JPH06239632A - Quartz crucible for pulling up silicon single crystal and its production - Google Patents

Abstract

PURPOSE:To obtain a quartz crucible, safely and surely conveyable by a mechanical means and readily installed and removed from a single crystal pulling up apparatus by forming through-holes, recessed parts or protrusions in positions without interfering the installation and removal from a carbon crucible in the upper part of sidewall. CONSTITUTION:The tip 11 of a quartz crucible 10 is regulated to a height protruding from a carbon crucible and through-holes 21, recessed parts or protrusions are formed as an engaging means in the tip 11. A hole for inserting a forming jig is formed in a sidewall of a rotating mold and the forming jig is kept in a state thereof passed through the holes and inserted into a quartz powder layer deposited on the inner peripheral surface of the rotating mold. The quartz powder layer is then thermally melted to perform crucible forming operation. After forming the crucible, the forming jig is pulled out to produce the crucible as a method for producing thereof. Since this crucible has the engaging means for lifting, it can safely and surely be conveyed by a mechanical means and installation and removal from the single crystal pulling up apparatus can readily be carried out. Thereby, labor for operation by the man power can be saved and the crucible can be prevented from being contaminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a quartz crucible used for melting polycrystalline silicon and pulling up single crystal silicon, and a method for producing the same. More specifically, the present invention relates to a quartz crucible provided with engaging means for suspending the crucible for facilitating carrying of the crucible and attachment to a silicon single crystal pulling apparatus, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a silicon single crystal for a semiconductor has a quartz crucible provided in a carbon crucible for heating, and polycrystalline silicon as a raw material is put into the quartz crucible and melted by heating. It is mainly manufactured by the method of pulling crystalline silicon. The shape of the quartz crucible varies depending on the size of the intended silicon single crystal, but typically has a diameter and a height of about 40 cm and has a flat bottom or a gently curved bottom. Such a crucible is mainly manufactured by a rotary mold arc melting method using quartz powder as a raw material, but the quartz crucible itself does not have a means for assisting the transportation because of the manufacturing method. However, as the silicon single crystal becomes larger, the crucible tends to have a larger diameter.
Quartz crucibles with a size of 4 inches and a weight of about 30 kg are manufactured. Due to the weight and size of the quartz crucible, carrying and mounting on a carbon crucible are problems. In other words, since the quartz crucible is a glass product, it is weak against impact, so it is difficult to mechanically grasp and transfer it. Moreover, since the conventional quartz crucible has no means such as a handle, it is suspended and transferred. In addition, since it is carried by workers only by workers, there is a problem of safety and pollution.

Incidentally, a silicon single crystal pulling apparatus in which a through hole is formed in a side wall of a quartz crucible is disclosed in Japanese Patent Publication No. 1-54318.
Although it is described in Japanese Patent Publication (see FIG. 7), the through hole 11 of the quartz crucible in this apparatus is provided for the purpose of releasing the SiO ₂ gas generated at the time of pulling the single crystal silicon to the outside. The carbon crucible 50 that houses the quartz crucible 10 also has a through hole 51 communicating with the through hole 11. Therefore, even if the through hole 11 is used for lifting the quartz crucible, since the through holes 11 and 51 communicate with each other, for example, when a lifting jig is inserted into the through hole 11 from the inner peripheral surface side of the crucible, Carbon crucible 50 at the tip
The quartz crucible 10 cannot be extracted from the carbon crucible 50 because it protrudes into the through hole 51 and engages with the carbon crucible 50. As described above, the quartz crucible has a hole in the upper part of the crucible, but this hole is for the purpose of releasing gas, and the structure cannot be used for lifting the crucible.

Further, Japanese Patent Laid-Open No. 53-88674 also discloses that
Although a single crystal pulling device having a through hole at the upper end of the crucible is described, this through hole is for allowing the melt to overflow to the outside of the crucible, and therefore the upper end of the crucible surrounds the through hole. The annular container is integrally formed, and is clearly different from the lifting engagement hole.

As described above, conventionally, there is no known quartz crucible provided with engaging means for hanging so that the quartz crucible can be easily transferred and detached from the pulling device. This is because the conventional quartz crucible has a relatively small size, and therefore it is sufficient to manually perform the work, and it is not necessary to provide the engaging means to mechanize the handling, and the engaging means is provided due to the limitation of the manufacturing process. It seems that the situation is difficult.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in a conventional quartz crucible, and a hole or an uneven portion for suspending engaging means is provided on the upper side wall of the quartz crucible, and the quartz crucible is transferred to and detached from a pulling device. It is intended to provide a quartz crucible that facilitates.

According to the present invention, there is provided a quartz crucible for pulling a silicon single crystal having the following structure and a method for manufacturing the same. (1) A quartz crucible, which is incorporated in a carbon crucible and is used for pulling a silicon single crystal, characterized in that an engaging means for lifting is formed on an upper portion of a side wall. (2) The quartz crucible according to the above (1), wherein the engaging means is a hole penetrating the side wall of the upper end of the quartz crucible protruding from the carbon crucible. (3) The engaging means is a through-hole, which is above the liquid level of the silicon melt charged in the quartz crucible, and the through-hole is formed in the carbon crucible with the through-hole being inside the carbon crucible. The quartz crucible according to (1) above, which is provided at a position where it is closed by the crucible. (4) The quartz crucible according to (1) above, wherein the engaging means is a protrusion or a recess provided on the inner peripheral surface above the liquid level of the silicon melt. (5) The quartz crucible according to the above (1), wherein the engaging means is a protrusion protruding laterally from the outer peripheral surface of the upper end portion of the quartz crucible located above the carbon crucible. (6) The quartz crucible according to any one of the above (1) to (5), wherein the engaging means is provided at a position symmetrical with respect to the rotation axis of the quartz crucible. (7) In the method of manufacturing a quartz crucible by the rotary molding method, a hole for inserting a molding jig is provided in the side wall of the rotary mold, and the molding jig is formed on the quartz powder layer deposited on the inner peripheral surface of the rotary mold through the hole. With the inserted state, the quartz powder layer is heated and melted to perform the crucible forming operation, and the forming jig is pulled out after the crucible forming to form the hole or recess of the engaging means in the upper side wall of the quartz crucible. A method of manufacturing a quartz crucible for pulling a silicon single crystal, comprising:

[0008]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below with reference to the embodiments shown in the drawings. FIGS. 1 (A) and 1 (B) are external views showing an example in which an engagement hole is provided in an upper side wall of a quartz crucible, and FIGS.
5 is a cross-sectional view showing the lifting state, FIG. 3 is an external view showing an example in which a protrusion is provided as engaging means, FIG. 4 is an example in which a recess is formed as engaging means, and FIGS. 5 (A) (B) (C) Is an external view of the lifting jig, and FIG. 6 is an explanatory diagram of the manufacturing method.

The quartz crucible of the present invention is used for pulling a silicon single crystal. In pulling a silicon single crystal, polycrystalline silicon as a raw material is heated and melted in a state of being charged in a quartz crucible made of high-purity quartz so that impurities are not mixed. This pulling apparatus is provided with a carbon crucible for holding the quartz crucible with good heat conductivity, and further provided with a mechanism for moving the carbon crucible up and down while rotating, and a heating means surrounding the carbon crucible. There is. The quartz crucible is fitted to the carbon crucible,
The single crystal silicon is pulled up from the silicon melt by being gradually lowered while being rotated integrally with the carbon crucible.

As described above, the quartz crucible is fitted in close contact with the inner peripheral surface of the carbon crucible so as to be uniformly heated from the outer periphery thereof. The quartz crucible of the present invention is provided with an engaging means for lifting on the upper side wall thereof so that the quartz crucible can be easily attached to and detached from the carbon crucible and can be easily carried. As the above-mentioned engaging means, an engaging hole or an engaging recess or projection which is penetrated through the side wall of the crucible is formed.

The through hole as the engaging means formed in the upper part of the side wall of the crucible is provided in the carbon crucible in which the quartz crucible is installed when the engaging jig for lifting is inserted into the through hole. It is provided at a position where the jig does not engage. Specifically, as shown in FIGS. 1 and 2, the upper end 11 of the quartz crucible 10 is
Is a height protruding from the carbon crucible 20, and a through hole 12 is provided in an upper end portion 11 protruding from the carbon crucible. Thus, if the through hole 12 is provided in the upper end 11 of the quartz crucible protruding from the carbon crucible 20, as shown in FIG. 2A, when the jig 30 for lifting is engaged with the through hole 12. Since the jig 30 can be inserted from the outer peripheral side of the quartz crucible 10 without being obstructed by the carbon crucible 20, the position of the through hole 12 can be easily confirmed, and the jig 3
Even if the tip of 0 protrudes from the through hole 12, the carbon crucible 2
Since it does not come into contact with 0, the jig 30 and the through hole 12 can be easily engaged with each other, and the quartz crucible 10 can be quickly attached to and detached from the carbon crucible 20.

Further, the engaging through hole 12 is provided with a silicon melt 60 which is charged into the quartz crucible 10 as shown in FIG. 2 (B).
Above the liquid surface level, and at a position where the through hole 12 is closed by the carbon crucible 20 in a state where the quartz crucible 10 is installed in the carbon crucible 20, that is, for degassing provided in the carbon crucible 20. The engaging through hole 12 may be provided at a position where the engaging through hole 12 is not engaged. In this case, the lifting jig 30 is inserted into the through hole 12 from the inner peripheral surface side of the crucible. Since the hole 12 is closed by the inner peripheral surface of the carbon crucible in the state where the quartz crucible 10 is housed in the carbon crucible 20, when the jig 30 is pushed into the hole 12, the tip of the quartz crucible 10 is inserted into the carbon crucible 20. The quartz crucible 10 can be easily pulled out from the carbon crucible 20 without protruding and engaging. If the quartz crucible 10 is suspended with the jig 30 inserted into the through hole 12 so that the tip of the jig 30 does not protrude from the side wall of the quartz crucible, the tip of the engaging jig 10 collides with the carbon crucible 20. Instead, the quartz crucible 10 can be attached to the carbon crucible 20.

The other shape of the engaging means may be the projection 13 as shown in FIG. 3 or the concave portion 14 as shown in FIG. 4 if a sufficient engaging depth can be secured. The engagement projection 13 does not obstruct the attachment and detachment of the quartz crucible 10 to and from the carbon crucible 20, so that the quartz crucible 10 can be prevented.
Is provided on the outer circumference of the upper end portion protruding from the carbon crucible 20. FIG. 3 shows an example in which the engagement projection 13 is provided on the outer periphery of the quartz crucible upper end 11 protruding from the carbon crucible 20.
Further, as shown in FIG. 4, when the engaging recess 14 is provided on the inner peripheral surface of the quartz crucible 10, it is formed above the liquid level of the silicon melt, and on the outer peripheral surface of the quartz crucible 10. Is formed on the upper end portion protruding from the carbon crucible.

It is preferable that all of the through holes 12, the projections 13, and the recesses 14 for engagement are provided symmetrically with respect to the rotation center of the quartz crucible so that the quartz crucible 10 can be stably lifted. FIG. 1 (A) is an example in which the through holes 12 are provided symmetrically, and FIG. 1 (B) is an example in which the holes 12 are provided at three positions at 120 ° intervals with respect to the center of rotation of the quartz crucible. is there. If necessary, the engaging means may be provided at four or more places. Also, these through holes 12, protrusions 13, and recesses 1
The shape of 4 is not particularly limited, and may be an appropriate shape such as a circle, a rectangle, a half moon shape, and an ellipse, but a shape suitable for the engaging jig 30 is preferable.

As an example, if the tip 31 of the engaging jig 30 is formed to project slightly upward and a through hole 12 slightly larger than this tip shape is provided, the engaging jig 30 is provided on the outer peripheral side of the quartz crucible 10. When inserted into the through hole 12 from the
Since the jig tip 31 projects to the inner peripheral surface of the quartz crucible 10 and engages with the through hole 12, there is no risk of the jig 30 coming off the through hole 12.

A concrete example of the lifting jig 30 is shown in FIG.
Shown in (B) and (C). In the example shown in FIG. 5 (A), a three-pronged engaging claw 32 is provided at the lower end of the lifting tool 35. Since each claw 32 is hung from a free joint 33, each claw 3
3 is expanded and the tip 31 is inserted into the through hole 12 or the recess 14 of the quartz crucible 10. Further, FIG. 5B is an example in which the engaging claw 32 is hung from a disk-shaped suspending tool 35. Three engaging claws 32 are provided at equal intervals and are mounted so as to be reciprocally movable laterally. The engaging claw 32 is moved inward, its tip is engaged with the through hole 12 or the concave portion 14 of the quartz crucible 10, and is moved outward from the engaging position to move through the through hole 12 or the concave portion 14. Come off. FIG. 5 (C) shows an example in which the engaging rods 34 are detachably attached to an annular hanging tool 35 that is suspended horizontally, and three engaging rods 34 are inserted at equal intervals toward the center. ing. Hanging equipment 3
The engaging rod 34 is pulled out in advance until the engaging rod 5 is inserted into a position surrounding the upper end of the quartz crucible 10, and then the engaging rod 3 is inserted.
4 is inserted inward, and its tip is engaged with the through hole 12 or the recess 14. These hoists 35 are preferably supported by a hoist or a traveling carriage so that they can be conveyed, and the quartz crucible is hoisted while the engaging claw 32 is engaged with the through hole 12 or the recess 14 of the quartz crucible 10. Transfer to the point. The same hoisting and conveying means can be used for the example in which the engagement projection 13 is provided.

Next, the engaging through hole 12 or the recess 1 is formed.
FIG. 6 shows an example of a method of forming No. 4 of FIG. The illustrated method is a method of simultaneously forming the through holes and the like when the quartz crucible 10 is manufactured by the rotary mold.
A molding hole 41 into which a rod-shaped molding jig (molding rod) 42 is inserted is provided at the upper end of the, and the molding rod 42 is inserted into this hole 41 so that the tip of the molding rod 42 projects into the rotary mold 40. Quartz powder is deposited on the inner peripheral surface of the rotary mold so that the tip of the molding rod 42 is inserted into the quartz powder layer 43.
The quartz powder layer 43 is heated by arc discharge or the like to melt and vitrify from its inner peripheral side. If necessary, the inside of the quartz powder layer is exhausted through the suction passage 44 provided in the rotary mold during heating. After forming the crucible, the forming rod 42 is pulled out to form the through hole 12 at the upper end of the quartz crucible. It should be noted that if the protruding length of the molding rod 42 is made slightly shorter so as not to project from the quartz powder layer 43, the engaging recess can be formed.

The through hole 12 and the recess 14 are
Although the crucible molding can be performed by a core drill or a laser beam without using the above method, the rotational molding method described above does not require punching after the molding, and damage during processing can be avoided. Further, when forming the protrusion of the engaging means, the protrusion may be formed in advance by a high-purity quartz member, and this may be welded to the quartz crucible.

If necessary, the engaging through hole or recess may also have a function of displaying information regarding the quartz crucible. For example, if the arrangement and shape of the through holes and recesses are changed according to the grade (impurity content) of the quartz crucible and the engaging jig of the hanger is shaped to correspond to this, the quartz crucible lifting function as well as the grade identification function Can also be demonstrated.

[0020]

Since the quartz crucible of the present invention has the engaging means for lifting, the quartz crucible can be safely secured by mechanical means,
It can be reliably transported. Further, it can be easily attached to and detached from the single crystal pulling apparatus. Further, since the quartz crucible can be conveyed to a mechanical means, labor saving of manual work and contamination of the quartz crucible can be prevented. Further, in the quartz crucible of the present invention, since no obstacles such as protrusions are formed in the mounting portion with the carbon crucible, the adhesion with the carbon crucible is not impaired, and the thermal conductivity can be uniformly and efficiently maintained. Therefore, it is possible to pull up single crystal silicon having uniform quality and high purity.

[Brief description of drawings]

1A and 1B are external views of a quartz crucible having an engagement hole in an upper side wall.

2A and 2B are cross-sectional views showing a suspended state of a quartz crucible.

FIG. 3 is an external view of a quartz crucible provided with a protrusion of engaging means.

FIG. 4 is a schematic cross-sectional view of a quartz crucible in which a recess of engaging means is formed.

5 (A), (B), and (C) are external views of a lifting jig.

FIG. 6 is an explanatory view of a method for manufacturing a quartz crucible according to the present invention.

FIG. 7 is a schematic sectional view of a conventional silicon single crystal pulling apparatus.

[Explanation of symbols]

10-quartz crucible, 11-upper end of quartz crucible, 12-through hole, 13-protrusion, 14-recess, 20-carbon crucible,
30-engagement jig, 32-engagement claw, 34-engagement rod, 35
-Hanging tool, 40-Rotating mold, 41-Hole, 42-Molding rod, 43-Quartz powder layer.

Claims (7)

[Claims] 1. A quartz crucible, which is incorporated in a carbon crucible and is used for pulling a silicon single crystal, wherein a suspending engagement means is formed on an upper portion of a side wall of the quartz crucible. 2. The quartz crucible according to claim 1, wherein the engaging means is a hole penetrating the side wall of the upper end portion of the quartz crucible protruding from the carbon crucible. 3. The engaging means is a through-hole, which is above the liquid level of the silicon melt charged in the quartz crucible, and the through-hole is provided in a state in which the quartz crucible is contained in the carbon crucible. The quartz crucible according to claim 1, wherein the quartz crucible is provided at a position closed by the carbon crucible. 4. The quartz crucible according to claim 1, wherein the engaging means is a protrusion or a recess provided on the inner peripheral surface above the liquid level of the silicon melt. 5. The quartz crucible according to claim 1, wherein the engaging means is a protrusion protruding laterally from an outer peripheral surface of an upper end portion of the quartz crucible located above the carbon crucible. 6. The quartz crucible according to claim 1, wherein the engaging means is provided at a position symmetrical with respect to the rotation axis of the quartz crucible. 7. A method of manufacturing a quartz crucible by a rotary molding method, wherein a hole for inserting a molding jig is provided in a side wall of the rotary mold, and a quartz powder layer deposited on the inner peripheral surface of the rotary mold through the hole is molded. With the jig inserted, the quartz powder layer is heated and melted to form the crucible, and the molding jig is pulled out after the crucible is formed. A method for manufacturing a quartz crucible for pulling a silicon single crystal, which comprises forming the quartz crucible.