TW202305201A - Monocrystal diameter control method and device and monocrystalline silicon crystal pulling furnace - Google Patents

Abstract

The invention provides a single crystal diameter control method and device and a monocrystalline silicon crystal pulling furnace, and belongs to the technical field of semiconductors. The single crystal diameter control device comprises a diameter detection module which is used for carrying out image sampling on the junction of the polycrystal melt and the crystal to obtain an original image, carrying out binarization processing on the original image to obtain a black-and-white image, calculating the area ratio of a white region to a black region in the black-and-white image, and calculating the area ratio of the white region to the black region in the black-and-white image; obtaining a diameter data value of the crystal according to the area proportion; and the control module is used for comparing the diameter data value with a preset diameter data value, and controlling the crystal pulling speed of the seed crystal pulling structure and/or the power of the heater according to a comparison result. According to the invention, the diameter of the crystal in the crystal generation process can be monitored, and the stability and controllability of the crystal quality are ensured.

Description

Single crystal diameter control method and device, single crystal silicon crystal pulling furnace

The invention belongs to the technical field of semiconductors, in particular to a single crystal diameter control method and device, and a single crystal silicon crystal pulling furnace.

Monocrystalline silicon, as a semiconductor material, is generally used in the manufacture of integrated circuits and other electronic components. In the process of preparing silicon single crystal, the seed crystal with smaller diameter is immersed in silicon melt, and a section of fine crystal with smaller diameter is grown by seeding to discharge dislocations to achieve the purpose of growing zero dislocation crystal. After that, the shouldering process will be used to make the crystal grow from a fine crystal to the target diameter, and then the crystal of the required size will be obtained through equal-diameter growth. Finally, the final step will separate the crystal rod from the liquid surface to obtain a complete crystal.

The equal diameter process is an extremely critical step in the crystal growth process, and it is also the key to ensuring crystal quality and yield. The diameter of the crystal is the premise to ensure the stability of the crystal growth and the guarantee of the product yield; the crystal diameter automatic control device is the key to ensure the automatic control of the diameter during the crystal growth process; currently, optical pyrometer sensors and charge-coupled devices are mainly used (Charge Coupled Device, CCD) optical camera is used to detect the crystal diameter, and the former is widely used in complex thermal field structure systems due to its advantages such as a smaller viewing angle of light and less interference of heated field components; the crystal diameter The working principle of the automatic control device is: through the optical sensor to monitor the brightness value of the aperture generated during the crystal growth process, and to monitor the position of the sensor for diameter control; simply speaking, through a fixed position (with the target diameter of the crystal Corresponding) sensor monitoring to feed back the change information of the crystal diameter. However, in the actual production process, with the change of the crystal length and the change of the internal structure of the thermal field, the aperture signal value at the crystal and liquid surface will change greatly, mainly because the aperture brightness value collected by the sensor In fact, the meniscus formed by the surface tension at the intersection of the crystal and the liquid surface forms a certain bright aperture by virtue of the optical reflection of the melt and the inner wall of the quartz crucible or other thermal field components; within the monitoring range of the diameter monitoring sensor On the one hand, the change of the brightness value of the aperture is due to the fluctuation of the actual diameter, and on the other hand, it is due to the change of the internal brightness of the light source, that is, the thermal field, so that the light value reflected by the meniscus changes; The main reason for the change of internal brightness is that during the actual growth process of the crystal, parameters such as the amount of remaining molten liquid in the crucible, the exposed area of the inner wall of the crucible, the power of the heater, and the distance between the liquid level and the guide tube during the growth process will all be affected. As the crystal grows correspondingly, the light value reflected to the sensor through the meniscus will also change greatly. In this case, it will greatly affect the control of the diameter of the device and ultimately affect the growth rate and the product. quality.

The technical problem to be solved by the present invention is to provide a single crystal diameter control method and device, and a single crystal silicon crystal pulling furnace, which can monitor the crystal diameter during the crystal formation process and ensure the stability and controllability of the crystal quality.

In order to solve the above technical problems, embodiments of the present invention provide technical solutions as follows: On the one hand, an embodiment of the present invention provides a single crystal diameter control device, which is applied to a single crystal silicon crystal pulling furnace. The single crystal silicon crystal pulling furnace includes a furnace body, a crucible and a heater are arranged in the furnace body, and a furnace located above the crucible Seed crystal pulling structure, the crucible is used to contain polycrystalline melt, and the single crystal diameter control device includes: The diameter detection module is used to sample the image at the junction of the polycrystalline melt and the crystal to obtain the original image, perform binarization on the original image to obtain a black and white image, and calculate the black and white image The area ratio of the white area to the black area, according to the area ratio, the diameter data value of the crystal is obtained; The control module is used to compare the diameter data value with a preset diameter data value, and control the crystal pulling speed of the seed crystal pulling structure and/or the power of the heater according to the comparison result.

In some embodiments, the control module is specifically used to increase the crystal pulling speed of the seed crystal pulling structure and/or the power of the heater when the diameter data value is greater than the preset diameter data value; When the data value is less than the predetermined diameter data value, reduce the crystal pulling speed of the seed crystal pulling structure and/or the power of the heater.

In some embodiments, also include: a guide rail disposed above the crucible; The diameter detecting module is arranged on the guide rail and can move along the guide rail.

In some embodiments, the diameter detection module includes: The camera unit is used to sample the image at the junction of the polycrystalline melt and the crystal to obtain an original image; The calculation unit is used to perform binarization processing on the original image to obtain a black and white image, and calculate the area ratio L between the white area and the black area in the black and white image, L=S1/S2, wherein S1 is the area of the white area , S2 is the area of the black area; The correction unit is used to correct the area ratio by using a correction coefficient to obtain the diameter data value.

The embodiment of the present invention also provides a single crystal silicon crystal pulling furnace, which includes a furnace body, a crucible, a heater, and a seed crystal pulling structure located above the crucible. The liquid also includes the single crystal diameter control device as described above.

The embodiment of the present invention also provides a single crystal diameter control method, which is applied to a single crystal silicon crystal pulling furnace. The single crystal silicon crystal pulling furnace includes a furnace body, a crucible and a heater are arranged in the furnace body, and a Seed crystal pulling structure, the crucible is used to contain polycrystalline melt, and the single crystal diameter control method includes: Sampling the image at the junction of the polycrystalline melt and the crystal to obtain the original image, performing binarization on the original image to obtain a black and white image, and calculating the area of the white area and the black area in the black and white image Ratio, the diameter data value of the crystal is obtained according to the area ratio; Comparing the diameter data value with a preset diameter data value, and controlling the crystal pulling speed of the seed crystal pulling structure and/or the power of the heater according to the comparison result.

In some embodiments, the method specifically includes: When the diameter data value is greater than the preset diameter data value, increase the crystal pulling speed of the seed crystal pulling structure and/or the power of the heater; when the diameter data value is smaller than the preset diameter data value, decrease The crystal pulling speed of the seed crystal pulling structure and/or the power of the heater.

In some embodiments, obtaining the diameter data value of the crystal according to the area ratio includes: The area ratio is corrected by the correction coefficient to obtain the diameter data value.

An embodiment of the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for controlling the diameter of a single crystal as described above are implemented.

Embodiments of the present invention have the following beneficial effects: In the above scheme, by monitoring the junction of the polycrystalline melt and the crystal, the diameter of the crystal during the crystal formation process can be monitored, and the crystal pulling speed and/or heater power of the seed crystal pulling structure can be adjusted in real time, so that The diameter of the crystal can reach the target diameter. This embodiment can ensure the authenticity of the crystal diameter obtained during the crystal growth process, ensure the stability of the crystal pulling speed, and improve the stability and controllability of the crystal quality.

In order for Ligui examiners to understand the technical characteristics, content and advantages of the present invention and the effects it can achieve, the present invention is hereby combined with the accompanying drawings and appendices, and is described in detail in the form of embodiments as follows, and the drawings used therein , the purpose of which is only for illustration and auxiliary instructions, and not necessarily the true proportion and precise configuration of the present invention after implementation, so it should not be interpreted based on the proportion and configuration relationship of the attached drawings, and limit the application of the present invention in actual implementation The scope is described first.

In the description of the embodiments of the present invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical" , "horizontal", "top", "bottom", "inner", "outer" and other indicated orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description , rather than indicating or implying that the device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and thus should not be construed as limiting the invention.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of said features. In the description of the embodiments of the present invention, "plurality" means two or more, unless otherwise specifically defined.

Embodiments of the present invention provide a single crystal diameter control method and device, and a single crystal silicon crystal pulling furnace, which can monitor the crystal diameter during the crystal generation process and ensure the stability and controllability of the crystal quality.

An embodiment of the present invention provides a single crystal diameter control device, which is applied to a single crystal silicon crystal pulling furnace. The single crystal silicon crystal pulling furnace includes a furnace body. As shown in FIG. 1, a crucible 30 and a heater (not shown in the figure) are arranged in the furnace body shown), and a seed crystal pulling structure (not shown) located above the crucible 30, the crucible 30 is used to contain the polycrystalline melt 40, and the single crystal diameter control device 10 includes: The diameter detection module is used to sample the image at the junction 60 of the polycrystalline melt 40 and the crystal 50 to obtain an original image, perform binarization on the original image to obtain a black and white image, and calculate the black and white image. The area ratio of the white area to the black area in the image, and the diameter data value of the crystal is obtained according to the area ratio; The control module is used to compare the diameter data value with a preset diameter data value, and control the crystal pulling speed of the seed crystal pulling structure and/or the power of the heater according to the comparison result.

In this embodiment, by monitoring the junction of the polycrystalline melt and the crystal, the diameter of the crystal during crystal formation can be monitored, and the crystal pulling speed and/or heater power of the seed crystal pulling structure can be adjusted in real time, The diameter of the crystal can reach the target diameter. This embodiment can ensure the authenticity of the crystal diameter obtained during the crystal growth process, ensure the stability of the crystal pulling speed, and improve the stability and controllability of the crystal quality.

During the crystal pulling process, polysilicon is put into the crucible 30 and heated and melted to become a polycrystalline melt 40, and a crystal with a specific crystal orientation is fixed at the lower end of the seed chuck structure. When pulling a single crystal silicon rod, first The crystal is welded with the polycrystalline melt, starting to enter the seeding stage; then by adjusting the temperature of the polycrystalline molten liquid, the upward lifting speed of the crystal, etc., the monocrystalline silicon continues to grow through the shoulder laying stage and the shoulder turning stage, and finally drawn out of monocrystalline silicon rods. Among them, the guide tube 20 is used to separate the temperature at the liquid surface from the surrounding environment of the ingot, so as to ensure a suitable crystal growth temperature gradient; the crucible 30 can be made of materials such as quartz or dock, and the inner wall is relatively smooth, with certain light reflection Function: the crystal edge 501 (including the protruding crystal lines) of the grown crystal 50 is welded to the polycrystalline melt 40 .

During the crystal growth process, at the junction 60 of the crystal 50 and the polycrystalline melt 40, the solid-liquid surface forms a meniscus structure due to the surface tension of the melt. The lunar surface structure will emit light with a brightness higher than that of the surrounding area, which is called the aperture. The diameter detection module samples the image of the junction 60 between the polycrystalline melt 40 and the crystal 50 , that is, samples the image of the aperture.

As shown in FIG. 2 , the single crystal diameter control device 10 includes a guide rail 102 arranged above the crucible, and the diameter detection module 101 is arranged on the guide rail 102 and can move along the guide rail 102 .

In some embodiments, the diameter detection module includes: The camera unit is used to sample the image at the junction of the polycrystalline melt and the crystal to obtain an original image; The calculation unit is used to perform binarization processing on the original image to obtain a black and white image, and calculate the area ratio L between the white area and the black area in the black and white image, L=S1/S2, wherein S1 is the area of the white area , S2 is the area of the black area; The correction unit is used to correct the area ratio by using a correction coefficient to obtain the diameter data value.

In this embodiment, the diameter detection module 101 is fixedly arranged on the guide rail 102 according to the target angle, the position of the diameter detection module 101 on the guide rail 102 can be determined according to the set target diameter of the crystal, and the diameter detection module can be adjusted according to actual needs. The position of group 101 on rail 102 . During the working process of the diameter detection module 101 , the camera unit samples the aperture, that is, the solid-liquid junction, to obtain the original image. FIG. 3 is a schematic diagram of a radial section of a crystal (including edges and crystal lines) and a detection field of view according to an embodiment of the present invention, including crystal edges 501 and protruding crystal lines 502 . As shown in Figure 4, wherein, the original image 1031 is the original image obtained in the detection field of view 103 of the diameter detection module 101, and the original image 1031 is subjected to binarization processing, that is, a gray scale threshold is set, and the original image The grayscale value of each graphic element like 1031 is compared with the grayscale threshold, if the grayscale value of the graphic element is greater than or equal to the grayscale threshold, the graphic element is adjusted to a white graphic element, if the grayscale value of the graphic element If the grayscale value is less than the grayscale threshold, adjust the primitive to be a black primitive; or, if the grayscale value of the primitive is greater than the grayscale threshold, then adjust the primitive to be a white primitive. If the grayscale value is less than or equal to the grayscale threshold, the graphic element is adjusted to a black graphic element, thereby obtaining a black and white image 1032 . Combined with the difference between the black and white pixel points, the boundary of the black and white area is fitted. It can be seen that the black and white image in the detection field of view is composed of black and white parts. Calculate the area ratio L of the white area and the black area, L=S1/S2, Among them, S1 is the area of the white area, S2 is the area of the black area, S1 represents the part occupied by the crystal in the detection field of view, S2 represents the part outside the crystal in the detection field of view, and the diameter of the crystal can be reflected by L. In this embodiment, the black-and-white image is obtained by binarizing the original image, which can realize the data noise reduction function and avoid the interference of the crystal line on the crystal surface to the detection result.

In some embodiments, in order to reduce the amount of data processing, the background in the original image may be removed before performing binarization processing on the original image.

When the diameter detection module 101 is fixed at the set position of the guide rail 102 at a set angle, it is considered that at this position, the liquid level point detected by the diameter detection module 101 corresponds to the target diameter. Referring to the position shown in Figure 1, the detected The area ratio of the white area to the black area in the field of view is the standard value, which is denoted as L1. When the crystal diameter is too large, the white area in the detection field of view will increase. At this time, L>L1, otherwise, L<L1. Since the reduction of the melt volume and the change of the crucible position will cause interference to the detection results in the ambient light in the thermal field, the correction coefficient can be introduced to correct the area ratio to obtain the diameter data value. For example, the coefficient α can be introduced to amplify L, and the diameter data value D=α × L can be obtained (D is not the actual diameter, but only represents or feeds back the change trend of the diameter), and the change of D value can feed back the change of the diameter of the crystal. In this embodiment , through the coefficient correction, the interference of the detection result due to the decrease of the melt volume and the change of the crucible position caused by the ambient light change in the thermal field can be minimized.

After the diameter data value is obtained, the crystal formation process can be controlled according to the diameter data value. In some embodiments, the control module is specifically used to increase the crystal pulling speed of the seed crystal pulling structure and/or the power of the heater when the diameter data value is greater than the preset diameter data value; When the data value is less than the predetermined diameter data value, reduce the crystal pulling speed of the seed crystal pulling structure and/or the power of the heater.

When the diameter data value is greater than the preset diameter data value, it means that the actual diameter of the crystal is greater than the target diameter, and the crystal pulling speed of the seed crystal pulling structure and/or the power of the heater can be increased to ensure that the actual diameter is consistent with the target The diameters are similar or equal; when the diameter data value is less than the preset diameter data value, it means that the actual diameter of the crystal is smaller than the target diameter, and the crystal pulling speed of the seed crystal pulling structure and/or the power of the heater can be reduced, Ensure that the actual diameter is close to or equal to the target diameter.

The embodiment of the present invention also provides a single crystal silicon crystal pulling furnace, which includes a furnace body, a crucible, a heater, and a seed crystal pulling structure located above the crucible. The liquid also includes the single crystal diameter control device as described above.

The embodiment of the present invention also provides a single crystal diameter control method, which is applied to a single crystal silicon crystal pulling furnace. The single crystal silicon crystal pulling furnace includes a furnace body, a crucible and a heater are arranged in the furnace body, and a Seed crystal pulling structure, the crucible is used to contain polycrystalline melt, as shown in Figure 5, the single crystal diameter control method includes: Step S01: Sampling the image at the junction of the polycrystalline melt and the crystal to obtain an original image, performing binarization on the original image to obtain a black and white image, and calculating the difference between the white area and the black area in the black and white image. The area ratio of the region, according to which the diameter data value of the crystal is obtained; Step S02: Compare the diameter data value with a preset diameter data value, and control the crystal pulling speed of the seed crystal pulling structure and/or the power of the heater according to the comparison result.

In this embodiment, by monitoring the junction of the polycrystalline melt and the crystal, the diameter of the crystal during crystal formation can be monitored, and the crystal pulling speed and/or heater power of the seed crystal pulling structure can be adjusted in real time, The diameter of the crystal can reach the target diameter. This embodiment can ensure the authenticity of the crystal diameter obtained during the crystal growth process, ensure the stability of the crystal pulling speed, and improve the stability and controllability of the crystal quality.

During the crystal pulling process, polysilicon is put into the crucible 30 and heated and melted to become a polycrystalline melt 40, and a crystal with a specific crystal orientation is fixed at the lower end of the seed chuck structure. When pulling a single crystal silicon rod, first The crystal is welded with the polycrystalline melt, starting to enter the seeding stage; then by adjusting the temperature of the polycrystalline molten liquid, the upward lifting speed of the crystal, etc., the monocrystalline silicon continues to grow through the shoulder laying stage and the shoulder turning stage, and finally drawn out of monocrystalline silicon rods. Among them, the guide tube 20 is used to separate the temperature at the liquid surface from the surrounding environment of the ingot, so as to ensure a suitable crystal growth temperature gradient; the crucible 30 can be made of materials such as quartz or dock, and the inner wall is relatively smooth, with certain light reflection Function: the crystal edge 501 (including the protruding crystal lines) of the grown crystal 50 is welded to the polycrystalline melt 40 .

During the crystal growth process, at the junction 60 of the crystal 50 and the polycrystalline melt 40, the solid-liquid surface forms a meniscus structure due to the surface tension of the melt. The lunar surface structure will emit light with a brightness higher than that of the surrounding area, which is called the aperture. The diameter detection module samples the image of the junction 60 between the polycrystalline melt 40 and the crystal 50 , that is, samples the image of the aperture.

As shown in FIG. 2 , the single crystal diameter control device 10 includes a guide rail 102 arranged above the crucible, and the diameter detection module 101 is arranged on the guide rail 102 and can move along the guide rail 102 .

In this embodiment, the diameter detection module 101 is fixedly arranged on the guide rail 102 according to the target angle, the position of the diameter detection module 101 on the guide rail 102 can be determined according to the set target diameter of the crystal, and the diameter detection module can be adjusted according to actual needs. The position of group 101 on rail 102 . During the working process of the diameter detection module 101 , the camera unit samples the aperture, that is, the solid-liquid junction, to obtain the original image. FIG. 3 is a schematic diagram of a radial section of a crystal (including edges and crystal lines) and a detection field of view according to an embodiment of the present invention, which includes a crystal edge 501 and a protruding crystal line 502 . As shown in Figure 4, wherein, the original image 1031 is the original image obtained in the detection field of view 103 of the diameter detection module 101, and the original image 1031 is subjected to binarization processing, that is, a gray scale threshold is set, and the original image The grayscale value of each graphic element like 1031 is compared with the grayscale threshold, if the grayscale value of the graphic element is greater than or equal to the grayscale threshold, the graphic element is adjusted to a white graphic element, if the grayscale value of the graphic element If the grayscale value is less than the grayscale threshold, adjust the primitive to be a black primitive; or, if the grayscale value of the primitive is greater than the grayscale threshold, then adjust the primitive to be a white primitive. If the grayscale value is less than or equal to the grayscale threshold, the graphic element is adjusted to a black graphic element, thereby obtaining a black and white image 1032 . Combined with the difference between the black and white pixel points, the boundary of the black and white area is fitted. It can be seen that the black and white image in the detection field of view is composed of black and white parts. Calculate the area ratio L of the white area and the black area, L=S1/S2, Among them, S1 is the area of the white area, S2 is the area of the black area, S1 represents the part occupied by the crystal in the detection field of view, S2 represents the part outside the crystal in the detection field of view, and the diameter of the crystal can be reflected by L. In this embodiment, the black-and-white image is obtained by binarizing the original image, which can realize the data noise reduction function and avoid the interference of the crystal line on the crystal surface to the detection result.

In some embodiments, in order to reduce the amount of data processing, the background in the original image may be removed before performing binarization processing on the original image.

When the diameter detection module 101 is fixed at the set position of the guide rail 102 at a set angle, it is considered that at this position, the liquid level point detected by the diameter detection module 101 corresponds to the target diameter. Referring to the position shown in Figure 1, the detected The area ratio of the white area to the black area in the field of view is the standard value, which is denoted as L1. When the crystal diameter is too large, the white area in the detection field of view will increase. At this time, L>L1, otherwise, L<L1. Since the reduction of the melt volume and the change of the crucible position will cause interference to the detection results in the ambient light in the thermal field, the correction coefficient can be introduced to correct the area ratio to obtain the diameter data value. For example, the coefficient α can be introduced to amplify L, and the diameter data value D=α × L can be obtained (D is not the actual diameter, but only represents or feeds back the change trend of the diameter), and the change of D value can feed back the change of the diameter of the crystal. In this embodiment , through the coefficient correction, the interference of the detection result due to the decrease of the melt volume and the change of the crucible position caused by the ambient light change in the thermal field can be minimized.

After the diameter data value is obtained, the crystal formation process can be controlled according to the diameter data value. In some embodiments, the method specifically includes: When the diameter data value is greater than the preset diameter data value, increase the crystal pulling speed of the seed crystal pulling structure and/or the power of the heater; when the diameter data value is smaller than the preset diameter data value, decrease The crystal pulling speed of the seed crystal pulling structure and/or the power of the heater.

When the diameter data value is greater than the preset diameter data value, it means that the actual diameter of the crystal is greater than the target diameter, and the crystal pulling speed of the seed crystal pulling structure and/or the power of the heater can be increased to ensure that the actual diameter is consistent with the target The diameters are similar or equal; when the diameter data value is less than the preset diameter data value, it means that the actual diameter of the crystal is smaller than the target diameter, and the crystal pulling speed of the seed crystal pulling structure and/or the power of the heater can be reduced, Ensure that the actual diameter is close to or equal to the target diameter.

An embodiment of the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for controlling the diameter of a single crystal as described above are implemented.

The above are only preferred embodiments of the present invention, and are not used to limit the implementation scope of the present invention. If the present invention is modified or equivalently replaced without departing from the spirit and scope of the present invention, it shall be covered by the protection of the patent scope of the present invention. in the range.

10: Single crystal diameter control device 20: deflector 30: Crucible 40: polycrystalline melt 50:Crystal 60: Junction 101: Diameter detection module 102: guide rail 103: Detection Field of View 501: crystal edge 502: protruding crystal line 1031: Original image 1032: black and white image S01-S02: Steps

Fig. 1 is the schematic diagram of the crystal growth of the embodiment of the present invention; 2 is a schematic structural view of a single crystal diameter control device according to an embodiment of the present invention; Fig. 3 is a schematic diagram of a radial cross-section (including edges and crystal lines) and a detection field of view of a crystal according to an embodiment of the present invention; Fig. 4 is a schematic diagram of processing images in the detection field of view according to an embodiment of the present invention; Fig. 5 is a schematic flowchart of a single crystal diameter control method according to an embodiment of the present invention.

S01-S02: Steps

Claims (9)

A single crystal diameter control device, applied to a single crystal silicon crystal pulling furnace, the single crystal silicon crystal pulling furnace includes a furnace body, the furnace body is provided with a crucible and a heater, and a seed crystal pulling structure located above the crucible, the crucible Used to contain polycrystalline melt, the single crystal diameter control device includes: The diameter detection module is used to sample the image at the junction of the polycrystalline melt and the crystal to obtain the original image, perform binarization on the original image to obtain a black and white image, and calculate the black and white image The area ratio of the white area to the black area, according to the area ratio, the diameter data value of the crystal is obtained; The control module is used to compare the diameter data value with a preset diameter data value, and control the crystal pulling speed of the seed crystal pulling structure and/or the power of the heater according to the comparison result. The single crystal diameter control device according to claim 1, wherein, The control module is specifically used to increase the crystal pulling speed of the seed crystal pulling structure and/or the power of the heater when the diameter data value is greater than the preset diameter data value; When setting the diameter data value, reduce the crystal pulling speed of the seed crystal pulling structure and/or the power of the heater. The single crystal diameter control device as described in Claim 1, further comprising: a guide rail disposed above the crucible; The diameter detecting module is arranged on the guide rail and can move along the guide rail. The single crystal diameter control device as described in Claim 1, wherein the diameter detection module includes: The camera unit is used to sample the image at the junction of the polycrystalline melt and the crystal to obtain an original image; The calculation unit is used to perform binarization processing on the original image to obtain a black and white image, and calculate the area ratio L between the white area and the black area in the black and white image, L=S1/S2, wherein S1 is the area of the white area , S2 is the area of the black area; The correction unit is used to correct the area ratio by using a correction coefficient to obtain the diameter data value. A single crystal silicon crystal pulling furnace, comprising a furnace body, the furnace body is provided with a crucible and a heater, and a seed crystal pulling structure located above the crucible, the crucible is used to contain polycrystalline melt, and also includes request item 1 The single crystal diameter control device described in any one of to 4. A single crystal diameter control method, applied to a single crystal silicon crystal pulling furnace, the single crystal silicon crystal pulling furnace includes a furnace body, the furnace body is provided with a crucible and a heater, and a seed crystal pulling structure located above the crucible, the crucible Used to contain polycrystalline melt, the single crystal diameter control method includes: Sampling the image at the junction of the polycrystalline melt and the crystal to obtain the original image, performing binarization on the original image to obtain a black and white image, and calculating the area of the white area and the black area in the black and white image Ratio, the diameter data value of the crystal is obtained according to the area ratio; Comparing the diameter data value with a preset diameter data value, and controlling the crystal pulling speed of the seed crystal pulling structure and/or the power of the heater according to the comparison result. The single crystal diameter control method as described in Claim 6, the method specifically includes: When the diameter data value is greater than the preset diameter data value, increase the crystal pulling speed of the seed crystal pulling structure and/or the power of the heater; when the diameter data value is smaller than the preset diameter data value, decrease The crystal pulling speed of the seed crystal pulling structure and/or the power of the heater. The method for controlling the diameter of a single crystal as described in Claim 6, wherein the data value of the diameter of the crystal obtained according to the area ratio includes: The area ratio is corrected by the correction coefficient to obtain the diameter data value. A computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for controlling the diameter of a single crystal as described in any one of claims 6 to 8 are realized.

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