Composite piezoelectric substrate and preparation method and application thereof

Abstract

The invention discloses a composite piezoelectric substrate and a preparation method and application thereof, and belongs to the technical field of semiconductor materials. The preparation method of the composite piezoelectric substrate comprises the following steps: acquiring a piezoelectric wafer and a substrate wafer; depositing a first bonding layer on the first surface of the piezoelectric wafer, and depositing a second bonding layer on the to-be-bonded surface of the substrate wafer; ion implantation is carried out inwards in the first surface direction of the piezoelectric wafer, and an ion implantation damage layer is formed in the piezoelectric wafer; bonding the first bonding layer of the piezoelectric wafer and the second bonding layer of the substrate wafer to obtain a bonding body; performing annealing stripping treatment on the bonding body to separate the bonding body along the ion implantation damage layer to obtain the composite piezoelectric substrate; the composite piezoelectric substrate sequentially comprises a substrate wafer, a second bonding layer, a first bonding layer and a piezoelectric single crystal film from bottom to top. According to the method, the bonding strength and the yield are remarkably improved.

Description

Technical Field

[0001] The present application relates to a composite piezoelectric substrate and a preparation method and application thereof, belonging to the technical field of semiconductor materials. Background Art

[0002] With the rapid development of mobile communication technology and the full coverage of 5G wireless networks, the performance requirements of RF front-end modules have increased significantly. Filters, as core components of RF front-ends, are evolving towards higher frequencies, larger bandwidths, lower losses, and better temperature stability. At present, new structural acoustic filters based on piezoelectric single crystal films are expected to become the mainstream of 5G communication filter development. Piezoelectric single crystal films are heterogeneously integrated with insulating substrates at the wafer level, and the synergistic optimization of multi-layer materials further enhances the overall performance of the device, giving it greater application potential in the next generation of communication technologies.

[0003] Ion beam stripping is currently the most commonly used method for preparing large-area piezoelectric single crystal films, which generally includes steps such as ion implantation, wafer heterobonding and thermal stripping. However, due to the different materials of the piezoelectric wafer and the substrate, the chemical properties of the surface dangling bonds are quite different, and the interface strength of the bonded body formed by wafer bonding is not high, which leads to the bonded body being easily debonded during the subsequent heating and stripping process, and the single crystal film cannot be transferred. In addition, the difference in thermal expansion coefficients between the piezoelectric material and the substrate causes the bonded body to introduce large thermal stress. When the thermal stress is greater than the bonding strength, the bonded body is prone to debonding, wafer slippage and cracking, which leads to a significant decrease in the yield of the composite piezoelectric substrate.

[0004] Therefore, there is an urgent need to provide a method for preparing a composite piezoelectric substrate that is simple and easy to operate, has high bonding strength, is easy to peel and transfer piezoelectric single crystal thin films, and has a high yield rate to meet the needs of large-scale industrial production. Summary of the invention

[0005] In order to solve the above problems, a composite piezoelectric substrate and a preparation method and application thereof are provided. The method realizes homogeneous bonding by depositing a first bonding layer and a second bonding layer, which, on the one hand, realizes wafer-level heterogeneous bonding between the piezoelectric material and the substrate material; on the other hand, the bonding strength is greatly improved, avoiding debonding of the bonded body during the subsequent annealing and stripping process to obtain the piezoelectric single crystal film, and significantly improving the yield. In the present application, the first bonding layer is first deposited on the piezoelectric wafer and then ion implantation is performed, which effectively avoids the peeling of the ion implantation damaged layer during the deposition of the first bonding layer, resulting in the failure of the piezoelectric single crystal film transfer.

[0006] According to one aspect of the present application, a method for preparing a composite piezoelectric substrate is provided, comprising the following steps:

[0007] (1) Obtaining a piezoelectric wafer and a substrate wafer;

[0008] (2) depositing a first adhesive layer on the first surface of the piezoelectric wafer and depositing a second adhesive layer on the surface to be bonded of the substrate wafer;

[0009] (3) performing ion implantation inwardly toward the first surface of the piezoelectric wafer to form an ion implantation damage layer inside the piezoelectric wafer;

[0010] (4) bonding the first bonding layer of the piezoelectric wafer and the second bonding layer of the substrate wafer to obtain a bonded body;

[0011] (5) performing annealing and peeling treatment on the bonded body to separate the bonded body along the ion implantation damage layer to obtain a composite piezoelectric substrate;

[0012] The composite piezoelectric substrate comprises, from bottom to top, a substrate wafer, a second adhesive layer, a first adhesive layer, and a piezoelectric single crystal film.

[0013] Specifically, the piezoelectric wafer of the present application is first deposited with a first bonding layer and then ion implanted, rather than the conventional method of first implanting ions and then growing the bonding layer. This is because the stripping temperature of the damaged layer is 80-250°C, and the temperature for depositing the first bonding layer is 200-600°C. If ion implantation is performed first and then the first bonding layer is deposited, it is easy to cause the ion implanted damaged layer to be peeled off in advance during the deposition of the bonding layer, resulting in the failure of the piezoelectric single crystal film transfer.

[0014] Optionally, the first adhesive layer and the second adhesive layer are made of the same material, and the material of the first adhesive layer and the second adhesive layer includes silicon oxide, silicon nitride, polycrystalline silicon or amorphous silicon.

[0015] Specifically, in the present application, the first bonding layer and the second bonding layer are made of the same material, and the first bonding layer and the second bonding layer are homogeneously bonded. On the one hand, wafer-level heterogeneous bonding of the piezoelectric material and the substrate material can be achieved. On the other hand, the homogeneous bonding of the first bonding layer and the second bonding layer greatly improves the bonding strength of the bonded body, thereby avoiding debonding of the bonded body during the subsequent annealing and peeling process to obtain the piezoelectric single crystal thin film, thereby significantly improving the yield.

[0016] Optionally, the thickness of the first adhesive layer and the second adhesive layer is 0.001-1 μm; and / or the thickness of the piezoelectric single crystal film is 0.01-3 μm.

[0017] Specifically, the present application sets limits on the thickness of the first adhesive layer and the second adhesive layer. On the one hand, when the thickness of the first adhesive layer and the second adhesive layer is too thick, a higher ion implantation energy is required to form a damaged layer at a preset depth in the piezoelectric wafer. Using too high energy to implement ion implantation will, on the one hand, lead to an increase in the degree of damage to the crystal quality of the piezoelectric wafer, thereby making the single crystal quality of the prepared piezoelectric single crystal film poor. On the other hand, using too high energy to implement ion implantation places more stringent requirements on the process stability of the high-energy ion implanter, and will also lead to a decrease in the product yield.

[0018] Optionally, in step (2), the first bonding layer and the second bonding layer are obtained by low-pressure chemical vapor deposition, with a deposition temperature of 200-600°C, a power of 75-300W, a gas pressure of 50-300Pa, a silane gas flow rate of 1-20sccm, a nitrogen flow rate of 100-500sccm, and a nitric oxide flow rate of 100-500sccm.

[0019] Specifically, the present application makes specific restrictions on the process parameters for depositing the first adhesive layer and the second adhesive layer so that the in-plane thickness distribution difference of the deposited first adhesive layer and the second adhesive layer is less than 1 nm; the surface roughness is less than 0.5 nm, so as to improve the bonding strength.

[0020] Optionally, the ion species of the ion implantation in step (3) are hydrogen ions and / or helium ions; the implantation energy of the ion implantation is 10 to 500 keV, and the implantation dose is 5×10 15 ~5×10 17 ions / cm 2 .

[0021] Specifically, the present application limits the process conditions of ion implantation. On the one hand, the process parameters of ion implantation are closely related to the thickness of the bonding layer. On the other hand, the process parameters of ion implantation also determine the thickness of the piezoelectric single crystal film. Excessive ion implantation energy leads to increased damage to the crystal quality of the piezoelectric wafer. Excessive ion implantation energy leads to the formation of an ion implantation damage layer within a smaller depth range. The thickness of the piezoelectric single crystal film finally peeled off is lower than the expected value.

[0022] Optionally, the annealing temperature of the annealing stripping in step (5) is 80 to 250° C., the annealing time is 1 to 50 hours, and the annealing atmosphere is nitrogen or an inert gas.

[0023] Specifically, the present application makes specific restrictions on the temperature, time, annealing atmosphere, etc. of annealing peeling. Among them, if the annealing temperature is too high, bonding structure fragments will appear during the annealing peeling process, and if the annealing temperature is too low, the peeling degree of the piezoelectric single crystal film will be incomplete; if the annealing time is too short, the peeling degree of the piezoelectric single crystal film will be incomplete, and if the annealing time is too long, the preparation time will be extended and the production efficiency will be reduced.

[0024] Optionally, the material of the piezoelectric wafer includes lithium tantalate, lithium niobate, quartz, lanthanum gallium silicate or lithium tetraborate; the material of the substrate wafer includes silicon, silicon carbide, sapphire, quartz or diamond.

[0025] Optionally, the bonding in step (4) adopts hydrophilic bonding or room temperature bonding.

[0026] Specifically, the present application does not make specific limitations on the specific process parameters of bonding, and those skilled in the art may make selections based on actual conditions.

[0027] Specifically, according to the preparation method of the present application, the bonding between the substrate wafer and the piezoelectric wafer can be achieved by using hydrophilic bonding and room temperature bonding, and the bonding strength is also greatly improved.

[0028] According to another aspect of the present application, a composite piezoelectric substrate prepared by the above-mentioned method for preparing the composite piezoelectric substrate is also provided.

[0029] According to another aspect of the present application, there is also provided a composite piezoelectric substrate prepared by the above-mentioned method for preparing the composite piezoelectric substrate or the application of the above-mentioned composite piezoelectric substrate in filters, integrated optoelectronic devices, and magnetoacoustic antenna devices.

[0030] The beneficial effects of this application include but are not limited to:

[0031] 1. According to the preparation method of the composite piezoelectric substrate of the present application, the method realizes homogeneous bonding by depositing a first bonding layer and a second bonding layer, which, on the one hand, realizes wafer-level heterogeneous bonding between the piezoelectric material and the substrate material; on the other hand, it greatly improves the bonding strength, avoids debonding of the bonded body during the subsequent annealing and stripping process to obtain the piezoelectric single crystal film, and significantly improves the yield; the present application first deposits the first bonding layer on the piezoelectric wafer and then performs ion implantation, which effectively avoids the peeling of the ion implantation damaged layer during the deposition of the first bonding layer, resulting in failure of the piezoelectric single crystal film transfer.

[0032] 2. According to the preparation method of the composite piezoelectric substrate of the present application, the present application sets a limit on the thickness of the first bonding layer and the second bonding layer. On the one hand, when the thickness of the first bonding layer and the second bonding layer is too thick, a higher ion implantation energy is required to form a damage layer at a preset depth in the piezoelectric wafer. Using too high energy to implement ion implantation will, on the one hand, lead to an increase in the degree of damage to the crystal quality of the piezoelectric wafer, thereby making the single crystal nature of the prepared piezoelectric single crystal film poor; on the other hand, using too high energy to implement ion implantation will place more stringent requirements on the process stability of the high-energy ion implanter, and will also lead to a reduction in the product yield.

[0033] 3. According to the preparation method of the composite piezoelectric substrate of the present application, the present application limits the process conditions of ion implantation. On the one hand, the process parameters of ion implantation are closely related to the thickness of the bonding layer. On the other hand, the process parameters of ion implantation also determine the thickness of the piezoelectric single crystal film. Excessive ion implantation energy leads to increased damage to the crystal quality of the piezoelectric wafer. Excessive low ion implantation energy leads to the formation of an ion implantation damage layer within a smaller depth range. The thickness of the piezoelectric single crystal film finally peeled off is lower than the expected value.

[0034] 4. According to the preparation method of the composite piezoelectric substrate of the present application, a composite piezoelectric substrate and piezoelectric wafer residues are finally obtained. After polishing and other related treatments, the piezoelectric wafer residues can be used as piezoelectric wafers to repeat the preparation method of the composite piezoelectric substrate and be recycled. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0036] Figure 1 This is a schematic diagram of the process flow for preparing a composite piezoelectric substrate involved in Example 1 of the present application.

[0037] Figure 2 This is a schematic diagram of the structural process of preparing a composite piezoelectric substrate involved in Example 1 of the present application.

[0038] Figure 3 This is a schematic diagram of the structure of depositing the first adhesive layer on the piezoelectric wafer involved in Example 1 of the present application.

[0039] Figure 4 This is a schematic diagram of the structure of depositing a second adhesive layer on the substrate wafer involved in Example 1 of the present application.

[0040] Figure 5 This is a schematic diagram of the piezoelectric wafer ion implantation structure involved in Example 1 of the present application.

[0041] Figure 6 This is a schematic diagram of the structure of the bonding body prepared in Example 1 of the present application.

[0042] Figure 7 This is a schematic diagram of the structure of the bond body annealing and peeling involved in Example 1 of the present application.

[0043] Figure 8 This is a wafer edge morphology image after annealing and peeling of the bonded body involved in Example 1 of the present application.

[0044] Fig. 9 This is a morphology image of the wafer edge after annealing and peeling of the bonded body involved in Comparative Example 1 of the present application.

[0045] Fig.10 This is a diagram of the admittance signal of the surface acoustic wave resonator involved in Example 1 and Comparative Example 1 of the present application.

[0046] List of parts and reference numerals:

[0047] 100. piezoelectric wafer; 200. substrate wafer; 101. first bonding layer; 102 ion implantation damaged layer; 103. piezoelectric single crystal film; 201. second bonding layer; 400. piezoelectric wafer residue. DETAILED DESCRIPTION

[0048] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0049] Unless otherwise specified, the raw materials in the examples and comparative examples of the present application were purchased through commercial channels.

[0050] Unless otherwise specified, the methods used in the examples and comparative examples of the present application are conventional methods in the prior art.

[0051] Example 1

[0052] A method for preparing a composite piezoelectric substrate

[0053] (1) obtaining a piezoelectric wafer and a substrate wafer, wherein the piezoelectric wafer is made of 15° Y-cut lithium niobate with a thickness of 350 μm, and the substrate wafer is made of 4H crystalline silicon carbide with a thickness of 500 μm;

[0054] (2) depositing a first adhesive layer on the first surface of the piezoelectric wafer, and depositing a second adhesive layer on the surface to be bonded of the substrate wafer, wherein the first adhesive layer and the second adhesive layer are both made of silicon dioxide, and both have a thickness of 4 nm. The first adhesive layer and the second adhesive layer are deposited by low-pressure chemical vapor deposition, and the deposition temperature is 400° C., the power is 150 W, the gas pressure is 130 Pa, the silane gas flow rate is 9 sccm, the nitrogen flow rate is 200 sccm, and the nitric oxide flow rate is 240 sccm;

[0055] (3) Ion implantation is performed inwardly on the first surface of the piezoelectric wafer. Helium ions are used for ion implantation. The implantation energy is 200 keV and the dose of the implanted ions is 2×10 16 ions / cm 2 The implantation time is 6 hours, and an ion implantation damage layer is formed inside the piezoelectric wafer;

[0056] (4) bonding the first bonding layer of the piezoelectric wafer and the second bonding layer of the substrate wafer to obtain a bonded body, with a bonding temperature of 50° C. and a bonding pressure of 2000 mbar;

[0057] (5) performing annealing and peeling treatment on the bonded body, the annealing temperature is 240° C., the annealing time is 10 h, and the annealing atmosphere is nitrogen, so that the bonded body is separated along the ion implantation damage layer to obtain a composite piezoelectric substrate;

[0058] The composite piezoelectric substrate comprises, from bottom to top, a substrate wafer, a second adhesive layer, a first adhesive layer, and a piezoelectric single crystal film.

[0059] Example 2

[0060] A method for preparing a composite piezoelectric substrate

[0061] (1) obtaining a piezoelectric wafer and a substrate wafer, wherein the piezoelectric wafer is made of 42° Y-cut lithium tantalate with a thickness of 350 μm, and the substrate wafer is made of silicon with a thickness of 500 μm;

[0062] (2) depositing a first adhesive layer on the first surface of the piezoelectric wafer, and depositing a second adhesive layer on the surface to be bonded of the substrate wafer, wherein the first adhesive layer and the second adhesive layer are both made of silicon dioxide, and both have a thickness of 1 μm, and are deposited by low-pressure chemical vapor deposition, with a deposition temperature of 600° C., a power of 300 W, a gas pressure of 300 Pa, a silane gas flow rate of 20 sccm, a nitrogen flow rate of 500 sccm, and a nitric oxide flow rate of 500 sccm;

[0063] (3) Ion implantation is performed inwardly on the first surface of the piezoelectric wafer. Helium ions are used for ion implantation. The implantation energy is 500 keV and the implantation dose is 5×10 17 ions / cm 2 The implantation time is 6 hours, and an ion implantation damage layer is formed inside the piezoelectric wafer;

[0064] (4) bonding the first bonding layer of the piezoelectric wafer and the second bonding layer of the substrate wafer to obtain a bonded body, with a bonding temperature of 50° C. and a bonding pressure of 2000 mbar;

[0065] (5) performing annealing and peeling treatment on the bonded body, the annealing temperature is 250° C., the annealing time is 1 h, and the annealing atmosphere is helium, so that the bonded body is separated along the ion implantation damage layer to obtain a composite piezoelectric substrate;

[0066] The composite piezoelectric substrate comprises, from bottom to top, a substrate wafer, a second adhesive layer, a first adhesive layer, and a piezoelectric single crystal film.

[0067] Example 3

[0068] A method for preparing a composite piezoelectric substrate

[0069] (1) obtaining a piezoelectric wafer and a substrate wafer, wherein the piezoelectric wafer is made of 42° Y-cut lithium tantalate with a thickness of 350 μm, and the substrate wafer is made of quartz with a thickness of 500 μm;

[0070] (2) depositing a first adhesive layer on the first surface of the piezoelectric wafer, and depositing a second adhesive layer on the surface to be bonded of the substrate wafer, wherein the first adhesive layer and the second adhesive layer are both made of silicon dioxide, and both have a thickness of 0.5 μm, and the first adhesive layer and the second adhesive layer are deposited by low-pressure chemical vapor deposition, with a deposition temperature of 200° C., a power of 75 W, a gas pressure of 50 Pa, a silane gas flow rate of 1 sccm, a nitrogen flow rate of 100 sccm, and a nitric oxide flow rate of 100 sccm;

[0071] (3) Ion implantation is performed inwardly on the first surface of the piezoelectric wafer. Helium ions are used for ion implantation. The implantation energy is 10 keV and the dose of the implanted ions is 5×10 15 ions / cm 2 The implantation time is 6 hours, and an ion implantation damage layer is formed inside the piezoelectric wafer;

[0072] (4) bonding the first bonding layer of the piezoelectric wafer and the second bonding layer of the substrate wafer to obtain a bonded body, with a bonding temperature of 50° C. and a bonding pressure of 2000 mbar;

[0073] (5) performing annealing and peeling treatment on the bonded body, the annealing temperature is 80° C., the annealing time is 50 h, and the annealing atmosphere is helium, so that the bonded body is separated along the ion implantation damage layer to obtain a composite piezoelectric substrate;

[0074] The composite piezoelectric substrate comprises, from bottom to top, a substrate wafer, a second adhesive layer, a first adhesive layer, and a piezoelectric single crystal film.

[0075] Example 4

[0076] The difference between Example 4 and Example 1 is that the thickness of the first adhesive layer and the second adhesive layer is 2 μm, and the rest are the same.

[0077] Comparative Example 1

[0078] The difference between Comparative Example 1 and Example 1 is that the preparation of the first adhesive layer and the second adhesive layer is not included, and the rest are the same.

[0079] Comparative Example 2

[0080] The difference between Comparative Example 2 and Example 1 is that the preparation of the second adhesive layer is not included, and the rest is the same.

[0081] Comparative Example 3

[0082] The difference between Comparative Example 3 and Example 1 is that the preparation of the first adhesive layer is not included, and the rest is the same.

[0083] Comparative Example 4

[0084] The difference between Comparative Example 4 and Example 1 is that ion implantation is first performed on the piezoelectric wafer and then the first adhesive layer is deposited, and the rest is the same.

[0085] Experimental Example 1

[0086] The bonding strength of the composite piezoelectric substrates obtained in the above-mentioned embodiments 1 to 4 and comparative examples 1 to 4 was tested by a crack extension method for characterizing the surface energy of the bonding interface; the yield of the composite piezoelectric substrates obtained in embodiments 1 to 4 and comparative examples 1 to 4 was measured, and the test results are shown in Table 1.

[0087] Table 1 Test results of composite piezoelectric substrate

[0088] Group <![CDATA[Bond energy (J / m 2 )]]> Yield rate (%) Example 1 1.15 >70 Example 2 1.11 >70 Example 3 1.09 >70 Example 4 1.01 \ Comparative Example 1 0.53 <20 Comparative Example 2 0.61 <30 Comparative Example 3 0.63 <30 Comparative Example 4 \ 0

[0089] It can be seen from Table 1 that the bonding strength and yield rate of the composite piezoelectric substrates prepared in Examples 1 to 3 are at a high level. In Example 4, the finished composite piezoelectric substrate cannot be obtained because the first adhesive layer and the second adhesive layer are too thick; in Comparative Example 4, ion implantation is performed first and then the first adhesive layer is deposited, resulting in the ion implantation damaged layer being peeled off in advance during the deposition of the adhesive layer, resulting in the failure of the piezoelectric single crystal film transfer, and the finished composite piezoelectric substrate cannot be obtained. Comparative Examples 1 to 3 cannot achieve homogeneous bonding, resulting in a decrease in bonding strength and yield rate compared with Examples 1 to 3.

[0090] Depend on Figure 8 and Fig. 9 It can be obtained that when the bonding bodies of Example 1 and Comparative Example 1 are annealed and peeled, the interface bonding strength of the bonding body provided by Example 1 is improved. After annealing and peeling, the morphology of the piezoelectric single crystal film at the edge of the wafer is complete. After annealing, the piezoelectric single crystal film at the edge of the wafer of the bonding body of Comparative Example 1 is broken. The reason is analyzed to be insufficient bonding strength between the piezoelectric wafer and the substrate wafer.

[0091] Experimental Example 2

[0092] Example 1 and Comparative Example 1 were applied to a surface acoustic wave resonator to test the performance. The test results are as follows: Fig.10 shown.

[0093] Depend on Fig.10 It can be concluded that when the composite piezoelectric substrates of Example 1 and Comparative Example 1 are applied to devices, the surface acoustic wave resonator simulates the admittance signal, and the signals of Example 1 and Comparative Example 1 are correspondingly similar, wherein the admittance ratio and electromechanical coupling coefficient of Example 1 are higher than those of Comparative Example 1.

[0094] Depend on Figure 1 to Figure 7 It can be obtained that a piezoelectric wafer 100 and a substrate wafer 200 are obtained, a first adhesive layer 101 is deposited on a first surface of the piezoelectric wafer 100, a second adhesive layer 201 is deposited on a surface to be bonded of the substrate wafer 200, ions are implanted inwardly in a direction of the first surface of the piezoelectric wafer 100, and an ion implantation damage layer 102 is formed inside the piezoelectric wafer; the first adhesive layer 101 of the piezoelectric wafer 100 and the second adhesive layer 201 of the substrate wafer 200 are bonded to obtain a bonded body, and an annealing and peeling treatment is performed on the bonded body to separate the bonded body along the ion implantation damage layer to obtain a composite piezoelectric substrate;

[0095] The composite piezoelectric substrate includes, from bottom to top, a substrate wafer 200 , a second adhesive layer 201 , a first adhesive layer 101 , and a piezoelectric single crystal film 103 . The piezoelectric wafer residue 400 can be recycled after being processed.

[0096] The above is only the embodiment of the present application, and the protection scope of the present application is not limited by these specific embodiments, but is determined by the claims of the present application. For those skilled in the art, the present application can have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the technical ideas and principles of the present application should be included in the protection scope of the present application.

Claims

1. A method for preparing a composite piezoelectric substrate, characterized in that: The following steps are involved: (1) Obtaining a piezoelectric wafer and a substrate wafer; (2) depositing a first adhesive layer on the first surface of the piezoelectric wafer and depositing a second adhesive layer on the surface to be bonded of the substrate wafer; (3) performing ion implantation inwardly toward the first surface of the piezoelectric wafer to form an ion implantation damage layer inside the piezoelectric wafer; (4) bonding the first bonding layer of the piezoelectric wafer and the second bonding layer of the substrate wafer to obtain a bonded body; (5) performing annealing and peeling treatment on the bonded body to separate the bonded body along the ion implantation damage layer to obtain a composite piezoelectric substrate; The composite piezoelectric substrate comprises, from bottom to top, a substrate wafer, a second adhesive layer, a first adhesive layer, and a piezoelectric single crystal film.

2. The method for preparing a composite piezoelectric substrate according to claim 1, characterized in that: The first adhesive layer and the second adhesive layer are made of the same material, and the material of the first adhesive layer and the second adhesive layer includes silicon oxide, silicon nitride, polysilicon or amorphous silicon.

3. The method for preparing a composite piezoelectric substrate according to claim 1, characterized in that: The thickness of the first adhesive layer and the second adhesive layer is 0.001 to 1 μm; and / or the thickness of the piezoelectric single crystal film is 0.01 to 3 μm.

4. The method for preparing a composite piezoelectric substrate according to claim 1, characterized in that: In step (2), the first bonding layer and the second bonding layer are obtained by low-pressure chemical vapor deposition, with a deposition temperature of 200-600°C, a power of 75-300W, a gas pressure of 50-300Pa, a silane gas flow rate of 1-20sccm, a nitrogen flow rate of 100-500sccm, and a nitric oxide flow rate of 100-500sccm.

5. The method for preparing a composite piezoelectric substrate according to claim 1, characterized in that: The ion species of step (3) ion implantation are hydrogen ions and / or helium ions; the implantation energy of the ion implantation is 10 to 500 keV, and the implantation dose is 5×10 15 ~5×10 17 ions / cm 2 .

6. The method for preparing a composite piezoelectric substrate according to claim 1, characterized in that: The annealing temperature of the annealing stripping in step (5) is 80 to 250° C., the annealing time is 1 to 50 hours, and the annealing atmosphere is nitrogen or an inert gas.

7. The method for preparing a composite piezoelectric substrate according to claim 1, characterized in that: The material of the piezoelectric wafer includes lithium tantalate, lithium niobate, quartz, lanthanum gallium silicate or lithium tetraborate; the material of the substrate wafer includes silicon, silicon carbide, sapphire, quartz or diamond.

8. The method for preparing a composite piezoelectric substrate according to claim 1, characterized in that: In step (4), the bonding is carried out by hydrophilic bonding or room temperature bonding.

9. A composite piezoelectric substrate prepared by the method for preparing a composite piezoelectric substrate according to any one of claims 1 to 8.

10. Use of the composite piezoelectric substrate prepared by the method for preparing a composite piezoelectric substrate according to any one of claims 1 to 8 or the composite piezoelectric substrate according to claim 9 in filters, integrated optoelectronic devices, and magnetoacoustic antenna devices.

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