A method for producing a semi-insulating silicon carbide substrate

Abstract

The application relates to the technical field of semiconductor materials, in particular to a preparation method of a semi-insulating silicon carbide substrate, which comprises the following steps: mixing high-purity silicon powder and carbon powder according to a preset ratio to synthesize silicon carbide particles; performing crystal growth to obtain a silicon carbide crystal ingot; cutting, grinding and polishing the silicon carbide crystal ingot to obtain a silicon carbide single crystal substrate; and performing high-temperature annealing and impurity removal treatment on the silicon carbide single crystal substrate to obtain a high-purity semi-insulating silicon carbide substrate. In the cutting process, the following steps are included: cutting after pre-annealing treatment is performed on the silicon carbide crystal ingot; collecting contact pressure data, temperature data, cutting speed data, cooling liquid flow and integrity data in the cutting process, and then determining the optimal contact pressure and the optimal cutting temperature, so as to determine the adjustment mode of the cutting parameters. The application effectively improves the cutting quality and shortens the cutting time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor materials, and particularly relates to a preparation method of a semi-insulating silicon carbide substrate. BACKGROUND

[0002] The semi-insulating silicon carbide substrate has high resistivity, high thermal conductivity and wide band gap, can prevent current leakage in the substrate, withstand harsh environments such as high temperature and high pressure, and ensure the stability and reliability of the device. The semi-insulating silicon carbide substrate is often used in the optoelectronic field and the fields of 5G communication and national defense.

[0003] In the prior art, the semi-insulating silicon carbide substrate is often prepared by cutting the silicon carbide ingot. Due to the high brittleness of the silicon carbide ingot, the silicon carbide substrate is prone to cracking during the cutting process, and the cutting time is long. Therefore, in order to reduce the cracking risk and shorten the cutting time, the cutting parameters can be accurately controlled to ensure the stability and uniformity of the cutting process and the quality and performance of the final product.

[0004] Therefore, the present application provides a preparation method of a semi-insulating silicon carbide substrate to solve the problems of easy cracking of the silicon carbide substrate during the cutting process and long cutting time. SUMMARY

[0005] Therefore, the present application provides a preparation method of a semi-insulating silicon carbide substrate to solve the problems of easy cracking of the silicon carbide substrate during the cutting process and long cutting time.

[0006] To achieve the above-mentioned purpose, the present application provides a preparation method of a semi-insulating silicon carbide substrate, comprising:

[0007] Step S1, mixing high-purity silicon powder and carbon powder according to a preset ratio to synthesize silicon carbide particles;

[0008] Step S2, loading the silicon carbide particles into a crucible and moving to a crystal growth device for crystal growth to obtain a silicon carbide ingot;

[0009] Step S3, cutting, grinding and polishing the silicon carbide ingot to obtain a silicon carbide single crystal substrate;

[0010] Step S4, high-temperature annealing and impurity removal treatment of the silicon carbide single crystal substrate to obtain a high-purity semi-insulating silicon carbide substrate;

[0011] During the cutting process, the method comprises:

[0012] Step S31, pre-annealing treatment of the silicon carbide ingot, and cutting the silicon carbide ingot;

[0013] Step S32, collecting the contact pressure data between the cutting tool and the silicon carbide ingot, the temperature data of the cutting area, the cutting speed data, the cooling liquid flow and the integrity data of several wafers after cutting, the integrity data including the number of cracks and the kerf width;

[0014] Step S33, determining the optimal contact pressure according to the contact pressure data and the integrity data, and determining the optimal cutting temperature according to the temperature data and the integrity data;

[0015] Step S34, determining the adjustment mode of the cutting parameters according to the optimal contact pressure and the optimal cutting temperature;

[0016] Step S35, cutting the silicon carbide ingot according to the adjusted cutting parameters.

[0017] Further, in step S31, comprising:

[0018] determining the annealing temperature and the annealing time according to the residual stress inside the silicon carbide ingot;

[0019] pre-annealing the silicon carbide ingot according to the annealing temperature and the annealing time.

[0020] Further, collecting the X-ray diffraction pattern of the silicon carbide ingot, determining diffraction data according to the X-ray diffraction pattern, and determining the residual stress according to the diffraction data, the diffraction data including diffraction peak position and intensity change.

[0021] Further, determining the annealing time according to the annealing temperature and the residual stress.

[0022] Further, in step S33, determining the optimal contact pressure according to the contact pressure data and the integrity data, comprising:

[0023] determining a pressure-crack function between the crack data and the contact pressure data according to the crack data and the contact pressure data;

[0024] determining a pressure-kerf function between the kerf width and the contact pressure data according to the kerf width and the contact pressure data;

[0025] determining the optimal contact pressure according to the first weight, the pressure-crack function, the second weight, and the pressure-kerf function.

[0026] Further, in step S33, determining the optimal cutting temperature according to the temperature data and the integrity data, comprising:

[0027] determining a temperature-crack function between the crack data and the temperature data according to the crack data and the temperature data;

[0028] determining a temperature-crack function between the crack width and the temperature data according to the crack width and the temperature data;

[0029] constructing a second comprehensive optimization objective function according to the third weight, the temperature-crack function, the fourth weight and the temperature-crack function to determine the optimal cutting temperature.

[0030] Further, in step S4, the adjustment mode of the cutting parameters is determined, including:

[0031] If the pressure data is greater than or less than the optimal contact pressure, the cutting speed between the cutting tool and the silicon carbide crystal ingot is adjusted.

[0032] Further, the adjustment amount of the cutting speed is determined, including:

[0033] determining a first correlation coefficient according to the pressure data and the cutting speed data;

[0034] determining a pressure difference value according to the pressure data and the optimal contact pressure;

[0035] determining the adjustment amount of the cutting speed according to the pressure difference value and the first correlation coefficient.

[0036] Further, in step S4, the adjustment mode of the cutting parameters is determined, including:

[0037] If the temperature data is greater than or less than the optimal cutting temperature, the cooling liquid flow rate in the cutting process is adjusted.

[0038] Further, the adjustment amount of the cooling liquid flow rate is determined, including:

[0039] determining a second correlation coefficient according to the cooling liquid flow rate and the temperature data;

[0040] determining a temperature difference value according to the temperature data and the optimal cutting temperature;

[0041] determining the adjustment amount of the cooling liquid flow rate according to the temperature difference value and the second correlation coefficient.

[0042] Compared with the prior art, the beneficial effects of the present application are that, by pre-annealing the silicon carbide crystal ingot and accurately collecting multiple key data in the cutting process, the optimal cutting parameters (including the contact pressure and the cutting temperature) can be accurately determined, so as to optimize the cutting process, improve the cutting quality and integrity of the silicon carbide single crystal substrate, reduce the problems of cracks and excessive cutting, and ensure the preparation efficiency and quality of the final product.

[0043] Further, the present application pre-anneals the silicon carbide ingot before cutting, determines the annealing time and annealing temperature according to the residual stress in the silicon carbide ingot, thereby further releasing the residual stress in the silicon carbide ingot, reducing the breakage rate in the cutting process, improving the cutting quality and integrity of the silicon carbide single crystal substrate, reducing the problems of cracks and excessively large cuts, and ensuring the preparation efficiency and quality of the final product.

[0044] Further, the present application determines the optimal contact pressure according to the contact pressure data and integrity data, determines the optimal cutting temperature according to the temperature data and integrity data, thereby further optimizing the cutting parameters, improving the cutting quality and integrity of the silicon carbide single crystal substrate, reducing the problems of cracks and excessively large cuts, and ensuring the preparation efficiency and quality of the final product.

[0045] Further, the present application adjusts the cutting speed between the cutting tool and the silicon carbide ingot according to the comparison result of the pressure data and the optimal contact pressure, thereby ensuring the contact pressure between the cutting tool and the silicon carbide ingot, optimizing the cutting process, improving the cutting quality and integrity of the silicon carbide single crystal substrate, reducing the problems of cracks and excessively large cuts, and ensuring the preparation efficiency and quality of the final product.

[0046] Further, the present application adjusts the cooling liquid flow when the cutting tool cuts the silicon carbide ingot according to the comparison result of the temperature data and the optimal cutting temperature, thereby preventing thermal deformation and thermal damage of the silicon carbide ingot caused by excessively high temperature, optimizing the cutting process, improving the cutting quality and integrity of the silicon carbide single crystal substrate, reducing the problems of cracks and excessively large cuts, and ensuring the preparation efficiency and quality of the final product. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 The flowchart of the preparation method of the semi-insulating silicon carbide substrate of the embodiment of the present application is shown in the figure.

[0048] Figure 2 The flowchart of determining the adjustment mode of the cutting parameters of the embodiment of the present application is shown in the figure.

[0049] Figure 3 The flowchart of pre-annealing the silicon carbide ingot of the embodiment of the present application is shown in the figure.

[0050] Figure 4 The flowchart of determining the optimal contact pressure of the embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0051] In order to make the purpose and advantages of the present application clearer and more apparent, the present application will be further described below in combination with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0052] The preferred embodiments of the present application will be described below with reference to the drawings. Those skilled in the art will appreciate that the embodiments are only used to explain the technical principles of the present application, and are not intended to limit the scope of protection of the present application.

[0053] It should be noted that, in the description of the present application, the terms of direction or position relationship such as "upper", "lower", "left", "right", "inner", "outer" and the like are based on the direction or position relationship shown in the drawings, which is only for the convenience of description, and does not indicate or imply that the device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0054] In addition, it should also be noted that, in the description of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. Those skilled in the art can understand the specific meaning of the above terms in the present application according to the specific circumstances.

[0055] Please refer to Figures 1-2 shown, Figure 1 is a flow chart of a preparation method of a semi-insulating silicon carbide substrate according to an embodiment of the present application, Figure 2 is a flow chart of determining the adjustment mode of the cutting parameters, and specifically, the present application provides a preparation method of a semi-insulating silicon carbide substrate, which comprises:

[0056] Step S1, mixing high-purity silicon powder and carbon powder according to a preset ratio to synthesize silicon carbide particles;

[0057] Step S2, loading the silicon carbide particles into a crucible and moving to a crystal growth device for crystal growth to obtain a silicon carbide ingot;

[0058] Step S3, cutting, grinding and polishing the silicon carbide ingot to obtain a silicon carbide single crystal substrate;

[0059] Step S4, high-temperature annealing and impurity removal treatment of the silicon carbide single crystal substrate to obtain a high-purity semi-insulating silicon carbide substrate;

[0060] During the cutting process, it comprises:

[0061] Step S31, pre-annealing treatment of the silicon carbide ingot, and cutting the silicon carbide ingot;

[0062] Step S32, collecting the contact pressure data between the cutting tool and the silicon carbide ingot, the temperature data of the cutting area, the cutting speed data, the cooling liquid flow and the integrity data of several wafers after cutting during the cutting process, the integrity data including the number of cracks and the kerf width;

[0063] Step S33, determining the optimal contact pressure according to the contact pressure data and the integrity data, and determining the optimal cutting temperature according to the temperature data and the integrity data;

[0064] Step S34, determining the adjustment mode of the cutting parameters according to the optimal contact pressure and the optimal cutting temperature;

[0065] Step S35, cutting the silicon carbide ingot according to the adjusted cutting parameters.

[0066] It can be understood that the silicon carbide substrate is prone to cracking during cutting, and the cutting time is long, so in order to reduce the risk of cracking and shorten the cutting time, the optimal contact pressure and the optimal cutting temperature between the cutting tool and the silicon carbide ingot are accurately determined, and then the adjustment mode of the cutting parameters is determined, so as to ensure the cutting quality.

[0067] In a specific embodiment, the process of preparing high-purity semi-insulating silicon carbide substrate is as follows: high-purity silicon powder and carbon powder are selected as raw materials, and the purity of the raw materials usually reaches more than 99.999%. The high-purity silicon powder and the carbon powder are uniformly mixed in a predetermined ratio of 1:1, and then synthesized under high temperature (such as more than 2000℃) and specific reaction conditions to generate silicon carbide particles. Then the synthesized silicon carbide particles are loaded into a crucible and then moved to a crystal growth device. In a closed growth chamber, the silicon carbide powder is sublimated by heating to produce reaction gas containing Si, SiC, C, and other different gas components. By controlling the temperature field and the transmission of the reaction gas, the sublimated components are recrystallized on the surface of the seed crystal, thereby growing a silicon carbide ingot. The silicon carbide ingot is then cut into thin slices of the required thickness, i.e. silicon carbide single crystal substrates, by using a diamond fine wire. Further grinding, polishing, high-temperature annealing and impurity removal are performed to improve the purity and quality of the silicon carbide single crystal substrate. 2 C, SiC 2

[0068] The present application can accurately determine the optimal cutting parameters (including contact pressure and cutting temperature) by pre-annealing the silicon carbide ingot and accurately collecting multiple key data during the cutting process, thereby optimizing the cutting process, improving the cutting quality and integrity of the silicon carbide single crystal substrate, reducing the problems of cracks and excessive kerf, and ensuring the preparation efficiency and quality of the final product.

[0069] Please refer to Figure 3 as shown, Figure 3 ​A flowchart of the pre-annealing process of the silicon carbide ingot according to the embodiments of the present application is shown in FIG. 1. Specifically, in step S31, the following steps are included:

[0070] In step S311, the annealing temperature and the annealing time are determined according to the residual stress in the silicon carbide ingot.

[0071] In step S312, the silicon carbide ingot is pre-annealed according to the annealing temperature and the annealing time.

[0072] It can be understood that the silicon carbide ingot will generate residual stress during the growth process, which may cause the wafer to break or crack during the cutting process. Through the pre-annealing process, the residual stress in the silicon carbide ingot can be released, thereby reducing the breakage rate during the cutting process.

[0073] Specifically, in step S311, the X-ray diffraction pattern of the silicon carbide ingot is collected, the diffraction data is determined according to the X-ray diffraction pattern, and the residual stress is determined according to the diffraction data. The diffraction data includes the diffraction peak position and the intensity change.

[0074] In one specific embodiment, XRD (X-ray diffraction) is used to detect the silicon carbide ingot, and the X-ray diffraction pattern is obtained to characterize the structure of the silicon carbide ingot and its change rule. After the X-ray diffraction pattern is smoothed and denoised, the lattice structure and stress state in the silicon carbide ingot can be preliminarily judged by observing the diffraction peak position and intensity change in the diffraction pattern. If the diffraction peak position shifts or the intensity changes, it indicates that there is residual stress in the silicon carbide ingot. The residual stress can be calculated by professional XRD software.

[0075] Specifically, the annealing time is determined according to the annealing temperature and the residual stress.

[0076] In one specific embodiment, the annealing temperature is determined according to the residual stress in the silicon carbide ingot. If the residual stress is greater than 20 MPa to 40 MPa, the annealing temperature is determined to be 1800℃ to 1850℃, and preferably the annealing temperature is 1810℃. The annealing time is 1h to 3h, and preferably the annealing time is 2h. The value range and preferred value of the annealing temperature and the annealing time can be determined according to the actual situation, which is not limited here and will not be described again.

[0077] The present application pre-anneals the silicon carbide ingot before cutting, determines the annealing time and the annealing temperature according to the residual stress in the silicon carbide ingot, thereby further releasing the residual stress in the silicon carbide ingot, reducing the breakage rate during the cutting process, improving the cutting quality and integrity of the silicon carbide single crystal substrate, reducing the problem of cracks and large cuts, and ensuring the preparation efficiency and quality of the final product.

[0078] Referring to Figure 4 shown, Figure 4 A flow chart for determining the optimal contact pressure for an embodiment of the present application. Specifically, in step S33, the optimal contact pressure is determined according to the contact pressure data and the completeness data, including:

[0079] Step S331, determining a pressure-crack function between the crack data and the contact pressure data according to the crack data and the contact pressure data;

[0080] Step S332, determining a pressure-slit function between the slit width and the contact pressure data according to the slit width and the contact pressure data;

[0081] Step S333, constructing a first comprehensive optimization objective function according to the first weight, the pressure-crack function, the second weight, and the pressure-slit function to determine the optimal contact pressure.

[0082] In one specific embodiment, the pressure-crack function and the pressure-slit function can be obtained by data fitting, while the minimum crack number and the minimum slit width are taken as the limiting conditions, and the optimal contact pressure is determined according to the limiting conditions and the pressure-crack function and the pressure-slit function. The first weight is the influence degree of the contact pressure on the wafer crack number, and the second weight is the influence degree of the contact pressure on the wafer slit width. The optimal contact pressure can be obtained by solving the minimum value of the first comprehensive optimization objective function according to the limiting conditions. Preferably, the first weight takes a value of 0.5, the second weight takes a value of 0.5, the minimum crack number takes a value in the range of 0-2, and preferably, the minimum crack number is 1. The minimum slit width takes a value in the range of 10 μm-30 μm, and preferably, the minimum slit width is 20 μm. In implementation, the value range and the preferred value of the first weight, the second weight, the minimum crack number, and the minimum slit width can be determined according to actual conditions, which will not be described herein.

[0083] Specifically, in step S33, the optimal cutting temperature is determined according to the temperature data and the completeness data, including:

[0084] Step S334, determining a temperature-crack function between the crack data and the temperature data according to the crack data and the temperature data;

[0085] Step S335, determining a temperature-slit function between the slit width and the temperature data according to the slit width and the temperature data;

[0086] Step S336, constructing a second comprehensive optimization objective function according to the third weight, the temperature-crack function, the fourth weight, and the temperature-notch function, to determine the optimal cutting temperature.

[0087] In one specific embodiment, the temperature-crack function and the temperature-notch function can be obtained by data fitting, and the minimum crack number and the minimum notch width are taken as the limiting conditions. The optimal cutting temperature is determined according to the limiting conditions, the temperature-crack function, and the temperature-notch function. The third weight is the influence degree of the temperature data on the wafer crack number, and the fourth weight is the influence degree of the temperature data on the wafer notch width. The optimal contact pressure can be obtained by solving the minimum value of the second comprehensive optimization objective function according to the limiting conditions. Preferably, the third weight is 0.5, the fourth weight is 0.5, the minimum crack number is in the range of 0-2, and preferably, the minimum crack number is 1. The minimum notch width is in the range of 10-30 μm, and preferably, the minimum notch width is 20 μm. In the implementation, the value range and the preferred value of the third weight, the fourth weight, the minimum crack number, and the minimum notch width can be determined according to the actual situation, which will not be described here.

[0088] The present application determines the optimal contact pressure according to the contact pressure data and the integrity data, and determines the optimal cutting temperature according to the temperature data and the integrity data, so as to further optimize the cutting parameters, improve the cutting quality and integrity of the silicon carbide single crystal substrate, reduce the problems of cracks and excessive notch, and ensure the preparation efficiency and quality of the final product.

[0089] Specifically, in step S4, the adjustment mode of the cutting parameters is determined, including:

[0090] If the pressure data is greater than or less than the optimal contact pressure, the cutting speed between the cutting tool and the silicon carbide crystal ingot is adjusted.

[0091] It can be understood that if the cutting speed changes, the contact pressure between the cutting tool and the silicon carbide crystal ingot will change, thereby affecting the cutting depth and the cutting effect. Therefore, according to the comparison result of the pressure data and the optimal contact pressure, the cutting speed between the cutting tool and the silicon carbide crystal ingot is adjusted.

[0092] Specifically, the adjustment amount of the cutting speed is determined, including:

[0093] A first correlation coefficient is determined according to the pressure data and the cutting speed data.

[0094] A pressure difference value is determined according to the pressure data and the optimal contact pressure.

[0095] determining an adjustment amount of the cutting speed according to the pressure difference value and the first correlation coefficient.

[0096] In one specific embodiment, the first correlation coefficient between the pressure data and the cutting speed data can be obtained by a Pearson correlation coefficient calculation formula, the pressure difference value is a difference between the pressure data and the optimal contact pressure, and the adjustment amount of the cutting speed is a product of the first correlation coefficient and the pressure difference value. In implementation, the adjustment amount of the cutting speed can be determined according to actual conditions, which is not specifically limited here and will not be described again.

[0097] According to the comparison result of the pressure data and the optimal contact pressure, the present application adjusts the cutting speed between the cutting tool and the silicon carbide crystal ingot, and then ensures the contact pressure between the cutting tool and the silicon carbide crystal ingot, so as to optimize the cutting process, improve the cutting quality and integrity of the silicon carbide single crystal substrate, reduce the problems of cracks and excessive incisions, and ensure the preparation efficiency and quality of the final product.

[0098] Specifically, in step S4, the adjustment manner of the cutting parameter is determined, including:

[0099] If the temperature data is greater than or less than the optimal cutting temperature, the flow of the cooling liquid in the cutting process is adjusted.

[0100] Specifically, the adjustment amount of the flow of the cooling liquid is determined, including:

[0101] A second correlation coefficient is determined according to the flow of the cooling liquid and the temperature data.

[0102] A temperature difference value is determined according to the temperature data and the optimal cutting temperature.

[0103] An adjustment amount of the flow of the cooling liquid is determined according to the temperature difference value and the second correlation coefficient.

[0104] It can be understood that the hardness of silicon carbide is large, and a large amount of heat will be generated during friction in the cutting process. Without the cooling liquid, the wafer will be overheated, which will affect the cutting quality and even damage the wafer. Therefore, the adjustment amount of the flow of the cooling liquid is determined according to the temperature data and the optimal cutting temperature data, which helps to reduce the temperature of the cutting area and prevent thermal deformation and thermal damage of the silicon carbide crystal ingot caused by excessively high temperature.

[0105] In one specific embodiment, the second correlation coefficient between the flow of the cooling liquid and the temperature data can be obtained by a Pearson correlation coefficient calculation formula, the temperature difference value is a difference between the temperature data and the optimal cutting temperature, and the adjustment amount of the flow of the cooling liquid is a product of the second correlation coefficient and the temperature difference value. In implementation, the adjustment amount of the flow of the cooling liquid can be determined according to actual conditions, which is not specifically limited here and will not be described again.

[0106] According to the comparison result of the temperature data and the optimal cutting temperature, the present application adjusts the coolant flow when the cutting tool cuts the silicon carbide ingot, and further prevents the thermal deformation and thermal damage of the silicon carbide ingot caused by the excessively high temperature, so as to optimize the cutting process, improve the cutting quality and integrity of the silicon carbide single crystal substrate, reduce the problems of cracks and excessively large incisions, and ensure the preparation efficiency and quality of the final product.

[0107] So far, the technical solutions of the present application have been described in combination with the preferred embodiments shown in the drawings, but those skilled in the art can easily understand that the protection scope of the present application is obviously not limited to these specific embodiments. Those skilled in the art can make equivalent changes or replacements to the related technical features without departing from the principles of the present application, and the technical solutions after the changes or replacements will all fall within the protection scope of the present application.

Claims

1. A method of producing a semi-insulating silicon carbide substrate, characterized by, The application relates to a method for preparing high-purity semi-insulating silicon carbide (SiC) substrates. The method comprises the following steps: S1. mixing high-purity silicon powder and carbon powder in a preset ratio to synthesize silicon carbide particles; S2. loading the silicon carbide particles into a crucible and moving to a crystal growth device for crystal growth to obtain a silicon carbide crystal ingot; S3. cutting, grinding and polishing the silicon carbide crystal ingot to obtain a silicon carbide single crystal substrate; S4. high-temperature annealing and impurity removal treatment of the silicon carbide single crystal substrate to obtain a high-purity semi-insulating silicon carbide substrate; In the cutting process, the method comprises the following steps: S31. pre-annealing treatment of the silicon carbide crystal ingot, and cutting of the silicon carbide crystal ingot; S32. collecting contact pressure data between a cutting tool and the silicon carbide crystal ingot, temperature data of a cutting area, cutting speed data, cooling liquid flow and completeness data of a plurality of wafers after cutting in the cutting process, wherein the completeness data comprises crack quantity and kerf width; S33. determining an optimal contact pressure according to the contact pressure data and the completeness data, comprising determining a pressure-crack function between crack quantity and contact pressure according to the crack quantity and the contact pressure data; determining a pressure-kerf function between kerf width and contact pressure according to the kerf width and the contact pressure data; constructing a first comprehensive optimization target function according to a first weight, the pressure-crack function, a second weight and the pressure-kerf function to determine the optimal contact pressure; determining an optimal cutting temperature according to the temperature data and the completeness data, comprising determining a temperature-crack function between crack quantity and temperature data according to the crack quantity and the temperature data; determining a temperature-kerf function between kerf width and temperature data according to the kerf width and the temperature data; constructing a second comprehensive optimization target function according to a third weight, the temperature-crack function, a fourth weight and the temperature-kerf function to determine the optimal cutting temperature; S34. determining an adjustment mode of cutting parameters according to the optimal contact pressure and the optimal cutting temperature, wherein if the pressure data is greater than or less than the optimal contact pressure, the cutting speed between the cutting tool and the silicon carbide crystal ingot is adjusted, and if the temperature data is greater than or less than the optimal cutting temperature, the cooling liquid flow in the cutting process is adjusted; 2. The method of producing a semi-insulating silicon carbide substrate according to claim 1, wherein S35. cutting of the silicon carbide crystal ingot according to the adjusted cutting parameters. In step S31, the method comprises the following steps: determining an annealing temperature and an annealing time according to residual stress in the silicon carbide crystal ingot; 3. The production method of a semi-insulating silicon carbide substrate according to claim 2, wherein pre-annealing treatment of the silicon carbide crystal ingot according to the annealing temperature and the annealing time. The method comprises the following steps:

4. The method of producing a semi-insulating silicon carbide substrate according to claim 3, wherein collecting X-ray diffraction patterns of the silicon carbide crystal ingot, determining diffraction data according to the X-ray diffraction patterns, and determining the residual stress according to the diffraction data, wherein the diffraction data comprises diffraction peak position and intensity change; 5. The method of producing a semi-insulating silicon carbide substrate according to claim 1, wherein determining the annealing time according to the annealing temperature and the residual stress. determining an adjustment amount of the cutting speed, comprising the following steps: determining a first correlation coefficient according to the pressure data and the cutting speed data; determining a pressure difference value according to the pressure data and the optimal contact pressure; determining the adjustment amount of the cutting speed according to the pressure difference value and the first correlation coefficient.

6. The method of producing a semi-insulating silicon carbide substrate according to claim 1, wherein Determining an adjustment amount of the coolant flow rate, comprising: Determining a second correlation coefficient according to the coolant flow rate and temperature data; Determining a temperature difference value according to the temperature data and the optimal cutting temperature; Determining the adjustment amount of the coolant flow rate according to the temperature difference value and the second correlation coefficient.

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