JP2007254162A - Single crystal manufacturing device and recharge method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a single crystal manufacturing device and a recharge method in which the total amount of a solid polycrystalline source material supplied in one recharge is increased and high productivity can be achieved in the manufacture of a single crystal such as silicon by Czochralski method. <P>SOLUTION: The single crystal manufacturing device 100 is equipped with a radiation shield 125 disposed inside a crucible 101 and with a radiation shield cover 301 covering the inner side and an upper side of the radiation shield 125, wherein a solid polycrystalline source material 155 filling a recharge tube 201 drops by gravity through a gap between the lower end outer rim of the recharge tube 201 and a bottom cap 203 disposed at the lower end of the recharge tube 201 onto the radiation shield cover 301, slides on a slope surface of the radiation shield 301 and drops with reduced fall energy into the quartz crucible 101 reserving a crystal melt 105. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a Czochralski method (CZ method) single crystal manufacturing apparatus and recharge method having a solid material recharge mechanism, and in particular, a Czochralski method having a recharge mechanism for supplying a solid material by a recharge tube recharge method. (CZ method) The present invention relates to a single crystal manufacturing apparatus and a recharging method.

A so-called Czochralski method (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 multi-drawing operations also produce single crystals from crucibles that can only be used once, improve single crystal productivity, and effectively use 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. 8 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. 8, the silicon single crystal manufacturing apparatus 100 is provided with a recharging device. And this recharge apparatus winds up the cylindrical raw material container 200 which uses the recharge pipe | tube 201 with which the solid silicon polycrystal raw material 155 is filled as a component, the wire 129 which suspends this cylindrical raw material container 200, and the wire 129 A pulling motor 141 is used. 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.
Then, the solid silicon polycrystalline raw material 155 filled in the recharge pipe 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 sub chamber 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 surface of the silicon melt 105.

In recent years, the diameter of single crystals has been increased, and in particular for silicon single crystals, production of Φ300 mm (12 inches) crystals is becoming mainstream. And in order to implement | achieve high productivity in such a large diameter silicon single crystal, it is necessary to increase the weight of the solid-state polycrystalline raw material 155 with which the recharge pipe | tube 201 is filled, and to make the recharge frequency | count as small as possible. For this reason, the diameter of the recharge pipe 201 is also increased.
However, in order to obtain a high-quality crystal by controlling the temperature of the pulled single crystal, a radiation shield 125 is installed in the single crystal manufacturing apparatus 100 so as to surround the pulled single crystal. Therefore, normally, the maximum diameter of the recharge pipe 201 is sufficiently smaller than the inner diameter of the radiation shield 125 as shown in FIGS. Thus, the reason for limiting the maximum diameter of the recharge pipe 201 is as follows.

The supply of the solid polycrystalline silicon raw material 155 needs to be performed at a position where the tip of the recharge tube 201 is lower than the lower end of the radiation shield 125. This is to prevent the solid polycrystalline silicon raw material 155 from directly colliding with the radiation shield 125 when the solid polycrystalline silicon raw material 155 is supplied. Thus, in order to avoid collision, the radiation shield 125 is made of a highly heat-insulating material, that is, a metal such as molybdenum, tungsten, or tantalum, in order to block the radiation heat of the quartz crucible 101 or the silicon melt 105. In addition, carbon, carbon whose surface is coated with silicon carbide, or the like is used. This is because when these metal elements and carbon are dropped into the silicon melt 105 as an impurity by the impact of the solid silicon polycrystalline raw material 155, dislocation occurs in the silicon single crystal. .
If the inner diameter of the recharge tube 201 is made larger than the inner diameter of the radiation shield 125, it becomes impossible to insert the recharge tube 201 to the lower end of the radiation shield as shown in FIG. The position of the lower end of the recharge tube 201 from the silicon melt surface or the solidified surface 106 becomes higher. Then, the falling energy of the supplied solid polycrystalline silicon raw material 155 increases, and there is a possibility that problems such as silicon melt jumping and quartz crucible damage due to the solid polycrystalline silicon raw material 155 bounced off the solid surface may occur.
Japanese National Patent Publication No. 2002-068732

For the above reason, the inner diameter of the recharge pipe 201 has a restriction due to the inner diameter of the radiation shield. Therefore, in order to further increase the weight of the solid raw material filled in the recharge tube, an approach of increasing the length of the recharge tube has been taken.
However, increasing the length of the recharge tube increases the drop energy of the solid polycrystalline silicon raw material that fills the top of the recharge tube. Therefore, the problem that breakage such as cracks and chippings occurs in the lower part of the recharge pipe has become apparent.

  The present invention has been made in consideration of the above circumstances, and its object is to increase the total amount of solid raw materials that can be supplied by a single recharge, and to achieve high productivity. It is to provide an apparatus and a recharging method.

An apparatus for producing a single crystal of one embodiment of the present invention includes:
Single crystal production having a recharge mechanism for supplying a solid raw material filled in a recharge tube to a crucible for storing a crystal melt from a gap between the outer edge of the lower end of the recharge tube and a bottom lid disposed at the lower end of the recharge tube A device,
A radiation shield disposed on the inner surface side of the crucible;
A single crystal manufacturing apparatus comprising a radiation shield cover covering the inner surface side and the upper surface side of the radiation shield.

  Here, it is desirable that an inner diameter of the lower end of the recharge pipe is larger than a minimum inner diameter of the radiation shield.

  Here, it is desirable that the radiation shield cover is made of transparent quartz.

The recharge method of one embodiment of the present invention includes:
A recharging method for supplying a solid raw material filled in a recharge pipe to a crucible for storing a crystal melt,
A recharging method comprising: supplying the solid raw material to the crucible by dropping the solid raw material from the recharge pipe onto a radiation shield cover covering a radiation shield inner surface side and an upper surface side. .

  According to the present invention, there is provided a single crystal manufacturing apparatus and a recharge method capable of increasing the total amount of solid raw materials that can be supplied by one recharge by increasing the inner diameter of the recharge pipe and realizing high productivity. It becomes possible to do.

  Embodiments of a single crystal manufacturing apparatus 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]
(Single crystal manufacturing equipment)
First, the configuration of the silicon single crystal manufacturing apparatus used in the 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. The radiation shield 125 plays a role of adjusting radiant heat, so a highly heat-insulating material, for example, a metal such as molybdenum, tungsten, or tantalum, carbon, a surface of carbon coated with silicon carbide, and the inside thereof The one provided with a molded heat insulating material is used.

  The single crystal manufacturing apparatus of the present embodiment is characterized in that a radiation shield cover 301 is provided so as to cover the inner surface side and the upper surface side of the radiation shield 125. The radiation shield cover 301 prevents the solid polycrystalline silicon raw material 155 supplied from the raw material container 200 from colliding with the radiation shield 125.

The radiation shield cover 301 is preferably made of a material that does not relatively affect the quality of the silicon single crystal even if it enters the silicon melt 105, for example, silicon or quartz.
And since it has high heat permeability and does not change the thermal environment in the chamber 111, it is desirable that it be formed of transparent quartz from the viewpoint of being easily attached to an existing single crystal manufacturing apparatus.

Furthermore, as shown in FIG. 1, it is desirable that the maximum inclination angle of the radiation shield cover 301 with respect to the horizontal plane is smaller than the maximum inclination angle of the radiation shield with respect to the horizontal plane. This is because, by providing such a taper, the falling energy of the supplied solid silicon polycrystalline raw material 155 can be reduced, and the problem of quartz crucible damage due to the jumping or impact of the silicon melt 105 can be suppressed. Because it becomes.
The distance from the lower end of the radiation shield cover 301 to the silicon melt 105 is preferably designed to be sufficiently short in order to prevent the quartz crucible from being damaged by jumping or impact, and particularly preferably 400 mm or less.

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 from the silicon melt 105 and a raw material container 200 to be described later is provided above the chamber 111 via 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 147. At the lower end of the wire 129, the seed crystal 131 is suspended as shown in FIG. 2 in the silicon single crystal pulling process, and the raw material container 200 is suspended in the recharging process as shown in FIG. .

  Next, the recharging device will be described. First, in the recharging apparatus that can be used in the present invention, the raw material container 200 is suspended by a wire 129 as shown in FIG. The raw material container 200 includes a recharge pipe 201, a bottom cover 203, and a ring 204 through which a wire 129 passes 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. In addition, a stopper 205 for latching the recharge tube 201 with a flange 128 provided in the sub chamber 127 is provided on the outer periphery of the recharge tube 201.

In the present embodiment, the inner diameter of the lower end of the recharge pipe 201 is substantially the same as or more than the minimum inner diameter of the radiation shield 125. Thereby, it becomes possible to increase the amount of the solid silicon polycrystalline raw material filled in the raw material container 200 as compared with the conventional case. In particular, the inner diameter of the lower end of the recharge pipe 201 is desirably larger than the minimum inner diameter of the radiation shield 125. This is because it is possible to increase the solid silicon polycrystalline raw material 155 that can be refilled in the recharge pipe 201 significantly compared to the conventional case.
The inner diameter of the lower end of the recharge pipe 201 is preferably smaller than the outer diameter of the inclined portion of the radiation shield cover 301. This is because there is a high possibility that the falling solid polycrystalline silicon raw material 151 will not be supplied into the quartz crucible.
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.

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

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. 2, the gate valve 135 is closed, and the chamber 111 and the sub-chamber 127 are shut off. 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 seed crystal 131 is immersed in silicon melt 105, silicon single crystal 123 gradually grows below 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 lowering by the flange 128, and only the bottom lid 203 is further lowered as shown in FIG. As a result, a gap 210 is formed between the outer edge of the lower end of the recharge tube 201 and the bottom lid 203, and the solid polycrystalline silicon raw material 155 falls on the radiation shield cover 301 by its own weight from the gap 210, and the radiation shield 301. It slides down the slope of the surface and falls into the quartz crucible 101.

  As described above, the solid polycrystalline silicon raw material 155 falls on the radiation shield cover 301 and slides on the surface of the radiation shield 301, so that the falling energy of the solid polycrystalline silicon raw material 155 is reduced as described above. . Therefore, even if the position of the lower end of the recharge tube 201 at the time of supplying the solid polycrystalline silicon 155 from the silicon melt surface or the solidified surface 106 is higher than that in the conventional technique, the silicon melt jumps, the quartz crucible breakage, etc. The problem can be suppressed.

  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. 7, 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, in the embodiment described above, 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 is pulled up using the Czochralski (CZ) method. For example, a single crystal such as a GaAs single crystal or an InP single crystal can be applied.

  Here, as a solid material filled in the recharge tube, a silicon polycrystalline material has been described as an example, but the solid material is not necessarily limited to a polycrystalline material, and may be a single crystal or both. . Even when a single crystal other than silicon is pulled, it is the same that a polycrystal, a single crystal, or both can be used as a solid raw material.

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, all single crystal manufacturing apparatuses and recharging methods that include elements of the present invention and that can be appropriately modified by those skilled in the art are 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.

In this example, a silicon single crystal manufacturing apparatus and a recharging apparatus having the configuration shown in FIG. 1 were used.
First, a quartz crucible 101 having an inner diameter of 600 mm (24 inches) was used. The quartz crucible 101 was provided with a radiation shield 125 made of 205 mm (8 inch) single crystal carbon and having a minimum inner diameter of 240 mm. A radiation shield cover 301 made of transparent quartz having a thickness of 5.0 mm is provided to cover the inner surface side and upper surface side of the radiation shield 125.

And the recharge pipe | tube 201 of the raw material container 200 used the size of internal diameter (phi) 270mm and length 1400mm. This recharge pipe 201 is filled with a solid polycrystalline silicon raw material 1.5 times, that is, 60 kg in weight, compared to a recharge pipe having an inner diameter of φ200 mm and a length of 1400 mm, because of the limitations that come from the inner diameter of the radiation shield 125 conventionally. It became possible.
The distance from the lower end of the radiation shield cover 301 to the silicon melt 105 was 300 mm.

The recharging operation was performed with the above configuration. Problems such as adhesion of silicon droplets to parts in the chamber, damage due to the impact of the quartz crucible, and dislocation of the pulled silicon single crystal after recharging did not become apparent.
In the case of a conventional recharge tube having an inner diameter of 200 mm, two recharge operations are required to recharge 60 kg of solid silicon polycrystalline material. However, the use of the recharge tube having an inner diameter of 270 mm in this embodiment can reduce the recharge work to one time, and the work time can be reduced by 90 minutes.

  As described above, in the examples, it has been found that high productivity can be realized in the single crystal manufacturing apparatus and the recharging method of the present invention having a recharge pipe having a larger diameter than before.

It is a typical longitudinal cross-sectional view of the silicon single crystal manufacturing apparatus of Embodiment 1 and an Example. It is a typical longitudinal cross-sectional view of the silicon single crystal manufacturing apparatus of Embodiment 1 and an Example. It is a typical longitudinal cross-sectional view of the silicon single crystal manufacturing apparatus of Embodiment 1 and an Example. It is a typical longitudinal cross-sectional view of the silicon single crystal manufacturing apparatus of Embodiment 1 and an Example. It is a typical longitudinal cross-sectional view of the silicon single crystal manufacturing apparatus of Embodiment 1 and an Example. It is a typical longitudinal cross-sectional view of the silicon single crystal manufacturing apparatus of Embodiment 1 and an Example. It is a typical longitudinal cross-sectional view of the silicon single crystal manufacturing apparatus of Embodiment 1 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 Pull-up motor 155 Solid polycrystalline silicon raw material 200 Raw material container 201 Recharge pipe 203 Bottom lid 210 Gap 301 Radiation shield cover

Claims (4)

Single crystal production having a recharge mechanism for supplying a solid raw material filled in a recharge tube to a crucible for storing a crystal melt from a gap between the outer edge of the lower end of the recharge tube and a bottom lid disposed at the lower end of the recharge tube A device,
A radiation shield disposed on the inner surface side of the crucible;
An apparatus for producing a single crystal, comprising a radiation shield cover covering the radiation shield inner surface side and upper surface side.   The single crystal manufacturing apparatus according to claim 1, wherein an inner diameter of the lower end of the recharge pipe is larger than a minimum inner diameter of the radiation shield.   The single crystal manufacturing apparatus according to claim 1, wherein the radiation shield cover is made of transparent quartz. A recharging method for supplying a solid raw material filled in a recharge pipe to a crucible for storing a crystal melt,
A recharging method comprising: supplying the solid raw material to the crucible by dropping the solid raw material from the recharge pipe onto a radiation shield cover covering a radiation shield inner surface side and an upper surface side.

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