Temperature measurement and mass production device and method for crystal growth furnace

Abstract

The invention discloses a crystal growth furnace temperature measurement mass production device which comprises a crystal growth furnace crucible, an induction heating coil, a crucible cavity upper cover, a thermocouple measurement module, an infrared temperature measurement window module and a hole filling heat preservation module, the induction heating coil is arranged on the periphery of the crystal growth furnace crucible, and the crucible cavity upper cover is arranged on the crystal growth furnace crucible. A plurality of holes are formed in the crucible cavity upper cover, and thermocouple measurement modules, infrared temperature measurement window modules and hole filling heat preservation modules are arranged in the holes. According to the technical scheme, the cost-reducing and efficiency-increasing temperature-measuring and mass-producing device for the crystal growth furnace is manufactured, the temperature-measuring device for the crystal growth furnace is combined with three crucible internal temperature distribution modes, so that accurate temperature measurement is obtained, the crystal growth efficiency and yield are improved on the basis of a thermal field effect of a crystal growth mass-producing process under an accurate control temperature condition, and the production cost is reduced. And meanwhile, the energy consumption and the maintenance cost of the crystal growth furnace can be saved, and the cost of mass production of crystal growth is integrally reduced.

Description

Technical Field

[0001] The present invention relates to the field of compound semiconductor crystal growth furnaces, and in particular to a temperature measurement mass production device and method for crystal growth furnaces. Background Art

[0002] Third-generation compound semiconductor materials offer superior properties, such as stability, electrical conductivity, thermal conductivity, melting point, voltage resistance, and electron drift rate, compared to first-generation semiconductor silicon substrates and second-generation compound semiconductors. They excel in high-temperature, high-frequency, and high-power applications, enabling industries such as electronics, communications, radio frequency, and power to break through the limitations of traditional substrate materials. Among these third-generation compound semiconductor materials, silicon carbide and gallium nitride are currently the preferred materials for high-temperature, high-power, and wide-bandgap devices. Both industrial and consumer electronics are trending toward lighter, thinner, shorter, smaller, and more multifunctional designs. Consequently, silicon carbide and gallium nitride offer high physical strength and corrosion resistance, as well as excellent electronic properties such as radiation hardness, high breakdown electric field, wide bandgap, high saturated electron drift velocity, and high-temperature operation.

[0003] Currently, the most common processes for growing silicon carbide and gallium nitride crystals are physical vapor transport (PVT) and physical vapor deposition (PVD), which have become the mainstream of mass production. The physical vapor transport method mainly uses silicon carbide and gallium nitride material powders to sublime in the heating zone of a high-temperature crucible. The temperature gradient promotes the migration of the silicon carbide and gallium nitride vapor phase to the seed crystal for the crystal growth process until the crystal block is completed. However, since the quality of crystals grown using the physical vapor transport method is closely related to the temperature conditions during the growth process, the difficulties include: first, the large number of synthesis parameters and countless combinations, making it difficult to find the optimal growth conditions; second, it is difficult to directly observe or control the interior of the crystal growth furnace, because growing single crystals requires controlling the temperature and flow of hot liquid in a completely enclosed device, which is almost a "black box operation." Therefore, conventional technology proposes to improve the quality, thermal stress, and defect density of the crystal block by controlling the temperature conditions of the crystal growth furnace. Taking the silicon carbide single crystal growth furnace as an example, the equipment used for silicon carbide single crystal growth usually includes a crucible and a heater. When the heater is powered on, a temperature field will be formed on the outside of the crucible, and the temperature field will heat the crucible. With the mass production of silicon carbide substrates, higher requirements are placed on the stability and repeatability of the process; especially the control of defects. Slight drift, change, or adjustment of the thermal field in the furnace will lead to lower quality of the grown crystal or increase the defect rate. That is, during single crystal growth, changes in heating temperature have a great impact on crystal growth. The optimal seeding temperature, crystal growth temperature, and cooling curve control procedures will affect the quality of the grown crystal block. The growth rate of the crystal block will increase rapidly as the heating temperature decreases.

[0004] It is difficult to mass-produce compound semiconductor materials and maintain the quality of grown crystals. Therefore, how to improve the growth rate and crystal quality by controlling various process parameters such as temperature and pressure is the current main development direction of crystal growth mass production. In the conventional invention patent CN111962147A, the most mature preparation method for silicon carbide crystals is the physical vapor transport (PVT) method, that is, in a crucible protected by a vacuum or inert gas atmosphere, at a certain temperature and pressure, the solid raw material silicon carbide powder decomposes and sublimates, moves from the relatively high temperature growth raw material area to the relatively low temperature growth interface area, and deposits and crystallizes on the silicon carbide seed crystal. It is known that the best impurity removal temperature is between 1400 and 1600 degrees Celsius and the best crystal growth temperature is between 2000 and 2200 degrees Celsius. At the same time, the conventional PVT method for growing silicon carbide crystals requires the establishment of a suitable temperature field to ensure the formation of a stable gas-phase silicon carbide transport flow from high temperature to low temperature, and to ensure that the gas-phase silicon carbide can nucleate and grow on the seed crystal. However, without a reliable temperature measurement technology, controlling the internal temperature is crucial to the quality of the product produced. Without accurate control of the temperature rise and fall curves, crystal quality cannot be guaranteed. Therefore, measuring and monitoring the temperature of the crystal growth furnace is a crucial means of controlling product quality. A common method for measuring the temperature of a high-temperature vacuum furnace is to use an infrared thermometer to collect the temperature signal of the crystal growth furnace through a temperature measuring glass.

[0005] Numerous researchers, both domestically and internationally, have studied silicon carbide crystal growth using various simulation methods, including its production process, graphitization, and powder sublimation. Their findings indicate that the temperature distribution across the crystal is initially uneven. As the process progresses, the temperature distribution gradually reaches an average value, maintaining a consistent growth rate during the initial growth phase. However, the growth rate slows as time and the crystal temperature increase. High temperatures are primarily concentrated on the crucible walls, causing the powder near the wall to vaporize and decompose first. However, recrystallization has been observed in the upper portion of the powder, with thermal stress primarily concentrated in the neck. The thermal field improvements mentioned are derived from simulation software used to simulate the growth environment, resulting in discrepancies with actual conditions. Furthermore, the particle size distribution of many raw materials (such as silicon carbide) varies, resulting in variations in the thermal field between growth experiments. Therefore, thermal field simulation alone cannot accurately determine the true temperature distribution within the crucible (growth furnace). Therefore, the industry is currently in urgent need of a temperature measurement device and mass production method for measuring the thermal field distribution inside the crucible. This device can be used to measure the actual thermal field distribution inside the crucible, completely overcoming the problem of temperature interference with crystal growth. At the same time, this temperature measurement device can be used to adjust the optimal thermal field distribution inside the crucible, thereby preventing temperature interference with raw materials or equipment and adjusting the optimal thermal field distribution inside the crucible to achieve large-scale mass production and growth of high-quality crystal blocks. Due to the high temperature of the crystal growth furnace during the silicon carbide single crystal growth process, the traditional infrared temperature measuring glass attached to the crystal growth furnace is prone to condensation of metal volatiles on the lower temperature temperature measuring glass surface, affecting the infrared thermometer's measurement through the glass and causing infrared thermometer reading errors. To improve the accuracy of temperature measurement, a small amount of inert gas is usually used to purge the temperature measuring glass, and the temperature measuring glass is replaced every one to two growth cycles. Therefore, temperature measurement causes large errors in thermal field distribution; and inert gas circulates in the crucible of the crystal growth furnace, generating heat convection exchange of heat energy, which will cause heat loss. The crystal growth furnace heater needs to increase power, which increases energy consumption costs; and the temperature measuring glass also needs to be replaced regularly, resulting in manpower and material costs.

[0006] The program used to simulate the thermal field distribution has a large error in its effect, but it can be used to quickly simulate the thermal field distribution inside the crucible before crystal growth. This allows R&D to understand the phenomena of electromagnetic induction, heat conduction, thermal field distribution, airflow formation, crystal growth process, thermal stress, crystal powder source consumption and defect generation inside the furnace.

[0007] The above-mentioned drawbacks have increased the production cost of the crystal growth furnace to varying degrees. Therefore, how to reduce the production cost and maintenance difficulty of the high-temperature furnace while ensuring the accuracy of temperature measurement is a technical problem that technicians in this field currently need to solve. Summary of the Invention

[0008] In order to solve the above problems, the present invention provides a crystal growth furnace temperature measurement mass production device that reduces costs and increases efficiency.

[0009] A crystal growth furnace temperature measurement mass production device in the present invention includes a crystal growth furnace crucible, an induction heating coil, a crucible cavity cover, a thermocouple measurement module, an infrared temperature measurement window module and a hole filling and insulation module. The crystal growth furnace crucible is surrounded by an induction heating coil, the crystal growth furnace crucible is provided with a crucible cavity cover, the crucible cavity cover is provided with a plurality of holes, and the holes are provided with a thermocouple measurement module, an infrared temperature measurement window module and a hole filling and insulation module.

[0010] In the above scheme, the crucible of the crystal growth furnace includes a crucible cavity, a crucible cavity cover, a crucible insulation layer, a crucible insulation cover and a seed table. The crucible cavity is provided with a crucible cavity cover, the crucible cavity is provided with a crucible insulation layer, the crucible insulation layer is provided with a crucible insulation cover, the crystal growth furnace crucible surrounded by the crucible insulation layer is provided with crystal growth raw materials, above the crystal growth raw materials is a sublimation atmosphere cavity, and above the sublimation atmosphere cavity is a seed table.

[0011] In the above scheme, the thermocouple measurement module includes a thermocouple connecting flange, a thermocouple protection cover, a thermocouple cooling water joint, a thermocouple cooling water pipeline, a thermocouple measurement module flange group and a thermocouple protection sleeve. The thermocouple connecting flange is provided with a thermocouple protection cover, and the thermocouple connecting flange is provided with a thermocouple cooling water joint. The thermocouple cooling water joint is connected to the thermocouple cooling water pipeline inside the thermocouple connecting flange. The thermocouple connecting flange and the thermocouple protection cover are connected through the thermocouple measurement module flange group. The thermocouple measurement module flange group is provided with a thermocouple protection sleeve.

[0012] In the above solution, thermocouple protection cover screws and thermocouple leak-proof sealing O-rings are provided between the thermocouple connecting flange and the thermocouple protection cover, and thermocouple fixing screws are also provided on the thermocouple connecting flange.

[0013] In the above scheme, the infrared temperature measurement window module includes an infrared connecting flange, an infrared protective cover, an infrared cooling water joint, an infrared cooling water pipeline and tempered glass. The infrared connecting flange is provided with an infrared protective cover, the infrared connecting flange is provided with an infrared cooling water joint, the infrared cooling water joint is connected to the infrared cooling water pipeline inside the infrared connecting flange, tempered glass is provided on the upper part of the infrared connecting flange, the infrared connecting flange and the infrared protective cover are hollow, and an infrared temperature measurement window is formed in the center of the infrared connecting flange and the infrared protective cover by tempered glass, and an infrared thermometer is provided in the infrared temperature measurement window.

[0014] In the above solution, infrared protection cover screws and infrared leak-proof sealing O-rings are provided between the infrared connection flange and the infrared protection cover, and infrared fixing screws are also provided on the infrared connection flange.

[0015] In the above solution, the tempered glass is heat-resistant tempered glass.

[0016] In the above scheme, the hole filling insulation module includes a hole filling connecting flange, a hole filling protective cover, a hole filling cooling water joint, a hole filling cooling water pipeline, a hole filling insulation pipe assembly, a hole filling insulation material and a hole filling insulation sleeve. The hole filling connecting flange is provided with a hole filling protective cover, the hole filling connecting flange is provided with a hole filling cooling water joint, the hole filling cooling water joint is connected to the hole filling cooling water pipeline inside the hole filling connecting flange, a hole filling insulation pipe assembly is provided between the hole filling connecting flange and the hole filling protective cover, the hole filling insulation pipe assembly is provided with a hole filling insulation material, and the hole filling insulation pipe assembly is provided with a hole filling insulation sleeve outside.

[0017] In the above solution, hole filling protective cover screws and hole filling leak-proof sealing O-rings are provided between the hole filling connecting flange and the hole filling protective cover, and hole filling fixing screws are also provided on the hole filling connecting flange.

[0018] A crystal growth furnace temperature measurement mass production method according to the above device is characterized by comprising the following steps:

[0019] S1: Simulate the temperature distribution of the thermal field based on the geometric data D1~D3, H1~H4, G1~G2 of the crystal growth furnace and the boundary conditions;

[0020] S2: inserting a plurality of thermocouple measurement modules into the crucible cavity cover and the crucible insulation cover, heating and measuring the thermal field temperature;

[0021] S3: Adjust the position of the induction heating coil to optimize the temperature distribution of the heat field in the crucible;

[0022] S4: Replace the thermocouple measurement module with multiple infrared temperature measurement window modules and monitor the thermal field temperature with an infrared thermometer;

[0023] S5: Precisely control the temperature distribution, airflow, and pressure parameters inside the crucible of the crystal growth furnace to meet the optimal conditions for crystal growth. The cooling time curve inside the crucible of the crystal growth furnace is determined to meet the stress and defect density requirements.

[0024] S6: placing the seed crystal and powder crystal into the crucible of the crystal growth furnace;

[0025] S7: Carry out the crystal growth process according to the above-set process parameters to complete crystal growth mass production.

[0026] The advantages and beneficial effects of the present invention are: the present invention provides a crystal growth furnace temperature measurement mass production device that reduces costs and increases efficiency, and utilizes the crystal growth furnace temperature measurement device in combination with three crucible internal temperature distribution modes to obtain accurate temperature measurement. On the basis of precisely controlling the temperature conditions for the thermal field effect of the crystal growth mass production process, the crystal growth efficiency and yield are improved, the quality of the crystal block is ensured, the defect density is reduced, and at the same time, the energy consumption and maintenance costs of the crystal growth furnace can be saved, thereby reducing the overall cost of crystal growth mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 It is a structural schematic diagram of the present invention;

[0029] Figure 2 It is a structural schematic diagram of the crucible of the crystal growth furnace of the present invention;

[0030] Figure 3 It is the side view of the thermocouple measurement module;

[0031] Figure 4 It is a top view of the thermocouple measurement module;

[0032] Figure 5 This is a side view of the infrared temperature measurement window module;

[0033] Figure 6 This is a top view of the infrared temperature measurement window module;

[0034] Figure 7 A side view of the insulation module filling the hole;

[0035] Figure 8 A top view of the insulation module filling the hole;

[0036] Figure 9 is a flow chart of the present invention;

[0037] Figure 10 It is the geometric diagram of the crystal growth furnace structure;

[0038] Figure 11 A schematic diagram of the temperature distribution of the internal thermal field of the crucible according to a specific embodiment of the crystal growth furnace temperature measurement device and the crystal growth mass production method provided by the present invention;

[0039] Figure 12A comparison chart showing the effect of mass production cooling time on finished products of the crystal growth furnace temperature measuring device of the present invention;

[0040] Figure 13 This is a picture of the finished product of the mass production of the crystal growth furnace temperature measuring device shown in the present invention.

[0041] In the figure: 1, crystal growth furnace crucible 2, induction heating coil 3, thermocouple measurement module 4, infrared temperature measurement window module 5, hole filling insulation module 11, crucible cavity 12, crucible cavity cover 13, crucible insulation layer 14, crucible insulation cover 15, seed stage 16, crystal growth material 17, sublimation atmosphere cavity 31, thermocouple connection flange 32, thermocouple protection cover 33, thermocouple cooling water connector 34, thermocouple cooling water pipeline 36, thermocouple measurement module flange assembly 37, thermocouple protection sleeve 38, thermocouple protection cover screw 39, thermocouple leak-proof sealing O-ring 310, thermocouple fixing screw 41, Infrared connecting flange 42, infrared protective cover 43, infrared cooling water connector 44, infrared cooling water pipeline 45, tempered glass 46, infrared temperature measuring window 47, infrared protective cover screw 48, infrared leak-proof sealing O-ring 49, infrared fixing screw 51, hole-filling connecting flange 52, hole-filling protective cover 53, hole-filling cooling water connector 54, hole-filling cooling water pipeline 55, hole-filling insulation pipe assembly 56, hole-filling insulation material 57, hole-filling insulation sleeve 58, hole-filling protective cover screw 59, hole-filling leak-proof sealing O-ring 510, hole-filling fixing screw DETAILED DESCRIPTION

[0042] The following embodiments are further described in conjunction with the accompanying drawings and examples. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0043] like Figure 1 As shown, the present invention is a mass-production device for measuring temperature in a crystal growth furnace, comprising a crystal growth furnace crucible 1, an induction heating coil 2, a crucible cavity cover 12, a thermocouple measurement module 3, an infrared temperature measurement window module 4, and a hole-filling and insulation module 5. The induction heating coil 2 is positioned around the crystal growth furnace crucible 1, and the crucible cavity cover 12 is positioned above the crucible 1. The crucible cavity cover 12 is provided with a plurality of holes, each containing a thermocouple measurement module 3, an infrared temperature measurement window module 4, and a hole-filling and insulation module 5. The adjustable induction heating coil 2 is used to heat the crystal growth furnace crucible 1. The coil's position can be adjusted to regulate the temperature distribution within the crucible. An optimal displacement range for the induction heating coil 2 is between 0 and 250 mm.

[0044] like Figure 2As shown, the crystal growth furnace crucible 1 includes a crucible cavity 11, a crucible cavity cover 12, a crucible insulation layer 13, a crucible insulation cover 14 and a seed stage 15. The crucible cavity 11 is provided with a crucible cavity cover 12, the crucible cavity 11 is provided with a crucible insulation layer 13, the crucible insulation layer 13 is provided with a crucible insulation cover 14, the crystal growth furnace crucible surrounded by the crucible insulation layer 13 is provided with a crystal growth raw material 16, above the crystal growth raw material 16 is a sublimation atmosphere cavity 17, and above the sublimation atmosphere cavity 17 is a seed stage 15.

[0045] The process temperature of the crystal growth furnace crucible 1 is controlled to be set between room temperature and 2300°C, wherein the impurity removal temperature is greater than 1000°C, and in this example, the impurity removal temperature is optimally between 1400°C and 1580°C; wherein the crystal growth temperature is set to be greater than 2000°C, and in this example, the crystal growth temperature is optimally between 2100°C and 2200°C;

[0046] like Figure 3 、 Figure 4 As shown, the thermocouple measurement module 3 has the following working characteristics: the temperature is raised from room temperature to the impurity removal temperature between 1400°C and 1580°C, which is the best; the temperature is then raised to the sublimation temperature of the crystal growth powder, wherein the crystal growth temperature is between 2100°C and 2200°C, which is the best; then after the crystal growth is completed, the temperature is slowly cooled from the high temperature corresponding to the time axis to room temperature; the temperature measuring thermocouple is a B-type thermocouple, and its temperature measuring range is between +600°C and +1700°C, which is the best; another set of K-type thermocouples, whose temperature measuring range is between 0°C and +1300°C, is the best.

[0047] The thermocouple measurement module 3 includes a thermocouple connection flange 31, a thermocouple protection cover 32, a thermocouple cooling water connector 33, a thermocouple cooling water pipeline 34, a thermocouple measurement module flange assembly 36, and a thermocouple protection sleeve 37. The thermocouple connection flange 31 is provided with a thermocouple protection cover 32, and the thermocouple connection flange 31 is provided with a thermocouple cooling water connector 33. The thermocouple cooling water connector 33 is connected to the thermocouple cooling water pipeline 34 inside the thermocouple connection flange 31. The thermocouple connection flange 31 and the thermocouple protection cover 32 are connected through the thermocouple measurement module flange assembly 36. A thermocouple protection sleeve 37 is provided outside the thermocouple measurement module flange assembly 36.

[0048] Thermocouple cover screws 38 and a thermocouple leak-proof O-ring 39 are installed between the thermocouple flange 31 and the thermocouple cover 32. Thermocouple fixing screws 310 are also installed on the thermocouple flange 31. The thermocouple is a type B thermocouple, with a positive electrode composed of a platinum-rhodium alloy containing 30% rhodium and a negative electrode composed of a platinum-rhodium alloy containing 6% rhodium. Its temperature measurement range is between +600°C and +1700°C.

[0049] like Figure 5 、 Figure 6As shown, the infrared temperature measurement window module 4 includes an infrared connection flange 41, an infrared protective cover 42, an infrared cooling water connector 43, an infrared cooling water pipeline 44, and tempered glass 45. The infrared connection flange 41 is provided with the infrared protective cover 42, and the infrared cooling water connector 43 is also provided on the infrared connection flange 41. The infrared cooling water connector 43 is connected to the infrared cooling water pipeline 44 inside the infrared connection flange 41. The infrared connection flange 41 is provided with tempered glass 45 on the top. The infrared connection flange 41 and the infrared protective cover 42 are hollow. The infrared connection flange 41 and the infrared protective cover 42 form an infrared temperature measurement window 46 in the center through the tempered glass 45. The infrared temperature measurement window 46 houses an infrared thermometer. The tempered glass 45 is heat-resistant tempered glass.

[0050] Infrared protective cover screws 47 and an infrared leak-proof sealing O-ring 48 are provided between the infrared connection flange 41 and the infrared protective cover 42. Infrared fixing screws 49 are also provided on the infrared connection flange 41. The infrared thermometer is a high-temperature infrared thermometer or a short-wave infrared thermometer; its measurement range is between -50°C and +2500°C. In this embodiment, a high-temperature infrared thermometer or a short-wave infrared thermometer is preferred.

[0051] An infrared light-transmitting window is positioned between the crucible cavity and the infrared temperature measurement window module, providing both thermal insulation and light transmission. A ring-shaped gasket, a fixing kit, and screws are employed to achieve a good seal. Industrial glass is a commonly used light-transmitting component and is readily available. Alternatively, other components that are light-transmitting, effectively sealable, and capable of withstanding moderate pressure, such as heat-resistant tempered glass, are optimal and would further achieve the objectives of the present invention and fall within the scope of protection of the present invention.

[0052] The working characteristics of infrared temperature measurement are as follows: the temperature is raised from room temperature to the optimal impurity removal temperature between 1400℃ and 1580℃; then the temperature is raised to the sublimation temperature of crystal growth powder, among which the optimal crystal growth temperature is between 2100℃ and 2200℃; then after the crystal growth is completed, the temperature is slowly lowered from the high temperature to room temperature according to the time axis.

[0053] like Figure 7 、 Figure 8As shown, the hole filling insulation module 5 includes a hole filling connecting flange 51, a hole filling protective cover 52, a hole filling cooling water joint 53, a hole filling cooling water pipeline 54, a hole filling insulation pipe assembly 55, a hole filling insulation material 56 and a hole filling insulation sleeve 57. The hole filling connecting flange 51 is provided with a hole filling protective cover 52, the hole filling connecting flange 51 is provided with a hole filling cooling water joint 53, the hole filling cooling water joint 53 is connected to the hole filling cooling water pipeline 54 inside the hole filling connecting flange 51, a hole filling insulation pipe assembly 55 is provided between the hole filling connecting flange 51 and the hole filling protective cover 52, a hole filling insulation material 56 is provided in the hole filling insulation pipe assembly 55, and a hole filling insulation sleeve 57 is provided outside the hole filling insulation pipe assembly 55.

[0054] A hole filling protective cover screw 58 and a hole filling leak-proof sealing O-ring 59 are provided between the hole filling connecting flange 51 and the hole filling protective cover 52 , and a hole filling fixing screw 510 is also provided on the hole filling connecting flange 51 .

[0055] The hole filling insulation material 56 is used alternately during the working period when the thermocouple measurement module and the infrared temperature measurement window module are withdrawn from the hole and do not need to perform temperature measurement, in order to increase the insulation effect and reduce energy consumption.

[0056] like Figure 9 As shown, a crystal growth furnace temperature measurement mass production method described in the above device includes the following steps:

[0057] S1: If Figure 10 As shown, the thermal field temperature distribution is simulated using the crystal growth furnace's geometric data D1~D3, H1~H4, G1~G2 and boundary conditions. The thermal field simulation mode is a calculation before crystal growth, which quickly simulates the thermal field distribution inside the crucible. This is used as a data simulation calculation for R&D to understand the electromagnetic induction, heat conduction, thermal field distribution, airflow formation, crystal growth process, thermal stress, crystal powder source consumption, and defect generation inside the furnace.

[0058] S2: inserting a plurality of thermocouple measurement modules into the crucible cavity cover and the crucible insulation cover, heating and measuring the thermal field temperature;

[0059] S3: Adjust the position of the induction heating coil to optimize the temperature distribution of the heat field in the crucible;

[0060] S4: Replace the thermocouple measurement module with multiple infrared temperature measurement window modules and monitor the thermal field temperature with an infrared thermometer;

[0061] S5: Precisely control the temperature distribution, airflow, and pressure parameters inside the crucible of the crystal growth furnace to meet the optimal conditions for crystal growth. The cooling time curve inside the crucible of the crystal growth furnace is determined to meet the stress and defect density requirements.

[0062] S6: placing the seed crystal and powder crystal into the crucible of the crystal growth furnace;

[0063] S7: Carry out the crystal growth process according to the above-set process parameters to complete crystal growth mass production.

[0064] like Figure 11 As shown, the thermal field simulation in S1 is a calculation before crystal growth, which quickly simulates the thermal field distribution inside the crucible. It is used as a data simulation calculation for the electromagnetic induction, heat conduction, thermal field distribution, airflow formation, crystal growth process, thermal stress, crystal powder source consumption and defect generation inside the furnace body to understand the situation. The simulation of the thermal field distribution program has a large error, but it can be used as a reference before crystal growth, and then monitored and assisted by thermocouples and infrared temperature measuring devices to achieve mass production. The finished product after mass production is shown in the figure below. Figure 12 shown.

[0065] The cooling water pipes mentioned in the above device are all general cooling water; general cooling water is tap water at room temperature and is a commonly used cooling medium. It is easy to obtain and can be used for heat exchange to remove heat energy near the measuring point, thereby reducing the temperature of the temperature measuring device. More preferably: the cooling water structure is process cooling water; the process cooling water temperature is lower than room temperature, and its heat exchange efficiency is high. The temperature difference is set to be above 10°C, and the temperature difference is between 10°C and 15°C. The water volume is between 50 liters and 80 liters per minute. Among them, it is best to use reverse osmosis water or pure water in the process cooling water, so that the pipes of the cooling water structure are not easily scaled and clogged. The effect of cooling is to reduce the temperature of the outer part of the crucible. The cooling effect can provide safety for the temperature measuring end, reduce crucible temperature leakage, and take into account both temperature stability and energy cost savings.

[0066] In a specific implementation example, the cooling time after the crystal growth process is completed is 3, 6, 9, 12, 15, 18, and 21 hours, respectively, from high temperature to room temperature, and the effects of different cooling times on the stress and defect density in the crystal are compared. The residual stress and defect density measurement results of the crystal block after cooling from high temperature to room temperature for different cooling times are as follows: Figure 13As shown, as the cooling time increases, the defect density within the ingot decreases and the residual stress value also decreases. However, as the cooling time increases to more than 12 hours, the rate of decrease slows, indicating that continuously extending the cooling time has little effect on reducing residual stress or defect density. According to the implementation case, when the ingot cools, the newly generated defects due to cooling cannot release thermal stress. Even if the defect density is low, it may cause the residual stress value to increase. Optimally, the specific implementation method sets a cooling time of less than 12 hours, and the residual stress and defect density are both positively correlated, which is a solution that balances quality and production capacity in mass production.

[0067] In a specific implementation example, thermal field simulation results revealed that the primary heating area is concentrated near the crucible wall. Numerical simulation methods were used to understand the distribution of the temperature and flow fields during the silicon carbide growth process. The physical behavior changes within the graphite crucible were analyzed, including heat flow, mass transfer, powder graphitization, crystal growth rate, and crystal morphology prediction. The reaction atmosphere flows upward from the outside toward the seed crystal surface. In this implementation example, after the crystal cools to room temperature, compressive stress is generated on the outside of the crystal and near the seed crystal, while tensile stress is generated at the growth front, resulting in a higher defect density in the center of the crystal.

[0068] In the specific implementation examples, the materials of the crucible in the hot field, graphite, porous graphite, tantalum carbide powder, etc. are all preferred universal materials. If used improperly, they may cause the defect of increased carbon inclusions; increasing the permeability of graphite, such as the use of porous graphite, is also a preferred solution; furthermore, if the permeability of porous graphite is still insufficient, additional holes can be opened to increase the permeability or tantalum carbide can be used, which has good hardness and rigidity, so porous tantalum carbide is the best.

[0069] In all the above specific implementation examples, the mass production method of the crystal growth furnace includes but is not limited to the above temperature measurement method and process method, which are not listed one by one here. Similar implementation examples can also achieve the purpose of the present invention.

[0070] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A crystal growth furnace temperature measurement mass production device, characterized in that: The invention comprises a crystal growth furnace crucible, an induction heating coil, a crucible cavity cover, a thermocouple measurement module, an infrared temperature measurement window module and a hole filling and insulation module. The crystal growth furnace crucible is surrounded by an induction heating coil, the crystal growth furnace crucible is provided with a crucible cavity cover, the crucible cavity cover is provided with a plurality of holes, and the holes are provided with a thermocouple measurement module, an infrared temperature measurement window module and a hole filling and insulation module.

2. A crystal growth furnace temperature measurement mass production device according to claim 1, characterized in that: The crystal growth furnace crucible includes a crucible cavity, a crucible cavity cover, a crucible insulation layer, a crucible insulation cover and a seed stage. The crucible cavity is provided with a crucible cavity cover, the crucible cavity is provided with a crucible insulation layer, the crucible insulation layer is provided with a crucible insulation cover, the crystal growth furnace crucible surrounded by the crucible insulation layer is provided with crystal growth raw materials, above the crystal growth raw materials is a sublimation atmosphere cavity, and above the sublimation atmosphere cavity is a seed stage.

3. The crystal growth furnace temperature measurement mass production device according to claim 1, characterized in that: The thermocouple measurement module includes a thermocouple connecting flange, a thermocouple protection cover, a thermocouple cooling water joint, a thermocouple cooling water pipeline, a thermocouple measurement module flange group and a thermocouple protection sleeve. The thermocouple connecting flange is provided with a thermocouple protection cover, the thermocouple connecting flange is provided with a thermocouple cooling water joint, the thermocouple cooling water joint is connected to the thermocouple cooling water pipeline inside the thermocouple connecting flange, the thermocouple connecting flange and the thermocouple protection cover are connected through the thermocouple measurement module flange group, and a thermocouple protection sleeve is provided outside the thermocouple measurement module flange group.

4. A crystal growth furnace temperature measurement mass production device according to claim 3, characterized in that: A thermocouple protection cover screw and a thermocouple leak-proof sealing O-ring are provided between the thermocouple connecting flange and the thermocouple protection cover, and a thermocouple fixing screw is also provided on the thermocouple connecting flange.

5. The crystal growth furnace temperature measurement mass production device according to claim 1, characterized in that: The infrared temperature measurement window module includes an infrared connecting flange, an infrared protective cover, an infrared cooling water joint, an infrared cooling water pipeline and tempered glass. The infrared connecting flange is provided with an infrared protective cover, the infrared connecting flange is provided with an infrared cooling water joint, the infrared cooling water joint is connected to the infrared cooling water pipeline inside the infrared connecting flange, tempered glass is provided on the upper part of the infrared connecting flange, the infrared connecting flange and the infrared protective cover are hollow, and an infrared temperature measurement window is formed in the center of the infrared connecting flange and the infrared protective cover by tempered glass, and an infrared thermometer is provided in the infrared temperature measurement window.

6. The crystal growth furnace temperature measurement mass production device according to claim 5, characterized in that: An infrared protection cover screw and an infrared leak-proof sealing O-ring are provided between the infrared connection flange and the infrared protection cover, and an infrared fixing screw is also provided on the infrared connection flange.

7. The crystal growth furnace temperature measurement mass production device according to claim 5, characterized in that: The tempered glass is heat-resistant tempered glass.

8. The crystal growth furnace temperature measurement mass production device according to claim 1, characterized in that: The hole-filling insulation module includes a hole-filling connecting flange, a hole-filling protective cover, a hole-filling cooling water joint, a hole-filling cooling water pipeline, a hole-filling insulation pipe assembly, a hole-filling insulation material and a hole-filling insulation sleeve. The hole-filling connecting flange is provided with a hole-filling protective cover, the hole-filling connecting flange is provided with a hole-filling cooling water joint, the hole-filling cooling water joint is connected to the hole-filling cooling water pipeline inside the hole-filling connecting flange, a hole-filling insulation pipe assembly is provided between the hole-filling connecting flange and the hole-filling protective cover, the hole-filling insulation pipe assembly is provided with a hole-filling insulation material, and the hole-filling insulation pipe assembly is provided with a hole-filling insulation sleeve outside.

9. The crystal growth furnace temperature measurement mass production device according to claim 8, characterized in that: A hole filling protective cover screw and a hole filling leak-proof sealing O-ring are provided between the hole filling connecting flange and the hole filling protective cover, and a hole filling fixing screw is also provided on the hole filling connecting flange.

10. A method for mass production of crystal growth furnace temperature measurement using the device of claim 1, characterized in that: The following steps are involved: S1: Simulate the temperature distribution of the thermal field based on the geometric data D1~D3, H1~H4, G1~G2 of the crystal growth furnace and the boundary conditions; S2: inserting a plurality of thermocouple measurement modules into the crucible cavity cover and the crucible insulation cover, heating and measuring the thermal field temperature; S3: Adjust the position of the induction heating coil to optimize the temperature distribution of the heat field in the crucible; S4: Replace the thermocouple measurement module with multiple infrared temperature measurement window modules and monitor the thermal field temperature with an infrared thermometer; S5: Precisely control the temperature distribution, airflow, and pressure parameters inside the crucible of the crystal growth furnace to meet the optimal conditions for crystal growth. The cooling time curve inside the crucible of the crystal growth furnace is determined to meet the stress and defect density requirements. S6: placing the seed crystal and powder crystal into the crucible of the crystal growth furnace; S7: Carry out the crystal growth process according to the above-set process parameters to complete crystal growth mass production.

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