Silicon carbide wafer and preparation method thereof
By injecting doped ions into the silicon carbide substrate to form a peeling layer and bonding the support substrate, the problems of low efficiency and high cost of silicon carbide wafer preparation are solved, and efficient and low-cost silicon carbide wafer preparation is achieved, improving wafer quality.
Patent Information
- Application Number
- CN202510281456.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-11
- Publication Date
- 2025-07-04
AI Technical Summary
In the prior art, the preparation of silicon carbide wafers is time-consuming and labor-intensive, low efficiency and high cost, and the grinding process leads to waste of materials.
The release layer is formed by injecting dopant ions into the silicon carbide substrate, and bonding the silicon carbide substrate to the support substrate, and the substrate is divided at the release layer position to form a silicon carbide wafer, reducing the grinding process, and recycling the peeled silicon carbide substrate.
Improves the preparation efficiency of silicon carbide wafers, reduces costs, and improves wafer quality, reducing warpage and impurity residues.
Smart Images
Figure CN120261336A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of semiconductor manufacturing, and particularly to a silicon carbide wafer and a preparation method thereof. Background Art
[0002] Due to the advantages of stable chemical properties, high thermal conductivity, small thermal expansion coefficient, good wear resistance, etc., silicon carbide materials are increasingly widely used as substrate wafers for high-temperature, high-voltage, and high-power electronic devices. 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 with a required thickness by grinding off a part of the thickness of the silicon carbide substrate. However, this method of preparing silicon carbide wafers by grinding not only takes time and effort, resulting in low preparation efficiency of silicon carbide wafers, but also causes waste of silicon carbide materials and increases 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 is a technical problem that needs to be solved urgently at present. 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 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.
[0005] According to some embodiments, the present invention provides a method for preparing a silicon carbide wafer, including the following steps:
[0006] Provide a silicon carbide substrate, the silicon carbide substrate including a first surface and a second surface oppositely distributed along a first direction;
[0007] Inject doping ions into the silicon carbide substrate to form a peeling layer in the silicon carbide substrate, and the injection direction of the doping ions intersects obliquely with the first surface;
[0008] Bond the silicon carbide substrate to the surface of the support substrate with the first surface facing the support substrate;
[0009] Divide the silicon carbide substrate at the position of the peeling layer, and use the support substrate and the remaining silicon carbide substrate on its surface together as a silicon carbide wafer.
[0010] In some embodiments, the specific steps of injecting doping ions into the silicon carbide substrate to form a peeling layer in the silicon carbide substrate include:
[0011] Inject the doping ions into the silicon carbide substrate from the first surface thereof to form a separation layer within the silicon carbide substrate, the separation 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 separation layer along the first direction.
[0012] In some embodiments, the doping ions are any one of hydrogen ions and helium ions or a combination of both.
[0013] In some embodiments, the implantation energy for implanting the doping ions into the silicon carbide substrate is 50 keV to 220 keV, and the implantation dose is 5×10 16 ions / cm 2 ~1×10 17 ions / cm 2 .
[0014] In some embodiments, the tilt angle of the implantation direction for implanting the doping ions into the silicon carbide substrate is 5° to 15°, and the twist angle of the implantation direction for implanting the doping ions into the silicon carbide substrate is 0° to 5°.
[0015] 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.
[0016] In some embodiments, the specific steps of bonding the silicon carbide substrate to the surface of the support substrate with the first surface facing the support substrate include:
[0017] Activating the first surface of the silicon carbide substrate to form hydrophilic bonding groups on the first surface of the silicon carbide substrate;
[0018] Bonding the silicon carbide substrate to the surface of the support substrate with the first surface facing the support substrate.
[0019] In some embodiments, the specific steps of dividing the silicon carbide substrate at the position of the separation layer and using the support substrate and the remaining silicon carbide substrate on its surface as a silicon carbide wafer together include:
[0020] Performing a first heat treatment process on the silicon carbide substrate to strip the second silicon carbide layer at the position of the separation layer, and using the support substrate and the first silicon carbide layer together as the silicon carbide wafer.
[0021] In some embodiments, after performing a first heat treatment process on the silicon carbide substrate and stripping the second silicon carbide layer at the position of the separation layer, the following steps are further included:
[0022] Inject the doping ions into the second silicon carbide layer in a direction that intersects obliquely with the top surface of the second silicon carbide layer to form another release layer within the second silicon carbide layer, where the second silicon carbide layer includes the top surface and the bottom surface that are oppositely distributed along the first direction;
[0023] Bond the second silicon carbide layer to the surface of another support substrate with the top surface of the second silicon carbide layer facing the direction of another support substrate;
[0024] Divide the second silicon carbide layer at the position of the release layer within the second silicon carbide layer, and use another support substrate and the remaining second silicon carbide layer on its surface together as another silicon carbide wafer.
[0025] According to some other embodiments, the present invention further provides a silicon carbide wafer formed by using the preparation method of the silicon carbide wafer as described above; the silicon carbide wafer includes:
[0026] A support substrate, the material of the support substrate includes silicon carbide;
[0027] A first silicon carbide layer, bonded to the surface of the support substrate, and the percentage content of silicon carbide in the support substrate is lower than the percentage content of silicon carbide in the first silicon carbide layer.
[0028] For the silicon carbide wafer and its preparation method provided by the present invention, by first injecting doping ions into the silicon carbide substrate to form a release layer, after bonding the silicon carbide substrate to a support substrate, dividing the silicon carbide substrate at the position of the release layer, and using a support substrate and the remaining silicon carbide substrate on its surface together as a silicon carbide wafer. On the one hand, there is no need to implement a large number of grinding processes, saving the preparation time and labor cost of the silicon carbide wafer and improving the preparation efficiency of the silicon carbide wafer; on the other hand, the peeled silicon carbide substrate can be recycled, that is, used to prepare silicon carbide wafers again, reducing the waste of the silicon carbide substrate, thereby reducing the preparation cost of the silicon carbide wafer. At the same time, since the silicon carbide substrate is supported by the support substrate, the warpage of the prepared silicon carbide wafer can be reduced, improving the quality of the silicon carbide wafer. Moreover, the direction in which the doping ions are injected into the silicon carbide substrate intersects obliquely with the first surface of the silicon carbide substrate, that is, the included angle between the injection direction and the normal line of the silicon carbide substrate is an acute angle, thereby reducing the channeling effect of ion implantation, improving the uniformity of the distribution of the release layer within the silicon carbide substrate, and further improving the quality of the silicon carbide wafer. Description of the Drawings
[0029] Figure 1 is a flowchart of the preparation method of the silicon carbide wafer in the specific embodiment of the present invention;
[0030] Figure 2 It is a schematic structural diagram of a silicon carbide substrate in a specific embodiment of the present invention;
[0031] Figure 3 It is a schematic structural diagram after doping ions are implanted into the silicon carbide substrate in a specific embodiment of the present invention;
[0032] Figure 4 It is a schematic diagram of the implantation direction of doping ions in a specific embodiment of the present invention;
[0033] Figure 5 It is a schematic structural diagram after bonding the silicon carbide substrate and the support substrate in a specific embodiment of the present invention;
[0034] Figure 6 It is a schematic structural diagram of the formed silicon carbide wafer in a specific embodiment of the present invention;
[0035] Figure 7 It is a schematic structural diagram of the second silicon carbide layer peeled off in a specific embodiment of the present invention. Specific Embodiment
[0036] The following will make a detailed description of the specific embodiment of the silicon carbide wafer and its manufacturing method provided by the present invention with reference to the accompanying drawings.
[0037] This specific embodiment provides a method for manufacturing a silicon carbide wafer, Figure 1 It is a flowchart of the method for manufacturing a silicon carbide wafer in a specific embodiment of the present invention. As Figure 1 shown, the method for manufacturing the silicon carbide wafer includes the following steps:
[0038] Step S11, providing a silicon carbide substrate, the silicon carbide substrate includes a first surface and a second surface that are oppositely distributed along a first direction;
[0039] Step S12, implanting doping ions into the silicon carbide substrate to form a peeling layer in the silicon carbide substrate, and the implantation direction of the doping ions intersects obliquely with the first surface;
[0040] Step S13, bonding the silicon carbide substrate to the surface of the support substrate with the first surface facing the support substrate;
[0041] Step S14, dividing the silicon carbide substrate at the position of the peeling layer, and using one of the support substrates and the remaining silicon carbide substrate on its surface as a silicon carbide wafer together.
[0042] Figure 2 It is a schematic structural diagram of a silicon carbide substrate in a specific embodiment of the present invention, Figure 3It is a schematic structural diagram after doping ions are implanted into a silicon carbide substrate in a specific embodiment of the present invention. In some embodiments, as Figure 2 and Figure 3 shown, the specific steps of implanting doping ions into the silicon carbide substrate 20 to form a separation layer 30 in the silicon carbide substrate 20 include:
[0043] Implant the doping ions into the silicon carbide substrate 20 from the first surface 201 of the silicon carbide substrate 20 to form a separation layer 30 in the silicon carbide substrate 20. The separation layer 30 divides 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 separation layer 30 along the first direction.
[0044] Specifically, the silicon carbide substrate 20 includes the first surface 201 and the second surface 202 opposite to the first surface 201 along the first direction. In an 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, so as to form the separation layer 30. The separation layer 30 divides 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 separation layer 30 along the first direction. Among them, the first silicon carbide layer 21 is used to form a part of the silicon carbide wafer subsequently. In this specific embodiment, the doping ions are directly implanted into the silicon carbide substrate 20 from the first surface 201 of the silicon carbide substrate 20, and 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 before implantation, 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.
[0045] In some embodiments, the doping ions are any one of hydrogen ions and helium ions or a combination of the two.
[0046] For example, the hydrogen ions are protium (1H), deuterium (2H), or tritium (3H). By using hydrogen ions or helium ions as the doping ions to implant into the silicon carbide substrate 20, on the one hand, since the masses of hydrogen ions and helium ions are relatively light, during the ion implantation process, the damage to the silicon carbide substrate 20 can be reduced, thereby reducing the defects generated in the silicon carbide substrate 20 due to ion implantation, and improving the quality of the subsequent formed silicon carbide wafer; on the other hand, the hydrogen ions and helium ions in the stripping layer 30 are prone to expand when heated, which not only simplifies the operation of stripping 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 stripping process.
[0047] In some embodiments, the implantation energy for implanting doping ions into the silicon carbide substrate is 50 keV to 220 keV, and the implantation dose is 5×10 16 ions / cm 2 ~1×10 17 ions / cm 2 .
[0048] For example, during the formation of the stripping layer 30, the implantation energy for implanting doping ions into the silicon carbide substrate is 50 keV to 220 keV, and the implantation dose is 5×10 16 ions / cm 2 ~1×10 17 ions / cm 2 , and the implantation temperature is room temperature (for example, 20°C to 25°C), so that the formed stripping layer 30 can sufficiently isolate the first silicon carbide layer 21 and the second silicon carbide layer 22, and further enable the subsequent sufficient separation of the first silicon carbide layer 21 and the second silicon carbide layer 22 through the stripping layer 30, while avoiding affecting the performance of the first silicon carbide layer 21 and the second silicon carbide layer 22.
[0049] Figure 4 is a schematic diagram of the implantation direction of doping ions in the specific embodiment of the present invention. In some embodiments, as Figure 4 shown, the inclination angle ti of the implantation direction for implanting doping ions into the silicon carbide substrate 20 is 5° to 15°, and the twist angle tw of the implantation direction for implanting doping ions into the silicon carbide substrate is 0° to 5°.
[0050] Specifically, Figure 4 the implantation direction OB in (a) of Figure 4 wherein the doping ions are implanted into the interior of the silicon carbide substrate from the first surface 201 and the angle ti between the normal line of the silicon carbide substrate ( Figure 4As shown in (b) therein, the included angle tw between the projection OA of the implantation direction OB of the doped ions implanted from the first surface 201 into the interior of the silicon carbide substrate on the first surface 201 and the connection line OC between the center of the silicon carbide substrate and the notch on the silicon carbide substrate is 0° to 5°. In this specific embodiment, by setting the tilt angle ti to 5° to 15° and setting the twist angle tw to 0° to 5°, the influence of channeling effect during the doped ion implantation process can be reduced, so that the thickness of the formed peeling layer 30 is evenly distributed, the surface flatness of the remaining first silicon carbide layer 21 after the subsequent peeling process is improved, and the surface flatness of the formed silicon carbide wafer is ensured.
[0051] Figure 5 FIG. is a schematic structural diagram after bonding the silicon carbide substrate and the support substrate in a specific embodiment of the present invention. 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.
[0052] Specifically, the material of the support substrate 40 includes silicon carbide, so as to reduce the difference in thermal expansion coefficient between the support substrate 40 and the silicon carbide substrate 20, and enhance the bonding strength between the support substrate 40 and the silicon carbide substrate 20. Among them, the percentage content of silicon carbide in the support substrate 40 may be the mass percentage of silicon carbide in the support substrate 40. The percentage content of silicon carbide in the silicon carbide substrate 20 may 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 further reduce the preparation cost of the silicon carbide wafer while enhancing the bonding strength between the support substrate 40 and the silicon carbide substrate 20.
[0053] In some embodiments, the specific steps of bonding the silicon carbide substrate 20 to the surface of the support substrate 40 with the first surface 201 facing the support substrate 40 include:
[0054] Activating the first surface 201 of the silicon carbide substrate 20 to form hydrophilic bonding groups on the first surface 201 of the silicon carbide substrate 20;
[0055] Bonding the silicon carbide substrate 20 to the surface of the support substrate 40 with the first surface 201 facing the support substrate 40.
[0056] For example, 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. Therefore, in the process of bonding the silicon carbide substrate 20 and the support substrate 40 with the first surface 201 of the silicon carbide substrate 20 facing the upper surface of the support substrate 40, close bonding between the silicon carbide substrate 20 and the support substrate 40 can be achieved through intermolecular forces, thereby increasing the bonding force between the silicon carbide substrate 20 and the support substrate 40 and improving the bonding strength between the silicon carbide substrate 20 and the support substrate 40.
[0057] Cleaning the first surface 201 of the silicon carbide substrate 20 with low-concentration ammonia water (i.e., ammonia water with a concentration of 0.2% to 1.2%) can not only increase the number of hydroxyl groups on the first surface 201 of the silicon carbide substrate 20, but also will not cause corrosion or other damage to the silicon carbide substrate 20, ensuring the performance stability of the silicon carbide substrate 20. Cleaning the upper surface of the support substrate 40 with ammonia water can further increase the intermolecular force when the silicon carbide substrate 20 and the support substrate 40 are bonded, thereby further improving the bonding strength between the silicon carbide substrate 20 and the support substrate 40.
[0058] Figure 6 It is a schematic structural diagram of a silicon carbide wafer formed in a specific embodiment of the present invention. In some embodiments, the specific steps of dividing the silicon carbide substrate 20 at the position of the release layer 30 and using a support substrate 40 and the remaining silicon carbide substrate 20 on its surface as a silicon carbide wafer together include:
[0059] The 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 release layer 30, and a support substrate 40 and the first silicon carbide layer 21 are used together as the silicon carbide wafer.
[0060] For example, a first heat treatment process such as a high-temperature annealing treatment is performed on the silicon carbide substrate 20 bonded to the support substrate 40, so that hydrogen ions or helium ions in the release layer 30 expand due to heat to form bubbles. The formation of the bubbles will cause stress concentration in the silicon carbide substrate 20, so that the silicon carbide substrate 20 peels off at the position of the release layer 30, and the bubbles escape from the silicon carbide substrate 20 during the peeling process. Using the first heat treatment process to peel off the second silicon carbide layer 22 at the position of the release layer 30 not only helps to improve the preparation efficiency of the silicon carbide wafer, but also ensures the integrity of the remaining second silicon carbide layer 22 after peeling, enabling the subsequent reuse of the second silicon carbide layer 22 to form a silicon carbide wafer, 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.
[0061] After performing the first heat treatment process on the silicon carbide substrate 20 and peeling off the second silicon carbide layer 22 at the position of the release layer 30, a second heat treatment process can be used to strengthen the bonding strength between the first silicon carbide layer 21 and the support substrate 40, that is, to repair the lattice defects at the bonding interface between the first silicon carbide layer 21 and the support substrate 40 through the second heat treatment process, thereby further enhancing the bonding strength between the first silicon carbide layer 21 and the support 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 (i.e., the surface of the first silicon carbide layer 21 facing away from the support substrate 40) can also be polished to improve the flatness of the top surface of the first silicon carbide layer 21, facilitating the subsequent implementation of semiconductor processes on the surface of the first silicon carbide layer 21.
[0062] Figure 7 It is a schematic structural diagram of the second silicon carbide layer peeled off in the specific embodiment of the present invention. In some embodiments, after performing the first heat treatment process on the silicon carbide substrate 20 and peeling off the second silicon carbide layer 22 at the position of the release layer 30, the following steps are further included:
[0063] Inject the doping ions into the second silicon carbide layer 22 along a direction that intersects obliquely with the top surface of the second silicon carbide layer 22 to form another release layer 30 in the second silicon carbide layer 22. The second silicon carbide layer 22 includes the top surface and the bottom surface that are oppositely distributed along the first direction;
[0064] Bond the second silicon carbide layer 22 to the surface of another support substrate 40 with the top surface of the second silicon carbide layer 22 facing the direction of another support substrate 40;
[0065] At the position of the release layer 30 within the second silicon carbide layer 22, the second silicon carbide layer 22 is divided, and the other support substrate 40 and the remaining second silicon carbide layer 22 on its surface are jointly used as another silicon carbide wafer.
[0066] Specifically, since the second silicon carbide layer 22 is peeled off by a peeling process, the morphology of the second silicon carbide layer 22 is complete, so that the second silicon carbide layer 22 can be reused to form another silicon carbide wafer. For example, hydrogen ions are implanted into the second silicon carbide layer 22 to form another release layer 30 within the second silicon carbide layer 22. Then, the second silicon carbide layer 22 is bonded to another support substrate 40 including silicon carbide material. Next, the second silicon carbide layer 22 is divided at the position of the release layer 30 by a high-temperature annealing process, and the other support substrate 40 and the remaining second silicon carbide layer 22 on its surface are jointly used as another silicon carbide wafer.
[0067] This specific embodiment also provides a silicon carbide wafer, which is formed by using the preparation method of the silicon carbide wafer as described above. See Figures 1 - 7 .. The schematic structural diagram of the silicon carbide wafer is shown in Figure 7 . As Figures 1 - 7 shown, the silicon carbide wafer includes:
[0068] A support substrate 40, the material of the support substrate 40 includes silicon carbide;
[0069] A first silicon carbide layer 21, 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.
[0070] The silicon carbide wafer and its preparation method provided by this specific embodiment form a peeling layer by first injecting doping ions into the silicon carbide substrate. After bonding the silicon carbide substrate to a support substrate, the silicon carbide substrate is divided at the position of the peeling layer, and the support substrate and the remaining silicon carbide substrate on its surface are used together as a silicon carbide wafer. On the one hand, a large number of grinding processes do not need to be implemented, saving the preparation time and labor cost of the silicon carbide wafer and improving the preparation efficiency of the silicon carbide wafer; on the other hand, the peeled silicon carbide substrate can be recycled, that is, used to prepare silicon carbide wafers again, reducing the waste of the silicon carbide substrate, thereby reducing the preparation cost of the silicon carbide wafer. At the same time, since the silicon carbide substrate is supported by the support substrate, the warpage of the prepared silicon carbide wafer can be reduced, improving the quality of the silicon carbide wafer. Moreover, in this specific embodiment, the direction of injecting the doping ions into the silicon carbide substrate intersects obliquely with the first surface of the silicon carbide substrate, that is, the included angle between the injection direction and the normal line of the silicon carbide substrate is an acute angle, thereby reducing the channeling effect of ion implantation, improving the uniformity of the distribution of the peeling layer in the silicon carbide substrate, and further improving the quality of the silicon carbide wafer.
[0071] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can still be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.
Claims
1. A method for preparing a silicon carbide wafer, characterized in that, It includes the following steps: Provide a silicon carbide substrate, the silicon carbide substrate including a first surface and a second surface that are oppositely distributed in a first direction; Inject doping ions into the silicon carbide substrate to form a peeling layer within the silicon carbide substrate, the injection direction of the doping ions intersecting the first surface obliquely; Bond the silicon carbide substrate to the surface of the support substrate with the first surface facing the support substrate; Divide the silicon carbide substrate at the position of the peeling layer, and use the support substrate and the remaining silicon carbide substrate on its surface together as a silicon carbide wafer.
2. The preparation method of the silicon carbide wafer according to claim 1, characterized in that, The specific steps of injecting doping ions into the silicon carbide substrate to form a peeling layer within the silicon carbide substrate include: injecting the doping ions into the silicon carbide substrate from the first surface of the silicon carbide substrate to form a peeling layer within the silicon carbide substrate, the peeling 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 peeling layer along the first direction.
3. The method for preparing a silicon carbide wafer according to claim 1, wherein The doping ions are any one of hydrogen ions and helium ions or a combination of the two.
4. The method for preparing a silicon carbide wafer according to claim 1, wherein The implantation energy for implanting doped ions into the silicon carbide substrate is 50 keV to 220 keV, and the implantation dose is 5×10 16 ions / cm 2 ~1×10 17 ions / cm 2 .
5. The method for preparing a silicon carbide wafer according to claim 1, wherein, The inclination angle of the injection direction of injecting doping ions into the silicon carbide substrate is 5° to 15°, and the torsion angle of the injection direction of injecting doping ions into the silicon carbide substrate is 0° to 5°.
6. 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.
7. The method for preparing a silicon carbide wafer according to claim 6, wherein, The specific steps of bonding the silicon carbide substrate to the surface of the support substrate with the first surface facing the support substrate include: Activating the first surface of the silicon carbide substrate to form hydrophilic bonding groups on the first surface of the silicon carbide substrate; Bonding the silicon carbide substrate to the surface of the support substrate with the first surface facing the support substrate.
8. The method for preparing a silicon carbide wafer according to claim 6, wherein, The specific steps of dividing the silicon carbide substrate at the position of the peeling layer and using the support substrate and the remaining silicon carbide substrate on its surface together as a silicon carbide wafer include: Performing a first heat treatment process on the silicon carbide substrate to peel off the second silicon carbide layer at the position of the peeling layer, and using the support substrate and the first silicon carbide layer together as the silicon carbide wafer.
9. The method for preparing a silicon carbide wafer according to claim 8, wherein After performing the first heat treatment process on the silicon carbide substrate and peeling off the second silicon carbide layer at the position of the peeling layer, it further includes the following steps: Injecting the doping ions into the second silicon carbide layer in a direction intersecting obliquely with the top surface of the second silicon carbide layer to form another peeling layer within the second silicon carbide layer, the second silicon carbide layer including a top surface and a bottom surface that are oppositely distributed in the first direction; Bonding the second silicon carbide layer to the surface of another support substrate with the top surface of the second silicon carbide layer facing the other support substrate; Dividing the second silicon carbide layer at the position of the peeling layer within the second silicon carbide layer, and using the other support substrate and the remaining second silicon carbide layer on its surface together as another silicon carbide wafer.
10. A silicon carbide wafer, characterized in that, Formed by using the method for preparing a silicon carbide wafer as described in claim 1; the silicon carbide wafer includes: A support substrate, the material of the support substrate including silicon carbide; A first silicon carbide layer, bonded to the surface of the support substrate, and the percentage content of silicon carbide in the support substrate is lower than the percentage content of silicon carbide in the first silicon carbide layer.