Water-cooled screen and single crystal furnace for pulling rate and oxygen reduction in single crystal production

Abstract

The utility model relates to a water cooling screen and single crystal furnace for pulling speed and oxygen reduction in single crystal production, the utility model provides a water cooling screen for pulling speed and oxygen reduction in single crystal production, include: cylinder, the cylinder has the hollow silicon rod crystal containing space, the bottom of cylinder includes first plane and first side, wherein, first side surrounds first plane and sets up, first side includes first end and second end, first end is connected with first plane, second end extends to the direction of away from the central axis of cylinder, first end has first height, second end has second height, and first height is less than second height, wherein, first side and first plane have first included angle between, and first included angle is 0 degree 20 degrees, first pipe, first pipe includes liquid inlet line and liquid outlet line, is used for cooling silicon rod crystal containing space, and second pipe is used for inputting gas to reduce oxygen content.

Description

Technical Field

[0001] This utility model relates to the field of monocrystalline silicon pulling technology, specifically to a water-cooled screen and monocrystalline furnace used for increasing pulling speed and reducing oxygen in monocrystalline production. Background Technology

[0002] Competition in the photovoltaic industry is becoming increasingly fierce. "Increasing production and speed" and "reducing costs and increasing efficiency" are the core development concepts of every monocrystalline manufacturing company. Every link in monocrystalline production strictly controls working hours and efficiency, and pursues the ultimate.

[0003] The growth rate of crystals depends on factors such as the cooling rate at the interface between the silicon rod and the molten silicon surface, and the crystal lifting speed. The quality of the crystal is closely related to the oxygen content during the lifting process; if the silicon surface is oxidized, an impurity layer will form inside the crystal, affecting its electrical properties. However, current technologies still face the challenge of improving both the heat exchange efficiency and oxygen reduction effectiveness of water-cooled screens. Utility Model Content

[0004] To address the aforementioned technical problems, this application provides a water-cooled screen for increasing pulling speed and reducing oxygen in single crystal production, thereby improving the heat exchange and oxygen reduction effects of the water-cooled screen.

[0005] The present invention provides a water-cooled screen for increasing pulling speed and reducing oxygen in single crystal production, comprising: a cylindrical body having a hollow silicon rod crystal accommodating space; the bottom of the cylindrical body including a first plane and a first side surface, wherein the first side surface is arranged around the first plane, the first side surface including a first end and a second end, the first end being connected to the first plane, the second end extending in a direction away from the central axis of the cylindrical body, the first end having a first height, the second end having a second height, the first height being less than the second height, wherein there is a first included angle between the first side surface and the first plane, the first included angle being 0 degrees to 20 degrees; a first pipe including a liquid inlet pipe and a liquid outlet pipe for cooling the silicon rod crystal accommodating space; and a second pipe for inputting gas to reduce the oxygen content.

[0006] In one embodiment of the present invention, the cylinder includes a first cavity, which is arranged around the central axis of the cylinder. The first cavity includes an inlet end and an outlet end, wherein the inlet end is connected to the inlet pipe to allow liquid to enter the first cavity, and the outlet end is connected to the outlet pipe to allow the liquid to flow out of the first cavity.

[0007] In one embodiment of the present invention, the cylinder further includes a second cavity, which is arranged around the central axis of the cylinder and is adjacent to the inner side of the first cavity; wherein, the inner side of the first cavity is further provided with a sandwich layer, the sandwich layer having an air inlet end and an air outlet end, the air inlet end being connected to the second pipe, and the air outlet end being connected to the second cavity, so that the gas enters the second cavity.

[0008] In one embodiment of the present invention, the first pipe and the second pipe are composed of a single pipe body, the pipe body having an isolation device inside, the isolation device dividing the pipe body into the first pipe and the second pipe.

[0009] In one embodiment of this invention, the gas includes argon.

[0010] In one embodiment of the present invention, at least a portion of the first pipe and at least a portion of the second pipe are disposed above the cylinder.

[0011] In one embodiment of the present invention, the second cavity includes a cavity wall facing the silicon rod crystal receiving space, and the cavity wall includes a plurality of exhaust holes to allow the gas to be discharged into the silicon rod crystal receiving space.

[0012] In one embodiment of this utility model, the height of the cavity wall is 150mm-160mm, and the distance between any two exhaust holes is 25mm.

[0013] In one embodiment of the present invention, each of the plurality of vent holes has a first length along a first direction, the first direction has a second angle with the silicon liquid plane, and the first direction has a third angle with the axial direction of the silicon rod crystal, wherein the second angle and the third angle are both 45°.

[0014] To solve the above-mentioned technical problems, this application also provides a single crystal furnace, including: a crucible configured to contain and heat molten silicon; and a water-cooled screen as described above, configured to be disposed along the axial direction of the silicon rod crystal.

[0015] This application, by setting the first side of the cylinder around the first plane and setting the first included angle between the first side and the first plane to 0-20 degrees, compresses the space between the silicon rod liquid surface and the water-cooled screen during crystal pulling, accelerates the gas flow rate and changes the airflow direction, thereby improving the oxygen reduction and heat exchange effects of the water-cooled screen. Attached Figure Description

[0016] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings, wherein:

[0017] Figure 1 This is a cross-sectional view of a water-cooled screen according to an embodiment of this application;

[0018] Figure 2 yes Figure 1 An enlarged schematic diagram of region A of the water-cooled screen in the illustrated embodiment;

[0019] Figure 3 yes Figure 1 An enlarged schematic diagram of region B of the water-cooled screen in the illustrated embodiment;

[0020] Figure 4 yes Figure 1 An enlarged schematic diagram of region C of the water-cooled screen in the embodiment shown;

[0021] Figure 5 yes Figure 1 A cross-sectional view of the second cavity of the water-cooled screen in the embodiment shown. Detailed Implementation

[0022] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0023] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein, and therefore the present invention is not limited to the specific embodiments disclosed below.

[0024] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" are not specifically singular and may include plural forms. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0025] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0026] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application. In addition, although the terminology used in this application is selected from commonly known and used terms, some terms mentioned in this application's specification may have been chosen by the applicant according to his or her judgment, and their detailed meanings are explained in the relevant sections of this description. Moreover, this application should be understood not only through the actual terms used, but also through the meaning implied by each term.

[0027] The embodiments of the present invention will now be described based on the accompanying drawings. However, the embodiments shown below are examples of water-cooled screens and single-crystal furnaces used to embody the technical concept of the present invention, and the water-cooled screens and single-crystal furnaces of the present invention are not specifically defined as described below. Furthermore, in order to facilitate understanding of the scope of the claims, the components corresponding to those shown in the embodiments are assigned numbers to the components shown in the "Claims" and "Summary of the Utility Model" columns. However, this is by no means to specify the components shown in the claims as components of the embodiments. In particular, the dimensions, materials, shapes, and relative arrangements of the constituent components described in the embodiments, unless specifically stated, are not intended to limit the scope of the present invention to these aspects, but are merely illustrative examples.

[0028] However, the dimensions or positional relationships of the components shown in the accompanying drawings are sometimes exaggerated for clarity. Therefore, in the following description, detailed descriptions of the same names and symbols representing the same or homogeneous components are appropriately omitted. Furthermore, the elements constituting this utility model can be multiple elements composed of the same components, thus allowing one component to function as multiple elements; conversely, multiple components can share the function of one component. Additionally, the content described in some embodiments and implementations can be applied to other embodiments and implementations. Furthermore, in this specification, "upper" is not limited to the case of being formed in contact with an upper surface, but also includes the case of being formed separately on top, and also includes the meaning of an interlayer between layers.

[0029] Existing water-cooled screens typically increase heat exchange area by improving the structure of the inner wall, adding numerous recesses to enhance the cooling rate of the silicon ingot and the interface between the silicon ingot and the molten silicon, thereby increasing pulling speed and production output. However, this approach still faces the challenge of improving both the heat exchange efficiency and oxygen reduction effect of the water-cooled screen. This application addresses this issue by improving the structure of the water-cooled screen, thereby enhancing both heat exchange and oxygen reduction effects.

[0030] Figure 1A cross-sectional view of a water-cooled screen according to an embodiment of this application is shown. Figure 2 It shows Figure 1 An enlarged schematic diagram of region A of the water-cooled screen in the illustrated embodiment. (See diagram below.) Figure 1 and Figure 2 As shown, this application proposes a water-cooled screen 100 for increasing pulling speed and reducing oxygen in single crystal production, comprising: a cylindrical body 10 having a hollow silicon rod crystal receiving space 11; the bottom of the cylindrical body 10 includes a first plane 12 and a first side 13, wherein the first side 13 is arranged around the first plane 12, and the first side 13 includes a first end 13a and a second end 13b; the first end 13a is connected to the first plane 12, and the second end 13b extends in the F direction away from the central axis 14 of the cylindrical body 10; the first end 13a has a first height, and the second end 13b has a second height h2, the first height being less than the second height h2; wherein there is a first included angle θ1 between the first side 13 and the first plane 12, the first included angle θ1 being 0 degrees to 20 degrees; a first pipe 15 including a liquid inlet pipe 151 and a liquid outlet pipe 152 for cooling the silicon rod crystal receiving space 11; and a second pipe 16 for inputting gas to reduce the oxygen content.

[0031] This application sets the first side surface 13 of the cylinder 10 around the first plane 12 and sets the first included angle θ1 between the first side surface 13 and the first plane 12 to 0 degrees-20 degrees. This compresses the second space 210 between the liquid surface 200 of the silicon liquid during crystal pulling and the water-cooled screen 100, accelerates the gas flow rate and changes the gas flow direction, and further improves the oxygen reduction and heat exchange effect of the water-cooled screen 100.

[0032] like Figure 1 As shown, the cylinder 10 is an axisymmetric structure with the central axis 14 as the axis of symmetry. The silicon rod crystal accommodating space 11 formed inside the cylinder 10 is used to accommodate the silicon rod crystal, so as to facilitate the lifting of the silicon rod crystal in the silicon melt.

[0033] In some embodiments, the first plane 12 is circular, with its center at the geometric center of the bottom of the cylinder 10. The first side surface 13 is disposed around the center of the first plane 12, which is a point on the central axis 14. In some embodiments, the first plane 12 and the first side surface 13 can also be adaptively adjusted to other shapes according to actual needs.

[0034] In some embodiments, since the first end 13a of the first side 13 is connected to the first plane 12, with the first plane 12 as a reference, the first height is 0. For example... Figure 1 and Figure 2As shown, the second end 13b of the first side 13 extends along the F direction away from the central axis 14. With the first plane 12 as a reference, the second end 13b has a second height h2. If the second height h2 is greater than 0, then the first height is less than the second height h2. In some embodiments, the specific height of the second height h2 can be set according to actual usage requirements, and this application does not limit it in this way.

[0035] In some embodiments, when the water-cooled screen 100 is in use, the first plane 12 and the first side 13 are close to the molten silicon, and the first plane 12 is parallel to the liquid surface 200. At this time, the first included angle θ1 between the first side 13 and the first plane 12 is equal to the included angle between the first side 13 and the liquid surface 200. In the prior art, the angle θ1 is often greater than 30 degrees. Compared with the prior art, the angle θ1 of this application is smaller. When the angle θ1 is reduced, the volume of the second space 210 between the molten silicon and the water-cooled screen 100 is further compressed. When the silicon rod crystal is stretched in the water-cooled screen 100, the gas flow rate from the second pipe 16 in the cylinder 10 becomes faster. At this time, the gas can carry away more oxygen and heat, thereby improving the oxygen reduction and cooling effect of the water-cooled screen. Preferably, the first included angle θ1 of this application is 15 degrees.

[0036] Figure 3 It shows Figure 1 An enlarged schematic diagram of region B of the water-cooled screen in the illustrated embodiment. (See diagram below.) Figure 1 and Figure 3 As shown, in some embodiments, the first pipe 15 and the second pipe 16 are constituted by a single pipe body 30, which has an internal isolation device 31 that divides the pipe body 30 into the first pipe 15 and the second pipe 16. By constituting the first pipe 15 and the second pipe 16 into a single pipe body 30, the ease of pipe installation is improved. In some embodiments, the first pipe 15 and the second pipe 16 can also be configured as two independent pipes.

[0037] In some embodiments, the isolation device 31 comprises a relatively stable material such as stainless steel.

[0038] In some embodiments, the liquid transported via the first pipe 15 is water, which can be circulated for cooling via the inlet pipe 151 and the outlet pipe 152. In some embodiments, the liquid used in the first pipe 15 may also be other liquids with cooling effects.

[0039] In some embodiments, the gas includes argon. In some embodiments, the gas introduced via the second conduit 16 also includes nitrogen or other inert gases.

[0040] like Figure 1As shown, in some embodiments, at least a portion of the first pipe 15 and at least a portion of the second pipe 16 are disposed above the cylinder 10. By disposing at least a portion of the first pipe 15 and at least a portion of the second pipe 16 above the cylinder 10, the first pipe 15 and the second pipe 16 are easily connected to gas and liquid storage or transmission devices outside the cylinder 10.

[0041] like Figure 1 As shown, in some embodiments, the cylinder 10 further includes a first cavity 17, which is arranged around the central axis 14 of the cylinder 10. The first cavity 17 includes a liquid inlet 171 and a liquid outlet 172. The liquid inlet 171 is connected to a liquid inlet pipe 151 to allow liquid to enter the first cavity 17, and the liquid outlet 172 is connected to a liquid outlet pipe 152 to allow liquid to flow out of the first cavity 17. By arranging the first cavity 17 around the cylinder 10, the silicon rod crystal receiving space 11 can be cooled uniformly.

[0042] like Figure 1 As shown, in some embodiments, the first cavity 17 includes a first cavity structure 173. This first cavity structure 173 includes a plurality of interconnected small spaces, which effectively increases the length of the liquid flow path, extending the time the liquid remains in the first cavity 17 to adequately cool the silicon rod crystal housing space 11. In some embodiments, the first cavity structure 173 is a grid-like structure. In some embodiments, the material of the first cavity 17 includes molybdenum and its alloys to give the first cavity 17 high corrosion resistance and heat resistance, extending its service life.

[0043] Figure 4 It shows Figure 1 An enlarged schematic diagram of region C of the water-cooled screen in the embodiment shown.

[0044] like Figure 1 and 4 As shown, in some embodiments, the cylinder 10 further includes a second cavity 18, which is arranged around the central axis 14 of the cylinder 10 and is adjacent to the inner side of the first cavity 17. The inner side of the first cavity 17 is further provided with a sandwich 19, which has an inlet end and an outlet end. The inlet end is connected to the second pipe 16, and the outlet end is connected to the second cavity 18, allowing gas to enter the second cavity 18. The sandwich 19 allows gas from the second pipe 16 to smoothly enter the second cavity 18.

[0045] In some embodiments, the inner side of the first cavity 17 refers to the side of the first cavity 17 closer to the central axis 14.

[0046] Figure 5 It shows Figure 1 A cross-sectional view of the second cavity of the water-cooled screen in the embodiment shown.

[0047] like Figure 5 As shown, in some embodiments, the second cavity 18 includes a cavity wall 181 facing the silicon rod crystal receiving space 11. The cavity wall 181 includes a plurality of vent holes 1811 to allow gas to be discharged into the silicon rod crystal receiving space 11. By providing vent holes 1811, when gas is discharged into the silicon rod crystal receiving space 11, oxygen, oxides, and heat on the surface of the silicon rod crystal can be carried away, thereby improving the cooling effect and oxygen reduction effect of the water-cooled screen 100.

[0048] In some embodiments, the cavity wall 181 has a certain thickness to facilitate the provision of an exhaust port. In some embodiments, the length of the exhaust port can be set according to actual needs.

[0049] In some embodiments, the height of the cavity wall is 150mm-160mm, and the spacing between any two exhaust holes 1811 is 25mm. By setting the height of the cavity wall to 150mm-160mm, more exhaust holes can be provided on the cavity wall, further improving the exhaust and oxygen reduction effect. Setting the spacing between any two exhaust holes to 25mm makes the gas discharge in the silicon rod crystal containing space 11 more uniform, thereby ensuring that oxygen and heat on the surface of the silicon rod crystal are uniformly removed.

[0050] like Figure 5 As shown, in some embodiments, each of the plurality of vent holes 1811 has a first length along a first direction F1, the first direction F1 being perpendicular to the silicon liquid plane (and perpendicular to the silicon liquid plane). Figure 5 The first direction F1 and the axis 21 of the silicon rod crystal have a second included angle θ2, and the second included angle θ2 and the third included angle θ3 have a third included angle θ3, which are 45°. When the second included angle θ2 and the third included angle θ3 are set to 45°, when the gas discharged from the exhaust port 1811 blows onto the surface of the silicon rod crystal, it encounters the resistance of the silicon rod crystal and is divided into gas in the direction parallel to the axis of the silicon rod crystal and gas in the direction perpendicular to the axis of the silicon rod crystal. The gas flow velocity in both directions will increase and the gas flow velocity in the two directions will be similar, thereby improving the oxygen reduction and cooling effect of the water-cooled screen 100.

[0051] In some embodiments, the axial direction 21 of the silicon rod crystal is parallel to the central axis axial direction 14, the silicon liquid plane is perpendicular to the axial direction of the silicon rod crystal, and the second included angle θ2 and the third included angle θ3 are complementary angles. When the second included angle θ2 is 45°, the third included angle θ3 is also 45°.

[0052] This application also proposes a single crystal furnace, comprising: a crucible configured to contain and heat molten silicon; and a water-cooled screen 100 as described above, configured to be arranged along the axial direction of the silicon rod crystal. When the crucible heats the molten silicon, the silicon rod crystal is pulled along its axial direction. On the one hand, when the gas discharged from the exhaust port 1811 is blown onto the surface of the silicon rod crystal, it encounters resistance and splits into gas in a direction parallel to the axial direction of the silicon rod crystal and gas in a direction perpendicular to the axial direction of the silicon rod crystal, thus accelerating the gas flow rate. On the other hand, by setting the included angle between the first side surface 13 and the first plane 12 of the water-cooled screen 100 to 0-20 degrees, the volume of the second space is further compressed, further accelerating the gas flow rate, and thus further accelerating the speed at which oxygen and heat are removed from the surface of the silicon rod crystal.

[0053] This application improves the ease of pipe installation by combining the first pipe 15 and the second pipe 16 into a single pipe body 30. Furthermore, by incorporating the first pipe 15 and the second pipe 16, and setting uniformly distributed exhaust holes 1811 on the cavity wall 181, and setting the second included angle θ2 and the third included angle θ3 to 45°, this accelerates gas flow, carrying away more heat and oxygen, thus speeding up the crystallization of the silicon rod and increasing the pulling speed, thereby enhancing production capacity. By setting the first included angle θ1 between the first side surface 13 and the first plane 12 to 0-20 degrees, this application compresses the second space 210 between the liquid surface 200 of the silicon melt and the water-cooled screen 100 during crystal pulling, accelerating the gas flow rate and changing the gas flow direction. This effectively suppresses oxide volatilization into the silicon rod crystal, more quickly removing heat from the surface of the silicon rod crystal, further improving the oxygen reduction and cooling effect of the water-cooled screen 100, and increasing production capacity.

[0054] While the foregoing disclosure has discussed various examples of utility model embodiments that are currently considered useful, it should be understood that such details are for illustrative purposes only, and the appended claims are not limited to the disclosed embodiments. Rather, the claims are intended to cover all modifications and equivalent combinations that conform to the spirit and scope of the present utility model embodiments. For example, although the system components described above can be implemented by hardware devices, they can also be implemented solely by software solutions, such as installing the described system on existing servers or mobile devices.

[0055] Similarly, it should be noted that, in order to simplify the description of this utility model and thus aid in the understanding of one or more embodiments, the foregoing description of the embodiments of this utility model sometimes combines multiple features into a single embodiment, drawing, or description thereof. However, this disclosure method does not imply that the object of this utility model requires more features than those mentioned in the claims. In fact, the embodiments have fewer features than all the features of the single embodiment disclosed above.

[0056] In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of embodiments are modified in some examples with the terms "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may be changed according to the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit reservation. Although the numerical ranges and parameters used to confirm their breadth of range in some embodiments of this invention are approximate values, in specific embodiments, such values ​​are set as precisely as feasible.

Claims

1. A water-cooled screen for pulling rate and oxygen reduction in single crystal production, characterized in that, include: A cylindrical body having a hollow space for accommodating silicon rod crystals, the bottom of the cylindrical body including a first plane and a first side surface, wherein the first side surface is arranged around the first plane, the first side surface including a first end and a second end, the first end being connected to the first plane, the second end extending in a direction away from the central axis of the cylindrical body, the first end having a first height, the second end having a second height, the first height being less than the second height, wherein there is a first included angle between the first side surface and the first plane, the first included angle being 0 degrees to 20 degrees; A first conduit, comprising an inlet conduit and an outlet conduit, is used to cool the space containing the silicon rod crystal; and The second pipe is used to introduce gas to reduce the oxygen content.

2. The water cooled panel of claim 1 wherein, The cylinder includes a first cavity arranged around the central axis of the cylinder. The first cavity includes an inlet end and an outlet end, wherein the inlet end is connected to the inlet pipe to allow liquid to enter the first cavity, and the outlet end is connected to the outlet pipe to allow the liquid to flow out of the first cavity.

3. The water cooled panel of claim 2 wherein, The cylinder further includes a second cavity, which is arranged around the central axis of the cylinder and is adjacent to the inner side of the first cavity; The first cavity is further provided with an interlayer on its inner side. The interlayer has an air inlet and an air outlet. The air inlet is connected to the second pipe, and the air outlet is connected to the second cavity, so that the gas can enter the second cavity.

4. The water cooled panel of claim 1 wherein, The first pipe and the second pipe are composed of a single pipe body, which has an internal isolation device that divides the pipe body into the first pipe and the second pipe.

5. The water cooled panel of claim 1 wherein, The gas includes argon.

6. The water cooled panel of claim 1 wherein, At least a portion of the first pipe and at least a portion of the second pipe are disposed above the cylinder.

7. The water cooled panel of claim 3 wherein, The second cavity includes a cavity wall facing the silicon rod crystal receiving space, and the cavity wall includes a plurality of vent holes to allow the gas to be discharged into the silicon rod crystal receiving space.

8. The water cooled panel of claim 7 wherein, The height of the cavity wall is 150mm-160mm, and the distance between any two exhaust holes is 25mm.

9. The water cooled panel of claim 7 wherein, Each of the plurality of vent holes has a first length along a first direction, the first direction has a second angle with the silicon liquid plane, and the first direction has a third angle with the axial direction of the silicon rod crystal, the second angle and the third angle being 45°.

10. A single crystal furnace characterized by comprising: include: The crucible is configured to contain and heat molten silicon; The water-cooled screen as described in any one of claims 1 to 9 is configured to be disposed along the axial direction of the silicon rod crystal.

Images