JP2008087998A - Apparatus for supplying raw material and method for supplying raw material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for supplying a raw material, with which production of a gap between a raw material supply pipe (hopper main body) and a bottom lid can be prevented by adjusting the length of the raw material supply pipe. <P>SOLUTION: The apparatus 1 for supplying a raw material is installed in a single crystal pulling apparatus for supplying a lump material being a lumpy raw material and provided with a nearly cylindrical raw material supply pipe 3 for holding the lump material, a conical bottom lid 5 detachably installed at the lower end opening part of the raw material supply pipe 3, and a support member 7 for suspending the bottom lid 5. The raw material supply pipe 3 has a length adjusting means capable of adjusting the length in the axial direction of the pipe 3. Thereby, it is possible to prevent the production of a gap between the lower end opening part and the bottom lid 5 when the lengths of the raw material supply pipe 3 and the support member 7 in the axial direction are changed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a single crystal pulling apparatus for manufacturing a single crystal ingot, and more particularly to a raw material supply apparatus and a raw material supply method for supplying a polycrystalline raw material.

  A specular wafer used as a substrate for manufacturing a semiconductor device is obtained by slicing a single crystal ingot into thin plate members and grinding and polishing the front and back surfaces thereof. This single crystal ingot can be manufactured by, for example, the Czochralski (CZ) method (including the MCZ method). A general method for producing a single crystal ingot using the Czochralski method will be briefly described below.

  In the Czochralski method, a raw material polycrystalline silicon (polycrystalline raw material) is filled in a quartz crucible installed in a furnace of a single crystal pulling apparatus, and the quartz crucible is heated by a heater provided around the quartz crucible. Polycrystalline silicon is melted to obtain a raw material melt. A single crystal with the same orientation as the seed crystal is grown by immersing a single crystal (seed crystal), which is a seed, and slowly pulling up the seed crystal using the crystal pulling mechanism. Finish into an ingot. Then, the single crystal ingot grown to the required size is taken out of the furnace to complete the production of the single crystal ingot.

  After stopping the heating by the heater, the inside of the single crystal pulling apparatus is cooled, and a new quartz crucible and polycrystalline silicon as a raw material are recharged. Usually, when silicon is cooled below the melting point while the raw material melt remains in the quartz crucible, the quartz crucible is broken due to expansion during solidification of the melt, so that only one single crystal ingot is produced from one quartz crucible. It was not possible to increase the cost. Therefore, after the manufacturing process of one single crystal ingot is completed, the raw material polycrystalline silicon used for manufacturing the next single crystal ingot is prevented without cooling the apparatus and preventing the raw material melt in the quartz crucible from solidifying. There has been proposed a single crystal ingot manufacturing method in which the single crystal ingot is pulled up again by melting the recharged polycrystalline silicon. The following techniques are disclosed for supplying polycrystalline silicon as a raw material.

  For example, in Patent Document 1, a single crystal production apparatus (single crystal pulling apparatus) can be easily taken out and taken out, and a nugget-like and / or granular (hereinafter, collectively referred to as “lumb-like”) raw material is solidified and melted in a crucible. A recharge tube is disclosed that is charged directly to the liquid surface. This recharge tube realizes a supply rate suitable for recharge and can improve the productivity of single crystals by performing recharge smoothly and efficiently in a short time.

  In Patent Document 2, the lamp material is melted and stuck on the bottom lid by heating the lamp material (raw material polycrystalline silicon) caused by radiant heat from the raw material melt, or a bridge is formed by thermal expansion. Thus, a recharging device for a single crystal pulling device that improves the problem of no longer falling is disclosed.

  Furthermore, Patent Document 3 discloses a raw material supply apparatus and a supply method capable of charging a solid raw material evenly and in a large amount in the circumferential direction without causing crystal contamination.

In each disclosed technique, a raw material supply apparatus including a substantially cylindrical raw material supply pipe (also referred to as a hopper main body or a recharge pipe main body) and a conical bottom cover is used, and the recharge pipe is covered with the bottom cover. The raw material polycrystalline silicon is put in, opened and closed by moving the bottom lid up and down, and the raw material polycrystalline silicon in the raw material supply pipe is dropped into the quartz crucible.
Republished WO2002 / 068732 JP 2004-244236 A JP 2006-89294 A

  However, in the single crystal pulling process, since the raw material supply apparatus is inserted into the furnace of the single crystal pulling apparatus in the middle of the melting process of single crystal silicon pulling, the entire raw material supply apparatus is at a high temperature (several hundred degrees). . For this reason, in the raw material supply apparatus, the shaft (wire) etc. that suspends the bottom cover is extended and the bottom cover is lowered, a gap is formed between the raw material supply pipe and the bottom cover, and the polycrystalline silicon in the raw material supply pipe is removed from the gap. There is a risk of falling.

  For example, if the material supply pipe is made of quartz and the shaft is made of metal, the metal generally has a higher coefficient of thermal expansion than quartz, and even if the length is the same at room temperature, the metal shaft is made of the material at high temperatures. It may be longer and longer than the supply pipe, and a gap may be formed between the raw material supply pipe and the bottom cover. For example, if a raw material supply device is suspended in a furnace of a single crystal pulling device, even if it is quickly operated, it takes a certain amount of time, and the temperature of the shaft may rise from 400 ° C to 500 ° C. Is estimated to occur. In this gap, not all of the bulky raw material is necessarily dropped, but it is a granular material, or fragments or small pieces generated by friction between the nugget-like raw materials (hereinafter collectively referred to as “raw material powder”) ) May fall from such a gap. The granular raw material dropped from this gap may splash the melt when dropped into the crucible, and the splashed melt adheres to the in-furnace product and then drops during pulling and adheres to the crystal. May cause dislocation, and may adversely affect single crystal silicon as a future contamination. Also, when such raw material powder (including the above-mentioned broken pieces and granular pieces) falls when the lower end of the raw material supply pipe is above the gate, the dropped raw material powder rides on the gate or gate flange. As a result, there is a risk that the chamber leaks or the gate cannot be opened or closed.

  Here, the raw material powder is a material obtained by pulverizing a raw material solid such as small pieces, granules, granules, etc. of the raw material having a size that can be dropped from the gap between the raw material supply pipe and the bottom cover as described above. It may mean any shape, including spherical shapes, elliptical spheres such as rugby balls. The arithmetic average diameter based on the number when the sphere is approximated may be about 0.1 mm to about 5.0 mm.

Also, the shape index F can be 1 to 10. Here, the shape index is defined as follows. The equivalent sphere diameter (Deq) is obtained from the volume of the raw material powder, and the ratio F to the maximum distance (Lmax) obtained for the shape of the raw material powder is obtained. For example, as shown in FIG. 9, it is obtained as follows.
Sphere with diameter D: Since Deq and Lmax (diameter) are the same, F = Lmax / Deq = 1.
Cube with side D: Lmax is diagonal length, F = √3 / (6 / π) ^1/3 = 1.396.
A square prism with a side of D and a height of 2D: Lmax is the diagonal length, F = √6 / (12 / π) ^1/3 = 1.57.
A cylinder whose height is twice the diameter D: Lmax is the length of the oblique line connecting the upper and lower bases, and F = √5 / 3 ^1/3 = 1.55.
Cone whose height is the same as the diameter D: Lmax is the length along the conical surface, F = √5 / 4 ^1/3 = 1.41.
Flat plate with thickness D, width 4D and length 8D: Lmax is the diagonal length, F = 9 / (192 / π) ^1/3 = 2.28.

  On the other hand, in order to prevent the raw material powder falling etc. from splashing the melt and adhering the melt to the components of the single crystal pulling device, the raw material supply pipe is Furthermore, it will be exposed to high temperature. In this case, it is considered that the angle is about 600 degrees or more. In this case, it is assumed that the generated gap is 10 millimeters or more. Therefore, it may fall to a larger raw material powder or the like, and may cause problems such as liquid splashing more easily.

  This invention is made | formed in view of such a situation, and the raw material supply which prevents generation | occurrence | production of the clearance gap between a raw material supply pipe | tube and a bottom cover by adjusting the axial length of a raw material supply pipe | tube. An object is to provide an apparatus.

  In order to solve the above problems, a raw material supply apparatus according to the present invention includes a substantially cylindrical raw material supply pipe that holds a raw material, a conical bottom lid that is detachably attached to a lower opening end of the raw material supply pipe, A support member that suspends the bottom lid, and the raw material supply pipe includes a length adjusting means.

  More specifically, the present invention can provide the following.

(1) A raw material supply apparatus for supplying a raw material for growing a single crystal, a substantially cylindrical raw material supply pipe for holding the raw material, and a conical bottom provided detachably at a lower opening end of the raw material supply pipe A raw material held in the raw material supply pipe having the lower open end closed by the attachment of the bottom lid is opened by the removal of the bottom lid. The raw material supply pipe is discharged from the lower open end, and the raw material supply pipe is provided with a length adjusting means.

(2) It is possible to provide the raw material supply apparatus according to (1) above, wherein the length adjusting means is a telescopic tube by fitting.

  Here, the telescopic tube by fitting is a substantially cylindrical first tube having an inner diameter of a predetermined size and an outer diameter smaller than the inner diameter that fits into the first tube. An example of this is a telescopic tube made up of a cylindrical second tube. These two tubes can slide (slide) the inside of the first tube and the outside of the second tube to extend and contract the entire length of the tube. In addition, although both of these 1st pipe | tubes and 2nd pipe | tubes can be arrange | positioned below, it is more preferable to arrange | position a 1st pipe | tube below. This is because contamination is less likely to enter the sliding portion between the inside of the first tube and the outside of the second tube.

(3) Providing the raw material supply apparatus according to (1) or (2) above, wherein the length adjusting means is disposed below in the axial length of the raw material supply pipe. it can.

  Here, the downward direction may be lower than at least half of the axial length of the raw material supply pipe. More preferably, it may be lower than 3/4 of the axial length of the raw material supply pipe. In addition, when what is called a stopper is mounted | worn with the said raw material supply pipe | tube, it is preferable that it is below the mounted stopper. It is possible to cancel by adjusting the gap between the bottom lid and the lower opening end of the raw material supply pipe that may be caused by the stopper.

(4) The raw material supply apparatus according to (1) or (2), wherein the length adjusting means is arranged at a central portion in the axial length of the raw material supply pipe. Can do.

(5) Providing the raw material supply apparatus according to the above (1) or (2), wherein the length adjusting means is arranged above the axial length of the raw material supply pipe. it can.

(6) The raw material supply apparatus according to (1) or (2) above, wherein the length adjusting unit includes a mechanical biasing unit.

  Here, the above-mentioned central portion may include a substantially central portion of the length of the raw material supply pipe in the axial direction, and means a portion between about 1/4 to 3/4 of the entire length. it can. In this way, by changing the position having the length adjusting means, it is possible to select a more preferable mechanical biasing means. Here, the mechanical biasing means may mean means other than chemical and electrical means. This is because quartz is mainly used as the material of the member of the length adjusting means, and its environment is likely to become high temperature. Chemical or electrical materials are not necessarily preferable.

(7) The raw material supply apparatus according to the above (1) or (2), wherein the telescopic tube includes a guide member in a telescopic direction.

  Here, examples of the guide member include a rail provided at the sliding portion of the telescopic tube by fitting. Thereby, inadvertent rotation can be prevented and smoother expansion and contraction can be achieved.

(8) A substantially cylindrical raw material supply pipe that holds the raw material for growing a single crystal, a conical bottom cover that is detachably attached to a lower opening end of the raw material supply pipe, and a support member that suspends the bottom cover; A raw material supply method for supplying a raw material using a raw material supply apparatus comprising: a step of filling the raw material supply pipe with the bottom lid attached with the bulk of the raw material; and the raw material supply pipe filled When the raw material supply apparatus including the raw material is suspended in the single crystal growth apparatus by supporting it with the support member, and the axial length ratio of the support member and the raw material supply pipe changes, Adjusting the length of the raw material supply pipe in the axial direction to prevent a gap between the attached bottom lid and the lower opening end, and removing and filling the bottom lid A step of releasing the raw material, Possible to provide a raw material supply method according to symptoms.

  According to the present invention, by adjusting the length of the raw material supply pipe, it is possible to prevent the generation of a gap between the opening at the lower end of the raw material supply pipe and the bottom cover. Thereby, it can prevent that raw material powder etc. fall from the clearance gap which arises between the opening of the lower end part of a raw material supply pipe | tube, and a bottom cover.

  Next, embodiments of the present invention will be described with reference to the drawings. In the drawings, components having the same configuration or function and corresponding parts are denoted by the same reference numerals and description thereof is omitted. Moreover, in the following description, only an example of the embodiment according to the present invention is shown, and can be appropriately changed without exceeding the scope of the present invention based on the common general knowledge of those skilled in the art. Therefore, the scope of the present invention is not limited to these specific examples.

  1A to 1C are cross-sectional views showing an example of a raw material supply apparatus 1 according to the present invention. As shown in FIG. 1A, the raw material supply apparatus 1 includes a substantially cylindrical raw material supply pipe (or hopper body) 3 that holds a raw material (for example, polycrystalline silicon), and a lower end opening of the raw material supply pipe 3. A conical bottom lid 5 that opens and closes 3a and a shaft 7 that suspends the bottom lid 5 are provided. The shaft 7 is further connected to the seed shaft 16 above, and the entire raw material supply device 1 is suspended by a suspension device (not shown). The bottom cover 5 is fixed to the shaft 7 and is attached to the opening 3a at the lower end of the first tube 32, and closes the opening 3a. Further, as will be described later, the lowering of the first pipe 32 is stopped. A cylindrical stopper 71 is caulked and fixed to the metal shaft 7. The first top plate 9 a has a hole through which the shaft 7 is inserted while preventing contamination from entering the raw material supply pipe 3. Further, the bottom cover 5 connected to the shaft 7 is guided so as to be the center of the raw material supply pipe 3. A second top plate 9b is provided fixed to the first top plate 9a. A stopper 71 is provided between the first top plate 9a and the second top plate 9b so as to have a diameter larger than the diameter of each hole opened for inserting the shaft 7. The second tube 31 fixed to the first top plate 9a is suspended by the plate 9b. The locking portion 42a is fixed to the first top plate 9a with a bolt or a clamp-like fastener. The locking portions 42 a have a cylindrical shape extending in the vertical direction, and are provided two symmetrically around the second pipe 31. You may provide three or four in rotational symmetry. Further, the shape is not limited to the cylindrical shape, and three or more simple rod-shaped items may be arranged in an axially symmetrical manner in the circumferential direction. The locking portion 42a is used in an opening / closing mechanism for the bottom lid 5 described later.

  FIG. 1B shows a state where the raw material supply device 1 of FIG. 1A is inserted into the pulling device, the temperature rises, and the metal shaft 7 extends. At this time, the second pipe 31 is also expanded due to thermal expansion, but since the material is quartz, the elongation is remarkably small, and the second pipe 31 is handled as not being shown in this figure. The length of the shaft 7 extends by D as shown in FIG. Therefore, a gap is formed between the opening 3 a at the lower end of the first tube 32 and the bottom cover 5.

  FIG.1 (c) has shown the state which the raw material supply apparatus 1 of FIG.1 (b) closed the clearance gap automatically. That is, the first pipe 32 moves downward by its own weight, and shows a state where the gap is automatically closed and the bottom cover 5 is mounted again from the state shown in FIG. As can be seen here, the length of the overlapping sliding portion of the first tube 32 and the second tube 31 is shortened by D, and D which has been extended due to a difference in thermal expansion or the like is absorbed. Therefore, it is preferable that such a sliding part secures more than the expected elongation.

  Here, the bottom lid 5 has a bottom diameter that is substantially the same as or slightly larger than the diameter of the second tube 32. A part of the conical surface of the bottom cover 5 engages with the lower end of the first pipe 32 to close the lower end opening 3 a of the hopper pipe 5.

  Thus, the raw material supply pipe 1 having the length adjusting mechanism that adjusts the overall length prevents the raw material supply apparatus 1 from generating a gap between the raw material supply pipe 3 and the bottom cover 5. Can do. Thereby, it can prevent that raw material powder falls from the clearance gap which arises between the raw material supply pipe | tube 3 and the bottom cover 5. FIG.

  FIGS. 2A to 2D are vertical sectional views showing an example in which the ratio of the lengths of the second pipe 31 and the first pipe 32 constituting the raw material supply pipe 3 is changed. 2A shows a case where the length adjusting mechanism is provided below, FIG. 2B shows a case where the length adjusting mechanism is provided in the middle, and FIG. It is a figure which shows the example at the time of providing in. The length adjusting mechanism can prevent a gap from being generated between the raw material supply pipe 3 and the bottom cover 5, and can also obtain the following effects depending on the position where the length adjusting mechanism is provided. In FIG. 2A, it is possible to prevent the weight of the first tube 32 applied to the bottom cover 5 from becoming excessively heavy. In FIG.2 (b), the weight of the 1st pipe | tube 32 concerning the bottom cover 5 can be made sufficient, and it can be made hard to leave a clearance gap.

  In FIG.2 (c), the weight of the 1st pipe | tube 32 concerning the bottom cover 5 can be made still more enough, and a clearance gap can be made harder. Moreover, since an internal diameter becomes large, more raw materials can be filled.

  In FIG. 2D, similarly to FIG. 2C, the weight of the first tube 32 applied to the bottom lid 5 is further increased, and more raw material can be filled. In this embodiment, the locking portion 42 is fixed to the first pipe 32 with a belt or the like. Accordingly, the opening timing is slightly different from the case of FIGS. 2A to 2C. That is, when the lowering of the first pipe 32 is locked by the locking portion 42, the length adjusting mechanism does not function, so that the loading / unloading of the bottom lid 5 is not delayed.

  Next, based on FIG. 3, the whole structure of the single crystal pulling apparatus 10 which pulls the single crystal silicon to which the raw material supply apparatus 1 which is an example of embodiment of this invention is applied is demonstrated easily. FIG. 3 represented by a cross section shows a state in which the raw material supply device 1 is installed in the furnace of the single crystal pulling apparatus 10 during the melting process of single crystal silicon pulling. A single crystal pulling apparatus 10 shown in FIG. 3 mainly includes a chamber 12 and a subchamber 14. In the chamber 12, a heat insulating material 26 surrounding the quartz crucible 20, the graphite crucible 22, and the heater 24 is disposed. The sub-chamber 14 is provided in the upper part of the chamber 12 with a gate valve 18 that can open and close the opening 18a. In the crystal growth step, the single crystal is pulled from the raw material melt 48, separated, and then a single crystal ingot. Is used to hold and take out the single crystal pulling apparatus 10. The seed shaft 16 latches a seed crystal (not shown) or the raw material supply apparatus 1.

  First, the chamber 12 will be described. As shown in FIG. 3, the bottomed cylindrical chamber 12 is provided with a rotary shaft 28 that can move up and down with the rotary shaft directed vertically upward from the center of the bottom. A bowl-shaped graphite crucible 22 is fixed to the upper end of the rotating shaft 28, and a bowl-shaped quartz crucible 20 is fitted inside the graphite crucible 22. The double structure of the quartz crucible 20 and the graphite crucible 22 is because the crucible directly in contact with the raw material melt is preferably the quartz crucible 20 in order to prevent contamination of silicon. On the other hand, quartz is softened at a high temperature and has a property of being brittle and easily damaged, and therefore, the periphery thereof is surrounded by a graphite crucible 22.

  The graphite crucible 22 is surrounded by a heater 24, and the heater 24 melts the polycrystalline silicon lamp material 46 put into the quartz crucible 20. A cylindrical heat insulating material 26 is disposed around the heater 24 concentrically with the chamber 12. The heat insulating material 26 prevents heat from the heater 24 from being directly radiated to the chamber 12.

  As shown in FIG. 3, a substantially cylindrical sub-chamber 14 is connected to the upper portion of the chamber 12 via a gate valve 18. The chamber 12 and the sub-chamber 14 can be communicated or blocked by the gate valve 18. On the other hand, although not shown, the upper end of the sub-chamber 14 is sealed with a top plate. Further, as shown in FIG. 3, a ring-shaped flange portion 40 that protrudes toward the central axis is provided on the inner peripheral surface of the sub-chamber 14.

  A seed shaft pulling device (not shown) is provided on the upper portion of the sub chamber 14. The seed shaft lifting device holds the seed shaft 16 so as to be movable up and down, and is suspended along the central axis of the subchamber 14. A seed crystal is suspended from the lower end of the seed shaft 16 during the single crystal ingot pulling process, and the raw material supply apparatus 1 is suspended during the raw material supply process.

  Next, the structure of the raw material supply apparatus 1 that is hooked on the seed shaft 16 in the raw material supply process will be described. A shaft 7 is coupled to the seed shaft 16, and the shaft 7 is coupled to the bottom lid 5 through a hole formed in the second top plate 9 b and the first top plate 9 a. As described with reference to FIG. 1, the raw material supply pipe 3 composed of the second pipe 31 and the first pipe 32 is ultimately formed by the shaft 7 by the stopper 71 and the bottom cover 5 locked to the second top plate 9 b. Retained.

  The second tube 31 and the first tube 32 are made of quartz in order to prevent contamination of silicon as a raw material so as not to contaminate a silicon single crystal as a product. Further, by configuring the second tube 31 and the first tube 32 with transparent quartz, it is possible to confirm whether or not all of the polycrystalline silicon lamp material 46 loaded in the raw material supply apparatus 1 has fallen. it can. Further, the first top plate 9a is hooked on the flange portion 40, and the locking portion 42a for stopping the lowering of the second pipe 31 is fixed via the first top plate 9a. The locking portion 42a is supported by the flange portion 40, stops the lowering of the first top plate 9a, and stops the lowering of the second tube 31 fixed to the first top plate 9a.

  The first tube 32 slides and descends at the sliding portion with the second tube 31 due to its own weight, and the opening 3 a at the lower end thereof contacts the conical surface of the bottom cover 5. Since the bottom lid 5 is fixed to the shaft 7 and suspended, the bottom lid 5 stops further lowering of the first pipe 32. Here, the opening 3a is closed by the bottom lid 5, but the self-weight of the first pipe 32 works like residual pressure, so that the opening 3a can be reliably closed. The shaft 7 is made of metal (for example, made of stainless steel). As described with reference to FIG. 1, a stopper 71 is fixed to the shaft 7, and a hole for allowing the shaft 7 to pass therethrough is formed between the first top plate 9 a and the second top plate 9 b. Is arranged. In a state where the raw material supply apparatus 1 is suspended, the stopper 71 contacts the second top plate 9b, and the second pipe 31 fixed to the second top plate 9b via the first top plate 9a is provided. The bottom pipe 5 is also restricted from descending the first pipe 32 that is suspended and that is the outer pipe of the fitting type double pipe.

  FIG. 4 shows a state in which the raw material supply is started. When supplying polycrystalline silicon as a raw material, first, the gate valve 18 (see FIG. 3) is opened, and the chamber 12 and the sub-chamber 14 become one space. At this time, heat is applied from the melt 48 in the crucible 20 by radiation, and the temperature of the raw material supply apparatus 1 rises. Further, the entire raw material supply apparatus 1 is lowered, the locking portion 42a is supported by the flange portion 40, and the lowering of the second pipe 31 is stopped via the first top plate 9a. Furthermore, by lowering the shaft 7 without lowering the position of the second pipe 31, the bottom cover 5 is finally attached and detached, and the opening 3a at the lower end of the first pipe 32 is opened. If there is room for sliding in the sliding portion between the first tube 32 and the second tube 31, first, the first tube 32 descends due to the weight of the first tube 32, and the bottom cover 5 is attached and detached. Delayed (Figure 5).

  However, when the shaft 7 is further lowered, the bottom cover 5 is detached from the opening 3a, the opening 3a at the lower end of the first tube 32 is opened, and the raw material melt of the quartz crucible 20 is supplied from the raw material supply device 1. Lumped polycrystalline silicon is supplied to 48. At this time, the first flange 32 a of the first pipe 32 is supported by the second flange 31 a of the second pipe 31. In the present embodiment, the bottom cover 5 continues to descend, while the lowering of the raw material supply pipe 3 (second pipe 31 and first pipe 32) is stopped, thereby opening the opening 3a. However, conversely, the lowering of the bottom lid 5 can be stopped and the raw material supply pipe 3 can be raised. That is, the opening 3a can be opened and closed by the relative movement of the two.

  By the way, when the raw material supply apparatus 1 is installed in the sub-chamber 14 in a high temperature state, or when the raw material supply apparatus 1 installed in the sub-chamber 14 descends and moves into the chamber 12, the raw material supply apparatus 1 You will be exposed to high temperatures. In particular, when the gate valve 18 is open, the temperature easily rises due to radiant heat from the crucible 22 or the like. As a result of the raw material supply apparatus 1 being exposed to a high temperature and the shaft 7 extending as compared with the second pipe 31, the bottom lid 5 is relatively lowered. As described above, if the first tube 32 does not easily descend due to the weight of the first tube 32, a gap may be formed between the lower end opening 3a and the bottom lid 5, as shown in FIG. . In this case, for example, the first tube 32 can be pushed downward by a third tube as will be described later. In addition to this, a similar push-down jig (for example, one or a plurality of vertically provided bars that act on the first flange portion 32a of the first tube 32) is provided, or it is non-contact and acts by magnetism or the like. It is possible to arrange an electromagnetic mechanism or the like to make the generated gap appropriately narrow or eliminate. In the case of FIG. 4, as shown in FIG. 5, the first tube 32 descends in synchronization with the descending of the bottom lid 5, and therefore, between the lower end opening 3 a of the first tube 32 and the bottom lid 5. It is possible to automatically prevent a gap from occurring. Accordingly, the generation of a gap due to thermal expansion is prevented, and the ramp material 46 made of massive polycrystalline silicon filled in the raw material supply pipe 3 (comprising the first pipe 32 and the second pipe 31) or the friction thereof. It is possible to prevent the raw material powder including fragments and small pieces generated by the falling.

  Thus, by providing the raw material supply pipe 3 with the length adjusting mechanism (or length adjusting means), it is possible to prevent a gap from being generated between the raw material supply pipe 3 and the bottom cover 5. Thereby, it is possible to prevent the polycrystalline raw material powder and the like from dropping from the gap formed between the raw material supply pipe 3 and the bottom cover 5, and to avoid the occurrence of problems due to the dropping of the polycrystalline raw material powder and the like. . For example, it is possible to prevent the occurrence of a leak failure caused by adhering to a seal (O-ring) portion of the gate valve 18 or the like. Further, even when the temperature in the furnace of the single crystal pulling apparatus 10 (in the chamber 12 or the subchamber 14) is high, the raw material supply apparatus 1 can be installed in the single crystal pulling apparatus 10, and The raw material supply apparatus 1 can be kept in the single crystal pulling apparatus 10 for a long time with the gate valve 18 opened.

  The raw material supply pipe 3 as a whole must have a predetermined length, but is divided into a second pipe 31 and a first pipe 32 so that the raw material supply pipe 3 has a predetermined length as a whole. A considerable amount can be secured. Therefore, it is not necessary to lengthen the length of one tube in this way, and it is only necessary to manufacture many short tubes, so that productivity is improved particularly in manufacturing a quartz tube or the like.

  7 and 8 show another embodiment in a longitudinal sectional view and an AA-AA sectional view, respectively. Since the basic structure is the same as that of FIG. 2D, a duplicate description is omitted. A third tube 31b is installed outside the second tube 31 so as to be slidable in the vertical direction. The third pipe 31 b is placed on the first flange 32 a of the first pipe 32 and biases the lowering of the first pipe 32.

  FIG. 8 is a cross-sectional view taken along the line AA-AA in FIG. Guide members 31c and 32b extending along the vertical direction are provided on the upper and lower sides in the drawing. Where these are provided, the first flange 32a and the second flange 31a are cut to form an opening 31d, which inhibits relative sliding of the first tube 32 and the second tube 31. It is not intended to slide while tilting or rotating.

  As described above, although not shown in FIGS. 1 to 8, when the load applied to the peripheral portion of the bottom cover 5 is excessive, a heat resistant spring is interposed between the first flange 32a and the second flange 31a. By providing such an elastic body, the load applied to the peripheral portion of the bottom cover 5 can be reduced.

  Furthermore, the length adjustment mechanism of the raw material supply pipe shown in the above embodiment is merely an example, and other means may be used. Other methods may be used as long as the length of the raw material supply pipe is changed in conjunction with the movement of the bottom cover and no gap is generated between the bottom cover and the lower end opening of the raw material supply pipe.

  Moreover, the raw material supply apparatus 1 and the single crystal pulling apparatus 10 shown in the above embodiment are examples, and are not limited to these. The raw material supply apparatus of the present invention can be applied to any apparatus having a function of opening and closing a lower end opening of a raw material supply pipe (hopper body) by attaching and removing a conical bottom lid. In addition, although the above-described embodiment has been described by taking the shape of the material supply pipe of the material supply device 1 as an example of a cylindrical shape, the shape is not limited to the cylindrical shape, and may be other shapes such as a rectangular cylindrical shape. Needless to say, it may be. Further, the shape of the bottom lid is not limited to the conical shape or the truncated cone shape, and it is needless to say that the bottom lid may have another shape such as a pyramid or a prism.

It is sectional drawing which showed the example of the raw material supply apparatus which concerns on this invention. (A) shows the state at normal temperature, (b) shows the state at high temperature, and (c) shows the state when the length adjusting mechanism functions. It is a figure which shows the example which changed the ratio of the length of the 1st pipe | tube and 2nd pipe | tube which comprise a raw material supply pipe | tube. (A) when the first tube is short, (b) when the lengths of the first tube and the second tube are the same, (c) when the first tube is long, (d) An example in which the first tube is long and the locking portion is fixed to the first tube is shown. It is sectional drawing which showed the example of the single crystal pulling apparatus which has arrange | positioned the raw material supply apparatus which is an example of this embodiment. FIG. 4 is a diagram showing the single crystal pulling apparatus of FIG. 3 when the gate valve is opened and the raw material supply apparatus is exposed to a high temperature. FIG. 5 is a cross-sectional view showing a state when a length adjusting mechanism of a raw material supply apparatus which is an example of the present embodiment functions in the single crystal pulling apparatus of FIG. 4. FIG. 5 is a cross-sectional view showing a state in which a raw material supply apparatus as an example of the present embodiment releases a raw material lamp material (bulk polycrystalline silicon) in the single crystal pulling apparatus of FIG. 4. It is sectional drawing which showed another embodiment of the raw material supply apparatus which concerns on this invention. It is the figure which showed AA-AA sectional drawing of FIG. It is explanatory drawing of a figure index.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Raw material supply apparatus 3 Raw material supply pipe 5 Bottom cover 7 Shaft 9a, 9b 1st and 2nd top plate 10 Single crystal pulling apparatus 12 Chamber 14 Subchamber 16 Seed shaft 18 Gate valve 20 Quartz crucible 22 Graphite crucible 24 Heater 26 Heat insulation Material 28 Rotating shaft 31 Second tube 31a Second flange 31b Third tube 31c Guide 32 First tube 32a First flange portion 32b Guide 40 Flange portions 42, 42a Locking portion 46 Lamp material 48 Raw material melt 71 Stopper

Claims (8)

A raw material supply apparatus for supplying a raw material for growing a single crystal,
A substantially cylindrical raw material supply pipe for holding the raw material;
A conical bottom lid detachably provided at a lower opening end of the raw material supply pipe;
A support member for suspending the bottom lid,
The raw material held in the raw material supply pipe having the lower open end closed by the mounting of the bottom lid is discharged from the lower open end opened by the loading and unloading of the bottom lid,
The raw material supply apparatus, wherein the raw material supply pipe includes a length adjusting means.   The raw material supply apparatus according to claim 1, wherein the length adjusting means is a telescopic pipe by fitting.   The raw material supply apparatus according to claim 1 or 2, wherein the length adjusting means is disposed below the axial length of the raw material supply pipe.   3. The raw material supply apparatus according to claim 1, wherein the length adjusting means is disposed at a central portion in the axial length of the raw material supply pipe.   The raw material supply apparatus according to claim 1, wherein the length adjusting unit is disposed above the axial length of the raw material supply pipe.   The raw material supply apparatus according to claim 1, wherein the length adjusting unit includes a mechanical biasing unit.   The raw material supply device according to claim 2, wherein the telescopic tube includes a guide member in a telescopic direction. A substantially cylindrical raw material supply pipe for holding a raw material for growing a single crystal;
A conical bottom lid detachably provided at a lower opening end of the raw material supply pipe;
A raw material supply method for supplying a raw material using a raw material supply device comprising a support member for suspending the bottom lid,
Filling the bulk material into the raw material supply pipe fitted with the bottom lid;
A process of suspending a raw material supply apparatus including the raw material filled in the raw material supply pipe by supporting the raw material supply apparatus in the single crystal growth apparatus with the support member;
When the axial length ratio of the support member and the raw material supply pipe changes, by adjusting the axial length of the raw material supply pipe, the attached bottom lid and the lower opening end are adjusted. A process to prevent gaps between them,
And a step of releasing the filled raw material by removing the bottom cover.

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