JP3838470B2 - Apparatus for introducing high-frequency current into high-frequency induction heating coil for FZ and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a high-frequency current introducing device for a high-frequency induction heating coil for FZ used in a floating zone melting method (hereinafter referred to as FZ method) and a manufacturing method thereof. The present invention relates to a current introduction device having a coaxial structure for introducing a high-frequency current into a heating coil and a method for producing the same in a semiconductor single crystal production device that performs single crystal growth while melting.
[0002]
[Prior art]
An apparatus for manufacturing a semiconductor single crystal by the FZ method is for performing single crystal growth while sequentially melting a raw material polycrystal using a heating coil surrounded by an outer periphery, and for supplying a heating current to the heating coil. A current introduction device is used.
[0003]
2 and 3 show a conventional current introducing device of this type. The current introduction device A includes an inner tube 1 and an outer tube 2 having a coaxial structure.
[0004]
The inner tube 1 has a semicircular inner tube coil mounting portion 3 protruding from substantially half of the tip surface. A pipe attachment hole 4 and a coil attachment hole 5 are formed in the inner tube coil attachment portion 3, and a pipe attachment hole 7 is formed in the remaining half of the pipe attachment portion 6. A cooling pipe 9 is attached between the high-frequency introduction part 8 at the rear part of the inner pipe 1 and the pipe attachment hole 4. The rear end of the other cooling pipe 10 is attached to the high-frequency introduction portion 8 via an insulating spacer 11, and the tip is attached to a joint 13 inserted into the pipe attachment hole 7 via an insulating spacer 12. It has been.
[0005]
The outer tube 2 is formed with an opening 15 into which the inner tube coil mounting portion 3 is fitted in substantially half of the tip, and a pipe mounting hole 17 and a coil mounting hole 18 are formed in the remaining outer tube coil mounting portion 16. Is formed. The joint 13 is attached to the pipe attachment hole 17. A flange 20 is formed at the rear end of the outer tube 2.
[0006]
As shown in FIG. 2, the inner tube 1 is inserted into the outer tube 2, and the inner tube coil attachment portion 3 is fitted into the opening 15. Between the inner tube 1 and the outer tube 2, an insulating spacer 21 is mounted at the rear, and between the inner tube coil mounting portion 3 and the opening 15, and between the pipe mounting portion 6 and the outer tube coil mounting portion 16. An insulating spacer 22 is interposed between the inner surface and the inner surface. A sealing material 23 is attached to the rear end of the insulating spacer 22.
[0007]
It is important that the end surface of the inner tube coil mounting portion 3 and the end surface of the outer tube coil mounting portion 16 are exactly on the same plane. If the end faces of the mounting portions 3 and 16 are not coincident, the heating coil 32 mounted here is deformed, adversely affects the quality of the single crystal silicon, and operation troubles frequently occur.
[0008]
Therefore, conventionally, after the inner tube coil mounting portion 3 and the outer tube coil mounting portion 16 are finished by end face cutting before the inner tube 1 and the outer tube 2 are combined, the end surfaces are combined by combining them. Try to match. That is, after finishing the end face (hole machining and cutting) of the outer tube coil mounting portion 16 of the outer tube 2, the outer tube coil mounting portion 16 is welded 24 to the main body of the outer tube 2, and the inner tube 1 (inner tube 1 A similar end face finish is performed on the coil mounting portion 3) and is inserted into the outer tube 2 and combined.
[0009]
[Problems to be solved by the invention]
In the manufacture of the conventional current introduction device A, the end faces are separately finished before the inner pipe 1 and the outer pipe 2 are combined as described above. There was a problem that it was likely to occur.
[0010]
That is, processing errors in end face finishing of the inner tube 1 and the outer tube 2 occur, errors occur due to the combination error of the outer tube coil mounting portion 16 and the main body portion of the outer tube 2 and distortion of the welded portion 24, and the inner tube 1. In many cases, end face mismatches have already occurred when assembly is completed due to factors such as a combination error of the outer tube 2.
[0011]
4A and 4B are diagrams showing a state in which the inner tube coil mounting portion 3 is inclined, wherein FIG. 4B is a state in which the outer tube coil mounting portion 16 is inclined with respect to the surface at an angle θ1, and FIG. The part 16 is shown tilted at an angle θ2 with respect to the surface.
[0012]
Further, even if there is no mismatch of the end faces at the time of assembly, the mismatch of the end faces may occur due to the displacement of the inner tube 1 in the axial direction and the radial direction due to changes in pressure in the furnace and changes over time.
[0013]
For the reasons described above, if the end face finish of the inner tube 1 is performed after the inner tube 1 and the outer tube 2 are combined, it is possible to correct both inconsistencies due to assembly and later-occurring inconsistencies. It is. However, when this method is performed, a force due to end face finishing (drilling and end face cutting) is applied to the inner tube 1, and the inner tube 1 is displaced because there is no means for supporting this force conventionally. Therefore, conventionally, it is necessary to finish the end face before the inner tube 1 and the outer tube 2 are combined.
[0014]
The present invention has been made in view of the disadvantages of the prior art, and by performing end face finishing of the coil mounting portion after combining the inner pipe and the outer pipe, the deformation of the heating coil due to end face mismatch is prevented. An object of the present invention is to provide an apparatus for introducing a high-frequency current into a high-frequency induction heating coil for FZ that enables stable operation of a semiconductor single crystal manufacturing apparatus.
[0015]
[Means for Solving the Problems]
In order to solve such a problem, the invention described in claim 1 includes an inner tube and an outer tube having a coaxial structure, and the inner tube coil mounting portion and the outer tube coil mounting portion on the distal end surface of the inner tube and the outer tube are provided. In the high frequency current introducing device to the high frequency induction heating coil for FZ to which the high frequency induction heating coil for FZ is attached,
A plurality of bolts screwed into the outer tube hold the outer periphery of the inner tube, while the inner tube coil mounting portion and the outer tube coil mounting portion located on the front end surface of the inner tube and the outer tube are finished with end faces. It is characterized by that.
[0016]
A plurality of bolt screwing positions of the outer tube are in the vicinity of a flange provided on the outer tube .
[0017]
According to a third aspect of the present invention, a substantially semicircular inner tube coil attachment portion and a pipe attachment portion are formed at the tip in an outer tube having a substantially semicircular diameter opening and an outer tube coil attachment portion formed at the tip. In the method of manufacturing a high-frequency current introducing device for a high-frequency induction heating coil for FZ in which the inner tube is inserted and the inner tube coil mounting portion is fitted and combined with the opening, the inner tube and the outer The end face finishing of the inner tube coil mounting portion and the outer tube coil mounting portion is performed after the combination of the tubes.
[0018]
The end face finishing is performed in a state where the inner tube is held by a plurality of bolts screwed into the outer tube, and the rear surfaces of the inner tube and the outer tube are pressed by a fixing plate.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be exemplarily described below with reference to the drawings. However, the dimensions, materials, shapes, relative positions, and the like of the structural parts described in this embodiment are not intended to limit the scope of the present invention only to specific descriptions unless otherwise specified. It is just an example. In addition, the same member or the same function as FIG. 2 thru | or FIG. 4 is shown with the same code | symbol.
[0020]
FIG. 1 shows a current introducing device of the present invention. In order to manufacture this device, first, the parts of the outer tube coil mounting portion 16 of the outer tube 2 are processed (the end face is not cut), and then the outer tube coil mounting portion 16 is welded to the body portion of the outer tube 2. Then, the inner tube 1 is combined with the outer tube 2.
[0021]
After the combination of the inner pipes 1 is completed, the end faces of the inner pipe 1 and the outer pipe 2 are subjected to end face finishing such as drilling and end face cutting. At this time, the following means are provided so that the inner tube 1 is not displaced.
[0022]
That is, in FIG. 1, the current introduction device A of the present invention includes a metal outer tube 2 as well as a metal inner tube 1. Further, the distal end portion of the inner tube 1 is welded to the end block 101, and the inner tube coil mounting portion 3 and the pipe mounting portion 6 are formed on the end block 101.
[0023]
In the present invention, the inner tube 1 is supported by a bolt 30 made of an insulator such as silicon nitride or alumina screwed into the outer tube 2. That is, three bolts 30 arranged at equal intervals are screwed into the outer periphery of the outer tube 2, preferably the side wall of the outer tube coil mounting portion 16, and the distal end portion of the inner tube 1, preferably the end, at the distal end of the bolt 30. The outer periphery of the block 101 is tightened. Since the position of the inner tube 1 is kept so as not to move by the bolt 30, the inner tube 1 will not be displaced even if end face finishing is performed.
[0024]
When finishing the end face, the fixing plate 32 as shown in FIG. 1 is held in close contact with the high-frequency introduction portion 8 of the inner tube 1 and the flange 20 portion of the outer tube 2 from the rear surface, so that the inner tube 1 and The outer tube 2 is held more reliably. For example, a copper plate or the like is used as the fixing plate 32, but the material is not particularly limited as long as the end plate is finished so long as the inner tube 1 and the outer tube 2 can be sufficiently held.
[0025]
It is most preferable in terms of strength that the bolt 30 is attached to a portion having higher rigidity than other portions such as the outer tube coil mounting portion 16 at the end of the outer tube 2 and the end block 101 at the end of the inner tube 1. . In addition, the use of three bolts 30 is preferable because the roundness of the inner tube 1 relative to the outer tube 2 can be adjusted. However, the purpose of maintaining the position of the inner tube 1 can be achieved with two or arbitrary plural bolts.
[0026]
【The invention's effect】
As described above in detail, according to the current introduction device of the present invention, since the inner tube is held by a plurality of bolts screwed into the outer tube, the inner tube and the outer tube are accurately held in a coaxial perfect circle. Because the inner tube can be prevented from being displaced due to changes in furnace pressure and changes over time, the heating coil can be prevented from being deformed, and the quality of the single crystal silicon can be improved. It becomes possible.
[0027]
Further, according to the method for manufacturing a current introduction device of the present invention, the end surfaces of the inner tube coil mounting portion and the outer tube coil mounting portion are finished after the combination of the inner tube and the outer tube. Even if there is a mismatch between the end faces due to the machining error, the combination error of the two, the error due to welding distortion, etc., it can be corrected later, so that a highly accurate current introduction device can be obtained.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view showing an embodiment of a current introduction device of the present invention.
FIG. 2 is a vertical side view of a conventional current introduction device.
FIG. 3 is an exploded perspective view of a conventional current introduction device.
4A and 4B are diagrams showing a mismatch of conventional coil mounting portions, where FIG. 4A is a front view, FIG. 4B is a left side view of FIG. 4A, and FIG. 4C is a top view of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Inner tube 2 Outer tube 3 Inner tube coil attaching part 6 Pipe attaching part 15 Opening part 16 Outer tube coil attaching part 30 Bolt 32 Fixing plate

Claims (5)

A high-frequency induction heating for FZ comprising an inner tube and an outer tube having a coaxial structure, and a high-frequency induction heating coil for FZ being attached to an inner tube coil mounting portion and an outer tube coil mounting portion on the tip surfaces of the inner tube and the outer tube. In the high-frequency current introducing device to the coil,
A plurality of bolts screwed into the outer tube hold the outer periphery of the inner tube, while the inner tube coil mounting portion and the outer tube coil mounting portion located on the front end surface of the inner tube and the outer tube are finished with end faces. A high-frequency current introducing device for a high-frequency induction heating coil for FZ. The high frequency current introducing device to the high frequency induction heating coil for FZ according to claim 1, wherein a plurality of bolt screwing positions of the outer tube are in the vicinity of a flange provided on the outer tube . An inner tube having a substantially semicircular inner tube coil mounting portion and a pipe mounting portion formed at the tip is inserted into the outer tube having a substantially semicircular diameter opening and an outer tube coil mounting portion formed at the tip, In the manufacturing method of the high-frequency current introducing device to the high-frequency induction heating coil for FZ that is adapted to fit and combine the inner tube coil mounting portion with the opening,
A method of manufacturing a high-frequency current introducing device for a high-frequency induction heating coil for FZ, wherein end face finishing of the inner tube coil mounting portion and the outer tube coil mounting portion is performed after the combination of the inner tube and the outer tube.   4. The method of manufacturing a high-frequency current introducing device for a high-frequency induction heating coil for FZ according to claim 3, wherein the end face finishing is performed in a state where the inner tube is held by a plurality of bolts screwed into the outer tube. .   5. The method of manufacturing a high-frequency current introducing device for a high-frequency induction heating coil for FZ according to claim 3 or 4, wherein the end face finishing is performed in a state where the rear surfaces of the inner tube and the outer tube are pressed by a fixing plate.

Images