Feeding apparatus and single crystal furnace

Abstract

The present application provides a feeding apparatus and a single crystal furnace. The feeding apparatus comprises: a chamber body and a feed tube; one end of the feed tube is in communication with the chamber body; the other end of the feed tube is provided with a discharging section, and a minimum distance between the discharging section at a point distal to the chamber body and said chamber body is B, wherein 50 mm ≤ B ≤ 800 mm. Feedstock in a chamber body is fed to a single crystal furnace by means of a feed tube, so as to prevent the problem of the feedstock volatilizing during a feeding process due to a high-temperature environment of the single crystal furnace. This helps to improve resistivity uniformity of silicon rods, and improves silicon wafer quality.

Description

A feeding device and a single crystal furnace

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 2024117086361, filed on November 26, 2024, entitled "A Feeding Apparatus and a Single Crystal Furnace", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of crystal growth technology, specifically to a feeding device and a single crystal furnace. Background Technology

[0004] RCZ (Repeated Crystal Pulling) is a major method for preparing silicon rods. Its main characteristic is that raw materials are replenished to the crucible after each silicon rod is pulled, eliminating the need to wait for cooling, furnace shutdown, furnace disassembly, and furnace reassembly before adding materials again, resulting in high silicon rod pulling efficiency. During the rod pulling process, a certain amount of additives needs to be added to change the resistivity of the silicon rod.

[0005] In related technologies, additives are typically mixed with polycrystalline silicon raw materials first, so that the additives can be added to the crucible along with the polycrystalline silicon raw materials before high-temperature melting. During the high-temperature melting process, a large amount of additives may not enter the molten silicon due to volatilization, causing a significant deviation between the additive concentration in the molten silicon and the preset concentration. This makes it difficult to obtain silicon rods with good resistivity consistency, which is detrimental to obtaining high-quality silicon wafers. Summary of the Invention

[0006] This application aims to provide a feeding device and a single crystal furnace to solve the problem that existing feeding methods are not conducive to obtaining high-quality silicon wafers.

[0007] To solve the above-mentioned technical problems, this application is implemented as follows:

[0008] In a first aspect, this application discloses a feeding device, including: a bin body and a material pipe;

[0009] One end of the material pipe is connected to the silo body;

[0010] The other end of the material pipe is provided with a discharge section, and the minimum distance between the discharge section and the silo body is B, where 50mm≤B≤800mm.

[0011] The feeding device in this embodiment adds the additive from the chamber to the single crystal furnace through a feed pipe. This avoids the problem of additive volatilization during the high-temperature environment inside the single crystal furnace, which is beneficial to improving the resistivity consistency of the silicon rod and thus improving the quality of the silicon wafer. Furthermore, the minimum distance B between the discharge section of the feed pipe and the chamber is set to 50mm ≤ B ≤ 800mm. When the distance B is less than 50mm, the additive will come into contact with other components inside the single crystal furnace during the adding process, causing silicon sputtering when added to the molten silicon, affecting the crystal pulling efficiency. When the distance B is greater than 800mm, the high-temperature environment inside the crystal pulling channel causes the additive to melt before reaching the discharge section, resulting in a reduction in the amount of additive in the final silicon rod, which is detrimental to obtaining high-quality silicon wafers.

[0012] Optionally, the angle between the extension direction of the discharge section and the vertical direction is 10 degrees to 70 degrees, and / or the length of the discharge section is 30 mm to 50 mm.

[0013] By adopting the technical solution of this application, since the angle between the discharge section and the vertical direction is 10 degrees to 70 degrees, it prevents the added material from colliding with the hot zone components above the crucible in the single crystal furnace when the angle is less than 10 degrees, thus reducing the lifespan of the hot zone components. When the angle is greater than 70 degrees, the discharge section is closer to the crystal growth channel. Due to the high temperature in the single crystal furnace, the added material melts prematurely when it falls, making it impossible to add it to the molten silicon. This makes it impossible to guarantee the amount of added material in the final silicon wafer, making it difficult to obtain high-quality silicon wafers.

[0014] Optionally, the length of the discharge section ranges from 30 mm to 50 mm. Controlling the length of the discharge section within a suitable range allows the added material to be positioned within the conduit, ensuring that the final drop path of the added material output from the discharge section is controlled within a reasonable range. When the length of the discharge section is less than 30 mm, the drop position of the added material cannot be controlled due to its short time in the discharge section. When the length of the discharge section is greater than 50 mm, the discharge section is closer to the high-temperature environment inside the single crystal furnace, causing the added material to evaporate prematurely, making it impossible to obtain high-quality silicon wafers.

[0015] Optionally, the material pipe includes a guide pipe, the discharge section is located in the guide pipe, the guide pipe further includes a connecting section and a connecting segment connected in sequence, the connecting section is closer to the hopper than the connecting segment, the connecting segment is connected between the connecting segment and the discharge section, wherein the included angle between the connecting segment and the connecting segment is a second included angle, the included angle between the discharge section and the connecting segment is a third included angle, and the third included angle is greater than or equal to the second included angle.

[0016] The technical solution of this application includes a connecting section, a connecting section and a discharge section, which allows for flexible adjustment of the angle of the material guide tube, ensuring that the added material can flow out of the material guide tube more smoothly and enter the molten silicon from the discharge section along a preset path.

[0017] Optionally, the second or third included angle is between 110 and 150 degrees. This ensures that the added material experiences less stress at the connection points between the connecting section and the connecting segment, and between the connecting segment and the discharge section, effectively preventing the accumulation of the added material at the connection points and thus facilitating the smooth passage of the added material through the entire feed pipe.

[0018] Optionally, the feed pipe includes a guide pipe, the discharge section is located in the guide pipe, and the feed pipe also includes a feeding pipe connected between the silo and the guide pipe, the inner diameter of the feeding pipe being larger than the outer diameter of the guide pipe.

[0019] Using the technical solution of this application, after the material is added into the silo, it first enters the feeding pipe when passing through the material pipe, and finally flows out from the guide pipe. Since the inner diameter of the feeding pipe is larger than the outer diameter of the guide pipe, the material is added into the silo and first passes through the wider feeding pipe, allowing more material to be added from the feeding device, increasing the feeding amount. At the same time, the large inner diameter of the upper feeding pipe improves the feeding efficiency of the material. Finally, the material is added into the single crystal furnace through the guide pipe according to the predetermined trajectory, ensuring that the material is not volatilized in advance, thus improving the quality of the obtained silicon wafers.

[0020] Optionally, the feeding device further includes a feeding mechanism for adding additives into the hopper and / or the feed pipe. The feeding mechanism includes a material cup located in the hopper and / or the feed pipe, a drive member located at least partially outside the hopper and / or the feed pipe, and a rotating shaft connected between the drive member and the material cup. The drive member is connected to the rotating shaft to drive the rotating shaft to rotate the material cup, thereby pouring the additives in the material cup into the hopper and / or the feed pipe.

[0021] Because the feeding mechanism feeds material by rotating the material cup, it can precisely control the amount of material supplied in the cup, enabling real-time online supply of material and improving feeding efficiency and the stability of crystal pulling operation.

[0022] Optionally, the feeding device further includes: a feeding mechanism connected to the hopper and at least partially extending into the hopper, the feeding mechanism being used to convey the additive from the hopper to the material cup, the feeding mechanism including a push rod and a feeding channel, the feeding channel at least partially extending into the hopper; wherein, the push rod is movably connected within the feeding channel, the push rod being used to push the additive in the feeding channel into the material cup. The feeding mechanism adds the additive to the material cup through automated feeding, avoiding manual operation of adding the additive to the material cup, thereby improving feeding efficiency.

[0023] Secondly, this application also discloses a single crystal furnace, including a furnace body and a feeding device of any of the above; the feeding device is disposed in the furnace body, the hopper is at least partially located outside the furnace body, and the discharge section of the material pipe is located inside the furnace body.

[0024] Optionally, the furnace body includes a furnace body and a furnace cover disposed above the furnace body, the feeding device is connected to the furnace cover, and the vertical height between the discharge section and the uppermost edge of the furnace cover is 100mm to 400mm.

[0025] The technical solution of this application has a vertical height of 100mm to 400mm between the discharge section and the uppermost edge of the furnace cover. This means the discharge section extends at least partially above the hot zone components inside the single crystal furnace, allowing the additives to be introduced into the furnace and fall from above the hot zone components into the crucible. At this distance, the discharge section is relatively far from the crucible, minimizing the impact of the high-temperature environment near the crucible. This avoids the introduction of impurities and additive loss caused by premature melting or volatilization of the additives in the discharge section, further improving the control of the additive amount and facilitating the production of higher-quality silicon rods, thus resulting in higher-quality silicon wafers. Simultaneously, the discharge section does not contact the hot zone components or other structures inside the single crystal furnace, thus preventing any impact on the stability of crystal pulling.

[0026] It should be noted that in the embodiments of this application, the structure of the feeding device is the same as that of any of the feeding devices described above, and its beneficial effects are also similar, so it will not be described in detail here.

[0027] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 is a schematic diagram of the structure of a single crystal furnace using a feeding mechanism in one embodiment of the application;

[0030] Figure 2 is a partial structural schematic diagram of the single crystal furnace shown in Figure 1;

[0031] Figure 3 is an enlarged structural schematic diagram of position S of the single crystal furnace shown in Figure 1;

[0032] Figure 4 is a schematic diagram of the feeding device according to another embodiment of this application;

[0033] Figure 5 is a schematic diagram of the feeding device according to another embodiment of this application.

[0034] Reference numerals: 1-furnace body, 2-heater, 3-insulation cylinder, 4-crucible, 5-silicon liquid, 6-thermal field component, 61-crystal growth channel, 7-feeding device, 71-support, 72-isolation valve, 73-bin body, 730-inner cavity, 74-bin cover, 75-rotating shaft, 751-weighing sensor, 76-material tube seat, 77-material cup, 78-storage mechanism, 79-guide tube, 791-discharge section, 792-connecting section, 793-connecting section, 710-feeding channel, 711-feeding tube, 712-drive component, 713-feeding mechanism, 714-push rod, 715-feeding channel. Specific Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0036] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0037] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0038] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0039] This application provides a feeding device that can be used in a single crystal furnace. Specifically, the feeding device can be used to add additives to the crucible of the single crystal furnace. The additives can be materials other than silicon, such as dopants, impurity removers, etc. This application only uses dopants as an example for illustration; other types of additives can be described in the same way.

[0040] The feed pipe in this application can be a tubular structure used to connect to the hopper, allowing the added material inside the hopper to flow out to a predetermined position. For those skilled in the art, the feed pipe can be a guide pipe or a structure including both a guide pipe and a feed pipe. The guide pipe and the feed pipe can be integrated into a single structure or designed separately; those skilled in the art can choose according to their needs. In the embodiments of this application, a guide pipe is used as an example for illustration.

[0041] Referring to Figure 1, a schematic diagram of a single crystal furnace employing a feeding device according to an embodiment of the application is shown. Referring to Figure 2, a partial schematic diagram of the single crystal furnace shown in Figure 1 is shown. As shown in Figure 1, the single crystal furnace includes a furnace body 1, a crucible 4, and a heating element 6 located within the furnace body 1. The heating element 6 is located above the crucible 4. The crucible 4 and the heating element 6 can enclose and form a crystal growth channel 61. That is, a crystal growth channel 61 can be formed above the crucible 4. In practical applications, the crystal growth channel 61 can be used for the passage of single crystal silicon rods.

[0042] The feeding device of this application includes: a hopper body 73 and a material pipe; one end of the material pipe is connected to the hopper body 73; the other end of the material pipe has a discharge section 791, and the minimum distance between the discharge section 791 and the hopper body 73 at the distance away from the hopper body 73 is B, wherein 50mm≤B≤800mm.

[0043] In this embodiment of the application, the feed tube is described using a feed guide tube as an example. As shown in Figure 2, the feeding device 7 may specifically include: a chamber 73 with an inner cavity 730 and a feed guide tube 79; one end of the feed guide tube 79 is connected to the chamber 73; the other end of the feed guide tube 79 is provided with a discharge section 791, and the minimum distance between the discharge section 791 and the chamber 73 away from the chamber 73 is B, where 50mm≤B≤800mm, so as to guide the feed material into the furnace 1 and make the feed material fall from the crystal growth channel 61 into the crucible 4 without touching the heat exchanger and other components in the furnace 1, so as not to affect the stability of subsequent crystal pulling. When the distance B is less than 50mm, during the material addition operation, the material will come into contact with other components in the single crystal furnace during its fall, causing silicon sputtering when the material is added to the molten silicon, which affects the crystal pulling efficiency. When the distance B is greater than 800mm, the high temperature environment in the crystal pulling channel will cause the material to melt before reaching the discharge section, resulting in a reduction of the material added to the final silicon rod, which is not conducive to obtaining high-quality silicon wafers. At the same time, the distance between the material guide tube 79 and the chamber 73 is relatively far, which affects the material addition efficiency.

[0044] It should be noted that the minimum distance refers to the vertical distance between the discharge section 791 and the central axis of the silo body 73. It can be understood that when the discharge section 791 has a certain length, this distance refers to the vertical distance between the farthest point of the discharge section 791 away from the silo body and the central axis of the silo body.

[0045] For those skilled in the art, the feeding device has a discharge port on its hopper, which is the location where the added material flows out from the hopper 73. It can be rectangular or funnel-shaped, etc. The added material coming out of the discharge port is added into the guide pipe and then into the single crystal furnace through the guide pipe. This application does not limit the shape of the discharge port.

[0046] The feeding device in this embodiment may further include a feeding pipe 711 with a feeding channel 710 and a guide pipe 79; the feeding pipe 711 is connected to the outlet of the chamber 73, and the feeding channel 710 communicates with the inner cavity 730; one end of the guide pipe 79 is connected to the feeding channel 710. In this embodiment, the feeding device 7 can be used in a single crystal furnace. During the single crystal silicon rod pulling process in the single crystal furnace, the feeding device 7 can add additives to the furnace body 1 at appropriate times according to actual needs. In this way, the problem of easy volatilization of additives in the high-temperature environment inside the single crystal furnace can be avoided, which is conducive to obtaining silicon rods with resistivity matching the theoretical target design. Moreover, the operation of stopping the furnace to add additives can be avoided, which is conducive to improving the pulling efficiency of silicon rods. Furthermore, the minimum distance between the discharge section 791 and the chamber 73 is 50mm≤B≤800mm. The additive material coming out of the discharge section 791 can fall from the crystal growth channel 61 into the silicon solution in the crucible 4. Since the discharge section 791 is far from the crucible 4, it is less affected by the high temperature environment near the crucible 4. This avoids the problem of impurity introduction and additive loss caused by the premature melting or volatilization of the additive material in the discharge section 791, further improving the control of the additive concentration and quality, which is conducive to obtaining silicon rods of better quality.

[0047] In specific applications, the furnace body 1 serves as the main structural component of the single crystal furnace, and includes components such as a crucible 4, a heating element 6, a heater 2, and a heat-insulating cylinder 3. The crucible 4 can hold polycrystalline silicon raw materials; the heater 2 can be located on the side or bottom of the crucible 4, and is used to heat the polycrystalline silicon raw materials inside the crucible 4 to melt them into molten silicon 5; the heating element 6 can be located above the crucible 4, and is provided with a crystal growth channel 61 for the single crystal silicon rod to pass through, maintaining a suitable thermal environment for crystal pulling operations. For example, the heating element 6 can be, but is not limited to, a heat shield or a heat exchanger. This embodiment only uses a heat exchanger as an example; other types of heating elements 6 can be implemented similarly. The heat-insulating cylinder 3 can be fitted over the crucible 4 and the heating element 6, preventing heat loss.

[0048] In this embodiment, the feeding device 7 can be used in conjunction with a single crystal furnace. During the single crystal furnace's single crystal silicon rod pulling process, the feeding device 7 can add additives to the furnace body 1 at appropriate times as needed. For example, the feeding device 7 can be activated to add the additives to the crucible 4 after the polycrystalline silicon raw material in the crucible 4 has melted to a certain extent or completely melted.

[0049] In practical applications, the melting points of common additives such as indium, phosphorus, arsenic, antimony, and gallium are usually much lower than those of polycrystalline silicon raw materials (typically around 1420 degrees Celsius). Compared to traditional additive feeding methods, which involve adding the additives to the crucible 4 together with the polycrystalline silicon raw materials, leading to premature volatilization of the additives, the feeding method described in this embodiment allows for real-time addition of the additives. That is, during the pulling process of the silicon ingot, the additives can be added to the furnace body 1 at appropriate times according to actual needs using the feeding device 7, thus avoiding premature volatilization of the additives.

[0050] Furthermore, during the pulling process of the single-crystal silicon rod, the high-temperature region is near the heater 2 and the crucible 4. Since the minimum distance between the discharge section 791 at the end of the feeding device 79 and the chamber body is between 50mm and 800mm, the distance between the discharge section 791 and the high-temperature region near the crucible 4 is reasonably set, minimizing the impact of the high-temperature region. This avoids the premature melting of the additive within the discharge section 791, which could lead to blockage of the feeding pipe 79. In addition, since the additive, after being discharged from the discharge section 791, can fall into the crucible 4 along the crystal growth channel 61, i.e., the additive is added to the crucible 4 in solid form, rather than being preheated and vaporized before being added to the crucible 4 in gaseous form, this avoids the defect of not achieving the target doping concentration due to the gaseous additive being blown away by the inert gas in the furnace body 1, thus preventing the acquisition of silicon rods with good resistivity consistency and affecting the preparation of high-quality silicon wafers.

[0051] Referring to Figure 3, an enlarged structural schematic diagram of the single crystal furnace at position S shown in Figure 1 is displayed. As shown in Figure 3, a connecting section 792 is provided at one end of the material guide pipe 79 connected to the discharge section 791. The angle between the extension direction of the discharge section 791 and the vertical direction is 10 degrees to 70 degrees, so as to reasonably control the falling path of the additive particles output from the discharge section 791, so that the additive particles can fall from the crystal growth channel 61 of the hot zone component 6 to the crucible 4, and avoid the additive particles from colliding with the inside of the heat exchanger when falling.

[0052] It should be noted that the value of the first included angle r needs to be determined based on factors such as the size of the furnace body 1, the size and layout of the hot zone component 6, the distance between the discharge section 791 and the hot zone component 6, and the particle size of the additive, so as to control the additive particles to fall from the preset position of the crystal growth channel 61 of the hot zone component 6 and not volatilize prematurely.

[0053] For example, the value of the first included angle r can be 20 degrees, 30 degrees, 38 degrees, 45 degrees or 60 degrees, etc. This application embodiment does not specifically limit the value of the first included angle r.

[0054] As shown in Figure 2, the feed pipe 79 also includes a connecting section 792 and a connecting section 793 connected in sequence. The connecting section 792 is closer to the hopper 73 than the connecting section 793. The connecting section 793 connects the connecting section 792 and the discharge section 791. The included angle between the connecting section 793 and the connecting section 792 is the second included angle, and the included angle between the discharge section 791 and the connecting section 793 is the third included angle. The third included angle is greater than or equal to the second included angle.

[0055] In practical applications, after the additive enters the feed pipe 79 from the feed channel 710, it sequentially passes through the connecting section 792, the connecting section 793, and the discharge section 791, finally exiting from the discharge section 791 and falling into the crucible 4. As shown in Figure 2, the end of the connecting section 792 extending into the feed channel 710 is provided with a funnel-shaped opening to facilitate the smooth entry of the additive in the feed channel 710 into the connecting section 792. Since the third included angle β between the discharge section 791 and the connecting section 793 is greater than or equal to the second included angle α between the connecting section 793 and the connecting section 792, it is beneficial to set the extension path of the discharge section 791, making it easier for the discharge section 791 to extend above the crystal growth channel 61, so that the additive particles can fall from the crystal growth channel 61 into the crucible 4, avoiding collisions with the heat exchanger interior when the additive particles fall.

[0056] Optionally, both the second included angle α and the third included angle β are greater than 90 degrees, meaning both are obtuse angles. This results in lower stress levels at the connection points between the connecting section 792 and the connecting section 793, and between the connecting section 793 and the discharge section 791. This effectively prevents the accumulation of additives at these connection points, thus facilitating the smooth passage of the additives through the entire feed pipe 79.

[0057] Optionally, the second included angle α ranges from 110 degrees to 150 degrees, and the third included angle β ranges from 110 degrees to 150 degrees. This facilitates the smooth passage of the additive through the feed pipe 79 and allows for better control of the additive's drop path. This enables the additive to fall from the central region of the crystal growth channel 61 of the heat exchanger into the crucible 4, preventing the additive from impacting the interior of the heat exchanger and preventing premature evaporation.

[0058] It should be noted that the values ​​of the second included angle α and the third included angle β need to be determined based on factors such as the size of the furnace body 1, the size and layout of the hot zone component 6, the distance between the discharge section 791 and the hot zone component 6, and the particle size of the additive, so as to control the additive particles to fall from the center of the crystal growth channel 61 of the hot zone component 6 and not volatilize in advance as the ultimate control goal.

[0059] For example, the value of the second included angle α can be 110 degrees, 120 degrees, 125 degrees, 135 degrees or 150 degrees, etc., and the value of the third included angle β can be 110 degrees, 120 degrees, 125 degrees, 135 degrees or 150 degrees, etc., and the values ​​of the second included angle α and the third included angle β can be the same or different. In this embodiment of the application, the values ​​of the second included angle α and the third included angle β are not specifically limited.

[0060] Optionally, the feed pipe includes a guide pipe 79, a discharge section 791 located in the guide pipe 79, and a feeding pipe 711 connected between the hopper 73 and the guide pipe 79. The inner diameter of the feeding pipe 711 is larger than the outer diameter of the guide pipe 79.

[0061] By designing the feeding pipe and the guide pipe, the material being added enters the hopper, passes through the feed pipe, and finally flows out through the guide pipe. Because the inner diameter of the feeding pipe is larger than the outer diameter of the guide pipe, the material being added passes through the wider feeding pipe first, allowing more material to be added from the feeding device, thus increasing the feeding volume. At the same time, the larger inner diameter of the feeding pipe improves the feeding efficiency. Finally, the material is added into the single crystal furnace through the guide pipe along a predetermined trajectory, ensuring that the material does not evaporate prematurely and improving the quality of the obtained silicon wafers.

[0062] Optionally, a funnel structure is provided at one end of the feed pipe 79 away from the discharge section 791, and the feed pipe 79 is connected to the feed pipe 711 through the funnel structure.

[0063] Because of the large inner diameter of the feeding pipe, the funnel structure on the guide pipe can buffer the added material to a certain extent, preventing the added material that falls from the feeding pipe from not being added into the guide pipe.

[0064] As shown in Figure 3, the length h of the discharge section 791 ranges from 30 mm to 50 mm to control the length of the discharge section 791 within a suitable range. This ensures that the drop path of the added material output from the discharge section 791 is controlled within a reasonable range, while also allowing for better control of the distance between the discharge section 791, the hot zone component 6, and the single-crystal silicon rod, facilitating the layout of the guide pipe 79 within the furnace body 1.

[0065] It should be noted that the length h of the discharge section 791 can be determined based on factors such as the size of the furnace body 1, the size and layout of the hot zone component 6, and the particle size of the additive, so as to control the additive particles to fall from the center of the crystal growth channel 61 of the hot zone component 6 and not volatilize in advance as the ultimate control objective.

[0066] For example, the length h of the discharge section 791 may include, but is not limited to, 30 mm, 35 mm, 38 mm, 45 mm or 50 mm, etc. In this embodiment of the application, the length h of the discharge section 791 is not specifically limited.

[0067] As shown in Figure 2, the feeding device 7 may also include a support 71 and a feed pipe seat 76. The support 71 can be connected to the furnace body 1 to support the hopper 73. The feed pipe seat 76 can be connected to the bottom of the feeding channel 710 to support the guide pipe 79.

[0068] In practical applications, the furnace body 1 may include a furnace body and a furnace cover disposed on top of the furnace body. The support 71 of the feeding device 7 may be connected to the furnace body or the furnace cover. In practical applications, when the feeding device 7 needs to add the additive into the furnace body 1 from the side, the feeding device can be disposed on the side of the furnace body of the single crystal furnace. When the feeding device 7 needs to add the additive into the furnace body 1 from above, the support 71 may be connected to the furnace cover.

[0069] In some optional embodiments of this application, the feeding device 7 may further include: a feeding mechanism and a storage mechanism 78, both of which are disposed within the inner cavity 730. The feeding mechanism can be used to add material to the storage mechanism 78, and the storage mechanism 78 extends at least partially into the feeding channel 710 to guide the material into the feeding channel 710.

[0070] In some optional embodiments of this application, the feeding device further includes a pressure regulating mechanism, which is at least partially disposed within the inner cavity 730. This pressure regulating mechanism can be used to regulate the pressure within the inner cavity 730. By adjusting the pressure within the inner cavity 730 to match the pressure environment inside the furnace body 1, the feed material is then added to the furnace body 1. This avoids affecting the gas field environment inside the furnace body 1 during the feeding process, thereby improving the stability of the crystal pulling operation.

[0071] In practical applications, during the process of adding the feed material into the furnace body 1 using the feeding device 7, since the inner cavity 730 and the furnace body 1 are connected, if the air pressure conditions in the inner cavity 730 and the furnace body 1 are inconsistent, the airflow in the inner cavity 730 can easily rush into the furnace body 1, or the airflow in the furnace body 1 can easily overflow into the inner cavity 730. This will cause airflow turbulence within the furnace body 1, affecting the stability of the gas field environment within the furnace body 1.

[0072] In this embodiment, a pressure regulating mechanism can be provided in the feeding device 7, and the pressure regulating mechanism is located at least partially in the inner cavity 730. Before the feeding device 7 is started to add the material, the pressure regulating structure can be used to adjust the pressure in the inner cavity 730 to be consistent with the pressure in the furnace body 1. In this way, the phenomenon of airflow turbulence in the furnace body 1 during the feeding process can be avoided.

[0073] Optionally, the air pressure regulating mechanism may include an air inlet and an air outlet disposed in the inner cavity 730, and an isolation valve 72 disposed in the feeding channel 710 (as shown in Figure 2). The isolation valve 72 can be used to control the air flow between the inner cavity 730 and the furnace body 1. When the air pressure in the inner cavity 730 is the same as the air pressure in the furnace body 1, the isolation valve 72 is opened.

[0074] For those skilled in the art, an isolation valve can be a slide gate valve, a ball valve, or other valve that controls the flow of air. In this application, a ball valve is used as the isolation valve because it is economical and simple in structure. Those skilled in the art can choose the type of isolation valve according to the specific circumstances, and this application does not limit this choice.

[0075] Specifically, the pressure regulating mechanism can detect the pressure value of the inner cavity 730 in real time. The air inlet can be used to introduce gas into the inner cavity 730, and the air outlet can be used to discharge the gas from the inner cavity 730 to the outside. By controlling the operation of introducing gas into the air inlet or discharging gas from the air outlet, the air pressure in the inner cavity 730 can be regulated. In practical applications, when no additives are needed, the isolation valve 72 can be closed to isolate the inner cavity 730 from the furnace body 1. When additives are needed, the pressure value inside the inner cavity 730 can be obtained through a pressure gauge and compared with the pressure value inside the furnace. If the pressure value inside the cavity is lower than the pressure value inside the furnace, the air inlet is controlled to introduce gas into the inner cavity 730; if the pressure value inside the cavity is higher than the pressure value inside the furnace, the air outlet is controlled to discharge part of the gas from the inner cavity 730 until the pressure value inside the cavity matches the pressure value inside the furnace. Then, the isolation valve 72 is opened to connect the inner cavity 730 with the furnace body 1, so as to facilitate the addition of the dopant into the furnace body 1.

[0076] Referring to Figure 4, a schematic diagram of another feeding device according to an embodiment of this application is shown. As shown in Figure 4, the feeding device 7 does not have a pressure regulating structure. Accordingly, there is no need to install an isolation valve 72 in the feeding channel 710 of the feeding pipe 711. This makes the structure of the feeding pipe 711 simpler, which is beneficial for simplifying the overall structure of the feeding device 7 and for facilitating the layout of the feeding device 7 on the single crystal furnace.

[0077] In some optional embodiments of this application, the feeding device further includes a feeding mechanism for adding additives into the chamber 73 and / or the guide tube 79. The feeding mechanism includes a material cup 77 located in the chamber 73 and / or the guide tube, a drive member 712 located at least partially outside the chamber 73 and / or the guide tube 79, and a rotating shaft 75 connected between the drive member 712 and the material cup 77. The drive member 712 is connected to the rotating shaft 75 to drive the rotating shaft 75 to rotate the material cup 77, thereby pouring the additives in the material cup 77 into the chamber 73 and / or the guide tube 79. Since the feeding mechanism is connected to the rotating shaft through the drive member, and drives the material cup to rotate to achieve feeding, the supply amount of additives in the material cup can be precisely controlled, realizing real-time online supply of additives, improving feeding efficiency and the stability of crystal pulling operation.

[0078] As shown in Figure 2, the feeding mechanism may specifically include: a material cup 77, a rotating shaft 75, and a driving component 712; wherein, the material cup 77 is connected to the rotating shaft 75, and the rotating shaft 75 is rotatably connected to the inner cavity 730; the driving component 712 is connected to the rotating shaft 75 to drive the rotating shaft 75 to rotate the material cup 77, so as to pour the added material in the material cup 77 into the storage mechanism 78.

[0079] In practical applications, the weighed additive can be placed into the material cup 77, and then the drive unit 712 is activated to drive the rotating shaft 75 to rotate the material cup 77, so as to pour the additive in the material cup 77 into the storage mechanism 78.

[0080] As shown in Figure 2, the feeding device 7 may also include a bin cover 74, which is detachably connected to the top of the bin body 73 and forms an inner cavity 730 with the bin body 73. Normally, during manual feeding, after weighing the material to be added, the bin cover 74 can be removed, the material can be added into the material cup 77, and then the bin cover 74 can be placed back on the bin body 73.

[0081] As shown in Figure 2, the material storage mechanism 78 may specifically include a funnel, which is disposed opposite to the material cup 77 to facilitate the introduction of the additive in the material cup 77 into the funnel. In practical applications, the end of the funnel near the material cup 77 may be provided with a funnel-shaped opening to catch the additive falling from the material cup 77 and prevent the additive from falling into an area outside the funnel.

[0082] Referring to FIG5, a structural schematic diagram of another feeding device according to an embodiment of the present application is shown. As shown in FIG5, the feeding device 7 may further include: a feeding mechanism 713, which is connected to the hopper 73 and extends at least partially into the inner cavity 730. The feeding mechanism 713 can be used to transport the additive from outside the inner cavity 730 to the material cup 77, so as to add the additive to the material cup 77 in an automated feeding manner, avoiding the operation of adding the additive to the material cup 77 by manual operation, thereby improving the feeding efficiency.

[0083] Optionally, the feeding mechanism 713 is connected to the hopper 73 and extends at least partially into the hopper 73. The feeding mechanism 713 is used to convey the added material from the hopper 73 to the material cup 77. The feeding mechanism 713 includes a push rod 714 and a feeding channel 715, which extends at least partially into the hopper 73. The push rod 714 is movably connected within the feeding channel 715 and is used to push the added material in the feeding channel 715 into the material cup 77.

[0084] In practical applications, as shown in Figure 5, a weighing sensor 751 can also be installed on the rotating shaft 75. The weighing sensor 751 can be used to weigh the added material. Specifically, the added material can be added to the feeding channel 715, and then the push rod 714 is used to push the added material to move within the feeding channel 715 until the added material falls into the material cup 77. The weighing sensor 751 can be used to weigh the added material in the material cup 77. After the added material in the material cup 77 reaches the preset target weight, the rotating shaft 75 can drive the material cup 77 to rotate, pouring the added material in the material cup 77 into the storage mechanism 78.

[0085] In some alternative embodiments of this application, the material cup 77, the material storage mechanism 78, the material feeding tube 711, and the material guiding tube 79 are all made of quartz. Since the material cup 77, the material storage mechanism 78, the material feeding tube 711, and the material guiding tube 79 all need to be in direct contact with the added material, and since the above components are all made of stable quartz, it is not easy to introduce new impurities during the addition of the added material, which is beneficial to the quality control of the single crystal silicon rod.

[0086] It should be noted that the materials of the material cup 77, the material storage mechanism 78, the material feeding tube 711, and the material guide tube 79 can also be other materials that are not easily reacted with the added materials. This application embodiment does not limit this.

[0087] In summary, the feeding device described in the embodiments of this application may include at least the following advantages:

[0088] In this embodiment, the feeding device can be used in a single-crystal furnace. During the single-crystal silicon rod pulling process in the single-crystal furnace, the feeding device can add additives to the furnace body at appropriate times according to actual needs. This avoids the problem of additives easily volatilizing due to being added to the crucible and melting at high temperatures along with the polycrystalline silicon raw material, which is beneficial for obtaining silicon rods with resistivity matching the theoretical target design. Moreover, it avoids the operation of stopping the furnace to add additives, which is beneficial for improving the pulling efficiency of silicon rods. In addition, since the discharge section of the guide tube is inclined downward relative to the vertical direction and extends at least partially above the crystal growth channel, the additives coming out of the discharge section can fall from the crystal growth channel of the hot zone component into the crucible. Since the distance between the discharge section and the crucible is relatively far, it is less affected by the high-temperature environment near the crucible, which can also avoid the problem of impurity introduction and additive loss caused by premature melting or volatilization of the additives in the discharge section, further improving the control of additive concentration and quality, which is beneficial for obtaining silicon rods of higher quality.

[0089] This application embodiment also provides a single crystal furnace as shown in FIG1. ​​As shown in FIG1, the single crystal furnace includes: furnace body 1 and feeding device 7 as described in any of the above embodiments; the feeding device 7 is disposed in the furnace body 1, the hopper 73 is at least partially located outside the furnace body 1, and the discharge section 791 of the material pipe is located inside the furnace body 1.

[0090] It should be noted that in this embodiment, the structure of the feeding device 7 is the same as that of the feeding device 7 described in any of the above embodiments, and its beneficial effects are similar, so it will not be described in detail here.

[0091] As shown in Figure 1, the single crystal furnace may further include a heater 2 and a crucible 4; wherein, the crucible 4 and the heater 2 are both located inside the furnace body 1, the thermal field component 6 is located above the crucible 4, and a crystal growth channel 61 is formed above the crucible 4; the feeding device 7 is connected to the furnace body 1, and the discharge section 791 of the feeding device 7's guide pipe 79 extends at least partially above the crystal growth channel 61 to introduce the additive into the furnace body 1 and allow the additive to fall from the crystal growth channel 61 into the crucible 4.

[0092] During the single-crystal silicon rod pulling process in the single-crystal furnace, the feeding device 7 can add additives to the furnace body 1 at appropriate times according to actual needs. This avoids the problem of additives easily volatilizing when added to the crucible 4 together with the polycrystalline silicon raw material, which is beneficial for obtaining silicon rods with resistivity matching the theoretical target design. Moreover, it avoids the operation of stopping the furnace to add additives, which is beneficial for improving the pulling efficiency of silicon rods. In addition, since the discharge section 791 of the guide tube 79 is inclined downward relative to the vertical direction and extends at least partially above the crystal growth channel 61, the additives coming out of the discharge section 791 can fall from the crystal growth channel 61 of the hot zone component 6 into the crucible 4. Since the distance between the discharge section 791 and the crucible 4 is relatively far, it is less affected by the high temperature environment near the crucible 4. This also avoids the problem of impurity introduction and additive loss caused by premature melting or volatilization of the additives in the discharge section 791, further improving the control of additive concentration and quality, which is beneficial for obtaining silicon rods of higher quality.

[0093] Optionally, the furnace body 1 includes a furnace body and a furnace cover disposed above the furnace body, the feeding device 7 is connected to the furnace cover, and the vertical height between the discharge section 791 and the uppermost edge of the furnace cover is 100mm to 400mm.

[0094] The vertical height between the discharge section 791 and the uppermost edge of the furnace cover is 100mm to 400mm. This means the discharge section extends at least partially above the thermal zone component 6 inside the single crystal furnace. This allows the additive to be guided into the furnace and fall from above the thermal zone component 6 into the crucible 4. The distance between the discharge section 791 and the crucible 4 is relatively large, minimizing the impact of the high-temperature environment near the crucible 4. This avoids the introduction of impurities and additive loss caused by premature melting or volatilization of the additive in the discharge section 791, further improving the control of the additive amount. This is beneficial for obtaining higher-quality silicon rods, resulting in higher-quality silicon wafers. Simultaneously, the discharge section will not touch the thermal zone components or other structures inside the single crystal furnace, thus avoiding impact on the stability of crystal pulling.

[0095] It should be further explained that the shape of the furnace cover of a single crystal furnace is usually circular or elliptical. The uppermost edge of the furnace cover can be understood as the furthest point on the horizontal plane from the bottom of the furnace body. This furthest point can be the vertex of the circular or elliptical structure. Therefore, the vertical height between the discharge section and the upper edge of the furnace cover refers to the vertical distance between the lowermost edge of the discharge section and the uppermost edge of the furnace cover.

[0096] In practical applications, when the feeding device 7 needs to add the additive into the furnace body 1 from the side, the support 71 of the feeding device 7 can be connected to the furnace body or the furnace cover. When the feeding device 7 needs to add the additive into the furnace body 1 from above, the support 71 of the feeding device 7 can be connected to the furnace cover. This application embodiment does not specifically limit the connection position of the feeding device 7 on the furnace body 1.

[0097] In some optional embodiments of this application, the distance A between the side of the discharge section 791 closest to the center of the furnace body 1 and the centerline of the furnace body 1 satisfies 150mm≤A≤500mm. In specific applications, when the distance A is less than 150mm, the feeding efficiency of the material is affected because the distance between the guide pipe 79 and the bin 73 is relatively large; when the distance A is greater than 500mm, the material will come into contact with components such as the heat exchanger inside the furnace body 1 during the material feeding operation, affecting the crystal pulling stability of the single crystal furnace.

[0098] In some alternative embodiments of this application, the distance C between the central axis of the feeding device 7 and the side wall of the furnace body 1 satisfies 50mm≤C≤800mm. This distance control between the feeding device 7 and the side wall of the furnace body balances feeding efficiency and crystal pulling stability. In specific applications, when the distance C is less than 50mm, the feeding efficiency is affected because the distance between the feeding device 7 and the crystal growth channel 61 is too far. When the distance C is greater than 800mm, during the feeding operation, the feeding device 7 is too close to the crystal growth channel 61, and the added material falling from the feeding device 7 will come into contact with components such as the heat exchanger inside the furnace body 1, affecting the crystal pulling stability of the single crystal furnace.

[0099] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0100] The terms "an embodiment," "embodiment," or "one or more embodiments" as used herein mean that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of this application. Furthermore, please note that the examples of the phrase "in one embodiment" do not necessarily all refer to the same embodiment.

[0101] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of this application may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0102] In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. This application can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A feeding device (7), wherein, The feeding device (7) includes: a bin body (73) and a material pipe; One end of the material pipe is connected to the hopper body (73); The other end of the material pipe has a discharge section (791), and the minimum distance between the discharge section (791) and the silo (73) away from the silo (73) is B, where 50mm≤B≤800mm.

2. The feeding device (7) according to claim 1, wherein, The angle between the extension direction of the discharge section (791) and the vertical direction is 10 degrees to 70 degrees, and / or the length of the discharge section (791) is 30 mm to 50 mm.

3. The feeding device (7) according to claim 1, wherein, The material pipe includes a guide pipe (79), and the discharge section (791) is located in the guide pipe (79). The guide pipe (79) also includes a connecting section (792) and a connecting section (793) connected in sequence. The connecting section (792) is closer to the hopper (73) than the connecting section (793). The connecting section (793) is connected between the connecting section (792) and the discharge section (791). The included angle between the connecting section (793) and the connecting section (792) is a second included angle, and the included angle between the discharge section (791) and the connecting section (793) is a third included angle. The third included angle is greater than or equal to the second included angle.

4. The feeding device according to claim 3, wherein, Both the second included angle and the third included angle are greater than 90 degrees.

5. The feeding device (7) according to claim 3, wherein, The second included angle or the third included angle is between 110 degrees and 150 degrees.

6. The feeding device (7) according to claim 1, wherein, The material pipe includes a guide pipe (79), the discharge section (791) is located in the guide pipe (79), and the material pipe also includes a feeding pipe (711), which is connected between the silo body (73) and the guide pipe (79). The inner diameter of the feeding pipe (711) is larger than the outer diameter of the guide pipe (79).

7. The feeding device (7) according to claim 6, wherein, A funnel structure is provided at one end of the guide pipe (79) away from the discharge section (791), and the guide pipe (79) is connected to the feeding pipe (711) through the funnel structure.

8. The feeding device (7) according to claim 1, wherein, The feeding device (7) further includes a feeding mechanism for adding material into the hopper (73) and / or the feed tube. The feeding mechanism includes a material cup (77) located in the hopper (73) and / or the feed tube, a drive member (712) located at least partially outside the hopper (73) and / or the feed tube, and a rotating shaft (75) connected between the drive member (712) and the material cup (77). The drive member (712) is connected to the rotating shaft (75) to drive the rotating shaft (75) to rotate the material cup (77) so as to pour the material in the material cup (77) into the hopper (73) and / or the feed tube.

9. The feeding device (7) according to claim 8, wherein, The feeding device (7) further includes a feeding mechanism (713), which is connected to the hopper (73) and extends at least partially into the hopper (73). The feeding mechanism (713) is used to convey the additive from the hopper (73) to the material cup (77). The feeding mechanism (713) includes a push rod (714) and a feeding channel (715), which extends at least partially into the hopper (73). The push rod (714) is movably connected within the feed channel (715) and is used to push the additive in the feed channel (715) into the material cup (77).

10. The feeding device (7) according to claim 8, wherein, The feeding device further includes a storage mechanism (78), which is located between the feeding mechanism and the material tube. The storage mechanism (78) includes a funnel, which is arranged opposite to the material cup (77).

11. A single crystal furnace, wherein, The single crystal furnace includes: a furnace body (1) and a feeding device (7) as described in any one of claims 1 to 10; The feeding device (7) is located in the furnace body (1), the hopper (73) is at least partially located outside the furnace body (1), and the discharge section (791) of the material pipe is located inside the furnace body (1).

12. The single crystal furnace according to claim 11, wherein, The distance between the side of the discharge section (791) closest to the center of the furnace body and the center line of the furnace body is 150mm≤A≤500mm, and / or the distance between the central axis of the silo (73) and the side wall of the furnace body is 50mm≤C≤800mm.

13. The single crystal furnace according to claim 11, wherein, The single crystal furnace also includes a gas pressure regulating mechanism, which includes an isolation valve (72) disposed on the feed pipe. The isolation valve (72) is used to isolate or connect the chamber (73) and the furnace body (1).

14. The single crystal furnace according to claim 11, wherein, The furnace body (1) includes a furnace body and a furnace cover disposed above the furnace body. The feeding device (7) is connected to the furnace cover. The vertical height between the discharge section (791) and the uppermost edge of the furnace cover is 100mm to 400mm.

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