JP2013112553A - METHOD FOR PRODUCING SiC SINGLE CRYSTAL AND APPARATUS FOR PRODUCING SiC SINGLE CRYSTAL - Google Patents

Abstract

An object of the present invention is to provide a method for producing a SiC single crystal, which can easily prevent SiC polycrystals from precipitating on a crystal growth surface of a SiC seed crystal.
In the preparation step, a SiC single crystal manufacturing apparatus 10 including a crucible 14 containing a raw material of an SiC solution 16 and a seed shaft 30 having a lower end surface 34 to which an SiC seed crystal 36 is attached is prepared. In the attaching step, the SiC seed crystal 36 is attached to the lower end surface 34 so that the seed shaft 30 is located inside the periphery of the SiC seed crystal 36 when viewed from the axial direction of the seed shaft 30. In the production step, the crucible 14 is heated to produce the SiC solution 16. In the dipping step, the lower end of the seed shaft 30 is dipped in the SiC solution 16 and the SiC seed crystal 36 is dipped in the SiC solution 16. In the growth step, a SiC single crystal is grown on the crystal growth surface 38 of the SiC seed crystal 36.
[Selection] Figure 1

Description

  The present invention relates to an SiC single crystal manufacturing method and an SiC single crystal manufacturing apparatus, and more particularly, to an SiC single crystal manufacturing method and an SiC single crystal manufacturing apparatus by a solution growth method.

  A solution growth method is conventionally known as a method for producing a silicon carbide (SiC) single crystal. In the solution growth method, a plate-like SiC seed crystal is disposed at the lower end of the seed shaft, and the lower surface of the SiC seed crystal (hereinafter referred to as a crystal growth surface) is immersed in the SiC solution. Then, a SiC single crystal is grown on the crystal growth surface of the SiC seed crystal immersed in the SiC solution. Here, the SiC solution refers to a solution in which carbon (C) is dissolved in a melt of Si or Si alloy.

  When the SiC single crystal is grown, the SiC solution sometimes gets wet on the side surface of the lower end portion of the seed shaft. For example, the SiC solution wets the seed shaft by stirring the SiC solution or the like. The temperature of the seed shaft is lower than the temperature of the SiC solution. Therefore, the wet SiC solution is cooled by the seed shaft. Therefore, SiC polycrystal tends to be generated on the side surface of the seed shaft. If the produced SiC polycrystal adheres to the crystal growth surface of the SiC seed crystal, the growth of the SiC single crystal is inhibited. Therefore, it is preferable that the SiC polycrystal does not adhere to the crystal growth surface of the SiC seed crystal as much as possible.

  For example, Japanese Patent Application Laid-Open No. 2010-184838 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2011-98871 disclose a method for producing an SiC single crystal for the purpose of suppressing the formation of SiC polycrystal on the side surface of the lower end portion of the seed shaft. (Patent Document 2).

  In patent document 1, a seed crystal is attached to the lower end of a carbon rod. A carbon sheet is attached to the side surface of the lower end of the carbon rod. The carbon sheet has lower wettability than the carbon rod. Therefore, wetting of the carbon rod by the melt is prevented. As a result, the formation and adhesion of polycrystals to the carbon rod is prevented.

  In Patent Document 2, a seed crystal is attached to a shaft. The solution wets the side surface of the lower end of the shaft. The side surface of the lower end of the shaft is heated by the heating means. Therefore, the formation of polycrystals on the side surface of the shaft is suppressed.

JP 2010-184838 A JP2011-98871A

  However, in patent document 1, it is necessary to attach a carbon sheet to the side surface of a carbon rod lower end, and the operation | work is complicated. In patent document 2, it is necessary to provide a heating apparatus, and the apparatus for manufacturing a single crystal becomes complicated. Therefore, it is preferable that the adhesion of SiC polycrystal to the crystal growth surface of the SiC seed crystal can be suppressed by other methods.

  An object of the present invention is to provide an SiC single crystal manufacturing method and an SiC single crystal manufacturing apparatus in which an SiC polycrystal generated on a side surface of a seed shaft is unlikely to adhere to a crystal growth surface of an SiC seed crystal.

  The manufacturing method of the SiC single crystal by embodiment of this invention is equipped with a preparatory process, an attachment process, a production | generation process, an immersion process, and a growth process. In the preparation step, a SiC single crystal manufacturing apparatus is prepared that includes a crucible for storing a raw material of the SiC solution and a seed shaft having a lower end surface to which the SiC seed crystal is attached. In the attaching step, the SiC seed crystal is attached to the lower end surface so that the seed shaft is located inside the periphery of the SiC seed crystal when viewed from the axial direction of the seed shaft. In the production step, the crucible is heated to produce an SiC solution. In the dipping process, the lower end of the seed shaft is dipped in the SiC solution, and the SiC seed crystal is dipped in the SiC solution. In the growth step, a SiC single crystal is grown on the crystal growth surface of the SiC seed crystal.

  The SiC single crystal manufacturing apparatus according to the embodiment of the present invention is used for manufacturing a SiC single crystal by a solution growth method. The SiC single crystal manufacturing apparatus includes an SiC seed crystal and a seed shaft. The seed shaft has a lower end surface to which the SiC seed crystal is attached. The seed shaft is located inside the periphery of the SiC seed crystal when viewed from the axial direction of the seed shaft.

  The SiC single crystal manufacturing method and the SiC single crystal manufacturing apparatus according to the embodiment of the present invention can suppress the SiC polycrystal generated on the side surface of the seed shaft from adhering to the crystal growth surface of the SiC seed crystal.

FIG. 1 is a schematic diagram of an apparatus for producing a SiC single crystal used in an embodiment of the present invention. FIG. 2 is a schematic diagram showing a state in which the entire upper surface of the SiC seed crystal is attached to the lower end surface of the seed shaft. FIG. 3 is a schematic view showing a SiC polycrystal generated on the side surface of the seed shaft. FIG. 4 is a graph showing the relationship between the amount of protrusion and the immersion depth when the growth time is 5 hours. FIG. 5 is a graph showing the relationship between the amount of protrusion and the immersion depth when the growth time is 10 hours.

  The manufacturing method of the SiC single crystal by embodiment of this invention is equipped with a preparatory process, an attachment process, a production | generation process, an immersion process, and a growth process. In the preparation step, a SiC single crystal manufacturing apparatus is prepared that includes a crucible for storing a raw material of the SiC solution and a seed shaft having a lower end surface to which the SiC seed crystal is attached. In the attaching step, the SiC seed crystal is attached to the lower end surface so that the seed shaft is located inside the periphery of the SiC seed crystal when viewed from the axial direction of the seed shaft. In the production step, the crucible is heated to produce an SiC solution. In the dipping process, the lower end of the seed shaft is dipped in the SiC solution, and the SiC seed crystal is dipped in the SiC solution. In the growth step, a SiC single crystal is grown on the crystal growth surface of the SiC seed crystal.

  In this case, when viewed from the axial direction of the seed shaft, the SiC seed crystal projects outward from the side surface of the seed shaft. The SiC polycrystal is generated on the side surface of the seed shaft. However, unless the SiC polycrystal grows large until it protrudes outside the periphery of the SiC seed crystal, the SiC polycrystal does not reach the crystal growth surface (lower surface) of the SiC seed crystal. In other words, the SiC seed crystal having a width larger than the width of the seed shaft inhibits the SiC polycrystal from reaching the crystal growth surface. As a result, the SiC polycrystal generated on the side surface of the seed shaft becomes difficult to adhere to the crystal growth surface of the SiC seed crystal. Furthermore, the configuration of the SiC single crystal manufacturing apparatus is unlikely to be complicated.

  The manufacturing apparatus of this embodiment can further grow a high-quality SiC single crystal with few defects. More specifically, there is a difference in thermal expansion coefficient between the seed shaft and the SiC seed crystal. Therefore, thermal stress is applied to the SiC seed crystal during the growth of the SiC single crystal. However, in this manufacturing method, the contact area between the seed shaft and the SiC seed crystal is small. Therefore, the thermal stress applied to the SiC seed crystal is small. Therefore, a high-quality SiC single crystal with few defects is manufactured.

  Preferably, in the dipping step, the crystal growth surface is separated from the liquid surface of the SiC solution by 4 mm or more. In this case, adhesion of the SiC polycrystal to the crystal growth surface is further suppressed.

  Furthermore, since the SiC seed crystal is deeply immersed in the SiC solution, the temperature in the crystal growth surface tends to be uniform. Therefore, the in-plane distribution (distribution in the crystal growth plane) of the thickness (growth thickness) of the grown SiC single crystal tends to be constant.

  The SiC single crystal manufacturing apparatus according to the embodiment of the present invention is used in the manufacturing method described above.

  Hereinafter, a more specific method for producing a SiC single crystal according to an embodiment will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated.

[manufacturing device]
FIG. 1 is a schematic configuration diagram of a SiC single crystal manufacturing apparatus 10 used in an embodiment of the present invention. With reference to FIG. 1, the manufacturing apparatus 10 includes a chamber 12. The chamber 12 accommodates the crucible 14. When the SiC single crystal is manufactured, the chamber 12 is water-cooled.

  The crucible 14 accommodates the SiC solution 16. The SiC solution 16 is a raw material for SiC single crystal. The SiC solution 16 contains silicon (Si) and carbon (C).

  The raw material of the SiC solution 16 is, for example, Si alone or a mixture of Si and another metal element. The raw material is heated to form a melt, and carbon (C) is dissolved in the melt to produce a SiC solution 16. Other metal elements are, for example, titanium (Ti), manganese (Mn), chromium (Cr), cobalt (Co), vanadium (V), iron (Fe), and the like. Of these metal elements, preferred metal elements are Ti, Cr and Fe. Further preferred metal elements are Ti and Cr.

  Preferably, the crucible 14 contains carbon. The crucible 14 may be made of graphite or SiC, for example. The crucible 14 may cover the inner surface with SiC. Thereby, the crucible 14 becomes a carbon supply source to the SiC solution 16.

  The chamber 12 further accommodates a heat insulating member 18. The heat insulating member 18 is disposed so as to surround the crucible 14. In other words, the heat insulating member 18 accommodates the crucible 14.

  The chamber 12 further houses a heating device 20. The heating device 20 is, for example, a high frequency coil. The heating device 20 is disposed so as to surround the side wall of the heat insulating member 18.

  The heating device 20 induction-heats the crucible 14 to melt the raw material stored in the crucible 14. Thereby, the SiC solution 16 is produced | generated.

  The heating device 20 further maintains the SiC solution 16 at the crystal growth temperature. The crystal growth temperature depends on the composition of the SiC solution 16. A typical crystal growth temperature is 1600 to 2000 ° C.

  The manufacturing apparatus 10 further includes a rotating device 22. The rotating device 22 includes a rotating shaft 24 and a drive source 26.

  The rotating shaft 24 extends in the height direction of the chamber 12 (up and down direction in FIG. 1). The upper end of the rotating shaft 24 is located in the heat insulating member 18. A crucible 14 is disposed at the upper end of the rotating shaft 24. The lower end of the rotation shaft 24 is located outside the chamber 12. The rotating shaft 24 is connected to a drive source 26.

  The drive source 26 is disposed below the chamber 12. When manufacturing a SiC single crystal, the drive source 26 rotates the rotating shaft 24 around its central axis. Thereby, the crucible 14 rotates.

  The manufacturing apparatus 10 further includes a lifting device 28. The lifting device 28 includes a seed shaft 30 and a drive source 32.

  The seed shaft 30 extends in the height direction of the chamber 12. The upper end of the seed shaft 30 is located outside the chamber 12.

  In this example, the seed shaft 30 has a circular cross section. However, the cross section of the seed shaft 30 is not limited to a circular shape. The cross section of the seed shaft 30 may be a polygon such as a rectangle, for example.

  The seed shaft 30 may have a solid structure or a hollow structure. The seed shaft 30 may have a cooling structure.

  The seed shaft 30 is connected to a drive source 32. The drive source 32 is disposed above the chamber 12. The drive source 32 moves the seed shaft 30 up and down. The drive source 32 further rotates the seed shaft 30 about its central axis.

  The lower end of the seed shaft 30 is located in the crucible 14. A SiC seed crystal 36 is attached to the lower end surface 34 of the seed shaft 30.

  The SiC seed crystal 36 is plate-shaped and has an attachment surface 37 and a crystal growth surface 38. The attachment surface 37 corresponds to the upper surface of the SiC seed crystal 36, and the crystal growth surface 38 corresponds to the lower surface of the SiC seed crystal 36. The attachment surface 37 faces the lower end surface 34 of the seed shaft 30 and is attached to the lower end surface 34. In this example, the SiC seed crystal 36 has a disk shape. However, the shape of the SiC seed crystal 36 is not limited to a disk shape. The shape of the SiC seed crystal 36 may be a polygon such as a hexagon or a rectangle.

  The SiC seed crystal 36 is made of a SiC single crystal. Preferably, the crystal structure of SiC seed crystal 36 is the same as the crystal structure of the SiC single crystal to be manufactured. For example, when manufacturing a 4H polymorphic SiC single crystal, the 4H polymorphic SiC seed crystal 36 is used. When the 4H polymorphic SiC seed crystal 36 is used, the surface of the SiC seed crystal 36 is preferably a (0001) plane or a plane inclined at an angle of 8 ° or less from the (0001) plane. . In this case, the SiC single crystal grows stably.

  When the SiC seed crystal 36 is attached to the lower end surface 34, the seed shaft 30 is disposed inside the periphery of the SiC seed crystal 36 when viewed from the axial direction of the seed shaft 30. In short, the SiC seed crystal 36 is disposed in a flange shape at the lower end of the seed shaft 30.

  When the manufacturing apparatus 10 is viewed from the side, the width (in this example, the diameter) of the SiC seed crystal 36 is larger than the width (in this example, the diameter) of the seed shaft 30. Therefore, the seed shaft 30 can be disposed on the inner side of the periphery of the SiC seed crystal 36 when viewed from the axial direction of the seed shaft 30.

  As described above, in the manufacturing apparatus 10, the seed shaft 30 is disposed on the inner side of the periphery of the SiC seed crystal 36. Therefore, even if the SiC polycrystal is generated on the side surface of the lower end portion of the seed shaft 30, the attachment surface 37 (upper surface) of the SiC seed crystal 36 inhibits the downward movement of the SiC polycrystal. Therefore, the SiC polycrystal hardly reaches the crystal growth surface 38 (lower surface) of the SiC seed crystal 36. Therefore, even if the SiC polycrystal is generated, the SiC polycrystal hardly adheres to the crystal growth surface 38 of the SiC seed crystal 36. Hereinafter, the manufacturing method of a SiC single crystal is explained in full detail.

[Method for producing SiC single crystal]
A method for producing a SiC single crystal using the production apparatus 10 will be described. First, the manufacturing apparatus 10 is prepared (preparation process). Next, the SiC seed crystal 36 is attached to the seed shaft 30 (attachment process). Next, the crucible 14 is arrange | positioned in the chamber 12, and the SiC solution 16 is produced | generated (production | generation process). Next, the SiC seed crystal 36 is immersed in the SiC solution 16 in the crucible 14 (immersion process). Next, a SiC single crystal is grown (growing process). Hereinafter, details of each process will be described.

[Preparation process]
First, the manufacturing apparatus 10 is prepared.

[Installation process]
Subsequently, the SiC seed crystal 36 is attached to the lower end surface 34 of the seed shaft 30.

  The SiC seed crystal 36 is attached to the lower end surface 34 of the seed shaft 30 so that the seed shaft 30 is located inside the periphery of the SiC seed crystal 36 when viewed from the axial direction of the seed shaft 30. In other words, when viewed from the axial direction of the seed shaft 30, the SiC seed crystal 36 projects outward from the side surface of the seed shaft 30. In short, the entire lower end surface 34 overlaps the SiC seed crystal 36.

  In this example, the seed shaft 30 and the SiC seed crystal 36 are positioned coaxially. In other words, when viewed from the axial direction of the seed shaft 30, the center of the seed shaft 30 coincides with the center of the SiC seed crystal 36. Although it is desirable that the seed shaft 30 and the SiC seed crystal 36 are positioned coaxially, it is not always necessary.

[Generation process]
Next, the crucible 14 is disposed on the rotating shaft 24 in the chamber 12. The crucible 14 accommodates the raw material of the SiC solution 16.

  Next, the SiC solution 16 is generated. First, the chamber 12 is filled with an inert gas. And the raw material of the SiC solution 16 in the crucible 14 is heated with the heating apparatus 20 more than melting | fusing point. When the crucible 14 is made of graphite, when the crucible 14 is heated, carbon is dissolved from the crucible 14 into the melt, and an SiC solution 16 is generated. When the carbon in the crucible 14 dissolves in the SiC solution 16, the carbon concentration in the SiC solution 16 approaches the saturation concentration.

[Immersion process]
Next, the SiC seed crystal 36 is immersed in the SiC solution 16. Specifically, the seed shaft 30 is lowered by the drive source 32, and the SiC seed crystal 36 is immersed in the SiC solution 16. More specifically, the seed shaft 30 is lowered until the lower end portion of the seed shaft 30 is immersed in the SiC solution 16. Thereby, the entire SiC seed crystal 36 is immersed in the SiC solution 16, and the attachment surface 37 (upper surface) of the SiC seed crystal 36 is disposed at a position deeper than the liquid surface of the SiC solution 16. Therefore, the crystal growth surface 38 (lower surface) of the SiC seed crystal 36 is also arranged at a position deeper than the liquid surface of the SiC solution 16.

[Growth process]
After immersing SiC seed crystal 36 in SiC solution 16, SiC solution 16 is maintained at the crystal growth temperature by heating device 20. Further, the vicinity of the SiC seed crystal 36 in the SiC solution 16 is supercooled to bring SiC into a supersaturated state.

  The method for supercooling the vicinity of the SiC seed crystal 36 in the SiC solution 16 is not particularly limited. For example, the heating device 20 is controlled so that the temperature in the region near the SiC seed crystal 36 in the SiC solution 16 is lower than the temperature in other regions. Further, the vicinity of the SiC seed crystal 36 in the SiC solution 16 may be cooled by a refrigerant. Specifically, the refrigerant is circulated inside the seed shaft 30. The refrigerant is, for example, an inert gas such as helium (He) or argon (Ar). If the coolant is circulated in the seed shaft 30, the SiC seed crystal 36 is cooled. When the SiC seed crystal 36 is cooled, the vicinity of the SiC seed crystal 36 in the SiC solution 16 is also cooled.

  By supercooling the vicinity of the SiC seed crystal 36 in the SiC solution 16, a temperature gradient is formed in the SiC solution 16 in the depth direction of the crucible 14. The temperature gradient is preferably 2 to 100 ° C./cm, more preferably 5 to 50 ° C./cm.

  The SiC seed crystal 36 and the SiC solution 16 (the crucible 14) are rotated while the SiC in the region near the SiC seed crystal 36 in the SiC solution 16 is in a supersaturated state. By rotating the seed shaft 30, the SiC seed crystal 36 rotates. By rotating the rotating shaft 24, the crucible 14 rotates. The rotation direction of the SiC seed crystal 36 may be opposite to the rotation direction of the crucible 14 or the same direction. Further, the rotation speed may be constant or may vary. The seed shaft 30 gradually rises while rotating. At this time, a SiC single crystal is generated and grown on the crystal growth surface 38 of the SiC seed crystal 36 immersed in the SiC solution 16. Note that the seed shaft 30 may rotate without rising. Furthermore, the seed shaft 30 may not be raised or rotated.

  In the method for producing an SiC single crystal according to the present embodiment, since the lower end portion of seed shaft 30 is immersed in SiC solution 16, SiC solution 16 wets the side surface of seed shaft 30. The SiC solution 16 wetted on the side surface of the seed shaft 30 is cooled by the seed shaft 30. As a result, SiC polycrystal is generated on the side surface of the seed shaft 30.

  Here, when the SiC seed crystal 36 is viewed from the axial direction of the seed shaft 30, the SiC seed crystal 36 extends outward from the side surface of the seed shaft 30. Therefore, as shown in FIG. 2, SiC polycrystal is less likely to adhere to the crystal growth surface 38 than when the entire upper surface of the SiC seed crystal 36 is attached to the lower end surface of the seed shaft 30.

  More specifically, in the case of FIG. 2, the SiC polycrystal 40 generated on the side surface of the seed shaft 30 grows along the side surface of the seed shaft 30. Since the SiC seed crystal 36 does not spread outward from the side surface of the seed shaft 30, the SiC polycrystal 40 grows downward along the side surface of the seed shaft 30 and is easily formed on the crystal growth surface 38 of the SiC seed crystal 36. to arrive.

  On the other hand, as shown in FIG. 3, in the present embodiment, the SiC seed crystal 36 extends outward from the side surface of the seed shaft 30. Therefore, the SiC polycrystal 40 cannot reach the crystal growth surface 38 only by growing along the side surface of the seed shaft 30. This is because the attachment surface (upper surface) 37 of the SiC seed crystal 36 inhibits the downward growth of the SiC polycrystal 40. In this case, the SiC polycrystal 40 grows in the width direction along the attachment surface 37. The SiC polycrystal 40 does not grow downward unless it grows in the width direction until it reaches further outside than the periphery of the SiC seed crystal 36. Therefore, SiC polycrystal 40 is less likely to reach crystal growth surface 38 than in the case shown in FIG. In other words, it is possible to earn time until the SiC polycrystal 40 adheres to the crystal growth surface 38. Therefore, the SiC polycrystal 40 becomes difficult to adhere to the crystal growth surface 38.

  The distance from the liquid surface of the SiC solution 16 to the crystal growth surface 38 is desirably set to 4 mm or more. Thereby, the moving distance accompanying the growth of SiC polycrystal 40 becomes remarkably large. In other words, it is possible to further earn time until the SiC polycrystal 40 adheres to the crystal growth surface 38.

  A SiC single crystal was manufactured using a manufacturing apparatus having the same configuration as in FIG. At this time, the amount of jump of SiC polycrystal (hereinafter simply referred to as the amount of jump, see FIG. 3) T was measured. The pop-out amount T is based on the crystal growth surface of the SiC seed crystal, and indicates the distance (distance in the perpendicular direction of the crystal growth surface) from this reference to the lower end of the SiC polycrystal. In the measurement of the protrusion amount T, the ratio R of the diameter D2 of the lower end portion of the seed shaft to the diameter D1 of the SiC seed crystal, the distance (immersion depth) L from the liquid surface of the SiC solution to the crystal growth surface of the SiC seed crystal, The growth time of the SiC single crystal was changed. The temperature gradient in the vicinity of the SiC seed crystal of the SiC solution was 12 ° C./cm.

  The measurement results are shown in Table 1. In Table 1, when the pop-out amount T takes a negative value, it indicates that the lower end of the SiC polycrystal is located above the crystal growth surface of the SiC single crystal, and when the pop-out amount T takes a positive value. It shows that the lower end of the SiC polycrystal is located below the crystal growth surface of the SiC single crystal. If the lower end of the SiC polycrystal is positioned above the crystal growth surface of the SiC single crystal, the SiC polycrystal will hardly reach the crystal growth surface of the SiC single crystal. Therefore, in this case, it means that the SiC polycrystal hardly adheres to the crystal growth surface. On the other hand, if the lower end of the SiC polycrystal is positioned below the crystal growth surface of the SiC single crystal, the SiC polycrystal easily reaches the crystal growth surface of the SiC single crystal. Therefore, in this case, it means that the SiC polycrystal tends to adhere to the crystal growth surface.

  Referring to Table 1, when the diameter D1 of the SiC seed crystal was smaller than the diameter D2 of the seed shaft (Examples 1 to 9), the pop-out amount T was negative. Therefore, it was confirmed that the SiC polycrystal did not jump out of the crystal growth surface of the SiC single crystal. On the other hand, when the diameter D1 of the SiC seed crystal and the diameter D2 of the seed shaft were the same (Comparative Examples 1 and 2), the pop-out amount T was positive. Therefore, it was confirmed that the SiC polycrystal jumps out of the crystal growth surface of the SiC single crystal. If the diameter D1 of the SiC seed crystal was larger than the diameter D2 of the seed shaft, the SiC polycrystal was difficult to adhere to the crystal growth surface of the SiC single crystal.

  4 and 5 show graphs of the measurement results in Table 1. FIG. 4 is a graph when the growth time is 5 hours, and FIG. 5 is a graph when the growth time is 10 hours. The horizontal axis of each graph of FIG.4 and FIG.5 shows the penetration depth L (mm), and a vertical axis | shaft shows the protrusion amount T (mm).

  4 and 5, when the immersion depth L is 4 mm or more, the pop-out amount T is remarkably reduced as compared with the case where the penetration depth L is less than 4 mm. That is, when the immersion depth L is 4 mm or more, the SiC polycrystal is not easily attached to the crystal growth surface of the SiC seed crystal.

  As mentioned above, although embodiment of this invention has been explained in full detail, these are illustrations to the last and this invention is not limited at all by the above-mentioned embodiment.

10: Manufacturing apparatus, 14: Crucible, 16: SiC solution, 30: Seed shaft, 34: Lower end surface, 36: SiC seed crystal, 38: Crystal growth surface, 40: SiC polycrystal

Claims (3)

Preparing a SiC single crystal manufacturing apparatus comprising a crucible containing a raw material of the SiC solution and a seed shaft having a lower end face to which the SiC seed crystal is attached;
An attachment step of attaching the SiC seed crystal to the lower end surface so that the seed shaft is located inside the periphery of the SiC seed crystal as viewed from the axial direction of the seed shaft;
Generating the SiC solution by heating the crucible;
An immersion step of immersing the lower end of the seed shaft in the SiC solution, and immersing the SiC seed crystal in the SiC solution;
A method for producing a SiC single crystal, comprising a growth step of growing a SiC single crystal on a crystal growth surface of the SiC seed crystal.   2. The method for producing a SiC single crystal according to claim 1, wherein in the dipping step, the crystal growth surface is separated from the liquid surface of the SiC solution by 4 mm or more. An apparatus for producing a SiC single crystal by a solution growth method,
A seed shaft having a lower end surface;
SiC seed crystal attached to the lower end surface,
The manufacturing apparatus in which the seed shaft is located inside the periphery of the SiC seed crystal when viewed from the axial direction of the seed shaft.

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