Single crystal furnace

Abstract

The embodiment of the invention relates to the technical field of single crystal furnaces, and provides a single crystal furnace which comprises a main chamber and an auxiliary chamber, the first flow dividing disc is arranged at the throat between the main chamber and the auxiliary chamber, a first air outlet part is arranged on the end face of the end, deviating from the auxiliary chamber, of the first flow dividing disc, and the first air outlet part is used for blowing inert gas flow distributed annularly into the main chamber; the second flow dividing disc is arranged at the end, away from the main chamber, of the auxiliary chamber, at least part of the second flow dividing disc is located in the auxiliary chamber, and a second air outlet part is arranged on at least part of the peripheral wall of the second flow dividing disc and used for blowing inert gas flow distributed in the circumferential direction of the second flow dividing disc into the auxiliary chamber. The single crystal furnace provided by the embodiment of the invention at least can solve the problem of crystal oscillation of a large-size crystal bar caused by opposite blowing of airflow in the single crystal furnace in the prior art.

Description

Technical Field

[0001] This application relates to the field of single crystal furnace technology, and in particular to a single crystal furnace. Background Technology

[0002] Currently, Czochralski furnaces play a crucial role in the semiconductor and photovoltaic industries for producing high-quality monocrystalline silicon rods. Traditional Czochralski furnaces employ a four-port argon gas distribution structure in the auxiliary chamber, with argon gas ejected symmetrically at 45° angles from the four ports to ensure uniform gas distribution and control of the crystal growth environment. Simultaneously, argon gas at the throat is further enhanced through a double-port counter-blowing method, which removes oxides and other impurities from the melt surface. This technology has proven highly effective in manufacturing medium-sized crystal rods in the past, with oxygen content and other parameters meeting industry requirements.

[0003] However, with the development trend of the monocrystalline silicon industry, the demand for large-size crystal rods is increasing, and traditional auxiliary chamber and throat gas outlet structures are facing new challenges. Under high argon flow rate processes, the high-speed gas flow collision caused by the four-port gas distribution plate design easily forms turbulence. This not only affects the uniform distribution of gas but also exacerbates the wobbling during crystal rod growth, the so-called crystal wobbling phenomenon. In severe cases, it may cause abnormal crystal growth or even breakage, greatly affecting the yield and quality of the crystal rods. In addition, the dual-port counter-blowing design at the throat, due to the uneven argon flow rate and direction, leads to uneven gas coverage on the crystal rod surface, further aggravating the crystal wobbling problem. Moreover, the entrainment efficiency of oxides and impurities is reduced, affecting the purity and performance of the crystal rods. Summary of the Invention

[0004] This application provides a single crystal furnace that at least solves the problem of crystal wobbling in large-sized crystal rods caused by airflow back-blowing in the single crystal furnace in the prior art.

[0005] According to some embodiments of this application, one aspect of this application provides a single crystal furnace, including a main chamber and a secondary chamber; a first distribution plate, disposed at the throat between the main chamber and the secondary chamber, with a first gas outlet on the end face of the first distribution plate away from the secondary chamber, the first gas outlet being used to blow an inert gas flow in an annular distribution into the main chamber; and a second distribution plate, disposed at the end of the secondary chamber away from the main chamber, at least a portion of the second distribution plate being located within the secondary chamber and a second gas outlet being disposed on the outer peripheral wall of at least a portion of the second distribution plate, the second gas outlet being used to blow an inert gas flow in an circumferentially distributed along the second distribution plate into the secondary chamber.

[0006] In some embodiments, at least a portion of the first diverter plate is a conical cylinder with a diameter that gradually increases from the secondary chamber to the main chamber. At least a portion of the first diverter plate has a first end face with the largest diameter along its axial direction. The first air outlet includes a plurality of first air outlet holes, which are spaced apart on the first end face around the axial direction of the first diverter plate. The angle between the axial extension direction of the first air outlet hole and the first end face is smaller than the angle between the conical surface of the first diverter plate and the first end face, so as to blow a spiral airflow in an annular distribution into the main chamber through the plurality of first air outlet holes.

[0007] In some embodiments, the first diverter includes: a first disc body, which is conical and cylindrical, with its diameter gradually increasing along the direction from the secondary chamber to the main chamber, and the first disc body having a first end face with the largest diameter and a second end face with the smallest diameter along its axial direction; a second disc body, which is annular and cylindrical, and the second end face of the second disc body is connected to the second end face of the first disc body, and the outer peripheral wall of the second disc body is provided with a first air inlet that communicates with a plurality of first air outlets for introducing inert gas into the plurality of first air outlets through the first air inlet; wherein the diameter of the second disc body is equal to the diameter of the second end face.

[0008] In some embodiments, the first distribution plate further includes: a first annular pipe disposed in the second plate body, and a first air inlet communicating with the first annular pipe; and a plurality of air guide pipes disposed axially around the first plate body at intervals in the first plate body, one end of the plurality of air guide pipes being connected to a plurality of first air outlets in a corresponding manner, and the other end of the plurality of air guide pipes being connected to the first annular pipe through a first connecting pipe respectively.

[0009] In some embodiments, the conical surface of the first disc body has a first preset angle α between the first end face and the second end face, the first preset angle α satisfying: 59°≤a≤61°; and / or, the axial extension direction of the first vent hole has a second preset angle b between the first end face and the second end face, the second preset angle b satisfying: 28°≤b≤32°; and / or, the first vent hole has a first preset diameter D1, the first preset diameter D1 satisfying: 6mm≤D1≤10mm.

[0010] In some embodiments, at least a portion of the second distribution plate is a conical cylinder with a diameter that gradually decreases along the direction from the secondary chamber to the main chamber, and the second air outlet includes: a plurality of sets of second air outlet holes, which are spaced apart on the conical surface of the first distribution plate along the axial direction of the first distribution plate, and each set of second air outlet holes includes a plurality of second air outlet holes spaced apart around the axial direction of the first distribution plate.

[0011] In some embodiments, the second diverter includes: a third disc body, which is conical and cylindrical with a diameter that gradually decreases along the direction from the secondary chamber to the main chamber, the third disc body being located inside the secondary chamber, and a plurality of second air outlets being spaced apart on the conical surface of the third disc body; and a fourth disc body, which is annular and cylindrical and connected to the end face of the third disc body with the largest diameter along its axial direction, the fourth disc body having a second air inlet on one end face away from the third disc body that communicates with the plurality of second air outlets for introducing inert gas into the plurality of second air outlets through the second air inlet; wherein the diameter of the fourth disc body is equal to the maximum diameter of the third disc body.

[0012] In some embodiments, the second diverter plate further includes: a second annular pipe disposed in the fourth plate body, with a second air inlet communicating with the second annular pipe; and an air guide component, which is conical and disposed in the third plate body, with multiple sets of second air outlets communicating with the outer peripheral wall of the air guide component, and the air guide component being connected to the second annular pipe through multiple second connecting pipes.

[0013] In some embodiments, the conical surface of the second diverter disk has a third preset angle c with its end face along its axial direction, the third preset angle c satisfying: 59°≤a≤61°; and / or, the second air outlet has a second preset diameter D2, the second preset diameter D2 satisfying: 5mm≤D2≤7mm; and / or, there is a preset distance L between two adjacent second air outlets in a plurality of sets of second air outlets, the preset distance L satisfying: 7.95mm≤L≤8.05mm.

[0014] In some embodiments, the diameter of the second air outlet gradually decreases from the inner side to the outer side of the second distribution plate. The second air outlet includes a first hole segment and a second hole segment that are sequentially connected from the inner side to the outer side of the second distribution plate. Wherein, when the first hole segment is a circular hole, the second hole segment is a circular hole with a diameter smaller than that of the first hole segment or a conical hole with a maximum diameter the same as that of the first hole segment; or, when the first hole segment is a conical hole, the second hole segment is a circular hole with a diameter the same as that of the minimum diameter of the first hole segment or a conical hole with a maximum diameter the same as that of the minimum diameter of the first hole segment.

[0015] The technical solution provided in this application has at least the following advantages:

[0016] The first gas outlet on the first distribution plate creates a uniform annular airflow within the main chamber, effectively avoiding turbulence caused by gas backlash in traditional gas outlet structures. This reduces the impact of airflow on the crystal growth process, particularly preventing crystal wobble during ingot growth. Furthermore, the second gas outlet on the second distribution plate blows out inert gas distributed circumferentially, preventing the high-speed airflow and irregular vortices generated by the large argon flow at the furnace top inlet, which would cause the tungsten filament suspending the single crystal to sway. This ensures uniform distribution of inert gas within the secondary chamber, further optimizing the crystal growth environment and improving the stability and uniformity of crystal growth. This, in turn, solves at least the problem of crystal wobble in large-sized ingots caused by backlash in single-crystal furnaces in existing technologies. Moreover, the annular airflow from the first distribution plate enhances the entrainment and removal of oxides from the melt surface, reducing oxide adsorption on the melt surface during crystal growth, thereby improving the purity and quality of the ingot.

[0017] As can be seen, the design of the first and second gas outlets in this application provides flexibility in the direction and speed of gas flow. The gas flow rate and distribution can be adjusted according to the growth requirements of crystal rods of different sizes, ensuring the best gas control effect under various production conditions. Attached Figure Description

[0018] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the drawings in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this application or in the conventional art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a single crystal furnace provided in an embodiment of this application;

[0020] Figure 2 A schematic diagram of the structure of the first flow distribution plate of a single crystal furnace provided in an embodiment of this application from a first perspective;

[0021] Figure 3 for Figure 1 A cross-sectional view from the perspective of the middle AA (analogous to ...

[0022] Figure 4 A perspective view of a first distribution plate of a single crystal furnace provided in an embodiment of this application;

[0023] Figure 5 A schematic diagram of the structure of the first flow distribution plate of a single crystal furnace provided in an embodiment of this application, from a second perspective;

[0024] Figure 6 This is a schematic diagram of the structure of the second flow divider of a single crystal furnace provided in an embodiment of this application;

[0025] Figure 7 for Figure 5 A cross-sectional view from the perspective of the middle BB (Black-White) section;

[0026] Figure 8 A perspective view of the second distribution plate of a single crystal furnace provided in an embodiment of this application.

[0027] 1. Main room; 2. Secondary room;

[0028] 10. First distribution plate; 11. First air outlet; 110. First air outlet; 12. First plate body; 13. Second plate body; 14. First air inlet; 15. First annular pipe; 16. Air guide pipe; 17. First connecting pipe;

[0029] 20. Second distribution plate; 21. Second air outlet; 210. Second air outlet; 22. Third plate; 23. Fourth plate; 24. Second air inlet; 25. Second annular pipe; 26. Air guide component; 27. Second connecting pipe. Detailed Implementation

[0030] As the background technology indicates, Czochralski single crystal furnaces play a crucial role in the semiconductor and photovoltaic industries, used to produce high-quality single crystal silicon rods. Traditional single crystal furnaces are highly effective for manufacturing medium-sized rods, with oxygen content and other indicators meeting industry requirements. However, with the development trend of the single crystal silicon industry, the demand for large-sized rods is increasing. Traditional single crystal furnaces, when dealing with large rods, suffer from uneven gas coverage on the rod surface due to uneven argon flow rate and direction, further exacerbating crystal wobble problems. Furthermore, the entrainment efficiency of oxides and impurities is reduced, affecting the purity and performance of the rods.

[0031] This application provides a single crystal furnace.

[0032] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0033] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0034] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.

[0035] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0036] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0037] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0038] In the accompanying drawings corresponding to the embodiments of this application, the thickness and area of ​​the layers are enlarged for better understanding and ease of description. When describing a component (such as a layer, film, region, or substrate) on or on the surface of another component, the component may be "directly" located on the surface of the other component, or there may be a third component between the two components. Conversely, when describing a component on the surface of another component, or when another component is formed or disposed on the surface of a component, it indicates that there is no third component between the two components. Furthermore, when describing a component as being "generally" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a portion of the edge of the entire surface.

[0039] In the description of the embodiments of this application, when a component "includes" another component, other components are not excluded unless otherwise stated, and other components may be further included. Furthermore, when a component such as a layer, film, region, or plate is referred to as being "on / located" on another component, it can be "directly on" the other component (i.e., located on the surface of the other component with no other components between them), or another component may be present therein. Moreover, when a component such as a layer, film, region, or plate is "directly located" on another component, or when a component such as a layer, film, region, or plate is located on the surface of another component, it indicates that no other components are located therein.

[0040] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "part" is also intended to include the plural form unless the context clearly indicates otherwise. Components include layers, films, regions, or plates, etc.

[0041] The embodiments of this application will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0042] According to some embodiments of this application, such as Figures 1 to 8As shown, a single crystal furnace is provided, including a main chamber 1 and a secondary chamber 2; a first distribution plate 10 is disposed at the throat between the main chamber 1 and the secondary chamber 2, and a first gas outlet 11 is provided on the end face of the first distribution plate 10 away from the secondary chamber 2, the first gas outlet 11 is used to blow an inert gas flow in an annular distribution into the main chamber 1; a second distribution plate 20 is disposed at the end of the secondary chamber 2 away from the main chamber 1, at least a part of the second distribution plate 20 is located in the secondary chamber 2, and a second gas outlet 21 is provided on the outer peripheral wall of at least a part of the second distribution plate 20, the second gas outlet 21 is used to blow an inert gas flow in an circumferential distribution along the second distribution plate 20 into the secondary chamber 2.

[0043] The first gas outlet 11 on the first distribution plate 10 forms a uniform annular airflow within the main chamber 1, effectively avoiding turbulence caused by gas backlash in traditional gas outlet structures. This reduces the impact of airflow on the crystal growth process, especially preventing crystal wobble during ingot growth. Furthermore, the second gas outlet 21 on the second distribution plate 20 blows out inert gas distributed circumferentially, preventing the high-speed airflow and irregular vortices generated by the large argon flow rate at the traditional furnace top inlet, which would cause the tungsten wire suspending the single crystal to sway. This ensures uniform distribution of inert gas within the secondary chamber 2, further optimizing the crystal growth environment and improving the stability and uniformity of crystal growth. This at least solves the problem of large-size crystal wobble caused by backlash in single-crystal furnaces in existing technologies. Moreover, the annular airflow from the first distribution plate 10 enhances the entrainment and removal of oxides from the melt surface, reducing oxide adsorption on the melt surface during crystal growth, thereby improving the purity and quality of the crystal ingot.

[0044] As can be seen, the design of the first gas outlet 11 and the second gas outlet 21 in this application provides flexibility in the direction and speed of gas flow. The gas flow rate and distribution can be adjusted according to the growth requirements of crystal rods of different sizes, ensuring the best gas control effect under various production conditions.

[0045] In some embodiments, at least a portion of the first diverter plate 10 is a conical cylinder with a diameter that gradually increases along the direction from the secondary chamber 2 to the main chamber 1. At least a portion of the first diverter plate 10 has a first end face with the largest diameter along its axial direction. The first air outlet 11 includes a plurality of first air outlet holes 110, which are spaced apart around the axial direction of the first diverter plate 10 on the first end face. The angle between the axial extension direction of the first air outlet hole 110 and the first end face is smaller than the angle between the conical surface of the first diverter plate 10 and the first end face, so as to blow a spiral airflow in an annular distribution into the main chamber 1 through the plurality of first air outlet holes 110.

[0046] The conical structure of the first distribution plate 10 facilitates a smooth transition of gas at the throat, reducing gas flow resistance and improving gas distribution efficiency. The design of multiple first vent holes 110 guides the gas ejected from these holes to a spiral distribution along the inner wall of the main chamber 1, forming a spiral airflow. This ensures that the inert gas evenly covers the entire inner wall of the main chamber 1 and the surface of the crystal rod, reducing dead zones in gas coverage, ensuring a consistent crystal growth environment, and improving crystal rod quality. Furthermore, the special angle design of the first vent holes 110 ensures stable airflow distribution within the main chamber 1, avoiding turbulence caused by high-speed gas collisions, reducing crystal wobble during crystal rod growth, and improving crystal stability and yield. Moreover, compared to direct or annular airflow, spiral airflow has better entrainment and diffusion characteristics, more effectively removing oxides from the melt surface and improving the purity of crystal growth.

[0047] The above configuration allows the first distribution plate 10 to adapt to the production of crystal rods of different diameters. Even when adjusting the argon flow rate, it can maintain the uniformity and stability of gas distribution, enhancing the flexibility and adaptability of the equipment. Furthermore, the formation of the spiral airflow not only helps to achieve uniform gas distribution within the main chamber 1, but also improves the gas coverage and entrainment efficiency on the melt surface, reducing the enrichment of oxides and impurities. This plays a crucial role in improving the electronic purity and electrical properties of the crystal.

[0048] In some embodiments, such as Figures 2 to 5 As shown, the first diversion plate 10 includes: a first plate body 12, which is conical and cylindrical, and the diameter of the first plate body 12 gradually increases along the direction from the secondary chamber 2 to the main chamber 1. The first plate body 12 has a first end face with the largest diameter and a second end face with the smallest diameter along its axial direction; a second plate body 13, which is annular and cylindrical, and the second plate body 13 is connected to the second end face of the first plate body 12. The outer peripheral wall of the second plate body 13 is provided with a first air inlet 14 that communicates with a plurality of first air outlets 110, so as to introduce inert gas into the plurality of first air outlets 110 through the first air inlet 14; wherein, the diameter of the second plate body 13 is equal to the diameter of the second end face.

[0049] The conical cylindrical design of the first disk 12, with its gradually increasing diameter from the secondary chamber 2 to the main chamber 1, ensures a smooth transition of the inert gas before entering the main chamber 1, avoiding sudden accumulation or dispersion of the gas flow, thereby improving the uniform distribution of the gas within the main chamber 1. Multiple first vent holes 110 are provided on the first end face. Because the axial extension direction of the first vent holes 110 has a specific angle with the end face, this causes the gas to diffuse into the main chamber 1 in a spiral airflow manner, ensuring comprehensive and uniform gas coverage and avoiding crystal growth defects caused by excessively strong or weak local airflow.

[0050] The second disc 13, as an annular cylindrical structure, is connected to the second end face of the first disc 12, and their diameters remain consistent. This design helps maintain the stability and continuity of gas flow, avoiding turbulence or leakage at the connection point and improving the precision of gas control. The first air inlet 14 on the second disc 13 is connected to multiple first air outlets 110, forming a gas distribution system. This system can more precisely control the gas flow rate of each first air outlet 110, ensuring a consistent gas blowing effect at each outlet, thereby enhancing the overall stability and controllability of gas distribution.

[0051] By optimizing the gas flow path and distribution pattern, unnecessary gas consumption was reduced, lowering production costs. Simultaneously, a uniform and stable gas distribution helps increase crystal growth rate and shorten production cycles, thereby improving production efficiency and economic benefits.

[0052] In some embodiments, the first distribution plate 10 further includes: a first annular pipe 15 disposed within the second plate body 13, with a first air inlet 14 communicating with the first annular pipe 15; and a plurality of air guide pipes 16 disposed at intervals around the first plate body 12 axially within the first plate body 12, with one end of the plurality of air guide pipes 16 connected to a plurality of first air outlets 110 in a one-to-one correspondence, and the other end of the plurality of air guide pipes 16 respectively connected to the first annular pipe 15 through a first connecting pipe 17.

[0053] In this way, the first annular pipe 15 is connected to the first air inlet 14 on the second disc 13, forming a central node for gas distribution. Gas first enters the first annular pipe 15 through the first air inlet 14, and then is distributed to the corresponding first air outlet 110 via multiple air guide pipes 16. This design allows for more precise control of the gas flow rate at each first air outlet 110, ensuring uniform gas distribution within the main chamber 1. Multiple air guide pipes 16 are connected one-to-one with multiple first air outlets 110, and simultaneously connected to the first annular pipe 15 via a first connecting pipe 17. This structure ensures the stability and continuity of gas flow, avoids turbulence or leakage during gas distribution, and improves the efficiency and controllability of gas flow.

[0054] By combining the first annular pipe 15 and the gas guide pipe 16, the gas can be distributed more evenly to the first gas outlet 110, forming a spiral airflow that covers the inner wall of the main chamber 1 and the surface of the large-sized crystal rod. This reduces dead zones in gas coverage, improves the gas entrainment effect on the oxides on the melt surface, and helps to improve the purity and quality of crystal growth. Furthermore, this design allows for adjustments to the gas pressure or flow rate within the first annular pipe 15, as well as the distribution and opening size of the gas guide pipe 16, to meet the production needs of crystal rods of different sizes, providing high flexibility and adjustability in gas control.

[0055] In some embodiments, the conical surface of the first disk 12 has a first preset angle α between it and the first end face and the second end face, wherein the first preset angle α satisfies: 59°≤a≤61°. This first preset angle α design ensures the optimal angle between the conical surface of the first disk 12 and the gas flow direction. This angle design effectively reduces resistance during gas flow, allowing the gas to smoothly transition to the main chamber 1 at the throat, avoiding unnecessary turbulence, thereby optimizing gas flow efficiency.

[0056] In some embodiments, the axial extension direction of the first vent 110 has a second preset angle b between it and the first end face and the second end face, wherein the second preset angle b satisfies: 28°≤b≤32°. This design of the second preset angle b optimizes the angle between the axis of the first vent 110 and the first end face. This angle ensures that the gas ejected from the multiple first vents 110 is distributed spirally within the main chamber 1, resulting in wider coverage, more uniform airflow distribution, reduced dead zones in gas coverage, and crystal wobble during crystal growth, thereby improving crystal quality.

[0057] In some embodiments, the first vent 110 has a first preset diameter D1, which satisfies the following condition: 6mm ≤ D1 ≤ 10mm. This first preset diameter D1 is optimized for the size of the first vent 110. Within this size range, the first vent 110 ensures a sufficiently large gas flow rate while avoiding excessively high airflow velocity and turbulence due to an excessively small orifice diameter, or uneven gas distribution due to an excessively large orifice diameter. The design of the first vent 110 within this range, combined with its venting direction, helps improve the gas entrainment efficiency of oxides on the melt surface, reduces impurity adsorption, and enhances the purity and performance of the crystal.

[0058] In some embodiments, at least a portion of the second diversion disk 20 is a conical cylinder with a diameter that gradually decreases along the direction from the secondary chamber 2 to the main chamber 1. The second air outlet 21 includes a plurality of second air outlet holes 210, which are spaced apart on the conical surface of the first diversion disk 10 along the axial direction of the first diversion disk 10. Each set of second air outlet holes 210 includes a plurality of second air outlet holes 210 spaced apart around the axial direction of the first diversion disk 10.

[0059] The conical cylindrical structure of the second distribution disk 20 allows for a gradual transition from a large diameter on the side of the secondary chamber 2 to a small diameter on the side of the main chamber 1 during gas distribution within the secondary chamber 2. This design facilitates the gradual deceleration and smooth distribution of gas before it enters the main chamber 1, avoiding turbulence caused by sudden deceleration or accumulation, and achieving precise control of gas flow. Furthermore, the arrangement of multiple sets of second vent holes 210, each set including multiple second vent holes 210 spaced apart along the axial direction of the first distribution disk 10, ensures uniform gas distribution within the secondary chamber 2. This design avoids localized concentration of gas flow within the secondary chamber 2, reduces dead zones in gas coverage, promotes sufficient contact between the gas and the melt, and improves the uniformity and quality of crystal growth.

[0060] In some embodiments, such as Figures 6 to 8 As shown, the second diversion plate 20 includes: a third plate 22, which is conical and cylindrical, with its diameter gradually decreasing along the direction from the secondary chamber 2 to the main chamber 1. The third plate 22 is located inside the secondary chamber 2, and multiple sets of second air outlets 210 are spaced apart on the conical surface of the third plate 22; and a fourth plate 23, which is annular and cylindrical, and connected to the end face of the third plate 22 with the largest diameter along its axial direction. A second air inlet 24, which communicates with the multiple sets of second air outlets 210, is provided on the end face of the fourth plate 23 away from the third plate 22, for introducing inert gas into the multiple sets of second air outlets 210 through the second air inlet 24; wherein, the diameter of the fourth plate 23 is equal to the maximum diameter of the third plate 22.

[0061] In this way, the second air inlet 24 on the fourth disc 23 is connected to multiple sets of second air outlets 210 on the third disc 22, forming a gas distribution system from the secondary chamber 2 to the main chamber 1. This design ensures that the inert gas is precisely distributed to each second air outlet 210 at a precise flow rate and pressure, thereby forming a continuous and uniform gas coverage layer in the secondary chamber 2. This reduces turbulence in the secondary chamber 2 and the transition area between it and the main chamber 1, improving the accuracy and uniformity of gas distribution. The conical cylindrical structure of the third disc 22, combined with the annular cylindrical structure of the fourth disc 23, maintains the stability and continuity of the gas flow path. This design ensures that the gas entering from the second air inlet 24 can flow smoothly along the conical surface of the third disc 22 to the second air outlet 210, reducing gas flow resistance and leakage, and improving gas flow efficiency.

[0062] Multiple sets of second gas outlets 210 are spaced apart along the conical surface of the third disk 22, forming a continuous gas flow. This ensures a more uniform gas distribution within the sub-chamber 2, reducing the problem of localized gas excess or deficiency, and improving the uniformity and stability of crystal growth. It is evident that the second distribution disk 20, through the combined design of the third disk 22 and the fourth disk 23, enhances flexibility, adapting to changes in gas flow rate and pressure under different production conditions, including the production needs of large-size crystal rods. This ensures effective gas distribution during the transition from sub-chamber 2 to main chamber 1, improving the adaptability of the equipment and the flexibility of the production process.

[0063] In some embodiments, the second diverter plate 20 further includes: a second annular pipe 25 disposed within the fourth plate body 23, with a second air inlet 24 communicating with the second annular pipe 25; and an air guide component 26, which is conical and disposed within the third plate body 22, with multiple sets of second air outlets 210 communicating with the outer peripheral wall of the air guide component 26, and the air guide component 26 being connected to the second annular pipe 25 through multiple second connecting pipes 27.

[0064] The second annular pipe 25 serves as the central distribution point for the gas. It receives inert gas through the second inlet 24 and transports it to the gas guiding component 26 through multiple second connecting pipes 27. The gas guiding component 26 then evenly distributes the gas to multiple second outlets 210. This design effectively guides the gas to be evenly distributed to multiple sets of second outlets 210 and ensures that the gas flow rate from the second inlet 24 to the multiple sets of second outlets 210 is uniform and consistent. This avoids the imbalance of excessive or insufficient gas in certain areas, which is beneficial to improving the uniformity and stability of crystal growth.

[0065] By combining the gas guide component 26 with multiple sets of second gas outlets 210, the multiple sets of second gas outlets 210 can discharge gas in a direction symmetrical to the conical extension direction of the second distribution plate 20, and form an inert gas flow distributed circumferentially around the second distribution plate 20. This avoids the high-speed airflow and irregular vortex generated by the large argon flow rate at the traditional furnace top gas inlet, and thus solves the problem of crystal wobbling of large-size crystal rods caused by airflow back-blowing in the existing single crystal furnace.

[0066] In some embodiments, the conical surface of the second distribution disk 20 has a third preset angle c with its end face along its axial direction, wherein the third preset angle c satisfies: 59°≤a≤61°. The extending direction of the second air outlet 210 is perpendicular to the conical surface of the second distribution disk 20. This design of the third preset angle c ensures that when gas flows from the second annular pipe 25 through the gas guide component 26 to the multiple sets of second air outlets 210, the gas is circumferentially distributed and blown out into the sub-chamber 2 along a preset direction, avoiding the formation of turbulence. This angle selection makes the gas distribution in the sub-chamber 2 or in the transition region between the sub-chamber 2 and the main chamber 1 more uniform, reducing local concentration of airflow in the main chamber 1, which is beneficial to improving the uniformity and stability of crystal growth.

[0067] In some embodiments, the second vent 210 has a second preset diameter D2, which satisfies the following condition: 5mm ≤ D2 ≤ 7mm. This design of the second vent 210 with a second preset diameter D2 ensures that gas can be ejected from the second vent 210 at a suitable velocity under high argon flow conditions, avoiding turbulence caused by excessively small orifice diameter or uneven gas distribution caused by excessively large orifice diameter. Second vents 210 within this range help form a stable gas flow, preventing crystal wobble in large-sized crystal rods.

[0068] In some embodiments, a preset distance L is provided between adjacent second vent holes 210 in the plurality of sets of second vent holes 210, wherein the preset distance L satisfies: 7.95mm ≤ L ≤ 8.05mm. This preset distance L design ensures that the gas injection areas between the plurality of sets of second vent holes 210 do not overlap or create blank areas. This distance range ensures the continuity and uniformity of gas coverage, reduces gas coverage dead zones, and helps improve the uniformity and stability of crystal growth.

[0069] In some embodiments, the diameter of the second air outlet 210 gradually decreases from the inner side to the outer side of the second distribution plate 20. The second air outlet 210 includes a first hole segment and a second hole segment that are sequentially connected from the inner side to the outer side of the second distribution plate 20. Wherein, when the first hole segment is a circular hole, the second hole segment is a circular hole with a diameter smaller than that of the first hole segment or a conical hole with a maximum diameter the same as that of the first hole segment; or, when the first hole segment is a conical hole, the second hole segment is a circular hole with a diameter the same as that of the minimum diameter of the first hole segment or a conical hole with a maximum diameter the same as that of the minimum diameter of the first hole segment.

[0070] The aforementioned design, through the gradually decreasing aperture of the second vent 210, guides gas to flow more smoothly from the gas guide component 26 into the sub-chamber 2, reducing resistance and turbulence during gas flow and improving gas flow efficiency and stability. It also enhances the adaptability of the second distribution plate 20 to different argon flow rates. Under high argon flow conditions, the larger first orifice section ensures sufficient gas flow, while the gradually decreasing second orifice section facilitates smooth gas transition and distribution, ensuring effective gas distribution under various production conditions. Furthermore, the combined design of the first and second orifice sections helps maintain the structural stability and reliability of the second distribution plate 20, especially under high argon flow conditions, effectively controlling gas pressure and preventing equipment failures due to unstable gas flow, thus ensuring production continuity and stability. Simultaneously, it reduces unnecessary argon consumption, lowers production costs, and the uniform and stable gas distribution helps increase crystal growth rate and shorten the production cycle, thereby improving production efficiency.

[0071] In some embodiments, at least a portion of the first diversion disk 10 is conical, and a first carbon coating is provided on the inner wall of the first diversion disk 10. The first carbon coating has a first preset thickness h1, which satisfies the following: 45μm≤h1≤55μm.

[0072] In some embodiments, at least a portion of the second diversion disk 20 is conical, and a second carbon coating is provided on the inner wall of the second diversion disk 20. The second carbon coating has a second preset thickness h2, which satisfies the following condition: 45μm≤h2≤55μm.

[0073] The conical cylindrical first and second distribution disks 10 and 20 facilitate a smooth transition and uniform distribution of airflow. As the gas enters these conical cylindrical structures, it is gradually guided and evenly distributed to each outlet, reducing eddies and turbulence caused by sudden changes in airflow, thereby improving the uniformity and efficiency of gas distribution.

[0074] The preset thicknesses h1 and h2 of the first and second carbon coatings provide sufficient protection against erosion caused by high temperatures and gas scouring, while avoiding additional weight or obstruction of gas flow due to excessive coating thickness. This thickness range of carbon coatings ensures good protection while maintaining the lightweight and high efficiency of the equipment. Furthermore, the carbon coating on the inner wall reduces gas contamination in the secondary chamber 2 and throat area, preventing impurities caused by metal oxidation or corrosion from entering the melt, thus ensuring the purity and quality of the grown crystals.

[0075] In some embodiments, both the first distribution plate 10 and the second distribution plate 20 are made of stainless steel. This stainless steel material provides excellent corrosion resistance and wear resistance, enabling long-term operation under high temperatures and argon atmospheres, ensuring stable equipment operation and extending service life. Furthermore, stainless steel's good thermal conductivity contributes to uniform heat distribution, further optimizing the thermal environment for crystal growth and playing a positive role in improving crystal growth quality and consistency.

[0076] As can be seen, the combination of stainless steel material and a carbon coating of a predetermined thickness ensures the structural stability and manufacturing precision of the first and second distribution plates 10 and 20. This helps the equipment maintain good working condition under high argon flow conditions, reduces the risk of structural deformation, and ensures the long-term reliable operation of the equipment.

[0077] In some embodiments of this application, a preset total argon gas flow rate is used to introduce argon gas into the single crystal furnace; wherein, the first distribution plate 10 is used to introduce an argon gas flow rate of a first preset value, and the second distribution plate 20 is used to introduce an argon gas flow rate of a second preset value, the sum of the first preset value and the second preset value equals the preset total. For example, the preset total is 150 L / min, the first preset value is 50 L / min, and the second preset value is 100 L / min, which is expected to improve the minority carrier lifetime by 15% compared to the same batch of crystal rods. Furthermore, after adopting the first distribution plate 10 and the second distribution plate 20 of this application, the crystal wobbling rate is reduced from 45% to 5% compared to the existing argon gas outlet structure, and the oxygen content is reduced to 6-7 ppma.

[0078] In this application, after the single-crystal furnace uses a first shunt plate 10 and a second shunt plate 20 for shunt control, the oxygen content of the silicon wafer is reduced to 6-7 ppma. The oxygen content in the silicon wafer can be accurately measured by FTIR analysis. This method utilizes the infrared absorption characteristics of oxygen in silicon, calculating the oxygen content by measuring the intensity of the absorption peak. Alternatively, laser-induced fluorescence testing can be used, employing a laser to excite oxygen defects in the silicon wafer and measuring their fluorescence signal to determine the oxygen content, thus providing oxygen content data with high sensitivity and high spatial resolution.

[0079] According to some embodiments of this application, by controlling the flow distribution of the first and second flow distribution plates 10 and 20 in the single crystal furnace, the argon flow rate of the first preset value (e.g., 50 L / min) and the second preset value (e.g., 100 L / min) can be precisely adjusted to ensure the stability and accuracy of the total argon flow rate (preset total 150 L / min). This helps to avoid instability in crystal rod growth caused by airflow fluctuations, improving the uniformity and yield of crystal growth. Furthermore, the structural characteristics of the first and second flow distribution plates 10 and 20 can be fully utilized to precisely control the gas distribution in different regions of the single crystal furnace, avoiding the formation of high-speed eddies in localized areas, reducing the crystal rod wobble rate, and improving the stability of crystal growth.

[0080] Meanwhile, this flow control method allows the single crystal furnace to adapt not only to the growth requirements of ingots of different sizes, but also to flexibly handle different growth conditions and process parameters, improving the controllability and flexibility of the entire growth process. By precisely controlling the gas flow rate and optimizing the gas distribution, unnecessary gas consumption can be reduced, thus lowering production costs.

[0081] According to some embodiments of this application, a silicon wafer manufactured using the single-crystal furnace of this application has an oxygen content of 6-7 ppma. It is evident that the first and second flow dividers 10 within the single-crystal furnace significantly reduce the oxygen impurity content in the silicon wafer, not only significantly improving the purity and performance of the silicon wafer but also reducing production costs. Since oxygen impurities are one of the main factors affecting the quality and performance of silicon wafers, reducing their content helps improve the electrical and mechanical properties of the silicon wafer. Silicon wafers with low oxygen content can significantly improve minority carrier lifetime. Minority carrier lifetime is an important parameter measuring the carrier transport efficiency of semiconductor materials, directly affecting the photoelectric conversion efficiency and stability of photovoltaic cells and semiconductor devices. By optimizing the argon gas outlet structure design and improving the ability of argon gas to entrain oxides, oxygen impurities are reduced, indirectly improving the minority carrier lifetime of the silicon wafer.

[0082] Those skilled in the art will understand that the above embodiments are specific examples of implementing this application, and in practical applications, various changes in form and detail can be made without departing from the spirit and scope of this application. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this application; therefore, the scope of protection of this application should be determined by the scope defined in the claims.

Claims

1. A single crystal furnace, characterized in that, include: Main room (1) and secondary room (2); The first diversion plate (10) is located at the throat between the main chamber (1) and the auxiliary chamber (2). The first diversion plate (10) has a first air outlet (11) on the end face away from the auxiliary chamber (2). The first air outlet (11) is used to blow an inert gas flow in a ring shape into the main chamber (1). The second diversion plate (20) is disposed at one end of the sub-chamber (2) away from the main chamber (1). At least a portion of the second diversion plate (20) is located inside the sub-chamber (2), and a second air outlet (21) is provided on the outer peripheral wall of at least a portion of the second diversion plate (20). The second air outlet (21) is used to blow an inert gas flow that is distributed circumferentially along the second diversion plate (20) into the sub-chamber (2).

2. The single crystal furnace according to claim 1, characterized in that, At least a portion of the first diversion plate (10) is a conical cylinder with a diameter that gradually increases along the direction from the secondary chamber (2) to the main chamber (1). At least a portion of the first diversion plate (10) has a first end face with the largest diameter along its axial direction. The first air outlet (11) includes: Multiple first air outlets (110) are spaced apart on the first end face around the axial direction of the first distribution plate (10). The angle between the axial extension direction of the first air outlet (110) and the first end face is smaller than the angle between the conical surface of the first distribution plate (10) and the first end face, so as to blow out a spiral airflow in a ring shape into the main chamber (1) through the multiple first air outlets (110).

3. The single crystal furnace according to claim 2, characterized in that, The first distribution plate (10) includes: The first disc (12) is conical and cylindrical, and the diameter of the first disc (12) gradually increases along the direction from the sub-chamber (2) to the main chamber (1). The first disc (12) has a first end face with the largest diameter and a second end face with the smallest diameter along its axial direction. The second disc (13) is in the shape of an annular cylinder and is connected to the second end face of the first disc (12). The outer peripheral wall of the second disc (13) is provided with a first air inlet (14) that communicates with a plurality of first air outlets (110) for introducing the inert gas into the plurality of first air outlets (110) through the first air inlet (14). The diameter of the second disk (13) is equal to the diameter of the second end face.

4. The single crystal furnace according to claim 3, characterized in that, The first distribution plate (10) also includes: The first annular pipe (15) is disposed inside the second disc body (13), and the first air inlet (14) is connected to the first annular pipe (15); Multiple air guide pipes (16) are arranged axially around the first disc body (12) within the first disc body (12). One end of each of the multiple air guide pipes (16) is connected to a corresponding first air outlet (110), and the other end of each of the multiple air guide pipes (16) is connected to the first annular pipe (15) through a first connecting pipe (17).

5. The single crystal furnace according to claim 3, characterized in that, The conical surface of the first disc (12) has a first preset angle α between it and the first end face and the second end face, wherein the first preset angle α satisfies: 59°≤a≤61°; and / or, The axial extension direction of the first vent (110) forms a second preset angle b with respect to the first end face and the second end face, wherein the second preset angle b satisfies: 28° ≤ b ≤ 32°; and / or, The first vent (110) has a first preset diameter D1, which satisfies: 6mm≤D1≤10mm.

6. The single crystal furnace according to claim 1, characterized in that, At least a portion of the second diverter plate (20) is a conical cylinder with a diameter that gradually decreases along the direction from the secondary chamber (2) to the main chamber (1), and the second air outlet (21) includes: Multiple sets of second air outlets (210) are spaced apart on the conical surface of the first distribution plate (10) along the axial direction of the first distribution plate (10). Each set of second air outlets (210) includes multiple second air outlets (210) spaced apart around the axial direction of the first distribution plate (10).

7. The single crystal furnace according to claim 6, characterized in that, The second distribution plate (20) includes: The third disc (22) is conical and cylindrical, and the diameter of the third disc (22) gradually decreases along the direction from the sub-chamber (2) to the main chamber (1). The third disc (22) is located in the sub-chamber (2), and multiple sets of second air outlets (210) are spaced apart on the conical surface of the third disc (22). The fourth disc (23) is an annular cylindrical shape and is connected to the end face of the third disc (22) with the largest diameter along its axial direction. The end face of the fourth disc (23) away from the third disc (22) is provided with a second air inlet (24) that communicates with multiple sets of second air outlets (210) for introducing the inert gas into multiple sets of second air outlets (210) through the second air inlet (24). The diameter of the fourth disk (23) is equal to the maximum diameter of the third disk (22).

8. The single crystal furnace according to claim 7, characterized in that, The second distribution plate (20) also includes: The second annular pipe (25) is disposed inside the fourth disc (23), and the second air inlet (24) is connected to the second annular pipe (25); The air guide component (26) is in the shape of a cone and is disposed in the third disc (22). Multiple sets of second air outlets (210) are respectively connected to the outer peripheral wall of the air guide component (26). The air guide component (26) is connected to the second annular pipe (25) through multiple second connecting pipes (27).

9. The single crystal furnace according to claim 6, characterized in that, The conical surface of the second diverter (20) has a third preset angle c between it and its end face along its axial direction, the third preset angle c satisfying: 59°≤a≤61°; and / or, The second vent (210) has a second preset diameter D2, which satisfies: 5mm ≤ D2 ≤ 7mm; and / or, There is a preset distance L between two adjacent second air outlets (210) in the multiple sets of second air outlets (210), and the preset distance L satisfies: 7.95mm≤L≤8.05mm.

10. The single crystal furnace according to claim 6, characterized in that, The diameter of the second air outlet (210) gradually decreases from the inner side to the outer side of the second distribution plate (20). The second air outlet (210) includes a first hole section and a second hole section that are connected sequentially from the inner side to the outer side of the second distribution plate (20). Wherein, when the first hole segment is a circular hole, the second hole segment is a circular hole with a diameter smaller than that of the first hole segment or a conical hole with a maximum diameter the same as that of the first hole segment; or, when the first hole segment is a conical hole, the second hole segment is a circular hole with a diameter the same as that of the minimum diameter of the first hole segment or a conical hole with a maximum diameter the same as that of the minimum diameter of the first hole segment.

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