Feeding device and single crystal furnace

Abstract

The invention provides a feeding device and a single crystal furnace. The feeding device comprises a bin body and a material pipe, one end of the material pipe is communicated with the bin body; the other end of the material pipe is provided with a discharging section, the minimum distance between the position, away from the bin body, of the discharging section and the bin body is B, and B is larger than or equal to 50 mm and smaller than or equal to 800 mm. The addition material in the bin body is added into the single crystal furnace through the material pipe, so that the problem of volatilization of the addition material in a high-temperature environment in the single crystal furnace can be avoided, the resistivity consistency of a silicon rod is favorably improved, and the quality of a silicon wafer is improved.

Description

Technical Field

[0001] The present application belongs to the technical field of crystal growth, and in particular relates to a feeding device and a single crystal furnace. Background Art

[0002] RCZ (repeated crystal pulling) is a major method for preparing silicon rods. Its main feature is that raw materials are added to the crucible after each silicon rod is pulled. There is no need to wait for cooling, stopping, dismantling, or reloading the furnace before adding raw materials. It has a high silicon rod pulling efficiency. During the process of pulling the crystal rod, a certain amount of additives needs to be added to change the resistivity of the silicon rod.

[0003] In the existing technology, the additive is usually mixed with the polysilicon raw material first, so that the additive can be added to the crucible together with the polysilicon raw material, and then the high-temperature melting is carried out. During the high-temperature melting process, a large amount of additives may not enter the molten silicon due to volatilization, resulting in a serious deviation between the concentration of the additive in the molten silicon and the preset concentration, making it difficult to obtain silicon rods with good resistivity consistency, which is not conducive to obtaining high-quality silicon wafers. Summary of the invention

[0004] The present application aims to provide a feeding device and a single crystal furnace to solve the problem that the existing method of adding additives is not conducive to obtaining high-quality silicon wafers.

[0005] In order to solve the above technical problems, this application is implemented as follows:

[0006] In a first aspect, the present application discloses a feeding device, comprising: a bin body, a feeding pipe;

[0007] One end of the material pipe is connected to the bin body;

[0008] The other end of the material pipe is provided with a discharging section, and the minimum distance between the discharging section and the silo body is B, where 50mm≤B≤800mm.

[0009] The feeding device of the embodiment of the present application adds the additives in the bin to the single crystal furnace through the material pipe, which can avoid the problem of volatilization of the additives during the addition process under the high temperature environment in the single crystal furnace, which is beneficial to improving the resistivity consistency of the silicon rod and improving the quality of the silicon wafer. In addition, the minimum distance B between the discharge section on the material pipe and the bin body is set to 50mm≤B≤800mm. When the distance B is less than 50mm, when the operation of adding materials is performed, the additives will touch other components in the single crystal furnace during the falling process, and cannot be fully added to the molten silicon in the crucible, affecting the preparation of high-quality silicon wafers; when the distance B is greater than 800mm, the high temperature environment in the crystal pulling channel will cause the additives to be melted before reaching the discharge section, resulting in a reduction in the added materials in the final silicon rod, which is not conducive to obtaining high-quality silicon wafers.

[0010] 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.

[0011] By adopting the technical solution of the present application, since the angle between the discharge section and the vertical direction is 10 degrees to 70 degrees, when the angle is less than 10 degrees, the added material will collide with the thermal field components above the crucible in the single crystal furnace when falling, thereby reducing the life of the thermal field components, and the time for the added material to fall from the crystal growth channel to the molten silicon in the single crystal furnace is difficult to control, resulting in premature melting of the added material and affecting the quality of the silicon wafer; when the angle is greater than 70 degrees, the discharge section is closer to the crystal growth channel, and the high temperature in the single crystal furnace causes the added material to melt prematurely when falling, resulting in the inability to be added to the molten silicon, and the amount of added material in the final silicon wafer cannot be guaranteed, making it difficult to obtain high-quality silicon wafers.

[0012] Optionally, the length of the discharging section ranges from 30 mm to 50 mm. The length of the discharging section is controlled within an appropriate range so that the position of the added material can be adjusted in the conduit, ensuring that the falling path of the added material finally output from the discharging section is controlled within a reasonable range. When the length of the discharging section is less than 30 mm, the position of the added material falling cannot be controlled due to the short time the added material spends in the discharging section; when the length of the discharging section is greater than 50 mm, the discharging section is closer to the high temperature environment in the single crystal furnace, causing the added material to volatilize prematurely, and high-quality silicon wafers cannot be prepared.

[0013] Optionally, the material pipe includes a material guide pipe, the discharge section is located in the material guide pipe, the material guide pipe also includes a connecting section and a connecting section connected in sequence, the connecting section is closer to the warehouse body than the connecting section, and the connecting section is connected between the connecting section and the discharge section, wherein the angle between the connecting section and the connecting section is the second angle, the angle between the discharge section and the connecting section is a third angle, and the third angle is greater than or equal to the second angle.

[0014] By adopting the technical solution of the present application, the material guide pipe includes a connecting section, a connecting section and a discharge section, so that the angle of the material guide pipe can be flexibly adjusted to ensure that the added material can flow out of the material guide pipe more smoothly and enter the molten silicon from the discharge section along a preset path.

[0015] Optionally, the second angle or the third angle is in a range of 110 to 150 degrees, so that the stress on the additive when passing through the connection between the connecting section and the connecting section, and the connection between the connecting section and the material discharging section is small, and the accumulation of the additive at the connection can be effectively avoided, thereby facilitating the additive to pass smoothly through the entire material guiding pipe.

[0016] Optionally, the material pipe includes a material guide pipe, the material discharge section is located in the material guide pipe, and the material pipe also includes a feeding pipe, the feeding pipe is connected between the bin body and the material guide pipe, and the inner diameter of the feeding pipe is greater than the outer diameter of the material guide pipe.

[0017] By adopting the technical solution of the present application, after the added material enters the warehouse body, it first enters the feeding pipe when passing through the material pipe, and finally flows out from the material guide pipe. Since the inner diameter of the feeding pipe is larger than the outer diameter of the material guide pipe, after the added material is added to the warehouse body, it first passes through the feeding pipe with a wider path, so that more added material is added from the feeding device, increasing the feeding amount. At the same time, the inner diameter of the feeding pipe above is set to be large, which improves the feeding efficiency of the added material. Finally, it is added into the single crystal furnace according to a predetermined trajectory through the material guide pipe, ensuring that the added material does not volatilize prematurely, thereby improving the quality of the obtained silicon wafers.

[0018] Optionally, the feeding device also includes: the feeding device also includes a feeding mechanism, the feeding mechanism is used to add additives into the warehouse body and / or the material pipe, the feeding mechanism includes a material cup located in the warehouse body and / or the material pipe, a driving member at least partially located outside the warehouse body and / or the material pipe, and a rotating shaft connected between the driving member and the material cup, the driving member is connected to the rotating shaft to drive the rotating shaft to drive the material cup to rotate, so as to pour the additives in the material cup into the warehouse body and / or the material pipe.

[0019] Since the feeding mechanism realizes feeding by rotating the material cup, the supply amount of the added material in the material cup can be accurately controlled, and the real-time online supply of the added material can be realized, thereby improving the feeding efficiency and the stability of the crystal pulling operation.

[0020] Optionally, the feeding device further comprises: the feeding mechanism is connected to the bin body and at least partially extends into the bin body, the feeding mechanism is used to transport the additive from the bin body to the material cup, the feeding mechanism comprises a push rod and a feeding channel, the feeding channel at least partially extends into the bin body; wherein the push rod is movably connected in the feeding channel, the push rod is used to push the additive in the feeding channel into the material cup. The feeding mechanism adds the additive into the material cup by automatic feeding, avoiding the operation of adding the additive into the material cup by manual operation, so as to improve the feeding efficiency.

[0021] In a second aspect, the present application also discloses a single crystal furnace, comprising a furnace body and any one of the above-mentioned feeding devices; the feeding device is arranged in the furnace body, the bin body is at least partially located outside the furnace body, and the discharge section of the material pipe is located in the furnace body.

[0022] Optionally, the furnace body includes a furnace body and a furnace cover arranged 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 100 mm to 400 mm.

[0023] According to the technical solution of the present application, the vertical height between the discharge section and the uppermost edge of the furnace cover is 100 mm to 400 mm. That is, the discharge section at least partially extends to the top of the thermal field component in the single crystal furnace, so as to introduce the additive into the single crystal furnace so that the additive falls from the top of the thermal field component into the crucible. At this time, the discharge section is far away from the crucible, and is less affected by the high temperature environment near the crucible, thereby avoiding the problem of impurity introduction and additive loss caused by premature melting or volatilization of the additive in the discharge section, further improving the control of the additive amount, and being conducive to obtaining silicon rods with better quality, thereby making the prepared silicon wafers of higher quality; at the same time, the discharge section will not touch the thermal field components and other structures in the single crystal furnace, affecting the stability of crystal pulling.

[0024] It should be noted that in the embodiments of the present application, the structure of the feeding device is the same as the structure of any of the feeding devices described above, and its beneficial effects are also similar, which will not be elaborated here.

[0025] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0027] Figure 1 It is a structural schematic diagram of a single crystal furnace using a feeding mechanism as described in an embodiment of the application;

[0028] Figure 2 yes Figure 1 A schematic diagram of a partial structure of a single crystal furnace shown;

[0029] Figure 3 yes Figure 1 The enlarged structural schematic diagram of the single crystal furnace S position shown;

[0030] Figure 4 is a schematic structural diagram of another feeding device described in an embodiment of the present application;

[0031] Figure 5 It is a structural schematic diagram of another feeding device described in an embodiment of the present application.

[0032] Figure 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 - warehouse body, 730 - inner cavity, 74 - warehouse cover, 75 - rotating shaft, 751 - weighing sensor, 76 - material pipe seat, 77 - material cup, 78 - material storage mechanism, 79 - material guide pipe, 791 - material discharge section, 792 - connecting section, 793 - connecting section, 710 - feeding channel, 711 - feeding pipe, 712 - driving member, 713 - feeding mechanism, 714 - push rod, 715 - feeding channel. DETAILED DESCRIPTION

[0033] Embodiments of the present invention will be described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0034] The term "first" or "second" in the specification and claims of the present application may include one or more of the features explicitly or implicitly. In the description of the present invention, unless otherwise specified, "plurality" means two or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally means that the objects connected before and after are in an "or" relationship.

[0035] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0036] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] The embodiment of the present application provides a feeding device, which 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 other materials other than silicon materials, such as dopants, impurity removers, etc. This application only takes the additive as a dopant as an example for explanation, and other types of additives can be implemented by reference.

[0038] The material pipe in the present application can be a tubular structure, which is used to connect the bin body so that the added material in the bin body flows out to a predetermined position. For those skilled in the art, the material pipe can be a material guide pipe or a structure including a material guide pipe and a feeding pipe. The material guide pipe and the feeding pipe can be integrated into an integral structure or can be designed separately. Those skilled in the art can choose according to their needs. In the embodiments of the present application, the material pipe is taken as an example for description.

[0039] Reference Figure 1 , showing a schematic diagram of the structure of a single crystal furnace using a charging device according to an embodiment of the application, referring to Figure 2 , showing Figure 1 The schematic diagram of the partial structure of the single crystal furnace is shown in FIG. Figure 1 As shown, the single crystal furnace includes a furnace body 1, a crucible 4 and a thermal field component 6 located in the furnace body 1, and the thermal field component 6 is located above the crucible 4. The crucible 4 and the thermal field component 6 can be enclosed to 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 single crystal silicon rod to pass through.

[0040] The feeding device of the present application includes: a bin body 73 and a material pipe; one end of the material pipe is connected to the bin 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 bin body 73 is B, wherein 50mm≤B≤800mm.

[0041] In the embodiment of the present application, the material pipe is described by taking the material guide pipe as an example. Figure 2As shown, the feeding device 7 may specifically include: a warehouse body 73 with an inner cavity 730, a material guide pipe 79; one end of the material guide pipe 79 is connected to the warehouse body 73; the other end of the material guide pipe 79 is provided with a discharge section 791, and the minimum distance between the discharge section 791 and the warehouse body 73 is B, where 50mm≤B≤800mm, so as to introduce the added material into the furnace body 1 and make the added material fall from the crystal growth channel 61 into the crucible 4 without touching the heat exchanger and other components in the furnace body 1, affecting the stability of subsequent crystal pulling. When the distance B is less than 50mm, the heat exchanger and other components in the furnace body 1 will be touched during the operation of adding materials, affecting the crystal pulling stability of the single crystal furnace; when the distance B is greater than 800mm, the feeding efficiency of the added material is affected due to the long distance between the material guide pipe 79 and the warehouse body 73.

[0042] It should be noted that the minimum distance refers to the vertical distance between the material segment 791 and the central axis of the silo 73. It can be understood that when the discharge segment 791 has a certain length, the distance refers to the vertical distance between the farthest point in the material segment 791 away from the silo and the central axis of the silo.

[0043] For those skilled in the art, the feeding device has a discharge port on its bin body, which is the location where the added material flows out of the bin body 73. It can be rectangular or funnel-shaped, etc. The added material coming out of the discharge port is added to the material guide pipe and then added to the single crystal furnace through the material guide pipe. This application does not limit the shape of the discharge port.

[0044] The feeding device of the embodiment of the present application may also include a feeding pipe 711 having a feeding channel 710 and a guide pipe 79; the feeding pipe 711 is connected to the discharge port of the bin body 73, and the feeding channel 710 is in communication with the inner cavity 730; one end of the guide pipe 79 is connected to the feeding channel 710. In the embodiment of the present application, the feeding device 7 can be used in a single crystal furnace. During the process of pulling a single crystal silicon rod in the single crystal furnace, the feeding device 7 can add additives to the furnace body 1 at an appropriate time according to actual needs. In this way, the problem of the additive being easy to volatilize in the high temperature environment of the single crystal furnace can be avoided, which is conducive to obtaining a silicon rod that matches the theoretical target design resistivity. Moreover, the operation of stopping the furnace to add additives can be avoided, which is conducive to improving the drawing efficiency of the silicon rod. In addition, the minimum distance between the discharge section 791 and the warehouse body 73 is 50mm≤B≤800mm. The additive 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 away from the crucible 4, it is less affected by the high temperature environment near the crucible 4, thereby avoiding the introduction of impurities and the loss of additives caused by premature melting or volatilization of the additives in the discharge section 791, further improving the control of the concentration quality of the additives, and facilitating obtaining silicon rods with better quality.

[0045] In a specific application, the furnace body 1 serves as the structural main body of the single crystal furnace, and is provided with components such as a crucible 4, a thermal field component 6, a heater 2, and a heat preservation tube 3. The crucible 4 can be used to hold polysilicon raw materials; the heater 2 can be arranged on the side or bottom of the crucible 4, and the heater 2 can be used to heat the polysilicon raw materials in the crucible 4 to melt the polysilicon raw materials into silicon liquid 5; the thermal field component 6 can be located above the crucible 4, and the thermal field component 6 is provided with a crystal growth channel 61 for the single crystal silicon rod to pass through, and the thermal field component 6 can be used to maintain a thermal field environment suitable for the crystal pulling operation. For example, the thermal field component 6 can be, but is not limited to, a heat shield or a heat exchanger. The embodiment of the present application is only described by taking the thermal field component 6 as a heat exchanger as an example, and other types of thermal field components 6 can be implemented by reference. The heat preservation tube 3 can be sleeved outside the crucible 4 and the thermal field component 6, and the heat preservation tube 3 can be used to avoid heat loss.

[0046] In the embodiment of the present application, the feeding device 7 can be used in conjunction with the single crystal furnace. During the process of the single crystal furnace pulling a single crystal silicon rod, the feeding device 7 can add additives to the furnace body 1 in real time at an appropriate time according to actual needs. For example, after the polycrystalline silicon raw material in the crucible 4 is melted to a certain degree or completely melted, the feeding device 7 can be started to add the additives to the crucible 4.

[0047] In practical applications, for common additives such as indium, arsenic, antimony and gallium, their melting points are usually much lower than the melting point of polysilicon raw materials (usually around 1420 degrees). Compared with the traditional method of adding additives, that is, adding the additives together with the polysilicon raw materials into the crucible 4 causes the problem of premature volatilization of the additives, the feeding method described in the embodiment of the present application can achieve real-time addition of additives, that is, during the process of pulling the silicon rod, the feeding device 7 can be used to add the additives to the furnace body 1 at any time according to actual needs to avoid premature volatilization of the additives.

[0048] Moreover, during the drawing process of the single crystal silicon rod, the area with higher temperature is near the heater 2 and the crucible 4. Since the minimum distance between the discharge section 791 at the end of the guide tube 79 of the feeding device 7 of the present application, which is far away from the warehouse body, and the warehouse body is between 50mm and 800mm, the distance between the discharge section 791 and the high-temperature area formed near the crucible 4 is reasonably set, and the influence of the high-temperature area is small, which can avoid the blockage of the guide tube 79 caused by the early melting of the additive in the discharge section 791. In addition, since the additive can fall into the crucible 4 along the crystal growth channel 61 after being output from the discharge section 791, that is, the additive is added to the crucible 4 in the form of solid, rather than being added to the crucible 4 in the form of gas after being heated and vaporized in advance, it can avoid the defect of failing to reach the target doping concentration due to the gaseous additive being blown away by the inert gas in the furnace body 1, and it is impossible to obtain a silicon rod with good resistivity consistency, thereby affecting the preparation of high-quality silicon wafers.

[0049] Reference Figure 3 , showing Figure 1 The enlarged structural diagram of the single crystal furnace S position is shown in FIG. Figure 3 As shown, a connecting section 792 is provided at one end of the guide tube 79 connected to the discharge section 791, and 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 thermal field component 6 to the crucible 4, avoiding the additive particles from colliding with the inside of the heat exchanger when falling.

[0050] It should be noted that the value of the first angle r needs to be determined based on factors such as the size of the furnace body 1, the size and layout of the thermal field component 6, the distance between the discharge section 791 and the thermal field component 6, and the particle size of the added material, so as to control the added material particles to fall from the preset position of the crystal growth channel 61 of the thermal field component 6 and not volatilize prematurely.

[0051] For example, the value of the first angle r can be 20 degrees, 30 degrees, 38 degrees, 45 degrees or 60 degrees, etc. The embodiment of the present application does not specifically limit the value of the first angle r.

[0052] like Figure 2 As shown, the material 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 warehouse body 73 than the connecting section 793, and the connecting section 793 is connected between the connecting section 792 and the discharge section 791, wherein the angle between the connecting section 793 and the connecting section 792 is the second angle, and the angle between the discharge section 791 and the connecting section 793 is the third angle, and the third angle is greater than or equal to the second angle.

[0053] In a specific application, after the added material enters the material guide tube 79 from the feeding channel 710, it can pass through the connecting section 792, the connecting section 793 and the discharging section 791 in sequence, and finally be discharged from the discharging section 791 and fall into the crucible 4. Figure 2 As shown, the end of the connecting section 792 extending into the feeding channel 710 is provided with a trumpet-shaped opening, so that the additive in the feeding channel 710 can smoothly enter the connecting section 792. Since the third angle β between the discharge section 791 and the connecting section 793 is greater than or equal to the second 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, so that the discharge section 791 can extend to the top of the crystal growth channel 61, so that the additive particles can fall from the crystal growth channel 61 to the crucible 4, and avoid the additive particles from colliding with the inside of the heat exchanger when falling.

[0054] Optionally, the second angle α and the third angle β are both greater than 90 degrees, that is, the second angle α and the third angle β are both obtuse angles. In this way, the stress on the added material when passing through the connection between the connecting section 792 and the connecting section 793, and the connection between the connecting section 793 and the discharging section 791 is relatively small, which can effectively avoid the accumulation of the added material at these two connections, thereby facilitating the smooth passage of the added material through the entire guide pipe 79.

[0055] Optionally, the angle range of the second angle α is 110 degrees to 150 degrees, and the angle range of the third angle β is 110 degrees to 150 degrees. This can not only facilitate the smooth passage of the additive through the guide tube 79, but also better control the falling path of the additive, so that the additive can fall from the central area of ​​the crystal growth channel 61 of the heat exchanger into the crucible 4, which can prevent the additive from colliding with the inside of the heat exchanger and preventing the additive from volatilizing prematurely.

[0056] It should be noted that the values ​​of the second angle α and the third angle β need to be determined based on factors such as the size of the furnace body 1, the size and layout of the thermal field component 6, the distance between the discharge section 791 and the thermal field component 6, and the particle size of the additive, so as to control the additive particles to fall from the center position of the crystal growth channel 61 of the thermal field component 6 and not volatilize prematurely as the ultimate control goal.

[0057] For example, the value of the second angle α can be 110 degrees, 120 degrees, 125 degrees, 135 degrees or 150 degrees, etc., the value of the third angle β can be 110 degrees, 120 degrees, 125 degrees, 135 degrees or 150 degrees, etc., and the values ​​of the second angle α and the third angle β can be the same or different. The embodiment of the present application does not specifically limit the values ​​of the second angle α and the third angle β.

[0058] Optionally, the material pipe includes a material guide pipe 79 , the material discharge section 791 is located in the material guide pipe 79 , and the material pipe also includes a feeding pipe 711 , which is connected between the bin body 73 and the material guide pipe 79 , and the inner diameter of the feeding pipe 711 is greater than the outer diameter of the material guide pipe 79 .

[0059] Through the setting of the feeding pipe and the guide pipe, after the added material enters from the warehouse body, 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 added material passes through the feeding pipe with a wider path after being added to the warehouse body, so that more added material is added from the feeding device, increasing the feeding amount. At the same time, the inner diameter of the feeding pipe above is set to be large, which improves the feeding efficiency of the added material. Finally, it is added into the single crystal furnace according to a predetermined trajectory through the guide pipe, ensuring that the added material does not volatilize prematurely, thereby improving the quality of the obtained silicon wafers.

[0060] Optionally, a funnel structure is provided on one end of the material guide tube 79 away from the material discharge section 791 , and the material guide tube 79 is connected to the feeding tube 711 via the funnel structure.

[0061] Since the inner diameter of the feeding tube is large, the funnel structure arranged on the material guide tube can provide a certain buffer for the added material, thereby preventing the added material falling from the feeding tube from being added into the material guide tube.

[0062] like Figure 3 As shown, the length h of the discharge section 791 ranges from 30 mm to 50 mm, so as to control the length of the discharge section 791 within a suitable range. In this way, the falling path of the added material output by the discharge section 791 can be controlled within a reasonable range, and at the same time, the distance between the discharge section 791 and the thermal field component 6 and the single crystal silicon rod can be well controlled, which is convenient for the layout of the guide pipe 79 in the furnace body 1.

[0063] 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 thermal field component 6, and the particle size of the additive, so as to control the additive particles to fall from the center position of the crystal growth channel 61 of the thermal field component 6 and not volatilize prematurely as the ultimate control goal.

[0064] 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. The embodiment of the present application does not specifically limit the length h of the discharge section 791.

[0065] like Figure 2 As shown, the feeding device 7 may further include a support 71 and a material pipe seat 76. The support 71 may be connected to the furnace body 1 to support the bin body 73. The material pipe seat 76 may be connected to the bottom of the feeding channel 710 to support the material guide pipe 79.

[0066] In practical applications, the furnace body 1 may include a furnace body and a furnace cover arranged above the furnace body 1. 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 additional material into the furnace body 1 from the side of the furnace body 1, the support 71 may be connected to the furnace body or the furnace cover. When the feeding device 7 needs to add the additional material into the furnace body 1 from the top of the furnace body 1, the support 71 may be connected to the furnace cover. For those skilled in the art, the feeding device may also be arranged on the side of the furnace body of the single crystal furnace.

[0067] In some optional embodiments of the present application, the feeding device 7 may further include: a feeding mechanism and a storage mechanism 78, wherein the feeding mechanism and the storage mechanism 78 are both arranged in the inner cavity 730, and the feeding mechanism can be used to add the additive into the storage mechanism 78, and the storage mechanism 78 at least partially extends into the feeding channel 710 to introduce the additive into the feeding channel 710.

[0068] In some optional embodiments of the present application, the feeding device further includes an air pressure regulating mechanism, which is at least partially disposed in the inner cavity 730, and the air pressure regulating mechanism can be used to regulate the air pressure in the inner cavity 730. When the air pressure in the inner cavity 730 is adjusted to be consistent with the air pressure environment in the furnace body 1, the additional material is added into the furnace body 1, so that the air field environment in the furnace body 1 is not affected during the feeding process, thereby improving the stability of the crystal pulling operation.

[0069] In actual application, when the feeding device 7 is used to add the added material into the furnace body 1, since the inner cavity 730 and the furnace body 1 are connected, when the air pressure conditions in the inner cavity 730 and the furnace body 1 are inconsistent, the airflow in the inner cavity 730 is easy to rush into the furnace body 1, or the airflow in the furnace body 1 is easy to overflow into the inner cavity 730. In this way, the airflow in the furnace body 1 will be turbulent, affecting the stability of the gas field environment in the furnace body 1.

[0070] In an embodiment of the present application, an air pressure regulating mechanism can be provided in the feeding device 7, and the air pressure regulating mechanism can be at least partially located in the inner cavity 730. Before starting the feeding device 7 to add the additional material, the air pressure regulating structure can be used to adjust the air pressure in the inner cavity 730 to be consistent with the air pressure of the furnace body 1. In this way, the phenomenon of air flow turbulence in the furnace body 1 during the feeding process can be avoided.

[0071] 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 (such as Figure 2As shown), the isolation valve 72 can be used to control the interruption of the air flow between the inner cavity 730 and the furnace body 1; wherein, when the air pressure in the inner cavity 730 is consistent with the air pressure in the furnace body 1, the isolation valve 72 is opened.

[0072] For those skilled in the art, the isolation valve can be a gate valve, a ball valve, etc. that controls the on and off of the airflow. In the present application, the isolation valve adopts a ball valve because of its economy and simple structure. Those skilled in the art can reasonably select the type of isolation valve according to the specific situation, and the present application does not limit this.

[0073] Specifically, the air pressure regulating mechanism can detect the pressure value of the inner cavity 730 in real time. The air inlet can be used to pass gas into the inner cavity 730, and the air outlet can be used to discharge the gas in the inner cavity 730 to the outside of the inner cavity 730. By controlling the operation of passing gas through the air inlet or controlling the operation of discharging gas through the air outlet, the air pressure in the inner cavity 730 can be adjusted. In practical applications, when there is no need to add additives, the isolation valve 72 can be in a closed state to cut off the connection between the inner cavity 730 and the furnace body 1. When it is necessary to add additives, the cavity pressure value of the inner cavity 730 can be obtained through a pressure gauge, and the cavity pressure value can be compared with the furnace pressure value. When the cavity pressure value is less than the furnace pressure value, the air inlet is controlled to ventilate the inner cavity 730, and when the cavity pressure value is greater than the furnace pressure value, the air outlet is controlled to discharge part of the gas in the inner cavity 730 until the cavity pressure value is consistent with the furnace pressure value. Then, the isolation valve 72 is opened to allow the inner cavity 730 to communicate with the furnace body 1 , so as to facilitate the operation of adding the doping material into the furnace body 1 .

[0074] Reference Figure 4 , shows a schematic diagram of the structure of another feeding device described in an embodiment of the present application, such as Figure 4 As shown, the feeding device 7 is not provided with a gas pressure regulating structure, and accordingly, there is no need to provide an isolation valve 72 in the feeding channel 710 of the feeding pipe 711. In this way, the structure of the feeding pipe 711 can be made simpler, which is conducive to simplifying the overall structure of the feeding device 7 and facilitating the layout of the feeding device 7 on the single crystal furnace.

[0075] In some optional embodiments of the present application, the feeding device further includes a feeding mechanism, which is used to add the additive into the warehouse body 73 and / or the material guide tube 79. The feeding mechanism includes a material cup 77 located in the warehouse body 73 and / or the material guide tube, a driving member 712 at least partially located outside the warehouse body 73 and / or the material guide tube 79, and a rotating shaft 75 connected between the driving member 712 and the material cup 77. The driving member 712 is connected to the rotating shaft 75 to drive the rotating shaft 75 to drive the material cup 77 to rotate, so as to pour the additive in the material cup 77 into the warehouse body 73 and / or the material guide tube 79. Since the feeding mechanism is connected to the rotating shaft through the driving member, the material cup is driven to rotate to realize the feeding, and the supply amount of the additive in the material cup can be accurately controlled, and the real-time online supply of the additive is realized, thereby improving the feeding efficiency and the stability of the crystal pulling operation.

[0076] like Figure 2 As shown, the feeding mechanism may specifically include: a material cup 77, a rotating shaft 75 and a driving member 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 member 712 is connected to the rotating shaft 75 to drive the rotating shaft 75 to drive the material cup 77 to rotate, so as to pour the added material in the material cup 77 into the storage mechanism 78.

[0077] In actual application, the weighed additive can be put into the material cup 77 , and then the driving member 712 is started to drive the rotating shaft 75 to drive the material cup 77 to rotate, so as to pour the additive in the material cup 77 into the material storage mechanism 78 .

[0078] like Figure 2 As shown, the feeding device 7 may further include a bin cover 74, which is detachably connected to the top of the bin body 73 and encloses the bin body 73 to form an inner cavity 730. Usually, in the process of manual feeding, after the additives to be added are weighed, the bin cover 74 can be removed, and the additives are added to the material cup 77, and then the bin cover 74 is covered on the bin body 73.

[0079] like Figure 2 As shown, the material storage mechanism 78 may specifically include a funnel, which is arranged opposite to the material cup 77 so as to facilitate the introduction of the additive in the material cup 77 into the funnel. In practical applications, the end of the funnel close to the material cup 77 may be provided with a trumpet-shaped opening so that the funnel can receive the additive poured from the material cup 77 and prevent the additive from falling into the area outside the funnel.

[0080] Reference Figure 5 , shows a schematic structural diagram of another feeding device described in an embodiment of the present application, such as Figure 5As shown, the feeding device 7 may also include: a feeding mechanism 713, which is connected to the bin body 73 and at least partially extends 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 by automated feeding, thereby avoiding the operation of adding the additive to the material cup 77 by manual operation, so as to improve the feeding efficiency.

[0081] Optionally, the feeding mechanism 713 is connected to the bin body 73 and at least partially extends into the bin body 73. The feeding mechanism 713 is used to transport the added material from the bin body 73 to the material cup 77. The feeding mechanism 713 includes a push rod 714 and a feed channel 715. The feed channel 715 at least partially extends into the bin body 73; wherein the push rod 714 is movably connected in the feed channel 715, and the push rod 714 is used to push the added material in the feed channel 715 into the material cup 77.

[0082] In practical applications, such as Figure 5 As shown, a weighing sensor 751 can also be provided on the rotating shaft 75, and the weighing sensor 751 can be used to weigh the weight of the additive. Specifically, the additive can be added to the feed channel 715, and then the push rod 714 is used to push the additive to move in the feed channel 715 until the additive falls into the material cup 77. The weighing sensor 751 can be used to weigh the weight of the additive in the material cup 77. After the additive in the material cup 77 reaches a preset target weight, the rotating shaft 75 can drive the material cup 77 to rotate, and pour the additive in the material cup 77 into the material storage mechanism 78.

[0083] In some other optional embodiments of the present application, the material of the material cup 77, the material storage mechanism 78, the material feeding tube 711 and the material guide 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 guide tube 79 need to be in direct contact with the additive, when the material of the above components is all quartz with stable performance, it is not easy to introduce new impurities during the addition of the additive, which is beneficial to the quality control of the single crystal silicon rod.

[0084] It should be noted that the material of the material cup 77, the material storage mechanism 78, the feeding tube 711 and the material guide tube 79 can also be other materials that are not easy to react with the additive, and the embodiment of the present application does not limit this.

[0085] In summary, the feeding device described in the embodiment of the present application can at least include the following advantages:

[0086] In the embodiment of the present application, the feeding device can be used in a single crystal furnace. In the process of drawing a single crystal silicon rod in the single crystal furnace, the feeding device can add additives to the furnace body at an appropriate time according to actual needs. In this way, the problem of the additives being easily volatilized due to the addition of the additives to the crucible together with the polysilicon raw material and melting at high temperature can be avoided, which is conducive to obtaining a silicon rod that matches the theoretical target design resistivity. Moreover, the operation of stopping the furnace to add additives can be avoided, which is conducive to improving the drawing efficiency of the silicon rod. In addition, since the discharge section of the guide pipe is inclined downward relative to the vertical direction and at least partially extends above the crystal growth channel, the additives coming out of the discharge section can fall from the crystal growth channel of the thermal field component into the crucible. Since the discharge section is far away from the crucible, it is less affected by the high temperature environment near the crucible. It can also avoid the introduction of impurities and the loss of additives caused by the premature melting or volatilization of the additives in the discharge section, further improving the control of the concentration quality of the additives, which is conducive to obtaining silicon rods with better quality.

[0087] The present application also provides a Figure 1 The single crystal furnace shown in Figure 1 As shown, the single crystal furnace includes: a furnace body 1 and a feeding device 7 as described in any of the above embodiments; the feeding device 7 is arranged on the furnace body 1, the warehouse body 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.

[0088] It should be noted that in the embodiment of the present application, the structure of the feeding device 7 is the same as the structure of the feeding device 7 described in any of the above embodiments, and its beneficial effects are also similar, which will not be repeated here.

[0089] like Figure 1 As shown, the single crystal furnace may also include a heater 2 and a crucible 4; wherein the crucible 4 and the heater 2 are both located in 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 feed guide pipe 79 of the feeding device 7 at least partially extends to the top of the crystal growth channel 61, so as to introduce the added material into the furnace body 1 and allow the added material to fall from the crystal growth channel 61 into the crucible 4.

[0090] In the process of drawing single crystal silicon rods in the single crystal furnace, the feeding device 7 can add additives to the furnace body 1 at an appropriate time according to actual needs. In this way, the problem of easy volatilization of additives caused by adding additives together with polysilicon raw materials to the crucible 4 can be avoided, which is conducive to obtaining silicon rods matching the theoretical target design resistivity. Moreover, the operation of stopping the furnace to add additives can be avoided, which is conducive to improving the drawing 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 at least partially extends to the top of the crystal growth channel 61, the additives coming out of the discharge section 791 can fall from the crystal growth channel 61 of the thermal field component 6 into the crucible 4. Since the discharge section 791 is far away from the crucible 4, it is less affected by the high temperature environment near the crucible 4. It can also avoid the introduction of impurities and the loss of additives caused by the premature melting or volatilization of the additives in the discharge section 791, further improving the control of the concentration quality of the additives, which is conducive to obtaining silicon rods with better quality.

[0091] Optionally, the furnace body 1 includes a furnace body and a furnace cover arranged 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 100 mm to 400 mm.

[0092] Since the vertical height between the discharge section 791 and the uppermost edge of the furnace cover is 100 mm to 400 mm, that is, the discharge section at least partially extends to the top of the thermal field component 6 in the single crystal furnace, so as to introduce the additive into the single crystal furnace so that the additive falls from the top of the thermal field component 6 into the crucible 4. The discharge section 791 is far away from the crucible 4, and is less affected by the high temperature environment near the crucible 4, thus avoiding the problem of impurity introduction 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, and being conducive to obtaining silicon rods with better quality, thereby making the prepared silicon wafers of higher quality; at the same time, the discharge section will not touch the thermal field components and other structures in the single crystal furnace, affecting the stability of crystal pulling.

[0093] It should be further explained that the shape of the furnace cover of a single crystal furnace is usually circular or elliptical. The top edge of the furnace cover can be understood as the position on the furnace cover that is farthest from the horizontal plane where the bottom of the furnace body is located. The farthest position can be the vertex position of the circular or elliptical structure. Therefore, the vertical height between the discharge section and the top edge of the furnace cover refers to the vertical distance between the bottom edge of the discharge section and the top edge of the furnace cover.

[0094] In practical applications, when the feeding device 7 needs to add the additional material into the furnace body 1 from the side of the furnace body 1, 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 additional material into the furnace body 1 from the top of the furnace body 1, the support 71 of the feeding device 7 can be connected to the furnace cover. The embodiment of the present application does not specifically limit the connection position of the feeding device 7 on the furnace body 1.

[0095] In some optional embodiments of the present application, the distance between the side of the discharge section 791 close to the center of the furnace body 1 and the center line of the furnace body 1 is A, which satisfies 150mm≤A≤500mm. In specific applications, when the distance A is less than 150mm, the feeding efficiency of the added material is affected due to the long distance between the material guide pipe 79 and the bin body 73; when the distance A is greater than 500mm, the heat exchanger and other components in the furnace body 1 will be touched during the operation of adding materials, affecting the crystal pulling stability of the single crystal furnace.

[0096] In some other optional embodiments of the present application, the distance between the central axis of the feeding device 7 and the side wall of the furnace body 1 is C, which satisfies 50mm≤C≤800mm, so as to take into account both the feeding efficiency and the crystal pulling stability by controlling the distance between the feeding device 7 and the side wall of the furnace body. In a specific application, when the distance C is less than 50mm, the feeding efficiency of the added material is affected due to the long distance between the feeding device 7 and the crystal growth channel 61; when the distance C is greater than 800mm, during the operation of adding material, the added material dropped from the feeding device 7 will touch the heat exchanger and other components in the furnace body 1, affecting the crystal pulling stability of the single crystal furnace, because the feeding device 7 is too close to the crystal growth channel 61.

[0097] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0098] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A feeding device (7), characterized in that: The feeding device (7) comprises: a bin body (73) and a feeding pipe; One end of the material pipe is connected to the bin 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 body (73) is B, where 50mm≤B≤800mm.

2. The feeding device (7) according to claim 1, characterized in that 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, characterized in that: The material pipe includes a material guide pipe (79), the material discharge section (791) is located in the material guide pipe (79), and the material 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 warehouse body (73) than the connecting section (793), and the connecting section (793) is connected between the connecting section (792) and the material discharge section (791), wherein the angle between the connecting section (793) and the connecting section (792) is a second angle, and the angle between the material discharge section (791) and the connecting section (793) is a third angle, and the third angle is greater than or equal to the second angle.

4. The feeding device according to claim 3, characterized in that: The second angle and the third angle are both greater than 90 degrees.

5. The feeding device (7) according to claim 3, characterized in that: The second angle or the third angle is 110 degrees to 150 degrees.

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

7. The feeding device (7) according to claim 6, characterized in that A funnel structure is provided on one end of the material guide pipe (79) away from the material discharge section (791), and the material guide pipe (79) is connected to the feeding pipe (711) via the funnel structure.

8. The feeding device (7) according to claim 1, characterized in that The feeding device also includes a feeding mechanism, which is used to add additives into the warehouse body (73) and / or the material pipe. The feeding mechanism includes a material cup (77) located in the warehouse body (73) and / or the material pipe, a driving member (712) at least partially located outside the warehouse body (73) and / or the material pipe, and a rotating shaft (75) connected between the driving member (712) and the material cup (77). The driving member (712) is connected to the rotating shaft (75) to drive the rotating shaft (75) to drive the material cup (77) to rotate, so as to pour the additives in the material cup (77) into the warehouse body (73) and / or the material pipe.

9. The feeding device (7) according to claim 8, characterized in that The feeding device (7) further comprises a feeding mechanism (713), the feeding mechanism (713) being connected to the bin body (73) and at least partially extending into the bin body (73), the feeding mechanism (713) being used to transport the added material from the bin body (73) to the material cup (77), the feeding mechanism (713) comprising a push rod (714) and a feeding channel (715), the feeding channel (715) at least partially extending into the bin body (73); wherein, The push rod (714) is movably connected in the feed channel (715), and the push rod (714) is used to push the added material in the feed channel (715) into the material cup (77).

10. The feeding device (7) according to claim 8, characterized in that The feeding device further comprises a material storage mechanism (78), wherein the material storage mechanism (78) is located between the feeding mechanism and the material pipe, and the material storage mechanism (78) comprises a funnel, wherein the funnel is arranged opposite to the material cup (77).

11. A single crystal furnace, characterized in that: The single crystal furnace comprises: a furnace body (1) and a charging device (7) according to any one of claims 1 to 10; The feeding device (7) is arranged on the furnace body (1), the warehouse body (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, characterized in that: The distance between the side of the discharge section (791) close 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 warehouse body (73) and the side wall of the furnace body is 50mm≤C≤800mm.

13. The single crystal furnace according to claim 11, characterized in that: The single crystal furnace further comprises a gas pressure regulating mechanism, wherein the gas pressure regulating mechanism comprises an isolation valve (72) arranged on the material pipe, and the isolation valve (72) is used to isolate or connect the warehouse body (73) and the furnace body (1).

14. The single crystal furnace according to claim 11, characterized in that: The furnace body (1) comprises a furnace body and a furnace cover arranged 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 100 mm to 400 mm.

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