Silicon carbide wafer and preparation method thereof
By injecting dopant ions into the silicon carbide substrate to form a peeling layer and bonding it to the support substrate, the problems of low preparation efficiency of silicon carbide wafers and waste in the prior art are solved, and an efficient and low-cost preparation process is achieved, and a high-efficiency and low-cost preparation process is improved. The quality and stability of the wafer are achieved.
Patent Information
- Application Number
- CN202411331647.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-24
- Publication Date
- 2025-01-03
AI Technical Summary
The method of preparing silicon carbide wafers in the prior art is time-consuming and labor-intensive, resulting in low production efficiency and waste of materials, increasing manufacturing costs.
The release layer is formed by injecting dopant ions into the silicon carbide substrate, and after activation treatment, the silicon carbide substrate is bonded to the support substrate, and the silicon carbide substrate is divided at the release layer position to form a silicon carbide wafer, reducing the grinding step and recycling use The peeled silicon carbide substrate.
The preparation process of silicon carbide wafers is simplified, the preparation efficiency is improved, the cost is reduced, and the bonding strength between the silicon carbide substrate and the supporting substrate is enhanced through hydrophilic bonding, thereby improving the structural stability of the wafer.
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Figure CN119252764A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of semiconductor manufacturing technology, and in particular to a silicon carbide wafer and a preparation method thereof. Background Art
[0002] Silicon carbide materials are increasingly being used as substrate wafers for high-temperature, high-voltage, and high-power electronic devices due to their stable chemical properties, high thermal conductivity, low thermal expansion coefficient, and good wear resistance. Currently, in order to prepare high-quality silicon carbide wafers, it is usually necessary to grind a silicon carbide substrate with a relatively high thickness, and obtain a silicon carbide wafer of the required thickness by grinding off part of the thickness of the silicon carbide substrate. However, this method of preparing silicon carbide wafers by grinding is not only time-consuming and labor-intensive, resulting in low efficiency in the preparation of silicon carbide wafers, but also causes waste of silicon carbide materials, increasing the manufacturing cost of silicon carbide wafers.
[0003] Therefore, how to simplify the preparation process of silicon carbide wafers, improve the preparation efficiency of silicon carbide wafers, reduce the preparation cost of silicon carbide wafers, and improve the quality of the prepared silicon carbide wafers are technical problems that need to be solved urgently. Summary of the invention
[0004] The present invention provides a silicon carbide wafer and a preparation method thereof, which are used to simplify the preparation process of the silicon carbide wafer, improve the preparation efficiency of the silicon carbide wafer, reduce the preparation cost of the silicon carbide wafer, and improve the quality of the prepared silicon carbide wafer.
[0005] According to some embodiments, the present invention provides a method for preparing a silicon carbide wafer, comprising the following steps:
[0006] Providing a silicon carbide substrate, the silicon carbide substrate comprising a first surface and a second surface oppositely distributed along a first direction;
[0007] Implanting doping ions into the silicon carbide substrate to form a peeling layer in the silicon carbide substrate;
[0008] Activating the first surface of the silicon carbide substrate to form a hydrophilic bonding group on the first surface of the silicon carbide substrate;
[0009] Bonding the silicon carbide substrate to the surface of the supporting substrate with the first surface facing the supporting substrate;
[0010] The silicon carbide substrate is divided at the position of the peeling layer, and the supporting substrate and the silicon carbide substrate remaining on the surface thereof are used together as a silicon carbide wafer.
[0011] In some embodiments, the specific steps of implanting dopant ions into the silicon carbide substrate to form a lift-off layer in the silicon carbide substrate include:
[0012] The doping ions are implanted into the silicon carbide substrate from the first surface of the silicon carbide substrate to form a peeling layer in the silicon carbide substrate, wherein the peeling layer separates the silicon carbide substrate into a first silicon carbide layer including the first surface and a second silicon carbide layer including the second surface, and the first silicon carbide layer and the second silicon carbide layer are distributed on opposite sides of the peeling layer along the first direction.
[0013] In some embodiments, the doping ions are hydrogen ions.
[0014] In some embodiments, the material of the support substrate includes silicon carbide, and the percentage content of silicon carbide in the support substrate is lower than the percentage content of silicon carbide in the silicon carbide substrate.
[0015] In some embodiments, the specific steps of activating the first surface of the silicon carbide substrate to form a hydrophilic bonding group on the first surface of the silicon carbide substrate include:
[0016] The first surface of the silicon carbide substrate is cleaned with ammonia water to form hydroxyl groups on the first surface of the silicon carbide substrate.
[0017] In some embodiments, the concentration of the ammonia water is 0.2% to 1.2%.
[0018] In some embodiments, the support substrate includes an upper surface and a lower surface opposite to the upper surface; the specific step of bonding the silicon carbide substrate to the surface of the support substrate with the first surface facing the support substrate further includes:
[0019] Cleaning the upper surface of the supporting substrate with ammonia water;
[0020] The silicon carbide substrate is bonded to the surface of the support substrate in a direction in which the first surface of the silicon carbide substrate faces the upper surface of the support substrate.
[0021] In some embodiments, the specific steps of dividing the silicon carbide substrate at the position of the peeling layer and using the supporting substrate and the silicon carbide substrate remaining on the surface thereof as a silicon carbide wafer include:
[0022] A first heat treatment process is performed on the silicon carbide substrate to peel off the second silicon carbide layer at the position of the peeling layer, and the support substrate and the first silicon carbide layer are used together as the silicon carbide wafer.
[0023] In some embodiments, the silicon carbide substrate is subjected to a first heat treatment process, and after the second silicon carbide layer is peeled off at the position of the peeling layer, the following steps are further included:
[0024] Implanting the doping ions into the second silicon carbide layer to form another peeling layer in the second silicon carbide layer, wherein the second silicon carbide layer includes a top surface and a bottom surface that are relatively distributed;
[0025] Activating the top surface of the second silicon carbide layer to form a hydrophilic bonding group on the top surface of the second silicon carbide layer;
[0026] Bonding the second silicon carbide layer to the surface of another supporting substrate in a direction where the top surface of the second silicon carbide layer faces the other supporting substrate;
[0027] The second silicon carbide layer is divided at the position of the peeling layer, and another supporting substrate and the second silicon carbide layer remaining on the surface thereof are used together as another silicon carbide wafer.
[0028] According to some other embodiments, the present invention further provides a silicon carbide wafer, which is formed by the method for preparing the silicon carbide wafer as described above; the silicon carbide wafer comprises:
[0029] A supporting substrate, wherein the material of the supporting substrate comprises silicon carbide;
[0030] The first silicon carbide layer is bonded to the surface of the supporting substrate, and the percentage content of silicon carbide in the supporting substrate is lower than the percentage content of silicon carbide in the first silicon carbide layer.
[0031] The silicon carbide wafer and preparation method provided by the present invention form a peeling layer by first injecting doping ions into the silicon carbide substrate, and after bonding the silicon carbide substrate to a supporting substrate, the silicon carbide substrate is split at the position of the peeling layer, and the supporting substrate and the silicon carbide substrate remaining on the surface are used together as a silicon carbide wafer. On the one hand, there is no need to implement a large number of grinding processes, which saves the preparation time and labor costs of the silicon carbide wafer and improves the preparation efficiency of the silicon carbide wafer; on the other hand, the peeled silicon carbide substrate can be recycled, that is, the silicon carbide wafer can be prepared again, which reduces the waste of the silicon carbide substrate and thus reduces the preparation cost of the silicon carbide wafer. At the same time, since the silicon carbide substrate is supported by the supporting substrate, the warping of the prepared silicon carbide wafer can be reduced, and the quality of the silicon carbide wafer is improved. Moreover, before bonding the silicon carbide substrate to the supporting substrate, the present invention activates the bonding surface (i.e., the first surface) of the silicon carbide substrate, so that a hydrophilic bonding group is formed on the first surface of the silicon carbide substrate, so that the silicon carbide substrate and the supporting substrate can be combined through a strong intermolecular force during the bonding process, thereby enhancing the bonding strength between the silicon carbide substrate and the supporting substrate and improving the structural stability of the silicon carbide wafer finally formed. BRIEF DESCRIPTION OF THE DRAWINGS
[0032] Figure 1 is a flow chart of a method for preparing a silicon carbide wafer in a specific embodiment of the present invention;
[0033] Figure 2 is a schematic structural diagram of a silicon carbide substrate in a specific embodiment of the present invention;
[0034] Figure 3 is a schematic diagram of the structure after doping ions are injected into the silicon carbide substrate in a specific embodiment of the present invention;
[0035] Figure 4 is a schematic diagram of the structure after the silicon carbide substrate and the supporting substrate are bonded in a specific embodiment of the present invention;
[0036] Figure 5 is a schematic structural diagram of a silicon carbide wafer formed in a specific embodiment of the present invention;
[0037] Figure 6 It is a schematic diagram of the structure of the second silicon carbide layer peeled off in a specific embodiment of the present invention. DETAILED DESCRIPTION
[0038] The specific implementation manner of the silicon carbide wafer and the preparation method thereof provided by the present invention is described in detail below with reference to the accompanying drawings.
[0039] This specific embodiment provides a method for preparing a silicon carbide wafer. Figure 1 FIG. 1 is a flow chart of a method for preparing a silicon carbide wafer in a specific embodiment of the present invention. Figure 1 As shown, the method for preparing the silicon carbide wafer comprises the following steps:
[0040] Step S11, providing a silicon carbide substrate, wherein the silicon carbide substrate comprises a first surface and a second surface that are oppositely distributed along a first direction;
[0041] Step S12, implanting doping ions into the silicon carbide substrate to form a peeling layer in the silicon carbide substrate;
[0042] Step S13, activating the first surface of the silicon carbide substrate to form a hydrophilic bonding group on the first surface of the silicon carbide substrate;
[0043] Step S14, bonding the silicon carbide substrate to the surface of the supporting substrate with the first surface facing the supporting substrate;
[0044] Step S15 , dividing the silicon carbide substrate at the position of the peeling layer, and using the supporting substrate and the silicon carbide substrate remaining on the surface thereof together as a silicon carbide wafer.
[0045] Figure 2 is a schematic structural diagram of a silicon carbide substrate in a specific embodiment of the present invention, Figure 3 2 is a schematic diagram of a structure after doping ions are injected into a silicon carbide substrate in a specific embodiment of the present invention. In some embodiments, the specific steps of injecting doping ions into the silicon carbide substrate 20 to form a peeling layer 30 in the silicon carbide substrate 20 include:
[0046] The doping ions are implanted into the silicon carbide substrate 20 from the first surface 201 of the silicon carbide substrate 20 to form a peeling layer 30 in the silicon carbide substrate 20. The peeling layer 30 separates the silicon carbide substrate 20 into a first silicon carbide layer 21 including the first surface 201 and a second silicon carbide layer 22 including the second surface 202. The first silicon carbide layer 21 and the second silicon carbide layer 22 are distributed on opposite sides of the peeling layer 30 along the first direction. Figure 3 shown.
[0047] Specifically, the silicon carbide substrate 20 includes a first surface 201 and a second surface 202 opposite to the first surface 201 along the first direction. In one example, the doping ions can be directly implanted into the silicon carbide substrate 20 from the first surface 201 of the silicon carbide substrate 20 along the first direction, thereby forming the peeling layer 30. The peeling layer 30 separates the silicon carbide substrate 20 into the first silicon carbide layer 21 and the second silicon carbide layer 22 distributed on opposite sides of the peeling layer 30 along the first direction. The first silicon carbide layer 21 is used to subsequently form a part of the silicon carbide wafer. When the doping ions are implanted into the silicon carbide substrate 20, the implantation dose, implantation direction, implantation depth and other parameters of the doping ions can be adjusted according to the desired thickness of the first silicon carbide layer 21. For example, when the doping ions are implanted into the silicon carbide substrate 20, the implantation dose of the doping ions is 5×10 16 Pieces / cm 2 ~8×10 16 Pieces / cm 2 , the injection energy is 75keV. In one example, the thickness of the stripping layer 30 along the first direction is uniform to improve the surface flatness of the first silicon carbide layer 21 remaining after the subsequent stripping process. In this specific embodiment, the doping ions are directly injected into the silicon carbide substrate 20 on the first surface 201 of the silicon carbide substrate 20. Before the injection, there is no need to form a protective structure such as an oxide layer on the first surface 201 of the silicon carbide substrate 20, which not only further simplifies the preparation process of the silicon carbide wafer, but also effectively reduces the preparation cost of the silicon carbide wafer.
[0048] In some embodiments, the doping ions are hydrogen ions.
[0049] Specifically, hydrogen ions are used as the doping ions to implant the silicon carbide substrate 20. On the one hand, since the mass of hydrogen ions is relatively light, the damage to the silicon carbide substrate 20 during the ion implantation process can be reduced, thereby reducing the defects in the silicon carbide substrate 20 caused by ion implantation, thereby improving the quality of the silicon carbide wafer formed subsequently; on the other hand, the hydrogen ions in the peeling layer 30 are prone to expand when heated, which not only simplifies the operation of peeling the second silicon carbide layer 22 from the silicon carbide substrate 20, but also reduces the impurity residues on the surface of the first silicon carbide layer 21 after the peeling process. In other embodiments, the doping ions can also be helium ions or the doping ions are a combination of hydrogen ions and helium ions.
[0050] In some embodiments, the material of the support substrate 40 includes silicon carbide, and the percentage content of silicon carbide in the support substrate 40 is lower than the percentage content of silicon carbide in the silicon carbide substrate 20 .
[0051] Specifically, the material of the support substrate 40 includes silicon carbide, so that the difference in thermal expansion coefficient between the support substrate 40 and the silicon carbide substrate 20 can be reduced to enhance the bonding strength between the support substrate 40 and the silicon carbide substrate 20. The percentage content of silicon carbide in the support substrate 40 can be the mass percentage of silicon carbide in the support substrate 40. The percentage content of silicon carbide in the silicon carbide substrate 20 can be the mass percentage of silicon carbide in the silicon carbide substrate 20. In one example, the support substrate 40 is a low-purity silicon carbide material substrate, and the silicon carbide substrate 20 is a high-purity silicon carbide material substrate, so as to enhance the bonding strength between the support substrate 40 and the silicon carbide substrate 20 while further reducing the preparation cost of the silicon carbide wafer.
[0052] In some embodiments, the specific steps of activating the first surface 201 of the silicon carbide substrate 20 to form a hydrophilic bonding group on the first surface 201 of the silicon carbide substrate 20 include:
[0053] The first surface 201 of the silicon carbide substrate 20 is cleaned with ammonia water to form hydroxyl groups (—OH) on the first surface 201 of the silicon carbide substrate 20 .
[0054] In some embodiments, the concentration of the ammonia water is 0.2% to 1.2%.
[0055] Figure 41 is a schematic diagram of the structure after bonding the silicon carbide substrate and the support substrate in a specific embodiment of the present invention. In some embodiments, the support substrate 40 includes an upper surface and a lower surface opposite to the upper surface; the specific steps of bonding the silicon carbide substrate 20 to the surface of the support substrate 40 with the first surface facing the support substrate 40 also include:
[0056] Cleaning the upper surface of the supporting substrate 40 with ammonia water;
[0057] The silicon carbide substrate 20 is bonded to the surface of the support substrate 40 in a direction in which the first surface 201 of the silicon carbide substrate 20 faces the upper surface of the support substrate 40 .
[0058] Specifically, the first surface 201 of the silicon carbide substrate 20 is cleaned with ammonia water to activate the first surface 201 of the silicon carbide substrate 20, so that a large number of hydroxyl groups are formed on the first surface 201 of the silicon carbide substrate 20, so that in the process of bonding the silicon carbide substrate 20 and the supporting substrate 40 in the direction of the first surface 201 of the silicon carbide substrate 20 toward the upper surface of the supporting substrate 40, the silicon carbide substrate 20 and the supporting substrate 40 can be tightly bonded through intermolecular forces, thereby increasing the bonding force between the silicon carbide substrate 20 and the supporting substrate 40 and improving the bonding strength between the silicon carbide substrate 20 and the supporting substrate 40.
[0059] Using low-concentration ammonia water (i.e., ammonia water with a concentration of 0.2% to 1.2%) to clean the first surface 201 of the silicon carbide substrate 20 can not only increase the number of the hydroxyl groups on the first surface 201 of the silicon carbide substrate 20, but also will not cause damage such as corrosion to the silicon carbide substrate 20, thereby ensuring the performance stability of the silicon carbide substrate 20. Using ammonia water to clean the upper surface of the supporting substrate 40 can further increase the intermolecular force when the silicon carbide substrate 20 is bonded to the supporting substrate 40, thereby further improving the bonding strength between the silicon carbide substrate 20 and the supporting substrate 40.
[0060] Figure 5 is a schematic diagram of the structure of a silicon carbide wafer formed in a specific embodiment of the present invention, Figure 6 3 is a schematic diagram of the structure of the second silicon carbide layer peeled off in a specific embodiment of the present invention. In some embodiments, the silicon carbide substrate 20 is split at the position of the peeling layer 30, and the specific steps of using the supporting substrate 40 and the silicon carbide substrate 20 remaining on its surface as a silicon carbide wafer include:
[0061] A first heat treatment process is performed on the silicon carbide substrate 20 to peel off the second silicon carbide layer 22 at the position of the peeling layer 30 , and the support substrate 40 and the first silicon carbide layer 21 are used together as the silicon carbide wafer.
[0062] For example, the silicon carbide substrate 20 bonded to the support substrate 40 is subjected to a first heat treatment process such as high temperature annealing, so that the hydrogen ions in the peeling layer 30 are heated and expanded to form hydrogen bubbles. The formation of hydrogen bubbles will cause stress concentration in the silicon carbide substrate 20, so that the silicon carbide substrate 20 is peeled off at the position of the peeling layer 30, and the hydrogen bubbles escape from the silicon carbide substrate 20 during the peeling process. Peeling off the second silicon carbide layer 22 at the position of the peeling layer 30 by using the first heat treatment process not only helps to improve the preparation efficiency of the silicon carbide wafer, but also can ensure the integrity of the second silicon carbide layer 22 remaining after peeling, so that the second silicon carbide layer 22 can be used again to form a silicon carbide wafer later, thereby improving the utilization rate of the silicon carbide substrate 20 and effectively reducing the preparation cost of the silicon carbide wafer. In one example, the temperature of the first heat treatment process is greater than or equal to 800°C.
[0063] In some embodiments, after a first heat treatment process is performed on the silicon carbide substrate 20 and the second silicon carbide layer 22 is peeled off at the position of the peeling layer 30, the following steps are further included:
[0064] A second heat treatment process is performed on the silicon carbide wafer.
[0065] Specifically, the second heat treatment process can be used to strengthen the bonding strength between the first silicon carbide layer 21 and the supporting substrate 40, that is, the lattice defects at the bonding interface between the first silicon carbide layer 21 and the supporting substrate 40 are repaired by the second heat treatment process, thereby further enhancing the bonding strength between the first silicon carbide layer 21 and the supporting substrate 40, and improving the structural stability of the prepared silicon carbide wafer. After the second heat treatment process is completed, the top surface of the first silicon carbide layer 21 (that is, the surface of the first silicon carbide layer 21 away from the supporting substrate 40) can also be polished to improve the flatness of the top surface of the first silicon carbide layer 21, so as to facilitate the subsequent implementation of semiconductor processes on the surface of the first silicon carbide layer 21.
[0066] In some embodiments, after a first heat treatment process is performed on the silicon carbide substrate 20 and the second silicon carbide layer 22 is peeled off at the position of the peeling layer 30, the following steps are further included:
[0067] Implanting the doping ions into the second silicon carbide layer 22 to form another peeling layer 30 in the second silicon carbide layer 22, wherein the second silicon carbide layer 22 includes a top surface and a bottom surface that are relatively distributed;
[0068] Activating the top surface of the second silicon carbide layer 22 to form a hydrophilic bonding group on the top surface of the second silicon carbide layer 22;
[0069] Bonding the second silicon carbide layer 22 to the surface of another supporting substrate 40 in a direction where the top surface of the second silicon carbide layer 22 faces the other supporting substrate 40;
[0070] The second silicon carbide layer 22 is divided at the position of the peeling layer 30 , and another supporting substrate 40 and the remaining second silicon carbide layer 22 on the surface thereof are used together as another silicon carbide wafer.
[0071] Specifically, since the second silicon carbide layer 22 is peeled off by the peeling process, the morphology of the second silicon carbide layer 22 is complete, so that the second silicon carbide layer 22 can be used again to form another silicon carbide wafer. For example, hydrogen ions are implanted into the second silicon carbide layer 22 to form another peeling layer 30 in the second silicon carbide layer 22. Afterwards, the top surface of the second silicon carbide layer 22 is activated and bonded to another supporting substrate 40 including silicon carbide material. Then, the second silicon carbide layer 22 is divided at the position of the peeling layer 30 by a high-temperature annealing process, and another supporting substrate 40 and the second silicon carbide layer 22 remaining on its surface are used together as another silicon carbide wafer.
[0072] This specific embodiment also provides a silicon carbide wafer. The silicon carbide wafer provided in this specific embodiment is formed by the silicon carbide wafer preparation method as described above. For example, the silicon carbide wafer preparation method can be referred to Figure 1-Figure 6 The structural diagram of the silicon carbide wafer provided in this specific embodiment can be found in Figure 5 .like Figure 5 As shown, the silicon carbide wafer comprises:
[0073] A supporting substrate 40, wherein the material of the supporting substrate 40 includes silicon carbide;
[0074] The first silicon carbide layer 21 is bonded to the surface of the support substrate 40 , and the percentage content of silicon carbide in the support substrate 40 is lower than the percentage content of silicon carbide in the first silicon carbide layer 21 .
[0075] The silicon carbide wafer and its preparation method provided in this specific embodiment form a peeling layer by first injecting doping ions into the silicon carbide substrate, and after bonding the silicon carbide substrate to a supporting substrate, the silicon carbide substrate is split at the position of the peeling layer, and the supporting substrate and the silicon carbide substrate remaining on its surface are used together as a silicon carbide wafer. On the one hand, there is no need to implement a large number of grinding processes, which saves the preparation time and labor costs of the silicon carbide wafer and improves the preparation efficiency of the silicon carbide wafer; on the other hand, the peeled silicon carbide substrate can be recycled, that is, the silicon carbide wafer can be prepared again, which reduces the waste of the silicon carbide substrate and thus reduces the preparation cost of the silicon carbide wafer. At the same time, since the silicon carbide substrate is supported by the supporting substrate, the warping of the prepared silicon carbide wafer can be reduced, thereby improving the quality of the silicon carbide wafer. Moreover, before bonding the silicon carbide substrate to the supporting substrate, the present specific embodiment performs an activation treatment on the bonding surface (i.e., the first surface) of the silicon carbide substrate, so that a hydrophilic bonding group is formed on the first surface of the silicon carbide substrate, so that the silicon carbide substrate and the supporting substrate can be combined through strong intermolecular forces during the bonding process, thereby enhancing the bonding strength between the silicon carbide substrate and the supporting substrate and improving the structural stability of the silicon carbide wafer finally formed.
[0076] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.
Claims
1. A method for preparing a silicon carbide wafer, characterized in that: The steps include: Providing a silicon carbide substrate, the silicon carbide substrate comprising a first surface and a second surface oppositely distributed along a first direction; Implanting doping ions into the silicon carbide substrate to form a peeling layer in the silicon carbide substrate; Activating the first surface of the silicon carbide substrate to form a hydrophilic bonding group on the first surface of the silicon carbide substrate; Bonding the silicon carbide substrate to the surface of the supporting substrate with the first surface facing the supporting substrate; The silicon carbide substrate is divided at the position of the peeling layer, and the supporting substrate and the silicon carbide substrate remaining on the surface thereof are used together as a silicon carbide wafer.
2. The method for preparing a silicon carbide wafer according to claim 1, characterized in that: The specific steps of injecting dopant ions into the silicon carbide substrate to form a stripping layer in the silicon carbide substrate include: injecting the dopant ions into the silicon carbide substrate from the first surface of the silicon carbide substrate to form a stripping layer in the silicon carbide substrate, the stripping layer separating the silicon carbide substrate into a first silicon carbide layer including the first surface and a second silicon carbide layer including the second surface, the first silicon carbide layer and the second silicon carbide layer being distributed on opposite sides of the stripping layer along the first direction.
3. The method for preparing a silicon carbide wafer according to claim 1, characterized in that: The doping ions are hydrogen ions.
4. The method for preparing a silicon carbide wafer according to claim 1, characterized in that: The material of the support substrate includes silicon carbide, and the percentage content of silicon carbide in the support substrate is lower than the percentage content of silicon carbide in the silicon carbide substrate.
5. The method for preparing a silicon carbide wafer according to claim 4, characterized in that: The specific steps of activating the first surface of the silicon carbide substrate to form a hydrophilic bonding group on the first surface of the silicon carbide substrate include: The first surface of the silicon carbide substrate is cleaned with ammonia water to form hydroxyl groups on the first surface of the silicon carbide substrate.
6. The method for preparing a silicon carbide wafer according to claim 5, characterized in that: The concentration of the ammonia water is 0.2% to 1.2%.
7. The method for preparing a silicon carbide wafer according to claim 5, characterized in that: The support substrate comprises an upper surface and a lower surface opposite to the upper surface; the specific step of bonding the silicon carbide substrate to the surface of the support substrate with the first surface facing the support substrate further comprises: Cleaning the upper surface of the supporting substrate with ammonia water; The silicon carbide substrate is bonded to the surface of the support substrate in a direction in which the first surface of the silicon carbide substrate faces the upper surface of the support substrate.
8. The method for preparing a silicon carbide wafer according to claim 4, characterized in that: The specific steps of dividing the silicon carbide substrate at the position of the peeling layer and using the supporting substrate and the silicon carbide substrate remaining on the surface thereof as a silicon carbide wafer include: A first heat treatment process is performed on the silicon carbide substrate to peel off the second silicon carbide layer at the position of the peeling layer, and the support substrate and the first silicon carbide layer are used together as the silicon carbide wafer.
9. The method for preparing a silicon carbide wafer according to claim 8, characterized in that: The first heat treatment process is performed on the silicon carbide substrate, and after the second silicon carbide layer is peeled off at the position of the peeling layer, the following steps are also included: Implanting the doping ions into the second silicon carbide layer to form another peeling layer in the second silicon carbide layer, wherein the second silicon carbide layer includes a top surface and a bottom surface that are relatively distributed; Activating the top surface of the second silicon carbide layer to form a hydrophilic bonding group on the top surface of the second silicon carbide layer; Bonding the second silicon carbide layer to the surface of another supporting substrate in a direction where the top surface of the second silicon carbide layer faces the other supporting substrate; The second silicon carbide layer is divided at the position of the peeling layer, and another supporting substrate and the second silicon carbide layer remaining on the surface thereof are used together as another silicon carbide wafer.
10. A silicon carbide wafer, characterized in that: The silicon carbide wafer is formed by the method for preparing the silicon carbide wafer according to claim 1; the silicon carbide wafer comprises: A supporting substrate, wherein the material of the supporting substrate comprises silicon carbide; The first silicon carbide layer is bonded to the surface of the supporting substrate, and the percentage content of silicon carbide in the supporting substrate is lower than the percentage content of silicon carbide in the first silicon carbide layer.