JP5488544B2 - Single crystal growth equipment - Google Patents

Description

  The present invention relates to a single crystal growing apparatus for growing a single crystal rod by the Czochralski method.

  An example of a conventional single crystal growth 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. 3, the single crystal growth apparatus 101 includes a main chamber 102, a crucible 103 provided in the main chamber 102, a heater 106 disposed around the crucible 103, and a crucible holding device that rotates the crucible 103. A shaft 110 and its rotation mechanism (not shown), a seed chuck 114 for holding a silicon seed crystal 113, a wire 115 for pulling up the seed chuck 114, and a winding mechanism (not shown) for rotating or winding the wire 115. It is prepared for. The crucible 103 is provided with a quartz crucible 103a on the inner side containing the raw material melt 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 below the crucible 103.

  The single crystal growing apparatus 101 includes a hot water receiving tray 108 that is disposed at the bottom of the main chamber 102 and accommodates the melt leaked from the crucible 103. The hot water receiving tray 108 is disposed along the inner wall thereof. A tray inner wall heat insulating material 109 is provided.

  Next, a single crystal growth method using the single crystal growth apparatus 101 will be described. First, in the crucible 103, a high-purity polycrystalline raw material of silicon is heated to a melting point (about 1420 ° C.) or higher by a heater 106 and melted. Then, the tip of the seed crystal 113 is brought into contact with or immersed in the substantially central portion of the surface of the melt 105 by unwinding the wire 115. 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 and the graphite crucible in the above-described single crystal growth apparatus have high heat resistance, but have a drawback of being somewhat brittle and poor in impact resistance. Therefore, when the single crystal is pulled, if the polycrystalline raw material is put into the crucible, the crucible may be cracked by the impact, and the molten liquid (hot water) may leak from there. 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 when the single crystal being pulled is dropped due to an earthquake or the like, the crucible may be destroyed and almost all of the hot water may flow out.

  In this way, when hot water flows out and scatters outside the crucible, it reaches the bottom of the main chamber from around the crucible, metal parts such as the bottom of the main chamber, the terminal for heater or the crucible holding shaft, the crucible driving device, and the lower cooling It will erode water pipes. In particular, high-temperature silicon is highly reactive and has a strong erosion effect on metals, so safety measures are required.

  In preparation for this, Patent Literature 1 and the like provide a hot water leak tray made of isotropic graphite material. Since it is necessary to provide a space for securing the entire amount of the melt that has leaked, there is a problem that heat is likely to leak.

  Therefore, Patent Document 2 secures a hot water leakage capacity while affixing a carbon fiber molding material (heat insulating material) in the hot water receiving tray to reduce heat loss. However, as the diameter has increased in recent years, the amount of hot water has increased and the capacity of the hot water leaking tray has also increased, so heat loss from this space cannot be ignored, and it can be said that there is a problem from the viewpoint of power saving.

  In order to reduce this heat loss, it is effective to place a heat insulating material (such as a low-density carbon fiber material used in the CZ method or the like) in the hot water leak receiver. Actually, although reduction of heat loss is not the main purpose, Patent Document 3, Patent Document 4, Patent Document 5, and the like disclose a method of filling permeable carbon, carbon fiber material, or the like capable of absorbing a melt.

JP 2002-68886 A WO2001 / 064976 JP-A-5-270967 JP 2003-55090 A JP 2008-7334 A JP 2001-302387 A JP 2009-215126 A

  However, these disclosed methods require a sufficient thickness in order for the heat insulating material or the like to absorb the entire amount of the melt. From the viewpoint of preventing heat loss, it is preferable that the heat insulating material is thick. When the heat insulating material is thick, the temperature of the heat insulating material on the side of the hot water receiving tray is lower than that on the crucible side. In a heat insulating material having such a low temperature part, if a high temperature melt leaks all at once, the melt may reach the low temperature part below the heat insulating material, and the whole heat insulating material may absorb the melt. . However, in many cases, hot water leaks over a small amount of time. In such a case, in a thick heat insulating material, since it becomes low temperature so that it goes down, it will be cooled in the middle of a melt going down through the fiber of a heat insulating material, and will solidify in the middle of a heat insulating material. Since the melt does not reach the heat insulating material below the portion where the melt is solidified, a region where the molten metal cannot be absorbed is generated.

  Therefore, it is very dangerous to expect all of the thick heat insulating materials exemplified in Patent Document 3, Patent Document 4, Patent Document 5, and the like as the amount of leaking hot water. In addition, in this way, if the leaked melt stops in the middle of the heat insulating material, discovery of the hot water leak is delayed. Further, even if the entire amount of the hot water leak is received in the hot water leak tray, it is desirable to detect the fact that the hot water leak has occurred at an early stage and to start dealing with it early.

  From this point of view, Patent Document 6 discloses a technique for introducing a hot water leak sensor to detect a hot water leak. Furthermore, Patent Document 7 discloses a technique for detecting a hot water leak earlier by providing a guide path in a heat insulating plate introduced under the crucible to guide the hot water leak to a sensor. However, in these techniques, the lower heat insulating structure is not sufficient, and it can be said that there is a problem from the viewpoint of power saving.

  The present invention has been made in view of the above problems, and a sufficient heat insulating material can be provided at the bottom of the main chamber to prevent heat loss and to obtain an energy saving effect. An object of the present invention is to provide a CZ method single crystal growing apparatus capable of ensuring safety because it can be guided to the lower part in the leak tray and absorbed without solidifying in the middle of the heat insulating material.

In the present invention, the main chamber for storing the crucible for storing the raw material melt and the heater for heating the raw material melt, and the carbon material for storing the melt leaked from the crucible installed at the bottom of the main chamber. A single crystal growing apparatus for growing a single crystal ingot by the Czochralski method comprising a hot water leak receiving tray,
A lower guide member installed between the crucible and the hot water leak tray, having a guiding structure for guiding the hot water leaked melt leaked from the crucible and dropping it to the hot water leak tray,
The hot water leak tray has a tray filling heat insulating material made of carbon fiber filled in the space in the hot water leak tray,
The volume of the saucer filled heat insulating material is not less than the maximum capacity of the raw material melt accommodated in the crucible,
The tray filling heat insulating material has a guide path for guiding the dropped molten metal melt further guided to the lower part of the molten metal leak receiving tray at a position where the molten metal melt guided by the lower guiding member falls. There is provided a single crystal growing apparatus characterized by being.

  Thus, when a hot water leak occurs, the melt that has fallen on the lower guide member flows along the guide structure of the lower guide member, falls from a predetermined position to the saucer filling heat insulating material of the hot water saucer, Since it can be guided to the bottom of the leaking metal tray through the induction path of the filled heat insulating material, it is possible to guide the molten metal to the lower end with the lowest temperature at a temperature that can exist as a liquid. For this reason, sufficient heat sinks are placed at the bottom of the main chamber to prevent heat loss and save energy, but the melt will solidify in the middle of the insulation and melt into the insulation below it. It is possible to avoid a situation where the liquid is not absorbed. Thereby, it becomes a CZ method single crystal growth apparatus which can reduce heat loss and can save power while maintaining a safe state in which a sufficient hot water leakage capacity is secured.

  Moreover, it is preferable that the guide path of the said saucer filling heat insulating material is a through-hole which penetrates a saucer filling heat insulating material to a perpendicular direction.

  Such a through-hole is the simplest guideway that does not place the saucer-filling heat insulating material in the part where the melt falls, and the molten metal leaked melt can reach the lowest end through this through-hole. Become.

  Furthermore, a carbon material cylinder is provided in the through hole of the saucer-filling heat insulating material, and the carbon material cylinder has a lower end portion of the carbon material cylinder in which the melt led to the lower part of the leaking saucer through the carbon material cylinder It is preferable that it is arrange | positioned in the through-hole of a saucer filling heat insulating material so that it can flow out out of a cylinder.

  As a result, it is possible to more reliably avoid the possibility that the molten metal melt is absorbed by the tray filling heat insulating material in the middle of the through hole and cannot reach the lower end, and the molten metal melt is further guided to the lower part of the molten metal tray. And the led melt can flow out of the cylinder at the lower end of the carbon cylinder. Thereby, it becomes a single crystal growth apparatus with which safety | security was ensured, preventing a heat loss and obtaining the energy-saving effect.

  Moreover, it is preferable that the said carbon material cylinder has a straight body part by which the several hole was opened in the side surface.

  As a result, even if the molten metal leaks to the molten metal leaking tray and falls to the temperature at which it solidifies at the same time, even if the lower end of the carbon material cylinder placed in the through hole of the tray filled heat insulating material is blocked The molten metal melt can flow out to the tray filling heat insulating material through the plurality of holes on the side surface. As a result, a single crystal growth apparatus is obtained in which safety is ensured while preventing heat loss more reliably and obtaining an energy saving effect.

  Furthermore, it is preferable that the tray filling heat insulating material can be divided into a plurality of heat insulating materials.

  In this way, it is possible to divide, and if it is not necessary to integrally mold it according to the shape of the hot water leak tray, it is possible to reduce the molding cost of the heat insulating material. It is possible to keep the cost low by exchanging only the permeated part and reusing the other part. Moreover, since the divided saucer filling heat insulating material floats by the buoyancy of the melt led to the lower part of the hot water leak receiving tray through the guide passage of the saucer filled heat insulating material, it is possible to reliably ensure the amount of hot water leak received. Thereby, it becomes a single crystal growth apparatus with which safety was ensured more.

  Moreover, it is preferable that the said lower induction | guidance | derivation member is comprised by at least one of a heat insulation board and a lower heater.

  Since the heat insulating plate and the lower heater are located under the crucible, if the lower induction member is constituted by either one of the heat insulating plate and the lower heater, or both of the heat insulating plate and the lower heater in this way, it will leak from the crucible. Thus, the single crystal growing apparatus can efficiently drop the molten liquid through the induction structure onto the saucer filling heat insulating material of the leaking saucer.

  Further, the heat insulating plate has a plate-like carbon material on at least the crucible surface side of the plate-like heat insulating material made of carbon fiber, and the plate-like carbon material has a guide wall or a tapered shape as a guide structure. Preferably there is.

  By using such a guide member, the molten metal leaked from the crucible is appropriately guided by the guiding structure and dropped to the molten metal tray, and the dropped molten metal is guided to the tray filling heat insulating material. It becomes a single crystal growth apparatus that can be guided to

  Furthermore, it is preferable that the said hot water leak tray has a sensor which detects a hot water leak directly under the guide path of a tray filling heat insulating material.

  As a result, the molten metal leaked into the receiving path of the saucer-filled heat insulating material can be quickly found, and the single crystal growing apparatus can be secured more safely.

  As described above, in the case of the CZ method single crystal growing apparatus of the present invention, when a hot water leak occurs, the melt that has fallen on the lower guide member flows along the guide structure of the lower guide member, From the position of the hot water leaking tray to the saucer filling heat insulating material, passing through the receiving path of the saucer filling heat insulating material and being guided to the bottom of the hot water leaking saucer, so that the temperature at which the hot water melt can exist as a liquid, It can be guided to the lower end of the lowest temperature. Therefore, in the case of the CZ method single crystal growth apparatus of the present invention, the melt is placed in the middle of the heat insulating material while arranging a sufficient saucer filled heat insulating material at the bottom of the main chamber to prevent heat loss and obtain an energy saving effect. It is possible to avoid a state in which the melt is hardened and the melt is no longer absorbed. As a result, the present invention can provide a CZ method single crystal growing apparatus that can reduce heat loss and save power while maintaining a safe state in which a sufficient capacity for receiving molten metal is sufficiently secured. .

It is a figure which shows the 1st form of the CZ method single crystal growth apparatus of this invention. It is a figure which shows the 2nd form of the CZ method single crystal growth apparatus of this invention. It is a figure which shows an example of the conventional CZ method single crystal growth apparatus. It is a figure which shows an example of the heat insulation board as a lower induction | guidance | derivation member of the CZ method single crystal growth apparatus of this invention. It is a figure which shows the other form of the heat insulation board as a lower induction | guidance | derivation member of the CZ method single crystal growing apparatus of this invention. It is a figure which shows the form of the carbon material cylinder of the CZ method single crystal growth apparatus of this invention. It is a figure which shows another form of the carbon material cylinder of the CZ method single crystal growth apparatus of this invention.

  Hereinafter, the present invention will be described in more detail, but the present invention is not limited thereto. There has been a demand for the development of a CZ method single crystal growth apparatus that can detect hot water leaks promptly while preventing heat loss. First, an experimental example for explaining the problem of hot water leakage when there is no pan-filling heat insulating material having the guide path of the present invention is shown.

[Experiment example: Hot water leak]
A simple furnace simulating a CZ method single crystal growth apparatus equipped with a heater and a crucible made of isotropic graphite was prepared. A hole was made in the lower end of the crucible, and a silicon raw material was put therein, and when the raw material melted, a small amount of hot water leaked. Also, the bottom of a simple furnace that imitates the CZ method single crystal growth apparatus, and below the crucible is an isotropic graphite hot water in which an inner wall heat insulating material made of carbon fiber material is arranged on the inner wall as shown in FIG. A leak pan was placed. At this time, the thickness of the inner wall heat insulating material of the tray was 10 cm. The inner wall insulating material for the saucer has a line density of 0.1 to 1.0 g / cm ³ , and the most standard one is 0.13 to 0.16 g / cm ³ . In this experimental example and example, the standard bulk density was used.

  Electric power was supplied to a simple furnace heater simulating a CZ method single crystal growth apparatus, and heating was started. After confirming that a part of the silicon raw material contained in the crucible started to dissolve, about 5 minutes passed, the electricity was turned off and the system was cooled. After the inside of the furnace was cooled, the inner wall heat insulating material in the saucer in the hot water leaking saucer was taken out and observed. As a result, the silicon melt penetrated from the surface of the inner wall heat insulating material to a thickness of several centimeters, and there was no penetration of the silicon melt from there. In addition, solid silicon bulges on the surface of the inner wall heat insulating material.

  From the above, when a small amount of hot water leakage occurred, it was confirmed that the silicon melt was solidified near the surface of the inner wall heat insulating material of the saucer, and the silicon melt that could not be absorbed remained on the surface. Therefore, it has been found that when this state continues and a large amount of hot water leaks, only the upper part of the inner wall heat insulating material of the saucer functions as a hot water leak receiver, and hot water may overflow from the hot water leak pan. .

  As a result of intensive studies on the above problems, the present inventors have arranged a sufficient saucer-filling heat insulating material at the bottom of the main chamber to obtain an energy saving effect, while the leaked melt is guided to the lower guiding member guiding structure. The present invention finds that safety can be ensured by guiding the heat sink to the lower part of the hot water leaking saucer through the guide path of the saucer filling heat insulating material, so that the heat can be absorbed by the saucer filling heat insulating material without solidifying in the middle of the present invention. Was completed.

[Single crystal growth equipment]
In the present invention, the main chamber for storing the crucible for storing the raw material melt and the heater for heating the raw material melt, and the carbon material for storing the melt leaked from the crucible installed at the bottom of the main chamber. A single crystal growing apparatus for growing a single crystal ingot by the Czochralski method comprising a hot water leak receiving tray,
A lower guide member installed between the crucible and the hot water leak tray, having a guiding structure for guiding the hot water leaked melt leaked from the crucible and dropping it to the hot water leak tray,
The hot water leak tray has a tray filling heat insulating material made of carbon fiber filled in the space in the hot water leak tray,
The volume of the saucer filled heat insulating material is not less than the maximum capacity of the raw material melt accommodated in the crucible,
The tray filling heat insulating material has a guide path for guiding the dropped molten metal melt further guided to the lower part of the molten metal leak receiving tray at a position where the molten metal melt guided by the lower guiding member falls. There is provided a single crystal growing apparatus characterized by being. Hereinafter, a specific structure of the CZ method single crystal growing apparatus of the present invention will be described with reference to FIGS.

  1 and 2 show first and second embodiments of the CZ method single crystal growing apparatus of the present invention. A single crystal growing apparatus 1, 1 ′ for producing a single crystal ingot by the Czochralski method includes a main chamber 2 for storing a crucible 3 for storing a raw material melt 5 and a heater 6 for heating the crucible 3. At the bottom of the main chamber 2, a hot water receiving tray 8 made of a carbon material for containing the hot water leaking melt 17 leaking from the crucible 3 is installed. A volume capable of accommodating the entire amount of the melt in 8 is secured. Under the crucible 3 in the single crystal growing apparatuses 1 and 1 ′, a heat insulating plate 4 (lower induction structure) is mainly provided to prevent heat loss.

  As a first feature of the present invention, a shape is formed on the heat insulating plate 4 to guide the molten metal 17 leaking from the crucible 3 to a predetermined position so that the molten liquid falls from a desired position. A heat insulating plate 4 having a devised guiding structure 4a, 4b, 4c, 4d may be used. Further, as a second feature of the present invention, the space in the hot water leaking tray 8 is filled with a tray filling heat insulating material 16 made of carbon fiber, and a portion of the melt 17 guided by the heat insulating plate 4 falls in the tray. There is a case where the guide path 16a of the tray filling heat insulating material is formed so that the filling heat insulating material 16 is not disposed. The above two structures are the main points of the present invention.

  By combining these two structures, as shown in FIGS. 1 and 2, when a hot water leak occurs, the melt 17 falls on the heat insulating plate 4 and then the heat insulating plate 4 is guided to the guiding structure 4 a. , 4b, 4c, 4d, and falls from a predetermined position. Subsequently, it passes through the guide path 16a of the saucer filling heat insulating material 16 and falls to the hot water leaking saucer 8 disposed at the bottom of the main chamber 2 and accumulates there. The saucer-filling heat insulating material 16 is preferably made of a material made of low-density carbon fiber, can absorb the accumulated melt 17 therein, and does not reduce the volume of the molten metal in the leaking saucer 8.

  By guiding the leaked melt 17 as a liquid at the lowest temperature, the melt is solidified in the middle of the saucer-filling heat insulating material 16, and the melt is melted at a lower temperature. It is possible to avoid a situation in which 17 does not flow. Thereby, it is possible to estimate the entire volume of the tray filling heat insulating material 16 as a volume for absorbing the molten metal melt. As a result, the CZ method single crystal growing apparatus 1 or 1 ′ can reduce heat loss and save power while maintaining a safe state in which a sufficient amount of hot water leakage is ensured.

  1 and 2, the case where the heat insulating plate 4 is mounted as the lower induction member under the crucible is described. However, the lower heater may be installed as the lower induction member instead of the heat insulating plate 4. It is also possible to provide a guiding structure. Moreover, in order to detect a hot water leak early, it is preferable to arrange | position the sensor 11 which detects a hot water leak directly under the guide path 16a of a saucer filling heat insulating material.

  The configuration other than the above can be the same as the conventional one. For example, a crucible holding shaft 10 for rotating the crucible 3 and its rotation mechanism (not shown), a seed chuck 14 for holding a silicon seed crystal 13, a wire 15 for pulling up the seed chuck 14, and a wire 15 for rotating or winding. A take-up mechanism (not shown) can be provided. Further, the crucible 3 is provided with a quartz crucible 3a on the inner side containing the raw material melt 5 and a graphite crucible 3b on the outer side. Further, a heater heat insulating material 7 is installed around the outside of the heater 6. Moreover, you may arrange | position a thin plate-shaped saucer inner wall heat insulating material to an inner wall. Hereinafter, the present invention will be described in more detail.

[Lower induction member]
The CZ method single crystal growing apparatus of the present invention includes a lower guiding member having a guiding structure for guiding the molten metal leaked from the crucible and dropping it between the crucible and the molten metal receiving tray. Have. Such a lower induction member is preferably composed of at least one of a heat insulating plate and a lower heater. Since the heat insulating plate and the lower heater are located under the crucible, if the lower induction member is constituted by either one of the heat insulating plate and the lower heater, or both of the heat insulating plate and the lower heater in this way, it will leak from the crucible. The molten melt can be dropped to a predetermined position of the saucer filling heat insulating material of the leaking saucer through the guide structure.

  Furthermore, the lower guide member provided between the crucible and the hot water receiving tray can be a heat insulating plate whose main purpose is to reduce heat loss. Such a heat insulating plate preferably has a plate-like carbon material on at least the crucible surface side of the plate-like heat insulating material made of carbon fiber. Thus, by using a sandwich structure heat insulating material in which a carbon material such as an isotropic graphite material is arranged on the upper surface and the lower surface, for example, in the case of silicon crystal growth, silicidation resistance can be imparted to the heat insulating material of the heat insulating plate. Also, a heat insulating plate having a plate-like carbon material in which a guiding structure for guiding the melt to a desired position is formed without allowing the melt leaking from the crucible to penetrate into the heat insulating material for the heat insulating plate. Can do.

(Induction structure of lower induction member)
The lower guiding member in the present invention has a guiding structure for guiding the molten metal leaking from the crucible and dropping it to the molten metal receiving tray. As this guiding structure, it is preferable to form a guiding wall or a tapered shape on the plate-like carbon material of the heat insulating plate. The molten metal melt led by this guiding structure is guided by the guide wall of the heat insulating plate to the outer peripheral portion of the heat insulating plate, and falls from there to the hot water receiving tray, or by the taper shape of the heat insulating plate, the through hole of the heat insulating plate From there, it can drop into a leaking saucer. Specifically, an induction structure can be formed by providing an uneven shape that serves as a guide wall for melt induction or a tapered shape on the carbon material disposed on the upper surface of the heat insulating plate. it can.

  In FIG. 1 and FIG. 4, guide walls 4 a are provided on the outer peripheral portion and the inner side of the heat insulating plate 4 on the carbon material, and the melt is dropped downward from a cut 4 b in which a part of the guide wall 4 a on the outer peripheral portion is cut out. The form of the heat insulating plate 4 is shown. FIG. 2 shows an example in which a tapered shape 4c is provided on the carbon material of the heat insulating plate 4 and the melt is guided to the through hole 4d of the heat insulating plate. Further, FIG. 5 shows a form of the heat insulating plate 4 in which guide walls 4a are provided on the outer peripheral portion and the inner side of the heat insulating plate 4 on the carbon material and the melt is dropped from the through holes 4d of the heat insulating plate. In addition to this, it is also possible to form a guide wall for introducing the melt into the through hole. In addition, in order to prevent the melt from penetrating into the heat insulating material of the heat insulating plate, the induction structure is formed of a carbon material or the like in the through hole of the heat insulating plate or the notch portion of the induction wall as shown in FIGS. More preferably.

[Tray leak tray]
The CZ method single crystal growing apparatus of the present invention includes a hot water leak receiving tray made of a carbon material that is installed at the bottom of a main chamber and that contains a melt leaked from a crucible. The hot water leak tray in the present invention has a pan filling heat insulating material made of carbon fiber filled in the space in the hot water leak tray.

(Guiding path for tray filling insulation)
The saucer-filling heat insulating material has a guide path for guiding the dropped molten metal melt further guided to the lower part of the molten metal leak receiving tray at a position where the molten metal melt guided by the lower guiding member falls. In this way, the saucer-filling heat insulating material has a guiding path, so that sufficient heat-insulating material is arranged at the bottom of the main chamber to prevent heat loss, but the leaked melt passes through the guiding path of the saucer-filling heat insulating material. It can be led to the lower part in the leaking pan. Thereby, since the molten metal leaking melt can be absorbed by the saucer-filling heat insulating material without solidifying the melt in the middle, the safety of the CZ method single crystal growing apparatus can be ensured.

  The saucer-filling heat insulating material is a heat insulating material that can absorb the molten metal leaked from the crucible, and a material made of low-density carbon fibers is preferable. Moreover, in this invention, the volume of a saucer filling heat insulating material shall be more than the maximum capacity | capacitance of the raw material melt accommodated in the said crucible. As a result, safety is ensured even when the crucible is deteriorated or the single crystal being pulled is dropped due to an earthquake or the like, and the crucible is destroyed and almost all the raw material melt flows out.

  The maximum capacity is determined by the diameter and height of the crucible provided in the apparatus, and is the maximum volume of the raw material melt that can be filled in the used crucible. This is usually the initial charge amount, which is the amount of raw material that is initially filled in the crucible.

  Moreover, it is preferable that the guide path of a saucer filling heat insulating material is a through-hole which penetrates a saucer filling heat insulating material to a perpendicular direction. The through-hole 16a of such a saucer-filling heat insulating material is the simplest guide path in which the saucer-filling heat insulating material 16 is not disposed in a portion where the melt falls, and the molten metal leaking melt 17 passes through the through-hole 16a. It becomes possible to reach the lowermost end of the hot water receiving tray 8 (FIGS. 1 and 2).

(Carbon cylinder)
Further, in the present invention, a carbon material cylinder is provided in the through hole of the saucer-filling heat insulating material, and the carbon material cylinder passes through the carbon material cylinder and the melt led to the lower part of the leaking saucer is the carbon material cylinder. It is preferable that it is what is arrange | positioned in the through-hole of the said saucer filling heat insulating material so that it can flow out of a cylinder at the lower end part.

Depending on the situation of the hot water leak, it is possible that the hot melt melt is absorbed by the saucer filling heat insulating material in the middle of the through hole of the saucer filling heat insulating material and cannot reach the bottom of the hot water saucer. It is more desirable to install a carbon material cylinder made of a carbon material in the through hole of the saucer-filling heat insulating material and allow the melt to pass therethrough. However, if the lower end of the carbon cylinder is left in contact with the bottom of the leaking tray, there is no path for the melt that has passed through the barrel to flow out of the cylinder, and the tray filling insulation absorbs the leaked melt. Therefore, the carbon material cylinder is arranged so that the melt guided to the lower part of the hot water leak tray through the carbon material cylinder can flow out of the cylinder at the lower end of the carbon material cylinder. For example, as a method of holding such a carbon material cylinder, a foot 18a ₁ is provided at the lower end of the carbon material cylinder 18a as in the form of the carbon material cylinder 18a on the left side of FIG. 6, or the carbon material cylinder on the right side of FIG. It is preferable to form a hole etc. like the form of 18d, and to install in a leaking saucer. Alternatively, as in the form of the carbon material cylinder 18b on the right side of FIG. 6, the carbon material cylinder 18b is floated and held from the lower end by the saucer-filling heat insulating material 16 filled therein instead of the hot water leaking saucer 8, and the carbon material cylinder It is also possible to hold the lower end portion of 18b away from the hot water leak receiving tray 8. Thereby, it becomes a single crystal growth apparatus with which safety was ensured more.

  Moreover, it is preferable that the said carbon material cylinder has a straight body part by which the several hole was opened in the side surface like FIG. In the unlikely event that the molten metal melts down to the temperature of the molten metal leaking tray, it is lowered to a temperature at which it is solidified, and the possibility of blocking the lower end of the carbon material cylinder disposed in the through hole of the tray filled heat insulating material is not zero. In order to prevent this, if a plurality of holes are formed in the straight body portions of the carbon material cylinders 18c and 18d as shown in FIG. 7, the melt can flow out to the heat insulating material side through the holes. Thereby, it becomes a single crystal growth apparatus with which safety was ensured more.

  Moreover, it is preferable that the saucer filling heat insulating material can be divided into a plurality of heat insulating materials. By dividing it into a plurality of parts, it is not necessary to integrally mold it in accordance with a complicated shape of the leaking tray, so that it is possible to reduce the molding cost of the heat insulating material. In addition, when a hot water leak actually occurs, it is necessary to replace the saucer-filled heat insulating material that has absorbed the melt. However, if multiple saucer-filled heat insulating materials are used, replace only the portion where the melt has penetrated. Other parts can be used again, and this is also low cost. In addition, the individual weight is reduced by the division, and the effect of floating by the buoyancy of the melt induced below can be expected. The amount of hot water leakage can be reliably ensured by floating the tray filling heat insulating material.

  Needless to say, it is safer to detect a hot water leak and deal with it as soon as possible, even when a hot water leak pan and a received amount of the hot water leak are prepared as described above. Therefore, it is more preferable to equip a sensor capable of detecting hot water leakage, such as a temperature sensor, directly under the guide path provided in the tray filling heat insulating material. In the present invention, since the melt guided by the guide path is detected, it is possible to detect the occurrence of molten metal leak quickly and with high accuracy.

  EXAMPLES Hereinafter, although the Example and comparative example of this invention are given and demonstrated further in detail, this invention is not limited to the following Example.

(Example)
As shown in FIG. 1, a single crystal growing apparatus provided with a lower induction member and a hot-water leaking tray having a tray-filling heat insulating material made of carbon fiber was prepared. Here, the lower guide member is a heat insulating plate, and the heat insulating plate guide structure has the same shape as shown in FIGS. 1 and 4 by providing a notch in a part of the guide wall provided on the outer peripheral portion. The saucer-filling heat insulating material has a volume equal to or greater than the maximum capacity of the raw material melt contained in the crucible, and the molten metal leaked in the lower part of the notch where the molten metal melt guided by the lower guiding member falls. A guide path for guiding the liquid further to the lower part of the hot water receiving tray was provided. Furthermore, the tray filling heat insulating material is the same as the carbon material tube 18b shown schematically on the right side of FIG. In addition, the tray filling heat insulating material was 15 cm in thickness, and the one having the most standard bulk density of 0.13 to 0.16 g / cm ³ was used.

  A 200 kg raw material melt was placed in a 65 cm diameter crucible in a hot zone (HZ) in this single crystal growing apparatus, and a silicon single crystal having a diameter of 20 cm was grown by a magnetic field application Czochralski method (MCZ method). More specifically, after the seed crystal is immersed in the raw material melt in the crucible, the crucible that can be moved up and down in the direction of the crystal growth axis is crystallized during crystal growth while pulling up the rod-shaped single crystal from the melt. The temperature was raised so as to compensate for the lowering of the liquid level, and the height of the melt surface was kept constant. The volume of the saucer filled heat insulating material at this time was 1.2 times the volume of 200 kg of silicon solid.

(Comparative example)
As shown in FIG. 3, a single crystal growing apparatus provided with a heat insulating plate and a hot water leak tray was prepared. Here, it is assumed that the heat insulating plate does not have a guide structure, and the hot water leaking tray has a flat tray inner wall heat insulating material disposed on the inner wall, and does not have a tray filling heat insulating material. The thickness of the inner wall heat insulating material of the tray was about 2 to 3 cm.

  A hot zone (HZ) in this single crystal growing apparatus was equipped with a crucible having a diameter of 65 cm, and a silicon single crystal having a diameter of 20 cm was grown by a magnetic field application Czochralski method (MCZ method) in the same manner as in the example.

  Although the single crystal growth apparatus of the example and the single crystal growth apparatus of the comparative example were able to grow crystals without problems, the comparative example had a large heat loss from the hot water receiving tray because there was no tray filling heat insulating material. Compared to this, in the example, since the heat loss from the hot water leaking tray can be prevented by the tray filling heat insulating material having a volume equal to or larger than the maximum capacity of the raw material melt contained in the crucible, the heat loss is small, and the result As a result, it was possible to achieve about 8% power saving as compared with the comparative example. Further, in the embodiment, the lower guiding member having a guiding structure for guiding the molten metal to be melted and dropped to the molten metal tray, and a volume equal to or larger than the maximum capacity of the raw material melt stored in the crucible, It is possible to avoid a situation in which the melt is solidified in the middle of the tray filling heat insulating material, so that the molten metal leaks. It was shown that it becomes a single crystal growth apparatus that can secure the capacity.

  Here, silicon crystal growth has been described as an example, but the present invention is not limited to a single crystal growth apparatus used for manufacturing a silicon single crystal, and a CZ method such as a compound semiconductor or an oxide single crystal is used. It can be applied to a single crystal growth apparatus. In addition, the present invention is characterized in that a heat insulating plate guiding structure and a guide path for the saucer filling heat insulating material are provided, the gist of which is to guide the molten metal melt to the bottom of the hot water saucer, and from the lower saucer filling heat insulating material. As long as it has this concept, various modifications and applications are naturally possible.

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

DESCRIPTION OF SYMBOLS 1,1 '... Single crystal growth apparatus, 2 ... Main chamber, 3 ... Crucible, 3a ... Quartz crucible, 3b ... Graphite crucible, 4 ... Thermal insulation plate, 4a ... Induction wall, 4b ... Induction wall break, 4c ... Taper shape 4d ... through hole of heat insulating plate, 5 ... raw material melt, 6 ... heater, 7 ... heater heat insulating material, 8 ... hot water leak tray, 10 ... crucible holding shaft, 11 ... sensor for detecting hot water leak, 12 ... single silicon Crystal, 13 ... Seed crystal, 14 ... Seed chuck, 15 ... Wire, 16 ... Sauce filling heat insulating material, 16a ... Induction path of saucer filling heat insulating material, 17 ... Hot water leaking melt, 18a, 18b, 18c, 18d ... Carbon material Cylinder, 18a ₁ ... Leg, 101 ... Single crystal growing apparatus, 102 ... Main chamber, 103 ... Crucible, 103a ... Quartz crucible, 103b ... Graphite crucible, 104 ... Insulating plate, 105 ... Raw material melt, DESCRIPTION OF SYMBOLS 106 ... Heater, 107 ... Heater insulation material, 108 ... Hot-water leaking tray, 109 ... Heat insulation material in a saucer inner wall, 110 ... Crucible holding shaft, 112 ... Silicon single crystal, 113 ... Silicon seed crystal, 114 ... Seed chuck, 115 ... Wire

Claims (8)

A main chamber for storing a crucible for storing the raw material melt and a heater for heating the raw material melt, and a hot water leak tray made of a carbon material which is installed at the bottom of the main chamber and stores the melt leaked from the crucible. A single crystal growing apparatus for growing a single crystal ingot by the Czochralski method comprising:
A lower guide member installed between the crucible and the hot water leak tray, having a guiding structure for guiding the hot water leaked melt leaked from the crucible and dropping it to the hot water leak tray,
The hot water leak tray has a tray filling heat insulating material made of carbon fiber filled in the space in the hot water leak tray,
The volume of the saucer filled heat insulating material is not less than the maximum capacity of the raw material melt accommodated in the crucible,
The tray filling heat insulating material has a guide path for guiding the dropped molten metal melt further guided to the lower part of the molten metal leak receiving tray at a position where the molten metal melt guided by the lower guiding member falls. An apparatus for growing a single crystal characterized by being.   The single crystal growing apparatus according to claim 1, wherein the guide path of the tray filling heat insulating material is a through-hole penetrating the tray filling heat insulating material in a vertical direction.   A carbon material cylinder is provided in the through hole of the tray filling heat insulating material, and the carbon material cylinder passes through the carbon material cylinder and the melt guided to the lower part of the hot water leakage tray is the lower end of the carbon material cylinder. The single crystal growing apparatus according to claim 2, wherein the single crystal growing apparatus is arranged in a through-hole of the tray-filling heat insulating material so that the portion can flow out of the cylinder.   The single-crystal growing apparatus according to claim 3, wherein the carbon material tube has a straight body portion having a plurality of holes formed on a side surface.   The single crystal growing apparatus according to any one of claims 1 to 4, wherein the tray filling heat insulating material can be divided into a plurality of heat insulating materials.   The single crystal growth apparatus according to any one of claims 1 to 5, wherein the lower induction member is configured by at least one of a heat insulating plate and a lower heater.   The heat insulating plate has a plate-shaped carbon material on at least the crucible surface side of the plate-shaped heat insulating material made of carbon fiber, and the plate-shaped carbon material has a guide wall or a tapered shape as a guide structure. The single crystal growing apparatus according to claim 6. The single crystal growing apparatus according to any one of claims 1 to 7, wherein the hot water leaking tray has a sensor that detects hot water leakage immediately below the guide path of the tray filling heat insulating material.

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