Guide cylinder structure for single crystal furnace and single crystal furnace

Abstract

The utility model discloses a flow guide cylinder structure for a single crystal furnace and the single crystal furnace, the flow guide cylinder structure is suitable for being installed above a crucible of the single crystal furnace, the flow guide cylinder structure comprises a flow guide inner cylinder and a flow guide outer cylinder, the flow guide inner cylinder is installed in the flow guide outer cylinder, and a heat insulation space is formed between the flow guide inner cylinder and the flow guide outer cylinder; the air guide flow channel is formed in the side wall of the flow guide outer cylinder, an air inlet and an air outlet which are communicated with the air guide flow channel are formed in the flow guide outer cylinder, and the air outlet is formed in the lower portion of the flow guide outer cylinder and is open towards the interior of the crucible. According to the guide cylinder structure for the single crystal furnace disclosed by the embodiment of the utility model, inert gas can flow between the crucible and the lower part of the guide cylinder structure through the gas guide flow channel, so that gas backflow between the lower part of the guide cylinder structure and the upper part of a liquid level is avoided, and the flow velocity of gas near a solid-liquid interface can be increased; the cooling effect on the crystal generating position of the single crystal silicon rod is guaranteed, the oxygen content concentration in the crystal can be reduced, the quality of the single crystal silicon rod is guaranteed, the setting cost is low, and maintenance is convenient.

Description

TECHNICAL FIELD

[0001] The utility model relates to monocrystalline silicon manufacturing technical field especially, it relates to a guide tube structure for single crystal furnace and single crystal furnace. BACKGROUND

[0002] Monocrystalline silicon is an important component of crystal materials as a kind of more active non-metallic element crystal. In the process of growing monocrystalline silicon rod, as the diameter of the crystal increases, the diameter of the crucible increases accordingly, and the heating power also increases. Large quartz crucibles bear higher temperatures than small quartz crucibles, the heat convection in the melt intensifies, the reaction between the quartz crucible and the molten silicon intensifies, and more SiO is produced. Part of the SiO produced in the crucible enters the single crystal, causing the oxygen content concentration in the crystal to increase, resulting in defects such as dislocation loops, oxygen precipitates and thermal induced defects.

[0003] Now the inert gas can be made to flow near the solid-liquid interface of the monocrystalline silicon rod to speed up the cooling efficiency and reduce the oxygen content concentration in the crystal. The guide tube is used to guide the inert gas to ensure that the inert gas flows accurately near the solid-liquid interface. However, when the existing guide tube guides the inert gas to the solid-liquid interface, the inert gas flow rate is low, which can cause gas backflow outside the guide tube, resulting in uneven cooling of the monocrystalline silicon rod growth position in all directions, and causing the oxygen content concentration in the crystal to be high, which affects the quality of the monocrystalline silicon rod, and there is room for improvement. SUMMARY

[0004] The utility model aims at solving one of the technical problems existing in the prior art. To this end, the utility model provides a guide tube structure for a single crystal furnace, which is low in cost, easy to maintain, can reduce gas backflow, ensure the cooling effect of the single crystal silicon rod growth position, and reduce the oxygen content concentration in the crystal to ensure the quality of the single crystal silicon rod.

[0005] The guide tube structure for a single crystal furnace according to the utility model embodiment is suitable for being installed above the crucible of the single crystal furnace, and comprises: a guide inner tube and a guide outer tube, the guide inner tube is installed in the guide outer tube, and a heat insulation space is formed between the guide inner tube and the guide outer tube; a gas flow channel is formed in the side wall of the guide outer tube, the guide outer tube is provided with a gas inlet and a gas outlet communicating with the gas flow channel, and the gas outlet is arranged at the lower part of the guide outer tube and opens towards the inside of the crucible.

[0006] According to the present invention, a flow guide tube structure for a single crystal furnace is provided at the lower part of the outer flow guide tube, with an outlet opening towards the crucible. The outlet can communicate with the flow guide channel, allowing inert gas to flow through the flow guide channel to the lower part between the crucible and the flow guide tube structure. This avoids gas backflow between the lower part of the flow guide tube structure and the liquid surface, thereby increasing the gas flow rate near the solid-liquid interface, ensuring the cooling effect on the crystal growth position of the single crystal silicon rod, reducing the oxygen concentration in the crystal, ensuring the quality of the single crystal silicon rod, having low setup cost, being easy to maintain, having better performance, and a wider range of applications.

[0007] According to some embodiments of the present invention, a flow guide tube structure for a single crystal furnace includes a flow guide channel comprising a connected inlet flow channel and an outlet flow channel. The inlet is connected to the inlet flow channel, the outlet is connected to the outlet flow channel, and the outlet flow channel is constructed as an annular flow channel.

[0008] According to some embodiments of the present invention, the flow channel for a single crystal furnace is provided as at least one;

[0009] And / or, the air outlet is provided in multiple ways, and all of the multiple air outlets are connected to the air outlet channel.

[0010] According to some embodiments of the present invention, a guide tube structure for a single crystal furnace is provided, wherein four gas outlets are provided, and the four gas outlets are all connected to the gas outlet channel and are distributed at equal intervals along the circumference of the gas outlet channel.

[0011] According to some embodiments of the present invention, a flow guide cylinder structure for a single crystal furnace includes a straight cylinder portion and an arc-shaped cylinder portion. The arc-shaped cylinder portion is connected to the lower end of the straight cylinder portion, the center of the arc-shaped cylinder portion is located inside the flow guide cylinder, and the air outlet channel is formed in the arc-shaped cylinder portion.

[0012] According to some embodiments of the present invention, the distance between the connection between the straight cylinder and the arc-shaped cylinder and the outlet air passage in the vertical direction is set as L, and satisfies: 19mm≤L≤21mm.

[0013] According to some embodiments of the present invention, the diameter of the air inlet in the guide tube structure for a single crystal furnace is set to be larger than the diameter of the guide air channel.

[0014] And / or, the diameter of the air inlet is set to be larger than the diameter of the air outlet.

[0015] According to some embodiments of the present invention, the diameter of the air inlet in the guide tube structure for a single crystal furnace is set as r1, and satisfies: 9mm≤r1≤11mm;

[0016] And / or, the diameter of the air guide channel is r2, and 4mm≤r2≤6mm is satisfied.

[0017] And / or, the diameter of the air outlet is r3, and 4mm≤r3≤6mm is satisfied.

[0018] According to the flow guide cylinder structure for the single crystal furnace of some embodiments of the present application, the included angle between the open direction of the air outlet and the horizontal plane is a, and 25°≤a≤35° is satisfied.

[0019] And / or, the inner circumferential wall of the air guide channel is provided with a flow guide film.

[0020] The utility model also proposes a single crystal furnace.

[0021] According to the single crystal furnace of the embodiment of the present application, the flow guide cylinder structure is installed in the heat preservation barrel, and at least part of the flow guide cylinder structure is placed in the crucible.

[0022] The single crystal furnace and the flow guide cylinder structure for the single crystal furnace have the same advantages as the prior art, which will not be repeated here.

[0023] The additional aspects and advantages of the present application will be partially given in the following description, partially will become obvious from the following description, or will be understood by the practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0024] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:

[0025] Figure 1 It is the structure schematic view of flow guide outer cylinder according to the flow guide outer cylinder of the embodiment of the present application;

[0026] Figure 2 It is the partial sectional view of flow guide outer cylinder according to the flow guide outer cylinder of the embodiment of the present application;

[0027] Figure 3 It is the sectional view of single crystal furnace according to the single crystal furnace of the embodiment of the present application.

[0028] REFERENCE NUMERALS:

[0029] Single crystal furnace 100,

[0030] Furnace barrel 1, furnace bottom heat preservation 11, heat preservation barrel 2, heat preservation cover 21, heat preservation barrel main body 22, crucible 3, crucible support 31, drag link 32, first heater 4, second heater 5,

[0031] The guide cylinder structure 6, the guide inner cylinder 61, the guide outer cylinder 62, the straight cylinder part 621, the arc-shaped cylinder part 622, the outer cylinder outer wall 623, the outer cylinder inner wall 624, the heat insulation space 63, the gas flow channel 64, the gas inlet 641, and the gas outlet 642. DETAILED DESCRIPTION

[0032] The embodiments of the present application are described in detail below, examples of which are shown in the drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary only, and are used only for explaining the present application, and cannot be understood as a limitation of the present application.

[0033] In the description of the present application, it should be understood that the orientation or positional relationship indicated by 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" and the like are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application. In addition, the features defined as "first" and "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0034] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0035] The following will be described with reference to Figures 1-3 The guide cylinder structure 6 for the single crystal furnace 100 according to the embodiments of the present application is described below, which is low in cost, easy to maintain, can reduce gas backflow, ensure the cooling effect on the single crystal silicon rod crystal growth position, and can reduce the oxygen content concentration in the crystal, and ensure the quality of the single crystal silicon rod.

[0036] As Figures 1-3As shown, the flow guide cylinder structure 6 for the single crystal furnace 100 according to an embodiment of the utility model, the flow guide cylinder structure 6 is suitable for being installed in the upper of the crucible 3 of single crystal furnace 100, and the flow guide cylinder structure 6 includes: flow guide inner cylinder 61, flow guide outer cylinder 62 and guide air flow 64.

[0037] Flow guide inner cylinder 61 is installed in flow guide outer cylinder 62, and the heat insulation space 63 is formed between flow guide inner cylinder 61 and flow guide outer cylinder 62, and the guide air flow 64 is formed in the side wall of flow guide outer cylinder 62, and the flow guide outer cylinder 62 is formed with the air inlet 641 and the air outlet 642 that communicate with the guide air flow 64, and the air outlet 642 is arranged in the lower part of the flow guide outer cylinder 62 and is open to the crucible 3.

[0038] Wherein, single crystal furnace 100 is a kind of in inert gas (nitrogen, helium or argon etc.) environment, with graphite heater, polycrystalline silicon etc. Polycrystalline material is melted, and the equipment for growing dislocation-free single crystal by czochralski method, mainly by main machine, heating power supply and computer control system three parts are formed. The diameter of single crystal silicon rod can be affected by temperature, pulling speed and rotational speed, crucible 3 tracking speed and rotational speed, the flow rate of protective gas and other factors during growth.

[0039] Specifically, single crystal furnace 100 is provided with crucible 3, and the crucible 3 can be quartz crucible etc., when producing single crystal silicon by czochralski method, polycrystalline silicon material is placed in crucible 3, and it is melted after high-temperature heating, and then the seed crystal is lowered to the molten polycrystalline silicon from the top, the temperature gradient of liquid surface is controlled, and the molten polycrystalline silicon is recrystallized around the seed crystal to generate single crystal silicon rod arranged in order.

[0040] Single crystal furnace 100 is also provided with flow guide cylinder structure 6, and the flow guide cylinder structure 6 is arranged above the crucible 3, and the inside of the flow guide cylinder structure 6 is provided with containing space penetrating the flow guide cylinder structure 6 in the up-down direction, the containing space can be used to contain single crystal silicon rod, and the containing space of the flow guide cylinder structure 6 can be used to guide inert gas to flow to the solid-liquid interface in the crucible 3 and the crystal growth position of single crystal silicon rod, to ensure the quality of single crystal silicon rod.

[0041] Further, the flow guide cylinder structure 6 is provided with flow guide inner cylinder 61 and flow guide outer cylinder 62, the flow guide outer cylinder 62 is arranged outside the flow guide inner cylinder 61, the flow guide outer cylinder 62 can be provided as a cylindrical structure, and the flow guide inner cylinder 61 can be provided as an inverted conical structure, and the heat insulation space 63 is formed between the flow guide inner cylinder 61 and the flow guide outer cylinder 62, and the heat insulation space 63 can be provided with heat preservation material, such as heat preservation carbon felt etc., effectively reducing the heat loss of heat field, ensuring the heat preservation performance of the flow guide cylinder structure 6, and the flow guide inner cylinder 61 and the flow guide outer cylinder 62 can be made of materials with poor thermal conductivity to shield heat and reduce the temperature of single crystal silicon rod, and in actual setting, water cooling device can also be arranged around single crystal silicon rod in the containing space to cool single crystal silicon rod and ensure the quality of single crystal silicon rod.

[0042] The side wall of the flow guide outer cylinder 62 is provided with a gas guide channel 64, that is, the gas guide channel 64 can be arranged between the outer wall 623 and the inner wall 624 of the outer cylinder. The flow guide outer cylinder 62 is also formed with an air inlet 641 and an air outlet 642, both of which are in communication with the gas guide channel 64. The air inlet 641 can be arranged at the upper part or top of the flow guide outer cylinder 62, and the air outlet 642 is arranged at the lower part of the flow guide outer cylinder 62, so that the gas can flow through the gas guide channel 64 from the upper part of the flow guide outer cylinder 62 to the lower part of the flow guide outer cylinder 62. The flow guide outer cylinder 62 is arranged outside the flow guide cylinder structure 6, so that the gas can flow through the gas guide channel 64 to the lower part of the flow guide cylinder structure 6 and flow outward from the lower part of the flow guide cylinder structure 6.

[0043] In addition, the flow guide cylinder structure 6 is arranged above the crucible 3, and the air outlet 642 can be open towards the inside of the crucible 3, so that the gas can flow through the gas guide channel 64 into the crucible 3. The gas can be an inert gas such as argon. The containing space of the flow guide cylinder structure 6 can also be open towards the inside of the crucible 3, that is, part of the gas can flow through the containing space towards the inside of the crucible 3, and part of the gas can flow through the gas guide channel 64 towards the inside of the crucible 3. The gas in the containing space can flow towards the middle part of the crucible 3. The containing space is formed in the flow guide outer cylinder 62, so that the gas in the gas guide channel 64 can flow towards the side of the crucible 3. In this way, the gas can be transported to all parts of the solid-liquid interface in the crucible 3, so as to cool all parts of the solid-liquid interface and ensure uniform cooling, thereby improving the quality of the single crystal silicon rod.

[0044] At the same time, the radial dimension of the gas guide channel 64 is small, so that the gas flow rate in the gas guide channel 64 is fast, thereby accelerating the flow rate of the gas at the solid-liquid interface when the gas flows into the crucible 3, so that the gas at the solid-liquid interface is discharged upwardly from the crucible 3, the cooling speed is accelerated, and the backflow of gas between the lower part of the flow guide cylinder structure 6 and the upper part of the liquid surface can be avoided. In addition, the oxygen content concentration in the crystal can be reduced, and the quality of the single crystal silicon rod can be ensured.

[0045] In addition, the gas guide channel 64 can be directly formed in the side wall of the flow guide outer cylinder 62 by integral molding or the like. The manufacturing cost is low, the maintenance of the flow guide cylinder structure 6 is convenient in the later period, the safety risk in the process of installation or disassembly of the gas guide channel 64 can be avoided, and the use safety is improved.

[0046] According to the utility model embodiment, the gas outlet 642 is arranged on the lower part of the flow guide outer cylinder 62 and opens towards the crucible 3, the gas outlet 642 is in communication with the gas guide flow channel 64, and then the inert gas can flow through the gas guide flow channel 64 between the crucible 3 and the lower part of the flow guide cylinder structure 6, so that gas backflow between the lower part of the flow guide cylinder structure 6 and above the liquid surface is avoided, the flow rate of the gas near the solid-liquid interface can be improved, the cooling effect on the single crystal silicon rod crystal growth position is ensured, the oxygen content concentration in the crystal can be reduced, the quality of the single crystal silicon rod is ensured, the setting cost is low, maintenance is facilitated, the use effect is better, and the application range is wider.

[0047] In some embodiments, the gas guide flow channel 64 comprises a gas inlet flow channel and a gas outlet flow channel connected in series, the gas inlet 641 is in communication with the gas inlet flow channel, the gas outlet 642 is in communication with the gas outlet flow channel, and the gas outlet flow channel is configured as an annular flow channel.

[0048] Specifically, the gas guide flow channel 64 is arranged in the side wall of the flow guide outer cylinder 62, the flow guide outer cylinder 62 is provided with the gas inlet 641 and the gas outlet 642 in communication with the gas guide flow channel 64, and the gas guide flow channel 64 comprises a gas inlet flow channel and a gas outlet flow channel, as shown in the figure, the gas inlet flow channel and the gas outlet flow channel are in communication, the gas inlet 641 is in communication with the gas inlet flow channel, that is, one end of the gas inlet flow channel is in communication with the gas inlet 641, and the other end is in communication with the gas outlet flow channel, so that the gas can enter the gas inlet flow channel through the gas inlet 641 to flow to the gas outlet flow channel through the gas inlet flow channel. Figures 1-2

[0049] Further, the gas outlet flow channel is in communication with the gas outlet 642, so that after the gas flows to the gas outlet flow channel, the gas can flow into the crucible 3 through the gas outlet 642, and the gas inlet flow channel can be configured as a straight line flow channel, the gas inlet flow channel extends in the up-down direction, the setting length of the gas inlet flow channel can be shortened, and then the gas flow time in the gas guide flow channel 64 can be reduced to reduce the gas power loss and ensure the gas flow rate, and the gas outlet flow channel can be configured as an annular flow channel, that is, the side wall of the lower part of the flow guide outer cylinder 62 is uniformly provided with the gas outlet flow channel in the circumferential direction, so that after the gas flows to the gas outlet flow channel through the gas inlet flow channel, the gas can flow along the gas outlet flow channel around the circumferential direction of the flow guide outer cylinder 62, so that when the gas outlet 642 is arranged at each part of the circumferential direction of the lower part of the flow guide outer cylinder 62, the gas outlet 642 can be in communication with the gas outlet flow channel, and the setting flexibility is improved.

[0050] In some embodiments, the gas inlet flow channel is provided as at least one, and / or the gas outlet 642 is provided as a plurality of gas outlets, that is, the gas inlet flow channel can be provided as at least one, or the gas outlet 642 can be provided as a plurality of gas outlets, or the gas inlet flow channel can be provided as at least one while the gas outlet 642 is provided as a plurality of gas outlets, and the setting flexibility is improved.

[0051] ​Specifically, the air inlet channels are provided as at least one, i.e. one, two or three, etc. The air inlets 641 are provided corresponding to the air inlet channels. The air inlet channels are in communication with the air outlet channels, so that one or more air inlet channels can deliver gas to the air outlet channels. When the air inlet channels are provided as one, the cavity volume in the side wall of the flow guide outer cylinder 62 can be reduced, and the structural strength of the flow guide outer cylinder 62 can be ensured. When the air inlet channels are provided as multiple, the multiple air inlet channels are in communication with the air outlet channels, so that the multiple air inlet channels can deliver gas to the air outlet channels together, thereby increasing the rate of gas delivered by the air guide channel 64, ensuring the amount and flow rate of gas flowing to the liquid surface, reducing the temperature at the single crystal silicon rod, and reducing the oxygen content in the crystal to ensure the quality of the single crystal silicon rod.

[0052] Further, the air outlet channels are in communication with the air outlets 642, and the air outlets 642 can be provided as multiple, i.e. two, three or four, etc. The multiple air outlets 642 are distributed at intervals in the circumferential direction of the flow guide outer cylinder 62, and the multiple air outlets 642 are in communication with the air outlet channels. The multiple air outlets 642 can be open to the crucible 3, so that the gas flowing to the air outlet channels can flow to the crucible 3 from multiple places in the circumferential direction of the flow guide outer cylinder 62, thereby cooling multiple places of the solid-liquid interface, increasing the cooling speed, ensuring the cooling reliability, and increasing the gas flow rate to reduce the oxygen content in the crystal.

[0053] In addition, the multiple air outlets 642 can be distributed at intervals in the circumferential direction of the flow guide outer cylinder 62, so that the amount of gas flowing to each place of the liquid surface of the crucible 3 is equal, ensuring uniform cooling at each place, and ensuring the same oxygen content at each place of the crystal, thereby improving the quality of the single crystal silicon rod.

[0054] In some embodiments, the air outlets 642 are provided as four, and the four air outlets 642 are in communication with the air outlet channels and distributed at intervals in the circumferential direction of the air outlet channels.

[0055] Specifically, the air outlets 642 are in communication with the air outlet channels, so that the gas in the air outlet channels can flow to the crucible 3 through the air outlets 642. The air outlets 642 can be provided as four, and the four air outlets 642 are in communication with the air outlet channels, so that the gas in the air outlet channels can flow to the crucible 3 through the four air outlets 642 respectively, thereby increasing the gas flow rate at multiple places of the solid-liquid interface to increase the gas flow rate and the cooling speed.

[0056] Further, the four gas outlets 642 are equidistantly distributed along the circumference of the gas outlet flow channel, that is, the four gas outlets 642 are arranged at positions on the annular gas outlet flow channel with an interval of 90°, so that the gas outlet flow channel only needs to be provided with one, and the four gas outlets 642 can be supplied with gas, the sizes of the four gas outlets 642 are all set to be the same, and the four gas outlets 642 are equidistantly distributed along the circumference of the gas outlet flow channel, so that the flow rates and the amounts of the gas flowing through the four gas outlets 642 are all the same, thereby ensuring that the amounts of the gas flowing to all parts of the liquid surface in the crucible 3 are all equal, so as to ensure that the cooling is uniform at all parts, and the oxygen content is the same at all parts of the crystal, thereby improving the quality of the single crystal silicon rod.

[0057] In some embodiments, the flow guide outer cylinder 62 comprises a straight cylinder portion 621 and an arc-shaped cylinder portion 622, the arc-shaped cylinder portion 622 is connected to the lower end of the straight cylinder portion 621, the center of the arc-shaped cylinder portion 622 is located in the flow guide outer cylinder 62, and the gas outlet flow channel is formed in the arc-shaped cylinder portion 622.

[0058] Specifically, the flow guide outer cylinder 62 is arranged outside the flow guide cylinder structure 6, and the flow guide outer cylinder 62 is provided with a straight cylinder portion 621 and an arc-shaped cylinder portion 622, the straight cylinder portion 621 is arranged at the upper part of the flow guide outer cylinder 62 and is arranged in a cylindrical structure, and the arc-shaped cylinder portion 622 is arranged at the lower part of the flow guide outer cylinder 62 and is connected below the straight cylinder portion 621, the center of the arc-shaped cylinder portion 622 can be arranged to be located in the flow guide outer cylinder 62, that is, the arc-shaped cylinder portion 622 bends into the flow guide outer cylinder 62 in the direction from top to bottom, the arc-shaped cylinder portion 622 can be arranged as a quarter circle, the straight line in the vertical direction of the straight cylinder portion 621 is tangent to the arc-shaped cylinder portion 622, and the lower part of the arc-shaped cylinder portion 622 is tangent to the horizontal plane, thereby making the lower part of the arc-shaped cylinder portion 622 parallel to the liquid surface, that is, the distance between the lower part of the arc-shaped cylinder portion 622 and the liquid surface is equal, which can reduce the temperature gradient difference between the center and the edge of the single crystal rod in the radial direction of the solid-liquid interface, thereby ensuring the quality of the single crystal silicon rod.

[0059] Further, the gas outlet flow channel can be formed in the arc-shaped cylinder portion 622, and the gas outlet 642 is also arranged in the arc-shaped cylinder portion 622, as shown in Figure 3 The arc-shaped cylinder portion 622 can be partially arranged in the crucible 3, the gas outlet flow channel is arranged in the arc-shaped cylinder portion 622, so that the gas outlet 642 can be open towards the side of the crucible 3, thereby making the inert gas flow through the gas guide flow channel 64 to the space between the crucible 3 and the arc-shaped cylinder portion 622, avoiding the backflow of the gas between the arc-shaped cylinder portion 622 and the space above the liquid surface, thereby improving the flow rate of the gas near the solid-liquid interface, reducing the oxygen content during the single crystal growth, and reducing the adhesion of the liquid to the arc-shaped cylinder portion 622, avoiding the difference in the detection of the pulling distance of the crystal due to the adhesion of the liquid, affecting the effective output of the single crystal silicon rod, and ensuring the reliability of the output of the single crystal silicon rod.

[0060] In some embodiments, the distance between the connection of the straight cylinder part 621 and the arc-shaped cylinder part 622 and the gas outlet flow channel in the vertical direction is L, and satisfies: 19mm≤L≤21mm.

[0061] Specifically, as shown in Figure 1 and Figure 3 shown, the flow guide outer cylinder 62 is provided with a straight cylinder part 621 and an arc-shaped cylinder part 622 connected in the up-down direction, the arc-shaped cylinder part 622 can be partially placed in the crucible 3, and the distance between the connection of the straight cylinder part 621 and the arc-shaped cylinder part 622 and the gas outlet flow channel in the vertical direction is L, and satisfies: 19mm≤L≤21mm, that is, the distance L between the connection of the straight cylinder part 621 and the arc-shaped cylinder part 622 and the gas outlet flow channel in the vertical direction can be set to 19mm, 20mm or 21mm, etc., and in the embodiment, the distance L between the connection of the straight cylinder part 621 and the arc-shaped cylinder part 622 and the gas outlet flow channel in the vertical direction is set to 20mm.

[0062] Further, the gas outlet flow channel is arranged at the arc-shaped cylinder part 622, and the distance L between the connection of the straight cylinder part 621 and the arc-shaped cylinder part 622 and the gas outlet flow channel in the vertical direction is set to 20mm, so that the gas outlet flow channel can be arranged close to the single crystal silicon rod in the horizontal direction, and the distance between the gas outlet flow channel and the liquid surface in the vertical direction is greater than the distance between the bottom of the arc-shaped cylinder part 622 and the liquid surface, thereby increasing the gas flow speed of the side of the crucible 3, and enabling the gas to be quickly discharged from the gap between the sidewall of the crucible 3 and the arc-shaped cylinder part 622, thereby reducing the oxygen content in the crystal and ensuring the quality of the single crystal silicon rod.

[0063] In some embodiments, the diameter of the gas inlet port 641 is greater than the diameter of the gas guide flow channel 64; and / or, the diameter of the gas inlet port 641 is greater than the diameter of the gas outlet port 642, that is, only the diameter of the gas inlet port 641 can be greater than the diameter of the gas guide flow channel 64, and only the diameter of the gas inlet port 641 can be greater than the diameter of the gas outlet port 642, and the diameter of the gas inlet port 641 can be greater than the diameter of the gas guide flow channel 64 while the diameter of the gas inlet port 641 is greater than the diameter of the gas outlet port 642, thereby improving the flexibility of the arrangement.

[0064] Specifically, as shown in Figure 2As shown, the gas inlet 641 is in communication with the gas guide channel 64 to convey gas into the gas guide channel 64, and the diameter of the gas inlet 641 can be set to be greater than the diameter of the gas guide channel 64, so as to facilitate the external gas conveying pipeline to convey gas into the gas guide channel 64, and the diameter of the gas inlet 641 is set to be relatively large, so that the amount of gas at the gas inlet 641 is relatively large, and the diameter of the gas guide channel 64 is set to be relatively small, so that the flow rate of the gas flowing into the gas guide channel 64 is accelerated, thereby ensuring the flow rate of the gas flowing into the crucible 3, so as to improve the gas flow rate at the solid-liquid interface, reduce the oxygen content in the crystal, and ensure the quality of the single crystal silicon rod.

[0065] Further, the gas guide channel 64 is in communication with the gas inlet 641 and the gas outlet 642, respectively, and the gas can flow into the gas guide channel 64 through the gas inlet 641, and then flow into the gas outlet 642 through the gas guide channel 64. The diameter of the gas inlet 641 is set to be greater than the diameter of the gas outlet 642, that is, the diameter of the gas inlet 641 is set to be relatively large, and the diameter of the gas outlet 642 is set to be relatively small. The gas outlet 642 can be provided in a plurality of forms, and the gas inlet 641 is provided in one form. The diameter of the gas inlet 641 is set to be relatively large, so as to ensure the amount of conveyed gas, and the diameter of the gas outlet 642 is set to be relatively small, so as to ensure the amount of gas conveyed to each gas outlet 642, and to improve the flow rate of the gas output from the gas outlet 642, thereby ensuring the flow rate of the gas at the solid-liquid interface, so as to improve the cooling rate and reduce the oxygen content.

[0066] In some embodiments, the diameter of the gas inlet 641 is set to r1, and satisfies: 9mm≤r1≤11mm.

[0067] Specifically, the gas inlet 641 is provided on the gas guide outer cylinder 62, and can be arranged at the upper portion or the top of the gas guide outer cylinder 62, so as to facilitate the external gas conveying pipeline to be in communication with the gas inlet 641. The diameter of the gas inlet 641 is set to r1, and satisfies: 9mm≤r1≤11mm, that is, the diameter r1 of the gas inlet 641 can be set to 9mm, 10mm or 11mm, etc. In the present embodiment, the diameter r1 of the gas inlet 641 is set to 10mm. The diameter r1 of the gas inlet 641 is set to satisfy: 9mm≤r1≤11mm, so that the diameter of the gas inlet 641 is relatively large, thereby increasing the amount of gas at the gas inlet 641, ensuring sufficient amount of conveyed gas, and setting the diameter of the gas inlet 641 to be relatively large facilitates the connection with the external gas conveying pipeline, and improves the installation convenience.

[0068] In other embodiments, the diameter of the gas guide channel 64 is set to r2, and satisfies: 4mm≤r2≤6mm.

[0069] Specifically, the side wall of the flow guide outer cylinder 62 is provided with a gas guide channel 64, the gas inlet 641 is communicated with the gas guide channel 64 to convey gas into the gas guide channel 64, the diameter of the gas guide channel 64 is set as r2, and satisfies: 4mm≤r2≤6mm, that is, the diameter r2 of the gas guide channel 64 can be set as 4mm, 5mm or 6mm, etc., in this embodiment, the diameter r2 of the gas guide channel 64 is set as 5mm, and the diameter r2 of the gas guide channel 64 is set to satisfy: 4mm≤r2≤6mm, so that the diameter of the gas guide channel 64 is small, and then the gas flow rate at the gas inlet 641 into the gas guide channel 64 can be increased, and then the gas flow rate flowing to the solid-liquid interface can be increased, the oxygen content of the single crystal silicon rod is reduced, and the quality of the single crystal silicon is ensured.

[0070] In other embodiments, the diameter of the gas outlet 642 is set as r3, and satisfies: 4mm≤r3≤6mm.

[0071] Specifically, the lower part of the flow guide outer cylinder 62 is provided with a gas outlet 642, the gas outlet 642 is communicated with the gas guide channel 64, so that the gas in the gas guide channel 64 can convey gas into the crucible 3 through the gas outlet 642, and the diameter of the gas outlet 642 is set as r3, and satisfies: 4mm≤r3≤6mm, that is, the diameter r3 of the gas outlet 642 can be set as 4mm, 5mm or 6mm, etc., in this embodiment, the diameter r3 of the gas outlet 642 is set as 5mm, and the diameter r3 of the gas outlet 642 is set to satisfy: 4mm≤r3≤6mm, so that the diameter of the gas outlet 642 is small, and then the gas flow rate of the gas outlet 642 can be ensured, so that the gas flow rate flowing to the solid-liquid interface can be ensured, the oxygen content of the single crystal silicon rod is reduced, and the quality of the single crystal silicon is ensured.

[0072] In some embodiments, the included angle between the opening direction of the gas outlet 642 and the horizontal plane is set as a, and satisfies: 25°≤a≤35°.

[0073] Specifically, the gas outlet 642 is arranged on the arc-shaped cylinder part 622 of the flow guide outer cylinder 62, and is open towards the side of the crucible 3, so that the gas can flow to the solid-liquid interface through the gas outlet 642 to increase the gas flow rate at the liquid surface, reduce the oxygen content of the single crystal silicon rod, and the included angle between the opening direction of the gas outlet 642 and the horizontal plane is set as a, and satisfies: 25°≤a≤35°, that is, the included angle a between the opening direction of the gas outlet 642 and the horizontal plane can be set as 25°, 30° or 35°, etc., and the gas outlet 642 is arranged on the outer wall of the bottom of the flow guide cylinder structure 6 and is open outward.

[0074] Therefore, the included angle a between the opening direction of the gas outlet 642 and the horizontal plane is set to satisfy 25°≤a≤35°, so that the opening direction of the gas outlet 642 is inclined, and the gas outlet 642 can be opened towards the direction of the liquid surface close to the side wall of the crucible 3, the resistance of the gas flowing out of the gas outlet 642 can be reduced, the speed of the gas above the liquid surface flowing out to the gap between the side wall of the crucible 3 and the arc-shaped cylinder part 622 can be accelerated, and the oxygen content in the single crystal silicon rod can be reduced, so as to ensure the quality of the single crystal silicon.

[0075] In other embodiments, the inner peripheral wall of the gas guide channel 64 is provided with a flow guide film, which can be made of molybdenum or the like, and can increase the smoothness of the inner wall of the gas guide channel 64, thereby reducing the frictional resistance of the gas flowing in the gas guide channel 64, so as to reduce the flow loss and ensure the gas flow rate.

[0076] The utility model discloses still provide a kind of single crystal furnace 100.

[0077] According to the single crystal furnace 100 of the utility model embodiment, the heat preservation barrel 2, the crucible 3 and the flow guide cylinder structure 6 of any one of the above are included, the crucible 3 and the flow guide cylinder structure 6 are both installed in the heat preservation barrel 2, and at least part of the flow guide cylinder structure 6 is placed in the crucible 3.

[0078] Specifically, the outermost side of the single crystal furnace 100 is provided with a furnace barrel 1, and the reaction process of the single crystal furnace 100 is completed in the furnace barrel 1. The furnace barrel 1 is provided with a heat preservation barrel 2, and the crucible 3 and the flow guide cylinder structure 6 are both installed in the heat preservation barrel 2. The flow guide cylinder structure 6 is arranged above the crucible 3, and at least part of the bottom of the flow guide cylinder structure 6 is placed in the crucible 3, so that the flow guide cylinder structure 6 can deliver gas into the crucible 3. The heat preservation barrel 2 is provided with a detachable heat preservation cover 21 and a heat preservation barrel main body 22, which facilitates installation. The crucible 3 can be installed on a crucible support 31, and a drag link 32 can support the crucible 3. The side wall and the bottom of the crucible 3 are respectively provided with a first heater 4 and a second heater 5. The first heater 4 is a main heater, and the second heater 5 is a bottom heater, which can ensure stable reaction process. The furnace barrel 1 is further provided with a furnace bottom heat preservation 11 below, to ensure the reliability of the reaction.

[0079] The complete production steps of the single crystal silicon rod are as follows: high-purity polycrystalline silicon raw material is put into the high-purity quartz crucible 3, and the high-temperature generated by the first heater 4 and the second heater 5 is used to melt the high-purity polycrystalline silicon raw material; then, the molten silicon liquid is slightly cooled to generate a certain degree of supercooling, and a single crystal silicon body (called a seed crystal) fixed on a seed crystal shaft is inserted into the surface of the melt; after the seed crystal is melted with the melt, the seed crystal is slowly pulled upwards, and the crystal grows at the lower end of the seed crystal; then, the seed crystal is controlled to grow a thin neck, which is used to eliminate the dislocation of atomic arrangement caused by the strong thermal shock of the high-temperature solution to the seed crystal, and this process is called crystal pulling; subsequently, the diameter of the crystal is enlarged to the size required by the process, and this process is called shoulder enlargement; then, the pulling speed is suddenly increased to perform a shoulder turning operation, so that the shoulder is approximately at right angles; then, the equal-diameter process is entered, and a single crystal column with a certain diameter specification is grown by controlling the temperature of the heat field and the lifting speed of the crystal; finally, when most of the silicon solution has completed crystallization, the crystal is gradually reduced to form a tail-shaped taper, which is called a tailing process. Thus, the single crystal pulling process is basically completed, and the crystal can be taken out after a certain heat preservation and cooling.

[0080] According to the single crystal furnace 100, the gas outlet 642 is arranged at the lower part of the flow guide outer cylinder 62 and opens towards the crucible 3, the gas outlet 642 is in communication with the gas guide channel 64, and thus the inert gas can flow through the gas guide channel 64 to the lower part between the crucible 3 and the flow guide cylinder structure 6, so that the gas backflow between the lower part of the flow guide cylinder structure 6 and the upper part of the liquid surface is avoided, the flow rate of the gas near the solid-liquid interface is improved, the cooling effect on the crystal growth position of the single crystal silicon rod is ensured, the oxygen content concentration in the crystal is reduced, the quality of the single crystal silicon rod is ensured, the setting cost is low, maintenance is facilitated, the use effect is better, and the application range is wider.

[0081] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0082] Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and purposes of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A shroud structure for a single crystal furnace, characterized by comprising: The flow guide structure is suitable for being installed above a crucible of the single crystal furnace, and the flow guide structure comprises: a flow guide inner cylinder and a flow guide outer cylinder, the flow guide inner cylinder is installed in the flow guide outer cylinder, and a heat insulation space is formed between the flow guide inner cylinder and the flow guide outer cylinder; a gas flow guide channel is formed in a side wall of the flow guide outer cylinder, the flow guide outer cylinder is formed with a gas inlet and a gas outlet which communicate with the gas flow guide channel, and the gas outlet is arranged at a lower part of the flow guide outer cylinder and opens towards the crucible.

2. The draft tube structure for a single crystal furnace according to claim 1, wherein The gas flow guide channel comprises a gas inlet channel and a gas outlet channel which are connected, the gas inlet communicates with the gas inlet channel, the gas outlet communicates with the gas outlet channel, and the gas outlet channel is configured as an annular channel.

3. The draft tube structure for a single crystal furnace according to claim 2, wherein The gas inlet channel is at least one; and / or, the gas outlet is multiple, and the multiple gas outlets all communicate with the gas outlet channel.

4. The draft tube structure for a single crystal furnace according to claim 2, wherein The gas outlet is four, the four gas outlets all communicate with the gas outlet channel and are distributed equidistantly along a circumference of the gas outlet channel.

5. The draft tube structure for a single crystal furnace according to claim 2, wherein The flow guide outer cylinder comprises a straight cylinder part and an arc-shaped cylinder part, the arc-shaped cylinder part is connected to a lower end of the straight cylinder part, a center of the arc-shaped cylinder part is located in the flow guide outer cylinder, and the gas outlet channel is formed in the arc-shaped cylinder part.

6. The draft tube structure for a single crystal furnace according to claim 5, wherein A distance between the straight cylinder part and the arc-shaped cylinder part along a vertical direction and the gas outlet channel is L, and satisfies: 19mm≤L≤21mm.

7. The draft tube structure for a single crystal furnace according to claim 1, wherein A diameter of the gas inlet channel is greater than a diameter of the gas flow guide channel; and / or, a diameter of the gas inlet is greater than a diameter of the gas outlet.

8. The draft tube structure for a single crystal furnace according to claim 1, wherein The diameter of the gas inlet is r1, and satisfies: 9mm≤r1≤11mm; and / or, the diameter of the gas flow guide channel is r2, and satisfies: 4mm≤r2≤6mm; and / or, the diameter of the gas outlet is r3, and satisfies: 4mm≤r3≤6mm.

9. The draft tube structure for a single crystal furnace according to claim 1, wherein An included angle between an opening direction of the gas outlet and a horizontal plane is a, and satisfies: 25°≤a≤35°; and / or, an inner circumferential wall of the gas flow guide channel is provided with a flow guide film.

10. A single crystal furnace characterized by comprising: The single crystal furnace comprises a heat preservation barrel, a crucible and the flow guide structure according to any one of claims 1-9, the crucible and the flow guide structure are both installed in the heat preservation barrel, and at least part of the flow guide structure is arranged in the crucible.

Images