JP2008273788A - Quartz glass crucible for pull-up of silicon single crystal, and method for production of silicon single crystal using the crucible - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a quartz glass crucible for pull-up of silicon single crystal, which has a simple structure and also can prevent the upper end of a body part from falling down inside with a simple structure. <P>SOLUTION: The quartz glass crucible 10 for the pull-up of a silicon single crystal is provided with a body part 12 and a bottom 14, and a peripheral groove 20 is provided on the outer periphery of the body part 12 above an initial melt line L in order to prevent the upper end of the body part 12 from falling down inside during pull-up operation for the silicon single crystal. The groove 20 is preferably provided at such a position as to be downward from the upper end of a carbon susceptor. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a quartz glass crucible for pulling a silicon single crystal and a method for producing a silicon single crystal using the same.

    Conventionally, the production of silicon single crystals for semiconductor production is called the so-called Czochralski method (CZ method), in which silicon polycrystals are melted in a crucible made of quartz glass, and seed crystals are immersed in this silicon melt. A method of growing a silicon single crystal by gradually pulling up a seed crystal while rotating a crucible is widely adopted.

  In the silicon single crystal manufacturing apparatus, as shown in FIG. 4A, a gap of 3 to 5 mm is generally opened between the quartz crucible C1 and the carbon susceptor C2. As shown in FIG. 4 (B), the quartz crucible spreads in the portion below the initial melt line L and the gap is filled, while the upper portion maintains the same position. , The upper end is easy to fall inside.

  In recent years, as the diameter of silicon wafers has increased, the quartz glass crucibles used have also increased in diameter, and as a result, the amount of charge of polycrystal raw materials has increased, and silicon single crystals grown by heaters have grown. Therefore, the heating load on the quartz glass crucible is increasing due to the longer operating time and higher heater output. Further, even in the conventional pulling of 6 ″ and 8 ″ single crystals, the thermal load on the quartz glass crucible tends to be higher than before due to efforts to improve productivity and quality. As a result, regardless of the size of the crucible, the problem that the cylindrical portion of the quartz glass crucible falls inward due to heat load is highlighted.

  As a countermeasure against deformation, a method of crystallizing the glass surface (JP-A-8-2932, JP-A-9-110590, JP-A-2004-131317) or a method of embedding a ring-shaped member (JP-A-2006-96616). However, this is not desirable because it is expected to increase costs.

Japanese Patent Laid-Open No. 2002-47092 proposes a countermeasure for deformation based on a thickness structure, while Japanese Laid-Open Patent Publication No. 2005-41723 proposes a countermeasure for deformation by an appropriate setting of the thickness and viscosity of the straight body portion. If it is changed, it may affect the quality of the crystal, and it cannot be applied to all processes.
JP-A-8-2932 Japanese Patent Laid-Open No. 9-110590 JP 2004-131317 A JP 2006-96616 A JP 2002-47092 A JP-A-2005-41723

  SUMMARY OF THE INVENTION An object of the present invention is to provide a quartz glass crucible for pulling up a silicon single crystal that can be prevented from falling into the inside of the upper end of the straight body portion with a simple structure.

The above object is achieved by a quartz glass crucible for pulling a silicon single crystal having the following configurations (1) to (7) according to the present invention.
(1) In a quartz glass crucible for pulling up a silicon single crystal having a straight body part and a bottom part, the straight body part is prevented from falling inward during the silicon single crystal pulling operation. A quartz glass crucible for pulling a silicon single crystal, characterized in that a circumferential groove is provided on the outer periphery and above the initial melt line.
(2) The silicon according to (1), wherein the groove is provided at a position below the upper end of the carbon susceptor when the quartz glass crucible is incorporated into a silicon single crystal manufacturing apparatus having a carbon susceptor. A quartz glass crucible for single crystal pulling.
(3) The groove has a lower depth of 1 mm or 5% of the thickness of the straight body, whichever is larger, and the upper limit is 35%. A quartz glass crucible for crystal pulling.
(4) The quartz glass crucible for pulling a silicon single crystal according to any one of (1) to (3), wherein the groove has a width on the outer surface of the straight body portion of 1 to 10 mm.
(5) The quartz glass crucible for pulling a silicon single crystal according to (4), wherein the groove has a width of 1 to 5 mm on an outer surface of the straight body portion.
(6) The quartz glass crucible for pulling a silicon single crystal according to any one of (1) to (5), wherein the groove has a V shape.
(7) A method for producing a silicon single crystal, wherein the silicon single crystal is pulled using the quartz glass crucible for pulling a silicon single crystal according to any one of (1) to (6).

  In the silica glass crucible for pulling up a silicon single crystal of the present invention, since the groove as described above is provided on the outer periphery of the straight body portion, the upper end portion faces outward with the groove as a base point. Can be prevented.

  The silica glass crucible for pulling a silicon single crystal of the present invention has a simple structure in which a groove is simply provided on the outer periphery of a crucible created under the same conditions as the conventional one, and the usage conditions are adjusted because there is no change in wall thickness. There is an advantage that it can be used without having to do it. In terms of cost, it can be handled with a simple apparatus, which is advantageous.

Japanese Patent Application Laid-Open No. 2004-299927 proposes to provide a minute groove on the outer surface, but the purpose is to increase the frictional resistance, even if it is effective for buckling and sinking. It does n’t work for falling down. Moreover, the groove | channel property differs from the groove | channel of this invention.
JP 2004-299927 A

  Hereinafter, a quartz glass crucible for pulling a silicon single crystal according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic sectional view of a quartz glass crucible 10 for pulling a silicon single crystal according to an embodiment of the present invention.
As shown in FIG. 1, the basic form of the quartz glass crucible 10 for pulling up a silicon single crystal may be the same as a normal one, and includes a straight body portion 12 and a bottom portion 14. Further, the layer structure is composed of an outer layer portion 16 of a translucent glass layer containing a large number of bubbles, and an inner layer portion 18 of a transparent quartz glass layer having a smooth surface with no bubbles formed on the inner surface of the outer layer portion 16. It has become.

The quartz glass crucible 10 for pulling a silicon single crystal is not particularly limited, but is particularly useful for those having a diameter of 22 inches or more.

  In the quartz glass crucible 10 for pulling up the silicon single crystal, the outer periphery of the straight barrel portion 12 is provided on the outer periphery of the straight barrel portion in order to prevent the upper end of the straight barrel portion 12 from falling inward during the silicon single crystal pulling operation. A circumferential groove 20 is provided above the line L. In other words, the groove 20 serves as a base point that faces outward so as to prevent the upper end of the straight body portion 12 from falling inward. The presence of this groove is a characteristic point of the quartz glass crucible for pulling up a silicon single crystal of the present invention, and may be any other structure and configuration. The position of the groove 20 is preferably about 5 to 30 mm above the initial melt line L, although it depends on the size of the crucible. The reason why the position of the groove 20 is above the initial melt line is that when the position is below the initial melt line, the portion of the straight body portion 12 where the groove 20 is provided expands and is pressed against the carbon susceptor. This is because it becomes difficult to make the upper end of the straight body portion outward from the base point.

  As shown in FIG. 2A, the groove 20 is formed when the quartz single crystal pulling crucible 10 for pulling a silicon single crystal is incorporated in a silicon single crystal manufacturing apparatus 30 including a carbon susceptor 32. It is preferable to be provided at a position below the upper end of the. By providing the groove 20 below the upper end of the carbon susceptor 32, it is possible to prevent the silicon single crystal pulling quartz glass crucible 10 from coming into contact with the carbon susceptor 32 and falling down when the upper end of the quartz glass crucible 10 faces outward (FIG. 2). (See (B)).

  It is preferable that the groove 20 has a depth lower limit of 1 mm or 5% of the thickness of the straight body, whichever is larger, and an upper limit of 35%. If the depth is less than 1 mm or less than 5% of the thickness of the straight body part, a satisfactory effect cannot be exhibited. If the depth exceeds 35% of the thickness of the straight body part, there is a risk of damage during handling. Arise.

The groove 20 preferably has a width on the outer surface of the straight body portion 12 of 1 to 10 mm, particularly 1 to 5 mm. If the width is less than 1 mm, a satisfactory effect may not be obtained. If the width exceeds 10 mm, the base point is not stable.
The shape of the groove 20 may be V-shaped, U-shaped, U-shaped, or the like, but is most preferably V-shaped. The V-shape is the most stable base point.

  Note that the number of the grooves 20 is not limited to one, and may be a plurality.

The groove 20 can be formed as follows.
Although there is no particular limitation, in order to make a crucible into a product, it is necessary to cut the crucible to the required height or chamfer the end face. Machines used for this work are generally targeted. Since it has a mechanism for holding and rotating the crucible, it can be easily realized by using this, for example, by pressing a tool having a V-shaped tip to a predetermined depth.

  The quartz glass crucible 10 for pulling a silicon single crystal according to the embodiment of the present invention as described above is protected by a carbon susceptor 32 in a silicon single crystal manufacturing apparatus 30 as shown in FIG. A crucible drive mechanism (not shown) is supported on the support shaft 36 so as to be rotatable and movable up and down. Then, in the quartz glass crucible 10 for pulling up the silicon single crystal, the polycrystalline silicon raw material is melted by heating with the heater 38 to melt the seed crystal 44 held in the seed holder 42 as the raw material melt 40. After coming into contact with the liquid 40, the silicon single crystal S is grown by pulling it up while being rotated by the wire 46. Then, the grown silicon single crystal S is accommodated in a pulling chamber 48 connected to the main chamber 34 and taken out.

  In the silicon single crystal manufacturing apparatus 30 as described above, the position of the groove 20 provided in the silica glass crucible 10 for pulling up the silicon single crystal is set to a position below the upper end of the carbon susceptor 32.

EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not limited to these.
In the example, the silicon single crystal manufacturing apparatus shown in FIG. 3 was used, but the position (height position), depth, width, and shape of the groove 20 provided in the quartz glass crucible 10 for pulling up the silicon single crystal were changed. As shown in Table 1, ten crucibles with various changes were made, and the silicon single crystal was pulled up. The crucible size was 24 inches (609.6 mm) in diameter, 400 mm in height, and the thickness of the straight body portion was 12 mm. In addition, 5% of the straight body thickness is 0.6 mm, and 35% is 4.2 mm. The amount of silicon polycrystalline raw material charged to the crucible was 150 kg, the initial melt line was located 120 mm below the upper end surface of the crucible, and the upper end of the carbon susceptor was located 60 mm below the upper end surface of the crucible.
In Comparative Example 2, similarly to the Example, ten grooves 20 shown in Table 1 were provided in the silica glass crucible 10 for pulling up the silicon single crystal, 10 pieces were formed, and the silicon single crystal was pulled up. Comparative Example 1 shows the evaluation results when the crucible has no grooves.

結果の評価は次の通りである。
◎ 内側へ変形したルツボは無し。
○ 内側への変形が１個または２個発生。但しいずれも操業上問題ないレベル。
△ 内側への変形が３〜５個発生。但しいずれも操業上問題ないレベル。
× 内側への変形が８個以上発生。更に内側へ倒れ込み、操業を中止せざるを得なかったものも発生。
以上から本発明の効果が明らかである。 Table 1 shows the results of Examples and Comparative Examples.

The evaluation of the results is as follows.
◎ No crucible deformed inward.
○ One or two inward deformations occurred. However, both levels are not problematic for operation.
△ 3-5 inward deformations occurred. However, both levels are not problematic for operation.
× 8 or more inward deformations occurred. Some of them fell further inward and had to stop operation.
From the above, the effect of the present invention is clear.

It is a schematic sectional drawing of the quartz glass crucible for silicon single crystal pulling by embodiment of this invention. (A) is an explanatory view for explaining the positional relationship between a silica glass crucible for pulling up a silicon single crystal shown in FIG. 1 and a carbon susceptor of a silicon single crystal manufacturing apparatus incorporating the silica glass crucible. FIG. 5 is an explanatory diagram for explaining a state in which the upper end of the straight body portion is directed outward by a groove provided in the straight body portion of the quartz glass crucible. It is the schematic of the silicon single crystal manufacturing apparatus incorporating the quartz glass crucible for silicon single crystal pulling shown in FIG. (A) is an explanatory view for explaining the positional relationship between a conventional silica glass crucible for pulling up a silicon single crystal without a groove in a straight body portion and a carbon susceptor of a silicon single crystal manufacturing apparatus incorporating the quartz glass crucible; (B) is explanatory drawing for demonstrating the state which the upper end of the straight body part of the quartz glass crucible fell inward.

Explanation of symbols

10 Silica glass crucible for pulling up silicon single crystal 12 Straight body 14 Bottom 20 Groove 30 Silicon single crystal production device 32 Carbon susceptor 34 Main chamber 36 Support shaft 38 Heater 40 Raw material melt 42 Seed holder 44 Seed crystal 46 Wire 48 Pull up Chamber

Claims (7)

  In a silica glass crucible for pulling up a silicon single crystal having a straight body and a bottom, the upper end of the straight body is prevented from falling inward during the silicon single crystal pulling operation. A quartz glass crucible for pulling up a silicon single crystal, characterized in that a circumferential groove is provided above the initial melt line.   The silicon single crystal pulling of claim 1, wherein when the quartz glass crucible is incorporated into a silicon single crystal manufacturing apparatus having a carbon susceptor, the groove is provided at a position below the upper end of the carbon susceptor. Quartz glass crucible for use.   The quartz glass for pulling up a silicon single crystal according to claim 1 or 2, wherein the groove has a lower limit of the depth of 1 mm or 5% of the thickness of the straight body part, which is larger, and an upper limit of 35%. Crucible.   4. The quartz glass crucible for pulling a silicon single crystal according to claim 1, wherein the groove has a width of 1 to 10 mm on an outer surface of the straight body portion.   The quartz glass crucible for pulling a silicon single crystal according to claim 4, wherein the groove has a width of 1 to 5 mm on an outer surface of the straight body portion.   The quartz glass crucible for pulling a silicon single crystal according to any one of claims 1 to 5, wherein the groove has a V shape. A method for producing a silicon single crystal, comprising pulling up the silicon single crystal using the quartz glass crucible for pulling up a silicon single crystal according to any one of claims 1 to 6.

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