JP2000007485A - Single crystal production equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide equipment for the production of single crystal which facilitates crucible exchange operation after the completion of a single crystal production process and also is capable of generating a horizontal magnetic field in the crucible, changing the kind of the magnetic field generated in the crucible by easy operation and adjusting the magnetic field strength, while facilitating such crucible exchange operation. SOLUTION: This equipment is provided with a pair of coaxial opposite magnets 103 and 106 arranged oppositely to the upper and lower parts for a crucible 2 and a support member 109 for supporting these magnets 103 and 106 so that they can be disassembled. The pair of the coaxial opposite magnets 103 and 106 may be arranged oppositely to the horizontal direction. Further, a coil within the magnets 103, 106 may be a saddle-shaped coil in which the arc length of an actuate part can be adjusted and which is capable of generating either of a cusped magnetic field or a horizontal magnetic field.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single crystal manufacturing apparatus for pulling a single crystal from a raw material melt having conductivity by the Czochralski method, and particularly to a single crystal manufacturing apparatus for applying a DC magnetic field to the raw material melt in a crucible. The present invention relates to a crystal manufacturing apparatus.

[0002]

2. Description of the Related Art Conventionally, as a method for producing a semiconductor crystal from a raw material melt, the Czochralski method has been widely used. In this method, by applying an external magnetic field to the conductive raw material melt, the heat convection in the melt is suppressed,
Single crystals such as silicon (Si) and gallium arsenide (GaAs) can reduce contamination from the crucible material, suppress growth fringes and intrinsic defects generated during the single crystal growth process, and produce high quality single crystals. Has been confirmed.

An example of a single crystal manufacturing apparatus for pulling and manufacturing a single crystal by the Czochralski method is disclosed in Japanese Patent Publication No. 8-188.
No. 98 is known. FIG. 6 is a cross-sectional view showing a configuration of a single crystal manufacturing apparatus disclosed in Japanese Patent Publication No. 8-18898.

In FIG. 6, after a crucible 2 installed in a chamber 10 is filled with a single crystal material, for example, silicon, the silicon is heated and melted by a heater 11 to form a silicon melt 21. Is done. Crucible 2
The crucible drive unit 7 mechanically connected to the crucible 2
Is rotated to raise or lower the crucible 2 as necessary. At upper and lower positions of the surface 21a of the silicon melt 21, respectively, there are a substantially circular donut-shaped upper coil 4a and a lower coil 4b, and the positional relationship between the upper coil 4a and the lower coil 4b is maintained around the upper coil 4a and the lower coil 4b. There is a container 5 for supporting the electromagnetic force generated between the coils and the weight of the coil, and the upper coil 4a and the lower coil 4b
Are housed to form the magnet 3 integrally.

[0005] The magnet 3 surrounds the chamber 10. Further, a silicon melt 21 is placed on top of the crucible 2.
A crystal drive unit 8 is provided for producing a single crystal 9 by rotating while pulling. The single crystal manufacturing apparatus 1 is configured with the chamber 10, the magnet 3, the crucible drive unit 7, and the crystal drive unit 8 as main elements.

In the single crystal manufacturing apparatus 1, the silicon melt 21 grows below a seed crystal (not shown) suspended from the upper part, and the single crystal 9 is pulled up and manufactured. In this pulling step, a DC magnetic field is applied to the crucible by the magnet 3 arranged outside the single crystal manufacturing apparatus 1. When almost all the silicon melt 21 in the crucible 2 is pulled up, the production of the single crystal 9 is completed.

However, the crucible 2 used for manufacturing the single crystal 9 has a crack or the like due to the influence of heat generated in the single crystal manufacturing process and cannot be reused. Therefore, when the single crystal pulling step is completed, the magnet 3 is moved to the upper or lower part of the crystal driving unit 8, and a flange or the like (not shown) covering the chamber 10 from the upper part is disassembled to be disassembled.
Exchange. After replacing the crucible 2, the raw material is filled, and the next single crystal pulling operation is restarted.

By passing currents in the P direction in the figure, that is, in the directions opposite to each other, to the upper coil 4a and the lower coil 4b, equiaxial symmetry with respect to the central axis 2a of the crucible 2 as shown by a broken line 23 in FIG. A radial cusp magnetic field is formed.

[0009]

However, in order to disassemble the flange or the like of the chamber 10 when exchanging the crucible 2, it is necessary to have a heavy-weight drive mechanism (not shown) for moving the magnet 3 below the chamber 10. . Further, in order to move the magnet 3 above the chamber 10, it is necessary to carry out a large heavy object removing operation using a crane or the like.

Further, even if the direction of the current supplied to the upper coil 4a and the lower coil 4b is changed, the magnet 3 has only a cusp magnetic field or a vertical magnetic field which is equiaxially symmetric with respect to the central axis 2a of the crucible 2. Can be generated, and it is impossible to generate a horizontal magnetic field perpendicular to the central axis 2a of the crucible.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to solve the above-mentioned problems, and an object of the present invention is to provide a single crystal manufacturing apparatus which facilitates a crucible 2 exchange operation after a single crystal manufacturing step is completed. Things. It is another object of the present invention to provide a single crystal manufacturing apparatus capable of generating a horizontal magnetic field in a crucible while facilitating such an exchange operation. Further, it is another object of the present invention to provide a single crystal manufacturing apparatus capable of changing the type of a magnetic field generated in a crucible or adjusting the strength of the magnetic field by an easy operation while facilitating the exchange operation. .

[0012]

SUMMARY OF THE INVENTION A single crystal manufacturing apparatus according to the present invention is provided with a hollow cylindrical coil which is disposed vertically above and below a crucible and is coaxial with a central axis of the crucible, and a container for accommodating the coil. And a support member for supporting the magnets so that they can be disassembled from each other, so that a radial cusp magnetic field which is equiaxially symmetric with respect to the central axis of the crucible can be applied.

Further, the single crystal manufacturing apparatus according to the present invention
A pair of coaxial opposing magnets having a hollow cylindrical coil and a container for accommodating the coils, which are arranged coaxially with each other so as to face the central axis of the crucible in a horizontal direction, and support the magnets so that they can move in the horizontal direction. And a support member for applying a horizontal magnetic field to the crucible.

Further, a single crystal manufacturing apparatus according to the present invention comprises:
A pair of coaxial opposing magnets having a saddle-shaped coil and a container for accommodating the saddle-shaped coil, which are arranged coaxially with each other in a horizontal direction with respect to the central axis of the crucible, so that the magnets can be moved horizontally. It is characterized by the following.

Further, the single crystal manufacturing apparatus according to the present invention
The arc-shaped portion of the saddle-shaped coil is semicircular, and the vertical straight portion of the saddle-shaped coil is close to the vertical straight portion of another saddle-shaped coil,
It is characterized in that a radial cusp magnetic field can be applied which is equiaxially symmetric with respect to the central axis of the crucible.

Further, the apparatus for producing a single crystal according to the present invention
The saddle-shaped coil is characterized in that the arc-shaped portion is arcuate, and the vertical straight portion of the saddle-shaped coil is separated from the vertical straight portion of another saddle-shaped coil.

Further, the apparatus for producing a single crystal according to the present invention
The present invention is characterized in that a horizontal magnetic field can be applied to a crucible by making the directions of currents flowing through the vertical straight portions of the saddle coils facing each other the same.

Further, the apparatus for producing a single crystal according to the present invention
The saddle-shaped coil includes a mechanism for adjusting the length of the arc-shaped portion of the saddle-shaped coil.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a partial cross-sectional view showing a single crystal manufacturing apparatus 100 according to an embodiment of the present invention.

In the figure, components having the same reference numerals as those in FIG. 6 perform the same functions as those in FIG. After the crucible 2 installed inside the chamber 10 is filled with, for example, silicon, which is a single crystal raw material, silicon is heated and melted by a heater 11 which is a heating device installed around the crucible 2 to melt the silicon. A liquid 21 is formed. The crucible drive unit 7 mechanically connected to the crucible 2 rotates the crucible 2 and raises or lowers the crucible 2 as required.

Surface 2 of silicon melt 21 in crucible 2
An upper coil 104, which is a hollow cylindrical coil coaxial with the central axis 2a of the crucible 2, is located at an upper position with respect to 1a.
An upper magnet 103 having an upper container 105 for accommodating the upper coil 104 is provided. On the other hand, the lower coil 107, which is a hollow cylindrical coil coaxial with the central axis 2a of the crucible 2, and the lower coil housing the lower coil 107 are located at a lower position with respect to the surface 21a of the silicon melt 21 in the crucible 2. A lower magnet 106 having a container 108 is provided.

Upper magnet 103 and lower magnet 1
06, the upper coil 10 in these magnets
4 or a support member 109 having a U-shaped cross section for supporting and fixing the positional relationship between the upper magnet 103 and the lower magnet 106 by receiving a repulsive force generated between the magnets due to an electromagnetic force generated by a current flowing through the lower coil 107. Is provided. Therefore, the support member 109 constitutes a coaxial magnet in which the upper coil 104 and the lower coil 107 are disposed coaxially opposite to the center axis of the crucible 2. Support member 109
Are fastened to the upper magnet 103 and the lower magnet 106 by fastening members (not shown).
By removing this fastening member, the upper magnet 10
3 and the lower magnet 106 are disassembled from the support member 109.

A current is supplied to the upper coil 104 and the lower coil 107 in the directions indicated by arrows A in the drawing, that is, in the directions opposite to each other. A radial cusp magnetic field can be applied.

When the crucible 2 is replaced after the single crystal manufacturing process is completed, the upper magnet 103 and the lower magnet 1 are replaced.
06 is disassembled from the support member 109 by removing a fastening member (not shown). Therefore, the disassembled upper magnet 103 and lower magnet 106
Is less than half the weight of the conventional magnet 3, so that the upper magnet 103 and the lower magnet 106 can be easily moved, so that the crucible 2 can be easily replaced.

The support member 109 does not need to have a U-shaped cross section, and may be any structure that can support and fix the positional relationship between the upper magnet 103 and the lower magnet 106. Further, the upper coil 103 and the lower coil 106 may be either a normal conducting coil or a superconducting coil.

Embodiment 2 FIG. FIG. 2 is a partial sectional view showing a single crystal manufacturing apparatus 200 according to an embodiment of the present invention.
1, the arrangement and support structure of the magnet around the chamber 10 are different.

In FIG. 1, a first magnet 204 having a hollow cylindrical coil and a first container 205 accommodating the first coil 204 are coaxially opposed to each other in a horizontal direction with respect to a central axis 2a of the crucible 2. 203 and the second coil 207 and the second coil 2 which are hollow cylindrical coils
A second magnet 206 having a second container 208 accommodating 07 is provided.

Further, around the first magnet 203 and the second magnet 206, both are held and fixed in a coaxial positional relationship to support the support members 211 and 212 for supporting the first magnet 203 and the second magnet 206. Support members 213 and 214 are provided.
06. By removing this fastening member, the first magnet 203 and the second magnet 206
The support members 212, 212, 213, and 214 are disassembled and can be moved in a horizontal direction by using a movement drive mechanism (not shown).

A horizontal magnetic field as indicated by a broken line 223 can be applied to the crucible 2 by applying a current to the first coil 204 and the second coil 207 in the directions indicated by arrows B in FIG.

A roller is provided below the first magnet 203 and the second magnet 206, and the first magnet 203 and the second magnet 206 are provided along a rail provided on the surface on which the first magnet 203 and the second magnet 206 are provided. May be easily moved.

Embodiment 3 FIG. 3 is a partial sectional view showing a single crystal manufacturing apparatus 300 according to an embodiment of the present invention.
1, the arrangement and support structure of the magnet around the chamber 10 are different.

In the figure, a cross section is rectangular, and a pair of mutually adjacent semicircular arc-shaped portions 304a and vertical straight portions 3a.
A first magnet 303 having a saddle-shaped first coil 304 made of 04b and a first container 305 accommodating the saddle-shaped first coil 304 is provided. Also, the central axis 2 of the crucible 2
With respect to a, the position symmetrical to the saddle type first coil 304 is symmetrical to the saddle type first coil 304, the cross section is rectangular,
A second magnet 306 having a saddle-shaped second coil 307 including a pair of mutually adjacent semicircular arc-shaped portions 307a and a vertical straight portion 307b and a second container 308 for accommodating the saddle-shaped second coil 307 is provided. . The first magnet 303 and the second magnet 306 have a hollow and substantially semi-cylindrical shape that covers the saddle-shaped coil, and a pair of coaxially arranged coaxially opposed to the central axis 2a of the crucible 2 in the horizontal direction. It constitutes a coaxial opposed magnet and is fastened by a fastening member (not shown). By removing this fastening member, the first magnet 303 and the second magnet 306 are disassembled, and can be moved in the horizontal direction by using a movement drive mechanism (not shown).

The first saddle coil 304 and the second saddle coil 3
07, by flowing a current in the direction of the arrow indicated by C,
A radial cusp magnetic field can be applied coaxially and symmetrically with respect to the central axis 2a of the crucible 2 as shown by a broken line 323.
The vertical straight portion 304b of the saddle type first coil 304 and the saddle type second coil 304
Since the vertical linear portions 307b of the coil 307 are close to each other and have opposite current directions, the magnetic field generated in this portion is canceled.

Embodiment 4 FIG. 4 is a partial sectional view showing a single crystal manufacturing apparatus 400 according to an embodiment of the present invention.
FIG. 5 is a view as viewed from the X direction in FIG. The embodiment of the present invention is different from FIG. 3 in that the dimensions of the saddle-shaped coil can be adjusted.

In FIG. 4, the first saddle coil 404 is
It is configured by combining two vertical straight portions 414b and U-shaped coils 414 having arcuate portions 414a at both ends thereof. The U-shaped coil 414 has a comb-shaped portion 414 having a rectangular cross section and a plurality of protrusions at the tip of the arc-shaped portion 414a.
c is provided. As shown in FIG. 5, the comb teeth 414c of the two U-shaped coils 414 engage with each other to fit in the gap 41d therebetween, and the L dimension can be adjusted. By adjusting the L dimension, which is the length engaged with the comb teeth 414c, the arc length of the arcuate arc portion 404a of the first saddle coil 404 can be adjusted. The saddle-shaped second coil 407 is symmetrical to the saddle-shaped first coil 404 and is configured similarly to the saddle-shaped first coil 404. The vertical straight portion 414b of the saddle type first coil 404 and the vertical straight portion 4
17b are arranged apart from each other.

Further, similarly to FIG.
04 is a first container 405 for accommodating the first saddle coil 404
The first magnet 403 is accommodated in the
The coil 407 is accommodated in a second container 408 accommodating the saddle-shaped second coil 407 to form a second magnet 406. The first magnet 403 and the second magnet 406
Saddle-shaped first coil 404 and saddle-shaped second coil 407, respectively
A pair of coaxial opposed magnets which are coaxial with each other and are horizontally opposed to the center axis 2a of the crucible 2 and are fastened by fastening members (not shown). Have been. By removing the fastening member, the first magnet 403 and the second magnet 40
6 can be moved in the horizontal direction by using a movement drive mechanism (not shown).

When current flows in the saddle type first coil 404 and saddle type second coil 407 in the direction d in FIG.
A horizontal magnetic field can be applied in the same direction as in FIG.

The L dimension is adjusted, and the vertical straight portion 414b of the saddle type first coil 404 and the saddle type second coil 407 are adjusted.
When a current flows in the direction e in FIG. 4 when the vertical linear portion 417b is brought close as shown in FIG. 3, an equiaxially symmetric and radial cusp magnetic field coaxial with the central axis 2a of the crucible 2 as in FIG. Can be applied. At this time, the vertical linear portion 414b of the saddle type first coil 404 and the vertical linear portion 417b of the saddle type second coil 407 are close to each other and have opposite current directions. Is done.

Therefore, according to the embodiment of the present invention, a cusp magnetic field radially symmetric with respect to the central axis 2a of the crucible 2 or a horizontal magnetic field with respect to the crucible 2 can be easily generated according to the application. Further, the distribution of the magnetic field can be changed depending on the length of the L dimension.

[0040]

As is apparent from the above description, according to the present invention, the crucible is disposed so as to face up and down,
And a pair of coaxial opposed magnets having a hollow cylindrical coil coaxial with the central axis of the crucible and a container accommodating the coil, and a support member for supporting the magnet so that the magnet can be disassembled. The crucible replacement operation after completion can be facilitated. In addition, a drive mechanism for moving the magnet when replacing the crucible can be omitted.

Further, according to the present invention, a pair of coaxial opposed magnets having a hollow cylindrical coil and a container for accommodating the coils, which are arranged coaxially with each other in the horizontal direction with respect to the central axis of the crucible, And a support member for supporting each of the crucibles so as to be able to move in the horizontal direction, so that a horizontal magnetic field can be applied to the crucible while facilitating the work of replacing the crucible.

Further, according to the present invention, there is provided a pair of coaxial opposed magnets having a saddle-shaped coil and a container for accommodating the saddle-shaped coil, which are arranged coaxially with each other in the horizontal direction with respect to the central axis of the crucible, Since it can be moved in the horizontal direction, it is easy to replace the crucible.

Further, according to the present invention, the arc-shaped portion of the saddle coil is arcuate, and the vertical linear portions of the saddle coil are separated from the vertical linear portions of the other saddle coils. The horizontal magnetic field can be applied to the crucible by making the direction of the current flowing through the vertical straight portions of the saddle coils facing each other the same while facilitating the exchange work.

Further, according to the present invention, since the saddle-shaped coil is provided with a mechanism for adjusting the length of the arc-shaped portion of the saddle-shaped coil, a cusp magnetic field which is axially symmetric with respect to the central axis of the crucible, or A horizontal magnetic field can be easily generated for the crucible according to the application. Further, the distribution of the generated magnetic field can be changed.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a single crystal manufacturing apparatus according to a first embodiment of the present invention.

FIG. 2 is a partial sectional view of a single crystal manufacturing apparatus according to a second embodiment of the present invention.

FIG. 3 is a partial sectional view of a single crystal manufacturing apparatus according to a third embodiment of the present invention.

FIG. 4 is a partial sectional view of a single crystal manufacturing apparatus according to a fourth embodiment of the present invention.

FIG. 5 is a view as seen from an arrow X in FIG. 4;

FIG. 6 is a partial cross-sectional view of a conventional single crystal manufacturing apparatus.

[Explanation of symbols]

100, 200, 300, 400 Single crystal production equipment, 2
Crucible, 2a center axis, 103 upper magnet, 1
04 upper coil, 105 upper container, 106 lower coil,
106 lower magnet, 107 lower coil, 108
Lower container, 109 support member, 203, 303, 403
1st magnet, 204 1st coil, 205, 30
5, 405 first container, 206, 306, 406 second
Magnet, 207 second coil, 208, 308, 4
08 second container, 211, 212, 213, 214 support member, 304, 404 saddle type first coil, 304
a, 307a, 404a, 407a Arc-shaped part, 304
b, 307b, 414b, 417b Vertical straight part, 30
7,407 Second saddle type coil, 414 U-shaped coil.

Claims (7)

[Claims] 1. A single crystal manufacturing apparatus for applying a direct current magnetic field to a raw material melt accommodated in a crucible to pull up and manufacture a single crystal by a Czochralski method, wherein the single crystal manufacturing apparatus is disposed vertically opposite to the crucible, and A pair of coaxial opposed magnets having a hollow cylindrical coil coaxial with the center axis of the crucible and a container accommodating the coil; and a support member for supporting the magnets so that they can be disassembled. A single crystal manufacturing apparatus characterized in that a radial cusp magnetic field that is equiaxially symmetric and radial can be applied to the apparatus. 2. A single crystal manufacturing apparatus for applying a direct current magnetic field to a raw material melt contained in a crucible to pull up and manufacture a single crystal by a Czochralski method, wherein the single crystal is horizontally opposed to a central axis of the crucible. A pair of coaxial opposing magnets having a hollow cylindrical coil and a container for accommodating the coil, and a support member for supporting the magnets so as to be able to move in the horizontal direction. An apparatus for producing a single crystal, which can apply a magnetic field. 3. A single crystal manufacturing apparatus for applying a direct current magnetic field to a raw material melt contained in a crucible and pulling and manufacturing a single crystal by a Czochralski method, wherein the single crystal is horizontally opposed to a central axis of the crucible. An apparatus for producing a single crystal, comprising: a pair of coaxial opposed magnets each having a saddle-shaped coil arranged coaxially and a container accommodating the saddle-shaped coil, wherein the magnet can be moved in a horizontal direction. 4. An arc-shaped portion of the saddle-shaped coil is semicircular, and vertical straight portions of the saddle-shaped coil are close to each other and perpendicular to the center of the crucible. 4. The single crystal manufacturing apparatus according to claim 3, wherein a radial cusp magnetic field that is equiaxially symmetric can be applied. 5. The simple structure according to claim 3, wherein the arc-shaped portion of the saddle-shaped coil is arcuate, and the saddle-shaped coil is separated from the vertical straight portions of the other saddle-shaped coils. Crystal manufacturing equipment. 6. The single crystal manufacturing apparatus according to claim 5, wherein a horizontal magnetic field can be applied to the crucible by making the directions of currents flowing through the vertical straight portions of the saddle coils opposed to each other the same. 7. The single crystal manufacturing apparatus according to claim 3, wherein said saddle coil includes a mechanism for adjusting a length of an arc-shaped portion of said saddle coil.