Gallium oxide crystal growth control method and growth device

Abstract

The invention provides a growth control method and a growth device of a gallium oxide crystal, and the growth control method comprises the following steps: respectively obtaining a seeding control parameter, a reducing control parameter, a shouldering control parameter and an equal-diameter control parameter, and controlling a gallium oxide raw material in a growth furnace to execute seeding operation based on the seeding control parameter to obtain a preliminarily grown gallium oxide crystal; carrying out diameter shrinkage operation on the gallium oxide crystal after the seeding operation on the basis of the diameter shrinkage control parameter to obtain a diameter-reduced gallium oxide crystal; controlling the diameter-reduced gallium oxide crystal to execute a shouldering operation based on the shouldering control parameter to obtain a diameter-enlarged gallium oxide crystal; and performing equal-diameter operation on the gallium oxide crystals with the amplified diameters based on the equal-diameter control parameters to obtain gallium oxide crystals with consistent diameters. According to the device and the method disclosed by the embodiment of the invention, automatic control on growth of the gallium oxide crystal can be realized, and the defects of poor stability and high growth cost during manual operation are overcome.

Description

Technical Field

[0001] The present invention relates to the technical field of crystal growth, and in particular to a growth control method and a growth device for a gallium oxide crystal. Background Art

[0002] Gallium oxide (Ga 2 O 3 ) is a transparent semiconductor oxide. Among its five isomers (α, β, ε, δ, γ), the β phase is the most stable configuration and can be converted from other metastable phases of gallium oxide by high temperature treatment in air for a long enough time. 2 O 3 The materials are widely used in technologies such as metal oxide semiconductor field effect transistors (MOSFET), Schottky barrier diodes (SBD) and photodetectors.

[0003] At present, the growth control method of gallium oxide crystals is usually achieved by the inverted mold method, but the inverted mold method has high requirements for operators, requiring extremely rich gallium oxide growth experience and high training costs. On the other hand, the inverted mold method also requires real-time control based on monitoring data during the growth process, the human operation response is poor, and the repeatability of the process cannot be guaranteed, which is not conducive to the stable growth of gallium oxide crystals.

[0004] Therefore, the prior art needs to be further improved. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides a growth control method and a growth device for gallium oxide crystals, aiming to overcome the defects of the prior art in which the growth of gallium oxide crystals is controlled by manual operation, which leads to the defects of poor growth stability and high growth cost of gallium oxide crystals.

[0006] The technical solution adopted by the present invention to solve the technical problem is as follows:

[0007] In a first aspect, this embodiment discloses a method for controlling the growth of gallium oxide crystals, which comprises:

[0008] Acquire growth control parameters; wherein the growth control parameters include: seeding control parameters, diameter reduction control parameters, shoulder release control parameters and equal diameter control parameters;

[0009] Based on the seeding control parameters, the gallium oxide raw material in the growth furnace is controlled to perform a seeding operation to obtain a preliminarily grown gallium oxide crystal;

[0010] Performing a diameter reduction operation on the gallium oxide crystal after the seeding operation is completed based on the diameter reduction control parameter to obtain a gallium oxide crystal with a reduced diameter;

[0011] Based on the shoulder release control parameter, the gallium oxide crystal with a reduced diameter is controlled to perform a shoulder release operation to obtain a gallium oxide crystal with an enlarged diameter;

[0012] Based on the equal diameter control parameters, the equal diameter operation is performed on the enlarged diameter gallium oxide crystal to obtain the gallium oxide crystal with the same diameter.

[0013] Optionally, the growth furnace is provided with a pulling shaft, a temperature measuring thermocouple, a temperature measuring infrared probe, a weight sensor, and a pressure sensor; the seeding control parameters include: a first pulling speed, a thermocouple test temperature, an infrared temperature, a weight parameter, and a pressure value in the furnace;

[0014] The step of controlling the gallium oxide raw material in the growth furnace to perform a seeding operation based on the seeding control parameter to obtain a preliminarily grown gallium oxide crystal comprises:

[0015] Controlling the pulling shaft in the growth furnace to descend according to the first pulling speed, and synchronously detecting whether the pulling shaft is in contact with the seed crystal;

[0016] When it is detected that the lifting shaft has descended to contact the seed crystal, the lifting rod is controlled to continue to descend a specified distance under the preset thermocouple test temperature, infrared temperature and furnace pressure value to complete the seeding operation.

[0017] Optionally, the diameter reduction control parameters include: a second pulling speed and an output power;

[0018] The step of performing a diameter reduction operation on the gallium oxide crystal after the seeding operation is completed based on the diameter reduction control parameter to obtain a gallium oxide crystal with a reduced diameter comprises:

[0019] The output power and the second pulling speed are controlled synchronously, and when the output power rises to a preset power value, a gallium oxide crystal with a reduced diameter is obtained.

[0020] Optionally, the shoulder release control parameters include: output power, thermocouple test temperature, infrared temperature and furnace pressure value;

[0021] The step of controlling the gallium oxide crystal with a reduced diameter to perform a shoulder release operation based on the shoulder release control parameter to obtain the gallium oxide crystal with an enlarged diameter comprises:

[0022] Monitor the infrared temperature and pressure value in the furnace in real time, adjust the output power to make the infrared temperature reach the target temperature value, and determine whether the weight change amplitude is in an increasing state;

[0023] If the weight change amplitude is in an increasing state and the weight rises to the target value, the thermocouple test temperature is adjusted within the preset range, and the pulling speed is adjusted in real time according to the current weight value. When the weight value of the gallium oxide crystal and the current distance are within the preset shoulder release value, the shoulder release operation is completed to obtain a gallium oxide crystal with an enlarged diameter.

[0024] Optionally, the step of performing an equal-diameter operation on the enlarged-diameter gallium oxide crystals based on the equal-diameter control parameters to obtain gallium oxide crystals with uniform diameters includes:

[0025] When the current pulling speed of the gallium oxide crystal is equal to the preset pulling speed, the current position of the pulling axis and the current weight value of the gallium oxide crystal are recorded;

[0026] Determining a standard weight change range and a current weight change range of the gallium oxide crystal according to a current position of the pulling axis and a current weight value of the gallium oxide crystal;

[0027] The output power of the growth furnace is controlled based on the standard weight change amplitude and current weight change amplitude of the gallium oxide crystal under the predetermined thermocouple test temperature and furnace pressure value, and the seed crystal is pulled upward under the output power to perform the equal diameter operation.

[0028] Optionally, the process of controlling the output power of the growth furnace based on the standard weight change amplitude and the current weight change amplitude of the gallium oxide crystal specifically includes:

[0029] Determining a theoretical pulling distance of the gallium oxide crystal based on the pulling speed of the gallium oxide crystal;

[0030] When the sum of the standard weight change range and the preset increase rate variable value is greater than or equal to the current weight change range, and the difference between the standard weight change range and the preset increase rate variable value is less than or equal to the current weight change range;

[0031] adjusting the output power of the growth furnace based on the theoretical pulling distance of the gallium oxide crystal;

[0032] When the difference between the standard weight change range and the preset increase rate variable value is greater than the current weight change range;

[0033] adjusting the output power of the growth furnace based on the initial position and theoretical pulling distance of the gallium oxide crystal;

[0034] When the sum of the preset increase rate variable values ​​of the standard weight change range is less than the current weight change range;

[0035] The output power of the growth furnace is adjusted based on the current position of the gallium oxide and the theoretical pulling distance.

[0036] Optionally, the process of adjusting the output power of the growth furnace based on the theoretical pulling distance of the gallium oxide crystal specifically includes:

[0037] When the theoretical pulling distance is greater than the current position of the gallium oxide crystal, adjusting the output power of the growth furnace to a value having the same temperature drop rate as the growth furnace;

[0038] When the theoretical pulling distance is less than or equal to the current position of the seed crystal, the magnitude relationship between the standard weight change range and the current weight change range is re-determined.

[0039] Optionally, the process of adjusting the output power of the growth furnace based on the initial position and theoretical pulling distance of the gallium oxide crystal specifically includes:

[0040] Determining whether the current equal diameter stage of the gallium oxide crystal is the first equal diameter stage;

[0041] If the current equal diameter stage is not the first equal diameter stage of the gallium oxide crystal, a pause operation is performed for a preset time, the current pulling speed is reduced to 0, and the output power of the growth furnace is adjusted to a preset power;

[0042] When the theoretical pulling distance of the gallium oxide crystal is greater than the current position of the gallium oxide crystal, adjusting the power of the growth furnace to a first preset power;

[0043] When the theoretical pulling distance of the gallium oxide crystal is less than or equal to the current position of the gallium oxide crystal, the power of the growth furnace is adjusted to a second preset power.

[0044] Optionally, the process of adjusting the output power of the growth furnace based on the initial position and theoretical pulling distance of the gallium oxide crystal specifically includes:

[0045] When the current position of the gallium oxide crystal is greater than the sum of the theoretical pull-off distance and the preset distance and the current weight change amplitude of the gallium oxide crystal is less than the preset pull-off rate, determining the pulling speed of the growth furnace, and setting the output power of the growth furnace based on the pulling speed;

[0046] When the current position of the gallium oxide crystal is less than or equal to the sum of the theoretical pull-off distance and the preset distance and the current weight change amplitude is greater than the theoretical increase rate, pausing the current equal diameter operation and setting the output power of the growth furnace to a third preset power;

[0047] When the current position of the gallium oxide crystal is less than or equal to the sum of the theoretical pull-off distance and the preset distance and the current weight change amplitude is less than the theoretical increase rate, the current pulling speed is set to the preset speed, and the output power of the growth furnace is determined based on the theoretical pulling distance of the gallium oxide crystal and the current position of the gallium oxide crystal.

[0048] In a second aspect, this embodiment further discloses a gallium oxide crystal growth device, which includes: a growth furnace for growing gallium oxide crystals, a human-machine HMI module and a PLC control module connected to the growth furnace;

[0049] The human-machine HMI module is used to obtain growth control parameters and transmit the growth control parameters to the PLC control module;

[0050] The PLC control module is used to output a growth control signal for the gallium oxide crystal in the growth furnace according to the received growth control parameters, and send the growth control signal to the growth furnace;

[0051] The growth furnace is used to receive the growth control signal and perform corresponding control operations on the growth process of the gallium oxide crystal;

[0052] The growth furnace comprises a hollow reaction chamber, a lifting shaft arranged in the reaction chamber, a temperature rise and fall controller and a weight sensor;

[0053] The pulling axis is used to control the growth rate of the gallium oxide crystal according to the received growth control parameters;

[0054] The temperature control controller is used to adjust the temperature in the reaction chamber according to the received temperature control instruction;

[0055] The weight sensor is used to collect weight data of the gallium oxide crystals in the reaction chamber and transmit the weight data to the PLC control module.

[0056] Beneficial effect: The present invention provides a growth control method and a growth device for gallium oxide crystals, respectively obtaining seeding control parameters, diameter reduction control parameters, shoulder release control parameters and equal diameter control parameters, controlling the gallium oxide raw material in the growth furnace to perform seeding operation based on the seeding control parameters to obtain initially grown gallium oxide crystals; performing diameter reduction operation on the gallium oxide crystals after the seeding operation based on the diameter reduction control parameters to obtain reduced diameter gallium oxide crystals; controlling the reduced diameter gallium oxide crystals to perform shoulder release operation based on the shoulder release control parameters to obtain enlarged diameter gallium oxide crystals; performing equal diameter operation on the enlarged diameter gallium oxide crystals based on the equal diameter control parameters to obtain gallium oxide crystals with uniform diameters. The device and method of this embodiment can realize automatic control of the growth of gallium oxide crystals, avoiding the defects of poor stability and high growth cost during manual operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 is a flow chart of the steps of a method for controlling the growth of gallium oxide crystals provided in an embodiment of the present invention;

[0058] Figure 2is a principle flow chart of the growth control method of gallium oxide crystals according to an embodiment of the present invention;

[0059] Figure 3 is a flow chart of the steps of seeding operation in the growth control method according to an embodiment of the present invention;

[0060] Figure 4 is a flow chart of the steps of the diameter reduction operation in the growth control method according to an embodiment of the present invention;

[0061] Figure 5 is a flowchart of the steps of shoulder release operation in the growth control method according to an embodiment of the present invention;

[0062] Figure 6 is a flow chart of the steps of the equal diameter operation in the growth control method according to an embodiment of the present invention;

[0063] Figure 7 is a schematic structural diagram of a gallium oxide crystal growth device provided in an embodiment of the present invention; DETAILED DESCRIPTION

[0064] In order to make the purpose, technical solution and advantages of the present invention clearer and more specific, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0065] It will be understood by those skilled in the art that, unless expressly stated, the singular forms "one", "said", and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intermediate elements. In addition, the "connection" or "coupling" used herein may include wireless connection or wireless coupling. The term "and / or" used herein includes all or any unit and all combinations of one or more associated listed items.

[0066] The guided mold method (Edge-limited film feeding and pulling growth technology, EFG) is a method for growing high-quality gallium oxide single crystals. The implementation steps include: first processing the raw materials, drying the gallium oxide powder and loading it into the growth furnace, and then heating the gallium oxide powder to completely melt it into a liquid state. An iridium mold is placed in the center of the growth furnace, and the molten gallium oxide liquid is allowed to rise to the top surface through the mold by capillary action to form a thin film. The seed crystal is slowly placed in the molten gallium oxide liquid so that it contacts the film on the mold. Ensure that the contact between the seed crystal and the mold is good to facilitate the crystallization process. Use a controller to control the rotary pulling assembly to drive the pulling shaft to rotate and rise, and at the same time control the rotary assembly to drive the growth furnace to rotate synchronously. This process helps to form a uniform crystal structure and reduce the generation of defects. During the rotary pulling process, the seed crystal gradually crystallizes from the film on the mold, and finally forms the desired crystal shape. The growth rate and quality of the gallium oxide crystal can be optimized by adjusting the rotation speed, temperature and other parameters. When the gallium oxide crystal grows to the desired length, the rotary pulling is stopped and the temperature is gradually reduced. Finally, the gallium oxide crystals are removed from the growth crucible and subjected to subsequent processing, such as cutting, grinding and polishing.

[0067] In the prior art, the control of gallium oxide crystal growth is performed by manually adjusting parameters, which requires operators to observe the growth situation for a long time and make timely adjustments to the power and pulling speed. However, operators are not sensitive to slight parameter changes, which can easily lead to poor timeliness of operation. At the same time, operators are subjective when adjusting parameters, and the crystal growth process will be affected by behavioral habits, making it difficult to ensure the uniformity of the growth process parameter adjustment plan, and the growth process is unstable.

[0068] In order to overcome the above problems, the present embodiment discloses a growth control method and a growth device for gallium oxide crystals, which gradually control the gallium oxide raw materials and crystals in the growth furnace according to preset growth control parameters, and obtain gallium oxide crystals with consistent diameters through seeding operation, diameter reduction operation, shoulder release operation and equal diameter operation. The growth control method and the growth device disclosed in the present embodiment realize automatic control of gallium oxide crystal growth based on a control program, avoid inconsistent parameter adjustment and unstable growth process caused by strong subjectivity during manual operation, and automatically realize the growth process of gallium oxide crystals, saving economic and labor costs.

[0069] The embodiments of the present invention are further described below in conjunction with the accompanying drawings.

[0070] like Figure 1 As shown, a method for controlling the growth of gallium oxide crystals provided by an embodiment of the present invention comprises:

[0071] Step S1, obtaining growth control parameters; wherein the growth control parameters include: seeding control parameters, diameter reduction control parameters, shoulder release control parameters and equal diameter control parameters.

[0072] The method provided in this embodiment is applied to a gallium oxide crystal growth device, which includes a growth furnace, a human-machine HMI module and a PLC control module connected to the growth furnace. The human-machine HMI module receives the growth control parameters sent by the operator, the PLC control module obtains the growth control parameters received by the human-machine HMI module, and generates control information for the growth furnace according to the growth control parameters, and the control information is transmitted to the growth furnace to control the growth of the gallium oxide crystal in the growth furnace.

[0073] In this embodiment, the growth of the gallium oxide crystal includes four main stages: a seeding stage, a diameter reduction stage, a shoulder release stage and a diameter equalization stage. That is, the growth process of the gallium oxide crystal generally includes: a seeding operation, a diameter reduction operation, a shoulder release operation and a diameter equalization operation.

[0074] The seeding operation is to control the speed of pulling and rotating the gallium oxide seed crystal so that the seed crystal grows to the target position.

[0075] During the diameter reduction operation, after the seeding operation is completed, the diameter of the seed crystal is reduced by controlling the temperature and the pulling speed of the pulling shaft to eliminate the original defects of the seed crystal or the defects introduced due to temperature changes.

[0076] The shoulder release operation refers to the process of controlling the gallium oxide crystal to gradually increase its diameter to the desired size after the diameter is reduced. During the shoulder release process, the temperature and the stretching and pulling speed are reduced.

[0077] The equal diameter operation refers to the process of maintaining the crystal's stable diameter growth by precisely controlling the pulling speed and the temperature in the growth furnace after the shoulder release operation is completed. In the equal diameter stage, the pulling speed and temperature are required to be as stable as possible to ensure uniform growth of the crystal.

[0078] Therefore, the growth control parameters received in this step respectively include: a seeding control parameter corresponding to the seeding stage, a diameter reduction control parameter corresponding to the diameter reduction stage, a shoulder release control parameter corresponding to the shoulder release stage, and an equal diameter control parameter corresponding to the equal diameter stage. The seeding control parameter, diameter reduction control parameter, shoulder release control parameter, and equal diameter control parameter are respectively used to control the growth of gallium oxide crystals in the above-mentioned stages.

[0079] Combination Figure 2As shown, in the growth control process of gallium oxide crystals, the gallium oxide raw material in a molten state is first controlled to be slowly heated up. When the temperature reaches the specified temperature, it enters the seeding stage (i.e., the YJ stage in the figure). After the seeding stage is completed, it enters the diameter reduction stage (SJ stage). In the diameter reduction stage, the corresponding control of the rising, falling and rotation speed of the pulling shaft, and the temperature are controlled. After the diameter reduction stage is completed, it enters the shoulder release stage. In the shoulder release stage, the corresponding control of the rising, falling and rotation speed of the pulling shaft, and the temperature are controlled. After the shoulder release stage is completed, it enters the equal diameter stage. In the equal diameter stage, the corresponding control of the rising, falling and rotation speed of the pulling shaft, and the temperature are controlled. After the equal diameter stage is completed, it is slowly cooled to the target temperature to obtain gallium oxide crystals with consistent diameters.

[0080] In addition, the method for the growth device to obtain the growth control parameters is not only to obtain them from the human-machine HMI module, but also to obtain them from other connected intelligent devices, or to obtain them forwarded by other intelligent devices.

[0081] Step S2: Based on the seeding control parameters, the gallium oxide raw material in the growth furnace is controlled to perform a seeding operation to obtain initially grown gallium oxide crystals.

[0082] Seeding refers to the process of inserting a seed crystal into the molten gallium oxide raw material and starting to pull it. In the growth of gallium oxide crystals, the key to seeding is to control the temperature and the contact between the seed crystal and the melt. When the temperature is stable, the seed crystal can be brought into contact with the melt of the gallium oxide raw material and slowly pulled so that the seed crystal gradually enters the melt and begins to grow.

[0083] Specifically, the growth furnace is provided with a pulling axis, an infrared temperature sensor, a Z-axis servo, and a weight sensor; the seeding control parameters include: a first pulling speed, a thermocouple test temperature, an infrared temperature, a weight parameter, and a pressure value in the furnace.

[0084] The step of controlling the gallium oxide raw material in the growth furnace to perform a seeding operation based on the seeding control parameter to obtain a preliminarily grown gallium oxide crystal comprises:

[0085] Controlling the pulling shaft in the growth furnace to descend according to the first pulling speed, and simultaneously detecting whether the pulling shaft is in contact with the seed crystal;

[0086] Under the preset thermocouple test temperature, infrared temperature and furnace pressure value, the lifting rod is controlled to continue to descend a specified distance to complete the seeding operation.

[0087] like Figure 3As shown, in the seeding stage, the pulling shaft is first controlled to slowly descend at a first pulling speed of a preset time per hour. In specific implementation, while controlling the pulling shaft to slowly descend at a speed of 50 to 150 mm per hour, it is judged whether the seed crystal is contacted. If it is detected that the seed crystal is contacted, the value of the gravity sensor is controlled to be 0. In the process of contact between the gallium oxide raw material and the seed crystal, the weight change of the gallium oxide raw material is detected. When the weight change value is detected to be the first weight change value, the seeding stage is completed. Specifically, the first weight change value can be 10 g / h.

[0088] Step S3, performing a diameter reduction operation on the gallium oxide crystal after the seeding operation is completed based on the diameter reduction control parameter to obtain a gallium oxide crystal with a reduced diameter.

[0089] Specifically, the diameter reduction control parameters include: a second pulling speed and an output power;

[0090] The step of performing a diameter reduction operation on the gallium oxide crystal after the seeding operation is completed based on the diameter reduction control parameter to obtain a gallium oxide crystal with a reduced diameter comprises:

[0091] The output power and the second pulling speed are controlled synchronously, and when the output power rises to a preset power value, a gallium oxide crystal with a reduced diameter is obtained. In the specific implementation, the pressure value in the furnace is also controlled, that is, the pressure in the furnace is controlled by controlling the pressure relief valve on the growth furnace, so that the pressure value in the furnace is kept stable while controlling the output power and the pulling speed.

[0092] Combination Figure 4 As shown, in the diameter reduction stage, the pulling shaft is first controlled to rise at a fixed second pulling speed. In specific implementation, the second pulling speed can be 40 mm / h, and the output power (i.e., intermediate frequency power) of the growth furnace is synchronously controlled to rise to a preset power value. In specific implementation, the power can be increased by 200 W every 2 minutes. When the output power rises to the target power value, the diameter reduction operation is completed, and the target power value can be 10000 W.

[0093] Step S4, controlling the gallium oxide crystal with a reduced diameter to perform a shoulder release operation based on the shoulder release control parameter to obtain a gallium oxide crystal with an enlarged diameter.

[0094] The shouldering operation in the crystal growth process is: when the diameter of the gallium oxide crystal grows close to the predetermined target, the pulling speed and rotation speed are gradually increased to make the gallium oxide crystal transition from the diameter enlargement stage to the equal diameter growth stage. The purpose of the shouldering operation is to form a smooth shoulder on the surface of the gallium oxide crystal, laying the foundation for the subsequent equal diameter growth.

[0095] Specifically, the shoulder release control parameters include: output power, thermocouple test temperature, infrared temperature and furnace pressure value.

[0096] In this step, the steps of implementing the shoulder release operation based on the shoulder release control parameters include:

[0097] Monitor the infrared temperature and pressure value in the furnace in real time, adjust the output power to make the infrared temperature reach the target temperature value, and determine whether the weight change amplitude is in an increasing state;

[0098] If the weight change amplitude is in an increasing state and the weight rises to the target value, the thermocouple test temperature is adjusted to control the heating power, and the pulling speed and weight change amplitude are adjusted in real time according to the current weight value. When the weight value of the gallium oxide crystal and the current distance are at the preset shoulder release value, the shoulder release operation is completed to obtain a gallium oxide crystal with an enlarged diameter.

[0099] Combination Figure 5 As shown, after entering the shoulder release stage, the infrared temperature and the pressure value in the furnace are monitored in real time, and the output power of the growth furnace is adjusted to decrease the first slow-down power after the first preset time, decrease the second slow-down power after the second preset time, and decrease the third slow-down power after the third preset time. Then, the fourth slow-down power is decreased every time value in the fourth preset time period, and the output power is adjusted so that the infrared temperature reaches the target temperature value, and then in the next time, it is judged whether the weight value increases. If the weight change amplitude rises to a specified value, it is judged whether the weight reaches the target weight value. If the weight change amplitude does not increase, the infrared temperature is monitored repeatedly, and the steps of controlling the output power to decrease are controlled. When the weight reaches the target weight value and the weight change amplitude reaches the target data value, the temperature rise and fall control is performed, and it is judged whether to increase or decrease the temperature according to the speed of the weight change amplitude increase or decrease. If the increase is too fast, the temperature is raised, and if the weight change amplitude decreases, the temperature is lowered. The rise and fall value amplitude is determined by the difference. When the weight value of the gallium oxide crystal and the current distance are at the preset shoulder release value, the shoulder release operation is completed to obtain a gallium oxide crystal with an enlarged diameter, wherein the preset shoulder release value includes the preset weight value and the target distance value.

[0100] In one embodiment, the first preset time is 5 minutes, the second preset time is 15 minutes, the third preset time is 30 minutes, the first slow-down power is 200W / h, the second slow-down power is 100W / h, and the third slow-down power is 80W / h. When the weight change per minute increases by 150%, the thermocouple test temperature reaches the preset value, the pressure value in the furnace is maintained within the preset linear range, and the weight reaches more than 130g, the shoulder release operation is completed.

[0101] Step S5: performing an equal diameter operation on the enlarged diameter gallium oxide crystals based on the equal diameter control parameters to obtain gallium oxide crystals with uniform diameters.

[0102] The process corresponding to this step is the equal diameter stage. The control process of the equal diameter stage is to keep the diameter of the gallium oxide crystal unchanged and continue the amorphous growth process. In the equal diameter stage, the pulling speed and rotation speed need to be precisely controlled to ensure the consistency of crystal quality and size.

[0103] Furthermore, this step mainly includes the following steps:

[0104] Step S51: When the current pulling speed of the gallium oxide crystal is equal to the preset pulling speed, the current position of the pulling axis and the current weight value of the gallium oxide crystal are recorded.

[0105] The pulling speed of the pulling shaft in the growth furnace is monitored in real time. When the pulling speed is equal to the preset pulling speed, the current position of the pulling shaft and the current weight value of the gallium oxide crystal are recorded, and the pulling speed of the pulling shaft is continuously monitored.

[0106] Step S52: determining the standard weight change range and the current weight change range of the gallium oxide crystal according to the current position of the pulling axis and the current weight value of the gallium oxide crystal.

[0107] The pulling speed is controlled to change to a specified pulling speed value within a preset speed change time, and after waiting for a fixed time, the standard weight change range and the current weight change range are determined according to the current position of the pulling axis and the weight value of the gallium oxide crystal.

[0108] Step S53: controlling the output power of the growth furnace based on the standard weight variation range and the current weight variation range of the gallium oxide crystal.

[0109] This step controls the output power of the growth furnace according to the calculated standard weight change range and the current weight change range. Since the standard weight change range and the current weight change range are in different situations, the steps for controlling the output power are different.

[0110] Combination Figure 6 As shown, the process of controlling the output power of the growth furnace based on the standard weight change amplitude and the current weight change amplitude of the gallium oxide crystal specifically includes:

[0111] Determining a theoretical pulling distance of the gallium oxide crystal based on the pulling speed of the gallium oxide crystal;

[0112] When the sum of the standard weight change range and the preset increase rate variable value is greater than or equal to the current weight change range, and the difference between the standard weight change range and the preset increase rate variable value is less than or equal to the current weight change range, the output power of the growth furnace is adjusted based on the theoretical pulling distance of the gallium oxide crystal.

[0113] When the difference between the standard weight change amplitude and the preset increase rate variable value is greater than the current weight change amplitude, the output power of the growth furnace is adjusted based on the initial position of the gallium oxide crystal and the theoretical pulling distance.

[0114] When the sum of the preset increase rate variable values ​​of the standard weight change amplitude is less than the current weight change amplitude, the output power of the growth furnace is adjusted based on the current position of the gallium oxide and the theoretical pulling distance.

[0115] Step S54, pulling the seed crystal upward at the output power to perform an equal diameter operation.

[0116] When the output power of the current growth furnace is calculated according to the above step S53, the seed crystal is controlled to be pulled upward under the calculated output power to perform an equal diameter operation.

[0117] Specifically, the process of adjusting the output power of the growth furnace based on the theoretical pulling distance of the gallium oxide crystal specifically includes:

[0118] When the theoretical pulling distance is greater than the current position of the gallium oxide crystal, adjusting the output power of the growth furnace to a value having the same temperature drop rate as the growth furnace;

[0119] When the theoretical pulling distance is less than or equal to the current position of the seed crystal, the magnitude relationship between the standard weight change range and the current weight change range is re-determined.

[0120] Specifically, the process of adjusting the output power of the growth furnace based on the initial position and theoretical pulling distance of the gallium oxide crystal includes:

[0121] Determining whether the equal diameter stage of the gallium oxide crystal is the first equal diameter stage;

[0122] If the current equal diameter stage is not the first equal diameter stage of the gallium oxide crystal, a pause operation is performed for a preset time, the current pulling speed is reduced to 0, and the output power of the growth furnace is adjusted to a preset power;

[0123] When the theoretical pulling distance of the gallium oxide crystal is greater than the current position of the gallium oxide crystal, adjusting the power of the growth furnace to a first preset power;

[0124] When the theoretical pulling distance of the gallium oxide crystal is less than or equal to the current position of the gallium oxide crystal, the power of the growth furnace is adjusted to a second preset power.

[0125] Optionally, the process of adjusting the output power of the growth furnace based on the current position of the gallium oxide crystal and the theoretical pull-off distance specifically includes:

[0126] When the current position of the gallium oxide crystal is greater than the sum of the theoretical pull-off distance and the preset distance and the current weight change amplitude of the gallium oxide crystal is less than the preset pull-off rate, and the temperature value of the infrared sensor is used as a pre-judgment reference, the pulling speed of the growth furnace is determined, and the output power of the growth furnace is set based on the pulling speed so that the infrared temperature value matching the current furnace chamber reaches the preset temperature.

[0127] When the current position of the gallium oxide crystal is less than or equal to the sum of the theoretical pull-off distance and the preset distance and the current weight change amplitude is greater than the theoretical increase rate, pausing the current equal diameter operation and setting the output power of the growth furnace to a third preset power;

[0128] When the current position of the gallium oxide crystal is less than or equal to the sum of the theoretical pull-off distance and the preset distance and the current weight change amplitude is less than the theoretical increase rate, the current pulling speed is set to the preset speed, and the output power of the growth furnace is determined based on the theoretical pulling distance of the gallium oxide crystal and the current position of the gallium oxide crystal.

[0129] Combine the following Figure 6 The control steps of the equal diameter stage are further described in more detail. The control steps of the equal diameter stage include:

[0130] Step H1, driving the lifting shaft to perform lifting at an initial lifting speed.

[0131] Step H2, recording the current position of the pulling axis and the current weight of the gallium oxide crystal;

[0132] Step H3, the initial shoulder release speed value is transitioned to a preset speed for pulling.

[0133] Step H4, waiting for T2 minutes (eg 8 minutes), the purpose of the waiting time is to allow the temperature in the growth furnace to stabilize for a period of time.

[0134] Step H5, when Gtfdj (the standard weight change range after the real-time change distance is calculated by the parameters at the beginning of recording) + 10 is greater than or equal to Gtf (the current weight change range) and Gtf is greater than or equal to Gtfdj-10, execute step H5.1:

[0135] Step H5.1, if L5f (the theoretical distance calculated in 1 hour after the speed change) is greater than Ly (the current position), execute step H5.2. When L5f (the theoretical distance calculated in 1 hour after the speed change) is less than or equal to the current position, repeat step H5.

[0136] Step 5.2, controlling the output power to adjust the cooling rate in the growth furnace so that the current output power is equal to P5J I (constant radial cooling rate).

[0137] Step H6, when Gtf (current weight change) is less than Gtfdj-10%, execute step H6.1.

[0138] Step H6.1, determine whether it is the first cycle, if it is the first cycle, then execute step 6.3. If it is not the first cycle, then execute step H6.2.

[0139] Step H6.2, set a preset delay time T0 (for example: 10 minutes) and wait for the delay. If the time is not up, the cycle will be terminated without cooling. After the delay time is over, execute step H6.3.

[0140] Step H6.3, make the current pulling speed 0 and the output power = current output power - 150, and execute step H6.4.

[0141] Step H6.4, RSET T0 (reset the time of T0).

[0142] Step H6.5: when L1 S1 (initial position for recording) + L5f (theoretical distance in 1 hour after speed change) is greater than the current position, execute step H6.6; otherwise, execute step H6.7.

[0143] Step H6.6, set the current power equal to P5J I-25.

[0144] Step H6.7, set the current power equal to P5J I+25.

[0145] Step H7, when Gtf (current weight change) is greater than Gtfdj+10%, execute step 7.1.

[0146] Step H7.1, if the current position is greater than Lit (the theoretical pull-off distance calculated by the parameters at the beginning of recording) + 50 mm, execute step H7.11, otherwise execute step H7.21.

[0147] Step H7.11, when Gtf is less than -C01 (when pulled off, the weight change will become very small, when <-C01, it means it has been pulled off), execute step H7.12, otherwise return to step H7;

[0148] Step H7.12, set the current pulling speed to 80, set the recorded weight G l s3 to the current weight Gy, set the current position ll s2 to the current position, and execute step H7.13;

[0149] Step H7.13, set the current position to be greater than the current position + 20 mm;

[0150] Step H7.14, set the current pulling speed to 0;

[0151] Step H7.15, set the output power py equal to P5J1 / h (P5J1 is reduced per hour, 1W is one unit);

[0152] Step H7.16, set the output power py equal to 1000 to complete the equal-diameter control operation.

[0153] Step H7.21, when Gtf is greater than Gtfdj+20%, execute step H7.22, otherwise execute step H7.24.

[0154] Step H7.22, control Py to pause, the current pulling speed is 0;

[0155] Step H7.23, control the current power = current power + p2 l, that is, increase the current power by 200W, and jump to step 7.24.

[0156] Step H7.24, wait for 20 minutes (delay to allow the furnace conditions to stabilize), and execute step H7.25.

[0157] Step H7.25, set the current pulling speed to Vr (set speed value), and melt down 5mm (when the weight change is too large, some material will be melted back).

[0158] Step H7.26, set the current pulling speed to 0;

[0159] Step H7.27, when L1 S1+L5f is greater than the current position, jump to step H7.28, otherwise, jump to step H7.29;

[0160] Step H7.28, control the current power to be equal to P5J1–35, and jump to step H5;

[0161] Step H7.29, control the current power equal to P5J1+35, jump to step H5.

[0162] The method disclosed in this embodiment realizes the growth control of gallium oxide crystals in the growth furnace through the above steps respectively. The control method provided by this embodiment can not only meet the temperature field environment for the growth of gallium oxide crystals, but also control the V90 servo drive motor to make high-precision position displacement through Ethernet PROFINET communication, and combine the precise adjustment of power to increase and decrease temperature to control the growth process, thereby solving the current difficulties in the accuracy and timeliness of manual control of temperature and position.

[0163] In a second aspect, this embodiment also provides a gallium oxide crystal growth device, such as Figure 7 , including: a growth furnace for growing gallium oxide crystals, a human-machine HMI module and a PLC control module connected to the growth furnace.

[0164] The human-machine HMI module is used to obtain growth control parameters and transmit the growth control parameters to the PLC control module. The human-machine HMI module is provided with an information input unit and / or an information receiving unit. The information input unit can receive the growth control parameters input by the operator. The growth control parameters can be temperature control parameters, input power control parameters or pulling control parameters, etc. The growth control parameters can be controlled by touch, or by a mouse, keyboard or key. The information receiving unit can establish a connection with other external devices, obtain files or information containing user-defined growth control parameters through the communication connection, and then parse the files or information to obtain the user-defined growth control parameters.

[0165] The PLC control module is used to output a growth control signal for the gallium oxide crystal in the growth furnace according to the received growth control parameters, and send the growth control signal to the growth furnace.

[0166] The PLC control module is a controller that stores programs. After the operator compiles the control program according to the growth control requirements of the gallium oxide crystal, the operator uses a programmer to input the program into the memory in the PLC control module for storage. The PLC control module can output control signals according to the control program stored in the memory to control the operation of the connected hardware. The connected hardware can be a servo motor that drives the lifting shaft to rotate and rise or fall, a medium-frequency power supply control board that controls the output power change, a solenoid valve or a water pump, etc. The sensor part can include a weight sensor and a temperature sensor. The PLC control module obtains weight data and temperature data, and drives the servo motor to move according to the calculated weight change amplitude and other data, and controls the temperature rise and fall process to achieve the smooth growth of gallium oxide crystals.

[0167] In one implementation, the weight sensor uses the HBM-Z6 imported high-precision sensor, which is combined with the AED9101D acquisition module and transmitted to the CPU via RS485 free port communication. After the original weight data is collected, a series of algorithms such as derivatives and average changes are used to calculate the weight ratio, weight change amplitude, adaptive filtering and other data, providing accurate collection basis for system process execution.

[0168] The medium frequency heating and cooling system for temperature control set in the PLC control module can also communicate with the CPU through RS485RTU mode, set the communication format such as baud rate 9.6kbps, parity check none, data bit 8-bit character, etc., combine PLC instructions to read and write communication data, and the system converts and processes the data. The slow control temperature mode adopts the program algorithm combined with the CPU timer function to calculate and accurately control the temperature power within the range of 1 watt, so that the coil temperature in the chamber of the growth furnace remains constant and controllable.

[0169] The specific execution of the automatic crystal growth step is carried out according to the program logic and internal calculations. When operating, you only need to enter the parameters of the corresponding process in the human-machine HMI interface. After switching to automatic mode, click the switch to automatic button to realize the process of unmanned crystal growth. When the human-machine HMI module receives the growth control parameters input by the operator, it generates a growth control signal according to the growth control program stored internally, and inputs the growth control signal to the growth furnace. The growth control signal is a signal for controlling the process of the growth raw material of the gallium oxide crystal in the growth furnace growing into gallium oxide crystals. The growth control signal includes: temperature control signal, input power control signal, pulling control signal or other signals for controlling crystal growth.

[0170] The growth furnace is used to receive the growth control signal and perform corresponding control operations on the growth process of the gallium oxide crystal.

[0171] When the growth furnace receives the growth control signal, it controls the gallium oxide crystal during its growth process according to the received growth control signal.

[0172] Specifically, the process of controlling the growth process of the gallium oxide crystal based on the growth control signal in the growth furnace includes: the growth furnace performs a seeding operation on the gallium oxide crystal, and after the seeding operation is completed, performs a diameter reduction operation on the gallium oxide crystal to obtain a gallium oxide crystal with a reduced diameter, and controls the growth furnace to perform a shoulder release operation on the gallium oxide crystal with a reduced diameter to obtain a gallium oxide crystal with an enlarged diameter, and performs a diameter equalization operation on the gallium oxide crystal with the enlarged diameter to obtain a gallium oxide crystal with a uniform diameter; and controls the growth furnace to perform a crystallization operation on the gallium oxide crystal with a uniform diameter to obtain a target gallium oxide crystal.

[0173] The lifting shaft communicates with the PLC control module via a switch, and the temperature rise and fall controller and the sensor communicate with the PLC control module via an RS485 free port.

[0174] The PLC control module provided in this embodiment can also design a system software with adaptive crystal growth through recipe and self-learning system functions. The software system can be applied to the growth of crystals with the same process, and can be used to grow crystals of different sizes through recipe and parameter adjustment.

[0175] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for controlling the growth of gallium oxide crystals, characterized in that: include: Acquire growth control parameters; wherein the growth control parameters include: seeding control parameters, diameter reduction control parameters, shoulder release control parameters and equal diameter control parameters; Based on the seeding control parameters, the gallium oxide raw material in the growth furnace is controlled to perform a seeding operation to obtain a preliminarily grown gallium oxide crystal; Performing a diameter reduction operation on the gallium oxide crystal after the seeding operation is completed based on the diameter reduction control parameter to obtain a gallium oxide crystal with a reduced diameter; Based on the shoulder release control parameter, the gallium oxide crystal with a reduced diameter is controlled to perform a shoulder release operation to obtain a gallium oxide crystal with an enlarged diameter; Based on the equal diameter control parameters, the equal diameter operation is performed on the enlarged diameter gallium oxide crystal to obtain the gallium oxide crystal with the same diameter.

2. The method for controlling the growth of gallium oxide crystals according to claim 1, characterized in that: The growth furnace is provided with a pulling shaft, a temperature measuring thermocouple, a temperature measuring infrared probe, a weight sensor, and a pressure sensor; the seeding control parameters include: a first pulling speed, a thermocouple test temperature, an infrared temperature, a weight parameter, and a pressure value in the furnace; The step of controlling the gallium oxide raw material in the growth furnace to perform a seeding operation based on the seeding control parameter to obtain a preliminarily grown gallium oxide crystal comprises: Controlling the pulling shaft in the growth furnace to descend according to the first pulling speed, and synchronously detecting whether the pulling shaft is in contact with the seed crystal; When it is detected that the lifting shaft has descended to contact the seed crystal, the lifting rod is controlled to continue to descend a specified distance under the preset thermocouple test temperature, infrared temperature and furnace pressure value to complete the seeding operation.

3. The method for controlling the growth of gallium oxide crystals according to claim 1, characterized in that: The diameter reduction control parameters include: a second pulling speed and output power; The step of performing a diameter reduction operation on the gallium oxide crystal after the seeding operation is completed based on the diameter reduction control parameter to obtain a gallium oxide crystal with a reduced diameter comprises: The output power and the second pulling speed are controlled synchronously, and when the output power rises to a preset power value, a gallium oxide crystal with a reduced diameter is obtained.

4. The method for controlling the growth of gallium oxide crystals according to claim 1, characterized in that: The shoulder release control parameters include: output power, thermocouple test temperature, infrared temperature and furnace pressure value; The step of controlling the gallium oxide crystal with a reduced diameter to perform a shoulder release operation based on the shoulder release control parameter to obtain the gallium oxide crystal with an enlarged diameter comprises: Monitor the infrared temperature and pressure value in the furnace in real time, adjust the output power to make the infrared temperature reach the target temperature value, and determine whether the weight change amplitude is in an increasing state; If the weight change amplitude is in an increasing state and the weight rises to the target value, the output power is adjusted to make the thermocouple test temperature within the preset range, and the pulling speed is adjusted in real time according to the current weight change amplitude. When the weight value of the gallium oxide crystal and the current distance are within the preset shoulder release value, the shoulder release operation is completed to obtain a gallium oxide crystal with an enlarged diameter.

5. The method for controlling the growth of gallium oxide crystals according to claim 1 or 4, characterized in that: The step of performing equal-diameter operation on the enlarged-diameter gallium oxide crystals based on the equal-diameter control parameters to obtain gallium oxide crystals with uniform diameters comprises: When the current pulling speed of the gallium oxide crystal is equal to the preset pulling speed, the current position of the pulling axis and the current weight value of the gallium oxide crystal are recorded; Determining a standard weight change range and a current weight change range of the gallium oxide crystal according to a current position of the pulling axis and a current weight value of the gallium oxide crystal; The output power of the growth furnace is controlled based on the standard weight change amplitude and current weight change amplitude of the gallium oxide crystal under the predetermined thermocouple test temperature and furnace pressure value, and the seed crystal is pulled upward at the output power to perform equal diameter operation.

6. The method for controlling the growth of gallium oxide crystals according to claim 5, characterized in that: The process of controlling the output power of the growth furnace based on the standard weight change amplitude and the current weight change amplitude of the gallium oxide crystal specifically includes: Determining a theoretical pulling distance of the gallium oxide crystal based on the pulling speed of the gallium oxide crystal; When the sum of the standard weight change range and the preset increase rate variable value is greater than or equal to the current weight change range, and the difference between the standard weight change range and the preset increase rate variable value is less than or equal to the current weight change range; adjusting the output power of the growth furnace based on the theoretical pulling distance of the gallium oxide crystal; When the difference between the standard weight change range and the preset increase rate variable value is greater than the current weight change range; adjusting the output power of the growth furnace based on the initial position and theoretical pulling distance of the gallium oxide crystal; When the sum of the preset increase rate variable values ​​of the standard weight change range is less than the current weight change range; The output power of the growth furnace is adjusted based on the current position of the gallium oxide crystal and the theoretical pulling distance.

7. The method for controlling the growth of gallium oxide crystals according to claim 6, characterized in that: The process of adjusting the output power of the growth furnace based on the theoretical pulling distance of the gallium oxide crystal specifically includes: When the theoretical pulling distance is greater than the current position of the gallium oxide crystal, adjusting the output power of the growth furnace to a value having the same temperature drop rate as the growth furnace; When the theoretical pulling distance is less than or equal to the current position of the seed crystal, the magnitude relationship between the standard weight change range and the current weight change range is re-determined.

8. The method for controlling the growth of gallium oxide crystals according to claim 6, characterized in that: The process of adjusting the output power of the growth furnace based on the initial position and theoretical pulling distance of the gallium oxide crystal specifically includes: Determining whether the current equal diameter stage of the gallium oxide crystal is the first equal diameter stage; If the current equal diameter stage is not the first equal diameter stage of the gallium oxide crystal, a pause operation is performed for a preset time, the current pulling speed is reduced to 0, and the output power of the growth furnace is adjusted to a preset power; When the theoretical pulling distance of the gallium oxide crystal is greater than the current position of the gallium oxide crystal, adjusting the power of the growth furnace to a first preset power; When the theoretical pulling distance of the gallium oxide crystal is less than or equal to the current position of the gallium oxide crystal, the power of the growth furnace is adjusted to a second preset power.

9. The method for controlling the growth of gallium oxide crystals according to claim 6, characterized in that: The process of adjusting the output power of the growth furnace based on the initial position and theoretical pulling distance of the gallium oxide crystal specifically includes: When the current position of the gallium oxide crystal is greater than the sum of the theoretical pull-off distance and the preset distance, and the current weight change amplitude of the gallium oxide crystal is less than the preset pull-off rate, determining the pulling speed of the growth furnace, and setting the output power of the growth furnace based on the pulling speed; When the current position of the gallium oxide crystal is less than or equal to the sum of the theoretical pull-off distance and the preset distance, and the current weight change amplitude is greater than the theoretical increase rate, pausing the current equal diameter operation and setting the output power of the growth furnace to a third preset power; When the current position of the gallium oxide crystal is less than or equal to the sum of the theoretical pull-off distance and the preset distance, and the current weight change amplitude is less than the theoretical increase rate, the current pulling speed is set to the preset speed, and the output power of the growth furnace is determined based on the theoretical pulling distance of the gallium oxide crystal and the current position of the gallium oxide crystal.

10. A gallium oxide crystal growth device, characterized in that: include: A growth furnace for growing gallium oxide crystals, a human-machine interface (HMI) module and a PLC control module connected to the growth furnace; The human-machine HMI module is used to obtain growth control parameters and transmit the growth control parameters to the PLC control module; The PLC control module is used to output a growth control signal for the gallium oxide crystal in the growth furnace according to the received growth control parameters, and send the growth control signal to the growth furnace; The growth furnace is used to receive the growth control signal and perform corresponding control operations on the growth process of the gallium oxide crystal; The growth furnace comprises a hollow reaction chamber, a lifting shaft arranged in the reaction chamber, a temperature rise and fall controller and a weight sensor; The pulling axis is used to control the growth rate of the gallium oxide crystal according to the received growth control parameters; The temperature control controller is used to adjust the temperature in the reaction chamber according to the received temperature control instruction; The weight sensor is used to collect weight data of the gallium oxide crystals in the reaction chamber and transmit the weight data to the PLC control module.

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