JP2019167254A - Polycrystal raw material holding tool of fz furnace - Google Patents

Abstract

To provide the polycrystal raw material holding tool of a FZ furnace, capable of preventing a thermal effect even when heating a silicon polycrystal raw material in the manufacture of a silicon single crystal by a FZ method.SOLUTION: A polycrystal raw material holding tool 9 in a FZ (Floating Zone) furnace, holding a silicon polycrystal raw material 2 in the FZ furnace comprises: a support shaft 11 for supporting the load of the silicon polycrystal raw material 2; a chuck part 15 inserting a plurality of locking parts 16 for locking the silicon polycrystal raw material 2; a horizontal positioning part 12 for positioning the plurality of locking parts 16 in the horizontal direction; and a shield part 17 arranged to provide a space between the plurality of locking parts 16 and the horizontal positioning part 12 and for shielding radiant heat from the silicon polycrystal raw material 2.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a polycrystalline raw material gripping tool for an FZ (Floating Zone) furnace.

  Conventionally, when a silicon single crystal is manufactured by the FZ (Floating Zone) method, a silicon polycrystalline raw material is held by a silicon polycrystalline raw material gripping tool, and a seed crystal holder and a high-frequency induction heating coil disposed in the lower part of the chamber are provided. A silicon single crystal ingot is manufactured by melting a polycrystalline raw material of silicon. Here, when the silicon polycrystalline material is melted by the high-frequency induction heating coil, the silicon polycrystalline material is melted with the polycrystalline material gripping tool held.

For example, Patent Document 1 includes a cylindrical internal adapter that opens downward and an external adapter that is provided on the outer surface thereof, and a pressing member that presses and holds the outer peripheral wall of the silicon polycrystalline material on the outer peripheral wall of the external adapter. A polycrystalline raw material holder provided with an arm is disclosed.
Further, Patent Document 2 includes a cylindrical adapter that opens downward, and is provided with an eccentric piece that gradually increases in rotational radius when rotated downward at the lower end of the adapter. A polycrystalline raw material holder for holding a silicon polycrystalline raw material by increasing the radius of rotation is disclosed.

Japanese Patent Laid-Open No. 5-148071 JP-A-5-246792

The techniques described in Patent Document 1 and Patent Document 2 have a structure in which a holding arm made of stainless steel or an eccentric piece is held in contact with the outer peripheral side surface of the polycrystalline silicon. Since the coefficient of thermal expansion of silicon polycrystalline material is higher than that of stainless steel, if the silicon polycrystalline material becomes shorter and the influence of radiant heat on the holder becomes larger, the gripping force due to the displacement of the eccentric piece or arm part There is a problem that galling or the like occurs due to seizure of the arm portion, seizure of the pressing bolt of the arm portion or the holding screw of the eccentric piece.
Moreover, since the cylindrical opening exists in the center, there is also a problem that the upper rotating shaft to be coupled is affected by heat.
Due to the above problems, there has been a problem that the shift (center runout) of the rotation axis center increases as the crystal growth proceeds.

  An object of the present invention is to provide a polycrystalline raw material gripping tool for an FZ furnace that is less susceptible to thermal influence even when the silicon polycrystalline raw material is heated in the production of a silicon single crystal by the FZ method, and in which the increase in core runout accompanying crystal growth is small. It is to provide.

  A polycrystalline raw material gripping tool for an FZ furnace according to the present invention is a polycrystalline raw material gripping tool for an FZ furnace for gripping a silicon polycrystalline raw material for an FZ (Floating Zone) furnace, and supports the load of the silicon polycrystalline raw material. A shaft, a chuck portion through which a plurality of locking portions for locking the silicon polycrystalline raw material are inserted, a horizontal position adjusting portion for adjusting the position of the plurality of locking portions in the horizontal direction, and the plurality of locking portions And a shielding part that is arranged with a gap between the horizontal position adjusting parts and shields radiant heat from the silicon polycrystal raw material.

  According to the present invention, the polycrystalline raw material gripping tool is provided with the shielding part, so that the silicon polycrystalline raw material is heated by the high frequency induction heating coil, and the chuck part is displaced due to thermal distortion caused by the generated radiant heat. Accordingly, it is possible to prevent the grip bolt from being displaced following the movement. Furthermore, it can suppress that the influence of the heat | fever by the heating of a silicon polycrystal raw material transfers to a horizontal position adjustment part, and can also suppress that the adjustment state of a horizontal position adjustment part changes.

In the present invention, the horizontal position adjusting portion is provided so as to surround the support shaft, and is screwed into each of the position adjusting portion main body in which a plurality of female screw holes are formed around the support shaft and the female screw holes. Preferably, the front end includes a plurality of bolts abutting against the support shaft, and the female screw holes and the bolts facing each other have different screw pitches.
According to the present invention, by changing the screwing amount of the bolt to be screwed into the female screw hole of the position adjusting unit main body, the pushing amount to the support shaft is changed, and the silicon polycrystalline material gripping position with respect to the support shaft is changed. Can be changed. In addition, by changing the female screw holes facing each other and the screw pitch of the bolts, it is possible to finely adjust the pushing amount of the bolts, so that the holding position of the silicon polycrystalline material relative to the support shaft can be adjusted with high accuracy. it can.

In the present invention, the plurality of female screw holes are formed in a pair in a direction orthogonal to each other, and the pair of female screw holes orthogonal to each other has one screw pitch smaller than the other screw pitch, and the pair of female screw holes It is preferable to adjust the screwing position of the bolt to be screwed onto the screw.
According to the present invention, since the pair of female screw holes are formed in a direction orthogonal to each other, by adjusting the screwing position of the bolts inserted into the respective female screw holes, the shaft of the silicon polycrystalline raw material can be adjusted. It can be adjusted to the center of the FZ furnace. In particular, since one screw pitch is smaller than the other screw pitch, it is possible to adjust the approximate position with a large pitch bolt and finely adjust with a small pitch bolt. Can be done. Therefore, by positioning the silicon polycrystal raw material with high accuracy, it is possible to prevent the silicon polycrystal from drawing a circular orbit having a predetermined diameter during the growth of the silicon single crystal.

In the present invention, the chuck portion includes an upper plate and a lower plate, and each of the upper plate and the lower plate is formed with a plurality of long holes from the outer periphery toward the radial center, and the plurality of long holes are interposed therebetween. It is preferable that the plurality of locking portions are inserted.
According to the present invention, since the locking portion is inserted into each of the long hole of the upper plate and the long hole of the lower plate, by rotating the upper plate and the lower plate relatively, the radial position of the locking portion and The circumferential position can be changed.

In this invention, it is preferable that the said heat shield part is comprised from the plate-shaped body made from stainless steel of thickness 0.8mm or more.
According to the present invention, the gap between the position adjusting portion main body and the locking portion can be reduced by forming the shielding portion from a stainless steel plate having a thickness of 0.8 mm or more. Therefore, a heat shielding effect can be ensured in a narrow gap, and deformation of the horizontal position adjustment unit can be suppressed.

The schematic diagram which shows the structure of the FZ furnace which concerns on embodiment of this invention. The top view and side view which show the structure of the polycrystalline raw material holding | gripping tool in the said embodiment. The top view and sectional drawing which show the structure of the polycrystalline raw material holding | gripping tool in the said embodiment. The top view which shows the structure of the heat shield in the said embodiment. The top view and sectional drawing which show the structure of the horizontal position adjustment part in the said embodiment. The side view which shows the structure of the polycrystalline raw material holding | gripping tool in a comparative example. The graph which shows the measurement result of a comparative example. The graph which shows the measurement result of an Example.

[1] Overall Configuration of FZ Furnace 1 FIG. 1 shows a schematic diagram of an FZ furnace 1 according to an embodiment of the present invention. The FZ furnace 1 is an apparatus for growing a silicon single crystal 3 from a silicon polycrystalline raw material 2 by an FZ (Floating Zone) method. The FZ furnace 1 includes a crystal holder 4, a high frequency induction heating coil 5, a heat insulating cylinder 6, a product single crystal weight holder 8, and a polycrystalline raw material gripper 9.

The crystal holder 4 is a member that holds the tip portion of the silicon single crystal 3. A seed crystal is fixed to the upper part of the crystal holder 4, and is pulled downward as the silicon single crystal 3 is grown. The product single crystal weight holder 8 contacts the shoulder of the silicon single crystal 3 and holds the weight of the silicon single crystal 3.
As will be described in detail later, the polycrystalline material gripping tool 9 chucks the upper end of the silicon polycrystalline material 2.

The high-frequency induction heating coil 5 is composed of a ring-like body and is not shown in the figure, but is connected to a high-frequency power source and melts the silicon polycrystalline raw material 2 by high-frequency induction heating to form a silicon melting zone 3A.
The heat insulating cylinder 6 is composed of a ring-shaped body that surrounds the grown silicon single crystal 3. The heat insulating cylinder 6 controls the temperature of the silicon single crystal 3 in the process of solidifying the melting zone 3A.

In such an FZ furnace 1, the upper end of the silicon polycrystalline raw material 2 is held by the polycrystalline raw material gripping tool 9, and the lower end of the silicon polycrystalline raw material 2 is melted by the high-frequency induction heating coil 5 fixed in the furnace. The The seed crystal fixed to the crystal holder 4 is brought into contact with the silicon melting zone 3A, and the melt is solidified while increasing the diameter to the desired diameter while pulling down to reach the diameter of the diameter. After that, the melt is solidified so as to maintain the diameter of the straight cylinder, and the silicon single crystal 3 is manufactured. At this time, by simultaneously moving the silicon polycrystalline raw material 2 while rotating it, the lower end of the silicon polycrystalline raw material 2 is continuously melted, and an amount of melt necessary for single crystallization is supplied.
When the crystals have grown to some extent, they are held by the product single crystal weight holder 8.

[2] Structure of polycrystalline raw material gripping tool 9 FIGS. 2 and 3 show the structure of the polycrystalline raw material gripping tool 9. FIG. 2A is a plan view seen from above a horizontal position adjusting unit 12 described later, and FIG. 2B is a side view. FIG. 3A is a plan view seen from above a chuck portion 15 described later, and FIG. 3B is a cross-sectional view.
The polycrystalline material gripping tool 9 is an apparatus for gripping the silicon polycrystalline material 2. As shown in FIGS. 2 (A) and 2 (B), the polycrystalline raw material gripping tool 9 includes an upper shaft 10, a support shaft 11, a horizontal position adjusting portion 12, a hanging portion 13, an inclination adjusting bolt 14, and a chuck portion 15. , A holding bolt 16 and a heat shield plate 17 are provided.

Upper shaft 10 is connected to an elevating mechanism and a rotating mechanism (not shown), and moves up and down and rotates silicon polycrystalline raw material 2 in the chamber.
The support shaft 11 is connected to the center of the upper shaft 10, a horizontal position adjusting unit 12 is provided around the support shaft 11, and a suspended portion 13 is connected to the lower end of the support shaft 11, and the silicon polycrystalline raw material 2 loads are supported.
As will be described in detail later, the horizontal position adjusting unit 12 moves the support shaft 11 in the horizontal direction, and adjusts the center position in the radial direction of the gripped silicon polycrystalline raw material 2 to the axis center of the upper shaft 10.

The hanging portion 13 is integrally provided at the lower end of the horizontal position adjusting portion 12 and is made of a circular plate-like body made of stainless steel, particularly SUS304. A suspension bar 13A is rotatably attached to the center of the suspension 13.
Although not shown, three female screw holes are formed around the support shaft 11 at a pitch of 120 ° near the outer periphery of the suspension 13.
The inclination adjusting bolt 14 is screwed into each female screw hole of the hanging portion 13, and the tip of the inclination adjusting bolt 14 comes into contact with the upper surface of the chuck portion 15. And the inclination of the chuck | zipper part 15 is changed by changing the protrusion amount of each inclination adjustment volt | bolt 14, and the hanging attitude | position of the silicon polycrystalline raw material 2 is adjusted.

As shown in FIGS. 3 (A) and 3 (B), the chuck portion 15 is made of a circular plate-like body made of stainless steel, particularly SUS304, and a silicon polycrystal is formed at the center of the disc of the chuck portion 15. Apart from the rotation mechanism of the raw material 2, the suspension bar 13A is rotatably connected with a degree of freedom in the horizontal direction.
The chuck portion 15 is composed of two layers in which an upper plate 15A and a lower plate 15B are stacked. In the upper plate 15A, five long holes 151 from the outer periphery toward the radial center are formed around the suspension bar 13A. In the lower plate 15B, five elongated holes 152 formed in a spiral shape from the outer periphery to the inner side of the lower plate 15B are formed around the suspension bar 13A.

The holding bolt 16 as the locking portion is made of a material made of molybdenum or stainless steel, particularly SUS304, and holds the silicon polycrystalline raw material 2. The holding bolt 16 includes a bolt 161, a positioning nut 162, a holding nut 163, a heat shield plate support nut 164, and a raw material holding plate 165. The presser nut 163, the heat shield plate support nut 164, and the raw material holding plate 165 may be integrated.
In the present embodiment, the bolts 161 are inserted through five locations around the support shaft at positions where the elongated holes 151 of the upper plate 15A and the elongated holes 152 of the lower plate 15B overlap. By rotating the upper plate 15A and the lower plate 15B relatively around the suspension bar 13A, the radial position and the circumferential position of the bolt 161 are changed.

The positioning nut 162 is screwed onto the upper end of the bolt 161. When the radial position and the circumferential position of the bolt 161 are determined, the positioning nut 162 is tightened with the chuck portion 15 supported by the lower holding nut 163. Thus, the gripping position of the gripping bolt 16 is determined.
The heat shield plate support nut 164 is screwed into the lower portion of the presser nut 163 and supports the heat shield plate 17 in a state of being separated from the chuck portion 15.

  The raw material holding plate 165 is a stainless steel circular plate provided at the lower end of the bolt 161. The raw material holding plate 165 is a circular plate-like body having a diameter larger than the diameter of the bolt 161. By inserting the edge of the raw material holding plate 165 into the groove 2A formed at the upper end of the silicon polycrystalline raw material 2, the silicon polycrystalline raw material 2 is locked to the polycrystalline raw material gripping tool 9.

[3] Structure of heat shield plate 17 FIG. 4 shows a heat shield plate 17 as a heat shield portion of the present embodiment.
The heat shield plate 17 is made of a circular plate-like body made of stainless steel, particularly SUS304, and has a plate thickness of 0.8 mm or more. The heat shield plate 17 is formed with five slits 171 from the outer peripheral edge toward the center, and the bolt 161 of the grip bolt 16 is inserted into each slit 171. A heat shield plate support nut 164 that is screwed to the bolt 161 is in contact with the heat shield plate 17, and the heat shield plate 17 is supported in a state of being separated from the chuck portion 15.

  The reason why the SUS304 disk-shaped body having a thickness of 0.8 mm or more is used as the heat shield plate 17 is that the tensile strength tends to decrease from about 400 ° C. in the physical properties of the material of SUS304. This is because of this. Therefore, if it is shielded by the heat shield plate 17, the radiant heat due to the heating of the silicon polycrystalline raw material 2 is blocked, and the propagation of heat due to the radiant heat to the upper chuck portion 15, the hanging portion 13 and the horizontal position adjusting portion 12 is prevented. Further, the chuck portion 15, the suspended portion 13, and the horizontal position adjusting portion 12 can be prevented from being deformed by heat. If the thickness is 0.8 mm or more, a shielding effect is expected, and 0.9 to 1.1 mm is preferable. If it is thicker than 1.2 mm, an increase in weight and deformation due to thermal distortion are related to the displacement of the grip bolt 16 and consequently affect the runout of the raw material, which is not preferable.

[4] Structure of Horizontal Position Adjustment Unit 12 FIG. 5 shows the horizontal position adjustment unit 12 constituting the polycrystalline raw material gripping tool 9. FIG. 5A is a plan view seen from above the horizontal position adjustment unit 12, and FIG. 5B is a cross-sectional view of the horizontal position adjustment unit 12.
As shown in FIG. 5, the horizontal position adjustment unit 12 includes a position adjustment unit main body 121, bolts 125 and 126, and a suspension rod support unit 127.
The position adjustment unit main body 121 is formed of a stainless steel cylindrical body whose upper surface is provided so as to surround the support shaft 11. A hole 122 into which the support shaft 11 is inserted is formed on the upper surface of the position adjustment unit main body 121. The hole 122 is formed larger than the diameter of the support shaft 11. Depending on where in the hole 122 the support shaft 11 is inserted, the horizontal position of the horizontal position adjusting unit 12 with respect to the support shaft 11 is changed.

Female screw holes 123 and 124 are formed on the side surface of the position adjustment unit main body 121. The female screw holes 123 and 124 are formed in the left-right direction in FIG. 5A (tentatively referred to as the X-axis direction) and in the vertical direction in FIG. 5A (tentatively referred to as the Y-axis direction). That is, the female screw holes 123 and 124 are disposed to face each other, and the combination of the two sets of female screw holes 123 and 124 is formed in a direction perpendicular to the X-axis direction and the Y-axis direction.
Further, the female screw hole 123 and the female screw hole 124 arranged to face each other have different screw pitches. Specifically, the female screw hole 123 is an M8 screw conforming to the JIS B 0205 standard, and is an M6 screw conforming to the female screw hole 124 same standard.

The bolt 125 is screwed into the female screw hole 123, and the bolt 126 is screwed into the female screw hole 124. That is, the M8 bolt 125 is screwed into the female screw hole 123, and the M6 bolt 126 is screwed into the female screw hole 124.
The front ends of the bolts 125 and 126 are in contact with the support shaft 11 and the horizontal positions of the horizontal position adjusting unit 12 are changed by changing the screwing positions of the bolts 125 and 126 facing each other. The horizontal position of the support part 127 is changed. Specifically, the amount of feed in the horizontal direction by the bolt 125 and the bolt 126 can be adjusted with (M8 × 1P) − (M6 × 0.75P) = 0.25 mm as a minimum unit.

  The hanging portion 13 is supported by the hanging rod support portion 127. When the chuck portion 15 is pushed down with respect to the suspension portion 13 by the inclination adjusting bolt 14 screwed into the suspension portion 13, the chuck portion 15 rotates about a suspension rod 13 </ b> A that is rotatably attached to the center of the suspension portion 13. Then, the relative posture between the suspended portion 13 and the chuck portion 15 changes.

[5] Action and Effect of Embodiment In this embodiment, the hanging position of the silicon polycrystalline raw material 2 is adjusted as follows.
When the silicon polycrystalline material 2 is gripped by the chuck portion 15 of the polycrystalline material gripping tool 9, the approximate center position can be grasped. While holding the silicon polycrystalline material 2, the vertical orientation of the silicon polycrystalline material 2 is adjusted by the tilt adjusting bolt 14.

The screw position of the bolt 125 and the bolt 126 of the horizontal position adjustment unit 12 is adjusted, and the horizontal position of the silicon polycrystalline material 2 is finely adjusted. Avoid drawing circular orbits with a certain radius.
When the silicon single crystal 3 is manufactured by the FZ furnace 1, the material holding plate 165 of the holding bolt 16 is inserted into the groove 2A of the silicon polycrystalline material 2, so that the silicon polycrystalline material 2 is thermally expanded during heating. Also, the raw material holding plate 165 is pushed out to the outside, and the long hole 151 and the long hole 152 are formed in the upper plate 15A and the lower plate 15B of the chuck portion 15 from the outer periphery toward the radial center. Therefore, there is no problem that the gripping force of the gripping bolt 16 is reduced or galling occurs.

  Since the heat shield plate 17 is disposed with a gap from the upper chuck portion 15, the silicon polycrystalline raw material 2 is heated by the high frequency induction heating coil 5, and the chuck portion 15 is thermally distorted due to the influence of the generated radiant heat. It is possible to suppress the displacement of the grip bolt 16 following the displacement. Therefore, even in the latter half of the production of the silicon single crystal 3 in the FZ furnace 1, even if the heat of the high-frequency induction heating coil 5 is likely to transfer heat to the polycrystalline material gripping tool 9, the heat shield plate 17 blocks the heat. The polycrystalline raw material gripping tool 9 is not heated and deformed by heat, and the gripping force does not decrease. Furthermore, by suppressing the heat transfer to the horizontal position adjusting unit 12, the gripping position is not decentered, and an increase in runout due to crystal growth can be suppressed.

A pair of female screw holes 123 of the position adjustment unit main body 121 are formed in XY directions orthogonal to each other. Therefore, the axis of the silicon polycrystalline raw material 2 can be aligned with the center of the FZ furnace 1 by adjusting the screwing positions of the bolts 125 inserted into the respective female screw holes 123. In particular, as described above, since the pitch of the M6 female screw hole 124 is smaller than that of the M8 female screw hole 123, the approximate position is adjusted with the M8 bolt 125, and the M6 bolt 126 is finely adjusted. It can be carried out. Therefore, since the silicon polycrystalline material 2 can be positioned with high accuracy, it is possible to prevent the silicon polycrystalline material 2 from drawing a circular orbit having a predetermined diameter during the growth of the silicon single crystal 3.
The gap between the position adjusting unit main body 121 and the grip bolt 16 can be reduced by the heat shield plate 17 made of stainless steel having a thickness of 0.8 mm or more. Therefore, a heat shielding effect can be ensured in a narrow gap, and deformation of the horizontal position adjusting unit 12 can be suppressed.

[6] Modification of Embodiments The present invention is not limited to the above-described embodiment, and includes modifications as described below.
In the above-described embodiment, the horizontal position adjusting unit 12 described above forms the female screw holes 123 and 124 in the X-axis direction and the Y-axis direction orthogonal to each other, and adjusts the horizontal position with two axes. The present invention is not limited to this. For example, six female screw holes may be formed in the position adjustment unit main body 121 so as to surround the support shaft 11, and bolts may be screwed into the respective female screw holes to adjust the horizontal position. Alternatively, three female screw holes 123 and 124 may be formed around the support shaft 11 and bolts may be screwed into the female screw holes 123 and 124 to adjust the horizontal position.

  In the embodiment described above, the female screw holes 123 facing each other are M8 screws conforming to JIS B0205 and the female screw holes 123 are M6 screws conforming to the same standard, but the present invention is not limited to this. For example, screws having different pitches conforming to the ISO standard may be employed, and further, the screws may be composed of screws conforming to the inch thread standard conforming to JIS B 0206.

In the above-described embodiment, the grip bolt 16 is provided at five locations on the chuck portion 15, but the present invention is not limited to this. That is, it is good also as a structure which provides the holding | grip bolt 16 six places and hold | maintains a silicon polycrystal raw material.
In addition, the specific structure, shape, and the like when implementing the present invention may be other structures as long as the object of the present invention can be achieved.

Next, examples of the present invention will be described. In addition, this invention is not limited to an Example.
[Example]
As described in the embodiment of the present invention, the horizontal position of the silicon polycrystalline raw material 2 is adjusted by the horizontal position adjusting unit 12 using the polycrystalline raw material gripping tool 9 provided with the horizontal position adjusting unit 12 and the heat shield plate 17. The silicon single crystal 3 was grown for the thing.
[Comparative example]
As shown in FIG. 6, the silicon single crystal 3 was grown using the polycrystalline raw material gripper 100 without the horizontal position adjusting unit and the heat shield plate.

The results are shown in FIG. 7 and FIG. In the case of FIG. 7 as a comparative example, it has been confirmed that the core runout tends to increase in the upward direction as the crystal grows, particularly in the latter half length.
In the case of FIG. 8 as an example, it is confirmed that by using the horizontal position adjusting unit 12 and the heat shield plate 17, the graph is flat, and the core runout is stable regardless of the lifting length. It was.
Although illustration is omitted, even when the displacement amount of the grip bolt 16 is confirmed by CFD (thermal fluid analysis), the displacement amount of the grip bolt 16 is 60% of the conventional amount by suppressing the thermal deformation of the chuck portion 15. It was confirmed that the results were suppressed to a certain extent.

  DESCRIPTION OF SYMBOLS 1 ... FZ furnace, 2 ... Silicon polycrystal raw material, 2A ... Groove part, 3 ... Silicon single crystal, 3A ... Melting zone, 4 ... Crystal holder, 5 ... High frequency induction heating coil, 6 ... Insulation cylinder, 8 ... Product single crystal Weight holding tool, 9 ... polycrystalline material gripping tool, 10 ... upper shaft, 11 ... support shaft, 12 ... horizontal position adjusting unit, 13 ... hanging portion, 13A ... hanging rod, 14 ... tilt adjusting bolt, 15 ... chuck portion 15A ... Upper plate, 15B ... Lower plate, 16 ... Holding bolt, 17 ... Heat shield, 121 ... Position adjusting body, 122 ... Hole, 123 ... Female screw hole, 124 ... Female screw hole, 125 ... Bolt, 126 ... Bolt DESCRIPTION OF SYMBOLS 127 ... Suspension rod support part, 151 ... Long hole, 152 ... Long hole, 161 ... Bolt, 162 ... Positioning nut, 163 ... Holding nut, 164 ... Heat-shielding plate support nut, 165 ... Raw material holding plate, 171 ... Slit .

Claims (5)

A polycrystalline raw material gripping tool for an FZ furnace for gripping a silicon polycrystalline raw material for an FZ (Floating Zone) furnace,
A support shaft for supporting the load of the polycrystalline silicon material;
A chuck portion through which a plurality of locking portions for locking the silicon polycrystalline raw material are inserted;
A horizontal position adjusting portion for adjusting the position of the plurality of locking portions in the horizontal direction;
A heat-shielding portion that is arranged with a gap between the plurality of locking portions and the horizontal position adjusting portion, and shields radiant heat from the silicon polycrystalline material; and
A polycrystalline raw material gripping tool for an FZ furnace, comprising: In the polycrystalline raw material gripping tool of the FZ furnace according to claim 1,
The horizontal position adjustment unit is
A position adjusting unit main body which is provided so as to surround the support shaft and in which a plurality of female screw holes are formed around the support shaft;
A plurality of bolts screwed into each of the female screw holes, the tips of which contact the support shaft;
A polycrystalline raw material gripping tool for an FZ furnace, wherein female screw holes and bolts facing each other have different screw pitches. In the polycrystalline raw material gripping tool of the FZ furnace according to claim 2,
The plurality of female screw holes are formed in a pair in a direction perpendicular to each other,
In the pair of female screw holes orthogonal to each other, one screw pitch is smaller than the other screw pitch,
A polycrystalline raw material gripping tool, wherein a screwing position of a bolt screwed into the pair of female screw holes is adjusted. In the polycrystalline raw material gripping tool of the FZ furnace according to any one of claims 1 to 3,
The chuck portion is composed of an upper plate and a lower plate,
The upper plate and the lower plate are each formed with a plurality of elongated holes from the outer circumference toward the radial center,
The polycrystalline raw material gripping tool for an FZ furnace, wherein the plurality of locking portions are inserted through the plurality of long holes. In the polycrystalline raw material gripping tool of the FZ furnace according to any one of claims 1 to 4,
The polycrystalline raw material gripping tool for an FZ furnace, wherein the heat shield part is made of a stainless steel plate having a thickness of 0.8 mm or more.