JP3198914B2 - Graphite crucible for pulling single crystal and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a graphite crucible for pulling a single crystal and a method for producing the same, and more particularly, to supporting a quartz crucible when pulling a single crystal by the Czochralski method (hereinafter referred to as CZ method). The present invention relates to a graphite crucible for pulling a single crystal and a method for producing the same.

[0002]

2. Description of the Related Art There are various crystal growth methods, one of which is a rotation pulling method represented by, for example, a CZ method.

FIG. 5 is a cross-sectional view schematically showing a conventional single crystal pulling apparatus used in the CZ method.
Reference numeral 1 denotes a single crystal pulling crucible disposed in the chamber 58.

The single crystal pulling crucible 41 is a graphite crucible 4 having a bottomed cylindrical shape and set on a crucible receiving base 43a.
3 and a quartz crucible 42 fitted inside the graphite crucible 43, and the crucible pedestal 43a is supported by a support shaft 44 that rotates at a predetermined speed. A heater 45 of a resistance heating type is provided outside the single crystal pulling crucible 41, and a heat insulating cylinder 46 made of graphite is provided concentrically outside the crucible 41. A predetermined amount of crystal is provided inside the quartz crucible 42. Melt 4 obtained by melting raw materials by heater 45
7 is filled. A lifting shaft 48 made of a lifting rod or a wire that rotates at a predetermined speed in a direction indicated by an arrow in the figure is suspended from the center axis of the graphite crucible 43.
The seed crystal 50 is attached via the.

When the single crystal 51 is pulled up, the seed crystal 50 attached to the tip of the pulling shaft 48 is brought into contact with the surface of the molten liquid 47, and a predetermined axis is set to the same axis as the supporting shaft 44 in the opposite direction or the same direction. Lifting shaft 48 while rotating at speed
By pulling up, the melt 47 is solidified and the single crystal 51 grows.

In the above single crystal pulling apparatus, the quartz crucible 42 fitted in the graphite crucible 43 is a single crystal 51
Is heated to a high temperature during the lifting process,
It adheres closely to the graphite crucible 43. Since the coefficient of thermal expansion of graphite is about 10 times larger than the coefficient of thermal expansion of quartz, contraction in the radial direction during cooling is larger in the graphite crucible 43 than in the quartz crucible 42. Due to the difference in the amount of shrinkage between the two, the graphite crucible 43 during cooling becomes a quartz crucible 42 with a small amount of shrinkage.
Further receiving the internal pressure, a tensile stress acts on the graphite crucible 43.

In recent years, the diameter of the single crystal 51 has been increased in order to obtain the single crystal 51 with a high yield.
2, and the size of the graphite crucible 43 is increasing. Due to the enlargement of the graphite crucible 43 and the like, the difference in the amount of contraction in the radial direction between the quartz crucible 42 and the graphite crucible 43 during cooling after pulling the single crystal 51 increases, and the tensile stress acting on the graphite crucible 43 increases. , Deformation, cracking or breakage (hereinafter also referred to as breakage) are likely to occur, and the number of times that the same graphite crucible 43 can be used repeatedly is decreasing.

In order to cope with the above problem, recently, graphite crucibles having various shapes which are divided into two or more vertically are used.

As another crucible for solving the above problem, there is disclosed a graphite crucible for pulling a single crystal in which a carbon fiber reinforced carbon composite material is partially used (Japanese Utility Model Publication No. 3-43250). Gazette, Registered Utility Model Gazette No. 3
012299). FIG. 6 is a cross-sectional view schematically showing a graphite crucible for pulling a single crystal disclosed in Japanese Utility Model Publication No. 3-43250.

The graphite crucible 52 for pulling a single crystal is
The straight body portion 53 and the R portion 54 continuing from the straight body portion 53 are formed of an integrated carbon fiber reinforced carbon composite material (hereinafter, also referred to as C / C material), and are made of isotropic graphite material. The bottom 55 is fitted to the R portion 54.

However, in the graphite crucible 52 for pulling a single crystal shown in FIG. 6, peeling occurs on the surface layer at the fitting surface 54a with the quartz crucible (not shown) near the R portion 54 during repeated use. There was a problem of doing. This peeling occurs because the C / C material and the quartz react on the fitting surface 54a and S
iO is generated, and the C / C material on the inner surface becomes S
This is due to iC conversion. That is, since the thermal expansion coefficient of SiC is about 10 times the thermal expansion coefficient of the C / C material, if the formation of SiC proceeds at the fitting surface 54a near the R portion 54, the SiC conversion layer and the SiC conversion layer during cooling after the single crystal is pulled up. Thermal distortion occurs between the SiC conversion layer and the C / C material layer located outside the SiC conversion layer.
The C / C material has a large strength in the fiber direction, but a small strength in the fiber layer direction, that is, the radial direction of the single crystal pulling graphite crucible 52. If thermal strain occurs, separation occurs between the fiber layers.

The single crystal pulling graphite crucible 5
2 has a fitting portion, so that SiO generated by the reaction between the carbon material and the quartz crucible enters the fitting surface 55a and reacts with the graphite on the bottom 55, and the bottom 55 is locally worn near the fitting surface 55a. There was a problem of doing.

Further, the molten liquid 47 remaining at the bottom of the quartz crucible after pulling the single crystal is solidified and expanded at the time of cooling, and the quartz crucible is expanded accordingly. Pressure acts. Therefore, if the bottom portion 55 is made of graphite having a low strength, breakage is likely to occur.

As described above, when the graphite crucible 52 for pulling a single crystal is formed by combining a C / C material and graphite, the above-described various problems occur. As a method of solving these problems, it is conceivable that the entire graphite crucible for pulling a single crystal is made of a C / C material. However, in this case, the following problem occurs.

[0015]

There are two methods for producing a graphite crucible for pulling a single crystal in which the whole crucible is made of a C / C material. The first method is as follows. First, a strand obtained by bundling continuous carbon fibers (hereinafter simply referred to as continuous carbon fibers) is immersed in a low-viscosity binder obtained by dissolving a resin represented by a thermosetting resin with a solvent, and then wound around a crucible-shaped mandrel. And then heat cured. Next, a cutting process or the like is performed on the cured product to produce a crucible-shaped molded product (filament winding method). Next, the molded body was once placed in an inert gas at 1000
C. for heating and carbonization, and if necessary, impregnation with coal tar pitch or the like, and then heating at a high temperature of about 2500.degree. C. to carbonize (graphitize) the whole. Next, the production of the single crystal pulling crucible is completed by subjecting the carbonized crucible to a purification treatment or the like. The carbonization (graphitization) treatment at a high temperature is performed a plurality of times as necessary.

The second method is a method in which a carbon fiber cloth impregnated with a resin or the like is stuck to a crucible mold to produce a molded body, and then a crucible is manufactured in the same manner as in the first method.

However, the cost of the graphite crucible for pulling a single crystal is extremely low in the second method because the carbon fiber cloth itself is expensive and it is difficult to automate the molding process. There was a problem of getting high.

The first method uses an inexpensive continuous carbon fiber as compared with a continuous carbon fiber cloth and can produce a compact by automatic winding, so that an inexpensive C / C material can be efficiently produced. A graphite crucible for pulling a single crystal can be manufactured.

FIG. 7 is a front view schematically showing a state in which continuous carbon fibers are wound around a mandrel by the filament winding method, and the angle between the horizontal direction of the crucible and the winding direction of the continuous carbon fiber filaments. (Hereinafter, also simply referred to as a winding angle) is represented by θ.

The central part 61 of the mandrel 60 has the same shape as the inner wall of the straight body of the single crystal pulling crucible.
The right end 62 and the left end 63 have substantially the same shape as the bottom inner wall. Further, a rotating rod 64 for supporting the rotation of the mandrel 60 is attached to the center of the left end 63. When winding the continuous fiber, the rotating rod 64 is gripped by a rotary chuck and rotated in the form of a cantilever to wind the continuous carbon fiber to which the binder is attached. When winding the carbon fiber cloth, it is not necessary to rotate the mandrel.

Since the single crystal pulling crucible is usually composed of a short straight body and a flat bottom like a mirror plate,
In order to wind the continuous carbon fiber around the entire crucible-shaped mandrel, the winding angle (θ) as shown in FIG.
It is necessary to insert a so-called helical winding that is wound so as to be about 90 °. However, in a crucible in which a formed body is simply produced by only the helical winding, there is a problem that the crucible shrinks in the radial direction in the carbonization step, and the diameter of the crucible is reduced. This is because almost no shrinkage in the direction of the continuous carbon fiber occurs in the carbonization step, but shrinkage in the direction (circumferential direction) perpendicular to the continuous carbon fiber is caused by the shrinkage of the matrix such as resin. This is because the material shrinks largely in the radial direction. If the diameter of the crucible manufactured by the shrinkage becomes smaller than the set size, it becomes impossible to insert a quartz crucible.

In order to prevent the above-mentioned shrinkage phenomenon, not only the above-mentioned helical winding but also a formed body employing winding of continuous carbon fibers having a winding angle (θ) smaller than 90 ° is used. Further, there is a case where a formed body using a so-called parallel winding together, in which continuous carbon fibers are wound so that the winding angle (θ) becomes substantially 0 °, is also used. However, also in this case, since the amount of shrinkage in the carbonization step differs depending on the winding angle (θ), there is a problem that peeling occurs between fiber layers and strength is reduced.

The present invention has been made in view of the above problems, and is an inexpensive, high-dimensional accuracy, durable single crystal pull-up which does not cause separation or the like between fiber layers, manufactured by using a filament winding method. It is an object of the present invention to provide a graphite crucible for use and a method for producing the same.

[0024]

In order to achieve the above object, a graphite crucible for pulling a single crystal according to the present invention (1) is a graphite crucible for pulling a single crystal made of a continuous carbon fiber reinforced carbon material. At least the continuous carbon fiber having an angle of −45 ° to + 45 ° with respect to the horizontal direction is disposed on the inner peripheral portion of the straight body portion, and the other portion has an angle of −45 ° or less or + 45 ° or more with respect to the horizontal direction. Is characterized in that continuous carbon fibers having

FIG. 1 is a graph showing the relationship between the winding angle (θ) of continuous carbon fibers and the amount of shrinkage in the radial direction in the carbonization step when producing a graphite crucible for pulling a single crystal by the filament winding method. is there. As is clear from the graph shown in FIG. 1, the winding angle (θ) of the continuous carbon fiber hardly shrinks in the range of −45 to + 45 °, but the winding angle (θ) of the continuous carbon fiber is −45.
When the angle is smaller than 0 ° or larger than + 45 °, the contraction amount in the radial direction sharply increases.

According to the graphite crucible (1) for pulling a single crystal having the above structure, continuous carbon fibers are formed so that the winding angle (θ) is at least in the range of −45 to + 45 ° around the inner periphery of the straight body. Almost no deformation due to shrinkage. In addition, a portion other than the inner peripheral portion of the straight body portion (hereinafter, referred to as an inner peripheral portion)
(Referred to as the outer peripheral portion), the continuous carbon fibers are arranged so that the winding angle (θ) is equal to or less than -45 ° or greater than + 45 °. And there is no peeling. Further, since the single crystal pulling graphite crucible is formed integrally and has no fitting portion, there is no occurrence of SiC or the like in the fitting portion when the single crystal is pulled, and the fiber layers adhere to each other. Therefore, no peeling occurs on the surface layer even after long-term use.

A graphite crucible for pulling a single crystal according to the present invention (2) is a graphite crucible for pulling a single crystal made of a continuous carbon fiber reinforced carbon material, wherein a continuous carbon fiber cloth is arranged at least on an inner peripheral portion of a straight body portion. , Characterized in that continuous carbon fibers having an angle of -45 ° or less or + 45 ° or more with respect to the horizontal direction are arranged in other portions.

According to the graphite crucible (2) for pulling a single crystal having the above structure, since the continuous carbon fiber cloth is disposed at least on the inner peripheral portion of the straight body portion, there is no deformation due to shrinkage. The winding angle (θ) is -45 ° on the outer periphery.
Since the continuous carbon fibers are arranged so as to be equal to or lower than + 45 ° or more, the fiber layers are in close contact with each other and there is no peeling. In addition, since the single crystal pulling graphite crucible is formed integrally and does not have a fitting portion, there is no occurrence of SiC or the like in the fitting portion when the single crystal is pulled, and the fiber layers adhere to each other. Therefore, even when used for a long time, the surface layer does not peel off.

The method (1) for producing a graphite crucible for pulling a single crystal according to the present invention is a method for producing a graphite crucible for pulling a single crystal by a filament winding method using continuous carbon fibers. After winding the continuous carbon fiber at an angle of -45 ° to + 45 ° with respect to the horizontal direction around at least a portion corresponding to the inner peripheral portion of the crucible straight body portion, −
It is characterized in that continuous carbon fibers are wound at an angle of 45 ° or less or + 45 ° or more.

According to the method (1) for producing a graphite crucible for pulling a single crystal, the continuous carbon fiber is formed so that the winding angle (θ) is at least in the range of -45 to + 45 ° around the inner periphery of the straight body. In the carbonization step, the amount of shrinkage of the inner peripheral portion in the radial direction is extremely small, and the single crystal pulling graphite crucible hardly deforms. Further, the winding angle (θ) is -45 ° or less or +4
As continuous carbon fiber is wound so as to be 5 ° or more,
The outer peripheral portion contracts in the radial direction during the carbonization process. However, the shrinkage tightens the inner peripheral portion to bring the fiber layers into close contact with each other, so that peeling does not occur. Further, the graphite crucible for pulling a single crystal manufactured by the above method is formed integrally and does not have a fitting portion. Therefore, when the single crystal is pulled, SiC conversion or the like does not occur in the fitting portion, and Since the fiber layers are in close contact with each other, the surface layer does not peel even after long-term use.

The method (2) for producing a graphite crucible for pulling a single crystal according to the present invention is a method for producing a crucible for pulling a single crystal by using a continuous carbon fiber and winding the continuous carbon fiber around a mold. In the crucible manufacturing method, a continuous carbon fiber cloth is wound around at least a portion corresponding to an inner peripheral portion of a straight body portion, and continuous carbon fibers are wound around other portions at an angle of -45 ° or less or + 45 ° or more with respect to a horizontal direction. It is characterized by winding.

According to the method (2) for producing a graphite crucible for pulling a single crystal, since a continuous carbon fiber cloth is wound around at least the inner periphery of the straight body, the inner periphery contracts in the radial direction in the carbonization step. No deformation of the graphite crucible for single crystal pulling occurs. In addition, since the continuous carbon fibers are wound around the outer peripheral portion so that the winding angle (θ) is −45 ° or less or + 45 ° or more, the outer peripheral portion contracts in the radial direction in the carbonization step. However, the shrinkage tightens the inner peripheral portion and makes the layers of the carbon fiber adhere to each other, so that no peeling occurs. Further, the graphite crucible for pulling a single crystal manufactured by the above method is integrally formed and has no fitting portion, so that when pulling the single crystal, SiC conversion or the like does not occur in the fitting portion, and Since the fiber layers are in close contact with each other, the surface layer does not peel even after long-term use.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a graphite crucible for pulling a single crystal and a method for manufacturing the same according to the present invention will be described below with reference to the drawings.

FIG. 2A is a plan view schematically showing a graphite crucible for pulling a single crystal according to the embodiment.
(B) is a partially cutaway front view, in which the left part is a cross section.

The winding angle (θ) of the inner peripheral part 11a of the straight body part 11 of the single crystal pulling graphite crucible 10 is -4.
The continuous carbon fibers 13 are arranged so that 5 ≦ θ ≦ + 45 °. Also, the outer peripheral portion 11b and the bottom portion 1 of the straight body 11
2 has a winding angle (θ) of θ ≦ −45 ° or θ ≧ 4
The continuous carbon fibers 13 are arranged at 5 °. However, the continuous carbon fibers 13 may be arranged on a part of the outer peripheral portion 11b of the straight body portion 11 such that the winding angle (θ) is −45 ≦ θ ≦ + 45 °. In addition, continuous carbon fiber 1
Portions other than 3 are made of graphite produced by performing a heat treatment after filling with resin or coal tar pitch.

Graphite crucible 1 for pulling a single crystal having the above structure
In the case of manufacturing the carbon fiber 0, the continuous carbon fiber 13 immersed in the binder is wound around the mandrel.
The continuous carbon fibers 13 are wound around a portion corresponding to the inner peripheral portion 11a of the first so that the winding angle (θ) becomes −45 ≦ θ ≦ + 45 °. After this winding is completed, the winding angle (θ) is θ ≦ −45 ° or θ ≧ 45 ° around the portion corresponding to the outer peripheral portion 11b and the portion corresponding to the bottom portion 12.
The continuous carbon fiber 13 is wound so that When the winding angle (θ) is about −10 ° ≦ θ ≦ about + 10 °,
Since the continuous carbon fiber 13 slips at the boundary between the straight body portion 11 and the bottom portion 12, a large number of pins are set up at the boundary to prevent the continuous carbon fiber 13 from slipping, and after forming a molded body, And remove the carbon fibers wrapped around the pins. Thereafter, the graphite crucible 10 for pulling a single crystal is manufactured by a method similar to the method described in the section of "Prior Art".

The smaller the winding angle (θ) of the continuous carbon fiber 13 in the inner peripheral portion 11a, the less likely it is to deform in the carbonization step, and the higher the effect of preventing deformation of the outer peripheral portion 11b due to shrinkage. Therefore, the winding angle (θ) of the continuous carbon fiber 13 is preferably in the range of −45 ° to + 45 °, and −15 ° to + 45 °.
The range of + 15 ° is more preferable. Furthermore, it is most preferable that the winding angle (θ) of the continuous carbon fibers 13 is 0 °, that is, the continuous carbon fibers 13 are wound in parallel in the horizontal direction because of the ease of winding the continuous carbon fibers 13. However, it is difficult to wind the bottom portion 12 at a winding angle (θ) of 0 ° or an angle close thereto because the continuous carbon fibers 13 slip. Therefore, the winding angle (θ) of the portion corresponding to the bottom portion 12 is θ ≦ −45, similarly to the case of winding the portion corresponding to the outer peripheral portion 11b.
And the continuous carbon fiber 13 is wound so that θ or θ ≧ 45 °.

The thickness of the inner peripheral portion 11a is preferably about 1/6 to 1/2 of the thickness of the straight body portion 11. When the thickness of the inner peripheral portion 11a is less than 1/6 of the thickness of the straight body portion 11, the effect of suppressing the deformation of the single crystal pulling graphite crucible 10 becomes small, while the thickness of the inner peripheral portion 11a is reduced. 1 / th of the thickness of the torso 11
If it exceeds 2, the effect of tightening the inner peripheral portion 11a due to the contraction of the outer peripheral portion 11b in the carbonization step and bringing the fiber layers into close contact with each other is reduced. However, when the continuous carbon fiber 13 is wound around the portion corresponding to the inner peripheral portion 11a in the horizontal direction,
Since the deformation preventing effect is large, the inner peripheral portion 11a is
It is sufficient that the thickness is about 1/10 or more of the thickness. In addition, the outer peripheral portion 1
For 1b, it is not necessary to wind all the continuous carbon fibers 13 so that the winding angle becomes θ ≦ −45 ° or θ ≧ 45 °. A continuous carbon fiber layer or a continuous carbon fiber cloth layer in the range of -45 to 45 [deg.] May be arranged between a plurality of layers. However, in this case, in order to secure the tightening at the outer peripheral portion 11b, it is preferable that the thickness of the carbon fiber layer disposed therebetween is as thin as 1/10 or less of the thickness of the crucible.

Examples of the continuous carbon fibers 13 include various types of continuous carbon fibers 13 such as a PAN type and a pitch type. These continuous carbon fibers 13 are usually used in the form of a strand in which hundreds to thousands of continuous carbon fibers 13 are bundled. A binder for the continuous carbon fibers 13, that is, a binder for dipping before the continuous carbon fibers 13 are wound around the mandrel, or a molded body around which the continuous carbon fibers 13 are wound and subjected to a hardening treatment or a low-temperature carbonization treatment is dipped. Examples of the binder include a thermosetting resin represented by a phenol resin and a furan resin, coal tar pitch, and the like. The thermosetting resin is dissolved in a solvent and used in a liquid state.

FIG. 3A is a plan view schematically showing a single crystal pulling graphite crucible according to another embodiment.
(B) is a partially cutaway front view, in which the left part is a cross section.

In the present embodiment, continuous carbon fibers 13 are arranged on the inner peripheral portion 21a of the straight body 21 of the graphite crucible 20 for pulling a single crystal so that the winding angle (θ) is 0 °, that is, horizontal. And the outer peripheral portion 21 of the straight body portion 21
b and the bottom 22 have a winding angle (θ) of θ ≦ −45.
° or θ ≧ 45 ° is provided with the continuous carbon fibers 13.

When manufacturing the single crystal pulling graphite crucible 20, a portion corresponding to the inner peripheral portion 21a of the straight body portion 21 is
Continuous carbon fiber 1 so that the winding angle (θ) is 0 °
Except for winding 3, it is the same as the case of manufacturing the graphite crucible 10 for pulling a single crystal shown in FIG. 2. In the method of manufacturing the graphite crucible 20 for pulling a single crystal, since the continuous carbon fibers 13 are wound horizontally around the inner peripheral portion 21a,
No shrinkage occurs in the radial direction in the carbonization step. In addition, as in the case of the graphite crucible for pulling a single crystal shown in FIG. 2, the fiber layers adhere to each other.

FIG. 4A is a plan view schematically showing a graphite crucible for pulling a single crystal according to still another embodiment, and FIG. 4B is a partially cutaway front view showing a left part. Is a cross section.

In this embodiment, the continuous carbon fiber cloth 15 is disposed on the inner peripheral portion 31a of the straight body portion 31 of the graphite crucible 30 for pulling a single crystal, and the outer peripheral portion 31b and the bottom portion 32 of the straight body portion 31 are provided. Has a winding angle (θ) of θ ≦ -4
The continuous carbon fibers 13 are arranged so as to satisfy 5 ° or θ ≧ 45 °. In this case, since the inner peripheral portion 31a hardly shrinks in the radial direction in the carbonization step, the thickness of the inner peripheral portion 31a may be about 1/10 or more of the thickness of the straight body portion 31.

When manufacturing the graphite crucible 30 for pulling a single crystal, a portion corresponding to the inner peripheral portion 31a of the straight body portion 31 is
Except for winding the continuous carbon fiber 13 cloth immersed in the binder into a predetermined thickness, it is the same as the case of manufacturing the graphite crucible 10 for pulling a single crystal shown in FIG.
Examples of the continuous carbon fiber 13 cloth to be used include 2-D cloth and UD cloth produced by various weaving methods. Among these, plain weave 2-D cloth in which the continuous carbon fiber 13 is orthogonally cross-woven. Cloth is preferred because it has little anisotropy.

[0046]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a graphite crucible for pulling a single crystal and a method for producing the same according to the present invention will be described below. As a comparative example, a conventional crucible for pulling a single crystal and a manufacturing method thereof will be described.

(1) Graphite crucible for pulling a single crystal to be produced and its dimensions Graphite crucible for pulling a single crystal to be produced: Table 1 below
Shown in Dimensions of single crystal pulling crucible Inner diameter: 309 mm, height: 220 mm, thickness of straight body: 10 mm, thickness of bottom: 8 to 15 mm (2) Raw materials and manufacturing conditions Types of continuous carbon fibers 13 PAN-based high strength Strand of continuous carbon fiber (6000 filaments) Binder: A solution of high-purity phenol resin dissolved in a solvent Curing condition of resin Curing temperature: 200 ° C Carbonization condition Carbonization furnace: Firing furnace packed with coke powder Atmosphere: Nitrogen atmosphere First and second heating temperature: 1000 ° C. Third heating temperature: 2500 ° C. Before the second and third heating, the crucible compact was depressurized in a coal tar pitch. Thereafter, pressure impregnation was performed. Purification treatment: high temperature halogen gas (3) Durability test Examples 1 to 4 were performed using the single crystal pulling apparatus shown in FIG.
6 and the graphite crucibles for pulling single crystals according to Comparative Examples 1 to 3 were set on a crucible cradle 43a in the single crystal pulling apparatus, and fitted with a quartz crucible 42, and then filled with a crystal raw material. Next, the raw material for crystallization was heated to a high temperature to obtain a melt 47. The crucible support 43a used had a top surface of a crucible bottom and a diameter of 260 mm.

The amount of the raw material for crystallization was such that, when the molten liquid 47 was used, the liquid level was の of the depth of the quartz crucible 42. Then, the test for holding the single crystal 51 for the same time as the time required for pulling the single crystal without repeating the pulling of the single crystal 51 was repeated five times. Further, the temperature of the melt 47 is set to be about 50 ° C. higher than that at the time of single crystal pulling, and the surface of the single crystal pulling graphite crucible is made to be SiC.

(4) A single crystal pulling crucible to be manufactured,
Table 1 below shows the winding conditions of carbon fibers and the like, the results of shrinkage and delamination after carbonization, and the durability test.

[0050]

[Table 1]

As is clear from the results shown in Table 1 above, in Examples 1 to 6, the decrease in the inner diameter of the upper end of the single crystal pulling crucible was as small as 1.5 mm or less. Crucibles having almost the same shape as the initially set single crystal pulling crucible could be produced without occurrence of peeling. On the other hand, in the case of Comparative Example 1, the inner diameter was greatly reduced due to the large shrinkage of the inner peripheral portion in the radial direction in the carbonization step, and the crucible could not be suppressed in the inner peripheral portion. Peeling occurred between the fiber layers at the upper end of the crucible. In the case of Comparative Example 2, the deformation was larger, and peeling between fine fiber layers occurred at the upper end of the crucible in the carbonization step.

In the durability test, Examples 1 to 6
In the case of (1), there is no problem such as occurrence of peeling between the fiber layers and depletion. On the other hand, in the case of Comparative Example 3,
Due to the fitting part, peeling occurred at the fitting part. Also, wear was observed on the inner surface in contact with the quartz crucible.

As described above, in the method of manufacturing a crucible for pulling a single crystal according to the above-described embodiment, a mandrel for winding carbon fibers is used, and a portion corresponding to the inner peripheral portion of the crucible straight body is provided in a horizontal direction. On the other hand, after winding the continuous carbon fiber at an angle of -45 to + 45 °, or winding the continuous carbon fiber cloth, the outer peripheral portion and the portion corresponding to the bottom are not more than -45 ° or more than + 45 ° with respect to the horizontal direction. Since the continuous carbon fiber is wound at an angle and then carbonized, the shrinkage in the radial direction and the separation between fiber layers do not occur in the carbonizing step. Further, even when a durability test was carried out, no occurrence or depletion of peeling between the fiber layers was observed, and it was proved that the durability was excellent.

[Brief description of the drawings]

FIG. 1 shows a carbonization process for producing a graphite crucible for pulling a single crystal by a filament winding method.
It is the graph which showed the relationship between the winding angle ((theta)) of continuous carbon fiber, and the shrinkage amount in the radial direction.

FIG. 2 is a plan view schematically showing a single crystal pulling graphite crucible according to an embodiment of the present invention, and FIG. 2 (b) is a partially cutaway front view.

FIG. 3 is a plan view schematically showing a graphite crucible for pulling a single crystal according to another embodiment, and (b) is a partially cutaway front view.

FIG. 4 is a plan view schematically showing a graphite crucible for pulling a single crystal according to still another embodiment, and (b) is a partially cutaway front view.

FIG. 5 is a cross-sectional view schematically showing a conventional single crystal pulling apparatus used for the CZ method.

FIG. 6 is a cross-sectional view schematically showing a conventional graphite crucible for pulling a single crystal.

FIG. 7 is a front view schematically showing a state in which continuous carbon fibers are wound around a mandrel by a filament winding method.

[Explanation of symbols]

 10, 20, 30 Graphite crucible for pulling single crystal 11, 21, 31 Straight body 11a, 21a, 31a Inner circumference 11b, 21b, 31b Outer circumference 12, 22, 32 Bottom 13 Continuous carbon fiber 15 Continuous carbon fiber cloth

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-8-73292 (JP, A) JP-A-2-116696 (JP, A) JP-A-5-79598 (JP, A) JP-A-9-99 263482 (JP, A) JP-A-63-7174 (JP, A) JP-A-10-152391 (JP, A) JP-A-10-101471 (JP, A) Registered utility model 3012299 (JP, U) (58) ) Field surveyed (Int. Cl. ⁷ , DB name) C30B 1/00-35/00 C04B 35/52

Claims (4)

(57) [Claims] 1. A graphite crucible for pulling a single crystal comprising a carbon fiber reinforced carbon material, wherein continuous carbon fibers having an angle of −45 ° to + 45 ° with respect to a horizontal direction are arranged at least on an inner peripheral portion of a straight body portion, A graphite crucible for pulling a single crystal, wherein continuous carbon fibers having an angle of −45 ° or less or + 45 ° or more with respect to a horizontal direction are arranged in other portions. 2. A graphite crucible for pulling a single crystal comprising a carbon fiber reinforced carbon material, wherein a carbon fiber cloth is disposed at least on an inner peripheral portion of a straight body portion, and -45 ° or less with respect to a horizontal direction in other portions. Or a graphite crucible for pulling a single crystal, wherein continuous carbon fibers having an angle of + 45 ° or more are arranged. 3. A method of manufacturing a graphite crucible for pulling a single crystal by a filament winding method using carbon fibers, wherein at least a portion corresponding to an inner peripheral portion of a straight body portion of the crucible is horizontally oriented. After winding the continuous carbon fiber at an angle of -45 ° to + 45 ° with respect to the horizontal direction, the continuous carbon fiber is wound at an angle of −45 ° or less or + 45 ° or more with respect to the horizontal direction. A method for producing a graphite crucible for pulling a single crystal. 4. A method for manufacturing a graphite crucible for pulling a single crystal, comprising manufacturing a crucible for pulling a single crystal by winding the carbon fiber around a mold using carbon fiber, wherein at least a portion corresponding to an inner peripheral portion of a straight body portion. And a continuous carbon fiber wound around the other portion at an angle of -45 ° or less or + 45 ° or more with respect to the horizontal direction.