JP2015040146A - Single crystal production device and single crystal production method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a single crystal production device capable of obtaining a high-quality long single crystal, and a single crystal production method using the same.SOLUTION: A single crystal production device according to the present invention comprises: a crucible 1 for housing a raw material 2 of a single crystal; a crucible lid 3 covering an upper face of the crucible 1 and having an opening at a center; a pedestal 5 provided in the crucible 1 with a back face exposed from the opening of the crucible lid 3, and fixing a seed crystal 4s; a guide 6 provided on an inner wall of the crucible 1 to cover a crystal growth region, and guiding raw material gas formed by sublimating the raw material 2 to the seed crystal 4s; and an upper lid 8 annularly provided on the crucible lid 3 except for the opening of the crucible lid 3, and forming a chamber between it and the crucible lid 3. A through hole 7 communicated with the chamber is provided on the crucible lid 3 around the pedestal 5.

Description

  The present invention relates to the manufacture of semiconductor single crystals.

  Silicon carbide (SiC) is known as a semiconductor material that has excellent thermal and chemical characteristics, has a forbidden band width larger than that of a silicon (Si) semiconductor, and has excellent characteristics. In particular, 4H-type silicon carbide has been put to practical use as a semiconductor material for power devices because of its high electron mobility and saturated electron velocity.

  An improved Rayleigh method (sublimation method) is widely used as a method for obtaining a semiconductor single crystal. Currently, substrates with a diameter of up to 100 mm are commercially available, and substrates with a diameter of 150 mm are also being commercialized. However, the crystal defect density is still high, and it is necessary to further reduce the crystal defect density for use as a semiconductor device.

  SiC single crystal by sublimation method is prepared by placing a seed crystal and a raw material facing each other in a crucible, heating the raw material to about 2300 ° C to sublimate, and recrystallizing the raw material gas generated by sublimation on the seed crystal. This is a method of growing a crystal. As a method for heating the crucible, induction heating by high frequency is generally used. Therefore, graphite is generally used as a material for the crucible because it is conductive and must be able to withstand at high temperatures. The crucible is generally cylindrical from the viewpoint of eliminating temperature non-uniformity due to the skin effect due to high frequency induction heating and facilitating processing. Furthermore, in order to suppress heat radiation from the crucible and heat efficiently, the crucible is covered with a heat insulating material. Since this heat insulating material is not conductive and needs to be able to withstand at a high temperature of 2400 ° C., a graphite heat insulating material is used.

  In order to reduce the cost of the SiC substrate, it is necessary to grow a long SiC ingot, and in order to use it for a semiconductor device, it is necessary to have a low defect density. In order to grow a low defect and long SiC ingot, various studies have been made and many reports have been made. For example, methods disclosed in Patent Documents 1 and 2 are disclosed.

Japanese Patent No. 3792699 JP 2011-105524 A

  In the methods shown in Patent Documents 1 and 2, the raw material gas is efficiently guided onto the pedestal using a guide in order to grow a high-quality single crystal. Thereby, the single crystal part grows independently and is integrated with the polycrystalline part. If the polycrystal is deposited on the inner wall of the guide, it will be integrated with the single crystal part and the quality of the single crystal part will deteriorate, so the temperature of the guide will be higher than the single crystal part and the source gas will be efficiently collected on the seed crystal, A device has been devised to prevent the precipitation of polycrystals on the inner wall of the guide.

  In particular, in the method disclosed in Patent Document 1, a raw material gas not related to single crystal growth is introduced into a chamber provided on the crucible lid, and the polycrystal is grown in the single crystal growth in the chamber. I try not to interfere.

  However, if the chamber is provided even on the pedestal, the heat radiation from the back surface of the pedestal is radiated in the chamber, resulting in a small temperature difference between the guide and the seed crystal. Therefore, there is a problem that crystal growth is not performed on the pedestal preferentially, polycrystals are deposited on the inner wall of the guide, and the quality of the single crystal is deteriorated.

  In view of the above-described problems, an object of the present invention is to provide a single crystal manufacturing apparatus for obtaining a high-quality and long single crystal, and a single crystal manufacturing method using the same.

  The single crystal production apparatus of the present invention is provided in a crucible containing a raw material for a single crystal, a crucible lid that covers the upper surface of the crucible and has an opening in the center, and the back surface is exposed from the opening of the crucible lid. A base for fixing the seed crystal, a guide provided on the inner wall of the crucible so as to surround the crystal growth region, a guide for guiding the source gas formed by sublimation of the raw material to the seed crystal, and opening the crucible lid on the crucible lid And an upper lid that forms a chamber with the crucible lid, and the crucible lid is provided with a through hole that communicates with the chamber around the pedestal.

  The single crystal production method of the present invention is a single crystal production method using the single crystal production apparatus of the present invention, wherein (a) a crucible of the single crystal production apparatus is filled with a raw material, and a seed crystal is placed on a pedestal. And (b) a step of sublimating the raw material for a predetermined time to grow a single crystal on the seed crystal.

  The single crystal production apparatus of the present invention is provided in a crucible containing a raw material for a single crystal, a crucible lid that covers the upper surface of the crucible and has an opening in the center, and the back surface is exposed from the opening of the crucible lid. A base for fixing the seed crystal, a guide provided on the inner wall of the crucible so as to surround the crystal growth region, a guide for guiding the source gas formed by sublimation of the raw material to the seed crystal, and opening the crucible lid on the crucible lid And an upper lid that forms a chamber with the crucible lid, and the crucible lid is provided with a through hole that communicates with the chamber around the pedestal. By adopting a structure in which the heat of the pedestal is released from the back surface to the outside of the chamber, a temperature difference is provided between the seed crystal and the guide, and precipitation of polycrystals on the inner wall of the guide is suppressed. Thereby, it is possible to obtain a high quality and long single crystal.

  The single crystal production method of the present invention is a single crystal production method using the single crystal production apparatus of the present invention, wherein (a) a crucible of the single crystal production apparatus is filled with a raw material, and a seed crystal is placed on a pedestal. And (b) a step of sublimating the raw material for a predetermined time to grow a single crystal on the seed crystal. The apparatus for producing a single crystal according to the present invention has a structure in which the heat of the pedestal is released from the back surface to the outside of the chamber, thereby providing a temperature difference between the seed crystal and the guide and suppressing the precipitation of the polycrystal on the inner wall of the guide . Thereby, it is possible to obtain a high quality and long single crystal.

1 is a sectional view of a single crystal manufacturing apparatus according to Embodiment 1. FIG. FIG. 3 is a diagram showing through holes formed in a crucible lid of the single crystal manufacturing apparatus according to Embodiment 1. FIG. 3 is a diagram showing through holes formed in a crucible lid of the single crystal manufacturing apparatus according to Embodiment 1. 6 is a cross-sectional view of a single crystal manufacturing apparatus according to Embodiment 2. FIG. It is sectional drawing of the single crystal manufacturing apparatus which concerns on Embodiment 2 at the time of the 1st time of single crystal regrowth. It is sectional drawing of the single crystal manufacturing apparatus which concerns on Embodiment 2 at the time of the 2nd time of single crystal regrowth.

<A. Embodiment 1>
<A-1. Configuration>
FIG. 1 is a cross-sectional view of single crystal manufacturing apparatus 100 according to the first embodiment.

  The single crystal manufacturing apparatus 100 includes a crucible 1, a crucible lid 3, a pedestal 5, a guide 6, a guide heat insulating material 10, an upper lid 8, and an upper lid heat insulating material 9. The shape of the crucible 1 is generally cylindrical from the viewpoint of eliminating temperature non-uniformity due to the skin effect due to high frequency induction heating and facilitating processing. The crucible lid 3 is a member that covers the upper surface of the crucible 1 and has an opening at the center of the upper surface. The pedestal 5 is a member for fixing the seed crystal 4 s and is attached to the crucible lid 3 with the back surface exposed from the opening of the crucible lid 3. For the seed crystal 4s, a 4H—SiC carbon surface having an off angle of 8 ° in the <11-20> direction is used, and its diameter is equal to the diameter of the pedestal 5 and is 65 mm.

  The crucible 1 is filled with the raw material 2, and the raw material 2 is sublimated by heating the crucible 1, and the single crystal is formed by recrystallizing the raw material gas on the seed crystal 4s.

  The guide 6 is attached to the inner wall of the crucible 1 or the inner wall of the crucible lid 3 so as to surround the growth region of the single crystal, and efficiently introduces the source gas sublimated from the source material 2 into the seed crystal 4s. Although FIG. 1 shows the tapered guide 6 whose inner diameter increases from the seed crystal 4s side to the raw material 2 side, the inner diameter may be constant from the seed crystal 4s side to the raw material 2 side.

  A guide heat insulating material 10 is provided between the guide 6 and the crucible 1 or the crucible lid 3.

  An upper lid 8 is provided in an annular shape on the upper part of the crucible lid 3 so as to avoid the opening of the crucible lid 3, and a chamber is formed by the crucible lid 3 and the upper lid 8. The outer diameter of the upper lid 8 is 180 mm, which is equal to the diameter of the crucible 1, and the inner diameter is 40 mm. In the crucible lid 3, a through hole 7 is provided in the vicinity of the pedestal 5, and the sublimation gas that has passed through the pedestal 5 is introduced into the chamber through the through hole 7. By providing the upper lid 8 while avoiding the opening of the crucible lid 3, the heat released from the back surface of the base 5 is not radiated in the chamber.

  An upper lid heat insulating material 9 is provided in the chamber. The upper lid heat insulating material 9 can effectively increase the temperature difference between the guide 6 and the pedestal 5, and can suppress the precipitation of polycrystals on the inner wall surface of the guide 6.

  For the crucible 1, the crucible lid 3, the guide 6, and the upper lid 8, for example, graphite is used because it is required to have conductivity and high temperature resistance of 2400 ° C. Further, the upper lid heat insulating material 9 and the guide heat insulating material 10 are made of graphite heat insulating material as a material having no electrical conductivity and having a high temperature resistance of 2400 ° C.

  However, when a graphite heat insulating material is used as the upper lid heat insulating material 9, since the reactivity with the raw material gas is high, carbon inclusions are formed in the crystal, which may deteriorate the crystal quality. For this reason, it is necessary to carefully determine the dimension of the through hole 7.

  Further, when a graphite heat insulating material is used for the guide heat insulating material 10, since the reactivity with the raw material gas is high and etching causes carbon inclusion in the single crystal, the raw material gas enters the guide heat insulating material 10. Make the structure unreachable.

  2 is a cross-sectional view taken along line AA of single crystal manufacturing apparatus 100 shown in FIG. The diameter of the through hole 7 is 2 mm, and as shown in FIG. 2, 16 through holes 7 are arranged on the outer periphery of the base 5 at equal intervals. Alternatively, a shape obtained by dividing a circle as shown in FIG. 3 may be used. The total area of the through holes 7 is 0.7% or more and less than 6.0% of the area of the base 5. If it is less than 0.7%, the source gas cannot be sufficiently introduced into the chamber, and polycrystals are deposited on the inner wall surface of the guide 6. On the other hand, if the content is 6.0% or more, the raw material gas is excessively discharged into the upper lid 8 and the raw material yield is greatly reduced. For this reason, it takes too much time to produce a long ingot. Furthermore, carbon inclusions generated by the reaction between the raw material gas and the upper lid 8 may flow backward from the gas flow and be taken into the crystal, thereby deteriorating the crystal quality.

  Although the growth rate varies depending on the structure of the furnace or crucible, a high-quality crystal with a low defect density can be obtained by determining the hole area and shape so that the growth rate is in the range of 0.08 to 0.25 mm / h. Can be easily obtained.

  When the polycrystal is deposited around the pedestal 5, a resistance is generated in the flow of the raw material gas to the upper lid 8, and the polycrystal is easily deposited on the inner wall surface of the guide 6. For this reason, it is necessary to design the single crystal manufacturing apparatus 100 so that the space around the base 5 is as small as possible.

Since the inner wall of the guide 6 and the inner wall of the upper lid 8 are exposed to the source gas, they are easily etched. However, when etched, the possibility of forming carbon inclusions in the crystal is very high. Therefore, from the viewpoint of preventing etching, high density graphite having a density of 1.9 g / cm ³ or more is preferably used for these graphite parts. Further, graphite coated with a refractory metal film such as TaC may be used, or a thin plate of a refractory metal such as Ta may be provided.

  In this embodiment, a Ta plate having a thickness of 50 μm is installed on the inner wall surface of the guide 6. However, if the Ta plate reacts with graphite during single crystal growth, it becomes a TaC plate and the size increases. When the outer peripheral length of TaC becomes larger than the inner peripheral length of the guide 6, the TaC bends toward the inner side of the guide and comes into contact with the single crystal to deteriorate its quality. For this reason, when arranging metals such as Ta on the inner wall of the guide, it is necessary to pay attention to the dimensions after carbonization. Moreover, when installing a metal coating or a metal, it is not necessary to use high density graphite for the guide 6.

<A-2. Manufacturing process>
Next, the manufacturing process of the SiC single crystal by the single crystal manufacturing apparatus 100 is shown.

First, the raw material 2 is filled in the single crystal manufacturing apparatus 100, and the seed crystal 4 s is attached to the pedestal 5. Then, a heat insulating material (not shown) is installed around the single crystal manufacturing apparatus 100 and disposed in the furnace, and the pressure in the furnace is evacuated to a level of 10 ⁻⁴ Pa. Thereafter, the furnace is filled with an inert gas, argon, and the pressure is maintained at 800 hPa. While maintaining the pressure, the bottom center temperature of the single crystal manufacturing apparatus 100 is increased to 2400 ° C. (measured with a pyrometer), which is the growth temperature of the SiC single crystal, by induction heating. Subsequently, while maintaining the temperature of the single crystal manufacturing apparatus 100, the pressure in the furnace is reduced to 3.3 hPa, which is the growth pressure of the SiC single crystal, and at that point, SiC single crystal growth starts.

  After performing the single crystal growth for 100 hours, the pressure in the furnace is returned to 800 hPa. Further, after the furnace temperature is lowered to room temperature over 24 hours, the single crystal manufacturing apparatus 100 is taken out from the furnace.

As a result of the above steps, no polycrystal was deposited on the inner wall of the guide 6, and only the single crystal portion grew independently. The obtained ingot was sliced at a thickness of about 1.5 mm in parallel with the seed crystal 4s using a wire saw, and the silicon surface of the wafer obtained from the vicinity of the upper portion of the ingot was ground, polished, and subjected to CMP processing. When rocking curve mapping measurement was performed using an X-ray diffraction method, the average of the rocking curve half-width of (0004) plane diffraction was 16.5 seconds, which was very high quality. Moreover, when the molten KOH etching process was performed to the same sample and the micropipe density was calculated | required, it was as low as 0.06 / cm < ² >. Since the single crystal part grew independently and the pressure from the polycrystal and the like could be prevented, it is considered that a high quality crystal could be obtained.

<A-3. Effect>
Single crystal manufacturing apparatus 100 according to Embodiment 1 includes crucible 1 that accommodates raw material 2, crucible cover 3 that covers the upper surface of crucible 1, an opening at the center, and the back surface exposed from the opening of crucible cover 3. A pedestal 5 provided in the crucible 1 for fixing the seed crystal 4s, a guide 6 provided on the inner wall of the crucible 1 so as to surround the crystal growth region, and a guide 6 for guiding the source gas formed by sublimation of the source material 2 to the seed crystal 4s The upper lid 8 is provided on the crucible lid 3 so as to avoid the opening of the crucible lid 3 and forms a chamber between the crucible lid 3 and the crucible lid 3. In addition, the crucible lid 3 is provided with a through hole 7 that communicates with the chamber around the pedestal 5. By providing the upper lid 8 in an annular shape, heat can be efficiently radiated from the back surface of the pedestal 5, so that the temperature difference between the guide and the single crystal portion can be increased. Therefore, a source gas that does not contribute to crystal growth can be efficiently introduced into the chamber. Therefore, precipitation of polycrystals on the inner wall of the guide 6 can be suppressed, and a long and high-quality single crystal with a low defect density can be manufactured. Further, by using the seed crystal 4s made of silicon carbide, a high-quality silicon carbide single crystal having a long and low defect density can be manufactured.

  If the area of the through hole 7 is 0.7% or more and less than 6.0% of the area of the pedestal 5, an appropriate amount of source gas can be introduced into the chamber while maintaining a constant source yield. A high-quality single crystal having a long and low defect density can be produced.

  In addition, the single crystal manufacturing apparatus 100 can effectively increase the temperature difference between the guide 6 and the pedestal 5 by providing the upper lid heat insulating material 9 in the chamber, and polycrystals are deposited on the inner wall surface of the guide 6. This can be further suppressed. Further, the same effect can be obtained by providing the guide heat insulating material 10 between the guide 6 and the inner wall of the crucible 1.

Further, by making the material of the guide 6 graphite having a density of 1.9 g / cm ³ or more, it is possible to suppress etching by the source gas and to suppress deterioration of the crystal quality due to carbon inclusion.

  In addition, the single crystal manufacturing apparatus 100 includes a guide inner wall member made of a refractory metal or a compound thereof disposed on an inner wall that is a surface of the guide 6 with respect to a crystal growth region, so that a raw material gas for the guide 6 made of graphite. It is possible to suppress etching due to carbon and to suppress deterioration in crystal quality due to carbon inclusion.

  In addition, the single crystal manufacturing method according to Embodiment 1 using the single crystal manufacturing apparatus 100 includes: (a) the step of filling the crucible 1 of the single crystal manufacturing apparatus 100 with the raw material 2 and attaching the seed crystal 4s to the pedestal 5; And (b) a step of sublimating the raw material 2 for a predetermined time to grow the single crystal 4 on the seed crystal 4s. Thereby, a high quality single crystal having a long and low defect density can be manufactured.

  Moreover, in the said process (b), a high quality single crystal with a long and low defect density can be manufactured by growing a single crystal at a speed | rate of 0.08 mm / h or more and less than 0.25 mm / h. .

<B. Second Embodiment>
As a method for producing a long ingot, it is conceivable that the crucible 1 is filled with a large amount of the raw material 2 to increase the growth time. However, it is necessary to enlarge the crucible 1 in order to fill the raw material 2 in a large amount, resulting in an increase in the size of the single crystal manufacturing apparatus, resulting in an increase in cost. Further, as the ingot becomes longer, the temperature distribution in the crucible 1 changes between the initial stage and the late stage of growth, and it becomes difficult to maintain a good temperature distribution for crystal growth. For this reason, in the second embodiment, after the crystal is grown once, the single crystal manufacturing apparatus is taken out of the furnace and refilled with the raw material 2, and the crucible is extended so as to obtain a good temperature distribution, and the crystal is grown again. To implement.

<B-1. Configuration>
FIG. 4 is a cross-sectional view of single crystal manufacturing apparatus 101 according to the second embodiment. The configuration of single crystal manufacturing apparatus 101 is the same as that of single crystal manufacturing apparatus 100 according to Embodiment 1. However, the upper lid 8 is removably joined to the crucible lid 3 and the crucible 1 can be extended with the extension crucible 11 (FIG. 5) to extend the side surface of the crucible 1.

  FIG. 5 shows a configuration of the single crystal manufacturing apparatus 101 in a state where the crucible 1 and the extension crucible 11 are combined. After the extension crucible 11 is joined to the crucible 1, the crucible lid 3 is joined not to the crucible 1 but to the extension crucible 11. Thereby, the growth region of the single crystal can be lengthened, and a long single crystal can be grown. Further, by joining another extension member on the extension crucible 11 joined on the crucible 1, the growth region of the single crystal can be further lengthened. In this way, by combining any number of extending members with the crucible 1, that is, by adding them, it is possible to appropriately extend the growth region of the single crystal to an arbitrary length.

<B-2. Manufacturing process>
Next, a single crystal manufacturing method using the single crystal manufacturing apparatus 101 according to Embodiment 2 will be described.

  First, using the single crystal manufacturing apparatus 101 shown in FIG. 4, the first single crystal growth is performed for 144 hours under the same growth conditions as in the first embodiment. Here, the diameter of the seed crystal 4 s is 80 mm, which is equal to the diameter of the pedestal 5, and the (11-20) plane of 4H—SiC is used. Further, as shown in FIG. 2, 16 through holes 7 are arranged around the base 5 at equal intervals, and the diameter of the through holes 7 is 3 mm. Further, similarly to the first embodiment, a Ta thin plate having a thickness of 50 μm is attached to the inner wall of the guide 6. As a result of the first single crystal growth, a single crystal 4 (ingot) having a center portion height of 36.2 mm was obtained.

  Next, the upper lid 8 and the upper lid heat insulating material 9 are exchanged. The reason is that when crystal growth is performed for a long time in order to produce a long ingot, the flow of the source gas into the chamber is reduced by the polycrystals precipitated in the chamber. By replacing the upper lid 8 with a new one every time a single crystal is regrown, a polycrystalline is deposited on the inner wall of the guide 6 even when producing a long crystal without reducing the flow of the source gas into the chamber. To suppress that. Note that the shape of the upper lid 8 after replacement may be different from the shape of the upper lid 8 before replacement, or may have a shape with a higher gas venting effect than the upper lid 8 before replacement.

  Further, as shown in FIG. 5, by combining the extension crucible 11 with the crucible 1, the growth region of the single crystal is extended by 20 mm. An extension guide 12 is attached to the extension crucible 11 as an extension member of the guide 6. Then, a 50 μm thick Ta thin plate is attached to the inner wall of the extension guide 12, and the extension guide heat insulating material 13 is disposed on the surface (outer wall surface) opposite to the surface of the extension guide 12 with respect to the crystal growth region. The extension crucible 11 is made of the same material as the crucible 1, and the extension guide 12 is made of the same material as the guide 6. Further, in order to avoid carbon inclusion as in the case of the guide heat insulating material 10, a structure in which the source gas does not reach the extended guide heat insulating material 13 is adopted.

  Thereafter, the second single crystal growth is performed for 199 hours under the same growth conditions (growth temperature, growth pressure) as the first time. As a result, the central portion of the single crystal 4 (ingot) grew 34.1 mm, and the total height became 70.3 mm.

  Next, the upper lid 8 and the upper lid heat insulating material 9 are exchanged.

  Moreover, as shown in FIG. 6, the extension crucible 14 is attached between the extension crucible 11 and the crucible 1, and the growth area | region of a single crystal is extended 20 mm. An extension guide 15 is attached to the extension crucible 14 as an extension member of the extension guide 12. Then, a 50 μm thick Ta thin plate is attached to the inner wall of the extension guide 15, and the extension guide heat insulating material 16 is disposed on the outer wall surface of the extension guide 15. The extension crucible 14 is made of the same material as the extension crucible 11, and the extension guide 15 is made of the same material as the extension guide 12. Further, in order to avoid carbon inclusion as in the case of the guide heat insulating material 10, a structure in which the source gas does not reach the extended guide heat insulating material 16 is adopted.

  Thereafter, the crucible 1 is filled with 2000 g of the raw material 2 and the third single crystal growth is performed for 120 hours under the same growth conditions (growth temperature and growth pressure) as the second time. As a result, the central portion of the single crystal 4 (ingot) grew 18.8 mm, and the total height became 89.1 mm.

  As described above, in this embodiment, a total of three times of growth was performed in order to obtain a long crystal. In any growth, polycrystal did not precipitate on the inner wall of the guide 6, and only the single crystal portion grew independently. The obtained single crystal 4 (ingot) was sliced with a thickness of about 1.5 mm using a wire saw in parallel with the growth direction to obtain a (0001) c-plane wafer. When the presence or absence of carbon inclusion was evaluated by polishing both surfaces of the wafer to a mirror surface and irradiating with transmitted light, no carbon inclusion was observed inside the crystal. Further, when mapping measurement of the rocking curve was performed by the X-ray diffraction method, the average of the half-width of the rocking curve of (0004) plane diffraction was 15.2 seconds, which was very high quality. Furthermore, when the number of micropipes was counted after performing the molten KOH etching process on the same sample, it was confirmed that the quality was very high.

  In this embodiment, the crystal regrowth is performed twice. However, the number of regrowths may be increased as necessary. Each time re-growth is performed, the upper lid 8 and the upper lid heat insulating material 9 are replaced, and an extension crucible, an extension guide, and an extension guide are arranged.

  As the growth time elapses, polycrystals are deposited around the pedestal 5 and the single crystal portion grows, so that the resistance of the gas flow between the guide 6 and the single crystal 4 (ingot) increases. Due to these phenomena, the more the regrowth is repeated, the more easily the polycrystal is deposited on the inner wall of the guide 6. Therefore, it is necessary to reduce the resistance of the raw material gas flow to the chamber, and the area of the through hole 7 may be enlarged at the time of regrowth. If the area of the through hole 7 is expanded within a range of 1.5 to 10% of the area of the base 5, it is possible to more effectively suppress the precipitation of polycrystals on the inner wall of the guide 6.

  In the present specification, the method of manufacturing a SiC single crystal has been described. However, it is also possible to manufacture a single crystal of another semiconductor by a similar method.

<B-3. Effect>
The single crystal manufacturing method using the single crystal manufacturing apparatus 101 according to the second embodiment includes (a) the step of filling the crucible 1 of the single crystal manufacturing apparatus 101 with the raw material 2 and attaching the seed crystal 4s to the pedestal 5; (B) a step of sublimating the raw material 2 for a predetermined time to grow the single crystal 4 on the seed crystal 4s; (c) a step of replacing the upper cover 8 of the single crystal manufacturing apparatus after the step (b); ) After the step (c), the raw material 2 is sublimated for a predetermined time, and the single crystal 4 is regrown. Since the single crystal manufacturing apparatus 101 includes the replaceable upper lid 8, the crystal growth is temporarily stopped, and the upper lid 8 is replaced and then regrown, so that the flow of the source gas into the chamber is not reduced, and the long crystal Also when the is manufactured, it is possible to suppress the precipitation of polycrystals on the inner wall of the guide 6.

  Moreover, the crucible 1 of the single final manufacturing apparatus 101 which concerns on Embodiment 2 is a structure which can extend a side wall by adding the extension crucible 11. FIG. Therefore, the single crystal manufacturing method using the single crystal manufacturing apparatus 101 according to Embodiment 2 adds the extension crucible 11 (extension member) to the crucible 1 between the step (b) and the step (d). By providing the process, it is possible to consistently maintain a good temperature distribution for crystal growth even when a long ingot is manufactured.

  In addition, if a step of expanding the area of the through hole 7 in the range of 1.5% to less than 10% of the area of the pedestal 5 between the step (b) and the step (d) is provided, During the growth, the resistance of the raw material gas flow to the chamber decreases, and the precipitation of polycrystals on the inner wall of the guide 6 can be further suppressed.

  It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

1 crucible, 2 raw materials, 3 crucible lid, 4 single crystal, 4 s seed crystal, 5 pedestal, 6 guide, 7 through hole, 8 upper lid, 9 upper lid thermal insulation, 10 guide thermal insulation, 11, 14 extension crucible, 12, 15 Extension guide, 13, 16 Extension guide insulation, 100, 101 Single crystal manufacturing equipment.

Claims (14)

A crucible containing a raw material of a single crystal;
A crucible lid that covers the upper surface of the crucible and has an opening in the center;
A pedestal that is provided in the crucible with the back surface exposed from the opening of the crucible lid, and fixes a seed crystal;
A guide that is provided on the inner wall of the crucible so as to surround the crystal growth region, and guides the source gas formed by sublimation of the source material to the seed crystal;
An upper lid that is annularly provided on the crucible lid avoiding the opening of the crucible lid and forms a chamber with the crucible lid;
With
The crucible lid is provided with a through hole communicating with the chamber around the pedestal.
Single crystal manufacturing equipment. The area of the through hole is 0.7% or more and less than 6.0% of the area of the pedestal.
The single crystal manufacturing apparatus according to claim 1. Further comprising an upper lid heat insulating material provided in the chamber,
The single crystal manufacturing apparatus according to claim 1 or 2. A guide heat insulating material provided between the guide and the inner wall of the crucible;
The single-crystal manufacturing apparatus of any one of Claims 1-3. The material of the guide is graphite having a density of 1.9 g / cm ³ or more.
The single-crystal manufacturing apparatus of any one of Claims 1-4. A guide inner wall member made of a refractory metal or a compound thereof disposed on an inner wall which is a surface of the guide with respect to a crystal growth region;
The single crystal manufacturing apparatus according to any one of claims 1 to 5. The upper lid is replaceable.
The single crystal manufacturing apparatus according to any one of claims 1 to 6. The crucible can extend the side wall by adding an extension member,
The single-crystal manufacturing apparatus of any one of Claims 1-7. The single crystal is made of silicon carbide;
The single-crystal manufacturing apparatus of any one of Claims 1-8. A single crystal manufacturing method using the single crystal manufacturing apparatus according to any one of claims 1 to 9,
(A) filling the crucible of the single crystal manufacturing apparatus with the raw material and attaching the seed crystal to the pedestal;
(B) sublimating the raw material for a predetermined time and growing a single crystal on the seed crystal;
A method for producing a single crystal. The step (b) is a step of growing the single crystal at a rate of 0.08 mm / h or more and less than 0.25 mm / h.
The method for producing a single crystal according to claim 10. A single crystal manufacturing method using the single crystal manufacturing apparatus according to claim 7,
(A) filling the crucible of the single crystal manufacturing apparatus with the raw material and attaching the seed crystal to the pedestal;
(B) sublimating the raw material for a predetermined time and growing a single crystal on the seed crystal;
(C) After the step (b), replacing the upper lid of the single crystal manufacturing apparatus;
(D) after the step (c), sublimating the raw material for a predetermined time to re-grow the single crystal;
Comprising
Single crystal manufacturing method. A single crystal manufacturing method using the single crystal manufacturing apparatus according to claim 8,
(A) filling the crucible of the single crystal manufacturing apparatus with the raw material and attaching the seed crystal to the pedestal;
(B) sublimating the raw material for a predetermined time and growing a single crystal on the seed crystal;
(C) After the step (b), replacing the upper lid of the single crystal manufacturing apparatus;
(E) after the step (b), adding the extension member to the crucible 1;
(D) After the steps (c) and (e), the step of sublimating the raw material for a predetermined time and re-growing the single crystal;
Comprising
Single crystal manufacturing method. (F) After the step (b), before the step (d), further comprising a step of expanding the area of the through hole in a range of 1.5% or more and less than 10% of the area of the pedestal.
The method for producing a single crystal according to claim 12 or 13.

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