-sectional view of a resonator having a heat dissipation structure according to an exemplary embodiment of the present invention, showing an MT area.

As shown in fig. 2, the overall structure of the resonator example with the heat dissipation structure is: the upper surface of the substrate 200 has an acoustic mirror 201 (specifically exemplified by a cavity structure) and a metal layer structure 206. The cavity or acoustic mirror 201 extends through the metal layer 206 and is partially embedded in the substrate 200. Over the cavity is an insulating dielectric layer 205 that spans laterally the entire cavity and extends to the upper surface of the metal layer 206 to maintain contact therewith. The bottom electrode 202 is located over the insulating dielectric layer 205 and is in contact with the insulating dielectric layer 205. In the lateral direction, the bottom electrode 202 spans the entire cavity or acoustic mirror 201, but the bottom electrode 202 as a whole falls within the range of the insulating dielectric layer 205. The piezoelectric film 203 is located above the bottom electrode and is in contact with the upper surface of the bottom electrode. Further, the piezoelectric film 203 extends laterally beyond the bottom electrode 202 and is in 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 positioned above the piezoelectric film 203 and is in contact with the upper surface of the film 203. While the top electrode 204 falls laterally within the cavity 201.

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 an effective piezoelectric effect area (effective area) AR of the resonator. The lower surface of the metal layer 206 is held in contact with the substrate and extends laterally beyond the range of the piezoelectric film 203, and the metal layer 206 falls completely outside the area AR.

Based on the above, the bulk acoustic wave resonator according to the embodiment of the present invention may further include a first heat-conducting insulating medium layer that conducts heat; the heat extraction part is arranged on the substrate, the first heat conduction insulating medium layer is arranged between the bottom electrode and the heat extraction part, and the bottom electrode is positioned above the first heat conduction insulating medium layer, keeps contact with the first heat conduction insulating medium layer and is spaced from the heat extraction part. The first heat conductive insulating medium layer may be made of, for example, aluminum nitride or silicone grease.

Under the condition that no insulating medium layer is arranged, the heat leading-out part is an insulating part; and the heat extraction part is arranged on the substrate, and the bottom electrode is positioned above the heat extraction part and keeps contact with the heat extraction part.

Fig. 3 is a schematic cross-sectional view of a resonator having a heat dissipation structure according to another exemplary embodiment of the present invention, showing an MT area.

As shown in fig. 3, the overall structure of the resonator example with the heat dissipation structure is: the substrate 300 has an acoustic mirror 301 (illustratively a cavity structure) on its upper surface, the cavity or acoustic mirror 301 being embedded in the substrate 300. Above the cavity there is a bottom electrode 302, which bottom electrode 302 spans the entire cavity or acoustic mirror 301 and is partly 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. Further, the piezoelectric film 303 extends laterally beyond the range of the bottom electrode 302 and partially contacts the substrate 300. The top electrode 304 is located above the piezoelectric film 303 and is held in contact with the upper surface of the piezoelectric film 303. At the same time, the top electrode 204 falls laterally within the cavity or acoustic mirror 301.

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

Part of the lower surface of the metal layer 306 is held in contact with the substrate and extends laterally beyond the range of the piezoelectric film 303, while the other part of the lower surface of the metal layer 306 rises up along the outer inclined surface of the piezoelectric film 303 and covers the entire outer inclined surface of the piezoelectric film 303 and a part of the upper horizontal surface thereof, and the metal layer 306 falls completely outside the area AR.

Based on the above, in the bulk acoustic wave resonator according to the embodiment of the present invention, the heat extraction portion extends to the upper surface of the piezoelectric layer and is held in contact with the piezoelectric layer while being spaced apart from the top electrode.

Fig. 4 is a schematic cross-sectional view of a resonator having a heat dissipation structure according to still another exemplary embodiment of the present invention, showing an MT area.

As shown in fig. 4, the overall structure of the resonator example with the heat dissipation structure is: the substrate 400 has an acoustic mirror 401 (illustratively a cavity structure) on its upper surface, with the acoustic mirror or cavity 401 embedded in the substrate 400. Above the cavity is a bottom electrode 402, which bottom electrode 402 spans the entire acoustic mirror or cavity 401 and is partially in contact with the substrate 400. The piezoelectric film 403 is positioned over the bottom electrode and is in contact with the top surface of the bottom electrode. Further, the piezoelectric film 403 extends laterally beyond the bottom electrode 402 and partially contacts the substrate 400.

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 an effective piezoelectric effect area (effective area) AR of the resonator.

Part of the lower surface of the metal layer 406 is held in contact with the substrate and extends beyond the range of the piezoelectric film 403 in the lateral direction, while the other part of the lower surface of the metal layer 406 rises up along the outer inclined surface of the piezoelectric film 403 and covers the entire outer inclined surface of the piezoelectric film 403 and a part of the upper horizontal surface thereof, and the metal layer 406 falls completely outside the area AR.

The upper surface of the metal layer 406 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 area AR.

The top electrode 404 is located above the piezoelectric film 403 and partially held in contact with the upper surface of the piezoelectric film 403. While the portion of the top electrode 404 in contact with the piezoelectric film 403 laterally falls within the acoustic mirror or cavity 401. Another portion of the bottom surface of the top electrode is in contact with the insulating dielectric layer 405.

Based on the above, the bulk acoustic wave resonator according to the embodiment of the present invention may further include a second heat-conducting insulating medium layer that conducts heat; the heat leading-out part extends to the position below the second heat conduction insulating medium layer along the upper surface of the piezoelectric layer and is in contact with the second heat conduction insulating medium layer; the top electrode is positioned above the second heat-conducting insulating medium layer, is in 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.

Under the condition that no insulating medium layer is arranged, the heat leading-out part is an insulating part; and the thermal lead-out extends along the piezoelectric layer upper surface to below a top electrode located above and in contact with the thermal lead-out.

The contact area MA of the heat dissipation structure with air is described below by way of example with reference to fig. 5A-8B.

Fig. 5A and 5B are a schematic top view and a partially enlarged view of an MA area, respectively, of a resonator having a heat dissipation structure according to an exemplary embodiment of the present invention.

As shown in FIG. 5A, the area of metal layer 506 is circular with a radius R500, and R500 ranges from 40 to 200 μm. Furthermore, the area of metal layer 506 may also be other geometric shapes that may enclose the acoustic portion (active area) of the resonator therein. The surface of the metal layer 506 in the MA region that is in contact with air contains a plurality of stripe-like raised structures, each having two side surfaces that are effectively increased surface area.

An enlarged view of the local zone Z501 in fig. 5A is shown in fig. 5B: the banded convex structures are distributed at equal intervals, the width of each banded convex structure is the same and is D501, and the range of the D501 is 0.5-4 mu m. The banded convex structures are distributed at equal intervals, the interval between two adjacent convex structures is D502, and the range of D502 is 0.5-6 μm. The height of the stripe-shaped projection is H501, and the range of H501 is 0.5-20 μm.

Fig. 6A and 6B are a schematic top view and a partially enlarged view of an MA area, respectively, of a resonator having a heat dissipation structure according to another exemplary embodiment of the present invention.

As shown in FIG. 6A, the area of the metal layer 606 is circular with a radius R600, and the range of R600 is 40-200 μm. In addition, the area of the metal layer 606 may also be other geometric shapes that may enclose the acoustic portion (active area) of the resonator therein. The surface of metal layer 606 in the MA region that is in contact with air contains a plurality of columnar raised structures, the side surfaces of each raised structure being effectively increased surface area. The cylindrical structure is a regular hexagonal prism in this embodiment, but other shapes such as a cylinder, a diamond-shaped column, a rectangular column, a triangular prism or other polygonal prisms may be used.

An enlarged view of the local zone Z601 in fig. 6A is shown in fig. 6B: the side length of each regular hexagonal prism structure is the same and is D601, and the range of the D601 is 0.5-4 μm. The regular hexagonal prism structures are distributed at equal intervals, the interval between every two adjacent regular hexagonal prisms is D602, and the range of D602 is 0.5-6 mu m. The height of the regular hexagonal prism protrusions is H601, and the range of H601 is 0.5-20 μm.

Fig. 7A and 7B are a schematic top view and a partially enlarged view of an MA area, respectively, of a resonator having a heat dissipation structure according to still another exemplary embodiment of the present invention.

As shown in FIG. 7A, the area of the metal layer 706 is circular with a radius R700, and R700 ranges from 40-200 μm. In addition, the area of the metal layer 706 may be other geometric shapes that may enclose the acoustic portion (active area) of the resonator therein. The surface of the metal layer 706 in contact with air in the MA region contains concentric annular raised structures, the side surfaces of each annular raised structure being effectively increased surface area.

An enlarged view of the local zone Z701 in fig. 7A is shown in fig. 7B: the width of the circular ring is D701, and the interval width or the distance between two adjacent circular rings is D702. The height of the circular ring bulge is H701, and the range of the H701 is 0.5-20 mu m.

In a further embodiment, the distribution of the width D701 of the rings and the spacing D702 of the rings satisfies:

(1) gradually narrowing outwards along the radius of the circular ring;

(2) the distance between two adjacent rings satisfies the geometric rule, the width ratio of the outer ring to the inner ring is a (0< a <1), or the distance between two adjacent rings satisfies the geometric rule, the width difference between the outer ring and the inner ring is b, and the range of b is 0.1-0.5 μm;

wherein the maximum value range of the width D701 of the circular rings is 2-20 μm, and the maximum value range of the distance D702 of the circular rings is 4-40 μm.

The annular convex structures distributed according to the rule can form a dissipation structure, namely, the farther the position is away from the center of the circle, the larger the contact area of the metal layer 706 and the air is, the faster the heat dissipation speed is, so that the gradient of the temperature field along the radial direction can be effectively increased, and the heat in the resonator can be transmitted to the outside more quickly.

Fig. 8A and 8B are a schematic top view and a partially enlarged view of an MA area, respectively, of a resonator having a heat dissipation structure according to still another exemplary embodiment of the present invention.

As shown in FIG. 8A, in the 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 area of the metal layer 806 may be other geometric shapes that may enclose the acoustic portion (active area) of the resonator therein. The surface of the metal layer 806 in contact with air in the MA region may comprise a dissipative cylindrical array of structures, the side surfaces of each cylindrical raised structure being effectively increased surface area.

An enlarged view of the partial region Z801 in fig. 8A is shown in fig. 8B: the height of the cylindrical projection is H801, and the range of H801 is 0.5-20 μm. The distance between the centers of two adjacent circles of cylindrical protrusions is D801, and the range of D801 is 10-20 mu m.

Further, the radius of the cylinder is R801, and the number N of cylinders in each circle satisfies:

(1) r801 is gradually reduced outwards along the radius R800 direction of the metal layer, and N is gradually increased outwards along the direction;

(2) the cylindrical radii of two adjacent circles meet the equal ratio rule, and the ratio of the cylindrical radius of the inner circle to the cylindrical radius of the outer circle is α 1;

(3) the number of the cylinders of two adjacent circles meets the equal ratio rule, the ratio of the number of the cylinders of the outer circle to the number of the cylinders of the inner circle is α 2, and α 2/α 1 is ensured to be larger than 1;

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

Since α 2/α 1 is greater than 1, the ultimate effect is that the farther the position from the center of the metal layer 806, the larger the contact area with air, and similar to the example in fig. 7A and 7B, the dissipation structure with improved heat dissipation efficiency is formed in the embodiment of fig. 8A and 8B, and the ring structure provides stronger dissipation effect than the cylindrical protrusion structure, so that the heat dissipation efficiency of the embodiment of fig. 8A and 8B is theoretically better than that of the example in fig. 7A and 7B.

The contact area MS of the heat dissipation structure with the substrate is exemplarily described below with reference to fig. 9.

Fig. 9 illustrates an exemplary combination of the heat dissipating portion 906 of the heat dissipating structure and the substrate 900.

As will be appreciated by those skilled in the art, the top surface structure of the heat sink or metal layer in the example of fig. 5A-8B may also be applied to the MS region, i.e., to the contact interface of the heat sink or metal layer with the substrate.

In the present invention, the electrode constituent material may be gold (Au), tungsten (W), molybdenum (Mo), platinum (Pt), ruthenium (Ru), iridium (Ir), titanium Tungsten (TiW), aluminum (Al), titanium (Ti), or the like. In the present invention, the piezoelectric layer material may be aluminum nitride (AlN), zinc oxide (ZnO), lead zirconate titanate (PZT), lithium niobate (LiNbO3), Quartz (Quartz), potassium niobate (KNbO3), lithium tantalate (LiTaO3), or the like.

Based on the above, embodiments of the present invention also relate to a heat dissipation structure of a semiconductor device having a substrate with a first surface provided with a functional component, wherein: the heat dissipation structure comprises a heat dissipation part and a heat leading-out part; and the heat extraction portion is adapted to conduct heat from the functional component to the heat dissipation portion. Optionally, the semiconductor device is a bulk acoustic wave resonator, and the heat extraction portion is adapted to conduct heat from an active acoustic region of the resonator.

Embodiments of the present invention also relate to a filter including the bulk acoustic wave resonator or the package structure described above.

Embodiments of the present invention also relate to an electronic device comprising a filter as described above. It should be noted that the electronic device herein includes, but is not limited to, intermediate products such as a radio frequency front end and a filtering and amplifying module, and terminal products such as a mobile phone, WIFI, and an unmanned aerial vehicle.

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

Claims

1. A bulk acoustic wave resonator, comprising:

base;

acoustic mirror;

a bottom electrode, arranged above the substrate;

a top electrode, opposite to the bottom electrode;

a piezoelectric layer disposed over 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;

The heat dissipation structure includes a heat dissipation part and a heat extraction part connected to the heat dissipation part, the heat extraction part is located outside the effective area, the heat extraction part is in thermal contact with the edge area of the effective area and is suitable for dissipating heat The portion conducts heat from the active area.

2. The bulk acoustic wave resonator of claim 1, wherein:

The bulk acoustic wave resonator also includes a first thermally conductive insulating medium layer that conducts heat;

The heat lead-out portion is disposed on the substrate, the first thermally conductive insulating medium layer is disposed between the bottom electrode and the heat lead-out portion, and the bottom electrode is located above the first thermally conductive insulating medium layer, and The first thermally conductive insulating medium layer is kept in contact and spaced apart from the heat extraction portion.

3. The bulk acoustic wave resonator of claim 2, wherein:

The first thermally conductive insulating medium layer is made of aluminum nitride, beryllium oxide or silicone grease.

4. The bulk acoustic wave resonator of claim 1, wherein:

the heat extraction part is an insulating part;

The heat lead-out portion is disposed on the substrate, and the bottom electrode is located above the heat lead-out portion and keeps in contact with the heat lead-out portion.

5. The bulk acoustic wave resonator of claim 1, wherein:

The heat extraction portion extends to the upper surface of the piezoelectric layer and is in contact with the piezoelectric layer to be spaced apart from the top electrode.

6. The bulk acoustic wave resonator of claim 1, wherein:

The bulk acoustic wave resonator further comprises a second thermally conductive insulating medium layer;

The heat lead-out portion extends along the upper surface of the piezoelectric layer to below the second thermally conductive insulating medium layer to maintain contact with the second thermally conductive insulating medium layer;

The top electrode is located above the second thermally conductive insulating medium layer, is in contact with the second thermally conductive insulating medium layer, and is spaced apart from the heat extraction portion.

7. The bulk acoustic wave resonator of claim 6, wherein:

The second thermally conductive insulating medium layer is made of aluminum nitride or silicone grease.

8. The bulk acoustic wave resonator of claim 1, wherein:

the heat extraction part is an insulating part;

The heat lead-out portion extends along the upper surface of the piezoelectric layer to below the top electrode, and the top electrode is located above the heat lead-out portion and keeps in contact with the heat lead-out portion.

9. The bulk acoustic wave resonator of any one of claims 1-8, wherein:

The heat dissipation portion is disposed at least partially around the effective area.

10. The bulk acoustic wave resonator of claim 9, wherein:

The heat dissipating portion includes a portion that is in contact with the air to exchange heat with the air and/or a portion that is provided in the base to contact the base to exchange heat with the base.

11. The bulk acoustic wave resonator of any one of claims 1-10, wherein:

The heat dissipation portion includes a plurality of belt-shaped protrusions.

12. The bulk acoustic wave resonator of claim 11, wherein:

The strip-shaped protrusions are distributed at equal intervals, the width of each strip-shaped protrusion is the same, and the width is in the range of 0.5-4 μm; the distance between two adjacent strip-shaped protrusions is in the range of 0.5-6 μm; 0.5-20μm.

13. The bulk acoustic wave resonator of any one of claims 1-10, wherein:

The heat dissipation portion includes a plurality of columnar protrusions.

14. The bulk acoustic wave resonator of claim 13, wherein:

The cylindrical protrusion is a regular hexagonal prism protrusion;

The columnar protrusions are distributed at equal intervals, and the side lengths of each regular hexagonal prism structure are the same, and the side length range is 0.5-4 μm; the regular hexagonal prism structures are distributed at equal intervals, and the spacing between two adjacent regular hexagonal prisms is 0.5-6 μm; The height range from 0.5-20μm.

15. The bulk acoustic wave resonator of claim 13, wherein:

The plurality of columnar protrusions form a dissipation structure for heat transfer.

16. The bulk acoustic wave resonator of claim 15, wherein:

The cylindrical protrusions are cylindrical protrusions, and the plurality of cylindrical protrusions are distributed in concentric circles;

The radius of the cylindrical protrusion gradually becomes smaller in the radially outward direction, and the number of cylindrical protrusions in each circle formed by the cylindrical protrusion gradually increases; The ratio is regular and the ratio of the radius of the cylindrical protrusion in the inner circle to the radius of the cylindrical protrusion in the outer circle is α1; The ratio of the number of cylindrical protrusions is α2, and α2/α1 is greater than 1,

Wherein: the maximum range of the radius of the cylindrical protrusions is 4-30 μm, and the minimum range of the number of cylindrical protrusions in a circle is 8-16.

17. The bulk acoustic wave resonator of any one of claims 1-10, wherein:

The heat dissipation portion includes a plurality of annular protrusions in concentric circle structures.

18. The bulk acoustic wave resonator of claim 17, wherein:

The plurality of annular protrusions form a dissipative structure for heat transfer.

19. The bulk acoustic wave resonator of claim 18, wherein:

The width of the annular protrusion and the spacing between adjacent annular protrusions satisfy:

(1) It gradually narrows outward along the radius of the annular protrusion;

(2) The spacing between two adjacent annular protrusions satisfies the law of equal ratio, and the ratio of the width of the outer annular protrusion to the inner annular protrusion is greater than 0 and less than 1; or, the spacing between adjacent two annular protrusions satisfies the equal ratio difference rule, and the width difference between the outer annular protrusion and the inner annular protrusion is b, and the range of b is 0.1-0.5μm,

Wherein: the maximum range of the width of the annular protrusions is 2-20 μm, and the maximum range of the spacing of the annular protrusions is 4-40 μm.

20. The bulk acoustic wave resonator of any one of claims 1-19, wherein:

The distance in the lateral direction between the heat extraction portion and the effective area is not less than 10 wavelengths of acoustic waves.

21. A heat dissipation structure for a semiconductor device, the semiconductor device having a base, the base having a first surface, the first surface of the base being provided with a functional component, wherein:

The heat dissipation structure includes a heat dissipation portion and a heat extraction portion; and

The heat extraction portion is adapted to conduct heat from the functional component to the heat dissipation portion.

22. The heat dissipation structure of claim 21, wherein:

The semiconductor device is a bulk acoustic wave resonator, and the heat extraction portion is adapted to conduct heat from the effective acoustic region of the resonator.

23. The heat dissipation structure of claim 21 or 22, wherein:

The heat dissipation portion forms a dissipation structure for heat transfer.

24. A filter comprising the bulk acoustic wave resonator according to any one of claims 1-20 or the heat dissipation structure according to any one of claims 21-23.

25. An electronic device comprising the filter of claim 24.