JP4563951B2 - Solid material recharging equipment - Google Patents

Description

  The present invention relates to a solid-state raw material recharging apparatus when a single crystal is produced by the Czochralski (CZ) method.

A so-called Czochralski (CZ) method is known as a method for producing a single crystal, for example, a silicon single crystal. In this method, a solid silicon raw material is housed in a crucible installed in a growth furnace, and the heater is heated to a high temperature to use the raw material in the crucible as a melt. Then, a seed crystal is deposited on the surface of the raw material melt, and a single crystal having a desired diameter and quality is grown below the seed crystal.
However, even when a solid silicon raw material is accommodated in the crucible without any gap before the silicon single crystal is grown, the silicon raw material is melted so that there is no gap, and there is always a slight margin in the crucible volume. Generally, since the crucible used at the time of crystal growth by the CZ method is disposable, it has been well known that, as the weight of the crystal grown by one crucible is increased, the overall cost is reduced. However, it has already reached the limit to increase the silicon raw material when initially storing the solid silicon raw material in the crucible. Therefore, a method is proposed in which the solid silicon raw material is first melted and then the solid silicon raw material is additionally supplied to the silicon melt to effectively use the volume of the crucible, thereby increasing the weight of the crystal to be grown. It has been. This technique is called a recharge technique.

  Conventionally, a single pulling operation in which one single crystal is pulled in one operation is widely used. However, a multi-pulling operation in which a plurality of single crystals are pulled is gradually applied by applying the above-described recharge technology. It tends to increase. That is, for example, after pulling up one silicon single crystal, a solid silicon raw material is additionally supplied to the reduced silicon melt to pull up the second and subsequent silicon single crystals. Such a multi-drawing operation also produces a plurality of single crystals from a crucible that can be used only once, improving the yield of single crystals, and effectively using expensive crucibles to reduce single crystal production costs. The purpose is that.

Among these recharge technologies for additionally supplying a solid silicon raw material onto a silicon melt, a recharge tube recharge method is known as one of the technologies attracting attention from the viewpoint of practicality (for example, Patent Document 1).
FIG. 9 is a schematic longitudinal sectional view for explaining a silicon single crystal manufacturing apparatus used in the conventional recharge tube recharging method. As shown in FIG. 9, the silicon single crystal manufacturing apparatus 100 is provided with a recharge device. The recharge apparatus includes a cylindrical raw material container 200 including a straight-type recharge pipe 201 filled with a solid silicon polycrystalline raw material 155, a wire 129 for suspending the cylindrical raw material container 200, a wire A pulling motor 141 that winds 129 is formed. The wire 129 passes through the center of the raw material container 200 and is fixed at the center of the bottom lid 203 of the raw material container 200. The entire raw material container 200 is held by the bottom lid 203 supporting the lower end of the recharge pipe 201.
The solid silicon polycrystal raw material 155 filled in the recharge tube 201 is lowered by the raw material container 200 toward the quartz crucible 101, and a fringe in which a stopper 205 is provided on the inner wall of the subchamber 127 as shown in FIG. After being latched by 128, only the bottom lid 203 is further lowered to form a gap 210, whereby the quartz crucible 101 is supplied to the silicon melt surface.

However, in the recharge apparatus having such a straight type recharge tube, the wire 129 is pressed and fixed by the solid polycrystalline silicon raw material 155 expanded by high heat in the chamber 111, and the bottom lid 203 does not descend. was there.
Further, the wire 129 is formed of a metal such as tungsten. However, the friction between the wire 129 and the solid polycrystalline silicon raw material 155 causes the metal to adhere to the solid polycrystalline silicon raw material 155, resulting in metal contamination. There was also a problem.

  In order to solve the former problem, the recharge is quickly completed before the temperature of the solid polycrystalline silicon raw material 155 rises, or the amount of the solid polycrystalline silicon raw material 155 at the time of one recharging is reduced. Thus, a method of reducing the contact between the wire 129 and the solid polycrystalline silicon raw material 155 has been taken. However, in the former case, workability is improved in that the heating time for melting the solid polycrystalline silicon raw material 155 in the crucible 101 is increased, and in the latter case, the required number of recharges is increased. It was getting worse.

  Therefore, in Patent Document 2, it is proposed that the recharge tube has a trumpet shape that expands outward toward the lower end portion to facilitate the dropping of the solid polycrystalline silicon raw material 155. However, the maximum lower end inner diameter of the recharge tube is restricted by the inner diameter of the radiation shield 125. However, the shape spreading in a trumpet shape toward the lower end is not always preferable because the inner capacity of the raw material container 200 is reduced as a result. Further, it cannot be a means for solving the aforementioned metal contamination.

In order to solve these problems, Patent Document 3 discloses an invention in which a substantially cylindrical quartz tube integrally formed to cover the wire 129 is provided.
JP 57-95891 A Japanese Patent Publication No. 2002-068732 JP 2004-244236 A

  However, in the method of Patent Document 3, when the solid polycrystalline silicon raw material 155 falling in the recharge tube 201 is unevenly distributed, the substantially cylindrical quartz tube covering the wire 129 may be damaged due to stress concentration. . In addition, the uneven distribution of the silicon solid polycrystalline silicon raw material causes an uneven force on the bottom lid, and the unreasonable force concentrates near the base between the quartz bottom lid and the integrally formed quartz glass rod. There is a risk of damage. In order to avoid this, a flexible structure such as a wire is desirable. In order to avoid breakage, it is possible to increase the strength of the quartz glass rod integrally formed with the quartz bottom lid, but this increases the volume occupied in the recharge tube of the structure. Therefore, the amount of solid polycrystalline silicon raw material stored in the recharge tube is reduced, which is not preferable.

  The present invention has been made in consideration of the above circumstances, and the object thereof is to eliminate friction between the solid raw material and the wire, reduce damage to the member covering the wire or the bottom cover, and An object of the present invention is to provide a solid state material recharging apparatus capable of realizing a high yield and quality in the production of a single crystal by not accompanied by a significant decrease in the amount of solid state polycrystalline silicon material in the recharge tube.

A recharge device according to one embodiment of the present invention includes:
A cylindrical raw material container filled with a solid raw material to be supplied to the crucible storing the crystal melt, and a wire for suspending the cylindrical raw material container whose one end is fixed to the center of the bottom lid of the cylindrical raw material container; A solid-state raw material recharging device comprising:
A solid material recharging apparatus, wherein the wire penetrates a plurality of elliptical or substantially spherical balls made of quartz.

  Here, it is desirable that the oval or substantially spherical ball is made of high-purity quartz glass having a metal impurity content of 200 ppm or less.

  Here, it is desirable that the recharge pipe constituting the cylindrical raw material container is cylindrical and has a straight shape with a constant inner diameter from the upper end to the lower end.

Here, it is desirable that the weight W (g) of the bottom cover satisfies the relationship of W ≧ 3πR ² when the inner diameter of the recharge pipe constituting the cylindrical raw material container is 2R (cm).

  According to the present invention, the friction between the solid raw material and the wire is eliminated, the damage to the member covering the wire or the bottom cover is reduced, and the solid polycrystalline silicon raw material in the recharge tube is greatly reduced. By not having this, it is possible to provide a solid material recharging device capable of realizing high yield and quality in single crystal production.

  Embodiments of a recharging device and a recharging method according to the present invention will be described below with reference to the accompanying drawings. Here, a case where a silicon single crystal is manufactured as a single crystal will be described as an example.

[Embodiment]
(Recharge device)
First, the configuration of a silicon single crystal manufacturing apparatus provided with a recharging apparatus used in the present embodiment will be described.
FIG. 1 is a schematic longitudinal sectional view of a silicon single crystal manufacturing apparatus used in the present embodiment.
The silicon single crystal manufacturing apparatus shown in FIG. 1 has crucibles 101 and 103 filled with polycrystalline silicon as a raw material, a main heater 107 for heating and melting polycrystalline silicon to form a silicon melt 105, and a lower heater 109. Is stored in the chamber 111.

The crucibles 101 and 103 are composed of a quartz crucible 101 that directly accommodates the silicon melt 105 on the inside and a carbon crucible 103 for supporting the quartz crucible 101 on the outside. The crucibles 101 and 103 are supported by a crucible shaft 113 that can be rotated up and down by a rotational drive function (not shown) attached to the lower part of the silicon single crystal manufacturing apparatus.
A main heater 107 and a lower heater 109 are disposed so as to surround the crucibles 101 and 103, and the heat from the main heater 107 is prevented from being directly radiated to the chamber 111 outside the main heater 107. A first heat insulating material 115 and a second heat insulating material 117 are provided so as to surround the main heater 107. In addition, a third heat insulating material 119 and a fourth heat insulating material 121 for preventing heat from the silicon melt 105 and the crucibles 101 and 103 from being directly radiated to the chamber 111 are provided. A radiation shield 125 is provided between the silicon melt 105 and the crucibles 101 and 103 and the silicon single crystal so that heat from the silicon melt 105 and the crucibles 101 and 103 is not pulled up and hinders cooling of the silicon single crystal. . In addition, about the material of the heat insulating materials 115 and 117, it is desirable to use the thing especially excellent in heat retention property, and the shaping | molding heat insulating material is normally used. As the material of the heat insulating materials 119 and 121, for example, a molded heat insulating material, carbon, or a material whose surface is covered with silicon carbide is used. About the radiation shield 125, since it plays the role which adjusts a radiant heat, it is a metal with high heat insulation, for example, metal, such as molybdenum, tungsten, and tantalum, carbon, the surface of carbon covered with silicon carbide, and the inside The one provided with a molded heat insulating material is used.

The chamber 111 is made of a metal having excellent heat resistance and thermal conductivity, such as stainless steel, and is water-cooled through a cooling pipe (not shown).
Further, a sub chamber 127 for holding and taking out a silicon single crystal pulled up from the silicon melt 105 and a cylindrical raw material container 200 described later is provided at the upper portion of the chamber 111 through a gate valve 135. Further, the upper end of the sub chamber 127 is sealed with a top plate 147. A sub-chamber lid (not shown) is provided on the upper side surface of the sub-chamber so that the pulled silicon single crystal can be taken out or a raw material container 200 described later can be taken out.
A pulling motor 141 is provided above the sub chamber 127. The pulling motor 141 holds the wire 129 so as to be movable up and down, and the wire 129 is suspended along the central axis of the sub-chamber 127 through the top plate. At the lower end of the wire 129, a seed crystal 131 is suspended as shown in FIG. 3 during the silicon single crystal pulling process, and as shown in FIG. Can be hung.

Next, the recharging device will be described. First, in the recharging apparatus that can be used in the present invention, as shown in FIG. 1, a cylindrical raw material container 200 is suspended from a pulling motor 141 by a wire 129. The raw material container 200 includes a recharge pipe 201, a bottom cover 203, and a ring 204 through which a wire 129 passes in order to stabilize the recharge pipe 201 on the central axis of the sub chamber 127. The wire 129 is fixed to the center of the bottom cover 203, and the recharge tube 201 is held by the bottom cover 203.
Here, the wire 129 can be bent and deformed by itself when the solid polycrystalline silicon raw material 155 drops when it falls inside the recharge tube 201, and can absorb the shock. From the viewpoint of having sufficient tensile strength to hold the weight of the solid polycrystalline silicon raw material 155 to be filled, a metal material such as tungsten is used.
In addition, a stopper 205 is provided on the outer periphery of the upper portion of the recharge tube 201 for latching the recharge tube 201 with a flange 128 provided in the sub chamber 127. The stopper 205 is preferably made of high-purity quartz glass from the viewpoint of avoiding impurity contamination of the silicon melt 105.

In the present embodiment, it is desirable that the recharge pipe 201 has a straight shape with a constant inner diameter from the upper end to the lower end. This is because the maximum lower end inner diameter of the recharge pipe 201 is restricted by the inner diameter of the radiation shield 125, so that the recharge pipe 201 has a straight shape rather than a shape that spreads in a trumpet shape toward the lower end. This is because the content is increased. On the other hand, the shape that narrows toward the lower end is because the risk of the solid polycrystalline silicon raw material 155 becoming clogged in the recharge tube 201 is rapidly increased.
Here, since the recharge tube 201 and the bottom cover 203 are close to the silicon melt 105, it is preferable that the recharge tube 201 and the bottom cover 203 have excellent heat resistance and do not contaminate the wafer. Although preferable, silicon carbide, silicon nitride, or the like can be used.

  In the present embodiment, a plurality of substantially spherical balls formed of quartz penetrate the wire 129. As shown in FIG. 2, a hole 405 larger than the diameter of the wire 129 is formed to pass the wire 129 through a substantially spherical ball 401 made of quartz. As shown in FIG. 1, a plurality of the substantially spherical balls 401 passed through the wire 129 are connected in a rosary shape upward from the bottom lid 203 fixing portion of the wire 129.

Thus, since the wire 129 penetrates the plurality of substantially spherical balls 401, the wire 129 is not subjected to the friction of the solid polycrystalline silicon raw material 155. Therefore, the problem that the wire 129 is directly pressed and fixed by the expanded solid polycrystalline silicon raw material 155 and the bottom lid 203 does not descend is improved. Further, even if the substantially spherical ball 401 is pressed and fixed by the expanded solid polycrystalline silicon raw material 155, the wire 129 slides in the hole 405, so that the bottom lid 203 can be lowered without any problem. is there.
Further, unlike the case where the wire 129 is covered with an integral quartz tube as in Patent Document 3, in the case of the present invention, even if the solid polycrystalline silicon raw material 155 falling in the recharge tube is unevenly distributed, the wire 129 is deformed. By doing so, the stress concentration can be relaxed, so that there is little risk of damage to the substantially spherical ball 401 made of quartz. Since the contact between the metal wire 129 and the solid polycrystalline silicon raw material 155 can be prevented by the presence of the substantially spherical ball 401, the problem of metal contamination can be improved. Further, from the viewpoint of avoiding the contact between the metal wire 129 and the solid polycrystalline silicon raw material 155 as much as possible, as shown in FIG. It is desirable to arrange the balls 401.

Here, the protective member attached to the wire needs to relieve stress concentration due to deformation of the wire at the time of charging. For this purpose, a structure in which a short protective member is connected to a wire is desirable. If the number of protective members is as short as possible, the degree of freedom of the wire increases and the movement becomes easier, and stress concentration is reduced. However, if the protective member has corners, there is a possibility of causing chipping or breakage due to contact between adjacent protective members. Therefore, it is desirable that there are no corners. Therefore, the protective member is preferably (1) having a certain thickness (for maintaining strength), (2) as short as possible, and (3) having no corners.
From the above viewpoint, the protective member is preferably a substantially spherical ball, but may be an elliptical ball as long as sufficient characteristics are obtained.
Here, the quartz forming the substantially spherical ball 401 as the protective member may be opaque quartz or transparent quartz. However, from the viewpoint of suppressing the occurrence of defects such as dislocations due to contamination of single crystals to be produced due to metal impurities contained in quartz, the substantially spherical ball 401 is a high-purity quartz having a metal impurity content of 200 ppm or less. It is desirable that it is made of glass.

Further, in the present embodiment, when the inner diameter of the recharge pipe 201 constituting the cylindrical raw material container 200 is 2R (cm), the weight W (g) of the bottom cover 203 is such that W ≧ 3πR ² . It is desirable to satisfy. This is because, as will be described later in the embodiment, when this relationship is satisfied, the bottom lid 203 is pressed down and fixed directly by the expanded solid polycrystalline silicon raw material 155 due to the weight of the bottom lid 203, and the bottom lid 203 does not descend. This is because the problem is further improved. By satisfying this relationship, the bottom lid 203 tilts and does not return to the lower end of the recharge pipe 201, which is an effective measure against the problem that the raw material container 200 cannot be pulled up.

(Recharge method)
Next, a recharging method using the silicon single crystal manufacturing apparatus configured as described above will be described with reference to FIGS. 1 and 3 to 8.

First, the silicon single crystal manufacturing apparatus 100 opens the gate valve 135 and closes the lid (not shown) provided on the upper side surface of the sub chamber 127.
Next, after the inside of the chamber 111 and the sub-chamber 127 is replaced with an inert gas, a low pressure is maintained in a state where an inert gas such as Ar is supplied. Thereafter, by heating the heaters 107 and 109, a solid polycrystalline silicon raw material (not shown) previously charged in the quartz crucible 101 is melted to obtain a silicon melt 105.
Next, as shown in FIG. 3, the gate valve 135 is closed to shut off the chamber 111 and the sub-chamber 127. Thereby, the sub chamber 127 is returned to normal pressure in a state where the inside of the chamber 111 is maintained in an inert atmosphere and oxidation of the silicon melt 105 is prevented. Thereafter, the lid (not shown) of the sub chamber 127 is opened, and the seed crystal 131 is suspended from the lower end of the wire 129. Then, after suspending the seed crystal 131 from the lower end of the wire 129, the lid (not shown) of the sub chamber 127 is closed, and the sub chamber 127 is sealed.

Thereafter, the subchamber 127 is depressurized and the subchamber 127 is filled with an inert atmosphere such as Ar. Next, the gate valve 135 is opened, and the chamber 111 and the sub-chamber 127 are communicated. In this state, since the seed crystal 131 is located immediately above the silicon melt 105, it is preheated by the radiant heat of the silicon melt 105.
Next, the pulling motor 141 is driven, the seed crystal 131 suspended from the lower end of the wire 129 is lowered, and at least a part of the seed crystal 131 is immersed in the silicon melt 105. When the seed crystal 131 is immersed in the silicon melt 105, the silicon single crystal 123 gradually grows below the seed crystal 131 as shown in FIG. And as the silicon single crystal 123 grows, the silicon single crystal ingot 150 having a desired diameter and length can be pulled by pulling the seed crystal 131 at a predetermined speed.
Thereafter, the grown silicon single crystal ingot 150 is raised to the sub-chamber 127 as shown in FIG. Then, the gate valve 135 is closed, and the chamber 111 and the sub-chamber 127 are shut off. Thereby, the inside of the chamber 111 is maintained in an inert atmosphere, and the sub-chamber 127 is returned to normal pressure in a state in which the silicon melt 105 is prevented from being oxidized. Thereafter, the lid of the sub chamber 127 is opened, and the silicon single crystal ingot 150 is taken out. In this way, the manufacturing process of the first silicon single crystal ingot 150 is completed.

Next, after filling the raw material container 200 with the solid polycrystalline silicon raw material 155 as the raw material to be recharged outside the single crystal manufacturing apparatus, the lid of the subchamber 127 is opened, and the raw material container 200 is connected to the wire as shown in FIG. Suspend at 129.
Next, the cover of the sub chamber 127 is closed, and the sub chamber 127 is sealed. Thereafter, the subchamber 127 is depressurized, and the subchamber 127 is filled with an inert atmosphere.
Next, the gate valve 135 is opened to allow the chamber 111 and the subchamber 127 to communicate with each other. In this state, the pulling motor 141 is driven to lower the raw material container 200 together with the wire 129.
As the raw material container 200 descends, the stopper 205 comes into contact with the flange 128 as shown in FIG. When the wire 129 is further lowered, the recharge pipe 201 is prevented from descending by the flange 128, and only the bottom lid 203 is further lowered as shown in FIG. Then, a gap 210 is formed between the recharge pipe 201 and the bottom cover 203, and the solid polycrystalline silicon raw material 155 falls on the radiation shield cover 301 by its own weight, and the surface of the radiation shield 301 is inclined. Slip and fall into the quartz crucible 101.

  In the present embodiment, since the wire 129 passes through a plurality of substantially spherical balls 401 connected in a bead shape formed of quartz, the wire 129 is fixed by the expanded solid polycrystalline silicon raw material 155. Therefore, the bottom lid 203 can be smoothly lowered.

  Here, the dropping of the solid polycrystalline silicon raw material 155 into the quartz crucible 101 reduces the temperature in the chamber by controlling the heaters 107 and 109, and the surface of the residual silicon melt 105 in the quartz crucible is solidified. It is desirable to be performed at. This is because, by solidifying the surface, it is possible to avoid the problem that the splash due to the splash of the silicon melt 105 adheres to the components in the chamber and shortens the component life.

After all the solid polycrystalline silicon raw material 155 loaded in the recharge tube 127 is put into the quartz crucible 101, the wire 129 is raised. Then, the wire 127 and the bottom lid 203 are raised. Then, by further raising the wire 129, the recharge pipe 201 held by the bottom lid 203 rises integrally with the bottom lid 203.
Note that, after all the solid polycrystalline silicon raw material 155 loaded in the recharge tube 127 is charged into the quartz crucible 101, the temperature in the chamber 111 that has been lowered is set to solidify the surface of the silicon melt 105. Then, the heater is raised by controlling the heaters 107 and 109, and the solid polycrystalline silicon raw material 155 charged into the quartz crucible 101 is melted.
Then, as shown in FIG. 8, after the raw material container 200 is completely raised to the sub-chamber 127, the gate valve 135 is closed and the chamber 111 and the sub-chamber 127 are shut off. As a result, the inside of the chamber 111 is maintained in an inert atmosphere and the lid of the sub-chamber 127 is opened while the silicon melt 105 is prevented from being oxidized, and the inside of the sub-chamber 127 is returned to normal pressure. Thereafter, the raw material container 200 is taken out of the single crystal manufacturing apparatus 100 to complete the recharge process.

  By repeating the manufacturing process and the recharging process of the silicon single crystal ingot 150 described above, the second and subsequent silicon single crystal ingots can be continuously manufactured without replacing the quartz crucible 101.

  Here, solid polycrystalline silicon is used as the solid raw material. However, it is not limited to polycrystalline, and solid single crystal silicon or both may be used. Similarly, when a raw material other than silicon is used, polycrystal, single crystal, or both can be selected as a solid raw material.

  In the above-described embodiment, a silicon single crystal is described as an example as a single crystal. However, the application of the present invention is not necessarily limited to a silicon single crystal, and the Czochralski (CZ) method is used. For example, it can be applied to single crystals such as GaAs single crystals and InP single crystals.

The embodiments of the present invention have been described above with reference to specific examples. In the description of the embodiment, description of the single crystal manufacturing apparatus, the recharging apparatus, the recharging method, etc., which is not directly necessary for the description of the present invention is omitted, but the required single crystal manufacturing apparatus, the recharging are omitted. Elements related to the apparatus, the recharging method, etc. can be appropriately selected and used.
In addition, any solid material recharging apparatus that includes the elements of the present invention and whose design can be changed as appropriate by those skilled in the art is included in the scope of the present invention.

  Hereinafter, examples of the present invention will be described with reference to the drawings, but the present invention is not limited thereto.

Example 1
In this example, a silicon single crystal manufacturing apparatus and a recharging apparatus having the configuration shown in FIG. 1 were used.
A quartz crucible 101 having an inner diameter of 800 mm (32 inches) was used. And 40 kg of solid polycrystalline silicon raw material 155 was recharged with respect to the residual silicon melt 150 kg to 300 kg. The recharge tube 201 was a straight tube having an inner diameter of 270 mm. The wire 129 made of tungsten used in the recharge tube 201 is made of transparent quartz and has a structure in which the substantially spherical balls 401 are connected in a bead shape. The weight of the bottom lid was 2.2 kg.
Under this condition, the recharge tube was lowered for 16 minutes, which is twice the conventional time. As a result of performing the recharge test 10 times, the trouble that the bottom cover 203 hung on the wire 129 did not move down never occurred, and no crack or breakage of the substantially spherical ball 401 was observed.

(Comparative Example 1)
The recharge test was performed 10 times under the same conditions as in Example 1 except that the wire 129 did not have the substantially spherical ball 401. As a result, the trouble that the bottom lid 203 suspended from the wire 129 did not descend occurred four times.

  From the results of Example 1 and Comparative Example 1, it was found that the trouble that the bottom cover 203 does not descend can be effectively avoided by adopting a structure in which the wire 129 penetrates the substantially spherical ball 401.

(Example 2)
In this example, a silicon single crystal manufacturing apparatus and a recharging apparatus having the configuration shown in FIG. 1 were used.
A quartz crucible 101 having an inner diameter of 600 mm (24 inches) was used. And 30 kg of solid polycrystalline silicon raw material 155 was recharged with respect to 80 kg-120 kg of the remaining silicon melt. The recharge tube 201 is a straight tube having an inner diameter of 200 mm. The wire 129 made of tungsten used for the recharge tube 201 has a structure in which a substantially spherical ball 401 made of transparent quartz is penetrated, and the substantially spherical balls 401 are connected in a bead shape. The weight of the bottom cover 203 was 1.0 kg.
Under this condition, the recharge tube was lowered for 12 minutes, twice as much as the conventional method. As a result of performing the recharge test eight times, the trouble that the bottom cover 203 suspended from the wire 129 did not descend never occurred, and the crack or breakage of the substantially spherical ball 401 was not observed.

(Experimental example 3)
The recharge test was performed 10 times under the same conditions as in Example 1 except that the wire 129 did not have the substantially spherical ball 401 and the bottom cover weight was 1.2 kg. As a result, the trouble that the bottom cover 203 suspended from the wire 129 did not descend occurred four times. On the other hand, the bottom cover weight was set to 2.2 kg, and 10 recharge tests were performed under the same conditions.
(Experimental example 4)
A recharge test was performed 10 times under the same conditions as in Example 2 except that the wire 129 did not have the substantially spherical ball 401 and the bottom cover weight was 0.6 kg. As a result, the trouble that the bottom cover 203 suspended from the wire 129 did not descend occurred four times. On the other hand, the bottom cover weight was set to 1.0 kg, and 10 recharge tests were performed under the same conditions.
From these results, when the relationship satisfying the weight of the bottom cover in which the trouble is halved is derived, when the inner diameter of the recharge tube is 2R (cm), the weight W (g) of the bottom cover is a relationship of W ≧ 3πR ² . was gotten.

From the results of Examples 1, 2, 3 and 4, when the wire 129 penetrates the substantially spherical ball 401 and the inner diameter of the recharge tube is 2R (cm), the weight W ( It has been found that g) can more effectively avoid the trouble that the bottom cover 203 does not descend by satisfying the relationship of W ≧ 3πR ² .

It is a typical longitudinal section of a silicon single crystal manufacturing device of an embodiment and an example. It is a figure which shows the substantially spherical ball of embodiment. It is a typical longitudinal section of a silicon single crystal manufacturing device of an embodiment and an example. It is a typical longitudinal section of a silicon single crystal manufacturing device of an embodiment and an example. It is a typical longitudinal section of a silicon single crystal manufacturing device of an embodiment and an example. It is a typical longitudinal section of a silicon single crystal manufacturing device of an embodiment and an example. It is a typical longitudinal section of a silicon single crystal manufacturing device of an embodiment and an example. It is a typical longitudinal section of a silicon single crystal manufacturing device of an embodiment and an example. It is a typical longitudinal cross-sectional view of the silicon single crystal manufacturing apparatus of a prior art. It is a typical longitudinal cross-sectional view of the silicon single crystal manufacturing apparatus of a prior art.

Explanation of symbols

101 Quartz crucible 105 Silicon melt 106 Solidified surface 111 Chamber 125 Radiation shield 127 Subchamber 129 Wire 135 Gate valve
141 Pulling motor 155 Solid polycrystalline silicon raw material 200 Raw material container 201 Recharge pipe 203 Bottom lid 210 Gap 401 Substantially spherical ball

Claims (4)

A cylindrical raw material container filled with a solid raw material to be supplied to the crucible storing the crystal melt, and a wire for suspending the cylindrical raw material container whose one end is fixed to the center of the bottom lid of the cylindrical raw material container; A solid-state raw material recharging device comprising:
A solid material recharging apparatus, wherein the wire penetrates a plurality of elliptical or substantially spherical balls made of quartz.   2. The solid material recharging device according to claim 1, wherein the oval or substantially spherical ball is made of high-purity quartz glass having a metal impurity content of 200 ppm or less.   The recharge apparatus for a solid material according to claim 1 or 2, wherein the recharge pipe constituting the cylindrical material container has a straight shape with a constant inner diameter from the upper end to the lower end. The weight W (g) of the bottom cover satisfies the relationship of W ≧ 3πR ² when the inner diameter of the recharge pipe constituting the cylindrical raw material container is 2R (cm). 3. The solid material recharging device according to 3.

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