JP2007246357A - Recharging tube for solid raw material, and recharging method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recharging tube improving the productivity of a single crystal by preventing breakage of the tube in production of the single crystal by the Czochralski method, and to provide a recharging method using the same. <P>SOLUTION: The recharge of a solid raw material is performed by using the recharging tube for filling a crystal melt-storing crucible with the solid raw material, wherein the lower half 301 of the tube is higher in fracture toughness than the upper half 303. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a solid material recharge tube and a recharge method using the same in an apparatus for producing a single crystal 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 raw material lump is accommodated in a crucible installed in a growth furnace, and a heater is heated at 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. A single pulling operation that pulls up a single crystal in one operation is widely used, but a multi-pulling operation that pulls up a plurality of single crystals also tends to increase gradually due to the spread of recharge technology.
This type of multi-drawing operation produces multiple single crystals from a crucible that can only be used once, improves single crystal productivity, and effectively uses expensive crucibles to reduce single crystal production costs. The purpose is to plan.
As one of the recharge methods used in the above multi-drawing operation, a recharge pipe recharge method is known (for example, see Patent Document 1 and Patent Document 2). In this recharge tube recharge method, for example, after pulling up a silicon single crystal, a cylindrical recharge tube made of, for example, quartz is filled and held with a solid polycrystalline silicon raw material of the pulled weight. Then, from the lower end of the recharge pipe close to the melt surface, the polycrystalline silicon raw material is dropped onto a solidified surface obtained by solidifying the melt surface in advance, and the raw material is recharged.

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. In order to achieve high yield and high productivity in such a large-diameter silicon single crystal, it is necessary to increase the weight of the solid raw material filled in the recharge tube and reduce the number of recharges as much as possible. For this reason, the diameter of the recharge pipe is also increased.
However, in order to obtain a high-quality crystal by controlling the temperature of the pulling single crystal, a radiation shield and a purge pipe are installed in the pulling device so as to surround the pulling single crystal. Therefore, it is usually difficult to make the maximum diameter of the recharge tube larger than the pulled crystal diameter. Therefore, in order to further increase the weight of the solid raw material filled in the recharge pipe, the length of the recharge pipe must be increased.
JP 57-95891 A Japanese National Patent Publication No. 2002-068732

Due to the increase in the length of the recharge tube accompanying the increase in the diameter of the single crystal as described above, the problem that damage such as cracks and chipping occurs in the lower portion of the recharge tube has become apparent.
This is because the solid material to be recharged is filled to a higher position with respect to the lower end of the recharge tube as the recharge tube becomes longer. For this reason, when the solid raw material is thrown into the crucible, the falling energy of the raw material increases and drops with momentum, so that it is easy to cause breakage at the collision location especially when colliding at the lower part of the recharge pipe. is there.
This breakage may be caused by a single impact force of the solid raw material falling, or may be caused by accumulation of strain due to repeated collisions in a recharge tube that is repeatedly used.
If the recharge tube is damaged during the charging of the recharge material and splashes into the chamber or melt, it is extremely difficult to recover the scattered recharge tube fragments. Therefore, the operation may have to be stopped for a long time, which greatly impedes the productivity of the single crystal.
Also, even if the recharge tube fragments do not scatter, the damaged recharge tube must be replaced. Therefore, the cost of the expensive recharge tube rebounds on the single crystal production cost, resulting in a problem that the single crystal production cost increases.
As described above, while the problem of breakage due to the lengthening of the recharge pipe becomes obvious, one demand is to reduce the weight of the recharge pipe. This is because if the recharge device becomes heavier due to the length of the recharge tube, it becomes difficult to transport the recharge device outside the single crystal manufacturing device or to handle the recharge device when filling the solid raw material. Take that to get worse. Further, when the weight of the recharging device becomes heavy, it is necessary to increase the pulling motor performance due to an increase in the load on the pulling power of the wire pulling device. For this reason, the cost of the single crystal manufacturing apparatus and thus the cost of the single crystal are increased.

  The present invention has been made in view of the above circumstances, and the object of the present invention is to prevent breakage of the recharge tube, in particular by increasing the fracture toughness at the lower part of the recharge tube, thereby increasing the productivity of the single crystal. It is an object of the present invention to provide a recharge tube that can be improved and a recharge method using the same.

The solid-state raw material recharge pipe of one embodiment of the present invention is
A recharge pipe for a solid material provided in a single crystal manufacturing apparatus having a crucible for storing a crystal melt, and for filling the crucible with a solid material,
The lower half of the recharge pipe has a fracture toughness greater than that of the upper half.

The solid-state raw material recharge pipe of one embodiment of the present invention is
A recharge pipe for a solid material provided in a single crystal manufacturing apparatus having a crucible for storing a crystal melt, and for filling the crucible with a solid material,
A solid material recharge tube characterized in that the lower half of the recharge tube is thicker than the upper half.

The solid-state raw material recharge pipe of one embodiment of the present invention is
A recharge pipe for a solid material provided in a single crystal manufacturing apparatus having a crucible for storing a crystal melt, and for filling the crucible with a solid material,
A solid material recharge tube, wherein a reinforcing material is provided in a lower half of the recharge tube.

The solid-state raw material recharge pipe of one embodiment of the present invention is
A recharge pipe for a solid material provided in a single crystal manufacturing apparatus having a crucible for storing a crystal melt, and for filling the crucible with a solid material,
It is a solid material recharge tube characterized in that a spiral projection is provided on the inner wall of the lower half of the recharge tube.

The solid-state raw material recharge pipe of one embodiment of the present invention is
A recharge pipe for a solid material provided in a single crystal manufacturing apparatus having a crucible for storing a crystal melt, and for filling the crucible with a solid material,
A solid material recharge tube characterized in that the lower half of the recharge tube has a greater fracture toughness than the upper half,
A solid material recharge tube comprising a plurality of openings in the upper half of the recharge tube.

The recharge method using the solid-state material recharge tube of one embodiment of the present invention is as follows.
A recharge method using a solid material recharge tube provided in a single crystal manufacturing apparatus having a crucible for storing a crystal melt and filling the crucible with a solid material,
A recharge method using a solid material recharge tube, wherein the lower half of the recharge tube has a fracture toughness greater than that of the upper half.

In this specification, the fracture toughness of the lower half of the recharge tube is larger than that of the upper half. The average value of the fracture toughness of the lower half when the recharge tube is divided into two equal parts in the length direction is the fracture of the upper half. It means larger than the average value of toughness.
Further, in this specification, the lower half of the recharge tube is thicker than the upper half because the average value of the thickness of the lower half when the recharge tube is divided into two equal parts in the length direction is the upper half. It means that it is larger than the average thickness.
Further, in this specification, that the reinforcing material is provided in the lower half of the recharge pipe means that the reinforcing material is provided in at least a part of the lower half when the recharge pipe is divided into two equal parts in the length direction. Means that
In the present specification, the provision of a spiral convex portion on the inner wall of the lower half of the recharge tube means that the inner wall of at least a part of the lower half when the recharge tube is divided into two equal parts in the length direction. It means that a spiral convex part is provided.
Further, in this specification, providing a plurality of openings in the upper half of the recharge tube means providing a plurality of openings in at least a portion of the upper half when the recharge tube is equally divided into two in the length direction. Means.

  According to the present invention, by increasing the fracture toughness of the lower half of the recharge tube, the recharge tube can be prevented from being damaged, and thus the productivity of single crystals can be improved, and a recharge method using the same It becomes possible to provide.

Embodiments of a solid material recharge tube and a recharge method using the same 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.
First, before describing embodiments of the present invention in detail, a single crystal manufacturing apparatus and a recharging method that can be used in the present invention will be briefly described with reference to the drawings.

(Single crystal manufacturing equipment)
First, an aspect of the configuration of a silicon single crystal manufacturing apparatus that can be used in the present invention will be briefly described.
FIG. 8 is a schematic longitudinal sectional view of a silicon single crystal manufacturing apparatus that can be used in the present invention.
The silicon single crystal manufacturing apparatus shown in FIG. 8 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 housed in the chamber 111, and a pulling mechanism (not shown) for pulling up the grown silicon single crystal (not shown) is provided on the upper portion of the chamber 111.
A pulling wire 129 is unwound from a pulling mechanism attached to the upper part of the chamber 1, and a seed holder (not shown) for mounting a seed crystal 131 is connected to the tip of the pulling wire 129.

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 123 so that the heat from the silicon melt 105 and the crucibles 101 and 103 is not pulled up and hinders the cooling of the silicon single crystal 123. ing. 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 the role of adjusting the radiant heat. For example, metal such as molybdenum, tungsten, and tantalum, carbon, the surface of carbon is covered with silicon carbide, and a molded heat insulating material is installed inside these. Used.

  The fact that such a radiation shield 125 is provided inside the crucibles 101 and 103 is a factor that limits the maximum diameter of a recharge tube (not shown) as described above.

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 the silicon single crystal 123 pulled from the silicon melt 105 is provided at the upper portion of the chamber 111 via a gate valve (not shown). A flange 128 is provided on the inner peripheral surface of the sub-chamber 127 for hooking a recharge pipe to be described later. Although not shown, the upper end of the sub chamber is sealed with a top plate, and a sub chamber lid is provided on the upper side surface of the sub chamber so that the pulled up silicon single crystal 123 and a recharging device to be described later can be taken out. Yes.

  A wire pulling device (not shown) is provided above the sub chamber 127. The wire pulling device holds the wire 129 in a vertically movable manner, 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, the seed crystal 131 is suspended as shown in FIG. 8 during the silicon single crystal pulling process, and the recharging device 200 is suspended as shown in FIG. 11 during the recharging process. .

Next, the recharging device will be described. First, as shown in FIG. 11, a recharge device 200 that can be used in the present invention includes a recharge pipe 201, a bottom cover 203, and a ring 204 through which a wire 129 is passed to stabilize the recharge pipe 201 on the central axis of the subchamber 127. It is configured. 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 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.
Here, since the recharge tube 201 is close to the silicon melt 105, it is excellent in heat resistance and preferably does not contaminate the wafer, and is excellent in workability and is preferably quartz from a relatively inexpensive point. Silicon carbide, silicon nitride, aluminum oxide, or the like can be used.

(Recharge method)
Next, one mode of a recharging method using the silicon single crystal manufacturing apparatus and the recharging 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. 8, 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.
After the seed crystal 131 is suspended 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 wire 129 pulling device 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, outside the single crystal manufacturing apparatus, the solid polycrystalline silicon raw material 155 that is a raw material to be recharged is filled into the recharging apparatus 200, then the lid of the subchamber 127 is opened, and the recharging apparatus 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 recharge device 200 is lowered together with the wire 129.
When the recharging device 200 is lowered, 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. Then, a gap 210 is formed between the recharge tube 201 and the bottom cover 203, and the solid polycrystalline silicon raw material 155 falls into the quartz crucible 101 by its own weight from the gap 210.

At this time, if the recharge tube 201 is long, the drop energy of the solid polycrystalline silicon raw material 155 filled in the upper portion of the recharge tube 201 becomes large. Therefore, the possibility that the recharge tube 201 is damaged due to the solid polycrystalline silicon raw material 155 colliding with the inner wall of the lower portion of the recharge tube 201 increases.
The dropping of the solid polycrystalline silicon raw material 155 into the quartz crucible 101 is performed with the surface of the residual silicon melt 105 in the quartz crucible solidified by controlling the heaters 107 and 109 to lower the temperature in the chamber. It is desirable that This is because, by solidifying the surface, it is possible to avoid the problem that the droplets of the silicon melt 105 adhere to the components in the chamber and shorten 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. 14, after the recharge device 200 has completely moved up 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 recharge apparatus 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.

[Embodiment 1]
Next, the recharge tube of the first embodiment will be described. The recharge tube of the present embodiment is characterized in that the lower half of the recharge tube is thicker than the upper half.
FIG. 1 is an explanatory diagram of a recharge tube according to the present embodiment. As shown in FIG. 1, for example, the lower half 301 of the recharge tube made of quartz is thicker than the upper half 303.

  Thus, by making the lower half of the recharge pipe, which is entirely made of the same material, thicker than the upper half, the fracture toughness of the lower half of the recharge pipe can be made larger than the upper half. Therefore, at the time of recharging, it is possible to prevent damage to the lower part of the recharge tube, which collides with a solid material having a particularly high drop energy, and as a result, it is possible to improve the productivity of single crystals.

  In addition, by suppressing the thickness of the upper half of the recharge tube, solid materials with high fall energy do not collide, and therefore high fracture toughness is not required. I can do it. In addition, by reducing the total weight of the recharge device, it becomes easier to transport the recharge device outside the single crystal manufacturing device and to handle the recharge device when filling the solid raw material. It becomes possible to improve. In addition, reducing the total weight of the recharging device also reduces the burden on the pulling power of the wire pulling device, so there is no increase in the performance of the pulling motor and the single crystal manufacturing device cost and thus the single crystal cost. Can also contribute to the reduction of

Such a recharge tube can be easily produced by, for example, welding quartz tubes having different thicknesses. Further, for example, if molds having different thicknesses are produced in the upper half and the lower half and are produced by integral molding by casting, it is possible to obtain a recharge tube having a higher overall strength than welding.
Further, in FIG. 1, the thickness corresponding to ½ of the length of the recharge tube from the lower end is increased, but if the fracture toughness of the lower half is increased, it is not necessarily limited to ½, The thickness of the 1/3 or 1/4 portion may be increased, or the thickness of the 2/3 portion may be increased.
The material of the recharge tube is close to the silicon melt, so that it is excellent in heat resistance and preferably does not contaminate the wafer. Quartz is preferable because it is excellent in workability and relatively inexpensive. Silicon, silicon nitride, aluminum oxide, or the like can be used.

[Modification of Embodiment 1]
FIG. 2 is an explanatory diagram of a recharge tube according to a modification of the first embodiment. As shown in FIG. 2, for example, a lower end opening 305 of a recharge tube made of quartz is built up.

Thus, since one end is an open surface, the fracture toughness of the lower end open part of the recharge pipe can be made larger than the other parts by building up the lower end open part of the recharge pipe that is particularly vulnerable to impact. . Therefore, at the time of recharging, it is possible to prevent breakage of the open portion of the lower end of the recharge pipe where the solid raw material having a high drop energy collides, and as a result, it becomes possible to improve the productivity of the single crystal.
Moreover, for example, when a quartz tube is used, the overlay as shown in FIG. 2 can be easily formed by heating only the lower end of the molded quartz tube and applying a force from below. Therefore, it is possible to reduce the manufacturing cost of the recharge tube. In addition, a similar shape can be formed by welding linear quartz on the circumference of the lower end of the recharge tube. Also in this case, there is an advantage that a recharge pipe having a lower half toughness and high fracture toughness can be easily supplied at a lower cost than in the first embodiment.

[Embodiment 2]
Next, the recharge tube of the second embodiment will be described. The recharging device of the present embodiment is characterized in that a reinforcing material is provided in the lower half of the recharging pipe.
FIG. 3 is an explanatory diagram of the recharge tube of the present embodiment. As shown in FIG. 3, for example, a plurality of reinforcing members 307 made of quartz are provided in the lower half region of the recharge pipe made of quartz.

Thus, by providing the reinforcing material in the lower half of the recharge tube, the fracture toughness of the lower half of the recharge tube can be made larger than that of the upper half. Therefore, at the time of recharging, it is possible to prevent damage to the lower part of the recharge tube, which collides with a solid material having a particularly high drop energy, and as a result, it is possible to improve the productivity of single crystals.
Further, the same effect as in the first embodiment can be obtained by suppressing the total weight of the entire recharging device.
Further, such a recharge tube can be produced simply by welding linear quartz to the quartz tube, and has an advantage that it can be formed more easily and at a lower cost than the first embodiment.

In FIG. 3, the reinforcing material is provided in a portion corresponding to ½ of the length of the recharge pipe from the lower end. However, if the fracture toughness of the lower half is increased, it is not necessarily limited to ½, Further, a reinforcing material may be provided in the 1/3 or 1/4 portion, or a reinforcing material may be provided in the 2/3 portion.
And as for the shape of the reinforcing material, if the fracture toughness of the lower half is increased, the shape of the reinforcing material is not necessarily a straight line extending in the length direction of the recharge tube as shown in FIG. You may form, for example, you may form in a grid | lattice form, or you may form in a spiral form, for example.
The selection of the recharge tube material is the same as that in the first embodiment. As for the reinforcing material, when quartz is used for the recharge tube, it is desirable to use quartz for the reinforcing material because of ease of welding.
However, the material of the recharge tube and the material of the reinforcing material are not necessarily the same. As for the material of the reinforcing material, since it is close to the silicon melt like the material of the recharge tube, it is preferable that it has excellent heat resistance and does not contaminate the wafer. Quartz, silicon carbide, silicon nitride, or oxidation Aluminum or the like can be used.

[Embodiment 3]
Next, the recharge tube of the third embodiment will be described. The recharge tube of the present embodiment is characterized in that a spiral convex portion is provided on the inner wall of the lower half of the recharge tube.
FIG. 4 is an explanatory diagram of the recharge tube of the present embodiment. As shown in FIG. 4, for example, a spiral convex portion 309 made of quartz is provided on the inner wall of the lower half region of the recharge tube made of quartz.

Thus, the provision of the spiral protrusion on the inner wall of the lower half of the recharge tube can make the fracture toughness of the lower half of the recharge tube larger than the upper half. Therefore, at the time of recharging, it is possible to prevent damage to the lower part of the recharge tube, which collides with a solid material having a particularly high drop energy, and as a result, it is possible to improve the productivity of single crystals.
Further, the same effect as in the first embodiment can be obtained by suppressing the total weight of the entire recharging device.
Further, such a recharge tube can be produced simply by welding linear quartz to the inner wall of the quartz tube, and has an advantage that it can be formed more easily and cheaply than the first embodiment. Further, for example, a mold having such a spiral portion can be made and manufactured by casting.
In FIG. 4, the spiral convex portion is provided on the inner wall of the portion corresponding to ½ of the length of the recharge tube from the lower end. However, if the fracture toughness of the lower half is increased, it is not necessarily 1 / For example, a convex portion may be provided at a 1/3 or 1/4 portion, or a convex portion may be provided at a 2/3 portion.

The selection of the recharge tube material is the same as in the first embodiment. As for the spiral convex portions, when quartz is used for the recharge tube, it is desirable to use quartz also for the spiral convex portions for ease of welding.
However, the material of the recharge tube and the material of the spiral convex portion are not necessarily the same. As for the material of the spiral convex portion, it is preferable that the material is close to the silicon melt as well as the material of the recharge tube, so that it has excellent heat resistance and does not contaminate the wafer. Quartz, silicon carbide, silicon nitride Alternatively, aluminum oxide or the like can be used.
Furthermore, by providing the spiral convex portion on the inner wall of the lower half of the recharge pipe as described above, the falling trajectory of the solid raw material has a spiral component along the convex portion. Therefore, compared with the case where there is no spiral convex part, the raw material drop energy is reduced, and there is an effect of further reducing damage to the lower part of the recharge tube.

[Embodiment 4]
Next, the recharge tube of the fourth embodiment will be described. The recharge tube of the present embodiment is characterized in that a plurality of openings are provided in the upper half of the recharge tube, and the lower half of the recharge tube is thicker than the upper half.
FIG. 5 is an explanatory diagram of the recharge tube of the present embodiment. As shown in FIG. 5, for example, a plurality of elliptical openings 315 are provided in the upper half of the recharge tube made of quartz, for example. In addition, the lower half 301 of the recharge tube is thicker than the upper half 303.

Thus, by making the lower half of the recharge pipe, which is entirely made of the same material, thicker than the upper half, the fracture toughness of the lower half of the recharge pipe can be made larger than the upper half. Therefore, when recharging, it is possible to prevent breakage of the lower part of the recharge tube, which collides with a solid raw material with particularly high drop energy, and as a result, it becomes possible to improve the productivity of single crystals. This is the same as in the first to third embodiments.
In addition, by providing an opening in the upper half of the recharge tube that does not collide with a solid raw material having a high fall energy and therefore does not require high fracture toughness, the cost increase due to the use of extra material is further increased. Can be suppressed. Furthermore, by further reducing the total weight of the entire recharging device, it becomes easier to transport the recharging device outside the single crystal manufacturing device and to handle the recharging device when filling the solid raw material. It becomes possible to improve productivity. Furthermore, further reducing the total weight of the entire recharging device also reduces the burden on the pulling power of the wire pulling device, so there is no increase in the performance of the pulling motor, and the single crystal manufacturing device cost and hence the single unit. It can further contribute to the reduction of crystal cost.

Such a recharge tube can be easily formed by, for example, forming an opening by cutting after welding quartz tubes having different thicknesses. In addition, for example, if a mold having different thicknesses in the upper half and the lower half and having an opening in the upper half is made by casting and integrated molding, a recharge tube with higher overall strength than welding is obtained. It becomes possible.
Further, in FIG. 5, an opening is provided in a portion corresponding to ½ of the length of the recharge tube from the upper end, but if the weight of the upper half is reduced, it is not necessarily limited to ½, , 1/3 or 1/4 may be provided with an opening, or 2/3 may be provided with an opening.
In FIG. 5, the thickness of the portion corresponding to ½ of the length of the recharge tube from the lower end is increased, but if the fracture toughness of the lower half is increased, it is not necessarily limited to ½, The thickness of the 1/3 or 1/4 portion may be increased, and the thickness of the 2/3 portion may be increased as in the first embodiment.

The material of the recharge tube is close to the silicon melt, so that it is excellent in heat resistance and preferably does not contaminate the wafer. Quartz is preferable because it is excellent in workability and relatively inexpensive. Silicon, silicon nitride, aluminum oxide, or the like can be used.
Further, in FIG. 5, the shape of the opening is an ellipse extending in the length direction of the recharge tube. However, if the weight of the upper half is reduced, the shape of the opening is not necessarily limited to the ellipse extending in the length direction of the recharge tube. For example, it may be an ellipse, a square, a rectangle, other polygons, or a circle extending in the horizontal direction. The maximum diameter of the opening is desirably set to be larger than the minimum diameter of the solid raw material so that the solid raw material in the recharge pipe does not come out of the recharge pipe.

[Embodiment 5]
Next, the recharge tube of the fifth embodiment will be described. The recharging device according to the present embodiment is characterized in that the first embodiment, the modification of the first embodiment, and the second to fourth embodiments are all combined. That is, the lower half of the recharge pipe is thicker than the upper half, the lower end open portion of the recharge pipe is thickened, a reinforcing material is provided in the lower half of the recharge pipe, and the recharge pipe An opaque quartz tube is used for the lower half, a spiral convex portion is provided on the inner wall of the lower half of the recharge tube, and a plurality of openings are provided on the upper half of the recharge tube.
FIG. 6 is an explanatory diagram of the recharge tube of the present embodiment. As shown in FIG. 6, for example, the lower half 301 of the recharge tube made of quartz is thicker than the upper half 303. Further, the lower end opening 305 of the recharge tube made of quartz is built up. A reinforcing member 307 made of quartz is also provided in the lower half region of the recharge pipe made of quartz. Further, a transparent quartz tube 311 is used for the upper half of the recharge tube made of quartz, and an opaque quartz tube 313 is used for the lower half of the region. A spiral convex portion 309 made of quartz is also provided on the inner wall of the lower half region of the recharge tube made of quartz. Further, a plurality of elliptical openings 315 are provided in the upper half of the recharge tube made of quartz.

In this way, by combining elements that improve the fracture toughness of the lower half of the recharge pipe, the fracture toughness of the lower half of the recharge pipe can be made much larger than the upper half. Therefore, at the time of recharging, it is possible to prevent damage to the lower part of the recharge tube, which collides with a solid raw material having a particularly high drop energy, and as a result, it is possible to greatly improve the productivity of single crystals.
Further, by providing an opening in the upper half of the recharge tube, the cost increase can be further suppressed. Further, the point that it is possible to improve the productivity of the single crystal and can further contribute to the reduction of the single crystal cost is the same as in the fourth embodiment.

  In the present embodiment, the first embodiment, the modified example of the first embodiment, and the second to fourth embodiments are combined. However, the required fracture toughness, productivity, and cost of the recharge tube are required. Of course, it is possible to appropriately select an optimal combination of two or more forms.

  Here, solid polycrystalline silicon is used as the solid raw material. However, the present invention is not limited to polycrystal, 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 embodiment described above, a silicon single crystal is described as an example of 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. As long as it is a single crystal, it can be applied to a single crystal such as a GaAs single crystal or an InP single crystal.

The embodiments of the present invention have been described above with reference to specific examples. In the description of the embodiment, the description of the single crystal manufacturing apparatus, the recharge apparatus, the recharge tube, the recharge method, etc. that are not directly necessary for the description of the present invention is omitted, but the required single crystal manufacturing is performed. Elements related to the apparatus, the recharge apparatus, the recharge tube, the recharge method, and the like can be appropriately selected and used.
In addition, all solid material recharge tubes that include elements of the present invention and can be appropriately modified by those skilled in the art and recharge methods using the same are included in the scope of the present invention.

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

(Example)
A recharge tube having an inner diameter of 270 mm and a length of 1400 mm made of quartz was prepared.
As shown in FIG. 7, the lower half 301 of the recharge tube is 6 mm thick, the upper half is 4 mm thick, and the lower half 301 is thick. Moreover, the thickness of the lower end open part was built up to 10 mm. Further, eight reinforcing materials made of quartz having a width of 10 mm and a thickness of 7 mm were welded from a lower end of the lower half of the recharge tube to a region corresponding to ½ of the length of the recharge tube. Furthermore, a total of 20 elliptical openings having a length of 70 mm and a short diameter of 25 mm were provided in an area corresponding to ½ of the length of the recharge tube from the upper end of the upper half of the recharge tube.
The recharge apparatus equipped with this recharge tube was filled with 60 kg of solid silicon single crystal raw material and recharged into a 150 to 300 kg silicon melt remaining in a 32-inch quartz crucible.
As a result of performing the recharge test 12 times by this recharge method, the recharge tube was not cracked, chipped or broken even once.

(Comparative example)
A recharge tube having an inner diameter of 270 mm, a length of 1400 mm, and 4 mm made of quartz was prepared. This recharge tube had a uniform thickness throughout, and was not provided with a reinforcing material and an opening as in the example.
The recharge tube was subjected to a recharge test 12 times under the same conditions as in the example. As a result, the recharge tube was cracked, chipped and broken twice.

  As described above, in the examples, it has been found that by applying the present invention, the fracture toughness of the lower half of the recharge pipe can be increased to effectively suppress cracks, cracks and breakage of the recharge pipe.

3 is an explanatory diagram of a recharge tube according to Embodiment 1. FIG. 6 is an explanatory diagram of a recharge tube according to a modification of the first embodiment. FIG. FIG. 6 is an explanatory diagram of a recharge tube according to a second embodiment. FIG. 10 is an explanatory diagram of a recharge tube according to a third embodiment. FIG. 10 is an explanatory diagram of a recharge tube according to a fourth embodiment. FIG. 10 is an explanatory diagram of a recharge tube according to a fifth embodiment. It is explanatory drawing of the recharge pipe | tube of an Example. It is a typical longitudinal cross-sectional view explaining the silicon single crystal manufacturing apparatus and recharge method which can be used by this invention. It is a typical longitudinal cross-sectional view explaining the silicon single crystal manufacturing apparatus and recharge method which can be used by this invention. It is a typical longitudinal cross-sectional view explaining the silicon single crystal manufacturing apparatus and recharge method which can be used by this invention. It is a typical longitudinal cross-sectional view explaining the silicon single crystal manufacturing apparatus and recharge method which can be used by this invention. It is a typical longitudinal cross-sectional view explaining the silicon single crystal manufacturing apparatus and recharge method which can be used by this invention. It is a typical longitudinal cross-sectional view explaining the silicon single crystal manufacturing apparatus and recharge method which can be used by this invention. It is a typical longitudinal cross-sectional view explaining the silicon single crystal manufacturing apparatus and recharge method which can be used by this invention.

Explanation of symbols

101 Quartz crucible 105 Silicon melt 111 Chamber 127 Subchamber 129 Wire 135 Gate valve
155 Solid polycrystalline silicon raw material 201 Recharge pipe 203 Bottom lid 210 Gap 307 Reinforcement material 309 Spiral convex part 315 Opening part

Claims (7)

A recharge pipe for a solid material provided in a single crystal manufacturing apparatus having a crucible for storing a crystal melt, and for filling the crucible with a solid material,
A solid material recharge tube characterized in that the lower half of the recharge tube has a fracture toughness greater than that of the upper half. A recharge pipe for a solid material provided in a single crystal manufacturing apparatus having a crucible for storing a crystal melt, and for filling the crucible with a solid material,
A solid material recharge tube characterized in that the lower half of the recharge tube is thicker than the upper half. A recharge pipe for a solid material provided in a single crystal manufacturing apparatus having a crucible for storing a crystal melt, and for filling the crucible with a solid material,
A solid material recharge tube, wherein a reinforcing material is provided in a lower half of the recharge tube. A recharge pipe for a solid material provided in a single crystal manufacturing apparatus having a crucible for storing a crystal melt, and for filling the crucible with a solid material,
A solid-state raw material recharge tube, wherein a spiral convex portion is provided on the inner wall of the lower half of the recharge tube.   A recharge pipe for a solid raw material, characterized in that it satisfies the requirements of any two or more of claims 2 to 4.   6. The solid material recharge tube according to claim 1, wherein a plurality of openings are provided in an upper half of the recharge tube. A recharge method using a solid material recharge tube provided in a single crystal manufacturing apparatus having a crucible for storing a crystal melt and filling the crucible with a solid material,
A recharge method using a solid material recharge tube, wherein the lower half of the recharge tube has a fracture toughness greater than that of the upper half.

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