A flow guide structure applied to a hot field of a single crystal furnace and a single crystal furnace

Abstract

The utility model discloses a kind of flow guide structure and single crystal furnace applied to single crystal furnace hot field.The flow guide structure can include: flow guide cylinder and flow guide component, wherein, flow guide component includes first flow guide part and second flow guide part, first flow guide part extends from the outer periphery of the lower end opening of flow guide cylinder in the direction of radial away from the central axis of flow guide cylinder and simultaneously downwardly inclined relative to the lower end opening outer periphery of flow guide cylinder, second flow guide part extends from the extension end of first flow guide part in the direction of radial away from the central axis of flow guide cylinder and simultaneously upwardly inclined relative to first flow guide part.The flow guide structure can accelerate the argon flow rate passing through liquid surface, to take away more oxygen impurities, reduce the oxygen content of drawn single crystal silicon rod.

Description

Technical Field

[0001] This utility model relates to a flow guiding structure for use in the hot zone of a single crystal furnace and a single crystal furnace. Background Technology

[0002] In the Czochralski silicon single crystal growth process, the main function of the flow guide tube is to shield external heat and guide the argon gas flow towards the liquid surface in the crucible, thereby carrying away some of the heat released during crystallization and oxygen impurities volatilized from the liquid surface. Existing flow guide tubes have a relatively large space between the bottom and the silicon liquid surface in the crucible. This large space causes the argon gas flow rate to gradually slow down and disperse, resulting in a lower amount of oxygen impurities carried away by the argon gas. These oxygen impurities can easily enter the single crystal silicon, affecting its quality. Utility Model Content

[0003] In view of this, the present invention provides a flow guiding structure for use in the hot zone of a single crystal furnace and a single crystal furnace. The flow guiding structure can accelerate the flow rate of argon gas passing through the liquid surface, remove more oxygen impurities, and reduce the oxygen content of the pulled single crystal silicon rod.

[0004] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0005] In a first aspect, embodiments of this utility model provide a flow guiding structure for use in the hot zone of a single crystal furnace, comprising: a flow guiding cylinder and a flow guiding assembly, wherein,

[0006] The flow guiding component is disposed at the bottom of the flow guiding tube;

[0007] The drainage assembly includes a first drainage section and a second drainage section, wherein,

[0008] The first drainage portion extends radially away from the central axis of the guide tube from the outer periphery of the lower opening of the guide tube, and is inclined downward relative to the outer periphery of the lower opening of the guide tube.

[0009] The second drainage section extends radially from the extended end of the first drainage section away from the central axis of the guide tube and is inclined upward relative to the first drainage section.

[0010] In a second aspect, the present invention provides a single crystal furnace, comprising: the flow guiding structure applied to the hot field of the single crystal furnace provided in the first aspect embodiment above.

[0011] The first aspect of the above-mentioned utility model has the following advantages or beneficial effects:

[0012] The present invention provides a flow guiding structure for use in the hot zone of a single crystal furnace. The structure includes a first flow guiding part extending radially away from the central axis of the flow guiding cylinder from the outer periphery of the lower opening of the flow guiding cylinder, while simultaneously tilting downwards relative to the outer periphery of the lower opening. A second flow guiding part extends radially away from the central axis of the flow guiding cylinder from the extended end of the first flow guiding part, while simultaneously tilting upwards relative to the first flow guiding part. This combined structure of the first and second flow guiding parts, on the one hand, blocks the space between the crucible and the outside of the flow guiding cylinder, allowing argon gas to flow through the surface of the silicon melt in the crucible, thus carrying away more oxygen impurities from the silicon melt and preventing a large amount of argon gas from diffusing directly from the lower end of the flow guiding cylinder to the outside. On the other hand, by blocking the space between the crucible and the outside of the flow guiding cylinder through the combined first and second flow guiding parts, a relatively narrow space is created above the surface of the silicon melt. Argon gas entering this narrow space from the flow guiding cylinder increases the argon gas flow rate, further increasing the argon gas renewal rate on the surface of the silicon melt, thereby carrying away more oxygen impurities from the silicon melt.

[0013] Furthermore, the design incorporates a first guide section that extends radially away from the central axis of the guide tube from the outer periphery of the lower opening of the guide tube, while simultaneously tilting downward relative to the outer periphery of the lower opening of the guide tube. This guides the argon gas to flow radially across the liquid surface. A second guide section extends radially away from the central axis of the guide tube from the extended end of the first guide section, while simultaneously tilting upward relative to the first guide section. This allows the argon gas to flow across the surface of the silicon melt and diffuse towards the edge, preventing the argon gas from being blown vertically into the silicon melt and agitating it. It also reduces fluctuations in the silicon melt surface, thereby avoiding the impact of silicon melt agitation on crystallization.

[0014] In addition, by combining the first and second flow guides in the flow guide assembly, the space between the crucible and the outside of the flow guide tube is blocked, preventing the heat of the silicon melt from diffusing into the space outside the flow guide tube. This reduces the temperature of the lower part of the flow guide tube, increases the longitudinal temperature gradient of the flow guide tube, and facilitates the flow guide tube to absorb heat from the crystal rod. This also helps to improve the crystal rod cooling effect, thereby increasing the crystal rod pulling rate and crystal rod quality, and is helpful for pulling large-size single crystal silicon rods.

[0015] Furthermore, the first and second guide sections of the guiding assembly work together to prevent the heat of the silicon melt from diffusing into the space outside the guiding cylinder and to reflect the heat of the silicon melt back into the silicon melt. This helps to reduce the temperature gradient of the silicon melt in the vertical direction, reduces the convection between the upper and lower silicon melts caused by the temperature gradient, and helps to slow down the reaction between the silicon melt and the crucible, thereby reducing the amount of oxygen entering the silicon melt from the crucible and further reducing the oxygen content of the pulled crystal rod. In addition, the cooperation of the first and second guide sections of the guiding assembly reduces the heat loss of the silicon melt, making the silicon melt temperature more stable. This is beneficial to improving the quality of the pulled single crystal silicon rod and can reduce the energy consumed in heating the silicon melt, thus helping to reduce the production cost of single crystal silicon rods. Attached Figure Description

[0016] Figure 1 This is a cross-sectional schematic diagram showing the relative relationship between the flow guiding structure and the crucible in an existing single crystal furnace, as well as the direction of the argon flow.

[0017] Figure 2 This is a cross-sectional schematic diagram showing the relative relationship between the flow guiding structure and the crucible in a single crystal furnace, and the direction of the argon flow, according to an embodiment of this utility model.

[0018] Figure 3 This is a front view of the flow-guiding structure in a single crystal furnace according to an embodiment of the present invention;

[0019] Figure 4 This is a side view of the flow-guiding structure in a single crystal furnace according to an embodiment of the present invention;

[0020] Figure 5 This is a top view of the flow-guiding structure in a single crystal furnace according to an embodiment of the present invention;

[0021] Figure 6 This is a bottom view of the first structure of the flow guiding structure in the single crystal furnace provided according to the embodiments of this utility model;

[0022] Figure 7 This is a bottom view of the second structure of the flow guiding structure in the single crystal furnace provided according to an embodiment of the present utility model;

[0023] Figure 8 This is an exploded cross-sectional view of the detachable connection structure between the flow guide tube and the flow diversion component in a single crystal furnace according to an embodiment of this utility model.

[0024] Figure 9 The diagram shows a simulation of the gas velocity distribution in the bottom region of a prior art conduit.

[0025] Figure 10 The shown has Figure 3 The simulation diagram shows the gas velocity distribution in the bottom region of the flow guiding structure of the flow guiding component.

[0026] The attached figures are labeled as follows:

[0027] 10-Guide tube; 20-Drainage assembly; 21-First drainage section; 211-First groove; 212-First assembly section; 213-First inner circle; 214-First outer circle; 22-Second drainage section; 221-Second groove; 222-Second inner circle; 223-Second outer circle; 30-Crucible. Detailed Implementation

[0028] Czochralski (CZ) silicon production using a single-crystal furnace composed of various important components is currently the most widely used technology for producing single-crystal silicon. For example, the important components required to construct a single-crystal furnace may include the furnace body, water-cooled heat shield, flow guide tube, heater, and crucible. The flow guide tube plays two main roles: firstly, it controls heat conduction; its structure affects the axial temperature distribution of the growing single-crystal silicon rod and the vertical temperature distribution of the silicon melt in the crucible (aligned with the axial direction of the growing single-crystal silicon rod). Secondly, the structure of the flow guide tube also affects the oxygen impurity content in the single-crystal silicon rod. This is because the flow guide tube directs inert gas (such as argon, which is commonly used in single-crystal furnaces) to the surface of the silicon melt in the crucible, carrying away not only some of the heat released during crystallization but also oxygen impurities volatilized from the silicon melt. In particular, for flow guide tubes with an inverted frustum structure… Figure 1 An exemplary schematic diagram illustrates the relative relationship between the flow guide tube 10 and the crucible 30 in a conventional single-crystal furnace. From Figure 1 It can be seen that the bottom of the existing guide tube 10 (close to the surface of the silicon melt) is an upward-sloping arc structure. The purpose is to guide the argon gas Ar passing over the surface of the silicon melt to quickly change its flow direction along the arc structure (that is, the upward-sloping arc structure designed at the bottom of the existing guide tube 10 can change the flow direction of argon gas Ar from downward towards the silicon melt to upward). The gas flow carrying oxygen impurities rises over the crucible wall and carries the oxygen impurities away from the silicon solution area. While removing heat and oxygen impurities, it avoids the argon gas Ar flow from causing eddies or fluctuations in the silicon melt, so as to meet the growth environment of single crystal silicon and realize the direct pulling of single crystal silicon rods Si. However, the existing upward-sloping arc structure at the bottom of the guide tube 10 has several drawbacks. First, it results in poor contact between the argon gas (Ar) and the surface of the molten silicon, limiting the amount of oxygen impurities it carries away. Second, while it carries away heat from the surface of the molten silicon, the design of the bottom of the guide tube 10 creates a large heat dissipation space above the molten silicon, increasing heat dissipation and leading to a large temperature gradient in the vertical direction of the molten silicon. This causes strong convection between the molten silicon and the crucible, resulting in a strong reaction between the molten silicon and the crucible, which in turn increases the amount of oxygen impurities entering the molten silicon from the crucible.

[0029] To address the aforementioned problems with existing flow guide tubes, this invention provides a flow guide structure and a single crystal furnace applicable to the hot zone of a single crystal furnace.

[0030] The following will describe in detail the flow guiding structure applied to the hot zone of the single crystal furnace and the specific structure of the single crystal furnace provided in the embodiments of this utility model.

[0031] in, Figure 2 This is a cross-sectional schematic diagram showing the relative relationship between the flow guiding structure and the crucible in a single crystal furnace, and the direction of the argon flow, according to an embodiment of this utility model. Figure 3 This is a front view of the flow-guiding structure in a single crystal furnace according to an embodiment of the present invention; Figure 4 This is a side view of the flow-guiding structure in a single crystal furnace according to an embodiment of the present invention; Figure 5 This is a top view of the flow-guiding structure in a single crystal furnace according to an embodiment of the present invention; Figure 6 This is a bottom view of the first structure of the flow guiding structure in the single crystal furnace provided according to the embodiments of this utility model; Figure 7 This is a bottom view of the second structure of the flow guiding structure in the single crystal furnace provided according to an embodiment of the present utility model; Figure 8 This is an exploded cross-sectional view of the detachable connection structure between the flow guide tube and the flow diversion component in a single crystal furnace according to an embodiment of the present invention.

[0032] It is worth noting that the directional terms "upper" and "lower" used in the embodiments of this utility model are described in the context of the structure being applied to a single crystal furnace. For example, "upper" refers to the direction opposite to the direction of gravity in the axial direction of the single crystal furnace, and "lower" refers to the direction pointing towards gravity in the axial direction of the single crystal furnace.

[0033] Furthermore, the directional terms "inner" and "outer" used in this utility model describe the structure in the context of its application in a single crystal furnace. "Inner" refers to the area close to the central axis of the single crystal furnace, and "outer" refers to the area away from the central axis. "Inward" refers to a radial direction from the central axis away from the furnace towards the central axis, and "outward" refers to a radial direction from the central axis close to the furnace towards the central axis. It should be noted that within the single crystal furnace, components such as the flow guide tube and crucible are coaxially installed and used with the furnace; therefore, the central axis of the single crystal furnace is equivalent to the central axis of the flow guide tube, crucible, and other components.

[0034] Specifically, such as Figures 2 to 8 As shown, the flow guiding structure for the hot zone of a single crystal furnace provided in this embodiment of the invention may include: a flow guiding cylinder 10 and a flow guiding assembly 20. Wherein,

[0035] The flow guiding component 20 is located at the bottom of the flow guiding tube 10;

[0036] The flow guiding assembly 20 includes a first flow guiding section 21 and a second flow guiding section 22. The first flow guiding section 21 extends radially away from the central axis of the guide tube 10 from the outer periphery of the lower opening of the guide tube 10 and is inclined downward relative to the outer periphery of the lower opening of the guide tube 10. The second flow guiding section 22 extends radially away from the central axis of the guide tube 10 from the extended end of the first flow guiding section 21 and is inclined upward relative to the first flow guiding section 21. The direction away from the central axis of the guide tube 10 also points towards the side wall of the crucible 30 within the hot zone of the single crystal furnace. Therefore, the flow guiding assembly 20 is used to guide argon gas through the space between the flow guiding assembly 20 and the surface of the silicon melt in the crucible 30, thereby optimizing the argon gas flow through this space.

[0037] It is worth noting that the accompanying drawings provided in this embodiment of the present invention are merely illustrative examples illustrating the relative positional relationship between the crucible 30 in the single crystal furnace and the flow guiding cylinder 10 and the flow guiding component 20 in the flow guiding structure, as well as the relative position and connection relationship between the flow guiding cylinder 10 and the flow guiding component 20. For the structures of other components in the single crystal furnace, such as the water-cooled heat shield, the insulation cylinder, the heater, etc., and the relative positional relationships between other components and the crucible 30 and the flow guiding cylinder 10, existing structural designs can be followed, or the relative relationships between the various components in the single crystal furnace can be adjusted according to user requirements. In other words, the flow guiding structure provided by this invention can directly replace the existing flow guiding cylinder in a current single crystal furnace, or it can be applied to a newly designed single crystal furnace with a novel structure.

[0038] Furthermore, the argon gas Ar provided in this invention is merely an example of an inert gas commonly used in single crystal furnaces. This argon gas Ar can also be replaced with other inert gases without affecting the flow guiding structure and the final design of the single crystal furnace provided in this invention.

[0039] Understandably, the flow guiding structure provided in this embodiment of the present invention achieves the purpose of guiding the flow of inert gas and controlling heat conduction by cooperating with the flow guiding tube 10 and the flow guiding component 20.

[0040] against Figures 1 to 8 The flow guiding structure shown is applied to the hot zone of a single crystal furnace. Its flow guiding component 20 is closer to the surface of the silicon solution in the crucible 30 than the bottom of the flow guiding cylinder 10. Through the cooperation of the first flow guiding part and the second flow guiding part, on the one hand, it can guide the argon gas flow through the surface of the silicon melt in the crucible 30, and carry away more oxygen impurities in the silicon melt, avoiding a large amount of argon gas directly diffusing from the lower end of the flow guiding cylinder 10 to the outside of the flow guiding cylinder 10; on the other hand, it makes a relatively narrow space above the surface of the silicon melt. When argon gas enters the relatively narrow space from the flow guiding cylinder 10, the flow rate of argon gas Ar will increase, which can further increase the argon gas renewal rate on the surface of the silicon melt, thereby carrying away more oxygen impurities in the silicon melt.

[0041] In addition, the first and second flow-guiding parts of the flow-guiding assembly 20 block the space between the crucible 30 and the outside of the flow-guiding cylinder 10, preventing the heat of the silicon melt from diffusing into the space outside the flow-guiding cylinder 10. This reduces the temperature of the lower part of the flow-guiding cylinder 10, increases the longitudinal temperature gradient of the flow-guiding cylinder 10, and facilitates the flow-guiding cylinder 10 to absorb heat from the crystal rod. This improves the crystal rod crystallization cooling effect, thereby increasing the crystal rod pulling rate and crystal rod quality, and helps to pull large-size single-crystal silicon rods.

[0042] Furthermore, the guiding component 20, by preventing the heat of the silicon melt from diffusing into the space outside the guiding cylinder 10 and by reflecting the heat of the silicon melt back into the silicon melt, helps to reduce the temperature gradient of the silicon melt in the vertical direction. This reduces the convection between the upper and lower silicon melts caused by the temperature gradient, which helps to slow down the reaction between the silicon melt and the crucible, thereby reducing the amount of oxygen entering the silicon melt from the crucible and further reducing the oxygen content of the pulled crystal rod. In addition, by reducing the heat loss of the silicon melt through the guiding component 20, the temperature of the silicon melt is made more stable, which is beneficial to improving the quality of the pulled single crystal silicon rod and reducing the energy consumed in heating the silicon melt, thus helping to reduce the production cost of single crystal silicon rods.

[0043] The relative relationship between the drainage component 20 and the guide tube 10 can be: the drainage component 20 and the guide tube 10 are an integral structure; or the drainage component 20 and the guide tube 10 can be detachably connected. Preferably, the drainage component 20 and the guide tube 10 are detachably connected, which facilitates the replacement of damaged parts and improves the recycling rate of the drainage component 20 or the guide tube 10.

[0044] Additionally, regarding the flow guide tube 10, such as Figure 2 As shown, the flow guide tube 10 is generally an inverted frustum structure with vertically penetrating holes. The vertically penetrating holes serve as the passageways for the single-crystal silicon rod during the pulling process. The lower opening of the flow guide tube 10 points to the bottom of these vertically penetrating holes. This inverted frustum structure flow guide tube 10, in conjunction with the flow guiding component 20, helps to reduce the temperature of the single-crystal silicon rod near the crucible 30, increases the temperature gradient in the vertical direction of the single-crystal furnace (i.e., the axial direction of the single-crystal silicon rod), and increases the crystallization rate of the silicon melt, thereby increasing the pulling rate of the single-crystal silicon rod and facilitating the production of large-size single-crystal rods. It is worth noting that the vertically penetrating inverted frustum structure flow guide tube 10 used in this embodiment can be an existing flow guide tube; that is, the flow guiding structure provided in this embodiment can be obtained by directly assembling the flow guiding component 20 provided in this embodiment onto an existing flow guide tube 10.

[0045] It is worth noting that, in the structure provided by this embodiment of the utility model, in addition to the structure of the flow guide tube 10, the structure of the flow guide component 20 and its relative relationship with the flow guide tube 10 will have a significant impact on the quality of the pulled single crystal silicon rod, the temperature distribution in the single crystal furnace, the argon gas flow, and the temperature of the silicon melt in the crucible 30. The structure of the flow guide component 20 and its relative relationship with the flow guide tube 10 will be described in detail below.

[0046] The first drainage portion 21 extends radially away from the central axis of the guide tube 10 from the outer periphery of the lower end opening of the guide tube 10, and simultaneously slopes downward relative to the outer periphery of the lower end opening of the guide tube 10, such that the first drainage portion 21 extends into a shape similar to the side surface of a frustum. Specifically, as shown... Figure 3 , Figures 5 to 8 As shown, the first drainage part 21 has an upper opening of the first inner circle 213 and a lower opening of the first outer circle 214. The upper opening of the first inner circle 213 (hereinafter referred to as the first inner circle 213) and the lower opening of the first outer circle 214 (hereinafter referred to as the first outer circle 214) are connected.

[0047] The flow guiding assembly 20 includes a first flow guiding part 21 that extends radially away from the central axis of the flow guiding cylinder 10 from the outer periphery of the lower opening. The diameter of the first inner circle 213 of the first flow guiding part 21 is smaller than the diameter of the first outer circle 214. The first inner circle 213 is located at the outer periphery of the lower opening of the flow guiding cylinder 10 and matches the outer periphery of the lower opening of the flow guiding cylinder 10. The first outer circle 213 is located between the bottom of the flow guiding cylinder 10 and the surface of the silicon solution in the crucible 30. The distance between the first flow guiding part 21 and the surface of the silicon solution in the crucible 30 is smaller than the distance between the bottom of the flow guiding cylinder 10 and the surface of the silicon solution in the crucible 30, so as to guide the argon gas Ar to move towards the surface of the silicon melt and allow the argon gas Ar to contact the surface of the liquid more.

[0048] Among them, such as Figure 8 As shown, the first inner circle 213 is located at the outer periphery of the lower opening of the guide tube 10 and matches the outer periphery of the lower opening of the guide tube 10, so that the connection position of the first inner circle 213 of the first guide part 21 and the outer periphery of the lower opening of the guide tube 10 forms a seal, so as to prevent argon gas from flowing out from the connection position of the first guide part 21 and the guide tube 10.

[0049] Among them, such as Figure 8As shown, the first guide section 21 is inclined downward relative to the outer periphery of the lower end opening of the guide tube 10, so that the first outer circle 214 of the first guide section 21 is located below the first inner circle 213. In the radial direction from the inside to the outside, the distance between the first guide section 21 and the surface of the silicon solution in the crucible 30 gradually decreases. According to Bernoulli's principle, the flow rate of the argon gas gradually increases in the radial direction from the inside to the outside. On the one hand, the argon gas can quickly carry away the oxygen impurities in the area. On the other hand, the argon gas on the outside is faster than the argon gas on the inside, which can make the argon gas on the outside leave the area faster than the argon gas on the inside, avoiding the turbulence caused by the accumulation of argon gas on the inside and reducing the interference of the argon gas on the surface of the silicon solution in the crucible 30.

[0050] from Figure 2 It can be seen that the first inner circle 213 and the first outer circle 214 of the first drainage section 21 are inclined downwards. This first drainage section 21 allows for a narrower space between the first drainage section 21 and the liquid surface. This narrower space increases the flow rate of argon gas across the liquid surface, meaning that the amount of argon gas passing through the liquid surface per unit time increases, which is more conducive to removing more oxygen impurities. Furthermore, as... Figure 2 As shown, the first guide section 21 has a downward-sloping side, which can exert more force on the argon gas (Ar) towards the liquid surface, causing the argon gas to flow more towards the liquid surface and form better contact with it, thereby carrying away more oxygen impurities. Furthermore, the design of the downward-sloping side structure of the first guide section 21, combined with the structure of the second guide section 22 which folds away from the liquid surface from the outer side away from the first guide section 21, ensures that although the first guide section 21 exerts more force on the argon gas towards the liquid surface, it can also increase the flow rate of the argon gas across the liquid surface. Additionally, the second guide section 22 guides the argon gas upward, reducing its residence time on the liquid surface. This design of the downward-sloping side structure in conjunction with the second guide section 22 can prevent fluctuations in the liquid surface.

[0051] Specifically, regarding the structure where the drainage component 20 and the guide tube 10 are detachably connected, such as... Figure 8 As shown, a first assembly portion 212 is provided on the edge of the first inner circle 213 of the first drainage portion 21; a second assembly portion 11 is provided on the bottom of the guide tube 10; the first assembly portion 212 and the second assembly portion 11 cooperate to fix the first drainage portion 21 to the bottom of the guide tube 10. Exemplarily, the first assembly portion 212 and the second assembly portion 11 can be assembled by a snap-fit ​​method. The cooperation between the first assembly portion 212 and the second assembly portion 11 facilitates the disassembly, assembly, and replacement of the drainage assembly 20 and the guide tube 10.

[0052] The first assembly part 212 may include a cylindrical part extending upward from the first inner circle 213 of the first guide part 21 and a flange structure provided on the cylindrical part. The cylindrical part extends into the lower end opening of the guide tube 10 from below. The second assembly part 11 may be a groove circumferentially provided on the inner wall of the lower end opening of the guide tube 10. When the cylindrical part extends into the lower end opening of the guide tube 10 from below, the flange structure on the cylindrical part can be inserted into the groove to realize the assembly of the first assembly part 212 and the second assembly part 11.

[0053] Furthermore, regarding the aforementioned first drainage portion 21, the diameter of its first outer circle 214 ( Figure 8 The diameter D1 can be 380mm to 800mm. For example, the diameter of the first outer circle 214 can be 380mm, 400mm, 500mm, 700mm, or 800mm, etc. In addition, the height difference between the first outer circle 214 and the first inner circle 213 ( Figure 8 The indicated height H (which refers to the vertical distance from the top to the bottom of the inclined surface) can be 0.1 mm to 20 mm. For example, the height can be 0.1 mm, 1 mm, 5 mm, 10 mm, 15 mm, or 20 mm, etc. Preferably, the diameter of the first outer circle 214 is slightly smaller than the outer diameter of the guide tube 10 it is adapted to. By controlling the diameter of the first outer circle 214 and the height difference between the first outer circle 214 and the first inner circle 213, the flow direction of argon gas Ar can be controlled.

[0054] Additionally, the width of the second drainage section 22 (e.g.) Figure 8 As shown, the width K of the second drainage section 22 (referring to the distance from the connection position of the second drainage section 22 with the first drainage section 21 to the outer side of the second drainage section 22) can be 20mm to 210mm. For example, the width K of the second drainage section 22 can be 20mm, 30mm, 50mm, 80mm, 100mm, 120mm, 150mm, 180mm, 200mm or 210mm, etc. By designing the width of the second drainage section 22 in conjunction with the first drainage section 21, the purpose of guiding the flow of fluid can be achieved.

[0055] In addition, by matching the dimensions (height and diameter) of the first flow guide 21 with the width of the second flow guide 22, it can be ensured that the argon gas flow passes through the surface of the silicon melt in the crucible 30, and that the argon gas flow will not cause large fluctuations in the surface of the silicon melt when the silicon melt level is relatively high.

[0056] It is worth noting that the shape of the first flow-guiding part 21 is not necessarily related to the inverted frustum structure of the flow-guiding tube 10.

[0057] In addition, such as Figure 8As shown, the outer diameter D2 of the cylindrical portion of the first assembly portion 212 of the first drainage portion 21 is generally 300mm to 400mm. For example, the outer diameter of the cylindrical portion of the first assembly portion 212 can be 300mm, 350mm, 380mm, or 400mm, etc. The outer diameter D2 of the cylindrical portion of the first assembly portion 212 of the first drainage portion 21 can be the same as the inner diameter of the lower edge of the guide tube 10.

[0058] The second drainage section 22 extends radially away from the central axis of the guide tube 10 from the extended end of the first drainage section 21, and at the same time tilts upward relative to the first drainage section 21, so that the second drainage section 22 extends into a shape similar to the side of an inverted frustum. Specifically, as shown in the figure... Figure 3 , Figures 5 to 8 As shown, the second drainage portion 22 has a lower opening of the second inner circle 222 and an upper opening of the second outer circle 223, and the lower opening of the second inner circle 222 (hereinafter referred to as the second inner circle 222) and the upper opening of the second outer circle 223 (hereinafter referred to as the second outer circle 223) are connected.

[0059] Among them, such as Figure 3 , Figures 5 to 8 As shown, the second drainage section 22 extends radially from the extended end of the first drainage section 21 away from the central axis of the guide tube 10, such that the diameter of the second outer circle 223 is larger than the diameter of the second inner circle 222, and the second inner circle 222 matches the first outer circle 214 of the first drainage section 21.

[0060] Among them, such as Figure 8 As shown, the second drainage portion 22 is inclined upward relative to the first drainage portion 21, such that the second outer circle 223 of the second drainage portion 22 is higher than the second inner circle 222. In other words, the outer side of the second drainage portion 22 away from the first drainage portion 21 folds away from the liquid surface, as shown... Figure 2 , Figure 3 and Figure 4 As shown, the height of the silicon solution surface gradually increases from the second inner circle 222 (i.e., the position connected to the first drainage section 21) to various positions on the second outer circle 223. (Refer to...) Figure 2 At the tail of the flow guide assembly 20, the argon gas flow needs to change its flow direction and flow upward around the opening of the crucible 30 to exit. The second flow guide 22 at the tail of the flow guide assembly 20 is tilted upward to better match the flow direction of the argon gas flow, so as to avoid turbulence caused by the change of flow direction of the argon gas flow at this point, which would cause fluctuations in the surface of the silicon melt at this point.

[0061] pass Figure 2 , Figure 3 and Figure 4The structure of the second flow guide 22 shown above, on the one hand, satisfies the requirement that argon gas carries away more oxygen impurities in the silicon melt, while also guiding the flow of argon gas better, avoiding agitation and fluctuation of the silicon melt surface caused by argon gas stagnation on the surface of the silicon melt; on the other hand, the second flow guide 22 is located at the tail of the flow guide assembly 20, which increases the space between the tail of the flow guide assembly 20 and the surface of the silicon solution in the crucible 30. This increases the operator's field of vision during the production of single crystal silicon rods, making it easier for the operator to observe the meniscus that appears in the junction area between the silicon melt and the single crystal silicon rod or seed crystal, or for the equipment to identify the meniscus that appears in the junction area between the silicon melt and the single crystal silicon rod or seed crystal, so as to control the pulling of single crystal silicon rods based on the meniscus.

[0062] Furthermore, regarding the structure of the second drainage section 22 mentioned above, as follows: Figure 3 , Figure 4 , Figure 6 and Figure 7 As shown, a plurality of second grooves 221 are distributed on the lower surface of the second guide section 22 (i.e., the surface facing the silicon melt in the crucible). Each second groove 221 extends from the connection position between the second guide section 22 and the first guide section 21 towards the edge of the second guide section 22 (that is, the second groove 221 extends from the second inner circle 222 to the second outer circle 223 along the radial direction of the second guide section 22). The plurality of second grooves 221 are evenly distributed along the circumference of the second guide section 22. By designing the second grooves 221 in conjunction with the structure of the first guide section 21, the first guide section 21 guides the argon gas flow through the surface of the silicon melt and increases the gas flow rate through the surface of the silicon melt to remove more oxygen impurities, while avoiding the stirring of the silicon melt and surface fluctuations caused by the excessively rapid increase in the gas flow rate through the surface of the silicon melt. In addition, the design of the second groove 221 can further improve the operator's field of vision for observing the meniscus that appears in the junction area of ​​the silicon melt and the single crystal silicon rod or seed crystal, or the equipment's field of vision for identifying the meniscus that appears in the junction area of ​​the silicon melt and the single crystal silicon rod or seed crystal, which helps to better identify the meniscus in the central region of the silicon melt.

[0063] The second groove 221 can be designed in two structures. Specifically, as follows: Figure 6 and Figure 7 As shown, the second groove 221 has a first structure: the second groove 221 is disposed on the surface of the second drain portion 22 near the surface of the silicon melt and does not penetrate the second drain portion 22, that is, the depth of the second groove 221 is less than the thickness of the second drain portion 22. The second groove 221 has a second structure: the second groove 221 penetrates the second drain portion 22 in the thickness direction.

[0064] For the first structure of the second groove 221, such as Figure 3As shown, the depth of the second groove 221 in the thickness T direction of the second drainage portion 22 is generally 0.1mm to 5mm. For example, the depth of the second groove 221 in the thickness T direction of the second drainage portion 22 can be 0.1mm, 0.5mm, 1mm, 2mm, 3mm or 5mm, etc.

[0065] Furthermore, regardless of whether it is the first structure or the second structure of the second groove 221, the width D of the second groove 221 in the circumferential direction of the first drainage portion 21 (e.g.) Figure 6 and Figure 7 (As shown) the width is 10mm to 200mm. For example, the width D of the second groove 221 in the circumferential direction of the first drainage portion 21 can be 10mm, 30mm, 50mm, 80mm, 100mm, 130mm, 150mm, 180mm or 200mm, etc.

[0066] The design of the second groove 221 helps to further reduce the surface fluctuations of the silicon melt caused by the interference of the vertically blown argon gas flow due to the small space between the second drain section 22 and the melt.

[0067] In addition, for the second structure of the second groove 221, the second drainage part 221 may include: multiple independent fan ring structures, each fan ring structure being spaced apart from each other, the gap being the second groove 221 described above, and the inner end of each fan ring structure being connected to the first drainage part 21.

[0068] Furthermore, the lower surface of the first drainage portion 21 provided by this utility model can be a smooth surface, or it can be as follows: Figure 7 As shown, the lower surface of the first flow guide 21 (the surface facing the silicon melt in the crucible) has multiple first grooves 211 spaced apart in the circumferential direction. The first grooves 211 extend radially from the first inner circle 213 to the first outer circle 214. This design of the first grooves 211 allows for adjustment of the argon gas flow rate reaching the first flow guide 21. While ensuring sufficient contact between the argon gas and the liquid surface, it further reduces liquid surface fluctuations caused by this contact, thus contributing to improved stability and reliability of single-crystal silicon growth.

[0069] It is worth noting that, such as Figure 7 As shown, the first groove 211 and the second groove 221 generally correspond to each other, that is, the second groove 221 can be regarded as an extension of the first groove 211 in the second drain portion 22. Alternatively, the first groove 211 and the second groove 221 can also be designed to be staggered.

[0070] In addition, such as Figure 2As shown, the angle α1 between the first drainage section 21 and the horizontal plane is greater than 0° and less than or equal to 30°. For example, the angle α1 can be 5°, 10°, 15°, 20° or 30°, etc. The angle α1 refers to the angle between the line connecting the first inner circle 213 and the second inner circle 214 intercepted by the longitudinal plane passing through the central axis of the guide tube 10 and the plane below it. By limiting the angle, it is beneficial to control the flow direction of argon gas Ar and the flow rate towards the liquid surface.

[0071] In addition, such as Figure 2 As shown, the angle α2 between the second drainage section 22 and the horizontal plane is greater than 30° and less than 90°. For example, the angle α2 can be 35°, 40°, 45°, 50°, 60°, 75° or 85°, etc. The angle α2 refers to the angle between the line connecting the second inner circle 222 and the second outer circle 223 intercepted by the longitudinal plane passing through the central axis of the guide tube 10 and the plane below it. By limiting the angle, it is beneficial to control the argon gas Ar to quickly move away from the liquid surface after contacting the liquid surface, thereby reducing or even avoiding liquid surface fluctuations.

[0072] Furthermore, this embodiment of the invention also provides a single crystal furnace. Specifically, the single crystal furnace may include the flow guiding structure applied to the hot zone of the single crystal furnace provided in the above embodiments.

[0073] Furthermore, in order to clearly explain Figure 1 The influence of the existing conductive tube and the flow guiding structure provided in this embodiment on the gas flow rate are respectively shown in the figure. Figure 1 The prior art conductive tube shown and having Figure 3 The model shown simulates the flow guiding structure of the flow guiding component. Figure 1 The prior art conductive tube shown and having Figure 3 The influence of the flow guiding structure of the flow guiding component shown on the flow rate inside the single crystal furnace. Figure 9 The diagram shown is a simulation of the gas velocity distribution in the bottom region of the existing conductive tube. Figure 10 The shown has Figure 3 The simulation diagram shows the gas velocity distribution in the bottom region of the flow guiding structure of the flow guiding component. From... Figure 9 It can be clearly seen that the gas flow direction is from V1 to V2, in the horizontal direction above the silicon melt surface. Figure 9 In the S1 region, the gas velocity decreases significantly. This decrease in gas velocity in the horizontal direction leads to a reduction in the gas exchange rate and a decrease in the amount of oxygen impurities that can be carried away. Furthermore, in the corner region of the existing conductive tube (…),… Figure 9In the S2 region, the gas flow velocity changes from vertical to horizontal, resulting in a significant increase. This increased gas velocity in the corner region exerts a considerable impact on the silicon molten surface, agitating the silicon and hindering the pulling of single-crystal silicon. Compared with the simulation results of existing conductive tubes, such as... Figure 10 As shown, by adding a flow guiding component 20 to the flow guiding structure, the gas flow velocity (from the V1 direction to the V2 direction) is reduced in the corner region where the flow guiding component 20 is located. Figure 10 The S2 region shown is significantly reduced (compared to) Figure 9 Compared to the S2 region, this demonstrates that the flow guiding structure provided by this invention can effectively reduce the vertical gas agitation of the silicon melt, which is beneficial to improving the quality of single-crystal silicon pulling. The gas is above the silicon melt surface ( Figure 10 The flow velocity in region S1 (as shown) is significantly increased (compared to) Figure 9 Compared to the S1 region, it is more effective at removing oxygen impurities from the silicon melt, thus improving the quality of the pulled single-crystal silicon.

[0074] The working principle of the flow guiding structure applied to the hot field of the single crystal furnace provided in the above embodiments will be described in detail below.

[0075] Specifically, such as Figure 2 As shown, the lower end of the seed crystal penetrates the guide tube 10 of the guide structure and contacts the surface of the silicon melt in the crucible 30, so that the single crystal silicon formed by the crystallization of the silicon melt grows along the seed crystal. During the growth of monocrystalline silicon into a monocrystalline silicon rod (Si), argon gas (Ar) flows downward from the guide tube 10 to the surface of the silicon melt. Under the guidance of the first guide section 21 of the guide assembly 20, the argon gas changes its flow direction (tilting downward, so that the argon gas maintains a downward flow velocity while also having a lateral flow velocity). At the same time, since the first guide section 21 blocks the space between the outside of the guide tube 10 and the surface of the silicon melt, that is, the space above the surface of the silicon melt is squeezed and narrowed by the first guide section 21, it helps to increase the flow velocity of argon gas across the surface of the silicon melt, so that the amount of argon gas in contact with the surface of the silicon melt per unit time increases, thereby carrying away more oxygen impurities. Furthermore, the second guide section 22 of the guide assembly 20 guides the argon gas to flow upward, avoiding the accumulation of argon gas in the space between the liquid surface and the first guide section 21. This can ensure the replacement rate of argon gas above the liquid surface. At the same time, avoiding the accumulation of argon gas above the liquid surface can avoid the eddies or fluctuations caused by argon gas in the silicon melt.

[0076] In addition, the first flow guide 21 blocks the space above the liquid surface. On the one hand, it can reduce the amount of heat released by the silicon melt reaching the outside of the guide tube 10, which helps to control the low temperature at the bottom of the guide tube 10 and makes the single crystal silicon rod Si have a relatively high temperature gradient in the axial direction, which is beneficial to the growth of single crystal silicon. On the other hand, the first flow guide 21 returns the heat released by the silicon melt to the silicon melt, reduces the temperature gradient of the silicon melt in the vertical direction (which is consistent with the axial direction of the single crystal silicon rod Si), reduces the vertical convection of the silicon melt caused by the temperature gradient, and thus reduces the heat loss of the silicon melt.

[0077] Furthermore, the second groove 221 provided on the second flow section 22 can, on the one hand, further integrate the flow direction and flow rate of argon gas Ar, and further avoid surface fluctuations of the silicon melt; on the other hand, it can improve the observation field of the silicon melt surface, so that users or testing equipment can observe the meniscus at the junction of the single crystal silicon rod Si and the silicon melt surface through the second groove 221, so as to control the pulling of the single crystal silicon rod Si according to the meniscus.

[0078] The above steps are provided only to help understand the method, structure, and core idea of ​​this utility model. For those skilled in the art, various improvements and modifications can be made to this utility model without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims of this utility model.

Claims

1. A flow guiding structure applied to the hot zone of a single crystal furnace, characterized in that, include: The flow guide tube (10) and the flow diversion assembly (20), wherein, The flow guiding component (20) is disposed at the bottom of the flow guiding tube (10); The drainage component (20) includes a first drainage section (21) and a second drainage section (22). The first drainage section (21) extends radially away from the central axis of the guide tube (10) from the outer periphery of the lower end opening of the guide tube (10) and is inclined downward relative to the outer periphery of the lower end opening of the guide tube (10). The second drain section (22) extends radially away from the central axis of the guide tube (10) from the extended end of the first drain section (21) and is inclined upward relative to the first drain section (21).

2. The flow guiding structure according to claim 1, characterized in that, The first drainage portion (21) extends to have the same shape as the side of the frustum; The second drainage portion (22) extends to the same shape as the side of the inverted frustum.

3. The flow guiding structure according to claim 2, characterized in that, The lower surface of the second drainage portion (22) has a plurality of second grooves (221) spaced circumferentially, and the second grooves (221) extend radially.

4. The flow guiding structure according to claim 3, characterized in that, The second groove (221) does not penetrate the second drain portion (22) in the thickness direction; or, The second groove (221) extends through the second drain portion (22) in the thickness direction.

5. The flow guiding structure according to claim 4, characterized in that, The width of the second groove (221) is 10mm~100mm; And / or, The depth of the second groove (221) is 0.1 mm to 5 mm.

6. The flow guiding structure according to claim 3, characterized in that, The lower surface of the first drainage portion (21) is provided with a plurality of first grooves (211) spaced apart in the circumferential direction, and the first grooves (211) extend in the radial direction.

7. The flow guiding structure according to claim 1, characterized in that, The angle of inclination between the first drainage part (21) and the horizontal plane is greater than 0° and less than or equal to 30°; And / or, The angle of inclination between the second drainage part (22) and the horizontal plane is greater than 30° and less than 90°.

8. The flow guiding structure according to claim 1 or 2, characterized in that, The diversion component (20) is detachably connected to the diversion tube (10).

9. The flow guiding structure according to claim 8, characterized in that, The upper edge of the first drainage part (21) is provided with a first assembly part (212). The bottom of the guide tube (10) is provided with a second assembly part (11). The first assembly part (212) cooperates with the second assembly part (11) to fix the first flow guide part (21) to the bottom of the flow guide tube (10).

10. A single crystal furnace, characterized in that, include: The flow guiding structure applied to the hot zone of a single crystal furnace as described in any one of claims 1 to 9.

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