Raw material charging aid

Abstract

To provide a raw material charge auxiliary tool that can make it easy to charge a silicon raw material having a proper grain size into a charge pipe, and suppress fine powder from being charged as much as possible.SOLUTION: A raw material charge auxiliary tool 1 is a tool that is attachable to and detachable from a charge pipe for re-charging or additionally charging a granular silicon raw material into a single crystal lifting device, and charges the silicon raw material into the charge pipe, and also comprises a slider 10 which is made of a quartz-mage substantially plate-like member and constitutes a flow passage for the silicon raw material. A tip part of the slider 10 is provided with a tubular insert part 13 inserted into an opening of the charge pipe, and the slider 10 is provided with a plurality of through parts penetrating from the top surface to the back surface.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a raw material charging auxiliary tool used when charging a polycrystalline silicon raw material into a charge tube, which is used in the production of a silicon single crystal by the Chochralski method (hereinafter referred to as the "CZ method").

Background Art

[0002] A multiplexing method is known as a method for producing a silicon single crystal by the CZ method. In the multiplexing method, after pulling up a silicon single crystal, a silicon raw material is additionally supplied (recharged) into the same quartz crucible and melted, and a silicon single crystal is pulled up from the obtained silicon melt. By repeating such a raw material supply step and a single crystal pulling step, a plurality of silicon single crystals are produced from one quartz crucible. According to the multiplexing method, it is possible to reduce the cost of the quartz crucible per silicon single crystal. In addition, since the frequency of disassembling the chamber and replacing the quartz crucible can be reduced, the operation efficiency can be improved.

[0003] The additional supply of the silicon raw material may also be performed in a so-called single-pulling method in which only one silicon single crystal is produced from one quartz crucible. When the initially charged solid silicon raw material in the quartz crucible is melted, the volume decreases and an empty volume is generated. By additionally charging the silicon raw material into this quartz crucible and pulling up a single crystal from a large amount of silicon melt, a long silicon single crystal can be grown, thereby improving the operation efficiency.

[0004] In the multiplied method described above, a special raw material supply device called a charge tube is used in the recharge step, where silicon raw material is fed in multiple times, and in the additional charge step, which is used to increase the raw material filling rate in the quartz crucible (see Patent Documents 1 and 2). The charge tube is a cylindrical container made of quartz, and the silicon raw material is charged into the quartz crucible in the single crystal pulling apparatus by opening the bottom lid provided at the lower end of the charge tube and letting the silicon raw material inside the charge tube fall in.

[0005] In order to recharge or add silicon raw material to a single crystal pulling apparatus using a charging tube, silicon raw material must first be charged into the charging tube. As a jig for charging silicon raw material into the charging tube, for example, Patent Document 3 describes a raw material charging aid that is attached to the opening of the charging tube and guides the silicon raw material to flow into the charging tube. This raw material charging aid has a main guide part that constitutes a flow path for the silicon raw material, and at least the part that comes into contact with the silicon raw material is made of quartz. By using the raw material charging aid, it is less likely that silicon raw material will spill into the charging tube when charging, and the parts attached to the charging tube do not hinder the charging of silicon raw material, making it easier to charge the silicon raw material and preventing contamination of the silicon raw material. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2006-089294 [Patent Document 2] Japanese Patent Publication No. 2008-088002 [Patent Document 3] Japanese Patent Publication No. 2017-202947 [Overview of the project] [Problems that the invention aims to solve]

[0007] The silicon raw material used for recharging or additional charging is irregularly shaped, granular silicon called chunks, with an average particle size of about 40-50 mm. The silicon raw material is charged into the charging tube by pouring a large amount of silicon granules into the tube.

[0008] Although granular silicon is delivered in bags of predetermined sizes, it is manufactured by crushing polycrystalline silicon rods, resulting in a shape with sharp corners. During transport, the granular silicon lumps collide and rub against each other, inevitably generating fine powder inside the bags. Furthermore, when granular silicon lumps are dropped onto a charging aid as shown in Patent Document 3, the impact of the drop causes the granular silicon lumps to break, generating fine raw material powder. Therefore, if the silicon raw material is charged directly into the charging tube, the silicon fine powder will also be charged into the charging tube. According to the inventor's experiments, when the silicon raw material in the charge tube contains a large amount of fine powder, when the silicon raw material in the charge tube is dropped from above into the quartz crucible to recharge or add to the quartz crucible, the fine powder is blown into the air and adheres to the furnace structure located above the quartz crucible (especially the inner surface of the heat shield). The silicon fine powder that adheres to the furnace structure then falls onto the surface of the silicon melt during single crystal growth, and if the silicon fine powder is incorporated into the solid-liquid interface before dissolving into the silicon melt, it can cause dislocation formation or twinning of the silicon single crystal.

[0009] Therefore, it is necessary to remove fine particles from the silicon raw material to prevent them from being incorporated into the charging tube, but it is difficult to remove only silicon fine particles (~a few mm) by hand.

[0010] This invention was completed based on the finding that the supply of silicon fine powder during additional charging or recharging causes dislocation formation in single crystals. The objective of this invention is to provide a raw material charging aid that facilitates the charging of silicon raw materials with appropriate particle size into the charging tube and minimizes the charging of fine powder. [Means for solving the problem]

[0011] To solve the above problems, the raw material charging aid according to the present invention is detachably attached to a charging tube for recharging or additionally charging granular silicon raw material into a single crystal pulling apparatus, and is a raw material charging aid for charging the silicon raw material into the charging tube, comprising a substantially plate-shaped member made of quartz, and equipped with a slider that constitutes a flow path for the silicon raw material, the tip of the slider is provided with a tubular insertion part that is inserted into the opening of the charging tube, and the slider is provided with a plurality of through-parts that penetrate from the surface to the back.

[0012] The raw material charging aid according to the present invention is attached to the opening of the charging tube and guides the flow of silicon raw material into the charging tube, thereby widening the opening of the charging tube and making it easier to charge the silicon raw material. Furthermore, according to the present invention, only silicon particles with an appropriate particle size can be sent into the charging tube, and fine powder contained in the silicon raw material can be shaken off as it is sent into the charging tube. Therefore, dislocation formation and twinning of silicon single crystals caused by fine powder can be prevented.

[0013] In the present invention, the through-hole may be a slit parallel to the direction in which the silicon raw material is poured, or it may be a round hole. In this case, the width of the slit or the diameter of the round hole is preferably 3 to 10 mm. By making the through-hole have an appropriate shape and size in this way, fine powder contained in the silicon raw material can be removed, and only silicon particles with the desired particle size can be sent into the charging tube.

[0014] In the present invention, the slider preferably comprises a main guide portion made of an elongated, substantially plate-shaped member having a curved surface, a first wing portion provided at one end of the main guide portion in the width direction and having a downward sloping surface toward the main guide portion, and a second wing portion provided at the other end of the main guide portion in the width direction and having a downward sloping surface toward the main guide portion, with the through portion provided at the main guide portion, the first wing portion, and the second wing portion, respectively. By widening the width of the slider in this way, the acceptance of silicon raw material can be facilitated.

[0015] The raw material charging aid according to the present invention preferably further comprises a back plate that is detachably provided on the back side of the slider and serves as a tray for raw material powder that falls from the through-hole. In this case, the back plate preferably comprises a center cover portion that covers the back of the main guide portion, a first wing cover portion that covers the back of the first wing portion, and a second wing cover portion that covers the back of the second wing portion. Furthermore, from the viewpoint of durability, the back plate is preferably made of Teflon®, polyvinyl chloride resin, quartz, or the like. This ensures that fine silicon raw material powder is reliably collected and prevents deterioration of the indoor environment due to the scattering of fine powder in the work room.

[0016] Preferably, the back plate is provided with an exhaust port, and preferably, the exhaust port is located closer to the front end than to the center of the longitudinal direction of the center cover. By connecting a vacuum device to the exhaust port and using suction, fine powder on the back plate can be collected. This also promotes the fall of fine powder on the slider into the penetration portion.

[0017] Preferably, a handle is provided on the back of the slider, and an opening is provided in the back plate through which the handle passes. This makes it easier to align the back plate with the slider. [Effects of the Invention]

[0018] According to the present invention, it is possible to provide a raw material charging assist tool that facilitates charging of silicon raw materials having an appropriate particle size into a charging tube and that can prevent charging of fine powder as much as possible.

Brief Description of the Drawings

[0019] [Figure 1] FIGS. 1(a) to (d) are diagrams showing the configuration of a charging tube used when recharging or additionally charging silicon raw materials into a single crystal pulling apparatus, where (a) shows a state in which the bottom cover is closed and no silicon raw material is accommodated, (b) shows a state in which the bottom cover is closed and a silicon raw material is accommodated, (c) shows a state in which the bottom cover is open and no silicon raw material is accommodated, and (d) shows a state in which the bottom cover is open and the internal silicon raw material is being discharged. [Figure 2] FIG. 2 is a schematic plan view showing the configuration of an opening on the upper end side of the charging tube. [Figure 3] FIG. 3 is a schematic perspective view showing the configuration of a raw material charging assist tool according to a first embodiment of the present invention, particularly a perspective view seen from above. [Figure 4] FIG. 4 is a schematic perspective view showing the configuration of a raw material charging assist tool according to a first embodiment of the present invention, particularly a perspective view seen from below. [Figure 5] FIG. 5 is a schematic perspective view showing a slider alone. [Figure 6] FIG. 6 is a schematic perspective view showing a back plate alone. [Figure 7] FIG. 7 is a schematic side view for explaining a method of charging silicon raw materials into a charging tube using a raw material charging assist tool. [Figure 8] FIG. 8 is a schematic diagram for explaining a recharging or additional charging process of silicon raw materials. [Figure 9] FIG. 9 is a schematic perspective view showing the configuration of a raw material charging assist tool according to a second embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0020] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. Note that, for convenience in order to make the features of the present invention easier to understand, the drawings may highlight key parts, and the dimensional ratios of each component may not be the same as those in reality.

[0021] First, we will describe the charging tube used when recharging or adding silicon raw material to the single crystal pulling apparatus.

[0022] Figures 1(a) to 1(d) are schematic cross-sectional views showing the configuration of a charge tube according to an embodiment of the present invention, where (a) shows the bottom lid closed and no silicon raw material is contained, (b) shows the bottom lid closed and silicon raw material is contained, (c) shows the bottom lid open and no silicon raw material is contained, and (d) shows the bottom lid open and the silicon raw material inside is released.

[0023] As shown in Figures 1(a) to (d), the charge tube 100 comprises a charge tube body 101 for containing granular silicon raw material S, a metal flange member 102 provided at the opening 101a at the upper end of the charge tube body 101, a bottom cover 103 for opening and closing the opening 101b at the lower end of the charge tube body 101, a shaft 104 for supporting the bottom cover 103, and a guide tube 105 into which the shaft 104 is inserted.

[0024] The charge tube body 101 is a cylindrical member made of quartz glass, and its diameter is set to be equal to or slightly smaller than the diameter of the silicon single crystal to be pulled up. A through hole is provided in the center of the flange member 102 that partially closes the opening 101a at the upper end of the charge tube body 101, and the shaft 104 and guide tube 105 are inserted into the charge tube body 101 through the through hole and pass through the charge tube body 101 to the upper end of the bottom cover 103.

[0025] The bottom cover 103 is a cone-shaped member with heat-insulating properties and has an inclined surface to allow the raw materials inside the charge tube body 101 to fall smoothly when the bottom cover 103 is opened.

[0026] The shaft 104 is a component for raising and lowering the bottom cover 103, and extends vertically through the guide tube 105 and is connected to the upper end of the bottom cover 103. The upper end of the shaft 104 protrudes above the opening 101a at the upper end of the charge tube body 101.

[0027] The guide tube 105 is provided to prevent the shaft 104 from coming into contact with the silicon raw material S inside the charge tube body 101. The guide tube 105 is made of quartz glass, just like the charge tube body 101, and its lower end is connected to the upper end of the bottom cover 103, so the guide tube 105 is integrated with the bottom cover 103. The upper end of the guide tube 105 also passes through the through hole in the center of the flange member 102 and protrudes above the flange member 102, and the amount of protrusion is such that the protruding state is maintained even when the bottom cover 103 is lowered to its lowest position.

[0028] Figure 2 is a schematic plan view showing the configuration of the opening 101a at the upper end of the charge pipe 100.

[0029] As shown in Figure 2, screw holes 102a are provided in appropriate locations on the flange member 102 located on the upper end side of the charge tube body 101. The flange member 102 also has a support piece 102b that extends toward the center of the charge tube 100, and a through hole 102c is provided at the tip of the support piece 102b through which the shaft 104 and the guide tube 105 pass. As a result, the shaft 104 and the guide tube 105 are positioned on the central axis of the charge tube 100. Thus, the opening 101a of the charge tube 100, which is the raw material charging port, is not completely open, but is partially closed by the parts attached to the charge tube 100, making it difficult to charge the silicon raw material S.

[0030] Such a charge tube 100 is connected to the tip of the pulling shaft (wire) of the single crystal pulling apparatus and installed inside the apparatus. Specifically, the upper end of the shaft 104 of the charge tube 100 is connected to the tip of the wire, thereby positioning the charge tube 100 above the quartz crucible inside the single crystal pulling apparatus. After that, the wire is retracted to lower the charge tube 100, and then the charge tube body 101 is lifted relatively to open the bottom cover 103, thereby dropping the silicon raw material S into the quartz crucible.

[0031] Next, a raw material charging aid used when charging silicon raw material S into such a charging tube 100 will be described.

[0032] Figures 3 and 4 are schematic perspective views showing the configuration of the raw material charging aid 1 according to the first embodiment of the present invention, where Figure 3 is a perspective view from above and Figure 4 is a perspective view from below.

[0033] As shown in Figures 3 and 4, the raw material charging aid 1 is a component that can be attached to and detached from the charging pipe 100 and comprises a slider 10 which serves as a receptacle for the silicon raw material S and forms a flow path for the silicon raw material S to flow into the charging pipe 100, and a back plate 20 provided on the back side of the slider 10.

[0034] Figure 5 is a simplified perspective view showing the slider 10 alone.

[0035] As shown in Figures 3, 4, and 5, the slider 10 is a roughly plate-shaped member made of quartz glass that constitutes a flow path for the silicon raw material S. It has a main guide portion 11 that constitutes a flow path for the silicon raw material S and is located in the center in the width direction, wing portions 12 provided on the left and right sides when viewed from the rear of the main guide portion 11, an insertion portion 13 which is the tip of the main guide portion 11 and is inserted into the opening 101a of the charge tube 100, and a handle 14 provided on the back of the main guide portion 11. In this embodiment, the raw material charging aid 1 is made entirely of high-purity quartz, so contamination of the silicon raw material S can be prevented.

[0036] The main guide portion 11 is a long, narrow plate-shaped member in the Y direction in the figure, and has a curved surface that decreases in height from both ends in the width direction (X direction) perpendicular to the longitudinal direction towards the center. Preferably, the curvature of the curved surface is about the same as the curvature of the charge pipe 100. Preferably, the length of the main guide portion 11 is sufficiently longer than the upper end protruding portion of the shaft 104 of the charge pipe 100.

[0037] The wing section 12 is provided to expand the range of the silicon raw material S receiving tray (charging range), which is not sufficiently wide with the main guide section 11 alone, and to charge the silicon raw material S while avoiding the shaft 104 protruding from the opening 101a of the charging pipe 100. The wing section 12 consists of a left wing section 12L (first wing section) provided at the left end of the main guide section 11 in the direction of silicon raw material flow (Y direction), and a right wing section 12R (second wing section) provided at the right end of the main guide section 11, and has a downward sloping surface from the outside in the width direction toward the center (main guide section 11). Therefore, silicon raw material S that falls onto the left wing section 12L and the right wing section 12R is collected by the main guide section 11 as it flows down the sloping surface.

[0038] In this embodiment, the shape of the left wing portion 12L differs from that of the right wing portion 12R, and the size of the left wing portion 12L is larger than that of the right wing portion 12R. This is to increase the size of only the left wing portion 12L, which is often used as the charging direction for the silicon raw material S, and to prevent the raw material charging aid 1 from becoming unnecessarily large and heavy.

[0039] The wing portion 12 is particularly advantageous when charging silicon raw material S into a large charge tube 100. A large charge tube 100 requires a large amount of silicon raw material S to be charged, which necessitates a larger raw material charging aid 1, making it difficult to handle. Therefore, when charging silicon raw material S into a charge tube 100 used to supply additional silicon raw material S to a single crystal pulling apparatus for pulling silicon single crystals with a diameter of 300 mm or more, it is preferable to use a raw material charging aid 1 equipped with a wing portion 12.

[0040] The insertion section 13 forms a passage that is surrounded all around by the ceiling surface 13a, and the opening 13b at the tip of the insertion section 13 serves as the discharge port for the silicon raw material S. As shown in Figures 4(a) and (b), a stopper 16 is provided on the back of the tip of the main guide section 11, and the stopper 16 abuts against the flange member 102 at the upper end of the rim of the charge pipe 100, thereby restricting the insertion of the insertion section 13 further in.

[0041] A handle 14 is provided on the back of the main guide section 11. Large quartz glass products are heavy and fragile, and those with a special shape including the wing section 12 are particularly difficult to handle. However, by providing a handle 14 on the raw material charging aid 1, handling can be made easier and safety can be enhanced. The handle 14 can be installed anywhere, allowing the raw material charging aid 1 to be placed in a position that is easy to handle.

[0042] In this embodiment, the main guide portion 11, the left wing portion 12L, and the right wing portion 12R are provided with a plurality of slits 15. The slits 15 are linear through-holes in plan view that penetrate from the upper surface (front) to the lower surface (back) of the main guide portion 11, the left wing portion 12L, and the right wing portion 12R, and are configured so that fine raw material powder contained in the silicon raw material S rolling on the upper surface of the slider 10 falls through the slits 15.

[0043] The width of the slit 15 is preferably about 3 to 10 mm. If the width of the slit 15 is too small, fine silicon powder cannot be removed, and if it is too large, usable silicon particles will also be removed. Typically, the size of silicon particles is 30 to 60 mm, and even the smallest ones are around 20 mm. Therefore, by setting the width of the slit 15 to 3 to 10 mm, only silicon particles of a suitable size as raw material can be sent into the charging tube 100, and fine silicon powder smaller than the width of the slit 15 can be removed.

[0044] The length and pitch of the slits 15 are not particularly limited as long as they can remove silicon fine powder, and are appropriately determined considering the balance between the strength of the main guide portion 11 and the wing portion 12 and the fine powder removal capacity. The slits 15 are preferably formed parallel to the feeding direction of the silicon raw material S, but may also be formed perpendicular to the feeding direction or oblique to the feeding direction.

[0045] A back plate 20 is attached to the back of the slider 10, which serves as a tray for receiving fine powder that falls through the slit 15. From the viewpoint of durability, the back plate 20 is preferably made of Teflon (registered trademark), polyvinyl chloride resin, quartz, etc. The back plate 20 is configured to be detachable from the slider 10 and can be easily attached by fitting it from the back of the slider 10. There is a gap of several centimeters between the back of the slider 10 and the top surface of the back plate 20, forming a closed space that traps the fine powder.

[0046] Figure 6 is a schematic perspective view showing the backplate 20 alone.

[0047] As shown in Figures 3, 4, and 6, the backplate 20 is composed of a center cover portion 21 that covers the back of the main guide portion 11, a wing cover portion 22 that covers the back of the wing portion 12, and a wall portion 23 provided on the outer periphery of the wing cover portion 22. The wing cover portion 22 is composed of a left wing cover portion 22L provided on the left side of the center cover portion 21 and a right wing cover portion 22R provided on the right side of the center cover portion 21.

[0048] The left wing cover portion 22L has substantially the same shape as the left wing portion 12L of the slider 10 in a plan view and covers the entire back surface of the left wing portion 12L. The right wing cover portion 22R has substantially the same shape as the right wing portion 12R of the slider 10 in a plan view and covers the entire back surface of the right wing portion 12R.

[0049] The center cover portion 21 of the back plate 20 has substantially the same shape as the main guide portion 11 in plan view and covers the entire back surface of the main guide portion 11. However, the center cover portion 21 of the back plate 20 is provided with an opening 20a to prevent interference with the handle 14 of the slider 10 when combined with the main guide portion. This allows the handle 14 to protrude below the back plate 20.

[0050] In this embodiment, an exhaust port 20b for collecting fine powder is provided near the front of the back plate 20. Preferably, the exhaust port 20b is located closer to the front than the center of the longitudinal direction of the center cover portion 21. By connecting a vacuum device to the exhaust port 20b and using suction, the falling of fine powder on the slider 10 can be promoted, and fine powder present in the space between the back of the slider 10 and the upper surface of the back plate 20 can be sucked up and collected.

[0051] Figure 7 is a schematic side view illustrating a method for charging silicon raw material into a charging tube 100 using a raw material charging aid 1.

[0052] As shown in Figure 7, when charging the silicon raw material S into the charging tube 100, the charging tube 100 is first tilted and installed together with the carrier case 110 so that it slopes downward from the top end to the bottom end. The tilt angle θ of the charging tube 100 is preferably 30 to 60 degrees. If the silicon raw material S is charged with the charging tube 100 in an upright position, the charging tube 100 may break due to the impact of dropping it, but damage to the charging tube 100 can be prevented by tilting it in this way.

[0053] Next, while holding the handle 14, the raw material charging aid 1 is set into the opening 101a at the upper end of the charging pipe 100. The insertion part 13 of the raw material charging aid 1 is inserted into the opening 101a of the charging pipe 100, and the stopper 16 comes into contact with the end face of the flange member 102 of the charging pipe 100.

[0054] Next, the suction port 201 of the vacuum device 200 is set into the exhaust port 20b of the back plate 20 of the raw material charging aid 1. In this way, the silicon fine powder Sb that falls onto the back plate 20 during the charging of the silicon raw material S can be sucked up.

[0055] Next, a resin cover 107 is placed over the shaft 104 that protrudes above the opening 101a of the charging tube 100. This prevents contamination of the silicon raw material S by contact with the metal shaft 104. Since the shaft 104 inside the charging tube 100 is covered by a quartz guide tube 105, the silicon raw material S inside the charging tube 100 does not come into contact with the metal shaft 104. Alternatively, the raw material charging aid 1 may be set in the charging tube 100 after the cover 107 has been placed over the shaft 104 of the charging tube 100.

[0056] Next, silicon raw material S is charged from the wing portion 12 side. Silicon particles Sa of the appropriate size flow from the wing portion 12 to the main guide portion 11, and then flow down the main guide portion 11 and are charged into the charging tube 100. Since the shaft 104 connected to the bottom cover 103 of the charging tube 100 protrudes from the opening 101a of the charging tube 100, it is difficult to pour the silicon raw material S directly into the opening 101a. However, in this embodiment, the main guide portion 11 and wing portion 12 of the raw material charging aid 1, which extend outside the opening 101a, collect the silicon raw material S and pour it into the opening 101a, so that the silicon raw material S can be easily charged into the charging tube 100.

[0057] During the charging of the silicon raw material S, the vacuum device 200 is operated to promote the fall of silicon fine powder Sb on the slider 10 and to collect the silicon fine powder Sb that has fallen onto the back plate 20. In this way, it is possible to prevent the silicon fine powder Sb from flowing into the charging pipe 100 and to efficiently collect the silicon fine powder Sb. Furthermore, it is possible to prevent deterioration of the cleanliness of the work area due to the scattering of silicon fine powder Sb.

[0058] Subsequently, the raw material charging aid 1 is removed from the charging tube 100 and the silicon raw material S is charged into the charging tube 100, thereby completing the series of work steps.

[0059] As described above, the method of charging the charge tube 100 with silicon raw material S according to this embodiment prevents cracking of the charge tube 100 because the silicon raw material S is charged with the charge tube 100 tilted at an angle. Furthermore, tilting the charge tube 100 at an angle makes it difficult to put the silicon raw material S into the opening 101a, but by using the raw material charging aid 1 according to this embodiment, it is possible to make it easier to put the silicon raw material S into the charge tube 100 and prevent the silicon raw material S from spilling out. In addition, since it is attached to the opening 101a of the charge tube 100 and guides the silicon raw material S to flow into the charge tube 100, the opening of the charge tube 100 can be widened to make it easier to charge the raw material. Moreover, the slider 10 of the raw material charging aid 1 is provided with a slit 15, and the silicon raw material S falls out through the slit 15 on the way to the charge tube 100, so the charging of silicon fine powder into the charge tube 100 can be prevented.

[0060] Figure 8 is a schematic diagram illustrating the recharging or additional charging process of silicon raw material S.

[0061] As shown in Figure 8, the charge tube 100, which is charged with silicon raw material S, is installed above the quartz crucible 301 in the single crystal pulling apparatus 300 and is used for recharging or additional charging of silicon raw material S. When the silicon raw material S in the charge tube 100 is dropped into the quartz crucible 301 to recharge or additionally charge the silicon raw material S, if the silicon raw material S contains a large amount of silicon fine powder Sb, the silicon fine powder Sb may be carried up by turbulence during the fall of the silicon raw material S and adhere to furnace structures such as the heat shield 302 installed above the quartz crucible 301. If such fine powder separates from the surface it adheres to and is carried up again, and is incorporated into the solid-liquid interface between the silicon single crystal in the process of growth and the silicon melt, it may cause dislocation formation or crystal defects in the silicon single crystal.

[0062] However, in this embodiment, when charging silicon raw material S into the charging tube 100 using the raw material charging aid 1, fine powder is removed from the silicon raw material S as much as possible, so that the amount of fine powder in the charging tube 100 can be reduced as much as possible, and the probability of dislocation formation or crystal defects occurring in silicon single crystals due to the supply of fine powder into the single crystal pulling device 300 can be reduced.

[0063] Figure 9 is a schematic perspective view showing the configuration of the raw material charging aid 1 according to a second embodiment of the present invention. As shown in Figure 9, a feature of this raw material charging aid 1 is that the slider 10 has numerous circular holes 17 instead of slits 15. The other configurations are the same as in the first embodiment. The diameter of the circular holes 17 is preferably 3 to 10 mm. This is because if the diameter of the circular holes 17 is too small, fine powder cannot be removed, and if it is too large, usable silicon particles will also be removed. Thus, since the raw material charging aid according to this embodiment has numerous circular holes 17 formed in the slider 10, it can achieve the same effects as in the first embodiment.

[0064] As described above, the raw material charging aid 1 according to this embodiment is provided with a slider 10 that has multiple through-holes consisting of slits 15 or round holes 17, which allow fine powder contained in the silicon raw material S to fall through the through-holes and remove it, so that only silicon particles of a certain size are sent to the charging tube 100. Therefore, fine silicon powder can be removed using only the conventional charging process without adding a new sorting process.

[0065] The present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention, and it goes without saying that these modifications are also included within the scope of the present invention.

[0066] For example, in the above embodiment, the raw material charging aid 1 consists of a combination of a slider 10 and a back plate 20, but it is also possible to omit the back plate 20 and consist only of the slider 10.

[0067] Furthermore, in the above embodiment, the slider 10 is composed of a main guide portion 11 and a wing portion 12, but it may also be configured in which one or both of the wing portions 12 are omitted. In other words, various shapes can be adopted for the slider 10, and various shapes can also be applied to the back plate 20 to match the slider 10.

[0068] Furthermore, in the first embodiment described above, only a slit 15 was formed as a through-hole in the slider 10, and in the second embodiment, only a round hole 17 was formed as a through-hole. However, it is also possible to use a combination of the slit 15 and the round hole 17 as appropriate. [Explanation of Symbols]

[0069] 1. Raw material charging aid 10 Sliders 11 Main Guide Section 12 Wing section 12L Left wing section (First wing section) 12R Right wing section (2nd wing section) 13 Insertion part 13a Ceiling surface 13b opening 14 Handle 15 Slits (through-holes) 16 Stopper 17. Round hole (through part) 20 Backplates 20a opening 20b Exhaust port 21 Center cover section 22 Wing cover section 22L Left wing cover section 22R Right wing cover section 23 Wall 100 Charge Tubes 101 Charging tube body 101a Opening at the upper end of the charging tube body 101b Opening at the lower end of the charge tube body 102 Flange member 102a Screw hole 102b Support piece 102c through hole 103 Bottom lid 104 Shaft 105 Guide tube 107 Resin cover 110 Carrier Case 200 Vacuum devices 201 Inlet 300 Single Crystal Pulling Apparatus 301 Quartz Crucible 302 Heat shield S Silicon raw material Sa: Silicone granules of the appropriate size Sb Silicone Fine Powder

Claims

1. A material charging aid that is detachably attached to a charging tube for recharging or adding granular silicon raw material into a single crystal pulling apparatus, and for charging the silicon raw material into the charging tube, It consists of a roughly plate-shaped member made of quartz and is equipped with a slider that constitutes a flow path for the silicon raw material, A raw material charging aid is characterized in that the tip of the slider is provided with a tubular insertion portion that is inserted into the opening of the charging pipe, and the slider is provided with a plurality of through-holes that penetrate from the front to the back.

2. The raw material charging aid according to claim 1, wherein the through portion is a slit.

3. The raw material charging aid according to claim 2, wherein the width of the slit is 3 to 10 mm.

4. The raw material charging aid according to claim 1, wherein the through portion is a round hole.

5. The raw material charging aid according to claim 4, wherein the diameter of the aforementioned round hole is 3 to 10 mm.

6. The aforementioned slider is The main guide section consists of an elongated, roughly plate-shaped member with a curved surface, A first wing portion is provided at one end of the main guide portion in the width direction and has a downward sloping surface toward the main guide portion, It comprises a second wing portion provided at the other end of the main guide portion in the width direction and having a downward sloping surface toward the main guide portion, The raw material charging aid according to claim 1, wherein the through-holes are provided in the main guide portion, the first wing portion, and the second wing portion, respectively.

7. The raw material charging aid according to claim 1, further comprising a back plate detachably provided on the back side of the slider, which serves as a tray for receiving raw material powder that falls from the through-hole.

8. The raw material charging aid according to claim 7, wherein the back plate is provided with an exhaust port.

9. A handle is provided on the back of the aforementioned slider. The raw material charging aid according to claim 7, wherein the back plate is provided with an opening through which the handle passes.

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