JP5488545B2 - 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 heat insulating material 109 is included.

  Further, as shown in FIG. 4, as another example, a single crystal growing apparatus 101 'having a thick heat insulating material 109' for absorbing the molten metal 117 is also used for manufacturing a semiconductor silicon single crystal rod. The single crystal growing apparatus 101 ′ having such a thick heat insulating material 109 ′ can prevent a heat loss from the hot water receiving tray as compared with the single crystal growing apparatus 101 of FIG.

  Next, a single crystal growth method using the above-described single crystal growth apparatuses 101 and 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. In this case, since the melt does not reach the heat insulating material below the portion where the melt is solidified, an area 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 such a viewpoint, Patent Document 6 discloses a technique for detecting a hot water leak by introducing a sensor for detecting the 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 is provided at the bottom of the main chamber to prevent heat loss and to obtain an energy saving effect, and the leaked melt is insulated. CZ method single crystal growth that can ensure the safety because it can be absorbed by the saucer-filling heat insulating material through the gap between the saucer-filling heat insulating materials without solidifying while remaining on the surface of the material An object is to provide an apparatus.

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 producing a single crystal ingot by the Czochralski method comprising a hot water leak receiving pan,
The hot water leak tray has a plurality of tray filling heat insulating materials filled in the hot water leak tray,
The filling volume occupied by the saucer filling heat insulating material is not less than the maximum capacity of the raw material melt accommodated in the crucible,
The single crystal growing apparatus is characterized in that at least the tray filling heat insulating material in the vicinity where the molten metal melt falls is a spherical shape or a polyhedral shape having a diameter of 1 cm to 10 cm.

  If such a saucer-filling heat insulating material is arranged in the vicinity where the molten metal melt falls, the surface is not flat and there is a gap between the saucer-filled heat insulating materials. Without being solidified while accumulating on the surface of the heat insulating material, it flows downward through the gap between the heat sinks filled with the saucer and can be absorbed by the heat sink filled with the saucer at the bottom. Can be secured. In addition, the weight of each saucer filling insulation is reduced by the division, and the effect of floating by the buoyancy of the melt induced below can also be expected. can do. Thereby, it becomes the CZ method single crystal growth apparatus which can reduce a heat loss with a saucer filling heat insulating material and can aim at power saving with the safe state which ensured the hot water leak capacity enough.

  Moreover, if such a saucer filling heat insulating material is used, since it is not necessary to shape | mold according to the shape of a complicated-shaped leaking water saucer, the shaping | molding cost of a saucer filling heat insulating material can also be suppressed extremely cheaply. In addition, when the heat sink leaks and the pan-filling insulation that has absorbed the melt is replaced, only the one that has penetrated the melt can be replaced, and the others can be reused. In this respect, the cost can be reduced.

  Moreover, it is preferable that the said hot water leak tray has a sensor which detects a hot water leak.

  As a result, it is possible to surely find the molten metal melt that reaches the bottom of the molten metal receiving tray, and the single crystal growing apparatus that ensures more safety.

  Furthermore, it is preferable to have a lower guide member for guiding the molten metal leaked from the crucible to the position of the sensor between the crucible and the sensor.

  Thereby, it becomes a single crystal growth apparatus which can detect the hot water leak by the sensor which introduces the hot water melt into the bottom of the hot water tray and detects the hot water leak more reliably and quickly.

  Moreover, it is preferable that the saucer filling heat insulating material of the vicinity where the said hot-water leaking melt falls is a spherical shape or a polyhedron shape whose diameter is 1 cm or more and 5 cm or less.

  If the size of a saucer filling heat insulating material is 5 cm or less, the clearance gap formed between saucer filling heat insulating materials will not become large too much, and it is excellent in the heat insulation effect. Also, if the size of the saucer-filling heat insulating material is 1 cm or more, the number of the saucer-filling heat insulating materials becomes too large, and it becomes difficult to distinguish from foreign substances such as dust, so that a situation that causes a problem of contamination can be avoided. .

  As described above, in the single crystal growth apparatus of the present invention, the surface of the saucer filling heat insulating material is not flat, and there is a gap between the saucer filling heat insulating materials. It can flow down through the gap between the saucer-filling heat insulating materials without solidifying while remaining on the surface of the tray, and can be absorbed from the saucer-filling heat insulating material at the bottom, ensuring a hot water leak acceptance amount be able to. In addition, the weight of the individual saucer filling insulation is reduced by the division, and the effect of floating by the buoyancy of the molten metal leaked below can also be expected. be able to. Thereby, it becomes the CZ method single crystal growth apparatus which can reduce a heat loss with a saucer filling heat insulating material and can aim at power saving with the safe state which ensured the hot water leak capacity enough.

  Moreover, if such a saucer filling heat insulating material is used, since it is not necessary to shape | mold according to the hot water leaking saucer of a complicated shape, it also becomes possible to hold down the shaping | molding cost of a saucer filling heat insulating material cheaply. In addition, when the heat sink leaks and the pan-filling insulation that has absorbed the melt is replaced, only the one that has penetrated the melt can be replaced, and the others can be reused. In this respect, the cost can be reduced.

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 the other example of the conventional CZ method single crystal growth apparatus.

  Hereinafter, the present invention will be described in more detail, but the present invention is not limited thereto. As described above, there has been a demand for a CZ method single crystal growing apparatus that can prevent heat loss, obtain an energy saving effect, and can ensure safety. First, experimental examples for conceiving the present invention will be described.

(Experimental example 1: integrated heat insulating material)
A simple furnace imitating the Czochralski method, equipped with a heater and 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 in the crucible so that a hot water leak occurred when the raw material melted. Further, as shown in FIG. 4, an integrated heat insulating material 109 ′ made of carbon fiber is disposed under the crucible 103 in an isotropic graphite hot water receiving tray 108 on the lower side of the furnace. . At this time, the thickness of the heat insulating material was 10 cm. Carbon fiber insulation materials with a bulk density of 0.1 to 1.0 g / cm ³ are available, but the most standard one is 0.13 to 0.16 g / cm ³ . In Examples and Comparative Examples described later, carbon fiber heat insulating materials having a bulk density of 0.13 to 0.16 g / cm ³ were used.

  Electric power was supplied to the heater to start heating. After confirming that a part of the silicon raw material contained in the crucible started to dissolve, about 5 minutes passed, the battery was turned off and cooled. After the inside of the furnace was cooled, the integrated heat insulating material was taken out and observed. As a result, silicon penetrated from the surface of the heat insulating material to a thickness of several centimeters, and there was no penetration of silicon from there. In addition, hardened silicon was raised on the surface of the heat insulating material.

  From the above, if the water leaks little by little, silicon is solidified near the surface of the integrated heat insulating material, and silicon that cannot be absorbed remains on the surface of the integrated heat insulating material. did it. Therefore, if this state continues and a large amount of hot water leaks, only the upper part of the integrated heat insulating material will function as a hot water receiver, and hot water may overflow from the hot water tray. It was.

(Experimental example 2: divided heat insulating material)
Except that instead of the integrated heat insulating material, the inside of the hot water leaking saucer was filled with a roughly spherical carbon fiber saucer filling heat insulating material having a diameter of about 3 cm, and the height was about 10 cm. Conducted the same test as in Experimental Example 1. When the tray filling heat insulating material in the furnace was observed after turning off, the melt flowing through the gap between the tray filling heat insulating material reached the bottom of the leaking tray.

  For this reason, by using a plurality of saucer-filling heat insulating materials having a substantially spherical shape, it is possible to avoid a situation in which melt accumulates on the surface of the saucer-filling heat insulating material in the hot water leaking tray and does not work as a hot water leakage acceptance amount. It became clear that

  When the present inventors examined the above results, the basin having a diameter of not less than 1 cm and not more than 10 cm at least in the vicinity of the molten metal leaking in the molten metal receiving tray is not integrated into the tray filled heat insulating material. If it is a single crystal growth apparatus equipped with a hot water leaking tray that is filled with a plurality of shape or polyhedron-shaped tray filling heat insulating materials and the filling volume is equal to or greater than the maximum capacity of the raw material melt contained in the crucible, the tray filling heat insulation The present invention was completed by finding a single crystal growth apparatus that can prevent heat loss with a material, obtain an energy saving effect, and can also ensure safety when a hot water leak occurs. This will be described in more detail below.

[Single crystal growth equipment]
The present invention includes a main chamber that stores a crucible for storing a raw material melt and a heater for heating the raw material melt, and a carbon material that is installed at the bottom of the main chamber and stores a melt leaked from the crucible. A single crystal growing apparatus for producing a single crystal ingot by the Czochralski method comprising a hot water leak receiving pan,
The hot water leak tray has a plurality of tray filling heat insulating materials filled in the hot water leak tray,
The filling volume occupied by the saucer filling heat insulating material is not less than the maximum capacity of the raw material melt accommodated in the crucible,
Of the tray filling heat insulating material, at least the tray filling heat insulating material in the vicinity where the molten metal melt falls is a spherical or polyhedral shape having a diameter of 1 cm or more and 10 cm or less.

  FIG. 1 shows a first embodiment of the CZ method single crystal growing apparatus of the present invention. A single crystal growing apparatus 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 apparatus 1, a heat insulating plate 4 is mainly installed to prevent heat loss.

  As shown in FIG. 1, when the heat sink 16 in the vicinity 16a where the molten metal falls falls into a spherical shape or a polyhedral shape, when the molten metal leaks, it drops onto the heat insulating plate 4 and further flows into the hot water. The melt 17 falling on the leak receiving tray 8 passes through the gap of the receiving tray filling heat insulating material 16, falls on the bottom of the hot water leak receiving tray 8 disposed on 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 leaking saucer 8.

  Since the surface filled with the saucer-filling heat insulating material 16 is not flat and there are many gaps between the saucer-filling heat insulating materials 16, the melt immediately flows downward and solidifies while remaining on the surface of the heat insulating material. Such a situation can be avoided, and the melt can reach the bottom of the leaking pan. As a result, it is possible to expect the entire filling volume of the tray filling heat insulating material 16 as the hot water leakage volume. Thereby, it becomes the CZ method single crystal growth apparatus 1 which can reduce a heat loss and can aim at power saving with the safe state which ensured enough hot water leak capacity.

  In addition, although the case where the heat insulation board 4 was mounted | worn under the crucible was described in FIG. 1, a heat insulation board is not necessarily required in this invention, and the lower heater may be installed instead of the heat insulation board 4. 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. Further, in order to detect the hot water leak more reliably and early, a lower guide member for guiding the hot water melt 17 leaked from the crucible 3 to the position of the sensor 11 is provided between the crucible 3 and the sensor 11. preferable. Here, as shown in FIG. 2 as the CZ method single crystal growth apparatus 1 ′ according to the second embodiment of the present invention, the lower induction member includes a heat insulating plate 4 having an induction structure 4a, a lower heater having an induction structure, and a saucer. It can be set as the cylinder 18 which can be provided in a 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, a thin plate-shaped tray inner wall heat insulating material can also be arrange | positioned to the inner wall of a hot water leak tray. Hereinafter, the present invention will be described in more detail.

[Insulation material for saucer filling]
The single crystal growing apparatus of the present invention has a plurality of saucer-filling heat insulating materials filled in a leaking saucer. The filling volume occupied by the saucer filling heat insulating material is equal to or greater than the maximum capacity of the raw material melt accommodated in the crucible, and at least the saucer filling heat insulating material in the vicinity where the molten metal melt falls is 1 cm in diameter. It is a spherical shape or a polyhedral shape that is 10 cm or less.

  In the case of a heat insulating material that has an integrated pan-filling heat insulating material and has a flat surface, when the hot water leaks gradually, the melt is solidified near the surface and reaches the lower side. do not do. However, in the case of a plurality of saucers filled with a spherical shape or polyhedron shape, the surface is not flat and there are many gaps between the saucer filled insulators, so the melt quickly flows downward. It does not solidify while remaining on the surface. Therefore, it is possible to secure a sufficient amount of molten metal leak by arranging such a saucer-filled heat insulating material at least in the vicinity of the molten metal leaking melt. Of course, a saucer-filling heat insulating material of this shape may be disposed over the entire leaking saucer.

  In addition, if the hot water leaking tray is filled with a plurality of such spherical or polyhedral tray filling heat insulating materials, there is no need to mold according to the shape of the complicated shape of the hot water leakage receiving pan. The molding cost can be kept low.

  Furthermore, when a hot water leak actually occurs, it is necessary to replace the tray filling heat insulating material that has absorbed the melt. Of course, if the entire amount leaks, it will be completely replaced, but in general, it is usually settled with a small amount of leak. In such a case, it is possible to replace only the saucer-filled heat insulating material that has penetrated the melt in the vicinity where the molten metal melt falls, and the other parts can be reused. Can be kept cheap.

  In addition, by dividing into a spherical shape or a polyhedral shape having a diameter of 1 cm or more and 10 cm or less, the weight of each saucer filling heat insulating material is reduced, and the effect that the saucer filling heat insulating material floats by the buoyancy of the melt that has permeated below. I can expect. Thus, the amount of hot water leakage can be reliably ensured by floating the tray filling heat insulating material. Since the spherical and polyhedral heat insulating materials have a large surface area, they can immediately absorb the melt.

  When the size of the saucer-filling heat insulating material is larger than 10 cm in diameter, the gap formed between the saucer-filling heat insulating materials becomes large, so that the heat insulation effect is reduced and heat loss is generated, and the energy saving effect cannot be obtained. On the other hand, when the size of the saucer filling insulation is smaller than 1 cm in diameter, the number of the saucer filling insulation filled in the leaking saucer is too large, and it is difficult to distinguish from foreign substances such as dust, May cause contamination problems. For this reason, the spherical or polyhedral saucer filled heat insulating material of the present invention has a diameter of 1 cm or more and 10 cm or less. The diameter of the polyhedron shape means the diameter of a sphere circumscribing the polyhedron shape.

  Here, the shape and size of the saucer-filling heat insulating material to be used are other than that if a spherical or polyhedral-shaped saucer-filling heat insulating material having a diameter of 1 cm or more and 10 cm or less is used at least in the vicinity where the molten metal melt falls All of the portions may be the same in the leaking pan, or different shapes and sizes may be mixed. For example, the tray filling heat insulating material in the vicinity where the molten metal melt falls is a plurality of tray filled heat insulating materials having a diameter of 1 cm or more and 10 cm or less. It is also possible to form with a material.

  A more preferable shape and size of the saucer-filling heat insulating material is a spherical or polyhedral saucer-filling heat insulating material having a diameter of 1 cm to 5 cm. A schematic diagram is shown in FIGS. If it is a spherical shape or a polyhedral shape, there is almost no possibility that the portion where the molten metal melt falls is a flat plane, and the melt is easily introduced into the bottom of the molten metal tray. Moreover, if the size of a saucer filling heat insulating material is diameter 1 cm or more and 5 cm or less, since the clearance gap formed by heat insulating materials will become small, the heat insulation effect can be anticipated and handling is easy. In the cleaning operation of the single crystal growing apparatus performed after the single crystal growth, a work procedure such as removing the tray filling heat insulating material once and returning it again can be considered, but in such a case, the diameter should be 1 cm or more and 5 cm or less. For example, a commercially available vacuum cleaner or the like is used to collect the tray filling heat insulating material, and when returning, the collected tray filling heat insulating material can be spread as it is, so that maintenance is facilitated.

  Moreover, the saucer-filling heat insulating material is a heat insulating material that can absorb the molten metal leaked from the crucible, and is preferably made of a low-density carbon fiber. Furthermore, in the present invention, the filling volume occupied by the tray filling heat insulating material is set to be equal to or larger than the maximum capacity of the raw material melt accommodated in the 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. The filling volume refers to the sum of the volume of the tray filling heat insulating material itself and the volume occupied by the gap between the tray filling heat insulating materials.

[Sensor for detecting leaks]
It is preferable that the said hot water leak tray has a sensor which detects a hot water leak. With the shape and size of the saucer-filled heat insulating material as described above, the melt can reach the bottom of the leaking saucer as soon as a leak occurs. Therefore, as shown in FIGS. 1 and 2, it is possible to detect a hot water leak at an early stage by installing the sensor 11 for detecting the hot water leak in the hot water tray 8. Can be implemented early.

[Lower induction member]
It is preferable to have a lower guide member for guiding the molten metal leaked from the crucible to the position of the sensor between the crucible and the sensor. In order to ensure early detection and early countermeasures for the above-described hot water leak, the melt is detected when a hot water leak occurs between the crucible containing the raw material melt and the sensor that detects the hot water leak. It is preferable to provide a lower guide member that forms a passing path. As an example, in FIG. 2, a guiding structure 4 a is provided on a heat insulating plate 4 arranged mainly for the purpose of reducing heat loss under the crucible 3, and a desired one on the heat insulating plate 4 is used as one of lower guiding members. A form in which the melt is dropped from the position and a cylindrical lower guide member (cylinder 18) is provided also in the tray filling heat insulating material 16 in the hot water leakage tray 8 is shown. The lower end portion of the cylindrical lower guide member (cylinder 18) is adapted to allow the molten metal to flow out. According to such a form, it becomes a single crystal growing apparatus that can introduce the molten metal melt into the bottom of the molten metal receiving tray more reliably and more quickly and can detect the molten metal leak by the sensor that detects the molten metal.

  Even in the case where there is such a lower guide member, if a plurality of tray filling heat insulating materials are arranged in the vicinity where the molten metal melt falls, only the portion that has absorbed the molten metal when a molten metal leak actually occurs Exchange is possible, and the replacement cost can be reduced.

  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 hot water leaking saucer filled with a spherical saucer filling heat insulating material having a diameter of 3 cm was prepared. The filling volume of the saucer-filling heat insulating material is assumed to have a volume equal to or greater than the maximum capacity of the raw material melt contained in the crucible, and in this embodiment, the height at which the saucer-filling heat insulating material is stacked is set to approximately 15 cm. Moreover, as a saucer filling heat insulating material, the thing with the most standard bulk density of 0.13-0.16 g / cm < ³ > was used.

  In the main chamber of this single crystal growing apparatus, 200 kg of raw material melt was accommodated in a 65 cm diameter crucible, 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 filling volume of the saucer-filling heat insulating material at this time was 1.2 times the volume of 200 kg of silicon solid.

(Comparative Example 1)
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, the hot-water leaking tray has a planar heat insulating material disposed on the inner wall, and does not have a spherical or polyhedral tray-filling heat insulating material. The thickness of the planar heat insulating material was about 2 to 3 cm.

  A crucible with a diameter of 65 cm was installed in the main chamber of this single crystal growth apparatus, and a silicon single crystal with a diameter of 20 cm was grown by a magnetic field application Czochralski method (MCZ method) in the same manner as in the example.

(Comparative Example 2)
As shown in FIG. 4, a single crystal growing apparatus having the same configuration as that of Comparative Example 1 was prepared except that the hot water leaking tray had an integrated heat insulating material having a thickness of 15 cm. A silicon single crystal was grown using this as in the example.

  Although the single crystal growing apparatus of the example and the single crystal growing apparatuses of Comparative Examples 1 and 2 were able to grow crystals without any problem, in Comparative Example 1, there was no thick saucer filled heat insulating material, so heat loss from the leaking saucer Was big. In comparison with this, in the example, since the heat loss from the hot water receiving pan can be prevented by the pan filling heat insulating material having a filling volume equal to or larger than the maximum capacity of the raw material melt accommodated in the crucible. As a result, power saving of about 8% was achieved.

  Further, in Comparative Example 2, the energy saving effect was similar to that of the Example, but as shown in Experimental Example 1, when this one-piece type heat insulating material was used, The hot water leakage capacity may be insufficient. In contrast to this, in the embodiment of the present invention, even if a hot water leak occurs, the melt can reach the bottom of the hot water receiving tray, and a sufficient amount of the hot water leak can be secured, thus ensuring safety. Single crystal growing apparatus. Furthermore, when the comparative example 2 is compared with the examples, the embodiment of the present invention is advantageous in terms of the molding cost of the saucer-filling heat insulating material and the replacement cost of the saucer-filling heat insulating material in the event of a leakage of hot water.

  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.

  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 board, 4a ... Induction structure, 5 ... Raw material melt, 6 ... Heater, 7 DESCRIPTION OF SYMBOLS ... Heater insulation material, 8 ... Hot water leak tray, 10 ... Crucible holding shaft, 11 ... Sensor detecting hot water leak, 12 ... Silicon single crystal, 13 ... Seed crystal, 14 ... Seed chuck, 15 ... Wire, 16 ... Filling tray Insulating material, 16a: in the vicinity where the molten metal leaks, 17 ... molten metal in the molten metal, 18 ... cylinder, 101, 101 '... single crystal growing apparatus, 102 ... main chamber, 103 ... crucible, 103a ... quartz crucible, 103b DESCRIPTION OF SYMBOLS ... Graphite crucible, 104 ... Heat insulation board, 105 ... Raw material melt, 106 ... Heater, 107 ... Heater insulation material, 108 ... Hot water leak tray, 109, 109 '... Heat insulation material, 110 ... Lu Bo holding shaft, 112 ... silicon single crystal, 113 ... silicon seed crystal, 114 ... seed chuck, 115 ... wire, 117 ... water leakage melt

Claims (4)

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 producing a single crystal ingot by the Czochralski method comprising:
The hot water leak tray has a plurality of tray filling heat insulating materials filled in the hot water leak tray,
The filling volume occupied by the saucer filling heat insulating material is not less than the maximum capacity of the raw material melt accommodated in the crucible,
The single crystal growing apparatus characterized in that at least the tray filling heat insulating material in the vicinity where the molten metal melt falls out of the tray filling heat insulating material has a spherical shape or a polyhedral shape with a diameter of 1 cm to 10 cm.   The single crystal growing apparatus according to claim 1, wherein the hot water leak tray has a sensor for detecting hot water leak.   The single crystal growing apparatus according to claim 2, further comprising a lower guide member that guides the molten metal leaked from the crucible to the position of the sensor between the crucible and the sensor. The single-piece | unit of any one of Claims 1 thru | or 3 characterized by the above-mentioned. Crystal growth device.

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