JP2011105524A - Apparatus for producing silicon carbide single crystal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for producing an SiC single crystal, which provides a single crystal having an enlarged diameter and an elongated length while keeping the quality of the crystal. <P>SOLUTION: In the apparatus for producing an SiC single crystal, a guide part 40 for introducing a sublimation gas to a seed crystal 23 and constituting a growth space of the SiC single crystal 22 is arranged between the seed crystal 23 and an SiC raw material 30 in a container body 10. The guide part 40 is configured to have a plurality of guide members 41-44 equipped with cylindrical parts 41a-44a each having a hollow part. The plurality of guide members 41-44 are provided inside the container body 10 while the guide members are separated from each other in the axis direction of the container body 10. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a silicon carbide (hereinafter referred to as SiC) single crystal manufacturing apparatus that can be used as a material for a power MOSFET or the like.

Conventionally, for example, in Patent Document 1, an upper surface opening of a container body is closed with a lid, and an SiC raw material is disposed in the container body. An apparatus for producing a SiC single crystal for fixing a seed crystal is disclosed. In such a manufacturing apparatus, by fixing the seed crystal to the pedestal formed in the center of the lower surface of the lid, the timing at which the single crystal growing from the seed crystal and the polycrystal adhering to the periphery of the pedestal contact is delayed, It is devised to grow while expanding the diameter of the single crystal.

  However, although the manufacturing apparatus described in Patent Document 1 can delay the timing at which the single crystal and the polycrystal come into contact with each other, since the single crystal and the polycrystal finally come into contact with the growth, There was a problem that the above-mentioned single crystal diameter expansion and long growth were hindered. It is well known that when a polycrystal comes into contact with a single crystal, strain is introduced from the interface toward the single crystal, or a defect called a macro defect is generated.

  Therefore, for example, Patent Document 2 discloses the production of a SiC single crystal having a cylindrical member having a hollow portion on the side wall of a container body and having a tapered guide portion whose diameter increases toward the SiC raw material side. An apparatus is disclosed. In such a manufacturing apparatus, the guide portion allows the flow of the sublimation gas from the SiC raw material to be directed to the seed crystal, so that the growth of the single crystal is dominant, and the deposition of the polycrystal around the pedestal can be delayed. . That is, it is possible to grow a single crystal by continuously separating the single crystal and the polycrystal.

JP 10-36195 A JP 2002-60297 A

  However, the SiC single crystal manufacturing apparatus described in Patent Document 2 has the following problems. That is, at the end portion on the seed crystal side of the guide portion, when the growth of the single crystal proceeds, the single crystal is positioned between the SiC raw material in the axial direction of the container body, and the radiant heat from the SiC raw material is generated. The temperature is lowered by being hindered by the grown single crystal. In addition, since the temperature of the seed crystal decreases as the single crystal grows, the temperature of the end portion on the seed crystal side of the guide portion decreases as the temperature of the seed crystal decreases. That is, as the growth of the single crystal proceeds, the temperature of the end portion on the seed crystal side in the guide portion decreases, and the temperature gradient of the guide portion changes accordingly. Specifically, the temperature of the intermediate portion between the end portion on the seed crystal side and the end portion on the SiC raw material side in the guide portion is lowered. On the contrary, as the single crystal grows, the growth surface becomes closer to the SiC raw material, so that the temperature of the growth surface becomes higher.

  As the growth of the single crystal proceeds, when the temperature of the portion near the growth surface of the single crystal in the guide portion decreases to near the temperature of the growth surface, polycrystals adhere to the inner wall surface of the guide portion (growth). ). Then, the polycrystal adhering to the inner wall surface of the guide portion comes into contact with the single crystal, so that the diameter expansion of the single crystal is inhibited and defects and strains are introduced into the single crystal.

  In view of the above points, an object of the present invention is to provide a SiC single crystal manufacturing apparatus capable of obtaining a single crystal having a larger diameter and a longer length while maintaining the quality of the crystal.

  In order to achieve the above object, in the invention described in claim 1 of the present application, sublimation gas is transferred to the seed crystal (23) between the seed crystal (23) and the SiC raw material (30) in the container body (10). The guide part (40) which comprises the growth space of a SiC single crystal (22) is arrange | positioned while guide | inducing, The guide part (40) is a some guide provided with the cylinder part (41a-44a) which has a hollow part. It is set as the structure which has a member (41-44), and the some guide member (41-44) is provided in the inside of the container main body (10) in the state spaced apart in the axial direction of the container main body (10), respectively. It is characterized by.

  In such a SiC single crystal manufacturing apparatus, the guide portion (40) has a plurality of guide members (41 to 44), and the guide members (41 to 44) are arranged apart from each other. Yes. For this reason, each guide member (41-44) can be made into the state isolate | separated thermally.

  Therefore, in the two guide members (41 to 44) adjacent in the axial direction, even if the temperature of the guide member on the seed crystal (23) side is reduced, the guide member on the SiC raw material (30) side is 23) It can be made less susceptible to the temperature change of the guide member on the side. That is, since the temperature of the guide member on the SiC raw material (30) side can be maintained, it is possible to suppress the polycrystals from adhering to the guide member. And since it can suppress that a polycrystal adheres to a guide part (40), it is trying to make the diameter expansion and long growth of a SiC single crystal (22) further, maintaining the quality of a crystal. it can.

  For example, as in the invention described in claim 2, the plurality of guide members (41 to 44) can be fixed to the container body (10) at each end on the SiC raw material (30) side.

  Moreover, like the invention of Claim 3, in each of a plurality of guide members (41-44), the thickness of the wall surface of a cylinder part (41a-44a) can be 1 mm or more and 10 mm or less.

  Further, the guide member (41) positioned closest to the seed crystal (23) in the plurality of guide members (41 to 44) is connected to the other end portion on the seed crystal (23) side. Is not in contact with any of the seed crystal (23), the lid (20), and the container body (10), and the axis of the container body (10) is between the other end and the growth surface of the seed crystal (23). It can arrange | position so that the distance of a direction may be 1 mm or more and 10 mm or less. Moreover, like invention of Claim 5, between the opposing end surfaces of the two guide members (41-44) adjacent to the axial direction of a container main body (10) among several guide members (41-44). The distance in the axial direction of the container body (10) can be 1 mm or more and 10 mm or less.

Further, as in the invention described in claim 6, the seed crystal (23) is formed into a disk shape, and the guide member (41) positioned closest to the seed crystal (23) in the plurality of guide members (41 to 44) is provided. The inner diameter of the other end on the seed crystal (23) side is D _a , and the axial distance of the container body (10) between the other end on the seed crystal (23) side and the seed crystal (23) is h _0. Assuming that the diameter of the seed crystal (23) is A, it is possible to satisfy A + 2 (h ₀ · tan 60 ° −10) ≦ Da ≦ A + 2h ₀ · tan 60 °.

In such a manufacturing apparatus, since the inner diameter of the other end of the guide member (41) is set to A + 2h ₀ · tan 60 ° or less, SiC is formed between the seed crystal (23) and the other end surface of the guide member (41). Even if a defect occurs on the outer peripheral side surface of the single crystal (22), it is possible to prevent the defect from propagating in the growth direction due to the necking effect.

Further, as in the seventh aspect of the invention, in the end faces facing the two guide members (41 to 44) adjacent to each other in the axial direction of the container body (10) in the plurality of guide members (41 to 44), Of the guide member on the crystal (23) side, the inner diameter of the other end on the seed crystal (23) side is D _{a + 1} , the inclination of the inner wall surface of the guide member with respect to the axial direction of the container body (10) is θ _a , the axial length of the container body (10) and _{H a,} the SiC raw material (30) side of the guide member, _{D a + 2} the inner diameter of the other end portion of the seed crystal (23) side, the container body (10) The inclination between the inner wall surfaces of the guide member with respect to the axial direction is θ _{a + 1} , and the axial length of the container body (10) of the guide member is H _{a + 1,} and the container between two opposing end surfaces of the two guide members When the axial length of the body (10) and _{h 1,} The iC material (30) of the guide member positioned side other end portion inner diameter _{D a + 2 of, D a + 1 ≦ D a} + 2 ≦ (D a + 1 + 2H a · tanθ a) +2 (h 1 + H a + 1) tan60 ° -2H a + 1 · tanθ _{a + 1} can be satisfied.

  Further, as in the invention described in claim 8, each of the plurality of guide members (41 to 44) is configured to have graphite, and each of the inner wall surfaces of the cylindrical portions (41a to 44a) includes a refractory metal material. It is also possible to cover the inner guides (50a to 50d) configured and to arrange the inner guides (50) arranged on the inner wall surface across the inner wall surfaces. Moreover, like the invention of Claim 9, each inner guide (50a-50d) arrange | positioned at the said inner wall surface can be arrange | positioned mutually spaced apart.

  In such a manufacturing apparatus, it can suppress that carbon powder etc. sublimate from the inner wall of a guide part (40) or a guide member (41-44), and mix in the inside of a SiC single crystal (22), SiC. It can suppress that the quality of a single crystal (22) deteriorates.

  In this case, as in the invention described in claim 10, the thickness of the inner guide (50, 50a to 50d) can be set to 0.1 mm or more and 1 mm or less.

  Further, as in the invention described in claim 11, each of the plurality of guide members (41 to 44) is set so that the inclination of the inner wall surface with respect to the axial direction of the container body (10) is 0 ° or more and 60 ° or less. be able to.

  Furthermore, as in the invention described in claim 12, the inner diameter of at least one of the plurality of guide members (41 to 44) is increased from the seed crystal (23) side toward the SiC raw material (30) side. Can be constant.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

It is the figure which showed the cross-sectional structure of the SiC single crystal manufacturing apparatus concerning 1st Embodiment of this invention. (A) is the schematic diagram which showed the seed crystal before the growth of a SiC single crystal, and the SiC single crystal and seed crystal under growth, (b) is the seed crystal and the guide member before the growth of the SiC single crystal, It is the schematic diagram which showed the SiC single crystal, seed crystal, and guide member which are growing. It is an enlarged view of the dashed-two dotted line part shown in FIG. It is the figure which showed the cross-sectional structure of the SiC single crystal manufacturing apparatus concerning 2nd Embodiment of this invention. It is the figure which showed the cross-sectional structure of the SiC single crystal manufacturing apparatus concerning 3rd Embodiment of this invention. It is a schematic diagram of the dashed-two dotted line part shown in FIG. It is the figure which showed the cross-sectional structure of the SiC single crystal manufacturing apparatus concerning 4th Embodiment of this invention. It is the figure which showed the cross-sectional structure of the SiC single crystal manufacturing apparatus concerning 5th Embodiment of this invention. It is the figure which showed the cross-sectional structure of the SiC single crystal manufacturing apparatus concerning 6th Embodiment of this invention.

(First embodiment)
A first embodiment of the present invention will be described. FIG. 1 is a diagram showing a cross-sectional configuration of the SiC single crystal manufacturing apparatus according to the first embodiment of the present invention, and a description will be given based on this figure.

  As shown in FIG. 1, the SiC single crystal manufacturing apparatus includes a bottomed cylindrical container body 10 and a circular lid body 20 that closes the opening of the container body 10. The crucible 1 is provided. The bottom of the container body 10 is filled with a powder raw material 30 made of SiC. In the present embodiment, the powder raw material 30 corresponds to the silicon carbide raw material of the present invention.

  The lid body 20 includes a columnar seed crystal support portion 21 that protrudes downward from other peripheral portions at the center of the lower surface. The seed crystal support portion 21 is provided by being formed integrally with the lid 20, for example. A disc-shaped seed crystal 23 made of a SiC single crystal substrate for growing the SiC single crystal 22 is bonded (bonded and fixed) to the lower surface of the seed crystal support 21. ) One surface of the seed crystal 23 is bonded to the seed crystal support portion 21, and one surface opposite to the one surface is a growth surface. In this embodiment, the normal direction to the growth surface (the lower direction in the drawing in FIG. 1) is the crystal growth direction, and the SiC single crystal 22 grows downward from the growth surface of the seed crystal 23. In the present embodiment, 4H—SiC is used as the seed crystal 23.

  Further, in the container body 10, a guide portion 40 that guides the sublimation gas to the seed crystal 23 and constitutes a growth space for the SiC single crystal 22 is disposed between the seed crystal 23 and the powder raw material 30. The guide portion 40 is provided inside the container body 10 with cylindrical guide members 41 to 44 made of graphite or the like being separated from each other in the axial direction of the container body 10 (hereinafter referred to as the axial direction). Is configured.

  Hereinafter, although the guide part 40 is demonstrated, in each guide member 41-44, let the edge part by the side of the powder raw material 30 be one end part, let the edge part by the side of the seed crystal 23 be the other end part, and both ends of each guide member 41-44 Each surface will be described as an end surface, an end surface at one end as one end surface, and an end surface at the other end as the other end surface.

  Each guide member 41-44 is provided with the cylinder parts 41a-44a which have a hollow part, respectively, and is provided with the flanges 41b-44b at the one end part of the cylinder parts 41a-44a, respectively. The flanges 41b to 44b extend in a direction perpendicular to the axial direction, and the guide members 41 to 44 are held by the step portions 11 to 14 formed in the container body 10 by the flanges 41b to 44b. ing. Moreover, each guide member 41-44 is made into the taper shape whose diameter becomes large toward one end part from the other end part. In this embodiment, the guide part 40 comprised by each guide member 41-44 is also made into the taper shape. When SiC single crystal 22 is grown on seed crystal 23, the maximum aperture angle of SiC single crystal 22 with respect to the axial direction is 60 °, so the angle of the inner wall surface with respect to the axial direction of each guide member 41-44. The (taper angle) is preferably 60 ° or less.

  Further, each guide member 41 to 44 has a wall thickness in the range of 1 to 10 mm. This is due to the following reason. That is, the thinner the guide members 41 to 44, the easier the heating by radiant heat, the thinner the guide members 41 to 44. However, when the thickness is less than 1 mm, it becomes difficult to shape the graphite, and SiC There is a possibility of sublimation during the growth of the single crystal 22. On the other hand, if the thickness exceeds 10 mm, the heating effect due to radiant heat is dispersed by the thickness, so that it becomes difficult to reach a high temperature. Therefore, it is preferable that each guide member 41 to 44 has a thickness that can be easily heated, does not make it difficult to shape the graphite, and can suppress sublimation during growth. The wall thickness is 2 mm.

  Further, the guide member 41 closest to the seed crystal 23 is disposed such that the other end does not contact any of the seed crystal 23, the lid body 20, and the container body 10. Thereby, compared with the case where the other end part of the guide member 41 is in contact with any site | part, it can suppress that the heat | fever of the guide member 41 is transmitted to each site | part, and temperature falls. This can be suppressed.

  More preferably, the axial distance between the seed crystal 23 and the other end surface of the guide member 41 is 1 mm or more and 10 mm or less. That is, if the distance between the seed crystal 23 and the guide member 41 in the axial direction is less than 1 mm, the temperature difference between the seed crystal 23 and the guide member 42 is less likely to occur, and if it is greater than 10 mm, the natural growth of the SiC single crystal 22 is increased. This is because distortion and cracks are likely to occur due to stress due to the shape of the material. Similarly, the axial distance between the opposing end surfaces of the guide members 41 to 44 is preferably 1 mm or more and 10 mm or less.

  Next, the axial lengths of the guide members 41 to 44 will be described. First, the axial length of the guide member 41 closest to the seed crystal 23 will be described. FIG. 2A is a schematic diagram showing the seed crystal 23 before the growth of the SiC single crystal 22, and the SiC single crystal 22 and the seed crystal 23 that are being grown, and FIG. 2B is a diagram of the SiC single crystal 22. It is the schematic diagram which showed the seed crystal 23 and the guide member 41 before the growth, and the SiC single crystal 22, the seed crystal 23, and the guide member 41 during the growth. The hatched portion in FIG. 2B shows a region of the guide member 41 where the radiant heat is blocked by the SiC single crystal 22.

As shown in FIG. 2A, the growth surface of the seed crystal 23 is used as a reference plane, and the temperature of the seed crystal 23 when the SiC single crystal 22 begins to grow on the seed crystal 23 is Te ₀ , and the SiC single crystal 22 is Assuming that the temperature rise per unit length when grown in the axial direction is Td, the temperature of the outer peripheral side surface at the position x from the reference surface is higher by Td · (x) than the reference surface. The temperature Tf of the outer peripheral side surface at the position x from the reference surface can be expressed as follows.
(Formula 1) Tf = Te ₀ + Td · (x)
Further, as shown in FIG. 2 (b), the portion of the guide member 41 located on the most end side in the portion where the SiC single crystal 22 is located between the powder raw material 30 in the axial direction, that is, FIG. 2 (b). The temperature Tg of the part located at a distance x from the reference plane inside is expressed as follows.

First, let the growth surface of the seed crystal 23 be a reference plane, and let the distance in the axial direction between the other end surface of the guide member 41 and the growth surface of the seed crystal 23 be h ₀ . Further, in the portion of the guide member 41 from the other end portion to the distance x, the temperature increase amount per unit length in the axial direction in the guide member 41 before the growth of the SiC single crystal 22 is Ta ₀ . During the growth of the SiC single crystal 22, radiation heat is hindered by the SiC single crystal 22. Therefore, when the amount of decrease in the temperature increase due to this is Tb ₀ , the amount of temperature increase per unit length is (Ta ₀ -Tb ₀ ). Therefore, when the SiC single crystal 22 is grown as shown in FIG. 2B, the temperature of the portion of the guide member 41 located at a distance x from the seed crystal 23 is from the other end to the portion x. Since the distance is (x−h ₀ ), the temperature is higher by (Ta ₀ −Tb ₀ ) · (x−h ₀ ) than the temperature at the other end.

And the temperature of the other end part of the guide member 41 when the SiC single crystal 22 begins to grow on the seed crystal 23 is higher than Te ₀ because the other end part is closer to the powder raw material 30 side than the seed crystal 23. Th ₀ can be set. Further, the other end portion of the guide member 41 is accompanied by a decrease in the temperature of the seed crystal 23 due to a decrease in the temperature of the seed crystal 23 as the SiC single crystal 22 grows during the growth of the SiC single crystal 22. descend. Accordingly, the temperature at the other end of the guide member 41 is such that the growth amount in the SiC single crystal 22 is x-growth from the growth surface when the temperature drop due to the SiC single crystal 22 growing unit length is Tc _0. In this case, {Th ₀ −Tc ₀ · (x)} is expressed.

  As described above, the temperature Tg of the portion of the guide member 41 located at a distance x from the reference plane can be expressed as the following equation.

(Formula 2)
Tg = {Th ₀ −Tc ₀ · (x)} + (Ta ₀ −Tb ₀ ) · (x−h ₀ )
Here, when Tg decreases and approaches Tf, polycrystals adhere to the inner wall surface of the guide member 41. Therefore, if one end surface of the guide member 41 is located at a position x where Tf <Tg. It can suppress that a polycrystal adheres to the guide member 41. FIG. That is, when the SiC single crystal 22 grows in the axial direction on the seed crystal 23 and the end on the powder raw material 30 side of the outer peripheral side surface overlaps the innermost portion of the one end surface of the guide member 41 in the axial direction. By setting the length of the guide member 41 in the axial direction so that the temperature of the one end surface of the guide member 41 is higher than the temperature of the outer peripheral side surface at the position x from the reference surface, the guide member 41 is polycrystallized. Can be suppressed. Accordingly, the axial length (x−h ₀ ) of the guide member 41 is set to a length that satisfies the following expression.

(Formula 3)
Te ₀ + Td · (x) <{Th ₀ −Tc ₀ · (x)} + (Ta ₀ −Tb ₀ ) · (x−h ₀ )
Similarly, the guide members 42 to 44 have the following axial lengths. For example, in the guide member 42, one end surface of the guide member 41 is used as a reference surface, and in the above (Formula 1) to (Formula 3), instead of Te ₀ , the most powder raw material among the outer peripheral side surfaces of the SiC single crystal 22. When the end portion on the 30 side grows up to one end surface of the guide member 41, the temperature of the end portion is Te ₁ , instead of h ₀ , between the other end surface of the guide member 42 and one end surface of the guide member 41. the distance in the axial direction is h _1. Then, instead of (Ta ₀ -Tb ₀ ), the temperature rise per unit length of the guide member 42 is (Ta ₁ -Tb ₁ ), and instead of Tc ₀ , the SiC single crystal 22 grows in unit length. Therefore, the temperature decrease amount at the other end of the guide member 42 is Tc ₀ , and the temperature at the other end of the guide member 41 when the SiC single crystal 22 starts to grow on the seed crystal 23 is Th ₁ (Th ₁ > Te ₁ ). And Therefore, similarly to the guide member 41, the guide member 42 has one end face of the guide member 42 at a position satisfying x shown in the following formula, and the axial length (xh ₁ ) is expressed by the following formula. It is the length to meet.

(Formula 4)
Te ₁ + Td · (x) <{Th ₁ −Tc ₁ · (x)} + (Ta ₁ −Tb ₁ ) · (x−h ₁ )
Further, in the guide members 43 and 44, (xh ₁ ) satisfying the above (Expression 4) is set as the axial length. In the guide member 43, one end surface of the guide member 42 is used as a reference surface, and in the guide member 44, one end surface of the guide member 43 is used as a reference surface, and the amount of temperature increase per unit length of the guide members 43 and 44 is appropriately set. By replacing, the same relationship as the above (Formula 4) is established.

Further, the guide member 41 has an inner diameter at the other end as follows. FIG. 3 is an enlarged view of a two-dot chain line portion shown in FIG. As shown in FIG. 3, the guide member 41, the diameter of the seed crystal 23 A, h ₀ to the axial distance between the seed crystal 23 and the other end _face, the inner diameter of the other end when the D _a, The inner diameter satisfies A + 2 (h ₀ · tan 60 ° −10) ≦ D _a ≦ A + 2h ₀ · tan 60 °. This is due to the following reason.

That is, when the SiC single crystal 22 is grown from the seed crystal 23 while naturally expanding the diameter, the inclination in the axial direction on the outer peripheral side surface of the SiC single crystal 22 is 60 °. The diameter at a position h ₀ away from 23 is expressed as A + 2h ₀ · tan 60 °. Therefore, by setting the inner diameter of the other end of the guide member 41 to A + h ₀ · tan 60 ° or less, it is possible to obtain a necking effect, that is, to prevent the defects generated on the outer peripheral side surface of the SiC single crystal 22 from propagating in the growth direction. can do.

However, the necking effect can be obtained by setting the inner diameter of the other end portion of the guide member 41 to A + h ₀ · tan 60 ° or less. However, if the inner diameter is too small, the diameter of the SiC single crystal 22 is increased thereafter. It becomes difficult. Further, it is known that when the SiC single crystal 22 is grown while the diameter is naturally expanded, defects are easily introduced in a range of about 10 mm from the outer peripheral side surface of the SiC single crystal 22 in the axial direction. Thus, in this embodiment, it has a minimum inside diameter of _{D a} and _{A + 2 (h 0 · tan60} ° -10). As described above, the SiC single crystal manufacturing apparatus of the present embodiment is configured.

  Next, a method for manufacturing SiC single crystal 22 using such a SiC single crystal manufacturing apparatus will be described.

  First, the powder raw material 30 is disposed on the container body 10, and the seed crystal 23 is joined to the seed crystal support portion 21 of the lid 20 with an adhesive or the like. Then, the lid 20 is attached to the container body 10.

  Subsequently, the crucible 1 is placed in a heating chamber (not shown), and gas is discharged using an exhaust mechanism (not shown), whereby the inside of the heating chamber including the inside of the crucible 1 is evacuated, and heating is performed by energizing a resistance heater. Then, the crucible 1 is heated to a predetermined temperature by heating the crucible 1 with the radiant heat. At this time, by making the current value (voltage value) to each resistance heater different, heating that causes a temperature difference in the heater can be performed.

  Thereafter, a mixed gas such as inert gas (Ar gas or the like), hydrogen, or nitrogen serving as a dopant to the crystal is allowed to flow into the heating chamber. This inert gas is discharged via the exhaust pipe. Until the temperature of the growth surface of the seed crystal 23 and the temperature of the powder raw material 30 are raised to the target temperature, the sublimation from the powder raw material 30 is suppressed to the target temperature by setting the atmosphere in the heating chamber to an atmospheric pressure close to atmospheric pressure. By the way, a vacuum atmosphere is set. In this embodiment, since the SiC single crystal 22 is 4H—SiC, the temperature of the powder raw material 30 is set to 2100 to 2300 ° C., the temperature of the growth crystal surface is lowered by about 10 to 200 ° C., and the vacuum atmosphere is It is set to 1.33 Pa to 6.67 kPa (0.01 to 50 Torr).

  Thus, the powder raw material 30 is sublimated by heating the powder raw material 30, and sublimation gas is generated from the powder raw material 30. The sublimation gas rises along the inner wall of each guide portion 40 and is supplied to the seed crystal 23, and the SiC single crystal 22 expands and grows on the seed crystal 23. At this time, the sublimation gas is supplied not only to the surface of the seed crystal 23 and the growth surface of the SiC single crystal 22 but also to the lower surface of the lid 20 and the side wall of the seed crystal support portion 21. Therefore, as shown in FIG. 1, SiC polycrystal 24 grows on the surface of lid 20 and the side wall of seed crystal support portion 21.

  Note that, as described above, the guide portion 40 is configured by a plurality of guide members 41 to 44 being spaced apart in the axial direction, and each guide member 41 to 44 is in a thermally separated state. ing. Therefore, for example, even if the SiC single crystal 22 grows to one end of the guide member 41 and the radiant heat to the guide member 41 is hindered by the SiC single crystal 22, the temperature of the guide member 41 decreases. Since the guide member 42 and the guide member 42 are thermally separated from each other, the temperature of the guide member 42 can be suppressed from decreasing as the temperature of the guide member 41 decreases. That is, the temperature of the portion near the growth surface of the SiC single crystal 22 in the guide member 42 can be suppressed to the vicinity of the temperature of the growth surface, and the polycrystal can be prevented from adhering to the guide member 42. can do. The same applies to the guide members 43 and 44.

  As described above, in the SiC single crystal manufacturing apparatus according to the present embodiment, the guide portion 40 has a plurality of guide members 41 to 44, and the guide members 41 to 44 are separated in the axial direction. Are arranged. Thereby, since each guide member 41-44 will be in the state isolate | separated thermally, it can suppress that a heat | fever moves between each guide member 41-44.

  Specifically, when compared with a conventional manufacturing apparatus in which the guide portion is constituted by one cylindrical member, for example, the guide member 42 is formed by the growth of the SiC single crystal 22 and the radiant heat is hindered. Even if the temperature of 41 falls, it can be made difficult to be influenced by the temperature change of the guide member 41, and can maintain a higher temperature state than the part corresponding to the guide member 42 among the conventional guide parts. For this reason, it can suppress that a polycrystal adheres to the guide part 40 from the conventional manufacturing apparatus, and makes it expand the diameter of SiC single crystal 22, and elongate growth, maintaining the quality of a crystal | crystallization. be able to. Of course, also in the guide members 43 and 44, a higher temperature state can be maintained than the part corresponding to the guide members 43 and 44 among the conventional guide parts, and the same effect can be acquired.

  In addition, since the guide members 41 to 44 are arranged so as to be separated from each other as described above, for example, compared with the case where the guide member 40 is configured by contacting a part of the guide members 41 to 44. Furthermore, it is possible to suppress heat from moving between the guide members 41 to 44.

  Furthermore, in this embodiment, the length of each guide member 41 to 44 in the axial direction is a length that satisfies the above (Expression 3) or (Expression 4). Thereby, even if each guide member 41-44 grows to the one end part of the guide members 41-44 among the outer peripheral side surfaces of the SiC single crystal 22, the edge part by the side of the powder raw material 30 grows, the one end part of the guide members 41-44 Can be made higher than the temperature at the end of the SiC single crystal 22. Therefore, it is possible to further prevent the polycrystals from adhering to the guide members 41 to 44.

In addition, since the inner diameter of the other end of the guide member 41 is A + 2h ₀ · tan 60 ° or less, even if a defect occurs on the outer peripheral side surface of the SiC single crystal 22, the defect propagates in the growth direction due to the necking effect. Can be suppressed.

(Second Embodiment)
A second embodiment of the present invention will be described. The SiC single crystal manufacturing apparatus according to the present embodiment is different from the first embodiment in that the inner diameters of the guide members 42 to 44 are changed, and the other parts are the same as those in the first embodiment. Is omitted. FIG. 4 is a diagram showing a cross-sectional configuration of the SiC single crystal manufacturing apparatus according to the present embodiment.

  As shown in FIG. 4, in the SiC single crystal manufacturing apparatus according to the present embodiment, the guide members 41 to 44 have the same shape. That is, the inner diameter of the other end portion of the guide member 42 is smaller than the inner diameter of one end portion of the guide member 41, the inner diameter of the other end portion of the guide member 43 is smaller than the inner diameter of one end portion of the guide member 42, The inner diameter of the other end is smaller than the inner diameter of one end of the guide member 43.

  In such a SiC single crystal manufacturing apparatus, for example, the inner diameter of the other end of the guide member 42 is smaller than the inner diameter of one end of the guide member 41. For this reason, when the SiC single crystal 22 grows along the guide member 41, even if a defect occurs on the outer peripheral side surface, the defect can be prevented from propagating in the growth direction due to the necking effect of the guide member 42. . The same effect can be obtained with the guide members 43 and 44 as well. That is, the SiC single crystal manufacturing apparatus of the present embodiment can obtain the same effects as those of the first embodiment while obtaining a higher quality SiC single crystal 22.

  In addition, radiant heat is irradiated with respect to the guide members 41-44 from the powder raw material 30 not only in an axial direction but with an inclination with respect to an axial direction, or irradiated by detours. Therefore, in the two guide members 41 to 44 adjacent in the axial direction, the guide member on the seed material 23 side is not irradiated with radiant heat by the guide member on the powder raw material 30 side.

(Third embodiment)
A third embodiment of the present invention will be described. The SiC single crystal manufacturing apparatus of the present embodiment is such that the guide portion 40 is configured by guide members 41 to 43 with respect to the first embodiment, and the other parts are the same as those of the first embodiment. The description is omitted here. FIG. 5 is a diagram showing a cross-sectional configuration of the SiC single crystal manufacturing apparatus according to the present embodiment.

  As shown in FIG. 5, in the SiC single crystal manufacturing apparatus of the present embodiment, the guide portion 40 includes three guide members 41 to 43. Compared with the first embodiment, the inner diameter of the other end of the guide member 42 is made larger than the inner diameter of one end of the guide member 41, and the inner diameter of the other end of the guide member 43 is the guide member 42. It is made larger than the internal diameter of the one end part.

  In such a SiC single crystal manufacturing apparatus, the SiC single crystal 22 expands the natural diameter between the end faces of the two guide members 41 to 43 adjacent in the axial direction, so that the number of guide members 41 to 43 is effective. The same effect as that of the first embodiment can be obtained while the aperture is enlarged.

  In addition, since the guide members 42 and 43 have no function as a guide such as determining the aperture angle of the SiC single crystal 22 when the inner diameter of the other end is excessively increased, it is preferable to do the following. FIG. 6 is a schematic diagram of a two-dot chain line portion shown in FIG.

As shown in FIG. 6, in the guide member 42, the inner diameter of the other end is D _{a + 1} , the inclination of the inner wall surface of the guide member 42 with respect to the axial direction is θ _a , and the axial length of the guide member 42 is H _a . Then, the diameter of the SiC single crystal 22 at a position corresponding to one end of the guide member 42 can be expressed as D _{a + 1} + 2Ha · tan θ _a .

In the guide member 43, when the length of the guide member 43 in the axial direction is H _{a + 1} and the length of the guide members 42 and 43 in the axial direction between the two end faces facing each other is h ₁ , Since it is assumed that the diameter of the SiC single crystal 22 at the position corresponding to one end is not provided with the guide member 43, the SiC single crystal 22 grows while maintaining an angle of 60 ° with respect to the axial direction. It can be expressed as (D _{a + 1} + 2H _a · tan θ _a ) +2 (h ₁ + H _{a + 1} ) tan 60 °.

Therefore, if the inner diameter of one end portion of the guide member 43 is D _{a + 3} , the guide member 43 functions as a guide if D _{a + 3} ≦ (D _{a + 1} + 2H _a · tan θ _a ) +2 (h ₁ + H _{a + 1} ) tan 60 °. Will be fulfilled. That is, if the inner diameter of the other end of the guide member 43 is D _{a + 2} and the inclination of the inner wall surface of the guide member 43 with respect to the axial direction is θ _{a + 1} , D _{a + 2} ≦ (D _{a + 1} + 2H _a · tan θ _a ) +2 (h ₁ + H _{a + 1} ) tan 60 ° −2H _{a + 1} · tan θ _{a + 1} is sufficient. Note that the same relationship is established between the guide member 41 and the guide member 42.

(Fourth embodiment)
A fourth embodiment of the present invention will be described. The SiC single crystal manufacturing apparatus according to the present embodiment is different from the first embodiment in that the inner diameter of the guide member 42 is changed, and the other parts are the same as those in the first embodiment, and thus the description thereof is omitted here. To do. FIG. 7 is a view showing a cross-sectional configuration of the SiC single crystal manufacturing apparatus according to the present embodiment.

  As shown in FIG. 7, in the SiC single crystal manufacturing apparatus of the present embodiment, the guide member 42 has a constant inner diameter from one end to the other end, that is, the inner wall surface with respect to the axial direction. The inclination is 0 °. In such a SiC single crystal manufacturing apparatus, the SiC single crystal 22 grows along the guide member 41, that is, distortion occurs in the outer peripheral edge when growing while expanding in the radial direction. The strain can be alleviated when growing along the guide member 42 whose inner diameter is constant (not tapered). Therefore, the same effects as those of the first embodiment can be obtained while obtaining a higher quality SiC single crystal 22.

(Fifth embodiment)
A fifth embodiment of the present invention will be described. The SiC single crystal manufacturing apparatus of the present embodiment has an inner guide disposed in the guide portion 40 with respect to the first embodiment, and the other parts are the same as those of the first embodiment. Omitted. FIG. 8 is a diagram showing a cross-sectional configuration of the SiC single crystal manufacturing apparatus according to the present embodiment.

  As shown in FIG. 8, in the SiC single crystal manufacturing apparatus according to the present embodiment, each of the plurality of guide members 41 to 44 is configured such that the inner wall surfaces of the cylindrical portions 41 a to 44 a each have a refractory metal material. The inner guide 50 is covered. Specifically, the inner guide 50 is disposed across the inner wall surfaces of the guide members 41 to 44. Such an inner guide 50 is configured using a refractory metal material such as tantalum, molybdenum, tungsten or the like. Further, the thickness is set to 0.1 mm or more and 1 mm or less. This is because if the thickness of the inner guide 50 is less than 1.0 mm, the inner guide 50 may be damaged by a load applied to the inner guide 50 when the inner guide 50 is disposed or when the SiC single crystal 22 is grown. . Moreover, if it is thicker than 1.0 mm, the heating effect of radiant heat is dispersed more than the thickness of the inner guide 50.

In such a SiC single crystal manufacturing apparatus, a refractory metal material that is inert to a raw material sublimation gas (such as Si, SiC ₂ , or Si ₂ C gas) is disposed on the inner wall of the guide portion 40. It is possible to suppress carbon powder or the like from sublimating from the inner wall of the portion 40 and mixing into the SiC single crystal 22. For this reason, deterioration of the quality of the SiC single crystal 22 can be suppressed, and the same effect as that of the first embodiment can be obtained while growing the high-quality SiC single crystal 22. In particular, when tantalum is used as the inner guide 50, tantalum carbide with high thermal stability is formed by heat treatment in the graphite crucible 1, so that a high-quality SiC single crystal with fewer defects is obtained. 22 can be grown.

  In the present embodiment, the guide members 41 to 44 are connected via the inner guide 50. However, the amount of heat that moves between the guide members 41 to 44 via the inner guide 50 is the inner amount. Since the amount of heat that moves between the guide member 41 to 44 in the guide 50 and the amount of heat that moves between the guide members 41 to 44 is much smaller, the guide members 41 to 44 are thermally separated. It can be said that it is in a state.

(Sixth embodiment)
A sixth embodiment of the present invention will be described. The SiC single crystal manufacturing apparatus of the present embodiment is different from the fifth embodiment in that inner guides 50 are arranged on the inner walls of the guide members 41 to 44, and the other parts are the same as in the first embodiment. Therefore, the description is omitted here. FIG. 9 is a diagram showing a cross-sectional configuration of the SiC single crystal manufacturing apparatus according to the present embodiment.

  As shown in FIG. 9, in the SiC single crystal manufacturing apparatus according to the present embodiment, each of the guide members 41 to 44 is configured such that the inner wall surfaces of the cylindrical portions 41 a to 44 a each have a refractory metal material. It is covered with inner guides 50a to 50d. And each of the inner guides 50a-50d arrange | positioned at the said inner wall surface is arrange | positioned mutually spaced apart.

  In such a SiC single crystal manufacturing apparatus, the inner guides 50a to 50d provided in the respective guide members 41 to 44 are arranged apart from each other, and therefore, between the guide members 41 to 44 from the fifth embodiment. The effect similar to that of the fifth embodiment can be obtained while suppressing the heat transfer.

(Other embodiments)
In each said embodiment, although each guide member 41-44 demonstrated the example provided with the flange 41b-44b extended in the axial direction and the orthogonal | vertical direction at one end part, respectively, it is limited to this Instead, a configuration including flanges 41b to 44b having a predetermined inclination with respect to the axial direction may be employed.

  In the second embodiment, the example in which the guide members 41 to 44 have the same shape has been described, but the inner diameter of the other end portion of the guide member 42 is made smaller than the inner diameter of one end portion of the guide member 41, and the guide member 43. The effect of the second embodiment can be obtained by making the inner diameter of the other end of the guide member 42 smaller than the inner diameter of the one end of the guide member 42 and making the inner diameter of the other end of the guide member 44 smaller than the inner diameter of the one end of the guide member 43. Can do. At this time, considering the diameter of the SiC single crystal 22, the inner diameter of the other end of the guide member 42 is preferably equal to or larger than the inner diameter of the other end of the guide member 41, and the inner diameter of the other end of the guide member 43 is the guide. The inner diameter of the other end of the member 42 is preferably equal to or greater than the inner diameter, and the inner diameter of the other end of the guide member 44 is preferably equal to or greater than the inner diameter of the other end of the guide member 43. This is because, similarly to the inner diameter of the other end portion of the guide member 41 described in the first embodiment, if the inner diameter is too small, it is difficult to subsequently increase the diameter of the SiC single crystal 22.

  In the fourth embodiment, the example in which the inner diameter of the guide member 42 is constant has been described. For example, not only the guide member 42 but also the inner diameters of the guide members 43 and 44 can be constant. The inner diameter of only the guide member 43 can be set to a constant diameter.

  In each of the above embodiments, the manufacturing apparatus in which the powder raw material 30 is arranged in the container body 10 has been described. However, for example, the present invention is applied to a manufacturing apparatus that uses a gas supply method that supplies a raw material gas from the outside of the crucible 1. You can also.

  Furthermore, in each said embodiment, although the length of the axial direction of each guide member 41-44 is made into the length which satisfy | fills said (Formula 3) or (Formula 4), said (Formula 3) or (Formula 4) Even if the length does not satisfy (), the guide portion 40 is configured by disposing the plurality of guide members 41 to 44 apart from each other, so that polycrystals adhere to the guide portion 40 from the conventional manufacturing apparatus. Can be suppressed.

DESCRIPTION OF SYMBOLS 1 Crucible 10 Container main body 11 Step part 20 Lid body 21 Seed crystal support part 22 SiC single crystal 23 Seed crystal 30 Powder raw material 40 Guide part 41-44 Guide member

Claims (12)

A hollow cylindrical crucible (1) having a bottomed cylindrical container body (10) and a lid (20) for closing the container body (10); By disposing a seed crystal (23) made of a silicon carbide substrate in (20) and disposing a silicon carbide raw material (30) in the vessel body (10) and supplying a sublimation gas of the silicon carbide raw material (30). In the silicon carbide single crystal manufacturing apparatus in which one surface of the seed crystal (23) is used as a growth surface and the silicon carbide single crystal (22) is grown on the growth surface,
The sublimation gas is led to the seed crystal (23) between the seed crystal (23) and the silicon carbide raw material (30) in the container body (10), and the silicon carbide single crystal (22) The guide part (40) which comprises the growth space of is arrange | positioned,
The guide part (40) is configured to include a plurality of guide members (41 to 44) provided with cylindrical parts (41a to 44a) having hollow parts,
The plurality of guide members (41 to 44) are provided inside the container body (10) in a state of being separated from each other in the axial direction of the container body (10). Manufacturing equipment.   2. The carbonization according to claim 1, wherein the plurality of guide members (41 to 44) are fixed to the container main body (10) at respective end portions on the silicon carbide raw material (30) side. Silicon single crystal manufacturing equipment.   3. The silicon carbide according to claim 1, wherein each of the plurality of guide members (41 to 44) has a wall surface thickness of 1 mm or more and 10 mm or less of the cylindrical portion (41 a to 44 a). Single crystal manufacturing equipment.   The guide member (41) located closest to the seed crystal (23) in the plurality of guide members (41 to 44) has the other end on the seed crystal (23) side as the seed crystal (23), An axial direction of the container body (10) between the lid (20) and the container body (10) and between the other end and the growth surface of the seed crystal (23) 4. The apparatus for producing a silicon carbide single crystal according to claim 1, wherein the distance is 1 mm or more and 10 mm or less. 5.   The axial direction of the container body (10) between the opposing end surfaces of the two guide members (41 to 44) adjacent to each other in the axial direction of the container body (10) among the plurality of guide members (41 to 44). 5. The apparatus for producing a silicon carbide single crystal according to claim 1, wherein the distance is 1 mm or more and 10 mm or less. The seed crystal (23) is disc-shaped,
The guide member (41) located closest to the seed crystal (23) in the plurality of guide members (41 to 44) has an inner diameter at the other end on the seed crystal (23) side as D _a , and the seed crystal. When the distance in the axial direction of the container body (10) between the other end on the (23) side and the seed crystal (23) is h ₀ and the diameter of the seed crystal (23) is A, A + 2 (h _The apparatus for producing a silicon carbide single crystal according to claim 1, wherein ₀ · tan 60 ° −10) ≦ Da ≦ A + 2h ₀ · tan 60 °. In the opposing end surfaces of the two guide members (41 to 44) adjacent to each other in the axial direction of the container body (10) in the plurality of guide members (41 to 44),
In the guide member on the seed crystal (23) side, the inner diameter of the other end on the seed crystal (23) side is D _{a + 1} , and the inclination of the inner wall surface of the guide member with respect to the axial direction of the container body (10) is θ _a. , the axial length of the container body (10) of the guide member and H _a,
In the guide member on the silicon carbide raw material (30) side, the inner diameter of the other end portion on the seed crystal (23) side is D _{a + 2} , and the inclination of the inner wall surface of the guide member with respect to the axial direction of the container body (10) is θ. _{a + 1} , the axial length of the container body (10) of the guide member is Ha _{+ 1,} and the axial length of the container body (10) between the two opposing end surfaces of the two guide members with a length of _{h 1,}
The inner diameter D _{a + 2} of the other end of the guide member located on the silicon carbide raw material (30) side is D _{a + 1} ≦ D _{a + 2} ≦ (D _{a + 1} + 2H _a · tan θ _a ) +2 (h ₁ + H _{a + 1} ) tan 60 ° −2H _The apparatus for producing a silicon carbide single crystal according to claim ₁ , wherein _{a + 1} · tan θ _{a + 1} . Each of the plurality of guide members (41 to 44) is configured to have graphite, and an inner guide (50) configured such that inner wall surfaces of the cylindrical portions (41a to 44a) each include a refractory metal material. )
The silicon carbide single crystal production according to any one of claims 1 to 7, wherein the inner guide (50) disposed on the inner wall surface is disposed across the inner wall surface. apparatus. Each of the plurality of guide members (41 to 44) is configured to have graphite, and an inner guide (50a) configured such that the inner wall surfaces of the cylindrical portions (41a to 44a) each include a refractory metal material. ~ 50d),
8. The silicon carbide single crystal manufacturing apparatus according to claim 1, wherein the inner guides (50 a to 50 d) disposed on the inner wall surface are spaced apart from each other. 9. .   The said inner guide (50, 50a-50d) is 0.1 mm or more and 1 mm or less in thickness, The manufacturing apparatus of the silicon carbide single crystal of Claim 8 or 9 characterized by the above-mentioned.   Each of these guide members (41-44) has the inclination of the inner wall surface with respect to the axial direction of the said container main body (10) being 0 degree or more and 60 degrees or less, The Claim 1 thru | or 10 characterized by the above-mentioned. The manufacturing apparatus of the silicon carbide single crystal as described in any one. At least one of the plurality of guide members (41 to 44) has a constant inner diameter from the seed crystal (23) side toward the silicon carbide raw material (30) side. An apparatus for producing a silicon carbide single crystal according to any one of claims 1 to 11.

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