A single crystal silicon growth system and growth control method

Abstract

An embodiment of the present invention provides a single crystal silicon growth system and a growth control method. In the single crystal silicon growth system, a single crystal silicon growth device includes a crucible, a guide tube and a bracket, wherein the bracket is used to support the guide tube to be suspended in the crucible; the crucible is used to carry molten single crystal silicon, the molten single crystal silicon spontaneously generates radiant light, and the radiant light is transmitted to the bottom of the guide tube; the guide tube also includes a first hole and at least one second hole, and the first hole and the second hole pass through the bottom; wherein the opening area of ​​the first hole is larger than the opening area of ​​the second hole; the radiant light is reflected to the liquid surface of the molten single crystal silicon at the reflection structure, and the radiant light is emitted at the second hole; the image acquisition unit obtains the liquid surface image of the molten single crystal silicon through the first hole; the control unit is connected to the image acquisition unit, and the control unit determines the distance between the liquid surface of the molten single crystal silicon and the guide tube according to the liquid surface image. The technical solution provided by this embodiment is adopted to simplify the single crystal silicon growth system while ensuring accurate judgment of the liquid inlet.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of single crystal silicon preparation, and in particular to a single crystal silicon growth system and a growth control method. Background Art

[0002] High-purity single-crystal silicon is an important semiconductor material that can be made into diodes, triodes, thyristors and various integrated circuits (including the chips and CPUs in people's computers). It can also be made into solar photovoltaic cells to convert radiation energy into electrical energy.

[0003] The growth conditions of high-purity single crystal silicon are multifaceted, including temperature, pressure, atmosphere, purity of silicon raw materials and growth methods. These factors interact with each other and jointly determine the growth rate and quality of single crystal silicon. In order to meet the needs of high-performance semiconductor devices, we need high-quality single crystal silicon rods with low defects. An important parameter affecting the defect properties of single crystal silicon is the liquid mouth distance, that is, the distance from the guide tube to the liquid surface of the silicon melt. This parameter may change with changes in other conditions during the growth of single crystal silicon, thereby affecting the growth and quality of single crystal silicon. Therefore, real-time measurement of the liquid mouth distance is of great significance to the defect control of single crystal silicon. Summary of the invention

[0004] An embodiment of the present invention provides a single crystal silicon growth system and a growth control method. An image acquisition unit obtains a liquid surface image of molten single crystal silicon through a first hole. A control unit determines the distance between the liquid surface of the molten single crystal silicon and a guide tube according to the liquid surface image. This simplifies the single crystal silicon growth system while ensuring accurate judgment of the liquid inlet.

[0005] In a first aspect, an embodiment of the present invention provides a single crystal silicon growth system, including a single crystal silicon growth device, an image acquisition unit and a control unit;

[0006] The single crystal silicon growth device comprises a crucible, a guide tube and a bracket, wherein the bracket is mechanically connected to the crucible and the guide tube respectively, and the bracket is used to support the guide tube to be suspended in the crucible; the crucible is used to carry molten single crystal silicon, the molten single crystal silicon spontaneously generates radiation light, and the radiation light is transmitted to the bottom of the guide tube; the bottom comprises a reflective structure on a side close to the crucible, and the guide tube further comprises a first hole and at least one second hole, and the first hole and the second hole penetrate the bottom; wherein the opening area of ​​the first hole is larger than the opening area of ​​the second hole;

[0007] Reflecting the radiation light to the liquid surface of the molten single crystal silicon at the reflection structure, and emitting the radiation light at the second hole;

[0008] The image acquisition unit acquires a liquid surface image of the molten single crystal silicon through the first hole;

[0009] The control unit is connected to the image acquisition unit, and the control unit determines the distance between the liquid level of the molten silicon single crystal and the guide tube according to the liquid level image.

[0010] Optionally, the first hole includes a first opening and a second opening, the first opening is located on a side of the bottom away from the crucible, the second opening is located on a side of the bottom close to the crucible, and a projection of the first opening onto the crucible is located away from a projection of the second opening onto the crucible and away from a projection of the second hole onto the crucible.

[0011] Optionally, the first hole includes a first side edge, and the first opening and the second opening are connected via the first side edge; the first side edge extends along a first direction;

[0012] A line connecting the center of the image acquisition unit and the first hole extends along the first direction.

[0013] Optionally, along the second direction, the length of the first hole is L1, and the length of the second hole is L2;

[0014] Wherein, L1≥2L2, L1 and L2 are positive numbers, and the second direction is the direction from the first hole to the second hole.

[0015] Optionally, along the third direction, the width of the first hole is W1, and the width of the second hole is W2;

[0016] Wherein, W1≥W2, W1 and W2 are positive numbers, and the third direction is perpendicular to the direction from the first hole to the second hole.

[0017] Optionally, the material of the bottom of the guide tube includes reflective material.

[0018] Optionally, the image acquisition unit includes a digital camera.

[0019] Optionally, the control unit is connected to the bracket, and is used to adjust the position of the crucible through the bracket.

[0020] In a second aspect, an embodiment of the present invention provides a growth control method for single crystal silicon, which is applied to the single crystal silicon growth system described in any one of the first aspects, wherein the single crystal silicon growth system comprises: a single crystal silicon growth device, an image acquisition unit and a control unit; the single crystal silicon growth device comprises a crucible, a guide tube and a bracket, wherein the bracket is mechanically connected to the crucible and the guide tube respectively, and the bracket is used to support the guide tube to be suspended in the crucible; the crucible is used to carry molten single crystal silicon, and the molten single crystal silicon spontaneously generates radiant light; the bottom of the guide tube includes a reflective structure on one side close to the crucible, and the guide tube also includes a first hole and at least one second hole, and the first hole and the second hole pass through the bottom; wherein the opening area of ​​the first hole is larger than the opening area of ​​the second hole; the control method comprises:

[0021] Controlling the image acquisition unit to acquire the liquid surface image of the molten silicon monocrystalline; transmitting the radiation light to the bottom, reflecting the radiation light to the liquid surface of the molten silicon monocrystalline at the reflection structure, and emitting the radiation light at the second hole;

[0022] The distance between the liquid surface of the molten silicon single crystal and the guide tube is determined according to the liquid surface image.

[0023] Optionally, judging the distance between the liquid surface of the molten silicon single crystal and the guide tube according to the liquid surface image further includes:

[0024] According to the distance, the position of the crucible is adjusted.

[0025] An embodiment of the present invention provides a single crystal silicon growth system, in which a single crystal silicon growth device includes a crucible, a guide tube and a bracket, the bracket is mechanically connected to the crucible, and the bracket is mechanically connected to the guide tube, that is, the bracket is used to fix and adjust the setting position of the crucible and the guide tube. Specifically, the bracket is used to support the guide tube to be suspended in the crucible, and the bottom of the guide tube is adjusted to be located in the crucible. The crucible is used to carry molten single crystal silicon. The molten single crystal silicon will generate radiation light due to its own properties, and the radiation light will be transmitted to the bottom of the guide tube and illuminate the bottom of the guide tube; The bottom of the guide tube of the first step includes a first hole and a second hole, wherein the radiation light is reflected to the liquid surface of the molten single crystal silicon at the reflection structure, but the radiation light is emitted at the second hole, that is, the light at the second hole will no longer be reflected to the liquid surface of the molten single crystal silicon; the image acquisition unit obtains the liquid surface image of the molten single crystal silicon through the first hole and transmits the liquid surface image to the control unit, and the control unit judges the distance between the liquid surface of the molten single crystal silicon and the guide tube according to the liquid surface image, that is, the control unit judges the liquid mouth distance according to the position of the second hole in the liquid surface image that does not reflect the light. The technical solution provided by this embodiment simplifies the single crystal silicon growth system while ensuring accurate judgment of the liquid mouth, which is beneficial to improving the defect control of single crystal silicon in combination with accurate liquid mouth distance.

[0026] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required to describe the embodiments. Obviously, the drawings introduced are only drawings of a part of the embodiments to be described in the present invention, rather than all the drawings. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 is a structural schematic diagram of a first single crystal silicon growth system provided by an embodiment of the present invention;

[0029] Figure 2 yes Figure 1 A liquid surface image of a single crystal silicon growth system provided in;

[0030] Figure 3 is a structural schematic diagram of a second single crystal silicon growth system provided by an embodiment of the present invention;

[0031] Figure 4 yes Figure 3 A liquid surface image of a single crystal silicon growth system provided in;

[0032] Figure 5 is a bottom top view schematic diagram of a guide tube provided by an embodiment of the present invention;

[0033] Figure 6 is a schematic structural diagram of a third single crystal silicon growth system provided by an embodiment of the present invention;

[0034] Figure 7 is a schematic structural diagram of a fourth single crystal silicon growth system provided by an embodiment of the present invention;

[0035] Figure 8 is a structural schematic diagram of a fifth single crystal silicon growth system provided by an embodiment of the present invention;

[0036] Fig. 9 is an enlarged schematic diagram of the bottom of a guide tube provided by an embodiment of the present invention;

[0037] Fig.10 is a flow chart of a method for controlling growth of single crystal silicon provided by an embodiment of the present invention;

[0038] Fig.11 It is a flow chart of another method for controlling the growth of single crystal silicon provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0039] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0040] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a system, product or device comprising a series of units is not necessarily limited to those steps or units clearly listed, but may include other units that are not clearly listed or inherent to these products or devices.

[0041] Figure 1 is a schematic structural diagram of a first single crystal silicon growth system provided by an embodiment of the present invention, Figure 2 yes Figure 1 A liquid surface image of a single crystal silicon growth system provided in Figure 3 is a schematic structural diagram of a second single crystal silicon growth system provided in an embodiment of the present invention, Figure 4 yes Figure 3 A liquid surface image of a single crystal silicon growth system provided in Figure 5 is a bottom top view of a guide tube provided by an embodiment of the present invention, with reference to Figures 1 to 5As shown, an embodiment of the present invention provides a single crystal silicon growth system 10, which includes a single crystal silicon growth device 100, an image acquisition unit 200 and a control unit 300; the single crystal silicon growth device 100 includes a crucible 110, a guide tube 120 and a bracket (not specifically shown in the figure), the bracket is mechanically connected to the crucible 110 and the guide tube 120 respectively, and the bracket is used to support the guide tube 120 to be suspended in the crucible 110; the crucible 110 is used to carry molten single crystal silicon 20, the molten single crystal silicon 20 spontaneously generates radiation light, and the radiation light is transmitted to the bottom 120a of the guide tube 120; the bottom 120a close to the crucible 110 includes a reflective structure on one side 122, the guide tube 120 also includes a first hole 121a and at least one second hole 121b, the first hole 121a and the second hole 121b pass through the bottom 120a; wherein, the opening area of ​​the first hole 121a is larger than the opening area of ​​the second hole 121b; the radiation light is reflected to the liquid surface of the molten single crystal silicon 20 at the reflection structure 122, and the radiation light is emitted at the second hole 121b; the image acquisition unit 200 obtains the liquid surface image of the molten single crystal silicon 20 through the first hole 121a; the control unit 300 is connected to the image acquisition unit 200, and the control unit 300 determines the distance between the liquid surface of the molten single crystal silicon 20 and the guide tube 120 according to the liquid surface image.

[0042] Among them, the single crystal silicon growth system 10 includes a single crystal silicon growth device 100, which is used to carry silicon raw materials and prepare single crystal silicon by adjusting factors such as temperature and pressure. Specifically, the single crystal silicon growth device 100 includes a crucible 110 and a guide tube 120. The crucible 110 can be used to carry molten single crystal silicon 20, and its stable liquid surface can form a reflecting surface. And the surface temperature of the molten single crystal silicon is generally above 1400°C, and radiant light will be spontaneously generated. The specific temperature of the molten single crystal silicon 20 in the crucible 110 is not specifically limited in the embodiment of the present invention. The guide tube 120 can be understood as a heat shield. The presence of the guide tube 120 can guide inert gas such as argon to flow in a directional manner, ensuring that the molten single crystal silicon 20 in the crucible 110 is always filled with argon, so that the single crystal silicon 20 grows under the protection of the surrounding atmosphere.

[0043] Furthermore, the single crystal silicon growth device 100 further includes a bracket (not specifically shown in the figure), which is mechanically connected to the crucible 110 and the guide tube 120, that is, the bracket can support the crucible 110 and the guide tube 120, and the bracket can also adjust the positions of the crucible 110 and the guide tube 120. Specifically, the bracket is used to support the guide tube 120 to be suspended in the crucible 110. It should be noted that Figure 1 and Figure 3The bracket is not specifically shown in the figure. For different single crystal silicon growth systems 10, the setting shape and position of the bracket can be adaptively adjusted. The setting of the bracket is used to ensure that the positions of the crucible 110 and the guide tube 120 are fixed and adjusted. The embodiment of the present invention does not provide a specific description of this.

[0044] Furthermore, the radiation light of the molten silicon monocrystalline 20 will illuminate the side of the guide tube 120 close to the crucible 110, that is, the radiation light will illuminate the bottom 120a of the guide tube 120. The side of the bottom 120a close to the crucible 110 includes a reflective structure 122, and the reflective structure 122 will reflect the illuminated bottom 120a to the liquid surface of the molten silicon monocrystalline 20, that is, a reflection of the bottom 120a will be formed on the liquid surface.

[0045] Optional, Figure 6 is a schematic diagram of the structure of a third single crystal silicon growth system provided by an embodiment of the present invention, with reference to Figure 1 , Figure 3 and Figure 6 As shown, the material of the bottom 120 a of the guide tube 120 includes a reflective material.

[0046] The radiation light transmitted to the bottom 120a will be transmitted to the liquid surface of the molten silicon monocrystalline 20 by reflection. The bottom 120a should have a reflective property to ensure the reflection effect of the radiation light. Specifically, when the material of the guide tube 120 has a reflective property, the reflective structure 122 of the bottom 120a can be the main body structure of the guide tube 120, such as Figure 1 and Figure 3 As shown, there is no need to add an additional film layer structure for achieving reflection. Figure 6 As shown, a reflective layer can be added to the bottom 120a of the guide tube 120, and the reflective layer can achieve the effect of reflecting light. The reflective layer is the reflective structure 122, which is used to ensure that the radiated light is transmitted to the liquid surface of the molten single crystal silicon 20 through the reflective layer.

[0047] Among them, reference Figure 1 and Figure 3 As shown, the bottom 120a of the guide tube 120 includes a first hole 121a and a second hole 121b, and the first hole 121a and the second hole 121b penetrate the bottom 120a. The radiated light can continue to be transmitted through the first hole 121a and the second hole 121b. Where the first hole 121a and the second hole 121b are not set, there is a reflective structure 122. The radiated light transmitted to the reflective structure 122 will be reflected to the liquid surface of the molten single crystal silicon 20.

[0048] Furthermore, the single crystal silicon growth system 10 further includes an image acquisition unit 200, which is used to shoot and acquire images. Optionally, the image acquisition unit 200 includes a digital camera. The image acquisition unit 200 is located on the side of the bottom 120a away from the molten single crystal silicon 20, and the image acquisition unit 200 can acquire images of the molten single crystal silicon 20 through the first hole 121a, that is, the image acquisition unit 200 is used to acquire image information of the molten single crystal silicon 20. Figure 2 and Figure 4 As shown, the shape of the liquid surface image depends on the shape of the first hole 121a. The specific shape of the first hole 121a can be adaptively adjusted according to actual conditions, and the embodiment of the present invention does not specifically limit this. Among them, the radiation light of the molten single crystal silicon 20 will illuminate the side of the guide tube 120 close to the crucible 110, and the reflective structure 122 of the bottom 120a will reflect the illuminated bottom 120a to the liquid surface of the molten single crystal silicon 20, that is, a reflection of the bottom 120a will be formed on the liquid surface. In fact, the image acquisition unit 200 acquires the image of the reflection of the liquid surface of the molten single crystal silicon 20 through the first hole 121a.

[0049] Specifically, the radiation light transmitted to the bottom 120a will be reflected at the reflective structure 122 and then transmitted to the liquid surface of the molten single crystal silicon 20. The image acquisition unit 200 set at the first hole 121a can capture the image of the liquid surface of the molten single crystal silicon 20 through the first hole 121a, that is, the liquid surface image, and capture the image of the reflection of the bottom 120a fed back at the liquid surface. At the second hole 121b, the radiation light provided by the molten single crystal silicon 20 is directly emitted, so the radiation light transmitted to the second hole 121b will not be reflected to the liquid surface of the molten single crystal silicon 20. Therefore, in the reflection image of the bottom 120a fed back at the liquid surface of the molten single crystal silicon 20, the corresponding area of ​​the second hole 121b is a dark area, which can be as follows: Figure 2 and Figure 4 The black spot 121b1 is shown.

[0050] Furthermore, the opening area of ​​the first hole 121a is larger than the opening area of ​​the second hole 121b. Figures 1 to 4 As shown, the black spot 121b1 formed by the second hole 121b without reflection will be fed back through the image information collected by the first hole 121a. In order to ensure the clear acquisition of the position of the black spot 121b1, the opening area of ​​the first hole 121a is adjusted to be larger than the opening area of ​​the second hole 121b. Figure 5 As shown, Figure 5 is a schematic top view of the bottom 120a of the guide tube 120. The first hole 121a and the second hole 121b both penetrate the bottom 120a. Figure 5The dotted lines marked in the figure can be understood as the surface openings of the first hole 121a and the second hole 121b in the bottom 120a close to the side of the crucible 110. Optionally, the distance between the first hole 121a and the second hole 121b can be adaptively adjusted. In the actual production process, the distance between the first hole 121a and the second hole 121b can be specifically adjusted for different processes for setting the liquid port distance.

[0051] Optional, Figure 7 is a schematic structural diagram of a fourth single crystal silicon growth system provided in an embodiment of the present invention, Figure 8 is a schematic diagram of the structure of the fifth single crystal silicon growth system provided in an embodiment of the present invention, with reference to Figure 6 and Figure 8 As shown, the single crystal silicon growth system 10 includes an image acquisition unit 200, and thus the single crystal silicon growth system 10 includes a first hole 121a corresponding to the image acquisition unit 200. As for the second hole 121b in the single crystal silicon growth system 10, the second hole 121b is used to block the reflection of the radiation light transmitted to the second hole 121b, and then exists in the form of a black spot in the image information collected by the image acquisition unit 200, so as to be used to feedback the distance between the molten single crystal silicon 20 and the bottom 120a. Therefore, the second hole 121b can be understood as a positioning function, and the number of the second holes 121b can be adaptively adjusted according to the overall size of the bottom 120a and the size of the first hole 121a. If the sizes of the bottom 120a and the first hole 121a are both relatively large, a plurality of second holes 121b can be set, such as Figure 8 As shown, the liquid mouth distance can be more accurately judged according to the black spots of different second holes 121b, and the sizes and shapes of different second holes 121b can also be adaptively adjusted; if the sizes of the bottom 120a and the first hole 121a are relatively small, only one second hole 121b can be provided, such as Figures 1 to 7 shown.

[0052] Specifically, when the liquid level of the molten silicon single crystal 20 in the crucible 110 is Figure 1 When the liquid outlet distance is La, the image information collected by the image acquisition unit 200 is as follows: Figure 2 As shown; when the liquid level of the molten single crystal silicon 20 in the crucible 110 is at Figure 3 When the position is shown, the liquid port distance is Lb, and the image information collected by the image acquisition unit 200 is as follows Figure 4 As shown. Combined Figure 2 and Figure 4As shown, when the liquid level of the molten silicon monocrystalline 20 changes with the bottom 120a, the position of the black spot 121b1 in the corresponding collected image will change. Further, the image acquisition unit 200 is connected to the control unit 300, and the control unit 300 can judge the liquid level height of the molten silicon monocrystalline 20 based on the liquid level image collected by the image acquisition unit 200. Further, compared with the first hole 121a and the second hole 121b, the second hole 121b can be understood as a short hole, and the first hole 121a can be understood as a long hole. In the single crystal silicon growth system 10, in the image information obtained by the image acquisition unit 200 through the first hole 121a (long hole), the second hole 121b (short hole) exists in the image information in the form of a black spot corresponding to the short hole. Combining the long hole and the short hole, it is ensured that the image information obtained in the single crystal silicon growth system 10 is more recognizable, which is convenient for judging the liquid mouth distance. At the same time, the setting of the first hole 121a and the second hole 121b at the bottom 120a of the guide tube 120, that is, a simple punching design is performed on the bottom 120a of the guide tube 120, has very little impact on the functional structure of the heat shield of the guide tube 120, and has a smaller risk of powder contamination during the preparation process, thereby less interference with the airflow and less impact on the process conditions.

[0053] Among them, the single crystal silicon growth system 10 provided in the embodiment of the present invention has different setting requirements for the liquid nozzle distance under different growth environments or different process requirements. Using the single crystal silicon growth system 10 provided in the embodiment of the present invention, while ensuring that the liquid nozzle distance is set within the expected range, there is no need to replace the hardware or switch the process, and only needs to adjust the target position of the black spot in the control unit 300 (for example, on the human-computer interaction interface).

[0054] Among them, for the crystalline silicon growth system 10, by changing the size of the first hole 121a and the distance between the second hole 121b, the liquid inlet distance range can be adjusted to meet the needs of more process conditions and actual production environments. In other words, according to the actual liquid inlet distance range requirements, the distance between the first hole 121a and the second hole 121b can be correspondingly adjusted to ensure that the crystalline silicon growth system 10 detects the liquid inlet distance.

[0055] Optionally, the control unit 300 and the image acquisition unit 200 may be electrically connected or communicatively connected. The specific connection mode is not specifically shown in the embodiment of the present invention.

[0056] In summary, an embodiment of the present invention provides a single crystal silicon growth system, wherein a crucible is used to carry molten single crystal silicon. The molten single crystal silicon will generate radiation light due to its own properties. The radiation light will be transmitted to the bottom of the guide tube and illuminate the bottom of the guide tube; further, the bottom of the guide tube includes a first hole and a second hole, wherein the radiation light is reflected to the liquid surface of the molten single crystal silicon at the reflection structure, but the light at the second hole will no longer be reflected to the liquid surface of the molten single crystal silicon; the image acquisition unit obtains the liquid surface image of the molten single crystal silicon through the first hole and transmits the liquid surface image to the control unit, and the control unit determines the distance between the liquid surface of the molten single crystal silicon and the guide tube according to the liquid surface image, that is, the control unit determines the liquid mouth distance according to the position of the second hole in the liquid surface image that does not reflect the light. The technical solution provided by this embodiment simplifies the single crystal silicon growth system while ensuring accurate judgment of the liquid mouth, which is beneficial to improving the defect control of single crystal silicon in combination with accurate liquid mouth distance.

[0057] Fig. 9 is an enlarged schematic diagram of the bottom of a guide tube provided by an embodiment of the present invention, with reference to Figures 1 to 9 As shown, the first hole 121a includes a first opening 121a1 and a second opening 121a2, the first opening 121a1 is located on the side of the bottom 120a away from the crucible 110, the second opening 121a2 is located on the side of the bottom 120a close to the crucible 110, and the projection of the first opening 121a1 to the crucible 110 is located away from the projection of the second opening 121a2 to the crucible 110 away from the projection of the second hole 121b to the crucible 110.

[0058] Specifically, refer to Fig. 9 As shown, the first hole 121a penetrating the bottom 120a includes a first opening 121a1 and a second opening 121a2, wherein the first opening 121a1 is located on the side of the bottom 120a away from the crucible 110, and the second opening 121a2 is located on the side of the bottom 120a close to the crucible 110. The first opening 121a1 and the second opening 121a2 are staggered, that is, the projection of the first opening 121a1 to the crucible 110 is located at the projection of the second opening 121a2 to the crucible 110 away from the projection of the second hole 121b to the crucible 110, which reflects that the first hole 121a is an inclined aperture arranged on the bottom 120a, and the first opening 121a1 points to the direction of the second opening 121a2 close to the second hole 121b. By adjusting the inclination direction of the first hole 121a, it is possible to ensure that the light image acquisition unit 200 acquires the liquid surface image, thereby ensuring the accurate judgment of the liquid mouth distance, which is beneficial to improving the defect control of the single crystal silicon.

[0059] Optionally, the second hole 121b may be Figure 7 As shown, the aperture is not inclined, or the second hole 121b can also be as shown. Figure 1 , Figure 3 and Figure 5 As shown, the aperture is also arranged obliquely, and the inclination directions of the first hole 121a and the second hole 121b intersect, reflecting that the arrangement of the second hole 121b is diverse.

[0060] Continue to refer Figures 1 to 9 As shown, the first hole 121a includes a first side 121a3, the first opening 121a1 and the second opening 121a2 are connected by the first side 121a3; the first side 121a3 extends along the first direction X1; and the line connecting the image acquisition unit 200 and the center a0 of the first hole 121a extends along the first direction X1.

[0061] For further reference, Fig. 9 As shown, the first hole 121a includes a first side 121a3, and the first opening 121a1 and the second opening 121a2 are connected by the first side 121a3. The first side 121a3 extends along the first direction X1. Since the first hole 121a is an inclined aperture set on the bottom 120a, the first direction X1 has an angle with the thickness direction of the bottom 120a and the extension direction of the bottom 120a.

[0062] For further reference, Fig. 9 As shown, the line connecting the image acquisition unit 200 and the center a0 of the first hole 121a extends along the first direction X1, that is, the setting of the image acquisition unit 200 relative to the first hole 121a is related to the inclination angle of the first hole 121a, thereby ensuring that the image acquisition unit 200 can better capture the liquid surface image through the first hole 121a, avoiding the side of the first hole 121a from interfering with the liquid surface image capture, thereby ensuring that the single crystal silicon growth system 10 has accuracy in judging the liquid mouth distance.

[0063] Continue to refer Figures 1 to 5 As shown, along the second direction X2, the length of the first hole 121a is L1, and the length of the second hole 121b is L2; ​​wherein L1≥2L2, L1 and L2 are positive numbers, and the second direction X2 is the direction from the first hole 121a to the second hole 121b.

[0064] Among them, reference Figures 1 to 5As shown, along the direction from the first hole 121a to the second hole 121b, the length of the first hole 121a is greater than the length of the second hole 121b, which is used to ensure that the black spot of the second hole 121b can be collected by the image acquisition unit 200 through the first hole 121a. Further, the length of the first hole 121a is L1, and the length of the second hole 121b is L2; ​​wherein L1≥2L2 is satisfied. In the liquid surface image collected by the image acquisition unit 200, the position of the black spot 121b1 along the second direction X2 is used to determine the size of the liquid mouth distance, so the length of the first hole 121a is limited to be greater than or equal to twice the length of the second hole 121b, thereby ensuring that the position of the black spot of the second hole 121b can be better determined in the image collected by the image acquisition unit 200, and the liquid mouth distance can be accurately inferred. If the length of the first hole 121a is similar to the length of the second hole 121b, when the liquid mouth distance changes, the position of the black spot does not change significantly, which is easy to affect the judgment of the liquid mouth distance.

[0065] Continue to refer Figures 1 to 5 As shown, along the third direction X3, the width of the first hole 121a is W1, and the width of the second hole 121b is W2; wherein W1≥W2, W1 and W2 are positive numbers, and the third direction X3 is perpendicular to the direction from the first hole 121a to the second hole 121b.

[0066] In the direction perpendicular to the first hole 121a and pointing to the second hole 121b, the width of the first hole 121a is greater than or equal to the width of the second hole 121b, that is, the width of the first hole 121a is W1, and the width of the second hole 121b is W2; wherein W1≥W2. By limiting the width of the first hole 121a and the width of the second hole 121b, the black spot of the second hole 121b can be present in the image captured by the image acquisition unit 200, and the liquid port distance can be accurately estimated.

[0067] Continue to refer Figures 1 to 9 The control unit 300 is connected to the bracket and is used to adjust the position of the crucible 110 through the bracket.

[0068] The control unit 300 determines the distance between the molten silicon single crystal 20 and the bottom 120a of the guide tube 120, i.e., the liquid inlet distance, according to the liquid surface image acquired by the image acquisition unit 200. If the determined liquid inlet distance does not meet the expected setting range, the liquid inlet distance can be further adjusted by adjusting the position of the crucible 110, and further judgment can be made in combination with the re-acquired liquid surface image, so as to ensure that the liquid inlet distance meets the required range, and the data of the liquid inlet distance can be acquired and judged in a timely manner.

[0069] Optionally, the control unit 300 may be provided with an alarm module, and a safe range of liquid inlet distance may be pre-stored, for example, 30 mm to 60 mm. If the liquid inlet distance detected by the control unit 300 exceeds the safe range, an alarm prompt may be issued, such as a sound prompt or a light prompt, etc., which is not specifically limited in the embodiment of the present invention. The control unit 300 may also adjust the position of the crucible 110 to ensure that the distance between the liquid surface of the molten silicon monocrystalline 20 in the crucible 110 and the bottom 120a of the guide tube 120 is within the safe range, and further obtain and detect the specific value of the liquid inlet distance.

[0070] Based on the same inventive concept, an embodiment of the present invention provides a method for controlling the growth of single crystal silicon. Fig.10 1 is a flow chart of a growth control method of single crystal silicon provided by an embodiment of the present invention, the growth control method comprising:

[0071] S110, controlling the image acquisition unit to acquire a liquid surface image of the molten single crystal silicon.

[0072] Among them, the single crystal silicon growth system includes a single crystal silicon growth device, which is used to carry silicon raw materials and prepare single crystal silicon by adjusting factors such as temperature and pressure. Specifically, the single crystal silicon growth device includes a crucible and a guide tube. The crucible can be used to carry molten single crystal silicon, and its stable liquid surface can form a reflecting surface. And the surface temperature of the molten single crystal silicon is generally above 1400°C, and radiant light will be spontaneously generated. The specific temperature of the molten single crystal silicon in the crucible is not specifically limited in the embodiment of the present invention. The guide tube can be understood as a heat shield. The presence of the guide tube can guide inert gases such as argon to flow in a directional manner, ensuring that the molten single crystal silicon in the crucible is always filled with argon, so that the single crystal silicon grows under the protection of the surrounding atmosphere.

[0073] Furthermore, the single crystal silicon growth device also includes a bracket, which is mechanically connected to the crucible and the guide tube, respectively, that is, the bracket can support the crucible and the guide tube, and the bracket can also adjust the position of the crucible and the guide tube. Specifically, the bracket is used to support the guide tube to be suspended in the crucible. For different single crystal silicon growth systems, the setting shape and position of the bracket can be adaptively adjusted, and the setting of the bracket is used to fix and adjust the position of the crucible and the guide tube, which is not specifically described in the embodiment of the present invention.

[0074] Furthermore, the radiation light of the molten silicon monocrystalline will illuminate the side of the guide tube close to the crucible, that is, the radiation light will illuminate the bottom of the guide tube. The side of the bottom close to the crucible includes a reflective structure, which will reflect the illuminated bottom to the liquid surface of the molten silicon monocrystalline, that is, a reflection of the bottom will be formed on the liquid surface.

[0075] Among them, the radiant light transmitted to the bottom will be transmitted to the liquid surface of the molten single crystal silicon through reflection. The bottom must have reflective properties to ensure the reflection effect of the radiant light. Specifically, when the material of the guide tube has reflective properties, the reflective structure at the bottom can be the main structure of the guide tube, and there is no need to add an additional film layer structure for achieving reflection. Furthermore, a reflective layer can be added to the bottom of the guide tube. The reflective layer can achieve the reflection effect of light, and the reflective layer is a reflective structure, which is used to ensure that the radiant light will be transmitted to the liquid surface of the molten single crystal silicon through the reflective layer.

[0076] Among them, the bottom of the guide tube includes a first hole and a second hole, and the first hole and the second hole penetrate the bottom. The radiated light can continue to be transmitted through the first hole and the second hole, and there is a reflective structure where the first hole and the second hole are not set. The radiated light transmitted to the reflective structure will be reflected to the liquid surface of the molten single crystal silicon.

[0077] S120. Determine the distance between the liquid surface of the molten silicon single crystal and the guide tube according to the liquid surface image.

[0078] Furthermore, the single crystal silicon growth system also includes an image acquisition unit, which is used to shoot and acquire images. Optionally, the image acquisition unit includes a digital camera. The image acquisition unit is located on the side of the bottom away from the molten single crystal silicon, and the image acquisition unit can acquire images of the molten single crystal silicon through the first hole, that is, the image acquisition unit is used to acquire image information of the molten single crystal silicon. The shape of the liquid surface image depends on the shape of the first hole. The specific shape of the first hole can be adaptively adjusted according to actual conditions, and the embodiment of the present invention does not make specific limitations on this. The radiated light of the molten single crystal silicon will illuminate the side of the guide tube close to the crucible, and the reflective structure at the bottom will reflect the illuminated bottom to the liquid surface of the molten single crystal silicon, that is, a reflection of the bottom will be formed on the liquid surface. In fact, the image acquisition unit acquires the image of the reflection at the liquid surface of the molten single crystal silicon through the first hole.

[0079] Specifically, the radiation light transmitted to the bottom will be reflected at the reflective structure and then transmitted to the liquid surface of the molten single crystal silicon. The image acquisition unit set at the first hole can capture the image of the liquid surface of the molten single crystal silicon through the first hole, that is, the liquid surface image, and capture the image of the reflection of the bottom fed back from the liquid surface. At the second hole, the radiation light provided by the molten single crystal silicon is directly emitted, so the radiation light transmitted to the second hole will not be reflected to the liquid surface of the molten single crystal silicon. Therefore, in the reflection image of the bottom fed back from the liquid surface of the molten single crystal silicon, the corresponding area of ​​the second hole is a dark area, which can be as follows Figure 2 and Figure 4 The black spot 121b1 is shown.

[0080] Furthermore, the opening area of ​​the first hole is larger than the opening area of ​​the second hole. The black spots formed by the second hole without reflection will be fed back through the image information collected by the first hole. In order to ensure the clear acquisition of the black spot position, the opening area of ​​the first hole is adjusted to be larger than the opening area of ​​the second hole. Optionally, the distance between the first hole and the second hole can be adaptively adjusted. In the actual production process, different processes are set for the liquid port distance, and the distance between the first hole and the second hole can be adjusted in a targeted manner.

[0081] Specifically, when the liquid level of the molten silicon single crystal in the crucible is Figure 1 When the position is shown, the liquid outlet distance is La, and the image information collected by the image acquisition unit is as follows Figure 2 As shown; when the liquid level of the molten single crystal silicon in the crucible is Figure 3 When the position is shown, the liquid port distance is Lb, and the image information collected by the image acquisition unit is as follows Figure 4 As shown. Combined Figure 2 and Figure 4 As shown, when the liquid level and the bottom of the molten silicon single crystal change, the position of the black spot in the corresponding collected image will change. Further, the image acquisition unit is connected to the control unit, and the control unit can judge the liquid level height of the molten silicon single crystal 20 based on the liquid level image collected by the image acquisition unit.

[0082] Furthermore, compared with the first hole and the second hole, the second hole can be understood as a short hole, and the first hole can be understood as a long hole. In the single crystal silicon growth system, in the image information acquired by the image acquisition unit through the first hole (long hole), the second hole (short hole) exists in the image information as a black spot corresponding to the short hole. Combining the long hole and the short hole, it is ensured that the image information acquired in the single crystal silicon growth system is more recognizable, which is convenient for judging the liquid mouth distance. At the same time, the setting of the first hole and the second hole at the bottom of the guide tube, that is, a simple punching design is performed on the bottom of the guide tube, has very little impact on the functional structure of the thermal shield of the guide tube, and has a smaller risk of powder contamination during the preparation process, thereby less interference with the airflow and less impact on the process conditions.

[0083] Among them, the single crystal silicon growth system provided by the embodiment of the present invention has different setting requirements for the liquid nozzle distance under different growth environments or different process requirements. Using the single crystal silicon growth system provided by the embodiment of the present invention, while ensuring that the liquid nozzle distance is set within the expected range, there is no need to replace hardware or switch processes, and only needs to adjust the target position of the black spot in the control unit (for example, on the human-computer interaction interface).

[0084] Among them, for the crystalline silicon growth system, by changing the size of the first hole and the distance between the second hole, the liquid mouth distance range can be adjusted to meet the needs of more process conditions and actual production environments. In other words, according to the actual liquid mouth distance range requirements, the distance between the first hole and the second hole can be adjusted accordingly to ensure the detection of the liquid mouth distance by the crystalline silicon growth system.

[0085] Optionally, the control unit and the image acquisition unit may be electrically connected or communicatively connected. The specific connection mode is not specifically displayed in the embodiment of the present invention.

[0086] In summary, the embodiment of the present invention provides a growth control method for single crystal silicon, the growth control method comprising: controlling an image acquisition unit to obtain a liquid surface image of molten single crystal silicon; and then judging the distance between the liquid surface of the molten single crystal silicon and the guide tube according to the liquid surface image. The single crystal silicon growth system is simplified while ensuring accurate judgment of the liquid inlet, and the combination of accurate liquid inlet distance is beneficial to improving the defect control of single crystal silicon.

[0087] Furthermore, Fig.11 is a flow chart of another method for controlling the growth of single crystal silicon provided by an embodiment of the present invention, with reference to Fig.11 As shown, the growth control method also includes:

[0088] S210, controlling the image acquisition unit to acquire a liquid surface image of the molten single crystal silicon.

[0089] S220. Determine the distance between the liquid surface of the molten silicon single crystal and the guide tube according to the liquid surface image.

[0090] S230. Adjust the position of the crucible according to the distance.

[0091] The control unit determines the distance between the single crystal silicon and the bottom of the guide tube, i.e., the liquid mouth distance, according to the signal transmitted by the light receiving unit. If the determined liquid mouth distance does not meet the expected setting range, the liquid mouth distance can be further adjusted by adjusting the position of the crucible, and further judgment can be made in combination with the re-collected liquid surface image, so as to ensure that the liquid mouth distance meets the required range, and the data of the liquid mouth distance can be obtained and judged in a timely manner.

[0092] Optionally, the control unit may be provided with an alarm module, and a safe range of liquid-mouth distance may be pre-stored, for example, 30 mm to 60 mm. If the liquid-mouth distance detected by the control unit exceeds the safe range, an alarm prompt may be issued, such as a sound prompt or a light prompt, etc., which is not specifically limited in the embodiment of the present invention. The control unit may also adjust the position of the crucible to ensure that the distance between the liquid level of the single crystal silicon in the crucible and the bottom of the guide tube is within the safe range, and further obtain and detect the specific value of the liquid-mouth distance.

[0093] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A single crystal silicon growth system, characterized in that: It includes a single crystal silicon growth device, an image acquisition unit and a control unit; The single crystal silicon growth device comprises a crucible, a guide tube and a bracket, wherein the bracket is mechanically connected to the crucible and the guide tube respectively, and the bracket is used to support the guide tube to be suspended in the crucible; the crucible is used to carry molten single crystal silicon, the molten single crystal silicon spontaneously generates radiation light, and the radiation light is transmitted to the bottom of the guide tube; the bottom comprises a reflective structure on a side close to the crucible, and the guide tube further comprises a first hole and at least one second hole, and the first hole and the second hole penetrate the bottom; wherein the opening area of ​​the first hole is larger than the opening area of ​​the second hole; Reflecting the radiation light to the liquid surface of the molten single crystal silicon at the reflection structure, and emitting the radiation light at the second hole; The image acquisition unit acquires a liquid surface image of the molten single crystal silicon through the first hole; The control unit is connected to the image acquisition unit, and the control unit determines the distance between the liquid level of the molten silicon single crystal and the guide tube according to the liquid level image.

2. The single crystal silicon growth system according to claim 1, characterized in that: The first hole includes a first opening and a second opening, the first opening is located on a side of the bottom away from the crucible, the second opening is located on a side of the bottom close to the crucible, and a projection of the first opening onto the crucible is located away from a projection of the second opening onto the crucible away from a projection of the second hole onto the crucible.

3. The single crystal silicon growth system according to claim 2, characterized in that: The first hole comprises a first side edge, the first opening and the second opening are connected by the first side edge; the first side edge extends along a first direction; A line connecting the center of the image acquisition unit and the first hole extends along the first direction.

4. The single crystal silicon growth system according to claim 1, characterized in that: Along the second direction, the length of the first hole is L1, and the length of the second hole is L2; Wherein, L1≥2L2, L1 and L2 are positive numbers, and the second direction is the direction from the first hole to the second hole.

5. The single crystal silicon growth system according to claim 1, characterized in that: Along the third direction, the width of the first hole is W1, and the width of the second hole is W2; Wherein, W1≥W2, W1 and W2 are positive numbers, and the third direction is perpendicular to the direction from the first hole to the second hole.

6. The single crystal silicon growth system according to claim 1, characterized in that: The material of the bottom of the guide tube includes reflective material.

7. The single crystal silicon growth system according to claim 1, characterized in that: The image acquisition unit includes a digital camera.

8. The single crystal silicon growth system according to claim 1, characterized in that: The control unit is connected to the bracket and is used for adjusting the position of the crucible through the bracket.

9. A method for controlling the growth of single crystal silicon, applied to the single crystal silicon growth system according to any one of claims 1 to 8, the single crystal silicon growth system comprising: A single crystal silicon growth device, an image acquisition unit and a control unit; the single crystal silicon growth device comprises a crucible, a guide tube and a bracket, the bracket is mechanically connected to the crucible and the guide tube respectively, and the bracket is used to support the guide tube to be suspended in the crucible; the crucible is used to carry molten single crystal silicon, and the molten single crystal silicon spontaneously generates radiant light; the bottom of the guide tube near the crucible includes a reflective structure on one side, and the guide tube also includes a first hole and at least one second hole, and the first hole and the second hole pass through the bottom; wherein the opening area of ​​the first hole is larger than the opening area of ​​the second hole; characterized in that the control method comprises: Controlling the image acquisition unit to acquire the liquid surface image of the molten silicon monocrystalline; transmitting the radiation light to the bottom, reflecting the radiation light to the liquid surface of the molten silicon monocrystalline at the reflection structure, and emitting the radiation light at the second hole; The distance between the liquid surface of the molten silicon single crystal and the guide tube is determined according to the liquid surface image.

10. The growth control method according to claim 9, characterized in that: Judging the distance between the liquid surface of the molten silicon single crystal and the guide tube according to the liquid surface image, the method further comprises: According to the distance, the position of the crucible is adjusted.

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