Crystal pulling control method

Abstract

The invention discloses a crystal pulling control method, and belongs to the technical field of photovoltaics. The crystal pulling control method comprises the steps that under the condition that it is detected that a silicon material in a crucible is completely melted into molten liquid, the heating power is adjusted according to the feeding amount in the crucible, so that the liquid temperature of the molten liquid is adjusted; controlling the single crystal furnace to perform welding operation under the condition that the liquid temperature of the melt reaches the welding liquid temperature; and controlling the single crystal furnace to sequentially perform seeding operation, shouldering operation, shoulder rotation operation, equal-diameter operation and ending operation on the crystal under the condition of detecting that the welding is completed, so as to obtain the crystal bar. The production efficiency, the production quality and the production stability can be improved, and the labor cost is reduced.

Description

Technical Field

[0001] The present application belongs to the field of photovoltaic technology, and in particular, relates to a crystal pulling control method. Background Art

[0002] The crystal pulling process refers to the preparation of polycrystalline silicon raw materials into single crystal silicon rods, i.e. crystal rods. As a semiconductor material with excellent performance, crystal rods are widely used in integrated circuits, solar cells and other products.

[0003] However, the current crystal pulling process uses a manually operated single crystal furnace to pull crystals, which requires a large number of operators and a high level of technical skills, resulting in high labor costs, low production efficiency, and the inability to guarantee production quality and stability. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a crystal pulling control method, which can improve production efficiency, improve production quality and production stability, and reduce labor costs.

[0005] In a first aspect, the present application provides a crystal pulling control method, comprising:

[0006] When it is detected that the silicon material in the crucible is completely melted into a molten liquid, the heating power is adjusted according to the amount of material in the crucible to adjust the liquid temperature of the molten liquid;

[0007] When it is detected that the liquid temperature of the melt reaches the melting liquid temperature, the single crystal furnace is controlled to perform the melting operation;

[0008] When it is detected that the welding is completed, the single crystal furnace is controlled to perform seeding operation, shoulder release operation, shoulder rotation operation, equal diameter operation and finishing operation on the crystal in sequence to obtain a crystal rod.

[0009] According to the crystal pulling control method of the present application, the single crystal furnace is automatically controlled to perform welding operations, crystal seeding operations, shoulder release operations, shoulder rotation operations and equal diameter operations, thereby realizing automated crystal pulling, reducing the manual intervention rate, improving production efficiency, reducing the variability caused by manual operations, improving production quality and production stability, and reducing labor costs; and, according to the amount of material fed into the crucible, the heating power is adjusted to adjust the liquid temperature of the solution to the welding liquid temperature, thereby increasing the adjustment rate, improving the temperature control accuracy, and improving the welding quality.

[0010] According to an embodiment of the present application, when the completion of the fusion is detected, the single crystal furnace is controlled to sequentially perform a seeding operation, a shoulder release operation, a shoulder rotation operation, an equal diameter operation and a finishing operation on the crystal to obtain a crystal rod, including:

[0011] When the completion of the welding is detected, the heating power is adjusted to the seeding power to adjust the liquid temperature of the melt;

[0012] When it is detected that the liquid temperature of the melt reaches the seeding liquid temperature, controlling the single crystal furnace to perform a seeding operation on the crystal;

[0013] When it is detected that the length of the crystal reaches a first target length range and the seeding pulling speed reaches a target pulling speed range, controlling the single crystal furnace to perform a shoulder release operation on the crystal;

[0014] When it is detected that the diameter of the crystal reaches the first target diameter range, controlling the single crystal furnace to perform a shoulder rotation operation on the crystal;

[0015] When it is detected that the diameter of the crystal remains within the second target diameter range within the first target time length, controlling the single crystal furnace to perform a diameter-equalizing operation on the crystal;

[0016] When it is detected that the amount of remaining silicon material in the crucible reaches the target value, the single crystal furnace is controlled to perform a finishing operation on the crystal to obtain a crystal rod.

[0017] According to one embodiment of the present application, the method further includes:

[0018] During the seed crystal welding operation, the photoelectric control system is controlled to detect the aperture diameter of the seed crystal;

[0019] When it is detected that the aperture diameter of the seed crystal has contracted within the target range, it is determined that the welding is completed.

[0020] According to one embodiment of the present application, controlling the single crystal furnace to perform a seeding operation on the crystal includes:

[0021] Collect the current seeding image;

[0022] When it is detected within the second target time that the similarity between the convex point features of the current seeding image and the convex point features of the previous seeding image reaches the target similarity, the single crystal furnace is controlled to perform a seeding operation on the crystal.

[0023] According to one embodiment of the present application, the method further includes:

[0024] Determine the shoulder type;

[0025] During the shoulder release operation, at least one of the pot lifting rate, the heating power and the crystal pulling rate is adjusted according to the shoulder release shoulder type.

[0026] According to an embodiment of the present application, adjusting at least one of a pot lifting rate, a heating power and a crystal pulling rate according to the shoulder shape includes:

[0027] According to the shoulder type, the shoulder bottom angle is determined;

[0028] Calculating the actual diameter of the crystal according to the shoulder bottom angle and the actual height of the crystal;

[0029] At least one of the pot lifting rate, the heating power and the crystal pulling rate is adjusted according to the actual diameter of the crystal.

[0030] According to one embodiment of the present application, the method further includes:

[0031] During the equal diameter operation, if a crystal break is detected and the crystal is in a circulating section, the single crystal furnace is controlled to perform a finishing operation when it is detected that the amount of remaining silicon material in the crucible meets the finishing requirement;

[0032] After detecting that the finishing operation is completed, the required feeding amount is calculated according to the remaining silicon material amount in the crucible, and the single crystal furnace is controlled to perform the feeding operation according to the required feeding amount.

[0033] According to one embodiment of the present application, the method further includes:

[0034] During the equal diameter operation, if a crystal break is detected and the crystal is a finished segment, the amount of remaining silicon material in the crucible is detected;

[0035] If it is detected that the amount of remaining silicon material in the crucible is greater than the first amount of remaining material, the crystal is taken out and then the crystal is continued to be introduced;

[0036] If it is detected that the amount of remaining silicon material in the crucible is greater than the second amount of remaining material and less than the first amount of remaining material, the crystal is continuously pulled in equal diameters and the liquid temperature of the solution is controlled to increase;

[0037] If it is detected that the amount of remaining silicon material in the crucible is less than the second remaining material amount, the single crystal furnace is controlled to perform a shutdown operation.

[0038] According to one embodiment of the present application, after obtaining the crystal rod, the method further includes:

[0039] detecting quality data of the crystal ingot, and comparing the quality data of the crystal ingot with a quality index;

[0040] When it is detected that the quality data of the crystal rod does not meet the standard, an alarm is issued to the single crystal furnace, and the single crystal furnace is stopped.

[0041] According to one embodiment of the present application, before adjusting the heating power according to the amount of material in the crucible and the material power, the method further includes:

[0042] Control the single crystal furnace to perform vacuum operation;

[0043] When it is detected that the pressure in the single crystal furnace is less than the target pressure, controlling the single crystal furnace to perform a leak detection operation;

[0044] When it is detected that the leak rate in the single crystal furnace is less than the target leak rate, controlling the single crystal furnace to perform a pressure operation;

[0045] When it is detected that the duration of the pressurization operation of the single crystal furnace reaches the target duration, the single crystal furnace is controlled to perform a melting operation, a supplementary doping operation and a material adding operation.

[0046] According to one embodiment of the present application, a side wall of the single crystal furnace is provided with a feed port; controlling the single crystal furnace to perform a feeding operation includes:

[0047] The feeding device is controlled to add silicon material into the crucible of the single crystal furnace through the feeding port.

[0048] According to one embodiment of the present application, the feeding device includes a material storage box, a material guide cylinder connected to the material storage box, and a vibrator in contact with the material storage box;

[0049] The controlling feeding device adds silicon material into the crucible of the single crystal furnace through the feeding port, comprising:

[0050] Controlling the material guide cylinder to pass through the material feed port and extend to the top of the crucible;

[0051] The vibrator is controlled to vibrate so as to drive the silicon material in the material storage box to fall into the crucible through the material guide tube at a uniform speed.

[0052] The above one or more technical solutions in the embodiments of the present application have at least one of the following technical effects:

[0053] By automatically controlling the single crystal furnace to perform welding operations, crystal seeding operations, shoulder release operations, shoulder rotation operations and equal diameter operations, etc., automatic crystal pulling is achieved, the manual intervention rate is reduced, production efficiency is improved, the variability caused by manual operations is reduced, production quality and production stability are improved, and labor costs are reduced; moreover, the heating power is adjusted according to the amount of material fed into the crucible to adjust the liquid temperature of the solution to the welding liquid temperature, thereby increasing the adjustment rate, improving the temperature control accuracy, and improving the welding quality.

[0054] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0056] Figure 1 It is one of the flow charts of the crystal pulling control method provided in the embodiment of the present application;

[0057] Figure 2 This is the second flow chart of the crystal pulling control method provided in the embodiment of the present application. DETAILED DESCRIPTION

[0058] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0059] The crystal pulling control method provided in the embodiments of the present application is described below with reference to the accompanying drawings.

[0060] Figure 1 A schematic flow chart of a crystal pulling control method provided in an embodiment of the present application.

[0061] like Figure 1 As shown, the crystal pulling control method provided in the embodiment of the present application includes step 110, step 120 and step 130.

[0062] Step 110 : When it is detected that the silicon material in the crucible is completely melted into a molten liquid, the heating power is adjusted according to the amount of material in the crucible to adjust the liquid temperature of the molten liquid.

[0063] In some embodiments, before step 110, Figure 2 As shown, the single crystal furnace can be subjected to the processes of dismantling, cleaning and installing the furnace and hoisting and closing the furnace.

[0064] Among them, the furnace dismantling, cleaning and loading process includes: cleaning the single crystal furnace that has been shut down, namely cleaning the furnace cavity, the heat field and the pipeline, etc. After the cleaning is completed, the heat field is loaded into the furnace in sequence to complete the furnace dismantling, cleaning and loading process.

[0065] The process of hanging materials and closing the furnace includes: after completing the process of dismantling, cleaning and loading the furnace, hanging the quartz crucible containing raw polysilicon into the carbon-carbon crucible, and then rotating the furnace cover of the single crystal furnace to complete the furnace closing process.

[0066] After completing the material hanging and furnace closing processes, click the "one-click crystal pulling" button to start automatic crystal pulling.

[0067] In some embodiments, before step 110, Figure 2 As shown, the crystal pulling control method also includes: controlling the single crystal furnace to perform vacuum operation, leak detection operation, pressure operation, melting operation, supplementary doping operation and material adding operation.

[0068] In some embodiments, before adjusting the heating power according to the amount of material in the crucible in step 110, the crystal pulling control method further includes:

[0069] Control the single crystal furnace to perform vacuum operation;

[0070] When it is detected that the pressure in the single crystal furnace is less than the target pressure, the single crystal furnace is controlled to perform a leak detection operation;

[0071] When it is detected that the leak rate in the single crystal furnace is less than the target leak rate, the single crystal furnace is controlled to perform a pressure operation;

[0072] When it is detected that the duration of the pressurization operation of the single crystal furnace reaches the target duration, the single crystal furnace is controlled to perform melting operation, supplementary doping operation and material adding operation.

[0073] During the vacuuming operation, the main pump is automatically turned on. After a certain period of time (such as 2 minutes), the main pump ball valve is automatically opened to allow the main pump to vacuum the single crystal furnace. The pressure in the single crystal furnace is detected in real time. When it is detected that the pressure in the single crystal furnace is less than or equal to the target pressure (such as 20mTorr), it automatically jumps to the leak detection operation, otherwise it continues to vacuum.

[0074] During the leak detection operation, the leak detection rate in the single crystal furnace is detected. When the leak detection rate in the single crystal furnace is detected to be less than the target leak detection rate (such as 60mTorr·L / s), it automatically jumps to the pressure operation. Otherwise, an inert gas (such as argon) is introduced into the single crystal furnace to evacuate the vacuum, and the leak detection operation continues. When it is detected that the pressure in the single crystal furnace is less than or equal to the target pressure, and the leak detection rate in the single crystal furnace is less than the target leak detection rate, it automatically jumps to the pressure operation.

[0075] During the pressure operation, an inert gas (such as argon) can be introduced into the single crystal furnace. When it is detected that the duration of the pressure operation reaches the target duration (such as 3 minutes), it automatically jumps to the melting operation.

[0076] In the melting operation, the silicon material in the crucible is melted according to the melting formula table so that the silicon material in the crucible is completely melted into a molten liquid. It should be noted that the crucible is initially loaded with silicon material, and the melting operation is first performed on the silicon material initially loaded in the crucible. During the melting process or after the melting, a certain amount of impurity elements can be added to the solution to perform a supplementary doping operation. After the initial silicon material in the crucible is melted into a molten liquid, the single crystal furnace can be controlled to perform a feeding operation, and the melting operation and supplementary doping operation can be continued until the feed amount in the single crystal furnace reaches the required feed amount.

[0077] Among them, when it is detected that the melting time reaches the target melting time, or when it is detected that the solid-liquid ratio of the crucible liquid surface (that is, the ratio of unmelted solid silicon material on the crucible liquid surface to the melted liquid) reaches the target ratio, the single crystal furnace can be controlled to perform the feeding operation.

[0078] When it is detected that the silicon material in the crucible is completely melted into a molten liquid, the single crystal furnace can be controlled to pre-adjust the temperature so as to adjust the liquid temperature of the solution to the melting liquid temperature, so as to facilitate subsequent melting operations.

[0079] During temperature pre-adjustment, since the initial silicon material loaded in the crucible is fixed and the silicon material for each adding operation is fixed, the amount of material in the crucible can be determined based on the initial silicon material loaded in the crucible and the silicon material added subsequently. Different amounts of material in the crucible will directly affect the energy required during the heating process and the uniformity of heating. By using different heating powers, the liquid temperature of the solution can be adjusted to the melting liquid temperature as quickly as possible. If the amount of material in the crucible is large, the heating power can be large; if the amount of material in the crucible is small, the heating power can be small. It should be noted that the corresponding relationship between the amount of material in the crucible and the heating power can be determined through intelligent big data collection, so that the heating power can be accurately adjusted according to the amount of material in the crucible.

[0080] The related technology controls the heating power by detecting the solid-liquid ratio of the crucible liquid surface through images. If there are problems such as data transmission delay, the real-time response speed of the system will be affected, which will lead to inaccurate liquid temperature control and affect the subsequent welding quality. However, in the present embodiment, when pre-adjusting the temperature, the heating power is adjusted according to the amount of material in the crucible to adjust the liquid temperature of the solution to the welding liquid temperature as soon as possible, thereby increasing the adjustment rate, improving the temperature control accuracy, and improving the welding quality.

[0081] Step 120: When it is detected that the liquid temperature of the melt reaches the melting liquid temperature, the single crystal furnace is controlled to perform a melting operation.

[0082] After the liquid temperature of the solution reaches the melting temperature, the seed crystal melting operation can be automatically performed. The seed crystal is lowered into the solution to melt the seed crystal with the melt. The state of the melting process can be judged by the change in the aperture diameter of the seed crystal.

[0083] In some embodiments, the crystal pulling control method further includes:

[0084] During the welding operation, the photoelectric control system is controlled to detect the aperture diameter of the seed crystal;

[0085] When it is detected that the aperture diameter of the seed crystal has contracted within the target range, it is determined that the welding is completed.

[0086] During the welding process, the fine crystal is tested for temperature, and the unmelted seed crystal automatically descends to the original seed crystal position for welding. When the aperture diameter of the seed crystal is detected to shrink to the target range (such as 1.2-1.5mm) through the photoelectric control system, the welding is determined to be completed.

[0087] For the melting seed crystal, when the temperature of the solution reaches the target temperature range, the seed crystal is inserted down a certain distance (such as 2mm) to detect whether the aperture diameter of the seed crystal reaches the target diameter (such as 13mm). If not, when the temperature of the solution reaches the target temperature range, the seed crystal is inserted down again and the aperture diameter of the seed crystal is detected until the aperture diameter of the seed crystal reaches the target diameter. The maximum descending distance of the seed crystal is 10mm.

[0088] Step 130: When it is detected that the welding is completed, the single crystal furnace is controlled to perform seeding operation, shoulder release operation, shoulder rotation operation and equal diameter operation on the crystal in sequence to obtain a crystal rod.

[0089] In some embodiments, in step 130, when the completion of the fusion bonding is detected, the single crystal furnace is controlled to sequentially perform a seeding operation, a shoulder release operation, a shoulder rotation operation, an equal diameter operation, and a finishing operation on the crystal to obtain a crystal rod, including:

[0090] When the completion of the welding is detected, the heating power is adjusted to the seeding power to adjust the liquid temperature of the melt;

[0091] When it is detected that the liquid temperature of the melt reaches the seeding liquid temperature, the single crystal furnace is controlled to perform a seeding operation on the crystal;

[0092] When it is detected that the length of the crystal reaches the first target length range and the seeding pulling speed reaches the target pulling speed range, the single crystal furnace is controlled to perform a shoulder release operation on the crystal;

[0093] When it is detected that the diameter of the crystal reaches the first target diameter range, controlling the single crystal furnace to perform a shoulder rotation operation on the crystal;

[0094] When it is detected that the diameter of the crystal remains within the second target diameter range within the first target time length, controlling the single crystal furnace to perform a diameter-equalizing operation on the crystal;

[0095] When it is detected that the amount of remaining silicon material in the crucible reaches the target value, the single crystal furnace is controlled to perform finishing operations on the crystal to obtain a crystal rod.

[0096] After the welding is completed, the initial liquid temperature of the solution is C0, corresponding to the time T0, the required welding liquid temperature C1, and the seeding liquid temperature C2. Given the heating and cooling power P, after T1 = (|C0-C1|)*(10~15)-T0-(15~20)min, the liquid temperature of the solution is adjusted to the required welding liquid temperature C1. After T2 = (C1-C2)*(10~15)-T1-(15~20)min, given the seeding power P1, the liquid temperature of the solution is adjusted to the seeding liquid temperature C2. Stabilize for 20~30min to perform the seeding operation. Among them, the entire temperature adjustment process does not exceed 70min.

[0097] After the liquid temperature of the solution is stabilized at the seeding temperature, the single crystal furnace can be controlled to perform the seeding operation.

[0098] In some embodiments, controlling the single crystal furnace to perform a seeding operation on the crystal includes:

[0099] Collect the current seeding image;

[0100] When it is detected within the second target time that the similarity between the convex point features of the current seeding image and the convex point features of the previous seeding image reaches the target similarity, the single crystal furnace is controlled to perform a seeding operation on the crystal.

[0101] The seeding image in the process of making the current crystal rod is collected in real time. The convex features of the current seeding image are visually detected within the second target time (such as 120s). The convex features of the current seeding image are compared with the convex features of the seeding image in the process of making the previous crystal rod. If the comparison similarity reaches the target similarity (such as 80%), the single crystal furnace is controlled to automatically seed the crystal to achieve seeding automation.

[0102] During the seeding operation, the length of the crystal is detected in real time. When it is detected that the length of the crystal reaches the first target length range (such as 150-250mm), it is automatically determined whether the seeding pulling speed reaches the target pulling speed range (such as 260-320mm / h). If the seeding pulling speed reaches the target pulling speed range, it automatically jumps to the shoulder release operation. If the seeding pulling speed does not reach the target pulling speed range, the power correction is automatically performed. The correction logic is: seeding power after correction = (|actual seeding pulling speed-seeding pulling speed|) * (0.01-0.03) + seeding power. After the correction is completed, it automatically jumps to the shoulder release operation.

[0103] During the shoulder release operation, adjustments can be made according to the set shoulder release shoulder type.

[0104] In some embodiments, the crystal pulling control method further includes:

[0105] Determine the shoulder type;

[0106] During the shoulder release operation, at least one of the pot lifting rate, heating power and crystal pulling rate is adjusted in real time according to the shoulder type.

[0107] In some embodiments, at least one of a pot lifting rate, a heating power, and a crystal pulling rate is adjusted according to the shoulder type, including:

[0108] Determine the bottom angle of the shoulder according to the shoulder type;

[0109] Calculate the actual diameter of the crystal based on the shoulder bottom angle and the actual height of the crystal;

[0110] At least one of the pot lifting rate, the heating power and the crystal pulling rate is adjusted according to the actual diameter of the crystal.

[0111] The shoulder shape can be a pyramid. Set a fixed shoulder shape and determine the shoulder bottom angle Q. The shoulder logic is:

[0112] D 实际 =L 实际 / tanQ;

[0113] S 实际 =D 实际 2 / D 埚 2*2.33 / 2.53;

[0114] W 实际 =W 设定 -(|D 实际 -D 设定 |)*X W设定 ;

[0115] V 实际 =V 设定 +(D 实际 -D 设定 )*V 设定 *X V设定 .

[0116] Among them, D 实际 is the actual diameter of the crystal, L 实际 is the actual height of the crystal, S 实际 is the actual pot rise rate, D 埚 is the diameter of the crucible, V 设定 is the set crystal pulling rate, D 设定 is the set diameter of the crystal, W 设定 is the set heating power.

[0117] The related technology matches and adjusts the pot lifting rate, heating power and crystal pulling rate according to the process parameter formula table (such as Table 1) and the historical shoulder release growth record, which cannot be judged and controlled in advance, and cannot ensure the shoulder release survival rate. However, this embodiment can set a single variable control by itself, adjust at least one of the pot lifting rate, heating power and crystal pulling rate, and judge and control in advance according to the shoulder release shoulder type, reduce the release break rate, such as improving the shoulder release survival rate by 5%-8%.

[0118]

[0119] Table 1

[0120] When the diameter of the crystal reaches a first target diameter range (eg, 250-302 mm) and the shoulder release rate reaches a target rate value, the shoulder rotation operation can be triggered.

[0121] During the shoulder rotation operation, the growth direction of the crystal is changed so that the crystal grows vertically downward. After detecting that the diameter of the crystal remains within the second target diameter range for the first target time, that is, the diameter of the crystal has no tendency to increase, it automatically jumps to the equal diameter operation. It should be noted that during the shoulder release operation and shoulder rotation operation, if the crystal is disconnected, it returns to the temperature adjustment operation to perform the seeding operation.

[0122] During the equal diameter operation, the crystal grows longitudinally. As the length of the crystal increases, the amount of silicon material remaining in the crucible decreases. If the crystal is not broken, the process automatically jumps to the end operation when the amount of silicon material remaining in the crucible reaches the target value.

[0123] In some embodiments, the crystal pulling control method further includes:

[0124] During the equal diameter operation, if the crystal is detected to be broken and the crystal is in a circulating section, the single crystal furnace is controlled to perform the finishing operation when it is detected that the amount of remaining silicon material in the crucible meets the finishing requirements;

[0125] After it is detected that the finishing operation is completed, the required feeding amount is calculated according to the remaining silicon material amount in the crucible, and the single crystal furnace is controlled to perform the feeding operation according to the required feeding amount.

[0126] During the equal diameter operation, the broken bud detection is performed through CCD capture. If the crystal is detected to be broken and the crystal is a circulating segment, the remaining silicon material in the crucible is detected to see if it meets the finishing requirements. If it does, it automatically jumps to the finishing operation.

[0127] After the finishing operation is completed, the ingot is taken out and cooled to maintain pressure. The remaining silicon material in the crucible is calculated, and the amount of material required for re-feeding is automatically calculated and fed back to the central control system. The central control system sends instructions to the material preparation system for secondary feeding.

[0128] In some embodiments, the crystal pulling control method further includes:

[0129] During the equal diameter operation, if the crystal is detected to be broken and the crystal is a finished segment, the amount of remaining silicon material in the crucible is detected;

[0130] If it is detected that the amount of remaining silicon material in the crucible is greater than the first amount of remaining material, the crystal is taken out and then the crystal is continued to be introduced;

[0131] If it is detected that the amount of remaining silicon material in the crucible is greater than the second amount of remaining material and less than the first amount of remaining material, the crystal is continuously pulled in equal diameters, and the liquid temperature of the solution is controlled to increase;

[0132] If it is detected that the amount of remaining silicon material in the crucible is less than the second remaining material amount, the single crystal furnace is controlled to perform a shutdown operation.

[0133] During the equal-diameter operation, the broken bud detection is performed through CCD capture. If the crystal is detected to be broken and the crystal is in the finished section, the amount of remaining silicon material in the crucible is detected. If it is detected that the amount of remaining silicon material in the crucible is greater than the first remaining amount (such as 50-80kg), the crystal is taken out and the crystal is continued to be introduced; if it is detected that the amount of remaining silicon material in the crucible is greater than the second remaining amount (such as 30kg) and less than the first remaining amount, the crystal is continued to be equal-diameter pulled, and the liquid temperature of the solution is controlled to rise; if it is detected that the amount of remaining silicon material in the crucible is less than the second remaining amount, the single crystal furnace is controlled to stop the furnace operation to cool the furnace.

[0134] After the furnace is stopped, the system automatically determines the furnace start time based on the amount of silicon material remaining in the crucible. If the furnace is abnormal and the furnace is stewed, and there is a lot of silicon material remaining in the crucible, the furnace start time will be extended.

[0135] In some embodiments, after obtaining the crystal ingot, the crystal pulling control method further includes:

[0136] Detect the quality data of the crystal ingot and compare the quality data of the crystal ingot with the quality index;

[0137] When it is detected that the quality data of the crystal rod does not meet the standard, the single crystal furnace will be alarmed and the single crystal furnace will be stopped.

[0138] After the crystal rod is cooled, the AGV is controlled to send the crystal rod to the machining workshop for cutting, slicing, and quality data measurement. The quality data of the crystal rod is compared with the quality index. If the quality data of the crystal rod meets the quality index, it will flow normally; if the quality data of the crystal rod does not meet the quality index, the data will be fed back to the on-site central control system to alarm the abnormality and stop the furnace for processing.

[0139] In some embodiments, a side wall of the single crystal furnace is provided with a feed port. Controlling the single crystal furnace to perform a feed operation includes:

[0140] The feeding device is controlled to add silicon material into the crucible of the single crystal furnace through the feeding port.

[0141] The required amount of material is calculated and fed back to the central control system, which then distributes the task to the material preparation system for material addition or secondary addition. After the silicon material is loaded into the feeding device, it is transported to the single crystal furnace by the AGV trolley. There is a feeding port on the side wall of the single crystal furnace, and the feeding device adds the silicon material to the crucible through the feeding port.

[0142] In some embodiments, the feeding device includes a material storage box, a material guide cylinder connected to the material storage box, and a vibrator in contact with the material storage box. Controlling the feeding device to add silicon material to the crucible of the single crystal furnace through the feed port includes:

[0143] Control the material guide cylinder to pass through the feed opening and extend to the top of the crucible;

[0144] The vibrator is controlled to vibrate to drive the silicon material in the storage box to fall into the crucible at a uniform speed through the material guide tube.

[0145] After the feeding device is transported to the single crystal furnace, the material guide tube is inserted through the feeding port into the center of the crucible in the furnace. The feeding device is started, and the vibration device is started at the same time to drive the silicon material in the storage box to fall into the crucible at a uniform speed through the material guide tube to prevent the silicon material from falling and damaging the crucible.

[0146] The feed port in the related art is located at the top of the single crystal furnace, and the feeding can only be carried out after the crystal rod is taken out, which has a low feeding efficiency. However, the feed port in this embodiment is located on the side wall of the single crystal furnace, and after the finishing operation is completed, the feeding can be carried out without taking out the crystal rod, which effectively improves the feeding efficiency.

[0147] According to the crystal pulling control method provided in the embodiment of the present application, the single crystal furnace is automatically controlled to perform welding operations, crystal seeding operations, shoulder release operations, shoulder rotation operations and equal diameter operations, etc., thereby realizing automated crystal pulling, reducing the human intervention rate, improving production efficiency, and accurately controlling key parameters such as temperature, pressure and gas flow, thereby accelerating the crystal growth process and shortening the production cycle; automated crystal pulling ensures the consistency of production conditions, reduces the variability caused by manual operation, and makes the single crystal growth process more stable and the yield rate higher; automated control can accurately control the growth conditions, which helps to produce single crystal materials with better uniformity and fewer defects, thereby improving production quality; automated crystal pulling reduces dependence on manpower, reduces labor costs, and also reduces risks caused by manual operation errors. Loss or accident; single crystal growth usually needs to be carried out in a high temperature and high pressure environment. Automated crystal pulling can prevent workers from direct contact with these dangerous environments, improve the working environment, and enhance work safety; real-time monitoring of the production process and collection of large amounts of data for subsequent analysis will help optimize process parameters and improve production efficiency and product quality; automated production lines can quickly adjust production plans according to market needs and change the type or size of grown single crystals, thereby enhancing the company's flexibility and market competitiveness; automated crystal pulling can reduce energy consumption, reduce production costs, and improve production efficiency by optimizing operating procedures and precise control; automated single crystal furnaces integrate artificial intelligence technology, which can perform self-diagnosis and fault warning, reduce downtime, and improve equipment availability and maintenance efficiency.

[0148] The terms "first", "second", etc. in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of the same type, and the number of objects is not limited. For example, the first object can be one or more.

[0149] In the description of the present application, “plurality” means two or more.

[0150] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0151] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A crystal pulling control method, characterized in that: The method comprises: When it is detected that the silicon material in the crucible is completely melted into a molten liquid, the heating power is adjusted according to the amount of material in the crucible to adjust the liquid temperature of the molten liquid; When it is detected that the liquid temperature of the melt reaches the melting liquid temperature, the single crystal furnace is controlled to perform the melting operation; When it is detected that the welding is completed, the single crystal furnace is controlled to perform seeding operation, shoulder release operation, shoulder rotation operation, equal diameter operation and finishing operation on the crystal in sequence to obtain a crystal rod.

2. The crystal pulling control method according to claim 1, characterized in that: When the completion of the fusion bonding is detected, the single crystal furnace is controlled to sequentially perform a seeding operation, a shoulder release operation, a shoulder rotation operation, an equal diameter operation and a finishing operation on the crystal to obtain a crystal rod, including: When the completion of the welding is detected, the heating power is adjusted to the seeding power to adjust the liquid temperature of the melt; When it is detected that the liquid temperature of the melt reaches the seeding liquid temperature, controlling the single crystal furnace to perform a seeding operation on the crystal; When it is detected that the length of the crystal reaches a first target length range and the seeding pulling speed reaches a target pulling speed range, controlling the single crystal furnace to perform a shoulder release operation on the crystal; When it is detected that the diameter of the crystal reaches the first target diameter range, controlling the single crystal furnace to perform a shoulder rotation operation on the crystal; When it is detected that the diameter of the crystal remains within the second target diameter range within the first target time length, controlling the single crystal furnace to perform a diameter-equalizing operation on the crystal; When it is detected that the amount of remaining silicon material in the crucible reaches the target value, the single crystal furnace is controlled to perform a finishing operation on the crystal to obtain a crystal rod.

3. The crystal pulling control method according to claim 1, characterized in that: The method further comprises: During the welding operation, the photoelectric control system is controlled to detect the aperture diameter of the seed crystal; When it is detected that the aperture diameter of the seed crystal has contracted within the target range, it is determined that the welding is completed.

4. The crystal pulling control method according to claim 2, characterized in that: The controlling the single crystal furnace to perform a seeding operation on the crystal comprises: Collect the current seeding image; When it is detected within the second target time that the similarity between the convex point features of the current seeding image and the convex point features of the previous seeding image reaches the target similarity, the single crystal furnace is controlled to perform a seeding operation on the crystal.

5. The crystal pulling control method according to claim 1, characterized in that: The method further comprises: Determine the shoulder type; During the shoulder release operation, at least one of the pot lifting rate, the heating power and the crystal pulling rate is adjusted according to the shoulder release shoulder type.

6. The crystal pulling control method according to claim 5, characterized in that: The step of adjusting at least one of a pot lifting rate, a heating power and a crystal pulling rate according to the shoulder shape comprises: According to the shoulder type, the shoulder bottom angle is determined; Calculating the actual diameter of the crystal according to the shoulder bottom angle and the actual height of the crystal; At least one of the pot lifting rate, the heating power and the crystal pulling rate is adjusted according to the actual diameter of the crystal.

7. The crystal pulling control method according to claim 1, characterized in that: The method further comprises: During the equal diameter operation, if a crystal break is detected and the crystal is in a circulating section, the single crystal furnace is controlled to perform a finishing operation when it is detected that the amount of remaining silicon material in the crucible meets the finishing requirement; After detecting that the finishing operation is completed, the required feeding amount is calculated according to the remaining silicon material amount in the crucible, and the single crystal furnace is controlled to perform the feeding operation according to the required feeding amount.

8. The crystal pulling control method according to claim 1, characterized in that: The method further comprises: During the equal diameter operation, if a crystal break is detected and the crystal is a finished segment, the amount of remaining silicon material in the crucible is detected; If it is detected that the amount of remaining silicon material in the crucible is greater than the first amount of remaining material, the crystal is taken out and then the crystal is continued to be introduced; If it is detected that the amount of remaining silicon material in the crucible is greater than the second amount of remaining material and less than the first amount of remaining material, the crystal is continuously pulled in equal diameters and the liquid temperature of the solution is controlled to increase; If it is detected that the amount of remaining silicon material in the crucible is less than the second remaining material amount, the single crystal furnace is controlled to perform a shutdown operation.

9. The crystal pulling control method according to claim 1, characterized in that: After obtaining the crystal rod, the method further includes: detecting quality data of the crystal ingot, and comparing the quality data of the crystal ingot with a quality index; When it is detected that the quality data of the crystal rod does not meet the standard, an alarm is issued to the single crystal furnace, and the single crystal furnace is stopped.

10. The crystal pulling control method according to claim 1, characterized in that: Before adjusting the heating power according to the amount of material in the crucible and the material processing power, the method further includes: Control the single crystal furnace to perform vacuum operation; When it is detected that the pressure in the single crystal furnace is less than the target pressure, controlling the single crystal furnace to perform a leak detection operation; When it is detected that the leak rate in the single crystal furnace is less than the target leak rate, controlling the single crystal furnace to perform a pressure operation; When it is detected that the duration of the pressurization operation of the single crystal furnace reaches the target duration, the single crystal furnace is controlled to perform a melting operation, a supplementary doping operation and a material adding operation.

11. The crystal pulling control method according to claim 7 or 10, characterized in that: The side wall of the single crystal furnace is provided with a feeding port; controlling the single crystal furnace to perform a feeding operation includes: The feeding device is controlled to add silicon material into the crucible of the single crystal furnace through the feeding port.

12. The crystal pulling control method according to claim 11, characterized in that: The feeding device comprises a material storage box, a material guide cylinder connected to the material storage box, and a vibrator in contact with the material storage box; The controlling feeding device adds silicon material into the crucible of the single crystal furnace through the feeding port, comprising: Controlling the material guide cylinder to pass through the material feed port and extend to the top of the crucible; The vibrator is controlled to vibrate so as to drive the silicon material in the material storage box to fall into the crucible through the material guide tube at a uniform speed.

Images