Inflation method for regulating and controlling growth rate of silicon carbide crystal and related device

Abstract

The invention discloses an inflation method for regulating and controlling the growth rate of silicon carbide crystals and a related device, and relates to the technical field of semiconductors, and the inflation method comprises the following steps: obtaining the mass loss rate of a silicon carbide crystal growth system based on a weighing sensor; the quality loss rate is compared with a theoretical loss rate, a deviation rate is obtained, and the theoretical loss rate is the quality loss rate meeting the production requirement under the current technology; acquiring a growth stage parameter, judging whether the growth stage parameter reaches a preset value or not, if the growth stage parameter reaches the preset value, adopting a first control strategy, and if the growth stage parameter does not reach the preset value, adopting a second control strategy, the growth stage parameters comprise the silicon carbide crystal thickness corresponding to the preset crystal growth time. According to the method, the uniformity of the resistivity of the silicon carbide crystal is improved by regulating and controlling the doping gas proportion in the growth process of the silicon carbide crystal.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to an inflation method and related device for regulating the growth rate of silicon carbide crystals. Background Art

[0002] Silicon carbide (SiC) single crystals, as a core substrate for third-generation semiconductor materials, hold broad application prospects in high-voltage power devices and high-frequency radio frequency devices. Currently, physical vapor transport (PVT) remains the mainstream method for growing large, high-quality SiC single crystals. However, most existing methods employ a constant dopant gas supply, making it difficult to achieve uniform and controllable resistivity. Therefore, regulating the dopant gas ratio during SiC crystal growth has become a pressing technical challenge in this field. Summary of the Invention

[0003] In view of the above problems, the present application provides a method and related device for regulating the growth rate of silicon carbide crystals to achieve the purpose of regulating the proportion of doping gas. The specific solution is as follows:

[0004] In a first aspect, the present application provides a gas filling method for regulating the growth rate of silicon carbide crystals, comprising:

[0005] Obtaining the mass loss rate of the silicon carbide crystal growth system based on a weighing sensor;

[0006] The deviation rate is obtained by comparing the mass loss rate with the theoretical loss rate. The theoretical loss rate is the mass loss rate that meets the production requirements under the current process.

[0007] Obtaining growth stage parameters and determining whether the growth stage parameters reach preset values, adopting a first control strategy if the growth stage parameters reach the preset values, and adopting a second control strategy if the growth stage parameters do not reach the preset values, wherein the growth stage parameters include a silicon carbide crystal thickness corresponding to a preset crystal growth time;

[0008] The first control strategy includes:

[0009] If the absolute value of the deviation rate is greater than the preset deviation rate, the doping gas flow rate is adjusted using a PI controller based on the first matching parameter; if the absolute value of the deviation rate does not exceed the preset deviation rate, the current doping gas flow rate is maintained;

[0010] The second control strategy includes:

[0011] If the absolute value of the deviation rate is greater than the preset deviation rate, the doping gas flow rate is adjusted using a PI controller based on the second matching parameter; if the absolute value of the deviation rate does not exceed the preset deviation rate, the current doping gas flow rate is maintained.

[0012] Optionally, the process of obtaining the theoretical loss rate includes: conducting n silicon carbide crystal growth experiments under the same process conditions to obtain a silicon carbide substrate, and based on the resistivity results of the silicon carbide substrate, reversely determining the mass loss rate that meets production requirements under the same process conditions and using it as the theoretical loss rate.

[0013] Optional, the process of obtaining the preset value includes:

[0014] Under the same process conditions, n silicon carbide crystal growth experiments are carried out, and the thickness of the silicon carbide crystal in the experiment is recorded at each time interval m to obtain a time-based silicon carbide crystal thickness growth table. Based on the resistivity results of the silicon carbide crystal, a preset value that meets production requirements is obtained.

[0015] Optionally, the silicon carbide crystal heating system includes: a silicon carbide crystal growth system, a bottom insulation layer, a top insulation layer and surrounding insulation layers; the weighing sensor includes: a first weighing sensor and a second weighing sensor, the first weighing sensor is integrated in the inner tray, and the second weighing sensor is integrated in the outer tray;

[0016] The bottom insulation layer, the top insulation layer and the surrounding insulation layers surround the silicon carbide crystal growth system;

[0017] The inner tray is arranged below the bottom insulation layer at the bottom of the silicon carbide crystal growth system and is used to weigh the mass of the silicon carbide crystal growth system and the bottom insulation layer;

[0018] The outer tray is arranged below the surrounding thermal insulation layer and is used to weigh the mass of the top thermal insulation layer and the surrounding thermal insulation layer.

[0019] Optionally, the mass loss rate of the silicon carbide crystal growth system is obtained based on a weighing sensor, including:

[0020] determining a first mass loss rate according to the masses of the inner tray obtained at different moments;

[0021] Determine the mass increase rate based on the mass of the outer tray at different times;

[0022] The mass increase rate is used to verify whether the first mass loss rate is distorted. If not, the first mass loss rate is used as the mass loss rate of the silicon carbide crystal growth system.

[0023] Optionally, the PI controller adjusts the doping gas flow rate, including: reducing the doping gas flow rate when the deviation rate is negative; and increasing the doping gas flow rate when the deviation rate is positive.

[0024] A second aspect of the present application provides an inflation device for regulating the growth rate of silicon carbide crystals, comprising:

[0025] A data acquisition module, which acquires the mass loss rate of the silicon carbide crystal growth system based on a weighing sensor;

[0026] A data comparison module is used to compare the mass loss rate with the theoretical loss rate to obtain a deviation rate. The theoretical loss rate is the mass loss rate that meets production requirements under the current process;

[0027] A control module is used to obtain growth stage parameters and determine whether the growth stage parameters reach preset values. If the growth stage parameters reach the preset values, a first control strategy is adopted; if the growth stage parameters do not reach the preset values, a second control strategy is adopted. The preset crystal growth time corresponds to the silicon carbide crystal thickness;

[0028] The first control strategy includes: if the absolute value of the deviation rate is greater than a preset deviation rate, adjusting the doping gas flow rate using a PI controller based on a first matching parameter; if the absolute value of the deviation rate does not exceed the preset deviation rate, maintaining the current doping gas flow rate;

[0029] Wherein, the second control strategy includes:

[0030] If the absolute value of the deviation rate is greater than the preset deviation rate, the doping gas flow is adjusted using a PI controller based on the second matching parameter; if the absolute value of the deviation rate does not exceed the preset deviation rate, the current doping gas flow is maintained.

[0031] A third aspect of the present application provides a computer program product comprising computer-readable instructions. When the computer-readable instructions are executed on an electronic device, the electronic device implements the inflation method for regulating the growth rate of silicon carbide crystals according to the first aspect or any implementation of the first aspect.

[0032] A fourth aspect of the present application provides an electronic device, comprising at least one processor and a memory connected to the processor, wherein:

[0033] Memory is used to store computer programs;

[0034] The processor is used to execute a computer program so that the electronic device can implement the inflation method for regulating the growth rate of silicon carbide crystals according to the first aspect or any implementation of the first aspect.

[0035] In a fifth aspect, the present application provides a computer storage medium carrying one or more computer programs. When the one or more computer programs are executed by an electronic device, the electronic device can implement the inflation method for controlling the growth rate of silicon carbide crystals according to the first aspect or any implementation of the first aspect.

[0036] By means of the above technical solution, the present application monitors the mass loss rate of the silicon carbide crystal growth system by installing a weighing sensor at the bottom of the growth furnace, and then compares it with the theoretical loss rate to obtain the deviation rate. On this basis, the growth stage parameters are used to judge the current growth process, and PI controllers with different matching parameters are used for segmented regulation, so that the doping gas flow rate can be automatically adapted and adjusted according to the growth stage. Compared with the shortcomings of the physical vapor transport method in the prior art, such as insufficient resistivity control accuracy and poor doping gas uniformity, the method proposed in this application realizes the regulation of the doping gas ratio during the growth process of silicon carbide crystals, thereby improving the resistivity uniformity of silicon carbide crystals. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The above and other features, advantages, and aspects of the various embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. Throughout the drawings, the same or similar reference numerals represent the same or similar elements. It should be understood that the drawings are schematic and that the originals and elements are not necessarily drawn to scale.

[0038] Figure 1 A schematic flow chart of a gasification method for regulating the growth rate of silicon carbide crystals provided in this application;

[0039] Figure 2 A schematic diagram of an algorithm flow of a gasification method for regulating the growth rate of silicon carbide crystals provided in this application;

[0040] Figure 3 A schematic diagram of a heating system structure provided for this application;

[0041] Figure 4 Schematic diagram of the average resistivity of Comparative Example 1 and Example 1 provided in this application;

[0042] Figure 5 Schematic diagram of the average resistivity of Comparative Example 2 and Example 2 provided in this application;

[0043] Figure 6 A schematic diagram of the structure of an inflation device for regulating the growth rate of silicon carbide crystals provided in this application;

[0044] Figure 7 This is a schematic block diagram of an electronic device provided in this application. DETAILED DESCRIPTION

[0045] The following describes the embodiments of the present application in conjunction with the accompanying drawings. The terms used in the implementation methods of the present application are only used to explain the specific embodiments of the present application and are not intended to limit the present application.

[0046] The embodiments of the present application are described below in conjunction with the accompanying drawings. Those skilled in the art will appreciate that, with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0047] The terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances, and this is merely a way of distinguishing the objects of the same attributes when describing them in the embodiments of the present application. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, so that the process, method, system, product or equipment comprising a series of units need not be limited to those units, but may include other units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0048] The present application provides a method for regulating the growth rate of silicon carbide crystals by gasification. Figure 1 , the method may include the following steps:

[0049] S101: Obtaining the mass loss rate of the silicon carbide crystal growth system based on a weighing sensor.

[0050] In this embodiment, a high-precision weighing sensor is installed at the bottom of the growth furnace. The sensor can adopt an electromagnetic force balance type or a piezoelectric structure. Its measurement accuracy can reach 0.01g and it can work stably for a long time in a high-temperature environment. Optionally, the weighing sensor is connected to the inner tray and the outer tray through a mechanical connector to collect the weight changes of the silicon carbide crystal growth system during the crystal growth process. During the high-temperature sublimation and deposition process of the silicon carbide raw material, the silicon carbide raw material is gradually consumed and deposited on the seed crystal, but a part of the silicon carbide vapor bypasses the seed crystal and crystallizes on the surface of the low-temperature insulation layer. Therefore, the total mass of the silicon carbide crystal growth system slowly decreases.

[0051] Specifically, a single tray with an integrated weighing sensor can be used to monitor the mass change of the silicon carbide crystal growth system, thereby obtaining the mass loss rate of the silicon carbide crystal growth system. It is also possible to use two inner and outer trays with integrated weight sensors to measure the heating system and the silicon carbide growth system respectively. There will be a cooling water flow outside the insulation layer of the heating system, so almost all the overflowed steam will crystallize on the insulation layer of the heating system, and the raw material vapor escaping to the outside of the heating system can be ignored, that is, the mass loss measured by the inner tray ≈ the raw material vapor in the silicon carbide crystal growth system + the mass increase measured by the outer tray. For example, the mass loss measured by the inner tray is 50 mg, and the mass increase measured by the outer tray is 15 mg. It can be seen that 15 mg of raw material vapor is crystallized on the insulation layer of the heating system, while 35 mg of raw material vapor is in the silicon carbide growth system. This application outputs mass data through the sampling frequency set by the weighing sensor, and distinguishes the inner and outer trays to accurately measure the mass loss of the inner tray, and can indirectly simulate whether the air pressure of the raw material vapor is suitable, and at the same time verify whether the data of the inner tray is distorted.

[0052] S102: Compare the mass loss rate with the theoretical loss rate to obtain a deviation rate. The theoretical loss rate is the mass loss rate that meets production requirements under the current process.

[0053] In this embodiment, the theoretical loss rate is obtained through experimental calibration. Specifically, under the same process conditions, such as the same temperature field distribution, atmosphere composition, pressure conditions and seed crystal orientation, multiple silicon carbide crystal growth experiments are carried out, and the resistivity of the resulting silicon carbide substrate can be measured by slicing and four-probe method. Combined with statistical analysis, the mass loss rate corresponding to the ideal resistivity requirement is determined, and this value is used as the theoretical loss rate. During the production process, the mass loss rate obtained in real time is compared with the theoretical loss rate to obtain the deviation rate. A positive deviation rate indicates that the actual consumption rate is higher than the target value, and gas phase supersaturation may occur, resulting in excessive growth of the silicon carbide crystal. When growing silicon carbide crystals of the same thickness, the doping gas will be reduced, resulting in a higher resistivity. A negative deviation rate indicates that the consumption rate is lower than the target value, indicating that the silicon carbide crystal is growing slowly. When the deviation rate is close to zero, it indicates that the silicon carbide crystal is at the optimal growth rate. By converting the relationship between the complex electrical properties of the silicon carbide crystal and the production parameters into a single indicator of deviation rate, the monitoring method of the silicon carbide crystal resistivity is simplified, and the control system can make quick decisions, thereby improving the stability of the process.

[0054] S103: Obtain growth stage parameters and determine whether the growth stage parameters reach preset values. If the growth stage parameters reach the preset values, a first control strategy is adopted; if the growth stage parameters do not reach the preset values, a second control strategy is adopted. The growth stage parameters include the silicon carbide crystal thickness corresponding to the preset crystal growth time.

[0055] In this embodiment, the growth stage parameters mainly include the silicon carbide crystal thickness corresponding to the preset crystal growth time. The silicon carbide crystal thickness corresponding to the preset crystal growth time is the thickness of the silicon carbide crystal when the crystal growth reaches the preset crystal growth time. The crystal thickness can be obtained in a variety of ways, such as calculation based on the crucible structure size and the initial thickness of the seed crystal, or non-contact measurement using an online optical interferometer. In the early growth stage, due to the presence of excessively high temperatures, the thermal field is more susceptible to the influence of the growth temperature. At this time, the system adopts a second control strategy to quickly correct the deviation in a relatively loose adjustment manner to ensure that the silicon carbide crystal enters the stable growth zone as soon as possible. When the cumulative growth time reaches the preset crystal growth time, for example, 20 hours, if the silicon carbide crystal thickness reaches the target value at this time, for example, 2mm, the system determines that the silicon carbide crystal has entered a stable period, and switches to the first control strategy at this time. The first control strategy focuses more on maintaining the stability of the silicon carbide crystal growth rate, maintaining the gas flow rate with a smaller adjustment range, so that the doping concentration is in the ideal range.

[0056] Specifically, if Figure 2 As shown, the control logic is as follows: First, the mass loss of the silicon carbide crystal growth system is obtained . Then calculate The rate of change relative to time t gives the mass loss rate , and the mass loss rate Compare this with the theoretical loss rate to get the deviation rate Then, determine the growth stage parameters Whether it reaches the preset value, if so, determine the deviation rate Whether it exceeds the preset deviation rate, if it exceeds, the doping gas flow rate is adjusted using a PI controller based on the first matching parameter, wherein the PI controller can be To adjust the doping gas flow rate, is the target value of the doping gas flow rate, is the current doping gas flow rate, is the first matching parameter. If the deviation rate is determined If the preset deviation rate is not exceeded, the current doping gas flow rate is maintained. If the preset value is not reached, the deviation rate is determined. Whether it exceeds the preset deviation rate, if it exceeds, the doping gas flow rate is adjusted using a PI controller based on the second matching parameter, wherein the PI controller can be To adjust the doping gas flow rate, is the second matching parameter. If the deviation rate is determined If the preset deviation rate is not exceeded, the current doping gas flow rate is maintained. By adopting differentiated control strategies at different growth stages of the silicon carbide crystal, the risk of growth rate fluctuation during the growth of the silicon carbide crystal is reduced.

[0057] In one embodiment, the process of obtaining the theoretical loss rate includes:

[0058] Under the same process conditions, n silicon carbide crystal growth experiments are carried out to obtain a silicon carbide substrate. Based on the resistivity results of the silicon carbide substrate, the mass loss rate that meets the production requirements under the same process conditions is reversely determined and used as the theoretical loss rate.

[0059] Specifically, first, n groups of silicon carbide crystal growth experiments are carried out under the same process conditions. The process conditions include the same crucible size, seed crystal orientation, temperature gradient, atmosphere pressure and doping gas flow rate. n can be 20, which ensures both the reliability of the experimental results and the efficiency of the experiment. After each experiment is completed, the obtained silicon carbide substrate is sliced ​​and its resistivity is measured by a four-probe method or a Hall effect test. Through statistical analysis of the resistivity data obtained from n experiments, combined with the production requirements of the target resistivity range, the most ideal mass loss rate that can meet the production needs under the process conditions is deduced. The most ideal mass loss rate is stored in the database as the theoretical loss rate. The subsequent actual growth process will compare the real-time measured mass loss rate with the theoretical loss rate to determine the deviation rate.

[0060] From the above, it can be concluded that the theoretical loss rate obtained through multiple experiments and resistivity back-calculation can truly reflect the most ideal mass loss rate that meets production requirements under specific process conditions, thereby providing a reliable benchmark basis for the subsequent dynamic regulation of the PI controller, improving the scientific nature of process control and the consistency of crystal products.

[0061] In one embodiment, the process of obtaining the preset value includes:

[0062] Under the same process conditions, n silicon carbide crystal growth experiments are carried out, and the thickness of the silicon carbide crystal in the experiment is recorded at each time interval m to obtain a time-based silicon carbide crystal thickness growth table. Based on the resistivity results of the silicon carbide crystal, a preset value that meets production requirements is obtained.

[0063] Specifically, the process conditions include the same crucible size, seed crystal orientation, temperature gradient, atmosphere pressure and doping gas flow rate, and n can be 20, which ensures both the reliability of the experimental results and the efficiency of the experiment. During each experiment, the system records the thickness of the silicon carbide crystal at a fixed time interval m (for example, every 10 minutes or every 30 minutes). Thickness measurement can be achieved in a variety of ways, such as non-contact measurement using an online laser interferometer, or detecting the relative position change of the seed crystal and the crucible structure through a built-in displacement sensor. By collecting and storing these data, a time-based silicon carbide crystal thickness growth table can be obtained, which clearly reflects the actual growth rate and thickness change trend of the crystal at different time points.

[0064] After the experiment, the resulting silicon carbide crystals were subjected to resistivity testing. The resistivity distribution at different locations was measured using either the four-probe method or the Hall effect method, and compared with the thickness growth curve for comparative analysis. Through comprehensive comparison of multiple experiments, the critical thickness and time points corresponding to meeting the target resistivity requirements (for example, a resistivity between 20–40 milliohm·cm and resistivity uniformity greater than 90%) were determined. This critical point parameter serves as a preset value to guide the judgment of the silicon carbide crystal growth stage during actual production.

[0065] From the above, we can conclude that by conducting multiple experiments under the same process conditions and combining them with resistivity analysis, it is possible to determine the critical point parameters at different growth stages, thereby obtaining scientifically reasonable preset values. This method not only ensures the accuracy of determining the growth stage of silicon carbide crystals, but also improves the timeliness and reliability of control strategy switching.

[0066] In one embodiment, the silicon carbide crystal heating system includes: a silicon carbide crystal growth system, a bottom insulation layer, a top insulation layer, and surrounding insulation layers; the weighing sensor includes: a first weighing sensor and a second weighing sensor, the first weighing sensor is integrated in the inner tray, and the second weighing sensor is integrated in the outer tray;

[0067] The bottom insulation layer, the top insulation layer and the surrounding insulation layers surround the silicon carbide crystal growth system;

[0068] The inner tray is arranged below the bottom insulation layer at the bottom of the silicon carbide crystal growth system and is used to weigh the mass of the silicon carbide crystal growth system and the bottom insulation layer;

[0069] The outer tray is arranged below the surrounding insulation layers and is used to weigh the masses of the surrounding insulation layers and the top insulation layer.

[0070] like Figure 3As shown, 1-4 are insulation layers, with 1 being the top insulation layer, 2 and 3 being the surrounding insulation layers (actually, four surrounding insulation layers are possible), and 4 being the bottom insulation layer. 5 is the SiC crystal growth system, 6 is the outer tray, and 7 is the inner tray. The SiC crystal growth system is the core reaction area and includes a graphite crucible, a graphite base, SiC raw materials, and seed crystals. Within this system, SiC crystals gradually grow via high-temperature sublimation-deposition. The bottom, top, and surrounding insulation layers form an insulated cavity surrounding the SiC crystal growth system, reducing heat loss and ensuring uniformity and stability of the temperature field within the furnace. To monitor material consumption and the actual growth status of the crystals in real time during the growth process, a dual-tray and dual-sensor design can be employed. For example, a first load cell integrated into the inner tray collects quality information about the SiC crystal growth system and its bottom insulation layer, while a second load cell integrated into the outer tray collects quality information about the top and surrounding insulation layers.

[0071] Specifically, the first weighing sensor and the second weighing sensor can adopt resistance strain gauge weighing sensors. Resistance strain sensors are based on the principle that resistance changes with strain, and have the characteristics of high sensitivity and fast response speed. Since the growth of silicon carbide crystals is a long and continuous process, the material consumption is manifested as a slow and steady reduction in mass, so the resistance strain gauge sensor can capture the mass changes of grams or even milligrams in real time. Secondly, the first weighing sensor can also adopt a capacitive sensor, and the second weighing sensor adopts an electromagnetic sensor. Capacitive sensors are insensitive to electromagnetic interference and can work stably in the environment of strong electromagnetic fields and high-temperature thermal radiation in the growth furnace. They are particularly suitable for placement in the inner tray position close to the crystal growth area, thereby ensuring the accuracy of local mass measurement. The second weighing sensor adopts an electromagnetic structure, which has small long-term drift and strong stability. It can maintain reliable measurement results during the crystal growth cycle of tens or even hundreds of hours.

[0072] From the above, it can be concluded that by weighing the inner and outer trays and performing calculations, the influence of the weight fluctuation of the insulation layer itself and the changes in the furnace environment can be effectively eliminated, thereby obtaining the true mass loss rate of the silicon carbide crystal growth system.

[0073] In one embodiment, obtaining a mass loss rate of a silicon carbide crystal growth system based on a load cell includes:

[0074] determining a first mass loss rate according to the masses of the inner tray obtained at different moments;

[0075] Determine the mass increase rate based on the mass of the outer tray at different times;

[0076] The mass increase rate is used to verify whether the first mass loss rate is distorted. If not, the first mass loss rate is used as the mass loss rate of the silicon carbide crystal growth system.

[0077] When obtaining the mass loss rate of the silicon carbide crystal growth system based on the weighing sensor, the system adopts a coordinated monitoring method of the inner tray and the outer tray. Specifically, based on the mass data collected by the inner tray at different times, a first mass loss rate is obtained. This rate directly reflects the mass loss rate of the silicon carbide crystal growth system caused by the silicon carbide vapor sublimated from the silicon carbide raw material overflowing from the silicon carbide crystal growth system during the growth process. At the same time, the outer tray is used to monitor the mass changes of the top insulation layer and the surrounding insulation layer. Since some silicon carbide vapor may condense on the surface of the top insulation layer and the surrounding insulation layer, the mass of the outer tray tends to increase over time. Therefore, the mass increase rate can be calculated based on the measurement values ​​of the outer tray at different times.

[0078] During the data verification process, the mass increase rate of the outer tray can be compared with the first mass loss rate of the inner tray in real time to determine the reliability of the first mass loss rate. If the comparison result shows that there is a significant deviation between the two, it indicates that the measurement result of the inner tray may be affected by factors such as thermal drift and vibration interference. The system will trigger the data correction process to eliminate abnormal data and ensure the accuracy of the final calculation result. Since the first mass loss rate represents the rate at which silicon carbide vapor overflows to the outside of the silicon carbide crystal growth system, and the mass increase rate represents the rate at which silicon carbide vapor condenses to the surface of the top insulation layer and the surrounding insulation layers, on the one hand, the mass increase rate must be a positive value, that is, it represents an increase in weight, and the first mass loss rate must represent a decrease in weight. On the other hand, the absolute value of the first mass loss rate cannot be continuously less than the absolute value of the mass increase rate over a long period of time. Based on these two aspects, the present application can use the mass increase rate to verify whether the first mass loss rate is distorted. When the requirements of any of the above two aspects are not met, it means that the first mass loss rate may be distorted.

[0079] From the above, we can see that by introducing the weighing of the outer tray, while ensuring the measurement sensitivity of the inner tray, real-time verification and adaptive correction functions of the measurement data are added, thereby effectively avoiding errors caused by drift or interference of a single sensor, improving the stability and reliability of mass loss rate monitoring during the growth of silicon carbide crystals, and providing more accurate data support for subsequent doping gas flow adjustment.

[0080] In one embodiment, the PI controller adjusts the doping gas flow rate, including: reducing the doping gas flow rate when the deviation rate is negative; and increasing the doping gas flow rate when the deviation rate is positive.

[0081] Among them, the PI controller is used to dynamically adjust the flow rate of the doping gas according to the positive or negative value of the deviation rate. When the mass loss rate obtained by real-time monitoring is compared with the theoretical loss rate, if the absolute value of the calculated deviation rate is greater than the preset deviation rate, the PI controller is used to adjust the doping gas flow rate. If the absolute value of the deviation rate does not exceed the preset deviation rate, the current doping gas flow rate is maintained. When the absolute value of the calculated deviation rate is greater than the preset deviation rate and the mass loss rate is less than the theoretical loss rate, it means that the actual material consumption rate is lower than the ideal level and the crystal growth rate is slow. At this time, the PI controller can be used to reduce the flow rate of the doping gas, so that the effective nitrogen raw material supply in the silicon carbide crystal growth environment is relatively reduced, thereby maintaining the resistivity of the silicon carbide crystal at a relatively uniform level. On the contrary, when the mass loss rate is greater than the theoretical loss rate, it means that the actual material consumption rate is higher than the ideal level and the crystal growth rate is fast. At this time, the PI controller automatically increases the flow rate of the doping gas, so that the effective nitrogen raw material supply in the silicon carbide crystal growth environment is relatively increased, thereby maintaining the resistivity of the silicon carbide crystal at a relatively uniform level.

[0082] Specifically, embodiment 1 uses a fixed parameter PI controller to control the flow rate of the doping gas, for example, real-time acquisition of the deviation rate , when the deviation rate is negative, press , reduce the flow rate of doping gas. When the deviation rate is positive, press To increase the flow rate of doping gas. Comparative Example 1 uses the traditional constant doping gas ratio. Figure 4 It can be seen that the resistivity average of Example 1 is more stable than that of Comparative Example 1.

[0083] Example 2 introduces the stage parameter L to dynamically adjust the parameters of the PI controller. For example, before the growth stage parameter L reaches the preset value, the second matching parameter To compensate the PI controller, , and when the deviation rate is negative, then press When the deviation rate is positive, the flow rate of the doping gas is reduced. To increase the flow rate of doping gas. After the growth phase parameter L reaches the preset value, the first matching parameter is used. To compensate the PI controller, , and when the deviation rate is negative, then press When the deviation rate is positive, the flow rate of the doping gas is reduced. To increase the flow rate of doping gas. Comparative Example 2 adopts the traditional constant doping gas ratio. Figure 5 It can be seen that the resistivity average value of Example 2 is more stable than that of Comparative Example 2.

[0084] From the above, it can be seen that the PI control strategy can achieve real-time and precise adjustment of the doping gas flow rate, thereby effectively keeping the silicon carbide crystal growth rate stable within the theoretical target range, ensuring the thickness uniformity of the silicon carbide crystal and improving the uniformity of resistivity control.

[0085] The above describes an inflation method for regulating the growth rate of silicon carbide crystals provided in an embodiment of the present application. The following describes an inflation device for performing the above-mentioned regulation of the growth rate of silicon carbide crystals.

[0086] See also Figure 6 , Figure 6 This is a schematic diagram of the structure of an inflation device for regulating the growth rate of silicon carbide crystals provided in an embodiment of the present application. Figure 6 As shown, the gas filling device for regulating the growth rate of silicon carbide crystals comprises:

[0087] A data acquisition module 301 is used to acquire the mass loss rate of the silicon carbide crystal growth system based on a weighing sensor;

[0088] A data comparison module 302 is used for comparing the mass loss rate with the theoretical loss rate to obtain a deviation rate, where the theoretical loss rate is the mass loss rate that meets the production requirements under the current process;

[0089] A control module 303 is configured to obtain growth stage parameters and determine whether the growth stage parameters have reached preset values. If the growth stage parameters have reached the preset values, a first control strategy is adopted; if the growth stage parameters have not reached the preset values, a second control strategy is adopted. The growth stage parameters include a silicon carbide crystal thickness corresponding to a preset crystal growth time.

[0090] The first control strategy includes: if the absolute value of the deviation rate is greater than a preset deviation rate, adjusting the doping gas flow rate using a PI controller based on a first matching parameter; if the absolute value of the deviation rate does not exceed the preset deviation rate, maintaining the current doping gas flow rate;

[0091] Wherein, the second control strategy includes:

[0092] If the absolute value of the deviation rate is greater than the preset deviation rate, the doping gas flow is adjusted using a PI controller based on the second matching parameter; if the absolute value of the deviation rate does not exceed the preset deviation rate, the current doping gas flow is maintained.

[0093] In one embodiment, the invention further comprises: a theoretical loss rate determination module, specifically configured to:

[0094] Under the same process conditions, n silicon carbide crystal growth experiments are carried out to obtain a silicon carbide substrate. Based on the resistivity results of the silicon carbide substrate, the mass loss rate that meets the production requirements under the same process conditions is reversely determined and used as the theoretical loss rate.

[0095] In one embodiment, the present invention further includes: a preset value determination module, specifically configured to:

[0096] Under the same process conditions, n silicon carbide crystal growth experiments are carried out, and the thickness of the silicon carbide crystal in the experiment is recorded at each time interval m to obtain a time-based silicon carbide crystal thickness growth table. Based on the resistivity results of the silicon carbide crystal, a preset value that meets production requirements is obtained.

[0097] In one embodiment, the bottom insulation layer, the top insulation layer and the surrounding insulation layers surround the silicon carbide crystal growth system;

[0098] The inner tray is arranged below the bottom insulation layer at the bottom of the silicon carbide crystal growth system and is used to weigh the mass of the silicon carbide crystal growth system and the bottom insulation layer;

[0099] The outer tray is arranged below the surrounding insulation layer and is used to weigh the mass of the top insulation layer and the surrounding insulation layer.

[0100] In one embodiment, the data acquisition module 301 is specifically configured to:

[0101] determining a first mass loss rate according to the masses of the inner tray obtained at different moments;

[0102] determining a mass increase rate according to the mass of the outer tray at different moments;

[0103] The mass increase rate is used to verify whether the first mass loss rate is distorted. If not, the first mass loss rate is used as the mass loss rate of the silicon carbide crystal growth system.

[0104] In one embodiment, the control module 303 controls the PI controller to adjust the doping gas flow rate specifically for:

[0105] When the deviation rate is negative, reduce the doping gas flow rate;

[0106] When the deviation rate is positive, the dopant gas flow rate is increased.

[0107] An electronic device is also provided in an embodiment of the present application. Figure 7, which shows a schematic diagram of the structure of an electronic device suitable for implementing the inflation method for regulating the growth rate of silicon carbide crystals in the embodiments of the present application. The electronic devices in the embodiments of the present application may include, but are not limited to, fixed terminals such as mobile phones, laptop computers, PDAs (personal digital assistants), PADs (tablet computers), desktop computers, and the like. Figure 7 The electronic device shown is merely an example and should not limit the functions and scope of use of the embodiments of the present application.

[0108] like Figure 7 As shown, the electronic device may include a processing device (e.g., a central processing unit, a graphics processing unit, etc.) 601, which can perform various appropriate actions and processes based on programs stored in a read-only memory (ROM) 602 or programs loaded from a storage device 608 into a random access memory (RAM) 603. When the electronic device is powered on, the RAM 603 also stores various programs and data required for the operation of the electronic device. The processing device 601, ROM 602, and RAM 603 are interconnected via a bus 604. An input / output (I / O) interface 605 is also connected to the bus 604.

[0109] Typically, the following devices may be connected to the I / O interface 605: an input device 606 including, for example, a touch screen, a touchpad, a keyboard, a mouse, a camera, a microphone, an accelerometer, a gyroscope, etc.; an output device 607 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; a storage device 608 including, for example, a memory card, a hard disk, etc.; and a communication device 609. The communication device 609 may allow the electronic device to communicate with other devices wirelessly or by wire to exchange data. Figure 7 The electronic device is shown with various devices, but it should be understood that it is not required to implement or possess all of the devices shown. More or fewer devices may be implemented or possessed instead.

[0110] An embodiment of the present application also provides a computer program product including computer-readable instructions. When the computer-readable instructions are executed on an electronic device, the electronic device implements any of the inflation methods for regulating the growth rate of silicon carbide crystals provided in the embodiments of the present application.

[0111] A computer-readable storage medium is also provided in an embodiment of the present application. The storage medium carries one or more computer programs. When the one or more computer programs are executed by an electronic device, the electronic device can implement any of the inflation methods for regulating the growth rate of silicon carbide crystals provided in the embodiment of the present application.

[0112] It should also be noted that the device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed across multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment. In addition, in the drawings of the device embodiments provided in this application, the connection relationship between the modules indicates that there is a communication connection between them, which can be specifically implemented as one or more communication buses or signal lines.

[0113] Through the description of the above embodiments, those skilled in the art can clearly understand that the present application can be implemented by means of software plus necessary general hardware, and of course can also be implemented by special hardware including application-specific integrated circuits, special CPUs, special memories, special components, etc. In general, all functions performed by computer programs can be easily implemented with corresponding hardware, and the specific hardware structures used to implement the same function can also be diverse, such as analog circuits, digital circuits or special circuits, etc. However, for the present application, software program implementation is a better implementation method in most cases. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a readable storage medium, such as a computer's floppy disk, USB flash drive, mobile hard disk, ROM, RAM, magnetic disk or optical disk, etc., and includes a number of instructions to enable a computer device (which can be a personal computer, training equipment, or network equipment, etc.) to execute the methods described in each embodiment of the present application.

[0114] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware, or any combination thereof. When implemented by software, all or part of the embodiments may be implemented in the form of a computer program product.

[0115] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website, a computer, a training device or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website, a computer, a training device or a data center. The computer-readable storage medium can be any available medium that a computer can store or a data storage device such as a training device, a data center, etc. that includes one or more available media integrations. The available medium can be a magnetic medium, (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)).

Claims

1. A method for regulating the growth rate of silicon carbide crystals by gasification, characterized in that: include: Obtaining the mass loss rate of the silicon carbide crystal growth system based on a weighing sensor; Comparing the mass loss rate with a theoretical loss rate to obtain a deviation rate, wherein the theoretical loss rate is the mass loss rate that meets production requirements under the current process; Obtaining growth stage parameters and determining whether the growth stage parameters reach preset values, adopting a first control strategy if the growth stage parameters reach the preset values, and adopting a second control strategy if the growth stage parameters do not reach the preset values, wherein the growth stage parameters include a silicon carbide crystal thickness corresponding to a preset crystal growth time; Wherein, the first control strategy includes: If the absolute value of the deviation rate is greater than the preset deviation rate, adjusting the doping gas flow rate using a PI controller based on the first matching parameter; if the absolute value of the deviation rate does not exceed the preset deviation rate, maintaining the current doping gas flow rate; Wherein, the second control strategy includes: If the absolute value of the deviation rate is greater than the preset deviation rate, the doping gas flow is adjusted using a PI controller based on the second matching parameter; if the absolute value of the deviation rate does not exceed the preset deviation rate, the current doping gas flow is maintained.

2. The method for controlling the growth rate of silicon carbide crystals according to claim 1, characterized in that: The process of obtaining the theoretical loss rate includes: Under the same process conditions, n silicon carbide crystal growth experiments are carried out to obtain a silicon carbide substrate. Based on the resistivity results of the silicon carbide substrate, the mass loss rate that meets the production requirements under the same process conditions is reversely determined and used as the theoretical loss rate.

3. The method for controlling the growth rate of silicon carbide crystals according to claim 1, wherein: The process of obtaining the preset value includes: Under the same process conditions, n experiments of silicon carbide crystal growth are carried out, and the thickness of the silicon carbide crystal in the experiment is recorded at each time interval m to obtain a growth table of the silicon carbide crystal thickness based on time, and the preset value that meets the production requirements is obtained based on the resistivity result of the silicon carbide crystal.

4. The method for controlling the growth rate of silicon carbide crystals according to claim 1, wherein: The silicon carbide crystal heating system includes: a silicon carbide crystal growth system, a bottom insulation layer, a top insulation layer and surrounding insulation layers; the weighing sensor includes: a first weighing sensor and a second weighing sensor, the first weighing sensor is integrated in the inner tray, and the second weighing sensor is integrated in the outer tray; The bottom insulation layer, the top insulation layer and the surrounding insulation layers surround the silicon carbide crystal growth system; The inner tray is arranged below the bottom insulation layer at the bottom of the silicon carbide crystal growth system and is used to weigh the mass of the silicon carbide crystal growth system and the bottom insulation layer; The outer tray is arranged below the surrounding thermal insulation layer and is used to weigh the mass of the top thermal insulation layer and the surrounding thermal insulation layer.

5. The method for controlling the growth rate of silicon carbide crystals according to claim 4, characterized in that: The mass loss rate of the silicon carbide crystal growth system is obtained based on a load cell, including: determining a first mass loss rate according to the masses of the inner tray obtained at different moments; determining a mass increase rate according to the mass of the outer tray at different moments; The mass increase rate is used to verify whether the first mass loss rate is distorted. If not, the first mass loss rate is used as the mass loss rate of the silicon carbide crystal growth system.

6. The method for controlling the growth rate of silicon carbide crystals according to claim 1, wherein: The PI controller adjusts the doping gas flow rate, including: When the deviation rate is negative, reducing the doping gas flow rate; When the deviation rate is positive, the doping gas flow rate is increased.

7. An inflation device for regulating the growth rate of silicon carbide crystals, characterized in that: include: A data acquisition module, used for acquiring the mass loss rate of the silicon carbide crystal growth system based on a weighing sensor; a data comparison module, configured to compare the mass loss rate with a theoretical loss rate to obtain a deviation rate, wherein the theoretical loss rate is the mass loss rate that meets production requirements under the current process; a control module, configured to obtain growth stage parameters and determine whether the growth stage parameters reach preset values, adopt a first control strategy if the growth stage parameters reach the preset values, and adopt a second control strategy if the growth stage parameters do not reach the preset values, wherein the growth stage parameters include a silicon carbide crystal thickness corresponding to a preset crystal growth time; The first control strategy includes: if the absolute value of the deviation rate is greater than a preset deviation rate, adjusting the doping gas flow rate using a PI controller based on a first matching parameter; if the absolute value of the deviation rate does not exceed the preset deviation rate, maintaining the current doping gas flow rate; Wherein, the second control strategy includes: If the absolute value of the deviation rate is greater than the preset deviation rate, the doping gas flow is adjusted using a PI controller based on the second matching parameter; if the absolute value of the deviation rate does not exceed the preset deviation rate, the current doping gas flow is maintained.

8. A computer program product, characterized in that The method comprises computer-readable instructions, which, when executed on an electronic device, enable the electronic device to implement the gas filling method for regulating the growth rate of silicon carbide crystals as claimed in any one of claims 1 to 6.

9. An electronic device, characterized in that: comprising at least one processor and a memory connected to the processor, wherein: The memory is used to store computer programs; The processor is configured to execute the computer program so that the electronic device can implement the gas filling method for regulating the growth rate of silicon carbide crystals as claimed in any one of claims 1 to 6.

10. A computer storage medium, characterized in that The storage medium carries one or more computer programs, which, when executed by an electronic device, enable the electronic device to implement the inflation method for regulating the growth rate of silicon carbide crystals as described in any one of claims 1 to 6.

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