JP4103593B2 - Recharge tube for solid polycrystalline raw material and method for producing single crystal using the same - Google Patents

Description

[Technical field]
[0001]
  The present invention relates to a recharge tube for additionally filling a solid polycrystalline raw material when producing a single crystal and a method for producing a single crystal using the same.
[Background art]
[0002]
  A single crystal is a semiconductor single crystal, and here, a silicon single crystal will be described as an example.
[0003]
  A silicon single crystal wafer used as a substrate of a semiconductor integrated circuit is manufactured by pulling up a silicon single crystal by, for example, the Czochralski (CZ) method. In the CZ method, first, polycrystalline silicon (polycrystalline raw material) is filled into a quartz crucible, and the graphite crucible holding the quartz crucible is heated with a cylindrical graphite heater on the outer periphery to melt the polycrystalline silicon. Let Next, after immersing the seed crystal in a silicon melt to form a constricted portion and making it dislocation-free, a silicon single crystal is grown until the required diameter and length are obtained.
[0004]
  In this CZ method, in order to reduce the manufacturing cost of the silicon single crystal, in order to supply the reduced amount of the silicon melt in the crucible accompanying the pulling of the silicon single crystal, a supply pipe is provided to form a granular polycrystalline material into the crucible. There is known an apparatus for supplying (hereinafter referred to as a granular raw material) in accordance with a melt reduction amount. As one of these apparatuses, there is a so-called continuous charge (CCCZ) method in which a single crystal is grown while continuously supplying a granular raw material to a molten metal surface in a crucible during silicon single crystal growth. The manufacturing cost can be greatly reduced. The additional filling of the polycrystalline raw material is referred to as recharging.
[0005]
  However, in this method, it is necessary to slowly supply a small amount of granular raw material in the same amount as the silicon single crystal growth amount (usually about 0.3 g / second to 1.0 g / second). In many cases, the molten metal jumps at the time of supply or causes disturbance such as vibration of the molten metal surface. For this reason, the silicon single crystal undergoes dislocations during the growth of the silicon single crystal, making it impossible to continue the growth of the silicon single crystal, and it is often impossible to reduce the manufacturing cost. In order to prevent this, the supply rate is suppressed to some extent by narrowing the tip of the supply pipe. This has the disadvantage that the supply speed is limited and the supply time of the granular raw material becomes too long.
[0006]
  Furthermore, if a crucible with a double structure is used to prevent the growth of the silicon single crystal from being hindered by continuous supply of granular raw materials, the interface of the silicon single crystal is close to the inner crucible, so that oxygen is reduced. There is a disadvantage that it cannot be performed, and there is a problem that the structure becomes complicated and the cost of the crucible increases.
[0007]
  In addition, as a method for reducing the manufacturing cost when adding raw materials in a conventional batch method, a multi-pooling (or recharge pulling (RCCZ)) method is known (Fumio Shimura, Semiconductor Silicon Technology, p178-p179, 1989). In this method, after pulling up a silicon single crystal having a dopant concentration in a range that satisfies the resistance standard, a rod-shaped polycrystalline material (hereinafter referred to as a rod-shaped material) corresponding to the pulled weight is suspended to form quartz. While immersing in the silicon melt remaining in the crucible, it is gradually melted and refilled, and by repeatedly pulling up the same silicon single crystal again, multiple silicon single crystals can be used from a quartz crucible that can only be used once. In order to improve the manufacturing yield, the cost of the quartz crucible is reduced.
[0008]
  However, in the RCCZ method, since the raw material is suspended from the pulling wire, the raw material cannot be supplied until after the silicon single crystal is taken out. Therefore, there is a problem that the raw material supply and the silicon single crystal cannot be taken out in parallel. In addition, there are drawbacks such as long melting time, large melting of the quartz crucible, and heavy metal concentration. From the viewpoint of growing high-purity silicon single crystals, impurities in the melt are deposited. The number of pull-ups is limited.
[0009]
  On the other hand, as the recharge method, after pulling up the silicon single crystal, the surface of the silicon melt remaining in the crucible is solidified once, and then the raw material is supplied into the crucible from the supply pipe provided on the quartz crucible on the surface. A method of recharging is disclosed (Japanese Patent Laid-Open No. 62-260791). In this method, it is described that the material supply and the silicon single crystal can be taken out in parallel, the working time is shortened, and the working efficiency is good.
[0010]
  From the above situation, the shorter the raw material supply time, the shorter the silicon single crystal manufacturing time and the higher the productivity of the silicon single crystal. Therefore, the raw material supply speed is high as long as the quartz crucible is not damaged. Moderate. For this reason, as raw materials used for recharging, raw materials that can be supplied in large quantities at a time, such as rod-shaped raw materials and massive polycrystalline raw materials (hereinafter referred to as nugget-shaped raw materials), have been generally used.
[0011]
  By the way, in the apparatus disclosed in Japanese Patent Laid-Open No. Sho 62-260791, it is necessary to attach a raw material container, a gate valve, a raw material supply pipe, a vacuum pump for decompression, etc. that can be decompressed to a conventional silicon single crystal manufacturing apparatus. A large expense is required for remodeling the crystal production equipment and manufacturing a series of raw material supply equipment. In addition, since ancillary devices such as a crystal diameter detector and a melt temperature detector are attached to the upper part of the main chamber of a recent silicon single crystal manufacturing device, there is a problem that the raw material supply device cannot be easily attached. there were.
[0012]
  In recent years, in order to improve device performance, yield, and the like, higher quality of silicon single crystal as a material has been demanded. In order to obtain a high-quality silicon single crystal, the applicant of the present application provided a colored heat-shielding cylinder in the silicon single crystal manufacturing apparatus (Japanese Patent Publication No. 06-039351) and provided a heater inside. Providing a cylinder (Japanese Patent No. 2785623) has been proposed. In the case where the silicon single crystal manufacturing apparatus has a structure including a heat shielding member so as to cover the upper surface of the melt surface, when the raw material supply apparatus is attached to supply the polycrystalline raw material into the crucible, There has been a problem that the shielding member becomes an obstacle and it becomes difficult to supply the polycrystalline raw material.
[0013]
  On the other hand, when the nugget raw material is filled in the quartz crucible, the nugget raw material is at room temperature. was there. Also, if the melt surface is solidified to prevent the splash of the melt, depending on the progress of solidification, the quartz crucible is damaged and the inner surface of the quartz crucible is peeled off, and the peeled quartz scraps are growing. There is a problem that the phenomenon that the silicon single crystal is attached to the silicon single crystal and dislocation occurs in the silicon single crystal to be polycrystallized frequently occurs, thereby greatly reducing the production efficiency of the silicon single crystal. Furthermore, if solidification proceeds excessively, there is a problem that the quartz crucible cracks and the melt in the quartz crucible leaks to the outside.
[0014]
  Therefore, in view of the above-mentioned conventional problems, the object of the present invention is to easily take in and out of a single crystal manufacturing apparatus without attaching the conventional raw material supply apparatus, and in the form of nuggets and / or grains (hereinafter referred to as solid forms). Single-crystal productivity can be achieved by supplying raw materials directly to the solidified melt surface in the crucible, achieving a supply rate suitable for recharging, and performing recharging smoothly and efficiently in a short time. It is an object of the present invention to provide an inexpensive solid polycrystalline raw material recharge tube.
[0015]
  Another object of the present invention is to provide a method for producing a single crystal capable of producing a dislocation-free single crystal safely and efficiently using the recharge tube.
[Disclosure of the invention]
[0016]
DISCLOSURE OF THE INVENTION
  In order to solve the above-described problem, according to one aspect of the present invention, a single crystal manufacturing apparatus having a crucible for storing a crystal melt is detachably provided, and the crucible is filled with a solid polycrystalline raw material. The recharge pipe has a substantially cylindrical recharge pipe main body holding the solid polycrystalline raw material therein, a conical valve detachable at a lower end of the recharge pipe main body, and an upper end of the recharge pipe main body. A lid that is detachably provided and seals the solid polycrystalline raw material to the recharge tube main body, a hook for suspending the recharge tube main body, a recharge tube wire that connects the hook and the conical valve, and the lid And a stopper that is positioned so that the recharge tube wire penetrates substantially the center of the recharge tube main body.In order to support the recharge tube main body in the single crystal manufacturing apparatus, a quartz glass flange portion that is integrally attached to the recharge tube main body and an inner surface of the recharge tube main body are fitted to the lid. A guide to be fixed,And the inner circumference of the recharge tube main body expands outward at an angle of 0.5 to 5.0 ° in a tapered manner toward the lower end.ing.
[0017]
  The recharge pipe of the present invention is a substantially cylindrical recharge pipe filled with a nugget-like raw material, a granular raw material, or a mixed raw material, and is taken into a single crystal manufacturing apparatus in a state where the recharge pipe main body is suspended by a hook. be able to. Then, the conical valve connected to the recharge tube wire is separated from the lower end portion of the recharge tube body, and the solid raw material held in the recharge tube body is filled into the crucible. Here, the solid raw material can fall along the curve or straight line of the recharge tube main body and spread outward (for example, in a tapered shape), and the solid raw material can be smoothly filled without clogging or stagnation. In addition, it can be taken into and out of a single crystal manufacturing apparatus very easily.
[0018]
Also,A flange portion made of transparent or opaque quartz glass is integrally attached to the recharge tube main body at an appropriate position by welding or the like. Optimum position between the recharge pipe and the crucible that supports the flange part and fills the solid raw material at the position of the support ring (support base) that is detachably mounted in the single crystal manufacturing equipment. Can keep a great distance. Moreover, when welding a flange part, it is more preferable to integrate the perimeter by welding so that a solid raw material can be supported even if it becomes heavy.
[0019]
  On the other hand, when the angle of the taper portion is smaller than 0.5 °, the solid raw material, particularly the nugget-like raw material is clogged or stagnated. If it is larger than 5.0 °, the outer diameter of the tapered tip of the quartz tube becomes too large, which is not preferable. When the angle of the tapered portion is 1.0 to 2.0 °, it is more preferable that the effect of uniformly filling the solid raw material and securing of an appropriate outer diameter can be achieved.
[0020]
  In this case, it is preferable that both the recharge pipe main body and the conical valve are made of high-purity transparent quartz glass.
[0021]
  Since both the recharge pipe main body and the conical valve are made of high-purity transparent quartz glass, it is possible to prevent contamination of the bulk material contacting the inner surface.
[0023]
  in this case,SaidThe guide and the stopper are preferably made of tetrafluoroethylene.
[0024]
  By making the guide and stopper made of tetrafluoroethylene, the lid can be attached in close contact with the recharge tube main body, and foreign matter such as dust in the working chamber can be prevented from entering the recharge tube main body from above.
[0025]
  In this case, the diameter of the recharge tube main body is preferably 25 to 60% of the diameter of the crucible.
[0026]
  By setting the diameter (outer diameter) of the main body of the recharge tube to 25 to 60% of the diameter (outer diameter) of the quartz crucible, a recharge tube that is easy to handle and can be filled uniformly and efficiently with a solid material is obtained. . Here, when the diameter of the main body of the recharge tube is smaller than 25% of the diameter of the quartz crucible, the solid raw material that can be held at one time by the recharge tube body is reduced, which is not preferable. On the other hand, if it is larger than 60%, the interval between the outer periphery of the recharge tube and the inner periphery of the quartz crucible becomes narrow, and the space where the raw material can be charged becomes small, which is not preferable.
[0027]
  According to another aspect of the present invention, when filling the solid raw material using the recharge tube, the grown single crystal is taken out from the single crystal manufacturing apparatus,Using a recharge pipe with the inner circumference of the main body tapered outward at an angle of 0.5 to 5.0 ° toward the lower end,Hold solid ingredientsSaidThe recharge tube is incorporated into the single crystal manufacturing apparatus, and the entire surface of the residual melt in the crucible is solidified by lowering the heating power of the heater, and then the heating power of the heater is increased and the recharge tube is placed on the solidified surface. After filling the solid raw material and taking out the recharge tube from the single crystal manufacturing apparatus, all the solid raw material in the crucible is melted, and a single crystal is grown again to grow a plurality of single crystals. When filling the solid raw material with the recharge tube, the surface of the melt is solidified by supporting the recharge tube with a metal support ring (support base) portion detachably provided in the single crystal manufacturing apparatus. And the conical valve at the tip of the recharge pipe are brought into contact with each other by raising the crucible, and then the solid raw material is filled by lowering the crucible.
[0028]
  Here, the heating power (solidification power) of the heater when solidifying the melt surface remaining in the quartz crucible after growing the single crystal is about 40 to 70% of the power (melting power) at the time of raw material melting. After the entire melt surface is solidified, the heating power is increased to the melt power all at once, thereby preventing excessive solidification, reducing damage to the inner surface of the quartz crucible, and removing the quartz chips. It is possible to reduce a phenomenon in which dislocation occurs in the crystal and polycrystallizes. By this operation, dislocation-free single crystals can be produced safely and efficiently.
[0029]
  The support ring can be made of the same quartz glass as the main body of the recharge tube. However, the support ring is likely to be chipped and cracked, and the metal made of metal (for example, stainless steel) has sufficient strength to support the main body of the recharge tube. can get. In addition, it is more preferable that the support ring be detachable in the single crystal manufacturing apparatus because maintenance and repair can be facilitated when the damage or the diameter of the recharge pipe body changes. When the flange portion of the recharge tube is placed on the support ring thus provided, the recharge tube is stationary. Furthermore, the solidified melt surface is brought into contact with the conical valve at the tip of the recharge tube by raising the quartz crucible, the load for hanging the wire of the recharge tube is released, and then the quartz crucible is lowered to lower the solidity in the recharge tube. The shape raw material is smoothly filled on the solidified surface in the quartz crucible.
[0030]
  Furthermore, it is preferable that the solid raw material is additionally filled by repeating the filling operation of the solid raw material by the recharge pipe a plurality of times.
[0031]
  By repeating the series of operations from attaching the recharge pipe to the single crystal production device, filling the solid raw material, and taking out the recharge pipe once or twice within the time until the total amount of the solid raw material that has been charged melts. Even a relatively small-capacity recharge tube can sufficiently charge the raw material.
[BEST MODE FOR CARRYING OUT THE INVENTION]
[0032]
  Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 5, but the present invention is not limited thereto.
[0033]
  As shown in FIG. 1, the recharge tube 20 is attached to a substantially cylindrical quartz tube 21 (recharge tube main body) for holding a solid raw material made of polycrystal silicon and a lower end portion of the quartz tube 21. A conical valve 22, which is detachably provided at the upper end of the quartz tube 21, and a lid 23 for sealing the solid material to the quartz tube 21; A guide 24 for fixing to the tube 21, a hook 26 for suspending the quartz tube 21 on the pulling wire of the silicon single crystal manufacturing apparatus 10, a tungsten recharge tube wire 27 connecting the hook 26 and the conical valve 22, and a lid A stopper 25 which is disposed at the center of the tube 23 and is positioned so that the recharge tube wire 27 penetrates the substantially center of the quartz tube 21; And a flange portion 28 for the quartz tube 21 is supported by the single crystal manufacturing apparatus 10..
[0034]
  The quartz tube 21 is made of high-purity transparent quartz glass, and is formed with a tapered portion 21a that widens toward the lower end. The length L2 of the tapered portion 21a is preferably about 20 to 40% of the full length L1 of the recharge pipe 20. The angle θ1 applied to the tapered portion is preferably 0.5 to 5.0 °, and more preferably 0.5 to 3.0 °.
[0035]
  If the angle θ1 of the tapered portion 21a is smaller than 0.5 °, it is not preferable because the solid raw material, particularly the nugget raw material is clogged or stagnated. On the other hand, if the angle θ1 of the taper portion 21a is larger than 5.0 °, the outer diameter at the tip of the taper portion 21a of the quartz tube 21 increases, and in order to pass through the support ring 12d attached in the single crystal manufacturing apparatus 10, Inevitably, the diameter of the quartz tube 21 is reduced, the inner volume of the quartz tube 21 must be reduced, and the filling amount of the solid raw material is reduced, which is not preferable. Further, when the angle θ1 of the taper portion 21a is increased, it is inevitably necessary to increase the projecting dimension of the flange portion 28 from the quartz tube 21. To solve the strength problem, a thick flange having a large thickness is required. The manufacture of the recharge tube 20 becomes complicated. Furthermore, if the angle θ1 of the tapered portion 21a is larger than 3.0 °, the production cost of the quartz tube 21 becomes expensive, but the effect of preventing the clogging and staying of the solid raw material compared to the case of less than that. I can't expect much improvement. When the angle θ1 of the tapered portion 21a is 1.0 to 2.0 °, the solid raw material can be effectively prevented from clogging and staying, and the internal volume can be reduced and the production cost can be suppressed as much as possible. Become. In consideration of such points, in the present embodiment, the length L2 of the tapered portion 21a is about 30% of the total length L1 of the recharge pipe, and the angle θ1 is 1.15 °.
[0036]
  Here, as an example of the purity of the transparent quartz glass that is the material of the recharge tube 20, Al is 14 ppm (parts by weight, the same applies hereinafter), Ca is 0.4 ppm, Cu is 0.05 ppm, Fe Is 0.2 ppm, K and Li are each 0.6 ppm, Na is 0.7 ppm, Ti is 1.1 ppm, and OH is 5 ppm or less. Needless to say, the purity is preferably smaller than the above-mentioned value. In addition, as an example of physical properties, the density is 2.2 × 103 kg / m 3, the tensile strength is 4.9 × 10 6 kgf / m 2 (4.80 × 10 7 Pa), and the compressive strength is 1.1 × 10 8 kgf / m 2 ( 1.08 × 109 Pa) and the softening point is 1683 ° C.
[0037]
  The diameter (outer diameter) R1 of the quartz tube 21 is designed to be 25 to 60% of the diameter (outer diameter) R11 of the quartz crucible 11a. If it is less than 25%, the solid raw material that the quartz tube 21 can hold at a time decreases, and in this case, recharging may be repeated, but this is not preferable because the number of times of recharging increases. If it is larger than 60%, the solid raw material may be filled in the left and right directions, and the space between the outer periphery of the quartz tube 21 and the inner periphery of the quartz crucible 11a is narrowed, and the space for charging the solid raw material is small. It is not preferable. In the present embodiment, for example, if the diameter R11 of the quartz crucible 11a is 24 inches (0.6096 m), the diameter R1 of the quartz tube 21 is 40%, 9.6 inches (0.2438 m).
[0038]
  The conical valve 22 is made of high-purity transparent quartz glass, and the quartz tube 21 is filled with a solid raw material in a state where the conical valve 22 is mounted and closed at the lower end of the quartz tube 21. The angle θ2 formed by the generatrix of the peripheral surface 22a of the conical valve 22 and the bottom surface 22b is preferably 40 to 70 °.
[0039]
  If the angle θ2 is smaller than 40 °, as shown in FIG. 3, when the recharge tube wire 27 is lowered, the conical valve 22A is likely to be swayed in all directions, and the raw material is unevenly filled. On the other hand, when the angle θ2 is larger than 70 °, as shown in FIG. 4, the total height L11 of the conical valve 22B increases, and when the conical valve 22B is lowered to fill the raw material, the solid raw material falls at a stretch. In some cases, the solidified melt is impacted and the quartz crucible 11a is damaged.
[0040]
  Considering the above, when the angle θ2 is 45 to 60 °, it is possible to reduce both the impact on the quartz crucible 11a when the solid raw material is charged and to fill the solid raw material more uniformly in the quartz crucible 11a. Particularly preferred. In the present embodiment, the angle θ2 of the conical valve 22 is 54 °. In addition, in conjunction with the fact that the quartz tube 21 extends outwardly in a tapered shape, the solid material can be smoothly and uniformly filled into the quartz crucible 11a. Note that the symbol L3 indicates the overall height of the conical valve 22.
[0041]
  The guide 24 is made of tetrafluoroethylene, and is integrally attached to the back surface of the lid 23 by screws 24a as shown in FIG. The quartz tube 21 and the lid 23 are attached in close contact with the guide 24. The guide 24 may be fixedly attached to the upper end of the quartz tube 21 with a screw or the like.
[0042]
  The stopper 25 is made of tetrafluoroethylene, and is attached so that the recharge tube wire 27 penetrates almost the center. The stopper 25 and the recharge tube wire 27 are moved along a notch (not shown) from one place on the circumference of the lid 23 to the center, and are fixed to the approximate center of the lid 23. Accordingly, the recharge tube wire 27 is positioned so as to penetrate substantially the center of the quartz tube 21.
[0043]
  If the stopper 25 is not attached, the recharge tube 20 rolls and the isolation valve 13 (the silicon single crystal manufacturing apparatus 10 uses a pull chamber 12 for taking out the silicon single crystal and a crystal growth furnace 11b centering on the quartz crucible 11a. In some cases, the main chamber 11 may contain the main chamber 11 and the chambers may be blocked by the isolation valve 13 (see FIG. 5). By attaching the stopper 25 to the approximate center of the recharge tube 20, the recharge tube 20 is prevented from rolling, not being out of balance, and being prevented from being tilted down, so that the solid raw material is placed in the quartz crucible 11a. Evenly filled.
[0044]
  The flange 28 is made of quartz glass, and as shown in FIG. 2, an optimum interval P for uniformly filling the solid raw material is maintained between the quartz tube 21 and the quartz crucible 11a. The entire circumference is integrated by welding at an appropriate position so that a high weight can be supported.
[0045]
  Hereinafter, recharge using the recharge tube 20 of the present invention will be further described.
[0046]
  First, the raw material is held in the recharge pipe 20. At this time, only a nugget-like raw material having a high purity and a high dissolution rate is often used as a raw material, but when growing a silicon single crystal that does not require a purity, an inexpensive granular raw material may be appropriately mixed with the nugget-like raw material. In some cases, only granular raw materials are present. Only the nugget-like raw material, the nugget-like raw material, the granular raw material, and the granular raw material may be used.
[0047]
  Then, after the silicon single crystal is taken out from the silicon single crystal manufacturing apparatus 10, the recharge tube 20 holding the solid raw material is taken into the silicon single crystal manufacturing apparatus 10. At this time, the isolation valve 13 is closed and the inside of the main chamber 11 is shut off from the atmosphere. When the recharge pipe 20 enters the silicon single crystal manufacturing apparatus 10, the air in the pull chamber 12 is exhausted, and the recharge pipe 20 can be put into the main chamber 11 while the atmosphere is shut off.
[0048]
  A support ring 12d is disposed above the isolation valve 13 in the silicon single crystal manufacturing apparatus 10. When the flange portion 28 of the recharge pipe 20 is placed on the support ring 12d, a solid material can be charged. . When the solid raw material is charged, only the surface of the silicon melt (residual melt) remaining in the quartz crucible 11a is solidified, and the solidified surface A is filled with the raw material. At this time, when the conical valve 22 is in contact with the solidified surface A, the solid raw material can be filled in the most preferable state, and the solid raw material is filled more smoothly by lowering the quartz crucible 11a.
[0049]
  Here, the entire surface of the remaining melt in the quartz crucible 11a is taken out of the grown silicon single crystal from the silicon single crystal manufacturing apparatus 10 and the recharge tube 20 holding the solid raw material is stored in the silicon single crystal manufacturing apparatus 10. During heating, the heating power of the heater is reduced to about 50% of the power at the time of melting the raw material (melting power). The heating power is increased to the melting power at once after the entire surface of the remaining melt is solidified, thereby preventing the solidification from proceeding excessively. By doing so, it is possible to reduce damage to the inner surface of the quartz crucible 11a, and to reduce the phenomenon that dislocations occur in the single crystal due to the separated quartz scraps and polycrystallize. By this operation, dislocation-free single crystals can be produced safely and efficiently.
[0050]
  When the filling of the solid raw material is completed, the recharge tube wire 27 is wound up, the conical valve 22 is accommodated in the lower end portion of the quartz tube 21, and the recharge tube 20 can be taken out.
[Example]
[0051]
  A quartz crucible 11a having a diameter of 22 inches (55.88 cm) is filled with 100 kg of polycrystalline raw material, the heating power (melting power) of the heater is set to 150 kw, and the polycrystalline raw material is melted, and then 8 inches (20.34 cm) in diameter. A silicon single crystal having a mass of 80 kg was grown and removed from the silicon single crystal manufacturing apparatus 10. Next, the recharge pipe 20 holding 40 kg of the nugget-like raw material is taken into the silicon single crystal manufacturing apparatus 10, and the heating power of the heater (during the operation of placing the flange portion 28 of the recharge pipe 20 on the support ring 12d to be stationary) The solidification power was lowered to 90 kW. Thereafter, the heating power was increased to the melting power immediately after the surface of the remaining melt was solidified and almost the entire surface was solidified. At this time, since the quartz crucible 11a is located below, the quartz crucible 11a is raised to bring the solidified surface A into contact with the conical valve 22 of the recharge pipe 20, and the solidified surface A and the conical valve 22 are brought into contact with each other. Thereafter, the load of the suspended recharge tube 27 was loosened, and the quartz crucible 11a was lowered, so that the nugget-like raw material in the recharge tube 20 was gradually put on the solidified surface A.
[0052]
  After the entire amount of the nugget-like raw material was charged, the recharge tube wire 27 was wound up, the conical valve 22 was accommodated in the lower end of the quartz tube 21, and the recharge tube 20 was taken out from the silicon single crystal manufacturing apparatus 10.
[0053]
  Again, the recharge tube 20 holding 40 kg of the nugget-like raw material is taken into the silicon single crystal manufacturing apparatus 10, and the nugget-like raw material is filled on the unmelted raw material in the same manner as described above. Used as raw material.
[0054]
  Thereafter, a second silicon single crystal having a diameter of 8 inches (20.34 cm) and a mass of 80 kg was grown. Thereafter, the same recharge as described above was performed, and a third silicon single crystal was grown.
[0055]
  The three silicon single crystals that were produced were dislocation-free single crystals, and the inner surface of the quartz crucible 11a was observed after the production was completed, but there were no cracks or chips near the solidified surface. There was no big difference in erosion on the inside.
[0056]
[Comparative Example 1]
  Three silicon single crystals were produced under the same conditions as in the Examples except that the timing of the heating power increase after the residual melt was solidified was after the end of the recharge. The manufactured silicon single crystal had dislocations in the second and third. Since the solidification has proceeded excessively, the inner surface of the quartz crucible 11a is damaged, and the inner surface of the quartz crucible 11a is peeled off in the vicinity of the solidified surface, and the quartz debris floating on the melt surface adheres to the growing silicon single crystal and the silicon single crystal It is thought that the crystal was dislocationized.
[0057]
  From the results of Examples and Comparative Example 1, the surface of the residual melt is solidified, and the heating power is increased to the melt power immediately after almost the entire surface is solidified, so that the dislocation-free silicon single crystal can be safely and efficiently obtained. You can see that it can be produced.
[0058]
[Comparative Example 2]
  The quartz crucible 11a is stopped so that the distance between the conical valve 22 of the recharge tube 20 and the solidified surface A is 4 to 5 cm when the material is charged, and the recharge tube wire 27 is lowered and the quartz crucible 11a is also lowered, thereby producing the nugget-like material. Three silicon single crystals were produced under the same conditions as in the example except for filling. The third silicon single crystal produced had dislocations. When the nugget-like raw material is charged, the nugget-like raw material is filled into the solidified surface A by free fall. The uppermost portion of the nugget-like raw material held in the recharge pipe 20 is about 1 m from the solidified surface A. In this case, the nugget-like raw material may penetrate the solidified surface A to scatter the melt, and the molten water droplets may adhere and solidify at several locations on the inner surface of the quartz crucible 11a. This solidified portion becomes a small protrusion, and silicon oxide that evaporates from the molten metal surface is deposited, and it becomes oxide waste and falls on the molten metal surface. It appears that the silicon single crystal was attached to dislocation.
[0059]
  From the results of the example and the comparative example 2, the nugget-like raw material in the recharge tube 20 is gradually introduced onto the solidified surface A in a state where the solidified surface A and the conical valve 22 are in contact with each other, thereby allowing dislocation-free silicon single-piece. It can be seen that crystals can be produced safely and efficiently.
[0060]
  According to the above-described embodiment of the present invention, when the solid material is filled in the quartz crucible 11a in which the silicon single crystal is grown and the silicon melt is reduced, the solid material is held in the recharge tube 20, The recharge tube 20 can be easily taken into and taken out of the silicon single crystal manufacturing apparatus 10, and the quartz crucible 11a is smoothly filled with the solid raw material. By doing so, a plurality of silicon single crystals are obtained from one quartz crucible. Can be nurtured.
[0061]
  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.
[0062]
  For example, in the above description, the case of manufacturing a silicon single crystal mainly by the CZ method has been described, but the present invention can also be applied to, for example, the MCZ method. That is, it goes without saying that the MCZ method is also effective, and the diameter, length, etc. of the quartz tube 21 can be selected at any time, and is not limited thereto.
[Industrial applicability]
[0063]
  According to the present invention, without attaching the conventional raw material supply device, the recharge tube can be easily taken in and taken out of the single crystal device, and the nugget raw material can be smoothly and efficiently charged into the crucible. Moreover, the recharge pipe | tube which can prevent the contamination of the polycrystalline raw material with which it fills can be provided. Therefore, it is possible to improve the productivity of single crystals by realizing a supply rate suitable for recharging and performing recharging smoothly and efficiently in a short time, and an inexpensive solid polycrystalline raw material recharging tube, and its recharging It is possible to provide a method for producing a single crystal that can safely and efficiently produce a dislocation-free single crystal using a tube. Therefore, the solid polycrystalline raw material recharge tube and the method for producing a single crystal using the solid polycrystalline raw material of the present invention are particularly suitable for the production of a single crystal using the solid polycrystalline raw material.
[Brief Description of Drawings]
[0064]
[FIG.]It is a schematic sectional drawing which shows the recharge pipe | tube 20 of the solid raw material of this invention.The
[FIG.]FIG. 2 is a schematic cross-sectional view showing a polycrystalline crucible filled with a polycrystalline raw material using the polycrystalline raw material recharging apparatus of the present invention.The
[FIG.]Is a schematic cross-sectional view showing a polycrystalline crucible filled with a polycrystalline raw material using a recharging device with a different conical valve.The
[FIG.]Is a schematic cross-sectional view showing that a quartz crucible is filled with a polycrystalline raw material using a recharging device having a further different conical valve.The
[FIG.]FIG. 4 is a schematic cross-sectional view showing a polycrystalline crucible filled with a polycrystalline raw material using a recharging device not equipped with a stopper.

Claims (6)

A recharge tube provided in a single crystal production apparatus having a crucible for storing a crystal melt so as to be removable, and for filling the crucible with a solid polycrystalline raw material,
A substantially cylindrical recharge tube body holding the solid polycrystalline raw material therein;
A conical valve detachable from the lower end of the recharge pipe body;
A lid that is detachably provided at an upper end of the recharge tube body, and seals the solid polycrystalline raw material to the recharge tube body;
A hook for suspending the recharge pipe body;
A recharge tube wire connecting the hook and the conical valve;
A stopper provided at the center of the lid, and positioned so that the recharge tube wire penetrates substantially the center of the recharge tube body ;
In order to support the recharge tube main body in the single crystal manufacturing apparatus, a flange portion made of quartz glass attached integrally with the recharge tube main body,
A guide for fitting to the inner surface of the recharge tube main body and fixing the lid is provided,
A solid polycrystalline raw material recharge tube characterized in that the inner periphery of the recharge tube main body is expanded outward at an angle of 0.5 to 5.0 ° in a tapered manner toward the lower end. .   2. The solid polycrystalline raw material recharge tube according to claim 1, wherein both the recharge tube main body and the conical valve are made of high-purity transparent quartz glass. 3. The solid polycrystalline raw material recharge tube according to claim 1, wherein the guide and the stopper are made of tetrafluoroethylene. Solid polycrystalline material recharge pipe as set forth in claim 1, wherein any one of the third term, characterized in that 25 to 60% of the diameters of said crucible of the recharge pipe body. When filling the solid raw material using the recharge tube, the grown single crystal is taken out from the single crystal manufacturing apparatus, and the inner circumference of the main body is tapered to the lower end portion in a taper shape of 0.5 to 5.0 °. angle with recharge tube flares outwardly at the, incorporating the recharge tube holding a solid raw material in the single crystal manufacturing apparatus, lowering the heating power of the entire surface heating of the remaining melt in the crucible The solid material in the recharge tube is filled on the solidified surface while raising the heating power of the heater after solidifying by the above, and after the recharge tube is taken out from the single crystal manufacturing apparatus, the solid material in the crucible is All are melted and a single crystal is grown again to grow multiple single crystals.
When filling the solid raw material with the recharge tube, the recharge tube main body is supported by a metal support ring portion detachably provided in the single crystal manufacturing apparatus, and the solidified melt surface and the A method for producing a single crystal, comprising: bringing a crucible valve at a tip portion of a recharge pipe into contact with a crucible by raising the crucible, and then filling the solid raw material by lowering the crucible. The method for producing a single crystal according to claim 5, wherein the solid raw material is additionally filled by repeating the filling operation of the solid raw material by the recharge pipe a plurality of times.

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