A thin film bulk acoustic wave resonator, a preparation method and a thin film bulk acoustic wave filter

Abstract

The present invention relates to a thin film bulk acoustic wave resonator, a preparation method, and a thin film bulk acoustic wave filter. The thin film bulk acoustic wave resonator comprises: a patterned second electrode layer, a patterned piezoelectric layer, a patterned first electrode layer, and a substrate stacked in sequence; a plurality of heat dissipation blind holes are arranged on the substrate, each heat dissipation blind hole is filled with a heat conductive heat dissipation material, and a high-resistance material is filled above the heat conductive heat dissipation material in each heat dissipation blind hole to form a total reflection structure; the patterned first electrode layer covers the openings of all the heat dissipation blind holes. The total reflection structure is prepared on the substrate, and the heat conductive heat dissipation material and the high-resistance material are filled in each heat dissipation blind hole. This allows the thin film bulk acoustic wave resonator of the present application to maintain its original high Q value while also solving the temperature impact caused by the insufficient heat dissipation capacity of traditional thin film bulk acoustic wave resonators. The structure has strong reliability, is easy to integrate, and has a simple preparation process.

Description

Technical Field

[0001] The present invention relates to the technical field of thin film bulk acoustic wave resonators, and in particular to a thin film bulk acoustic wave resonator, a preparation method and a thin film bulk acoustic wave filter. Background Art

[0002] A film bulk acoustic resonator (FBAR) is a device based on bulk acoustic wave theory that uses acoustic resonance to achieve electrical frequency selection. Its principle is to select frequency through the vertical resonance of the piezoelectric material between upper and lower thin-layer electrodes. By combining multiple film bulk acoustic resonators, a filter structure can be formed.

[0003] Among them, thin film bulk acoustic resonators are mainly divided into two forms, namely air cavity structure (i.e. FBAR resonant unit) and reflection array structure unit (i.e. SMR resonant unit type) related resonator devices are also called solid-state mounted resonator devices. Specifically:

[0004] 1) For FBRAs with air cavity structures, the most significant feature is that the cavity structure is prepared on the substrate through an etching process. Due to the large difference in acoustic impedance between air and electrode materials or piezoelectric materials, total reflection occurs when the sound wave is transmitted to the interface between the two, thereby achieving resonance.

[0005] However, it should be pointed out that since air is a poor conductor of heat, the heat generated or absorbed in the air-cavity FBRA is very likely to produce a heat concentration effect, resulting in a local temperature increase. The temperature change will directly cause the frequency of the air-cavity FBRA to shift, seriously affecting the performance of related devices and the use of the entire device. In addition, due to the special nature of the air cavity structure, the air-cavity FBRA has the hidden danger of insufficient supporting force, which to some extent affects the reliability of the device.

[0006] 2) For solid-state mounted resonator devices, the design of the Bragg reflector allows the sound wave to be continuously reflected at multiple interfaces with different acoustic impedances during transmission, and ultimately achieves total reflection through superposition, thereby achieving resonance. Compared with air cavity FBAR devices, the multi-layer structure causes sound leakage, which affects the Q value of the related devices, but the structural reliability and heat dissipation have been improved to a certain extent. It should be pointed out that the preparation of the Bragg reflector structure requires high process precision, and the theoretical value of the thickness between the reflective layers needs to be 1 / 4 wavelength. Therefore, in terms of cost and process difficulty, the SMR resonant unit is higher than the FBAR resonant unit.

[0007] In addition, the structural design of both the FBAR resonant unit and the SMR resonant unit is not conducive to high-density integration of components through three-dimensional stacking, and is not suitable for the current demand for chip miniaturization and integration.

[0008] In short, the main defects of FBAR devices with air cavity structures are: poor heat dissipation capability, susceptibility to temperature conditions causing frequency deviation, structural reliability risks and unfavorable integration; the main defects of solid-state mounted SMR devices are: complex process steps and difficult operation, high cost, lower Q value compared to air cavity FBAR devices, failure to completely solve the heat dissipation problem, and structural difficulties in stacking integration. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to address the deficiencies of the prior art and provide a thin film bulk acoustic wave resonator, a preparation method and a thin film bulk acoustic wave filter.

[0010] The technical solution of a thin film bulk acoustic resonator of the present invention is as follows:

[0011] It comprises: a patterned second electrode layer, a patterned piezoelectric layer, a patterned first electrode layer and a substrate;

[0012] The patterned second electrode layer, the patterned piezoelectric layer, the patterned first electrode layer and the substrate are stacked in sequence;

[0013] A plurality of heat dissipation blind holes are arranged on the substrate, each heat dissipation blind hole is filled with a heat conductive heat dissipation material, and a high resistance material is filled above the heat conductive heat dissipation material in each heat dissipation blind hole to form a total reflection structure, and the patterned first electrode layer is covered on the openings of all heat dissipation blind holes.

[0014] The beneficial effects of a thin film bulk acoustic resonator of the present invention are as follows:

[0015] A total reflection structure is prepared on the substrate, and thermal conductive and heat dissipation materials and high-resistance materials are filled in each heat dissipation blind hole. This allows the thin film bulk acoustic wave resonator of the present application to maintain its original high Q value while also solving the temperature influence caused by insufficient heat conduction capacity of traditional thin film bulk acoustic wave resonators. The structure has strong reliability, is conducive to integration, and has a simple preparation process.

[0016] Based on the above solution, the thin film bulk acoustic resonator of the present invention can be further improved as follows.

[0017] Furthermore, the substrate is made of Si, SiC or sapphire.

[0018] Furthermore, the thermally conductive and heat dissipating material includes at least one of graphite, graphene, graphite oxide, copper, gold, silver, aluminum, diamond and high thermal conductivity silicon.

[0019] Furthermore, the high-resistance material includes at least one of silicon dioxide and high-resistance silicon.

[0020] The technical solution of the present invention for preparing a thin film bulk acoustic resonator as described in any one of the above is as follows:

[0021] Arrange a plurality of heat dissipation blind holes on the substrate, fill each heat dissipation blind hole with heat conductive heat dissipation material, and fill the heat conductive heat dissipation material in each heat dissipation blind hole with high resistance material to form a total reflection structure;

[0022] A first electrode layer is provided on the substrate and covers the openings of all the heat dissipation blind vias, and the first electrode layer is patterned to form a patterned first electrode layer, wherein the patterned first electrode layer covers the openings of all the heat dissipation blind vias;

[0023] Disposing a piezoelectric layer on the patterned first electrode layer, and disposing a second electrode layer on the piezoelectric layer;

[0024] The second electrode layer and the piezoelectric layer are patterned to form a patterned second electrode layer and a patterned piezoelectric layer.

[0025] The beneficial effects of the method for preparing a thin film bulk acoustic resonator as described in any one of the above items of the present invention are as follows:

[0026] The preparation process is simple, and a full reflection structure is prepared on a substrate, and each heat dissipation blind hole is filled with heat-conducting and heat-dissipating materials and high-resistance materials, so that the prepared thin film bulk acoustic wave resonator can maintain the original high Q value while solving the temperature influence caused by insufficient heat conduction capacity of traditional thin film bulk acoustic wave resonators. The structure has strong reliability, is conducive to integration, and has a simple preparation process.

[0027] The technical solution of the present invention for preparing a thin film bulk acoustic resonator as described in any one of the above is as follows:

[0028] Arrange a plurality of heat dissipation blind holes on the substrate, fill each heat dissipation blind hole with heat conductive heat dissipation material, and fill the heat conductive heat dissipation material in each heat dissipation blind hole with high resistance material to form a total reflection structure;

[0029] Disposing a second electrode layer on the temporary substrate, and disposing a piezoelectric layer on the second electrode layer; and disposing a first electrode layer on the piezoelectric layer;

[0030] Covering the first electrode layer on the openings of all heat dissipation blind vias, and removing the temporary substrate;

[0031] The second electrode layer, the piezoelectric layer, and the first electrode layer are patterned to obtain a patterned second electrode layer, a patterned piezoelectric layer, and a patterned first electrode layer, wherein the patterned first electrode layer covers the openings of all heat dissipation blind vias.

[0032] The beneficial effects of the method for preparing a thin film bulk acoustic resonator as described in any one of the above items of the present invention are as follows:

[0033] The preparation process is simple, and the full reflection structure is prepared on the substrate, and each heat dissipation blind hole is filled with thermal conductive heat dissipation material and high-resistance material. The prepared thin film bulk acoustic wave resonator maintains the original high Q value while solving the temperature influence caused by insufficient heat conduction capacity of traditional thin film bulk acoustic wave resonators. The structure has strong reliability and is conducive to integration.

[0034] Furthermore, the step of providing a second electrode layer on the temporary substrate includes:

[0035] providing an adhesive layer on the temporary substrate, and providing a second electrode layer on the adhesive layer;

[0036] The removing of the temporary substrate comprises:

[0037] The temporary substrate and the adhesive layer are removed.

[0038] A thin film bulk acoustic wave filter of the present invention includes a thin film bulk acoustic wave resonator as described in any one of the above items. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Schematic diagram of the structure of a thin film bulk acoustic resonator according to an embodiment of the present invention;

[0040] Figure 2 This is a schematic diagram of a process for preparing a thin film bulk acoustic resonator according to an embodiment of the present invention;

[0041] Figure 3 A schematic diagram of a structure in which multiple heat dissipation blind vias are arranged on a substrate;

[0042] Figure 4 A schematic diagram of the structure of filling each heat dissipation blind hole with heat conductive heat dissipation material;

[0043] Figure 5 A schematic diagram of a structure in which a high-resistance material is filled above the heat-conducting heat-dissipating material in each heat-dissipating blind hole;

[0044] Figure 6 A schematic diagram of the structure for setting the first electrode layer;

[0045] Figure 7 A schematic structural diagram of patterning the first electrode layer;

[0046] Figure 8 A schematic diagram of the structure for setting the piezoelectric layer;

[0047] Figure 9 A schematic diagram of the structure for setting the second electrode layer;

[0048] Figure 10 A schematic structural diagram of patterning the second electrode layer;

[0049] Figure 11 A second flow chart of a method for preparing a thin film bulk acoustic resonator according to an embodiment of the present invention;

[0050] Figure 12 is a schematic structural diagram of a temporary substrate, an adhesive layer, and a second electrode layer;

[0051] Figure 13 A schematic diagram of a structure in which a first electrode layer is provided on a piezoelectric layer;

[0052] Figure 14 A schematic diagram of a structure in which the first electrode layer covers the openings of all heat dissipation blind vias;

[0053] Figure 15 Schematic diagram of the structure for removing the temporary substrate and adhesive layer;

[0054] Figure 16 A schematic structural diagram of patterning the second electrode layer;

[0055] Figure 17 A schematic diagram of the structure for patterning the piezoelectric layer;

[0056] In the accompanying drawings, the components represented by the reference numerals are as follows:

[0057] 10. Patterned second electrode layer; 11. Second electrode layer; 20. Patterned piezoelectric layer; 21. Piezoelectric layer; 30. Patterned first electrode layer; 31. First electrode layer; 40. High-resistance material; 50. Thermally conductive and heat-dissipating material; 60. Substrate; 70. Heat-dissipating blind vias; 80. Temporary substrate; 90. Adhesive layer. DETAILED DESCRIPTION

[0058] like Figure 1 As shown, a thin film bulk acoustic wave resonator according to an embodiment of the present invention includes: a patterned second electrode layer 10, a patterned piezoelectric layer 20, a patterned first electrode layer 30 and a substrate 60;

[0059] The patterned second electrode layer 10, the patterned piezoelectric layer 20, the patterned first electrode layer 30 and the substrate 60 are stacked in sequence;

[0060] A plurality of heat dissipation blind vias 70 are arranged on the substrate 60, each heat dissipation blind via 70 is filled with a thermally conductive heat dissipation material 50, and a high-resistance material 40 is filled above the thermally conductive heat dissipation material 50 in each heat dissipation blind via 70 to form a total reflection structure, and the patterned first electrode layer 30 is covered on the openings of all heat dissipation blind vias 70.

[0061] A total reflection structure is prepared on a substrate 60, and a thermally conductive heat dissipation material 50 and a high-resistance material 40 are filled in each heat dissipation blind hole 70. This allows a thin film bulk acoustic wave resonator of the present application to maintain its original high Q value while also solving the temperature influence caused by insufficient heat conduction capacity of traditional thin film bulk acoustic wave resonators. The structure has strong reliability, is conducive to integration, and has a simple preparation process.

[0062] The substrate 60 is made of Si, SiC or sapphire.

[0063] The thermally conductive and heat dissipating material 50 includes at least one of graphite, graphene, graphite oxide, copper, gold, silver, aluminum, diamond and high thermal conductivity silicon.

[0064] The high-resistance material 40 includes at least one of silicon dioxide and high-resistance silicon.

[0065] like Figure 2 As shown, a method for preparing a thin film bulk acoustic resonator according to an embodiment of the present invention includes:

[0066] S1. Arrange a plurality of heat dissipation blind vias 70 on a substrate 60, fill each heat dissipation blind via 70 with a heat conductive heat dissipation material 50, and fill each heat dissipation blind via 70 with a high resistance material 40 above the heat conductive heat dissipation material 50 to form a total reflection structure;

[0067] S2. Covering the first electrode layer 31 on the substrate 60 and on the openings of all the heat dissipation blind vias 70 , and patterning the first electrode layer 31 to form a patterned first electrode layer 30 , wherein the patterned first electrode layer 30 covers the openings of all the heat dissipation blind vias 70 ;

[0068] S3, disposing a piezoelectric layer 21 on the patterned first electrode layer 30, and disposing a second electrode layer 11 on the piezoelectric layer 21;

[0069] S4 , patterning the second electrode layer 11 and the piezoelectric layer 21 to form a patterned second electrode layer 10 and a patterned piezoelectric layer 20 .

[0070] S1 to S4 are described in detail by the following examples, specifically:

[0071] S10, pre-processing the substrate 60 and defining the position of each heat dissipation blind via 70 by photolithography, wherein the material of the substrate 60 includes but is not limited to Si-based material, SiC material, and sapphire material;

[0072] S11, using etching or laser drilling methods, open each heat dissipation blind hole 70 on the substrate 60 after the previous photolithography process, such as Figure 3 As shown, in order to obtain a total reflection structure, the distribution of the heat dissipation blind holes 70 and the depth of the heat dissipation blind holes 70 can be calculated according to parameters such as the wavelength of the sound wave to be resonated.

[0073] S12, perform sidewall sputtering and fill each heat dissipation blind hole 70 with heat conductive heat dissipation material 50 by electroplating, sputtering, evaporation and other related methods, such as Figure 4 As shown, the thermal conductive heat dissipation material 50 includes but is not limited to one or more combinations of related thermal conductive materials or heat dissipation materials. The thermal conductive materials include: graphite, graphene, graphite oxide and other thermally conductive materials; the heat dissipation materials include: metal materials such as copper, gold, silver, aluminum, non-metallic materials such as diamond, high thermal conductivity silicon and other doped composite materials.

[0074] S13, performing surface treatment on the substrate 60 in S12 to remove excess filler, i.e., the heat-conducting and heat-dissipating material 50, and other surface impurities deposited on the surface of the substrate 60 during the filling process. If no excess filler is deposited on the surface of the substrate 60 during the filling process, and no other surface impurities are present, the process proceeds directly to S14;

[0075] S14, using sputtering, evaporation and filling curing methods, fill the high resistance material 40 above the heat conductive heat dissipation material 50 in each heat dissipation blind hole 70, such as Figure 5 As shown, the high-resistance material 40 includes but is not limited to inorganic materials such as silicon dioxide, high-resistance silicon, high-resistivity organic materials and other composite materials;

[0076] S15, performing surface treatment on the substrate 60 after being filled with the high-resistance material 40 in S14, removing excess filler (i.e., excess high-resistance material 40) generated on the surface of the substrate 60 during the filling process of the high-resistance material 40 by CMP or etching or other related process methods, and performing surface planarization;

[0077] S16, a first electrode layer 31 is formed on the substrate 60 and on the openings of all the heat dissipation blind vias 70, as shown in FIG. Figure 6 As shown;

[0078] S17, patterning the first electrode layer 31 to form a patterned first electrode layer 30, such as Figure 7 As shown, the specific implementation method of patterning is well known to those skilled in the art and will not be elaborated here. The patterned first electrode layer 30 can cover the openings of all the heat dissipation blind vias 70.

[0079] S18, a piezoelectric layer 21 is provided on the patterned first electrode layer 30. Since it is difficult to precisely control the piezoelectric layer 21 provided on the first electrode layer 31, the piezoelectric layer 21 may be provided on the substrate 60 as a whole, as shown in FIG. Figure 8 As shown;

[0080] S19, a second electrode layer 11 is provided on the piezoelectric layer 21. To reduce the difficulty of the process, the second electrode layer 11 can be provided on the substrate 60 as a whole. Figure 9 As shown;

[0081] S20, patterning the second electrode layer 11 to form a patterned second electrode layer 10, such as Figure 10 As shown;

[0082] S21, patterning the piezoelectric layer 21 to form a patterned piezoelectric layer 20, thereby obtaining a thin film bulk acoustic resonator of the present application, such as Figure 1 As shown;

[0083] The preparation process from S10 to S21 is simple, and a total reflection structure is prepared on a substrate 60, and a thermal conductive heat dissipation material 50 and a high-resistance material 40 are filled in each heat dissipation blind hole 70, so that the prepared thin film bulk acoustic wave resonator can maintain the original high Q value while solving the temperature influence caused by the insufficient heat conduction capacity of the traditional thin film bulk acoustic wave resonator, and has strong structural reliability and is conducive to integration.

[0084] like Figure 11 As shown, a method for preparing a thin film bulk acoustic resonator according to any one of the above items of the present invention comprises:

[0085] S100, laying out a plurality of heat dissipation blind vias 70 on a substrate 60, filling each heat dissipation blind via 70 with a heat conductive heat dissipation material 50, and filling a high resistance material 40 above the heat conductive heat dissipation material 50 in each heat dissipation blind via 70 to form a total reflection structure;

[0086] S101, disposing a second electrode layer 11 on a temporary substrate 80, and disposing a piezoelectric layer 21 on the second electrode layer 11; and disposing a first electrode layer 31 on the piezoelectric layer 21;

[0087] S102, covering the first electrode layer 31 on the openings of all heat dissipation blind vias 70, and removing the temporary substrate 80;

[0088] S103, patterning the second electrode layer 11, the piezoelectric layer 21, and the first electrode layer 31 to obtain a patterned second electrode layer 10, a patterned piezoelectric layer 20, and a patterned first electrode layer 30, wherein the patterned first electrode layer 30 covers the openings of all heat dissipation blind holes 70.

[0089] Preferably, in the above technical solution, the step of providing the second electrode layer 11 on the temporary substrate 80 includes:

[0090] An adhesive layer 90 is provided on the temporary substrate 80 , and a second electrode layer 11 is provided on the adhesive layer 90 ;

[0091] The removing of the temporary substrate 80 comprises:

[0092] The temporary substrate 80 and the adhesive layer 90 are removed.

[0093] S100 to S104 are described in detail through the following examples, specifically:

[0094] S1000, pre-processing the substrate 60 and defining the position of each heat dissipation blind via 70 by photolithography. The material of the substrate 60 includes but is not limited to Si-based materials, SiC materials, and sapphire materials;

[0095] S1001, using etching or laser drilling methods, open each heat dissipation blind hole 70 on the substrate 60 after the previous photolithography process, such as Figure 3 As shown, in order to obtain a total reflection structure, the distribution of the heat dissipation blind holes 70 and the depth of the heat dissipation blind holes 70 can be calculated according to parameters such as the wavelength of the sound wave to be resonated.

[0096] S1002, perform sidewall sputtering and fill each heat dissipation blind hole 70 with heat conductive heat dissipation material 50 by electroplating, sputtering, evaporation or other related methods, such as Figure 4 As shown, the thermal conductive heat dissipation material 50 includes but is not limited to one or more combinations of related thermal conductive materials or heat dissipation materials. The thermal conductive materials include: graphite, graphene, graphite oxide and other thermally conductive materials; the heat dissipation materials include: metal materials such as copper, gold, silver, aluminum, non-metallic materials such as diamond, high thermal conductivity silicon and other doped composite materials.

[0097] S1003, performing surface treatment on the substrate 60 in S1002 to remove excess filler, i.e., the heat-conducting and heat-dissipating material 50, and other surface impurities deposited on the surface of the substrate 60 during the filling process. If no excess filler is deposited on the surface of the substrate 60 during the filling process, and no other surface impurities are present, the process proceeds directly to S1004;

[0098] S1004, using sputtering, evaporation and filling curing methods, fill the high resistance material 40 above the heat conductive heat dissipation material 50 in each heat dissipation blind hole 70, such as Figure 5 As shown, the high-resistance material 40 includes but is not limited to inorganic materials such as silicon dioxide, high-resistance silicon, high-resistivity organic materials and other composite materials;

[0099] S1005, performing surface treatment on the substrate 60 after being filled with the high-resistance material 40 in S1004, removing excess filler (i.e., excess high-resistance material 40) generated on the surface of the substrate 60 during the filling process of the high-resistance material 40 by CMP or etching or other related process methods, and performing surface planarization;

[0100] S1006, setting an adhesive layer 90 on the temporary substrate 80, and setting a second electrode layer 11 on the adhesive layer 90, as shown in FIG. Figure 12 As shown;

[0101] S1007, disposing a piezoelectric layer 21 on the second electrode layer 11, and disposing a first electrode layer 31 on the piezoelectric layer 21, as shown in FIG. Figure 13 As shown;

[0102] S1008, covering the first electrode layer 31 on the openings of all the heat dissipation blind holes 70, such as Figure 14 As shown;

[0103] S1009, removing the temporary substrate 80 and the adhesive layer 90, as shown in FIG. Figure 15 As shown;

[0104] S1010, patterning the second electrode layer 11 to obtain a patterned second electrode layer 10, such as Figure 16 As shown;

[0105] S1010, patterning the piezoelectric layer 21 to obtain a patterned piezoelectric layer 20, such as Figure 17 As shown;

[0106] S1011, patterning the first electrode layer 31 to form a patterned first electrode layer 30, thereby obtaining a thin film bulk acoustic resonator of the present application, such as Figure 1 As shown;

[0107] The preparation process from S1000 to S1001 is simple, and a total reflection structure is prepared on a substrate 60, and a thermal conductive heat dissipation material 50 and a high-resistance material 40 are filled in each heat dissipation blind hole 70. This allows the prepared thin film bulk acoustic wave resonator to maintain its original high Q value while also solving the temperature influence caused by insufficient heat conduction capacity of traditional thin film bulk acoustic wave resonators. The structure has strong reliability and is conducive to integration.

[0108] In the above embodiments, although the steps are numbered S1, S2, etc., these are only specific embodiments given in this application. Those skilled in the art can adjust the execution order of S1, S2, etc. according to actual conditions, which is also within the scope of protection of the present invention. It can be understood that in some embodiments, some or all of the above embodiments may be included.

[0109] A thin film bulk acoustic wave filter according to an embodiment of the present invention includes a thin film bulk acoustic wave resonator as described in any one of the above items.

[0110] In the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0111] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0112] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A thin film bulk acoustic resonator, characterized in that: include: A patterned second electrode layer, a patterned piezoelectric layer, a patterned first electrode layer, and a substrate; The patterned second electrode layer, the patterned piezoelectric layer, the patterned first electrode layer and the substrate are stacked in sequence; A plurality of heat dissipation blind holes are arranged on the substrate, and each heat dissipation blind hole is filled with a heat conductive heat dissipation material and a high-resistance material, and the high-resistance material forms a total reflection structure above the heat conductive heat dissipation material, and the patterned first electrode layer covers the openings of all the heat dissipation blind holes; The distribution of the heat dissipation blind holes and the depth of the heat dissipation blind holes are calculated according to the wavelength of the sound wave to be resonated.

2. The thin film bulk acoustic resonator according to claim 1, characterized in that: The substrate is made of Si, SiC or sapphire.

3. The thin film bulk acoustic resonator according to claim 1, characterized in that: The thermally conductive and heat dissipating material includes at least one of graphite, graphene, graphite oxide, copper, gold, silver, aluminum, diamond and high thermal conductivity silicon.

4. The thin film bulk acoustic resonator according to claim 1, characterized in that: The high-resistance material includes at least one of silicon dioxide and high-resistance silicon.

5. A method for preparing a thin film bulk acoustic resonator according to any one of claims 1 to 4, characterized in that: include: Arrange a plurality of heat dissipation blind holes on the substrate, fill each heat dissipation blind hole with heat conductive heat dissipation material, and fill the heat conductive heat dissipation material in each heat dissipation blind hole with high resistance material to form a total reflection structure; A first electrode layer is provided on the substrate and covers the openings of all the heat dissipation blind vias, and the first electrode layer is patterned to form a patterned first electrode layer, wherein the patterned first electrode layer covers the openings of all the heat dissipation blind vias; Disposing a piezoelectric layer on the patterned first electrode layer, and disposing a second electrode layer on the piezoelectric layer; The second electrode layer and the piezoelectric layer are patterned to form a patterned second electrode layer and a patterned piezoelectric layer.

6. A method for preparing a thin film bulk acoustic resonator according to any one of claims 1 to 4, characterized in that: include: Arrange a plurality of heat dissipation blind holes on the substrate, fill each heat dissipation blind hole with heat conductive heat dissipation material, and fill the heat conductive heat dissipation material in each heat dissipation blind hole with high resistance material to form a total reflection structure; providing a second electrode layer on the temporary substrate, and providing a piezoelectric layer on the second electrode layer; and disposing a first electrode layer on the piezoelectric layer; Covering the first electrode layer on the openings of all heat dissipation blind vias, and removing the temporary substrate; The second electrode layer, the piezoelectric layer, and the first electrode layer are patterned to obtain a patterned second electrode layer, a patterned piezoelectric layer, and a patterned first electrode layer, wherein the patterned first electrode layer covers the openings of all heat dissipation blind vias.

7. A preparation method according to claim 6, characterized in that, The step of providing a second electrode layer on the temporary substrate comprises: providing an adhesive layer on the temporary substrate, and providing a second electrode layer on the adhesive layer; The removing of the temporary substrate comprises: The temporary substrate and the adhesive layer are removed.

8. A thin film bulk acoustic wave filter, characterized in that: A thin film bulk acoustic resonator comprising any one of claims 1 to 4.

Images