JP4849083B2 - Single crystal puller - Google Patents

Description

  The present invention relates to detection of leaking water in a single crystal pulling apparatus for growing a single crystal rod by the Czochralski method.

For example, an example of a conventional single crystal pulling apparatus using the Czochralski method used for manufacturing a semiconductor silicon single crystal rod will be described with reference to FIG.
As shown in FIG. 7, the single crystal pulling apparatus 101 rotates a chamber (pulling chamber) 102, a crucible 103 provided in the chamber 102, a heater 106 disposed around the crucible 103, and the crucible 103. The crucible holding shaft 110 to be rotated and its rotating mechanism (not shown), the seed chuck 114 holding the silicon seed crystal 113, the wire 115 pulling up the seed chuck 114, and the winding mechanism (not shown) for rotating or winding the wire 115 (Shown). The crucible 103 is provided with a quartz crucible 103a on the inner side containing the raw material silicon melt (hot water) 105 and a graphite crucible 103b on the outer side. A heater heat insulating material 107 is installed around the outside of the heater 106, and a heat insulating plate 104 is arranged at the bottom.

  Next, a single crystal growth method using the single crystal pulling apparatus 101 will be described. First, in a crucible 103, a high-purity polycrystalline raw material of silicon is melted by heating to a melting point (about 1420 ° C.) or higher. And the front-end | tip of the seed crystal 113 is made to contact or immerse in the approximate center part of the hot_water | molten_metal surface by unwinding the wire 115. FIG. Thereafter, the crucible holding shaft 110 is rotated in an appropriate direction, and the wire 115 is wound while being wound, and the seed crystal 113 is pulled up, whereby single crystal growth is started. Thereafter, a substantially cylindrical single crystal rod 112 can be obtained by appropriately adjusting the pulling speed and temperature.

  Both the quartz crucible 103a and the graphite crucible 103b in the single crystal pulling apparatus described above have high heat resistance, but they are somewhat brittle and have the disadvantage of poor impact resistance. Thus, when pulling the single crystal, if a polycrystalline raw material is put into the crucible 103, the impact may cause cracks in the crucible 103, and the molten liquid 105 may leak from there. In addition, hot water in the crucible 103 may be scattered around the crucible 103 when the polycrystalline raw material is charged. Further, when the crucible 103 is gradually deteriorated by use or the single crystal 112 being pulled is dropped, there is a risk that the crucible 103 is destroyed and almost all of the hot water flows out.

  Thus, when hot water flows out and scatters out of the crucible 103, it reaches the bottom of the chamber 102 from around the crucible 103, a metal portion such as the bottom of the chamber 102, a heater terminal or a crucible holding shaft, a crucible driving device, It will erode the lower cooling water piping. In particular, high-temperature silicon is highly reactive and has a strong erosion effect on metals, so that cooling water piping and the like are easily eroded, and there is a risk of causing a steam explosion. Moreover, if it overflows outside the apparatus, an accident or the like may occur due to the overflow.

Therefore, for example, in the single crystal pulling apparatus disclosed in Patent Document 1, an attempt is made to avoid such danger by disposing a hot water receiving tray having an internal volume capable of accommodating all the molten raw materials at the lower part of the crucible. Yes.
However, even if such a hot water leak tray is installed, even if it becomes a countermeasure when a hot water leak occurs, the occurrence of the hot water leak cannot be detected, and an immediate response such as turning off the power cannot be performed. Therefore, there is a possibility that effective and appropriate avoidance measures cannot be taken quickly.

  Moreover, as an example of a single crystal pulling apparatus provided with a hot water leak detector, there is a technique of Patent Document 2, and an optical visual sensor images the contact portion between the single crystal being pulled and the silicon melt, thereby leaking the hot water. Disclosed are a method for detecting an abrupt hot water surface position change by means of, and means for applying a voltage between the crucible support shaft and the wire holding the seed crystal, and detecting a change in the conductive state by a comparator to detect a hot water leak. Has been. These methods are extremely effective for detecting a hot water leak that occurs during pulling of a single crystal, but have a drawback that they cannot be detected when melting a raw material polycrystal lump that has the highest risk of hot water leak. Furthermore, when the molten metal surface position is changed by adding raw material polycrystals or changing the crucible position, there is a disadvantage that it is necessary to cancel the operation of the sensor each time.

  Therefore, as a method of avoiding such a problem, a technique is disclosed in which a hot water leak detector is provided at the bottom of the hot water tray, and the temperature of the bottom is constantly detected, and the hot water leak is determined from a change in the detected value. (See Patent Document 3 and Patent Document 4).

JP-A-9-221385 JP-A-11-180794 JP 2001-302387 A JP 2006-160538 A

By providing a hot water leak detector in this way, when a large amount of hot water leak has occurred, it has become possible to take measures such as detecting it and turning it off. If this happens, it will take time to detect the leak because it will not be possible to detect the leak or it will take time for the melt leaking from the crucible to reach the measurement position of the leak detector. there were.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a single crystal pulling apparatus that can quickly and accurately detect a hot water leak even when a relatively small amount of the hot water leak occurs. And

  In order to achieve the above object, according to the present invention, at least a single crystal ingot by the Czochralski method comprising a crucible for containing a raw material melt and a main chamber for storing a heater for heating the raw material melt. A single crystal pulling device for manufacturing a hot water leak receiving tray that is installed at the bottom of the main chamber and that contains a melt leaking from the crucible, and is provided in the hot water leak receiving tray and detects at least one of the hot water leaks. Two hot water leak detectors, and a heat insulating plate provided between the crucible and the hot water leak pan, and provided with a guiding structure for guiding the melt leaking from the crucible to the measurement position of the hot water leak detector; The molten metal leaking from the crucible is guided to the measurement position of the hot water leak detector by the induction structure of the heat insulating plate, and stored in the hot water leak tray, and the hot water leak detector Providing a single crystal pulling apparatus, characterized in that in order to detect the water leakage (claim 1).

  Thus, a hot water leak receiving tray that is installed at the bottom of the main chamber and stores the melt leaking from the crucible, and at least one hot water leak detector that is disposed in the hot water leak receiving tray and detects the hot water leak, A heat insulating plate provided between the crucible and the hot water leak tray, and provided with a guiding structure for guiding the melt leaking from the crucible to the measurement position of the hot water detector, from the crucible If the molten melt is guided to the measurement position of the hot water leak detector by the induction structure of the heat insulating plate and stored in the hot water leak receiving tray, and the hot water leak detector detects the hot water leak, a small amount of hot water leaks. Even in the case of the occurrence of the hot water, the hot water leak can be detected quickly and accurately.

At this time, the hot water detector is a thermocouple, the melt is guided by the heat insulating plate within a radius of 50 mm of the hot water detector, and the temperature of the hot water tray is detected by the thermocouple. It is preferable to detect a leak (claim 2).
Thus, the hot water detector is a thermocouple, and the melt is guided by the heat insulating plate within a radius of 50 mm of the hot water detector, and the temperature of the hot water tray is detected by the thermocouple. As long as it detects a hot water leak, it is possible to measure the temperature with high sensitivity and high accuracy instantly, and it is possible to easily determine whether or not there is a hot water leak by using the hot water leak detector.

Further, at this time, the induction structure of the heat insulating plate is a structure in which a rib is provided on the outer peripheral portion of the upper surface of the heat insulating plate, and a notch is provided in a part of the rib. It may be disposed so as to be positioned directly above the molten metal leak detector, and the melt may be guided from the notch to the measurement position of the molten metal leak detector (Claim 3).
Thus, the induction structure of the heat insulating plate is a structure in which a rib is provided on the outer peripheral portion of the upper surface of the heat insulating plate, and a notch is provided in a part of the rib. If it is arranged so as to be located directly above the molten metal leak detector and the melt is guided from the notch to the measurement position of the molten metal leak detector, the molten metal is detected with a simple structure. Even if a small amount of hot water leaks, the hot water leak can be detected quickly and accurately.

Further, at this time, the guiding structure is a structure in which a rib is provided on an outer peripheral portion of the upper surface of the heat insulating plate and a hole penetrating the heat insulating plate is provided, and the hole is the hot water leak detector. It is arrange | positioned so that it may be located right above, and a melt shall be guide | induced to the measurement position of the said molten metal leak detector from the said hole.
As described above, the guide structure is a structure in which a rib is provided on the outer peripheral portion of the upper surface of the heat insulating plate and a hole penetrating the heat insulating plate is provided, and the hole is the hot water leak detector. If it is arranged so that it is located directly above the melt, and the melt is guided from the hole to the measurement position of the leak detector, the melt is moved to the measurement position of the leak detector with a simple structure. Even when a small amount of hot water leaks, the hot water leak can be detected quickly and accurately.

Moreover, the cylinder which consists of carbon can be installed in the hole provided in the said heat insulation board at this time (Claim 5).
In this way, if a cylinder made of carbon is installed in the hole provided in the heat insulating plate, the melt can be prevented from entering the heat insulating plate, so that the melt leaked from the crucible has a hole. Easy to pass.

At this time, an inclined surface is provided on the upper surface of the heat insulating plate, and the melt leaking from the crucible can be guided to the measurement position of the hot water detector (Claim 6).
Thus, if the inclined surface is provided on the upper surface of the heat insulating plate and the melt leaking from the crucible is guided to the measurement position of the hot water leak detector, the melt is measured by the hot water detector. It can be efficiently guided by the position, and even when a small amount of hot water leaks, the hot water leak can be detected more reliably and quickly.

At this time, the heat insulating plate may have a sandwich structure in which carbon materials are combined on the upper and lower sides of a carbon fiber material.
Thus, if the heat insulating plate has a sandwich structure in which carbon materials are combined on the top and bottom of a carbon fiber material, the heat insulating plate can be made lightweight, excellent in heat resistance and thermal shock resistance, and The heat insulating effect of the heat insulating plate can be enhanced.

  According to the present invention, in the single crystal pulling apparatus, a hot water receiving tray that is installed at the bottom of the main chamber and that contains the melt leaking from the crucible, and at least one hot water leak that is disposed in the hot water receiving tray and detects the hot water leak. A detector, and a heat insulating plate provided between the crucible and the molten metal tray, and provided with a guiding structure for guiding the melt leaking from the crucible to the measurement position of the molten metal detector. The melt leaking from the crucible is guided to the measurement position of the hot water leak detector by the induction structure of the heat insulating plate, and stored in the hot water leak tray, and the hot water leak detector detects the hot water leak. Even when a small amount of hot water leaks, the hot water leak can be detected quickly and accurately. As a result, it is possible to take hot water leakage measures such as cutting off power at an early stage, and to ensure safety. Moreover, damage to the apparatus can be reduced, and melting of carbon parts in the furnace can be reduced.

Hereinafter, although an embodiment is described about the present invention, the present invention is not limited to this.
In the single crystal pulling apparatus, when the polycrystalline raw material is charged, there is a risk that the crucible cracks due to the impact and the molten liquid leaks therefrom. In addition, hot water in the crucible may be scattered around the crucible when the polycrystalline raw material is charged. Further, when the crucible gradually deteriorates due to use or the single crystal being pulled falls, there is a risk that the crucible will be destroyed and almost all of the hot water will flow out.

Therefore, as a method for coping with such a problem, a technique has been disclosed in which a hot water leak detector is provided at the bottom of the hot water receiving tray, the temperature of this bottom is constantly detected, and the hot water leak is determined from the change in the detected value. .
However, if a small amount of hot water leaks, it will not be possible to detect the hot water leak, or it will take time to detect the melt that has leaked from the crucible until it reaches the measurement position of the hot water detector. There was a problem that it took. In this case, countermeasures such as turning off the power will be delayed.

  Therefore, the present inventor has intensively studied to solve such problems. As a result, this problem is that the silicon melt leaked from the crucible hangs down on the upper surface of the heat insulating plate disposed between the crucible and the hot water leak tray, and then reaches the hot water leak tray after passing through its side surface. Furthermore, this is due to the length of the path of reaching the measurement position of the hot water leak detector, and the melt leaked from the crucible reaches the measurement position of the hot water leak detector arranged in the hot water leak tray in a short time. In this way, it is thought that if a heat insulating plate having a hot water leakage induction structure is arranged between the hot water tray and the crucible and the melt is guided to the measurement position of the detector, the hot water leak can be detected quickly and accurately. Completed the invention.

FIG. 1 is a schematic sectional view showing an example of a single crystal pulling apparatus according to the present invention.
As shown in FIG. 1, the single crystal pulling apparatus 1 includes a crucible 3 provided in a main chamber 2, a heater 6 disposed around the crucible 3, a crucible holding shaft 10 that rotates and moves the crucible 3, and The rotating mechanism (not shown) is provided.

  The crucible 3 is provided with a quartz crucible 3a on the inner side of the raw material melt (hot water) 5 and a graphite crucible 3b protecting the outer side. A heater 6 is disposed on the outer periphery of the crucible 3, and a heater heat insulating material 7 for preventing heat from the heater 6 from being directly radiated to the main chamber 2 around the outside of the heater 6. A metal heater energizing electrode 9 is attached to the lower part of the heater 6 and communicates with an external power source. The electrode 9 may be made of carbon at the top so that the metal part is not exposed in a high temperature furnace.

  A hot water leak tray 8 is disposed in contact with the inner wall surface at the bottom of the main chamber 2. This hot water leak tray 8 is composed of a bottom plate 8a and a cylindrical portion 8b, and the joint is joined by bolts or screws. Or what integrally molded the baseplate 8a and the cylinder part 8b may be used. Then, by inserting the hot water leak receiving tray 8 into the chamber bottom, the receiving tray 8 comes into close contact with almost the entire inner wall surface of the bottom of the main chamber 2.

  In the hot water leak receiving tray 8, a shaft sleeve 8c through which members passing through the bottom of the chamber such as the crucible holding shaft 10 and the heater energizing electrode 9 and the bottom plate 8a of the hot water receiving tray are screwed into the bottom plate 8a. Moreover, it is preferable that the height is the same level as the cylinder part 8b in each part, and the internal volume of the hot water receiving tray 8 obtained from the bottom plate 8a and the cylinder part 8b is equal to or greater than the volume of the total molten raw material 5. Is set. Further, when a part of the leaked water is solidified, the volume expands (the specific gravity of silicon is 2.54 for the melt and 2.33 for the solid). It is preferable that the volume is equal to or greater than the volume when the molten raw material is solidified. As the material of the hot water leak tray 8, a graphite material is suitable in terms of heat resistance, corrosion resistance, and workability, and isotropic graphite is preferably used among them.

  In the single crystal pulling apparatus 1 configured as described above, the silicon polycrystalline raw material charged into the crucible 3 is melted by the heater 6 to form the raw material melt 5. A seed crystal 13 mounted on a seed chuck 14 suspended from above by a wire 15 is immersed in the raw material melt 5 and pulled up at a predetermined speed while rotating the wire 15 and the crucible 3, thereby causing a predetermined single crystal rod 12. Can grow.

  In the single crystal pulling apparatus 1, for example, when a crucible 3 is cracked due to the impact of the raw material when a polycrystalline raw material is charged into the crucible 3, the melt 5 flows out of the crucible 3 from the crack, The outflowing melt 5 flows downward along the outer peripheral wall of the crucible 3 and falls toward the bottom of the main chamber 2.

  Here, according to the single crystal pulling apparatus 1 equipped with the hot water leak receiving tray 8, the hot water leak receiving tray 8 is disposed in contact with the inner wall surface of the bottom of the main chamber 2. The liquid 5 can be accommodated. Accordingly, it is possible to prevent the melt 5 from reaching the lower mechanism of the crucible 3 and to prevent dangers such as damage to the chamber and overflow of the melt that has flowed out of the apparatus. It has become.

  However, even if the leaked melt can be received in the tray 8, if the occurrence of the hot water leak itself is not detected, no action is taken such as turning off the heater, and the melt remains melted. Therefore, the hot water leak receiving tray 8 is provided with at least one hot water leak detector 11 for detecting hot water leaking from the crucible 3 and starting to accumulate in the hot water leak receiving tray 8. If the hot water leak detector 11 can detect the hot water leak, the melt 5 can be cooled and solidified by turning off the heater.

  The single crystal pulling apparatus 1 according to the present invention is disposed between the crucible 3 and the hot water receiving tray 8 so that the detector 11 can detect the hot water leak more reliably. A heat insulating plate 4 provided with a guiding structure for guiding the leaking melt 5 to the measurement position of the hot water leak detector 11 is provided.

  In this way, if the melt 5 leaking from the crucible 3 is guided by the heat insulating plate 4 and the hot water detector 11 detects hot water (temperature rise), even if a small amount of hot water leaks occurs, Occurrence can be detected quickly and accurately, and actions such as alarms and operation stop can occur immediately. As a result, accidents caused by hot water leaks can be prevented and safety can be ensured. Moreover, damage to the apparatus can be reduced, and melting of carbon parts in the furnace can be reduced.

At this time, the hot water leak detector 11 can be a thermocouple. Further, the molten metal 5 can be detected by guiding the melt 5 within the radius 50 mm of the hot water detector 11 (thermocouple) with the heat insulating plate 4 and detecting the temperature of the hot water receiving tray 8 with the thermocouple 11. .
Thus, the hot water detector 11 is a thermocouple, the melt 5 is guided by the heat insulating plate 4 within a radius of 50 mm of the hot water detector 11, and the temperature of the hot water tray is received by the thermocouple 11. As long as the hot water leak is detected by detecting the temperature, the temperature measurement can be instantaneously performed with high sensitivity and high accuracy, and the presence or absence of the hot water leak can be easily determined by the hot water leak detector 11.

FIG. 3 is a schematic view showing an example of a heat insulating plate 4 that can be used in the single crystal pulling apparatus 1 of the present invention.
As shown in FIG. 3, the rib 16 is provided in the outer peripheral part of the upper surface of the heat insulation board 4a. Further, a notch 17 is provided in a part of the rib 16 so that the melt 5 can be guided to the hot water receiving tray 8 from there. Here, the height of the rib 16 is not particularly limited, but may be, for example, 5 to 10 mm.
In the single crystal pulling apparatus 1 of the present invention, such a heat insulating plate 4a is arranged so that the notch 17 is positioned directly above the hot water leak detector 11 provided in the hot water leak receiving tray 8. The melt 5 can be guided from the notch 17 to the measurement position of the hot water leak detector 11.
Thus, the single crystal pulling apparatus 1 of the present invention can guide the melt 5 to the measurement position of the hot water detector 11 with a simple structure, and even when a small amount of hot water leaks, the hot water leaks. Can be detected quickly and accurately.

4A and 4B show an outline of another example of the heat insulating plate 4 that can be used in the single crystal pulling apparatus of the present invention.
As shown in FIGS. 4A and 4B, a rib 16 is provided on the outer peripheral portion of the upper surface of the heat insulating plate 4b. And the hole 18 penetrated to the heat insulation board 4b is provided, and the melt 5 can be guide | induced to the hot water leaking tray 8 from the hole 18. FIG. Here, the height of the rib 16 is not particularly limited, but may be, for example, 5 to 10 mm.
FIG. 2 is a schematic view showing another example of the single crystal pulling apparatus of the present invention using such a heat insulating plate 4b.
As shown in FIG. 2, the single crystal pulling apparatus 1 ′ arranges the heat insulating plate 4 b so that the hole 18 is positioned directly above the hot water detector 11 provided in the hot water receiving tray 8. The melt 5 can be guided from 18 to the measurement position of the hot water leak detector 11.

At this time, as shown in FIGS. 4A and 4B, a cylinder 19 made of carbon can be installed in the hole 18 provided in the heat insulating plate 4b.
In this way, if the cylinder 19 made of carbon is installed in the hole 18 provided in the heat insulating plate 4b, the melt 5 can be prevented from entering the heat insulating plate 4b, so that it leaks from the crucible 3. The melt 5 can easily pass through the hole 18.

At this time, an inclined surface is provided on the upper surface of the heat insulating plate 4, and the melt 5 leaking from the crucible 3 can be guided to the measurement position of the hot water leak detector 11.
5A and 5B are schematic views showing an example of a heat insulating plate in which the inclined surface 20 is provided on the heat insulating plate 4a in which the notch 17 is provided in a part of the rib 16, as shown in FIG. is there.
As shown in FIGS. 5A and 5B, ribs 16 are provided on the outer peripheral portion of the upper surface of the heat insulating plate 4c. Further, a notch 17 is provided in a part of the rib 16, and the bottom of the inclined surface 20 is positioned at the notch 17. The melt 5 can be guided from the notch 17 to the hot-water leaking tray 8.

6A and 6B are schematic views showing an example of a heat insulating plate in which an inclined surface 20 is provided on a heat insulating plate 4b having a through hole 18 as shown in FIG.
As shown in FIGS. 6A and 6B, ribs 16 are provided on the outer peripheral portion of the upper surface of the heat insulating plate 4d. Further, a hole 18 penetrating the heat insulating plate 4d is provided, and the bottom portion of the inclined surface 20 is positioned at the hole 18. The melt 5 can be guided from the hole 18 to the hot-water leaking tray 8.

  In this way, if the inclined surface 20 is provided on the upper surface of the heat insulating plate 4 and the melt 5 leaking from the crucible 3 is guided to the measurement position of the hot water leak detector 11, the melt 5 is detected. Therefore, even when a small amount of hot water leaks, the hot water leak can be detected more reliably and quickly.

At this time, the heat insulating plate 4 may have a sandwich structure in which carbon materials are combined on the top and bottom of a carbon fiber material.
Thus, if the said heat insulation board 4 is a sandwich structure which combined the carbon material on the upper and lower sides of the carbon fiber material, the heat insulation board can be made lightweight and excellent in heat resistance and thermal shock resistance, And the heat insulation effect of a heat insulation board can be heightened.

  Also, a plurality of the hot water leak detectors 11 can be provided. For example, two hot water leak detectors 11 are provided, for example, two cutouts are provided in the heat insulating plate 4a as shown in FIG. 3, and the respective cutouts are directly above the two hot water leak detectors 11, respectively. Can be configured. With such a configuration, it is possible to further improve the detection accuracy of the hot water leak and to grasp the hot water leak position. Alternatively, one of the two hot water leak detectors 11 may be used as a spare and provided for the failure of one of the hot water leak detectors 11.

  As described above, according to the present invention, in the single crystal pulling apparatus, a hot water receiving tray that is installed at the bottom of the main chamber and stores the melt leaking from the crucible, and the hot water leaking tray that is disposed in the hot water leak receiving tray is detected. And a guiding structure that is disposed between the crucible and the molten metal tray and guides the melt leaking from the crucible to the measurement position of the molten metal detector. A molten metal leaking from the crucible is guided to the measurement position of the hot water leak detector by the induction structure of the heat insulating plate and stored in the hot water leak tray, and the hot water leak detector detects hot water. Since a leak is detected, even when a small amount of hot water leaks, the hot water leak can be detected quickly and accurately. As a result, measures such as turning off the hot water leak can be taken early and safety can be ensured. Moreover, damage to the apparatus can be reduced, and melting of carbon parts in the furnace can be reduced.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples of the present invention, but the present invention is not limited to these.

(Example)
Using a single crystal pulling apparatus as shown in FIG. 1 provided with a heat insulating plate as shown in FIG. 5, 320 kg of silicon polycrystal is charged in a quartz crucible having a diameter of 32 inches (80 cm), and a silicon single crystal having a diameter of 300 mm is obtained. Manufactured. Thereafter, a small amount of hot water leak was intentionally caused by the remaining hot water remaining in the quartz crucible, and the time until detection of the hot water leak was measured.
As a result, as shown in FIG. 8 (A), the hot water leak can be detected in 0.5 hours after the hot water leak occurs, which is greatly improved as compared with the comparative example of 4 hours. I understood. And it was possible to ensure safety in a short time by turning off the power immediately after detection of the hot water leak.
As described above, it was confirmed that the single crystal pulling apparatus of the present invention can detect the molten metal leak quickly and accurately even when a small amount of molten metal leak occurs.

(Comparative example)
Using a conventional single crystal pulling apparatus as shown in FIG. 7A provided with a conventional heat insulating plate not provided with a guiding structure for inducing a melt as shown in FIG. A silicon single crystal was manufactured under the same conditions, and the same amount of hot water leak as that of the example was intentionally generated, and the time until the hot water was detected was measured.
As a result, since the amount of hot water leaked was small, as shown in FIG. 8 (B), it took time to detect the hot water leak, and the hot water leak was detected after 4 hours.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits the same effects. Are included in the technical scope.

  For example, the present invention has been described above by taking as an example the case where a silicon single crystal is grown by the Czochralski method, but the present invention is not limited to the production of a silicon single crystal, but by the Czochralski method. The present invention can be applied to any type of single crystal growth apparatus, and MCZ (Magnetic Field Applied Czochralski) for applying a magnetic field to the melt is applied to the Czochralski method referred to in the present invention. In addition to the above methods, it is needless to say that the present invention can also be used for an apparatus for growing a single crystal such as a compound semiconductor using the LEC (Liquid Encapsulated Czochralski) method.

It is the schematic which showed an example of the single crystal pulling apparatus which concerns on this invention. It is the schematic which showed another example of the single crystal pulling apparatus which concerns on this invention. It is the perspective view which showed an example of the heat insulation board which can be used by this invention. It is the perspective view which showed another example of the heat insulation board which can be used by this invention. (A) The perspective view of a heat insulating board. (B) The perspective view which showed the cross section of the heat insulation board. It is the perspective view which showed an example of the heat insulation board with the inclined surface which can be used by this invention. (A) The perspective view of a heat insulating board. (B) The perspective view which showed the cross section of the heat insulation board. It is the perspective view which showed another example of the heat insulation board with the inclined surface which can be used by this invention. (A) The perspective view of a heat insulating board. (B) The perspective view which showed the cross section of the heat insulation board. It is the schematic which shows an example of the conventional single crystal pulling apparatus. (A) Schematic of a conventional single crystal pulling apparatus. (B) The perspective view of the conventional heat insulating board. It is a graph which shows the result of an Example and a comparative example. (A) The graph which shows the result of an Example. (B) The graph which shows the result of a comparative example.

Explanation of symbols

1, 1 '... single crystal pulling device, 2 ... main chamber, 3 ... crucible,
4, 4a, 4b, 4c, 4d ... heat insulating plate, 5 ... melt, 6 ... heater,
7 ... Heater insulation material, 8 ... Hot water leak tray, 9 ... Heater energizing electrode,
10 ... crucible holding shaft, 11 ... leak detector, 12 ... single crystal,
13 ... Seed crystal, 14 ... Seed chuck, 15 ... Wire, 16 ... Rib,
17 ... Notch, 18 ... Hole, 19 ... Tube, 20 ... Inclined surface.

Claims (7)

  A single crystal pulling apparatus for manufacturing a single crystal ingot by the Czochralski method, comprising at least a crucible for storing a raw material melt and a main chamber for storing a heater for heating the raw material melt, the main chamber A hot-water leaking tray that is installed at the bottom of the hot-water tank and accommodates the melt that leaks from the crucible, at least one hot-water leak detector that is disposed in the hot-water leak tray and detects the hot water leak, and the crucible and the hot-water leak tray And a heat insulating plate provided with a guiding structure for guiding the melt leaking from the crucible to the measurement position of the molten metal leak detector, and the melt leaking from the crucible is It is characterized in that it is guided to the measurement position of the hot water leak detector by a heat insulating plate guiding structure and accommodated in the hot water leak tray, and the hot water leak detector detects the hot water leak. Single crystal pulling apparatus.   The molten metal detector is a thermocouple, and the molten metal is guided by the heat insulating plate within a radius of 50 mm of the molten metal detector, and the temperature of the molten metal tray is detected by the thermocouple to detect the molten metal. The single crystal pulling apparatus according to claim 1, wherein:   The induction structure of the heat insulating plate is a structure in which a rib is provided on the outer peripheral portion of the upper surface of the heat insulating plate, and a notch is provided in a part of the rib. 3. The unit according to claim 1, wherein the unit is disposed so as to be located immediately above the vessel, and guides the melt from the notch to a measurement position of the leak detector. Crystal pulling device.   The guide structure is a structure in which a rib is provided on the outer peripheral portion of the upper surface of the heat insulating plate, and a hole penetrating the heat insulating plate is provided, and the hole is directly above the leak detector. The single crystal pulling apparatus according to claim 1, wherein the single crystal pulling apparatus is disposed so as to be positioned and guides the melt from the hole to a measurement position of the molten metal leak detector.   The single crystal pulling apparatus according to claim 4, wherein a cylinder made of carbon is installed in a hole provided in the heat insulating plate.   An inclined surface is provided on the upper surface of the heat insulating plate, and the melt leaking from the crucible is guided to a measurement position of the hot water leak detector. The single crystal pulling apparatus according to item 1. The single-crystal pulling apparatus according to any one of claims 1 to 6, wherein the heat insulating plate has a sandwich structure in which carbon materials are combined above and below a carbon fiber material.

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