Suction and exhaust device for continuous silicon ingot grower

Abstract

The present invention discloses an air intake and exhaust device for a silicon ingot continuous grower. The air intake and exhaust device for a silicon ingot continuous grower of the present invention may include: a chamber, divided into a first area and a second area, wherein the interior of the first area maintains a vacuum atmosphere, a main crucible is arranged at the center for growing the ingot, and a preliminary melter for supplying molten silicon to the main crucible is arranged outside the upper end of the second area; and a vacuum pump is connected to the chamber to provide vacuum pressure in a manner that the interior of the chamber maintains a vacuum atmosphere, a first injection port for inert gas for removing oxides and impurities in the chamber and a first exhaust port for exhausting gas may be arranged in the first area of ​​the chamber, and a second injection port for inert gas for inert gas and a second exhaust port for exhausting gas may be arranged in the second area of ​​the chamber.

Description

Technical Field

[0001] The present invention relates to an ingot growing device for continuously growing silicon ingots, and more particularly to an exhaust and intake device of a silicon ingot continuous growing device for removing oxides and impurities. Background Art

[0002] Typically, a growth furnace (Grower) using the Czochralski method will be installed inside a chamber, and a silicon ingot will be grown in a vacuum atmosphere inside the chamber. In the continuous single crystal silicon growth method based on the Czochralski method, a continuous growth Czochralski method (CCz) structure for supplying solid polysilicon (Polysilicon) is provided, which is upgraded from the initial method. This structure adopts a method of continuously supplying silicon to the crucible. Instead of this continuous growth Czochralski method structure for supplying solid polysilicon, a liquid feeding device has been developed that melts solid polysilicon into a liquid state in a pre-melter and supplies it to a quartz crucible in the center. Therefore, it is necessary to develop an exhaust system for such a device.

[0003] In the prior art related to the continuous growth Czochralski method, the vacuum atmospheres of the pre-melter and the main chamber are not connected. In the system in a vacuum state, in order to facilitate the extraction of impurities, the pressure of the pre-melter is several millibars (bar) lower than the pressure inside the main chamber, thereby forming a structure that is convenient for removing silicon oxides, particles, and impurities. However, there is a problem of requiring a separate chamber for forming a vacuum state for the pre-melter. Summary of the invention

[0004] The object of the present invention is to provide an exhaust device for a silicon ingot continuous grower, that is, without using a separate preliminary melter chamber and connecting the preliminary melter and the main chamber in a vacuum atmosphere, silicon oxides, particles and impurities can be removed by the size and position of the gas inlet and gas exhaust port of the preliminary melter and the opening and closing valve structure of the main exhaust port.

[0005] An exhaust device of a silicon ingot continuous grower according to one embodiment of the present invention may include: a chamber, which is divided into a first area and a second area, wherein a vacuum atmosphere is maintained inside the first area, a main crucible is arranged at the center for growing the ingot, and a preliminary melter for supplying molten silicon to the main crucible is arranged on the outer side of the upper end of the second area; and a vacuum pump, which is connected to the chamber and provides vacuum pressure in such a way that a vacuum atmosphere is maintained inside the chamber, wherein a first injection port for allowing an inactive gas to flow in for removing oxides and impurities inside the chamber and a first exhaust port for exhausting gas may be arranged in the first area of ​​the chamber, and a second injection port for allowing an inactive gas to flow in and a second exhaust port for exhausting gas may be arranged in the second area of ​​the chamber.

[0006] In this case, the second injection port may penetrate the upper end of the boundary between the first region and the second region.

[0007] In this case, the second exhaust port may penetrate the outer upper end of the second region.

[0008] In this case, in the chamber, the second region may be formed by protruding from the first region.

[0009] In this case, the first injection port may allow the inert gas to flow downward through the center of the first region where the ingot is raised.

[0010] In this case, the first exhaust port may be disposed at a lower portion of the chamber.

[0011] In this case, the diameter ratio between the first exhaust port and the second exhaust port may be less than 50:1 and greater than 13:1.

[0012] In this case, an on-off valve may be provided at the first exhaust port.

[0013] In this case, the above-mentioned on-off valve may include: a first body, which is formed in a cylindrical shape; a second body, which is assembled on the above-mentioned first body in a rotatable manner, and a radial cover portion is provided at the upper end in a manner that can partially block the channel of the above-mentioned inactive gas; and a third body, which is formed in a flat plate shape, which is assembled on the upper end of the above-mentioned second body in a rotatable manner, and the radial cover portion is provided in a manner that can partially block the channel of the above-mentioned inactive gas together with the cover portion of the above-mentioned first body.

[0014] In this case, the on-off valve may further include a plug that closes an upper end of the on-off valve so that the inert gas cannot pass therethrough.

[0015] According to the above structure, it is not necessary to provide a separate vacuum chamber for preparing the melter in the suction and exhaust device of the silicon ingot continuous growing device of the present invention, thereby reducing the installation cost.

[0016] Furthermore, the present invention forms a structure in which the main melter and the preliminary melter are connected in a vacuum atmosphere of a chamber and the suction and exhaust systems of the main melter and the preliminary melter are respectively provided, so that oxides and impurities can be discharged smoothly and effectively from each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A cross-sectional view of an intake and exhaust device of a silicon ingot continuous grower according to an embodiment of the present invention.

[0018] Figures 2 to 4The figure is a simplified diagram showing an experimental observation of the flow of an inert gas in a manner in which an injection port and an exhaust port are respectively arranged at different positions in an intake and exhaust device of a silicon ingot continuous growth device according to an embodiment of the present invention.

[0019] Figure 5 and Figure 6 The figure is a schematic diagram showing an experimental observation of the flow of an inert gas in a manner in which the diameter of a second exhaust port is changed relative to the first exhaust port in an exhaust and intake device of a silicon ingot continuous growing device according to an embodiment of the present invention.

[0020] Figure 7 It is a perspective view of an on-off valve which is a partial structural element of the intake and exhaust device of the silicon ingot continuous growing device according to one embodiment of the present invention.

[0021] Figure 8 This is an exploded perspective view of an on-off valve which is a partial structural element of an intake and exhaust device of a silicon ingot continuous growing device according to one embodiment of the present invention.

[0022] Fig. 9 The present invention is a plurality of top views showing various usage examples of an on-off valve as a partial structural element of an intake and exhaust device of a continuous silicon ingot growing device according to an embodiment of the present invention.

[0023] Fig.10 The present invention is a plurality of cross-sectional views showing various assembly states of an on-off valve as a partial structural element of an intake and exhaust device of a continuous silicon ingot growing device according to an embodiment of the present invention.

[0024] Description of Reference Numerals

[0025] 1: Ingot growth device

[0026] 2: Ingot 3: Main Crucible

[0027] 4: Reflector 5: Heater

[0028] 10: Chamber 10a: First area

[0029] 10b: Second area 11: First injection port

[0030] 12: First exhaust port 20: Preparatory melter

[0031] 21: Second injection port 22: Second exhaust port

[0032] 30: On-off valve 31: First body

[0033] 31a, 32a, 33a: gas channel 32: second body

[0034] 32b, 33b: Cover 34: Plug DETAILED DESCRIPTION

[0035] The words and terms used in this specification and the scope of protection of the invention should not be limited to the commonly understood meaning or the meaning in the dictionary. Based on the principle that the inventor can define the terms and concepts in order to best explain his invention, they should be interpreted as meanings and concepts that are consistent with the technical ideas of the present invention.

[0036] Therefore, the embodiments described in this specification and the structures shown in the accompanying drawings belong to a preferred embodiment of the present invention and do not fully represent the technical ideas of the present invention. At the time of application of the present invention, the corresponding structures may have multiple equivalents and modifications that can be replaced.

[0037] In this specification, terms such as "including" or "having" should be understood as being used only to describe the existence of features, numbers, steps, actions, structural elements, components or combinations thereof recorded in the specification, rather than excluding the existence or additional possibility of one or more other features, numbers, steps, actions, structural elements, components or combinations thereof.

[0038] Unless otherwise specified, a statement that a certain structural element is located “in front of,” “behind,” “above,” or “below” another structural element includes not only a situation where it is located “in front of,” “behind,” “above,” or “below” another structural element in direct contact with the other structural element, but also a situation where the other structural element is disposed in between. Furthermore, unless otherwise specified, a statement that a certain structural element is “connected to” another structural element includes not only a situation where it is directly connected, but also a situation where it is indirectly connected.

[0039] Hereinafter, the suction and exhaust device of the silicon ingot continuous growth device of the present invention will be described with reference to the accompanying drawings. In this specification, in order to simplify the accompanying drawings, in the process of describing the suction and exhaust device of the silicon ingot continuous growth device of the embodiment of the present invention, the structure irrelevant to the content of the present invention will not be shown in detail or will not be shown, and the suction and exhaust device of the silicon ingot continuous growth device of the present invention will be described with the content related to the idea of ​​the present invention as the center.

[0040] Reference Figures 1 to 8 The exhaust and intake device of the silicon ingot continuous grower 1 according to an embodiment of the present invention may include a chamber 10 , a vacuum pump (not shown) and an on-off valve 30 .

[0041] Reference Figures 1 to 5 The chamber 10 may include: a first region 10a, in which a vacuum atmosphere is maintained, and a main crucible 3 heated by a heater 5 is arranged at the center for growing the ingot 2; and a second region 10b, in which a preliminary melter 20 for supplying molten silicon to the main crucible 3 is arranged at the outer side of the upper end.

[0042] In this case, the chamber 10 may be formed into a cylindrical shape, and the main crucible 3 may be disposed at the center. Figure 1 Since the chamber 10 is formed in a shape in which the pre-melter 20 is added to the outer side of the upper end, a space for setting is required. Therefore, the chamber 10 may be formed in a shape in which the outer side of the upper end protrudes outward compared to other parts. That is, a space required for adding the second region 10b is added along the outer direction. Of course, in this state, although the suction and exhaust device can be formed by forming only the original first injection port 11 and the first exhaust port 12, this may cause the flow of the original inert gas to change due to the addition of the pre-melter 20 and cause problems. In order to improve this, a second injection port 21 and a second exhaust port 22 may be provided in the second region 10b.

[0043] The chamber 10 is maintained in a vacuum atmosphere by a vacuum pump connected to the first exhaust port 12 and the second exhaust port 22. That is, the vacuum pump is connected to the chamber 10 to provide vacuum pressure so that the chamber 10 is maintained in a vacuum atmosphere.

[0044] In this case, a first injection port 11 for allowing an inactive gas to flow in and a first exhaust port 12 for exhausting the gas may be provided in the first area 10a of the chamber 10, and a second injection port 21 for allowing an inactive gas to flow in and a second exhaust port 22 for exhausting the gas may be provided in the second area 10b of the chamber 10.

[0045] In this case, the first injection port 11 may allow the inert gas to flow downward through the central portion of the first region 10 a where the ingot 2 is raised.

[0046] On the other hand, the first exhaust port 12 may be located at a lower portion of the chamber 10 .

[0047] Therefore, the inert gas flowing into the first injection port 11 moves to the side through the main crucible 3 and the reflector 4, then descends along the side of the main crucible 3, and then is exhausted to the outside of the chamber 10 through the first exhaust port 12. In this case, argon gas can be used as the inert gas, and the flow of the inert gas can be exhausted by pushing away oxides and impurities.

[0048] In this case, the second injection port 21 may penetrate the upper end of the boundary between the first region 10a and the second region 10b. In this way, by flowing the inert gas into the boundary, a gas curtain effect is formed, and the first region 10a and the second region 10b can be divided at the spatial level or the gas flow level.

[0049] In this case, the second exhaust port 22 may penetrate the outer upper end of the second region 10b. That is, the second exhaust port 22 may be disposed at the outer side of the highest position in the second region 10b.

[0050] The positions of the second injection port 21 and the second exhaust port 22 can be selected with reference to the simulation experiment example.

[0051] Figures 2 to 4 The graph is a gas flow captured by performing an experiment by changing the position in a state where the argon injection amount of the second injection port 21 is 15 lpm (liter per minute) and the diameter of the second exhaust port 22 is 2 mm.

[0052] In this case, if Figure 2 As shown, when the second injection port 21 is arranged at the boundary between the first area 10a and the second area 10b and the second exhaust port 22 is located at the upper end, the oxides produced in the crucible 3 for growing the ingot and the oxides produced in the preliminary melter 20 can be discharged through the upper exhaust port 22.

[0053] On the other hand, Figure 3 As shown, the second injection port 21 is located at Figure 2 When the second exhaust port 22 is arranged at the lower end at the same position as the position in the above embodiment, there is a disadvantage that oxides generated in the crucible 3 where the ingot is grown may flow into the molten silicon in the preliminary melter 20 .

[0054] In this case, if Figure 4 As shown, when there is only the second injection port 21 for molten silicon and only the first exhaust port is used as an exhaust port, there is a possibility that oxides generated in the preliminary melter 20 may flow into the molten silicon for growing an ingot.

[0055] According to the experimental results described above, in the exhaust device of the silicon ingot continuous growing device 1 according to one embodiment of the present invention, it is possible to Figure 2 The second injection port 21 and the second exhaust port 22 are arranged in the ingot continuous growth device 1 in the shape shown in FIG.

[0056] On the other hand, in addition to the injection port and the exhaust port, the gas flow inside the chamber 10 may also be affected by the diameter of the exhaust port.

[0057] As an example, simulation results have confirmed that when the pipe diameter of the first exhaust port 12 is 94 mm, if the diameter of the second exhaust port 22 of the preliminary melter 20 is set to 30 mm, which is about 1 / 3 of the diameter, argon gas will flow back.

[0058] If the argon gas flows back, carbon in the graphite structure located at the bottom may flow into the molten silicon on which the ingot is grown, which may have an adverse effect on the quality. In addition, if the oxide vapor deposit or dust contacts the surface of the ingot due to the backflow of the argon gas, crystal defects may be caused, which may cause a decrease in productivity.

[0059] on the other hand, Figure 5 and Figure 6 The second injection port 21, the first exhaust port 12 and the second exhaust port 22 are located at Figure 2 The gas flow is observed by changing the diameter of the second exhaust port 22 in the state shown in the figure. Figure 5 and Figure 6 As shown, the amount of argon injected into the second injection port 21 is 15 lpm (liter per minute), and the pipe diameter of the first exhaust port 12 is 94 mm.

[0060] exist Figure 5 In the embodiment, the diameter of the second exhaust port 22 in part (a) is set to 2 mm, the diameter of the second exhaust port 22 in part (b) is set to 5 mm, and the diameter of the second exhaust port 22 in part (c) is set to 6 mm. Figure 5 In the case of the size shown, it can be confirmed that the flow of argon gas (downward arrow direction) has become smooth.

[0061] On the other hand, Figure 6 In the embodiment, the diameter of the second exhaust port 22 in part (a) is set to 7 mm, the diameter of the second exhaust port 22 in part (b) is set to 15 mm, and the diameter of the second exhaust port 22 in part (c) is set to 30 mm. Figure 6 In the case of the size shown, it can be confirmed that a backflow occurs in the flow of argon gas (in the direction of the upward arrow).

[0062] According to the experimental results described above, when the argon injection rate injected through the second injection port 21 is 15 lpm (liter per minute) and the pipe diameter of the first exhaust port 12 is 94 mm, backflow does not occur if the diameter of the second exhaust port 22 is set to be less than 7 mm.

[0063] Therefore, according to one embodiment of the present invention, if the diameter of the second exhaust port 22 is set to 6 mm, under the conditions that the argon injection amount at the second injection port 21 is 15 lpm (liter per minute) and the pipe diameter of the first exhaust port 12 is 94 mm, the diameter is the largest among the diameters that do not generate backflow without generating backflow, and thus manufacturing can be performed easily.

[0064] According to the experimental results as described above, when the diameter ratio between the first exhaust port and the second exhaust port is set in a manner that is less than 50:1 and greater than 13:1, and more preferably, when the diameter ratio is set in a manner that is less than 16:1 and greater than 13:1, the growth furnace can be manufactured in a manner that does not generate backflow in the flow of the fluid passing through the injection port and the exhaust port.

[0065] In this case, an on-off valve 30 may be provided at the first exhaust port 12 .

[0066] In this case, refer to Figures 7 to 10 The on-off valve 30 may include a first body 31 to a third body 33 .

[0067] The first body 31 may be formed into a cylindrical shape so that a gas passage 31 a may be provided at the center, and a locking portion 31 b may be provided for assembly.

[0068] The second body 32 can be rotatably assembled to the first body 31, and a radial cover 32b is provided at the upper end to partially block a portion of the inert gas passage 32a. The cover 32b is provided to block about 90 degrees, but the present invention is not limited thereto.

[0069] In this case, a flange 32c may be provided at the upper end of the second body 32 so as to be clamped on the upper end of the first body 31 for assembly. Thus, the outer diameter of the second body 32 will be smaller than the inner diameter of the first body 31, and if the second body 32 is inserted into the first body 31, the flange 32c will be clamped on the first body 31 and the insertion will stop, thereby completing the assembly.

[0070] The third body 33 is rotatably assembled on the upper end of the second body 32 , and the radial cover 33 b may be provided to partially block the passage 323 a of the inert gas together with the cover 32 b of the second body 32 .

[0071] In this case, the third body 33 is formed in a disk shape and is provided with a gas passage 33a and a cover 33b. The cover 33b can be formed in a manner of covering about 180 degrees, but is not limited thereto.

[0072] In this case, the on-off valve 30 may further include a plug 34 for sealing the upper end of the on-off valve 30 in a manner that the inert gas cannot pass through. The plug 34 may be assembled in the on-off valve 30 in a manner that replaces the third body 33 or blocks the gas passages 31a, 32a, and 33a above the third body 33.

[0073] Figure 7and Figure 8 The first body 31 , the second body 32 , and the third body 33 are assembled, and the gas channels 31 a , 32 a , and 33 a are opened at 45 degrees on the radius so that the gas channels 31 a , 32 a , and 33 a are opened by only 25%.

[0074] Fig. 9 Parts (a) to (f) of FIG. 3 show states in which the gas passage of the on-off valve 30 is opened at different opening degrees. Fig. 9 Part (a) shows a case where only the first body 31 is provided at the first exhaust port 12 , which is in a 100% open state. Fig. 9 Part (b) shows a state where only the first body 31 and the second body 32 are provided at the first exhaust port 12 , and the gas passage is opened by 75%. Fig. 9 Part (c) shows a state where the first body 31 , the second body 32 , and the third body 33 are assembled and only 50% of the cover 33 b of the third body 33 and the cover 32 b of the second body 32 overlap each other. Fig. 9 Part (d) and Fig. 9 Part (e) shows Fig. 9 In the state shown in part (c), when the third body 33 is rotated at a desired angle, the opening degree of the gas passage can be adjusted within a range of 50% to 75%. Fig. 9 Part (f) of FIG. 1 shows a state where the first exhaust port is closed by assembling the plug 34 at the upper end. Fig. 9 As shown in parts (a) to (f) of the present invention, the flow rate of the gas flowing in the gas passage can be adjusted by adjusting the opening degree of the on-off valve 30 .

[0075] on the other hand, Fig.10 Part (a) shows a state where the gas passage is closed by providing a plug 34 at the upper end of the on-off valve. Fig.10 Part (b) shows a state in which the opening degree of the gas passage can be adjusted by providing all of the first body 31 , the second body 32 , the third body 33 , etc. at the upper end of the on-off valve. Fig.10 Part (c) of FIG. 1 shows a state where the first body 31 is provided only at the first exhaust port 12 so that the gas passage is completely open. Fig.10 According to the structures shown in parts (a) to (c), the flow rate of the gas flowing in the gas passage can be adjusted by adjusting the opening degree of the on-off valve 30 .

[0076] As described above, according to an embodiment of the present invention, the flow rate of the gas passing through the first exhaust port having a large diameter can be adjusted according to the surrounding environment and situation by adjusting the opening degree of the on-off valve 30 .

[0077] The embodiments of the present invention are described above, but the concept of the present invention is not limited to the embodiments presented in this specification. Ordinary technicians in the technical field to which the present invention belongs who understand the concept of the present invention can easily propose other embodiments within the scope of the same concept by adding, changing, deleting, adding, etc. structural elements, but this also falls within the scope of the concept of the present invention.

Claims

1. A suction and exhaust device for a silicon ingot continuous grower, characterized in that: include: The chamber is divided into a first area and a second area. The first area maintains a vacuum atmosphere inside, a main crucible is arranged at the center for growing an ingot, and a preliminary melter for supplying molten silicon to the main crucible is arranged outside the upper end of the second area; a vacuum pump connected to the chamber to provide vacuum pressure in such a way that a vacuum atmosphere is maintained inside the chamber; and a reflector plate extending from an upper end of the second region along a boundary between the first region and the second region to an upper side of the main crucible; A first injection port for allowing an inert gas to flow in and a first exhaust port for exhausting the gas are provided in the first region of the chamber. A second injection port for inert gas to flow in and a second exhaust port for exhausting gas are provided in the second region of the chamber. The second injection port penetrates the reflector located at the upper end of the boundary between the first region and the second region, and the first region and the second region are divided by the inert gas flow by flowing the inert gas toward the boundary. The second exhaust port passes through the upper end of the outer side of the second region, and the second exhaust port is at the highest position in the second region. The distance between the second injection port and the main crucible is relatively smaller than the distance between the second exhaust port and the main crucible. A diameter ratio between the first exhaust port and the second exhaust port is less than 16:1 and greater than 13:

1.

2. The exhaust and intake device of the silicon ingot continuous growing device according to claim 1, characterized in that: In the chamber, the second region protrudes from the first region.

3. The exhaust and intake device of the silicon ingot continuous growing device according to claim 1, characterized in that: The first injection port allows the inert gas to flow downward through the center of the first region where the ingot is raised.

4. The exhaust and intake device of the silicon ingot continuous growing device according to claim 1, characterized in that: The first exhaust port is disposed at the lower portion of the chamber.

5. The exhaust and intake device of the silicon ingot continuous growing device according to claim 1, characterized in that: An on-off valve is provided at the first exhaust port.

6. The exhaust and intake device of the silicon ingot continuous growing device according to claim 5, characterized in that: The above-mentioned on-off valve comprises: A first body formed into a cylindrical shape; A second body is rotatably assembled to the first body, and a radial cover is provided at the upper end thereof so as to partially block the passage of the inert gas; and The third body is formed in a flat plate shape and is rotatably assembled on the upper end of the second body. A radial cover is provided so as to partially block the passage of the inert gas together with the cover of the first body.

7. The exhaust and intake device of the silicon ingot continuous growing device according to claim 6, characterized in that: The on-off valve further includes a plug that closes an upper end of the on-off valve so that the inert gas cannot pass therethrough.

Images