A method for detecting automatic power increase of fractional crystallization

Abstract

This invention provides a method for detecting automatic power increase during segment crystallization. The steps are as follows: capturing images of the segment crystallization process using a visual inspection system; receiving the images of the segment crystallization process and performing logical judgments, outputting results, and executing a power increase action. The beneficial effects of this invention are: newly developed functions; independently developed segment crystallization power increase recognition logic and acquisition cycle; judgment using a machine perspective instead of a human perspective, improving recognition accuracy, enhancing furnace automation efficiency, and strengthening equipment automation; saving material processing time and improving time utilization, reducing the need for continuous on-site inspections by operators, improving personnel work efficiency, and significantly reducing the skill requirements for operators, thus strengthening industry competitiveness and providing a unified execution standard for segment crystallization power increase; effectively reducing the risk of breaking the quartz crucible due to excessive crystal volume, and adapting to various thermal field structures, achieving unified execution of repeated feeding.

Description

Technical Field

[0001] This invention belongs to the field of solar Czochralski silicon single crystal manufacturing and Czochralski semiconductor silicon single crystal single machine manufacturing equipment, and in particular relates to a detection method for automatic power increase of segment crystallization. Background Technology

[0002] When producing single-crystal silicon using the Czochralski method, after a certain length of uniform diameter, a section needs to be removed and re-fed. At this time, liquid crystallization is required in the furnace to prevent liquid from splashing due to the impact of the material block during the feeding process and sticking to the graphite parts, which would make subsequent crystallization difficult. In addition, the crystallization area cannot be too large to prevent the volume from increasing due to liquid crystallization in the furnace, which could cause the quartz crucible to crack.

[0003] With the gradual implementation of vision systems, in order to accelerate the realization of intelligent crystal pulling, we need to refine the manual judgment process and replace manual visual judgment with a visual image acquisition model. This will enhance the automation level of the equipment, improve the work efficiency of personnel, and at the same time greatly reduce the skill requirements of operators, thereby strengthening industry competitiveness.

[0004] Under the current mode, due to differences in the thermal field, the liquid crystallization area is inconsistent within the same single crystal extraction time. Some furnaces experience crystallization failure that breaks the quartz crucible. At the same time, some furnaces have excessively high temperatures that prevent crystallization, requiring personnel to monitor and adjust, which wastes manpower. In addition, the lack of preheating leads to increased working hours and waste of resources. Summary of the Invention

[0005] The problem this invention aims to solve is to provide a detection method for automatic power increase during segment crystallization. This method uses a visual image acquisition model to replace manual visual judgment, and is applicable to visual judgment and detection of the refeeding time point during segment crystallization. It is applicable to different thermal field structures, realizes a unified execution standard for refeeding, enhances the automation level of the equipment, and accelerates the automation process.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a detection method for automatic power enhancement of segment crystallization, the steps of which are as follows:

[0007] Images of the segment crystallization process are captured using a visual inspection system;

[0008] The server receives the image of the segment crystallization process, performs logical judgment, outputs the result, and executes the power increase action.

[0009] Furthermore, the segment crystallization process image starts from the set time of the segment crystallization process and ends when the re-processing step begins.

[0010] Furthermore, the set time is 60-70 minutes. After the set time for the segment crystallization process, the visual detection system begins to capture images of the segment crystallization process and transmits the images to the server.

[0011] Furthermore, in the step of the server receiving the segmented crystallization image and performing logical judgment, the server extracts the pixels of the crystallization region in the segmented crystallization process image and calculates the ratio of the area of ​​the crystallization region to the area of ​​the capture region of the visual detection system based on the image.

[0012] Furthermore, when the ratio is not less than the set threshold, the power is increased and a heat preservation operation is performed to carry out the re-injection step.

[0013] Furthermore, when the ratio is less than the set threshold, the segment crystallization process image continues to be captured.

[0014] Furthermore, the set threshold is 0.6.

[0015] Furthermore, in the step of capturing images of the segment crystallization process using a visual inspection system, an image of the segment crystallization process is acquired at regular intervals based on the change in time.

[0016] Furthermore, the time change is greater than 1 second.

[0017] Furthermore, the visual inspection system transmits images of the segment crystallization process to the server in real time for logical judgment and outputs the judgment result.

[0018] The above technical solution has the following beneficial effects:

[0019] 1. Newly developed function: Independently developed segment crystallization power identification logic and acquisition cycle, which uses machine perspective to replace human perspective for judgment, improves identification accuracy, enhances furnace automation efficiency, and strengthens equipment automation level;

[0020] 2. It saves material processing time and improves the utilization rate of working time, reduces the need for on-site operators to conduct continuous inspections, improves personnel work efficiency, and greatly reduces the skill level requirements of operators, thereby enhancing industry competitiveness and providing a unified standard for improving the efficiency of crystallization.

[0021] 3. It can effectively reduce the risk of breaking the quartz crucible due to excessive crystal volume, and is compatible with various thermal field structures, realizing the unified execution of repeated feeding. Attached Figure Description

[0022] Figure 1 This is a flowchart of one embodiment of the present invention. Detailed Implementation

[0023] The present invention will be further described below with reference to embodiments and accompanying drawings:

[0024] During the process of taking sections and feeding them again after a certain length of equal diameter, liquid crystallization is required in the furnace. This is to prevent liquid from splashing due to the impact of the material blocks during the feeding process and sticking to the graphite parts, which would make subsequent crystallization difficult. In addition, the crystallization area should not be too large to prevent the volume from increasing due to liquid crystallization in the furnace, which could cause the quartz crucible to crack. Figure 1 The diagram illustrates a logic flowchart of one embodiment of the present invention. In this embodiment, the current manual judgment of the time node for re-feeding after a certain length of equal diameter single crystal silicon is replaced by visual judgment. This enables precise control of the feeding node, accelerates intelligent crystal pulling, strengthens the automation process, and provides a unified execution standard for increasing the power of segment crystallization.

[0025] In one embodiment of the present invention, such as Figure 1 As shown, a detection method for automatic power enhancement in segment crystallization is described, and the detection method is as follows:

[0026] S1: Capture images of the segment crystallization process using a visual inspection system.

[0027] In this embodiment, a visual inspection system continuously captures images of the segment crystallization process. This system is positioned on one side of the furnace and captures images of the segment crystallization process within its field of view. The field of view of this visual image acquisition system is a set value, adjusted according to the different thermal field structures. Therefore, the position of the visual inspection system needs to be pre-set before image capture. This ensures that when performing logical judgments on the segment crystallization process images captured by the visual inspection system, the judgment results can intuitively and in real-time reflect the actual process, matching the actual process. Consequently, logical judgments on the segment crystallization process images can be directly performed, and the output judgment result allows for the next process step, enhancing equipment automation and accelerating intelligent crystal pulling. Simultaneously, the set position of the visual image acquisition system changes with the thermal field structure, ensuring that logical judgment conditions corresponding to the actual construction appear in the field of view detection.

[0028] S2: The server receives images of the segment crystallization process.

[0029] Specifically, the images of the segment crystallization process captured by the visual inspection system are transmitted to the server, where the server processes and makes logical judgments on the acquired images of the segment crystallization process.

[0030] In this embodiment, the visual inspection system is a CCD camera. It is conceivable that the visual inspection system is not limited to the CCD camera mentioned in this embodiment.

[0031] The entire detection and identification process is the segment crystallization step, also known as the isolation step. The process of capturing images of the segment crystallization process begins after a set time from the start of the segment crystallization process and ends when the reprocessing step begins. The set time is 60-70 minutes.

[0032] In this embodiment, the image capture and transmission command for the crystallization process begins 70 minutes after the segment crystallization process starts. Simultaneously, the server begins synchronous detection. The purpose of this waiting period is to ensure that if the crystal rod is removed after reaching a certain length, the large temperature difference between the inside and outside of the furnace could cause it to crack. In actual operation, the temperature of the crystal rod needs to be gradually reduced before removal. During this process, the power needs to be reduced to allow liquid crystallization to occur inside the crucible. This prevents liquid splashing during subsequent refeeding due to material impact, and the crystallization area should not be too large to prevent the increased volume of liquid crystals inside the furnace from cracking the quartz crucible. Therefore, the capture and transmission commands begin 70 minutes after the segment crystallization process, with synchronous detection.

[0033] In another embodiment of the present invention, the image of the segment crystallization process is captured and the image transmission command is executed 60 minutes after the segment crystallization process begins, and the server starts synchronous detection at the same time.

[0034] It is conceivable that the set time can be appropriately adjusted according to the actual segment crystallization process, such as adjusting the crystallization power, and appropriately increasing or decreasing the set time, and is not limited to the values ​​in this embodiment.

[0035] During image capture, the vision inspection system continuously captures images of the segment crystallization process, acquiring one image at regular intervals and transmitting it to the server in real time for image processing and logical judgment. Since this interval is greater than 1 second, in this embodiment, the vision inspection system captures one image every 3 seconds and transmits it to the server in real time. This avoids increasing bandwidth load and straining the server's capacity if images are transmitted too quickly. Considering all factors, the image transmission cycle for segment crystallization is set at one image every 3 seconds. It can be assumed that the image acquisition and transmission cycles of the vision inspection system can be adjusted according to the thermal field structure and the segment crystallization process, and are not limited to the values ​​in this embodiment.

[0036] During the segment crystallization process, the surface of the silicon solution is monitored, and images of the surface are acquired in real time to observe changes in the surface at each time interval, so as to obtain an image of the appropriate crystallization ratio at the first moment. In this embodiment, an image is acquired at every time interval. As the segment crystallization process proceeds, the first image is acquired, the second image is acquired after one time interval, and so on. There is a time interval between the acquisition of two adjacent surface images, and the two adjacent time intervals can be the same or different. It can be imagined that other acquisition methods can be selected according to actual needs, and no specific requirements are made here.

[0037] S3: The server performs image processing and logical judgment on the image of the segment crystallization process, outputs the judgment result, and executes the power increase action.

[0038] Specifically, when the server receives the image of the segment crystallization process, it can detect and output the judgment result in real time. According to the process cycle, an image of the segment crystallization process can be collected every 3 seconds and transmitted to the server in real time for logical judgment. One judgment result is output for each image.

[0039] The server extracts pixels from the crystallization region in the segment crystallization process image. Based on this image, it calculates the ratio of the crystallization region area to the area captured by the visual inspection system's field of view. When this ratio is not less than a set threshold, it automatically increases the power and performs a heat preservation operation, while simultaneously performing a rapid re-entry step. When the ratio is less than the set threshold, it continues to capture images of the segment crystallization process. In this embodiment, the set threshold is 0.6, meaning the ratio of the crystallization region area to the area captured by the visual inspection system's field of view is not less than 0.6.

[0040] It is conceivable that the threshold values ​​set by the visual image acquisition system will vary depending on the setting angle, the height of the thermal field, and the structure of the thermal field. In the actual crystallization process, the threshold values ​​can be adjusted in a timely manner according to the speed of the process steps and the cooling of the crystal rod.

[0041] Specifically, during the segment crystallization process, the silicon rod is slowly cooled while the power is reduced, causing the liquid in the crucible to crystallize. As the volume of the crystals in the crucible gradually increases, the number of crystals within the field of view of the vision inspection system also increases. The captured images of the segment crystallization process are processed by a server, which analyzes the pixels to calculate the ratio of the crystallized area to the area within the field of view captured by the vision inspection system. This provides a visual representation of the crystallization situation on the surface of the liquid in the crucible. If the ratio of the crystallized area within the field of view to the area within the field of view does not meet a set threshold, the process continues to capture images of the segment crystallization process until the ratio is no less than the set threshold. At this point, the power is automatically increased to a certain value for heat preservation, enabling rapid reprocessing. This method effectively avoids the shortcomings of existing methods and improves time utilization. The power increase to a certain value can be determined and adjusted based on the crystal pulling power and the segment crystallization power. In actual processes, the power of both the main heater and the auxiliary heater is increased. Typically, the power of the main heater is increased to the crystal pulling power plus 10 kW, and the power of the auxiliary heater is increased to 20 kW. The boosting power of the main heater and auxiliary heater varies depending on the actual process flow and is not limited to the values ​​in this embodiment.

[0042] By replacing the human perspective with a machine perspective, the condition of the crystallization liquid level in the crucible is monitored in real time. This provides a unified standard for the production of crystallization power, effectively reducing the risk of the quartz crucible breaking due to excessive crystal volume. It is also compatible with various thermal field structures, enabling unified execution of repeated feeding.

[0043] The embodiments of the present invention have been described in detail above, but the content described is only a preferred embodiment of the present invention and should not be considered as limiting the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the patent coverage of the present invention.

Claims

1. A detection method for automatic power enhancement of segment crystallization, characterized in that, The steps are as follows: Images of the segment crystallization process are captured using a visual inspection system; The server receives the image of the segment crystallization process, performs logical judgment, outputs the result, and performs a power increase action. The server extracts the pixels of the crystallization area in the image of the segment crystallization process and calculates the ratio of the area of ​​the crystallization area to the area captured by the visual detection system based on the image. When the ratio is not less than the set threshold, the power is increased and a heat preservation operation is performed to carry out the re-energization step. When the ratio is less than a set threshold, continue to capture images of the segment crystallization process.

2. The detection method for automatic power enhancement of segment crystallization according to claim 1, characterized in that: The segment crystallization process image starts from the set time of the segment crystallization process and ends when the re-processing step begins.

3. The detection method for automatic power enhancement of segment crystallization according to claim 2, characterized in that: The set time is 60-70 minutes. After the set time for the segment crystallization process, the visual detection system starts capturing images of the segment crystallization process and transmits the images to the server.

4. The detection method for automatic power enhancement of segment crystallization according to claim 1, characterized in that: The set threshold is 0.

6.

5. The detection method for automatic power enhancement of segment crystallization according to claim 1, characterized in that: In the step of capturing images of the segment crystallization process using a visual inspection system, an image of the segment crystallization process is obtained at regular intervals based on the change in time.

6. The detection method for automatic power enhancement of segment crystallization according to claim 5, characterized in that: The time change is greater than 1 second.

7. The method according to claim 6, wherein the method is characterized by: The visual inspection system transmits images of the segment crystallization process to the server in real time for logical judgment and outputs the judgment result.

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