JP6413925B2 - Silicon carbide single crystal manufacturing equipment - Google Patents

Description

  The present invention relates to a silicon carbide (hereinafter referred to as SiC) single crystal manufacturing apparatus.

Conventionally, in a SiC single crystal manufacturing apparatus that manufactures a SiC single crystal by gas growth, the gas flow path is blocked by the adhesion of the polycrystal to the wall surface that constitutes the growth chamber of the SiC single crystal, and the continuous growth of the SiC single crystal. There is a problem of hindering. As a solution to this problem, there is a technique for suppressing the adhesion of polycrystals to the wall surface by introducing H ₂ gas or Ar gas. Therefore, the adhesion of polycrystals on the wall surface in the region where the temperature is lower cannot be suppressed. As a result, continuous growth of the SiC single crystal cannot be performed.

  For this reason, the SiC single crystal manufacturing apparatus shown by patent document 1 is proposed as an alternative to the above-mentioned technique. In this SiC single crystal manufacturing apparatus, a particle generation mechanism is configured by arranging a heat insulating material protruding from the inner wall surface of the heating container while surrounding the pedestal. This forms a steep temperature gradient so that particles are actively generated. In addition, by collecting the particles with a particle recovery mechanism, it is possible to prevent unreacted gas from polycrystallizing on the wall surface before it is converted to particles, and to prevent the exhaust gas flow path from being blocked by SiC polycrystal. doing. Further, by collecting the particles, it is possible to prevent the exhaust gas flow path from being blocked by the accumulation of particles. Thereby, the continuous growth of the SiC single crystal is enabled.

Japanese Patent No. 499965

  However, even with the SiC single crystal manufacturing apparatus disclosed in Patent Document 1, polycrystals adhere in a region at a temperature lower than the surface of the grown crystal, and the SiC single crystal cannot be continuously grown sufficiently.

  In view of the above points, an object of the present invention is to provide a SiC single crystal manufacturing apparatus capable of continuous growth for a longer time.

In order to achieve the above object, according to the first aspect of the present invention, a pedestal (9) is disposed in a cylindrical reaction vessel (8) that constitutes a reaction chamber in which a SiC single crystal (6) is grown. By placing a seed crystal (5) composed of a SiC single crystal substrate on the pedestal and supplying a SiC source gas (3a) from below the seed crystal, the SiC single crystal is formed on the surface of the seed crystal. In a SiC single crystal manufacturing apparatus to be grown, a gas supply for supplying a gas containing at least one of Si and C, which is a raw material of SiC, to the downstream side of the flow path of the raw material gas from the growth surface of the SiC single crystal in the reaction vessel Means (8c, 14, 18) , and the gas supply means includes an auxiliary gas supply source (14) for supplying an auxiliary gas (15) containing a material to be a raw material of silicon carbide, and a silicon carbide single substance in the reaction vessel. Than the crystal growth surface Charges on the downstream side of the flow path of the gas, and the first gas ejection port for ejecting the auxiliary gas and (8c), characterized in that it is configured to have a.

  According to such a configuration, the auxiliary gas can be supplied from the gas supply means to a portion that is lower in temperature than the growth surface of the SiC single crystal during the growth of the SiC single crystal. As a result, it is possible to reduce the supersaturation degree of SiC in the region where the temperature is lower than the growth surface of the SiC single crystal, and it is possible to suppress the polycrystal from adhering to this region, and to keep the SiC single crystal 6 continuous for a longer time. It becomes possible to grow.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows an example of a corresponding relationship with the specific means as described in embodiment mentioned later.

It is sectional drawing of the SiC single crystal manufacturing apparatus concerning 1st Embodiment of this invention. It is sectional drawing of the SiC single crystal manufacturing apparatus concerning 2nd Embodiment of this invention. FIG. 3 is an enlarged cross-sectional perspective view in the vicinity of a gas ejection port 8c in FIG. It is sectional drawing of the SiC single crystal manufacturing apparatus concerning 3rd Embodiment of this invention. It is sectional drawing of the SiC single crystal manufacturing apparatus concerning 4th Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other will be described with the same reference numerals.

(First embodiment)
An SiC single crystal manufacturing apparatus according to a first embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 1, the SiC single crystal manufacturing apparatus 1 supplies a source gas 3a from a source gas supply source 3 through an inlet 2 provided at the bottom and out of the source gas 3a through an outlet 4 at the top. Unreacted gas is discharged. Then, the SiC single crystal manufacturing apparatus 1 forms an ingot of the SiC single crystal 6 by growing the SiC single crystal 6 on the seed crystal 5 made of the SiC single crystal substrate disposed in the apparatus.

  The SiC single crystal manufacturing apparatus 1 includes a source gas supply source 3, a vacuum vessel 7, a reaction vessel 8, a pedestal 9, a heat insulating material 10, a rotary pulling mechanism 11, first and second heating devices 12 and 13, and auxiliary gas supply. A source 14 is provided.

  The raw material gas supply source 3 includes a SiC raw material gas 3a containing Si and C (for example, a mixed gas of a silane-based gas such as silane and a hydrocarbon-based gas such as propane) and an inlet 2 together with a carrier gas as necessary. Supply more.

  The vacuum vessel 7 is made of quartz glass or the like, has a hollow cylindrical shape, and is erected with the central axis directed in the vertical direction. The vacuum vessel 7 can introduce and discharge the source gas 3a and the like, and can accommodate other components of the SiC single crystal manufacturing apparatus 1 and can be depressurized by evacuating the pressure of the accommodated internal space. It is structured. An inlet 2 for the source gas 3a is provided at the bottom of the vacuum vessel 7, and an outlet 4 for the source gas 3a is provided at the top (specifically, above the side wall).

  The reaction vessel 8 constitutes a crucible, has a hollow shape, and constitutes a reaction chamber in which the SiC single crystal 6 is grown on the surface of the seed crystal 5. The reaction vessel 8 is made of, for example, graphite, or graphite whose surface is coated with a refractory metal carbide such as TaC (tantalum carbide) or NbC (niobium carbide) so that thermal etching can be suppressed. Yes. The reaction vessel 8 is disposed from the upstream side in the flow direction of the raw material gas 3 a to the downstream side with respect to the pedestal 9 so as to surround the pedestal 9. By this reaction vessel 8, the raw material gas 3 a is decomposed while excluding particles contained in the raw material gas 3 a until the raw material gas 3 a supplied from the inlet 2 is guided to the seed crystal 5.

  Specifically, the reaction vessel 8 is configured to have a cylindrical member having a hollow portion, and in the case of the present embodiment, is configured from a bottomed cylindrical member. The reaction vessel 8 is provided with a gas inlet 8a at the bottom, and the raw material gas 3a is introduced into the reaction vessel 8 through the gas inlet 8a.

  Further, a gas introduction path 8 b and a gas jet port 8 c are formed on the inner peripheral wall surface of the reaction vessel 8. The gas introduction path 8b is a path for supplying the auxiliary gas 15 from the auxiliary gas supply source 14 described later to the gas outlet 8c. In the present embodiment, the gas introduction path 8 b is introduced into the inside of the reaction vessel 8, specifically, the inner peripheral surface and the outer circumference of the reaction vessel 8 so as to be introduced through the gas introduction port 2 a formed at the bottom of the vacuum vessel 7. Between the two surfaces, an annular shape extends upward from the bottom surface of the vacuum vessel 7. The gas ejection port 8 c is for ejecting the auxiliary gas 15 around the seed crystal 5 or the SiC single crystal 6. The gas ejection port 8 c ejects the auxiliary gas 15 to a portion that is lower in temperature than the growth surface of the SiC single crystal 6 when the SiC single crystal 6 is grown. In the case of the present embodiment, the gas outlet 8c is formed on the side surface of the seed crystal 5, the SiC single crystal 6 and the pedestal 9, that is, the outer peripheral surface surrounding the growth surface of the SiC single crystal 6 or the downstream of the raw material gas 3a in the flow direction. It is formed at a position where the auxiliary gas 15 can be ejected to the side. The gas outlets 8c may be scattered at a plurality of positions at equal intervals, but in this embodiment, the gas outlets 8c are formed over the entire circumference of the inner peripheral surface of the reaction vessel 8 and are arranged around the circumference of the SiC single crystal 6. The auxiliary gas 15 is ejected uniformly.

  In the case of this embodiment, the reaction vessel 8 includes an outer peripheral portion 8d constituting a portion above the gas jet port 8c on the outer peripheral surface and the inner peripheral surface, and a portion below the gas jet port 8c on the inner peripheral surface. Are formed by an inner peripheral portion 8e and a bottom portion 8f in which a gas introduction port 8a is formed.

  The outer peripheral portion 8d is formed of a cylindrical member, and the inner diameter is enlarged by forming a concave portion on the inner wall surface at a lower position where the inner peripheral portion 8e is disposed. In the outer peripheral portion 8d, at the boundary position where the inner diameter is changed, the inner diameter is gradually enlarged in the direction opposite to the flow direction of the raw material gas 3a to form a tapered surface 8g.

  The inner peripheral portion 8e is formed of a cylindrical member, is disposed at a position corresponding to the concave portion of the inner wall surface of the outer peripheral portion 8d, and has an outer diameter smaller than the inner diameter of the concave portion in the outer peripheral portion 8d. Thus, a gap is formed between the inner peripheral portion 8e and the outer peripheral portion 8d, and the gas introduction path 8b is configured by this gap. Further, at the upper position in the inner peripheral portion 8e, the outer diameter is gradually enlarged toward the direction opposite to the flow direction of the raw material gas 3a, thereby forming a tapered surface 8h. The tapered surface 8h is opposed to the tapered surface 8g formed on the outer peripheral portion 8d. As a result, a gas outlet 8c is formed between the both tapered surfaces 8g and 8h, which is directed obliquely upward toward the inside of the reaction vessel 8, so that the auxiliary gas 15 is directed in the flow direction of the raw material gas 3a. Thus, the gas can be ejected from the gas ejection port 8c. Therefore, the auxiliary gas 15 can be introduced into the reaction vessel 8 without hindering the flow of the raw material gas 3a.

  The bottom 8f is a disk-shaped member having a gas introduction port 8a opened in a circular shape at the center. Here, the case where the bottom portion 8f is formed of a separate member from the inner peripheral portion 8e has been described, but these may be integrated.

  The pedestal 9 is composed of a plate-like member arranged coaxially with the central axis of the reaction vessel 8. For example, the pedestal 9 is made of graphite, for example, or made of graphite whose surface is coated with a refractory metal carbide such as TaC (tantalum carbide) or NbC (niobium carbide) so that thermal etching can be suppressed. ing. A seed crystal 5 is affixed to the pedestal 9, and an SiC single crystal 6 is grown on the surface of the seed crystal 5. The pedestal 9 has a shape corresponding to the shape of the seed crystal 5 to be grown, for example, a disk shape, and is connected to the rotary pulling mechanism 11 on the surface opposite to the surface on which the seed crystal 5 is disposed.

  The heat insulating material 10 constitutes an outer peripheral heat insulating material that insulates the outer periphery of the reaction vessel 8 and the base 9. In this embodiment, the heat insulating material 10 is formed in a cylindrical shape, for example, graphite, or graphite whose surface is coated with a refractory metal carbide such as TaC (tantalum carbide) or NbC (niobium carbide). So that thermal etching can be suppressed. The inner diameter of the heat insulating material 10 is larger than the outer diameter of the reaction vessel 8.

  The rotary pulling mechanism 11 rotates and pulls the pedestal 9 through the pipe material 11a. One end of the pipe material 11 a is connected to the surface of the pedestal 9 on the side opposite to the attaching surface of the seed crystal 5, and the other end is connected to the main body of the rotary pulling mechanism 11. The pipe material 11a is also made of, for example, graphite, or graphite whose surface is coated with a refractory metal carbide such as TaC (tantalum carbide) or NbC (niobium carbide) so that thermal etching can be suppressed. ing. With such a configuration, the pedestal 9, the seed crystal 5 and the SiC single crystal 6 can be rotated and pulled together with the pipe material 11a, and the SiC single crystal 6 has a desired temperature distribution while the growth surface of the SiC single crystal 6 has a desired temperature distribution. With the growth, the growth surface temperature can always be adjusted to a temperature suitable for growth.

  The first and second heating devices 12 and 13 are configured by, for example, a heating coil (induction heating coil or direct heating coil) and are disposed so as to surround the vacuum vessel 7. In the case of this embodiment, the 1st, 2nd heating apparatuses 12 and 13 are comprised by the coil for induction heating, for example, it is set as the structure which can cool the inside by water with the coil for induction heating. These first and second heating devices 12 and 13 are configured so that the temperature of the target place can be controlled independently, and the first heating device 12 is disposed at a position corresponding to the lower side of the reaction vessel 8, The second heating device 13 is disposed at a position corresponding to the base 9. Therefore, the temperature of the lower part of the reaction vessel 8 can be controlled by the first heating device 12, and the temperature around the pedestal 9, the seed crystal 5 and the SiC single crystal 6 can be controlled by the second heating device 13. .

  The auxiliary gas supply source 14 supplies the auxiliary gas 15. The auxiliary gas 15 is a gas that is a raw material for SiC, and is a gas containing at least one of Si and C. As the gas containing Si, for example, a silane-based gas, and as the gas containing C, for example, propane can be used. As the gas containing both Si and C, for example, a mixed gas of silane-based gas and propane or trimethylsilane A gas such as can be used.

  With this structure, the SiC single crystal manufacturing apparatus 1 according to the present embodiment is configured. Then, the manufacturing method of the SiC single crystal 6 using the SiC single crystal manufacturing apparatus 1 concerning this embodiment is demonstrated.

  First, the seed crystal 5 is attached to the pedestal 9 and installed in the reaction vessel 8. At this time, the height of the pedestal 9 and the seed crystal 5 of the rotary pull-up mechanism 11 is adjusted so that the auxiliary gas 15 is ejected from the gas outlet 8 c toward the side surfaces of the seed crystal 5 and the pedestal 9.

  And the 1st, 2nd heating apparatuses 12 and 13 are controlled and desired temperature distribution is attached. That is, the source gas 3a is recrystallized on the surface of the seed crystal 5 so that the SiC single crystal grows, and the sublimation rate is higher in the reaction vessel 8 than the recrystallization rate. To do. By doing in this way, the surface side of the seed crystal 5 which should grow the SiC single crystal 6 is heated. Moreover, since the arrangement position of the 2nd heating apparatus 13 is a position corresponding to the base 9, the back surface side of the base 9 can be prevented from being heated so much.

Further, the raw material gas is supplied into the reaction chamber from the raw material gas supply source 3 while introducing a carrier gas using an inert gas such as Ar or He or an etching gas such as H ₂ or HCl while bringing the vacuum vessel 7 to a desired pressure. Introduce 3a. Thereby, source gas 3a flows as shown by an arrow in FIG. 1, and is supplied to seed crystal 5 to grow SiC single crystal 6. Then, the base 9, the seed crystal 5, and the SiC single crystal 6 are rotated through the pipe material 11 a by the rotary pulling mechanism 11 and pulled up according to the growth rate of the SiC single crystal 6. Thereby, the height of the growth surface of SiC single crystal 6 is kept substantially constant, and the temperature distribution of the growth surface temperature can be controlled with good controllability.

  Further, the auxiliary gas 15 is introduced from the auxiliary gas supply source 14 through the gas introduction path 8b, and ejected from the gas ejection port 8c. Thereby, the region where the auxiliary gas 15 is at a lower temperature than the growth surface of the SiC single crystal 6 as shown by the arrow in FIG. 1, specifically, the side surface of the SiC single crystal 6 or the seed crystal 5 or the side surface of the pedestal 9. For example, the auxiliary gas 15 is supplied above the growth surface of the SiC single crystal 6. Therefore, the supersaturation degree of the SiC raw material in the region where the temperature is lower than the growth surface of the SiC single crystal 6 is increased, and SiC crystal particles can be nucleated. Then, the nucleated SiC crystal particles fall downward and are moved from the exhaust gas flow path, and the supersaturation degree of SiC on the wall surface of the reaction vessel 8 constituting the exhaust gas flow path is lowered. .

  As a result, it is possible to suppress polycrystals from adhering to a region having a temperature lower than the growth surface of the SiC single crystal 6 based on the unreacted gas of the raw material gas 3a, and the flow path of exhaust gas such as unreacted gas is blocked. It can be suppressed. Therefore, the SiC single crystal 6 can be continuously grown for a longer time.

  As described above, when the SiC single crystal 6 is grown from the gas ejection port 8 c, the auxiliary gas 15 is ejected to a portion that is lower in temperature than the growth surface of the SiC single crystal 6. As a result, it is possible to reduce the supersaturation degree of SiC in a region where the temperature is lower than the growth surface of SiC single crystal 6, and it is possible to prevent polycrystals from adhering to this region. Continuous growth is possible.

(Second Embodiment)
A second embodiment of the present invention will be described. The present embodiment is provided with a mechanism that suppresses the auxiliary gas 15 from touching the reaction vessel 8 with respect to the first embodiment, and is otherwise the same as the first embodiment, so the first embodiment Only different parts will be described.

  As shown in FIG. 2, in the SiC single crystal manufacturing apparatus 1 according to the present embodiment, not only the auxiliary gas 15 but also Ar or the like on the downstream side of the flow path of the source gas 3a from the portion where the auxiliary gas 15 is introduced. Inert gas 16 is introduced.

  Specifically, a gas introduction path 8i is provided inside the reaction vessel 8, and a gas injection port 8j is provided in the reaction vessel 8 on the downstream side of the flow path of the raw material gas 3a from the gas injection port 8c, that is, at an upper position. ing. The gas outlets 8j may be scattered at a plurality of positions at equal intervals. However, as shown in FIG. 3, in the present embodiment, the gas outlets 8j are formed over the entire circumference of the inner peripheral surface of the reaction vessel 8, and are formed of a single SiC. The inert gas 16 is jetted uniformly around the entire periphery of the crystal 6.

  In the case of the present embodiment, the configuration of the outer peripheral portion 8d is changed with respect to the first embodiment, and the inner diameter is expanded by forming a concave portion on the inner wall surface above the gas jet port 8c in the outer peripheral portion 8d. ing. A wall surface protruding in the direction opposite to the flow direction of the raw material gas 3a is formed at the boundary position where the inner diameter is changed in the outer peripheral portion 8d, and a tapered surface 8k is formed by this wall surface.

  Moreover, the inner peripheral part 8m comprised by the cylindrical member is provided inside the outer peripheral part 8d, and the inner peripheral part 8m is arrange | positioned in the recessed part of the outer peripheral part 9d. The outer diameter of the inner peripheral portion 8m is smaller than the inner diameter of the concave portion in the outer peripheral portion 8d. Accordingly, a gap is formed between the inner peripheral portion 8m and the outer peripheral portion 8d, and the gas introduction path 8i is configured by this gap. Further, at the lower position in the inner peripheral portion 8m, the inner diameter is gradually enlarged in the direction opposite to the flow direction of the raw material gas 3a to constitute a tapered surface 8n. The tapered surface 8n is opposed to the tapered surface 8k formed on the outer peripheral portion 8d. As a result, a gas jet port 8j directed obliquely upward is formed between both tapered surfaces 8k and 8n, and the inert gas 16 is jetted from the gas jet port 8j so as to be directed in the flow direction of the raw material gas 3a. It is supposed to be made. Therefore, the inert gas 16 can be introduced into the reaction vessel 8 without hindering the flow of the raw material gas 3a.

  Furthermore, the connection part 8p which connects these in the upper position of the outer peripheral part 8d and the inner peripheral part 8m is formed. The connecting portion 8p is composed of an annular member and closes the upper end of the gas introduction path 8i. A gas introduction hole 8q is formed in a part of the connecting portion 8p.

  A gas introduction port 2b is formed on the upper surface of the vacuum vessel 8, and is connected to the gas introduction hole 8q to guide the inert gas 16 from the inert gas supply source 17 to the gas introduction path 8i. The gas is ejected from the gas ejection port 8j.

  Thus, the inert gas 16 is introduced downstream of the auxiliary gas 15 in the flow direction of the raw material gas 3a. Due to the shielding effect of the inert gas 16, the unreacted gas of the raw material gas 3 a can be prevented from touching the inner wall surface of the reaction vessel 8. Therefore, further, the polycrystal is prevented from adhering to the exhaust gas flow path, and the SiC single crystal 6 can be continuously grown for a longer time.

(Third embodiment)
A third embodiment of the present invention will be described. The present embodiment is different from the first and second embodiments in the exhaust gas discharge route such as unreacted gas, and the other is the same as the first and second embodiments. Only differences from the second embodiment will be described. Here, the case where the configuration of the present embodiment is applied to the configuration in which the inert gas 16 is also introduced as in the second embodiment will be described, but the present embodiment can of course be applied to the first embodiment.

  As shown in FIG. 4, the SiC single crystal manufacturing apparatus 1 according to the present embodiment includes the outlet 4 at the bottom 8 f of the reaction vessel 8 and a guide wall 8 s formed of a cylindrical member. The guide wall 8s is arranged so as to surround the periphery of the inflow port 2, thereby guiding the raw material gas 3a to the pedestal 9 side, and the outflow port 4 is located outside the guide wall 8s, that is, through the guide wall 8s. 2 is formed on the opposite side.

  Further, the basic structure of the reaction vessel 8 is the same as that of the second embodiment except that the guide wall 8s is provided. However, in this embodiment, the upper side is the gas outlet 8c and the lower side. Is the gas outlet 8j. That is, the auxiliary gas 15 is jetted from the upper gas jet port 8c, and the inert gas is jetted from the lower gas jet port 8j. Accordingly, the auxiliary gas supply source 14 and the inert gas supply source 17 are connected to the second connection so that the auxiliary gas 15 is introduced from the gas introduction port 2b and the inert gas 16 is introduced from the gas introduction port 2a. It has been replaced with respect to the embodiment.

  In the case of such a configuration, after the source gas 3a is supplied to the growth surface of the SiC single crystal 6, the exhaust gas containing the unreacted gas is folded downward and discharged from the outlet 4. Yes.

  Thus, even if it is set as the form which discharges exhaust gas from the downward direction, it is made to equip the inner wall surface of the reaction container 8 with gas jet nozzles 8c and 8j. Specifically, the auxiliary gas 15 and the inert gas 16 ejected from the gas ejection ports 8c and 8j are ejected toward the guide wall 8s. Even in such a configuration, the same effects as those of the first and second embodiments can be obtained. Further, since the gas jets 8c and 8j can be separated from the growth surface of the SiC single crystal 6, the auxiliary gas 15 and the inert gas 16 jetted from the gas jets 8c and 8j give the growth of the SiC single crystal 6. It is possible to reduce the influence.

  In the case of the structure in which the source gas 3a flows from the lower side to the upper side and then flows back downward again as in the present embodiment, the carrier gas 3a does not flow upward from the base 9 so that the source gas 3a does not flow upward. It is preferable to provide the gas supply source 19 and introduce the carrier gas 20 downward.

(Fourth embodiment)
A fourth embodiment of the present invention will be described. This embodiment is different from the third embodiment in that the third embodiment is further provided with a SiC raw material source that constitutes the SiC supply means, and the others are the same as the third embodiment. Only the part will be described.

  As shown in FIG. 5, in this embodiment, the SiC raw material source 18 is provided on the downstream side of the SiC single crystal 6 in the flow path of the raw material gas 3a. Specifically, a flange portion 8t is provided on the outer peripheral surface of the guide wall 8s, and the SiC raw material source 18 is disposed on the flange portion 8t. The SiC raw material source 18 is a solid containing a material that is a raw material for SiC, and for example, a SiC solid is used. As the SiC solid, block-like or powdery SiC can be used. In the case of using powdered SiC, the surface area per unit volume is larger than that in the case of using block-like SiC, so that more SiC source gas can be sublimated. In particular, it is preferable to use a powder having a particle size of 1 mm or less because sublimation efficiency is improved. On the other hand, if the particle size is too fine, the gas flow path between the particles becomes smaller. Therefore, the particle size is preferably 0.1 mm or more.

  Thus, by providing the SiC raw material source 18 on the downstream side of the SiC single crystal 6 in the flow path of the raw material gas 3a, it becomes possible to further increase the supersaturation degree of the SiC raw material in this region, and more SiC It becomes possible to facilitate the nucleation of the crystal particles in the gas phase. By promoting nucleation in the gas phase, the unreacted gas is reacted and the consumption of raw materials is promoted. As a result, it is possible to prevent the polycrystal from adhering to the wall surface, and further, the exhaust gas flow path can be prevented from being blocked, and the SiC single crystal 6 can be continuously grown for a longer time.

(Other embodiments)
The present invention is not limited to the embodiment described above, and can be appropriately changed within the scope described in the claims.

  For example, in each of the above embodiments, an example of the structure of the SiC single crystal manufacturing apparatus 1 has been described. However, a structure other than the structure described here may be used. That is, the SiC single crystal 6 is grown in the reaction vessel 8 by supplying the raw material gas 3 from below the seed crystal 5, and the SiC raw material gas is located downstream of the raw material gas 3 a from the growth surface of the SiC single crystal 6. Any gas supply means capable of supplying the gas may be used. Examples of the gas supply means include an auxiliary gas supply source 14 for ejecting the auxiliary gas 15 from the gas ejection port 8c, an SiC raw material source 18 composed of a solid containing a material that is an SiC raw material, and the like.

  Further, although the gas ejection port 8 c is configured in the wall surface of the reaction vessel 8, it may be formed by a configuration different from that of the reaction vessel 8.

  Similarly, the guide wall 8s is provided with the SiC source source 18 composed of a solid containing a material that is a source of SiC in a region that is lower in temperature than the growth surface of the SiC single crystal 6. The SiC raw material source 18 may be provided at a location different from the flange portion 8t. In addition, as in the first and second embodiments, the SiC single crystal manufacturing apparatus 1 having a structure in which exhaust gas flows out from above also places the SiC source source 18 downstream of the source gas 3 a from the growth surface of the SiC single crystal 6. By arranging on the side, the above effects can be obtained more. In this case, the above effect can be obtained even if the structure is provided with only the SiC raw material source 18 without providing the gas outlet 8c and the auxiliary gas supply source 14.

DESCRIPTION OF SYMBOLS 1 SiC single crystal manufacturing apparatus 3a Source gas 5 Seed crystal 6 SiC single crystal 7 Vacuum container 8 Heating container 9 Base 12, 13 1st, 2nd heating apparatus

Claims (8)

A pedestal (9) is disposed in a cylindrical reaction vessel (8) that constitutes a reaction chamber for growing a silicon carbide single crystal (6), and a seed constituted by a silicon carbide single crystal substrate with respect to the pedestal. In the silicon carbide single crystal manufacturing apparatus in which the silicon carbide single crystal is grown on the surface of the seed crystal by disposing the crystal (5) and supplying the silicon carbide source gas (3a) from below the seed crystal.
Gas supply means (8c) for supplying a gas containing at least one of Si and C as a raw material of silicon carbide to the downstream side of the flow path of the raw material gas from the growth surface of the silicon carbide single crystal in the reaction vessel. 14, 18) is provided,
The gas supply means includes
An auxiliary gas supply source (14) for supplying an auxiliary gas (15) containing a material to be a raw material of silicon carbide;
A first gas jetting port (8c) for jetting the auxiliary gas is formed on the downstream side of the flow path of the source gas from the growth surface of the silicon carbide single crystal in the reaction vessel. silicon carbide single crystal manufacturing apparatus characterized by. Silicon carbide single crystal manufacturing apparatus according to claim 1, wherein the first gas ejection ports are formed on the inner wall surface of the reaction vessel. Unreacted gas in the source gas is discharged as exhaust gas above the growth surface of the silicon carbide single crystal,
3. The silicon carbide single crystal manufacturing apparatus according to claim 2 , wherein the first gas ejection port ejects the auxiliary gas toward a side surface of the pedestal. 4. The silicon carbide single crystal manufacturing apparatus according to claim 3 , wherein the first gas ejection port is directed obliquely upward toward the inside of the reaction vessel. 5. The reaction vessel has an inlet (2) for introducing the source gas formed at a central position on the bottom surface of the reaction vessel, and a guide wall for guiding the source gas toward the pedestal surrounding the inlet. (8s) and an outlet (4) formed outside the guide wall of the bottom surface of the reaction vessel, and the flow of the source gas formed at the center position of the bottom surface of the reaction vessel In addition to being introduced from the inlet, the unreacted gas in the source gas is folded downward from the growth surface of the silicon carbide single crystal and discharged as exhaust gas below the growth surface of the silicon carbide single crystal. Is configured as
3. The silicon carbide single crystal manufacturing apparatus according to claim 2 , wherein the first gas ejection port ejects the auxiliary gas toward the guide wall . 4. Than said first gas ejection ports, according to claim 1, wherein the downstream side of the flow path of the raw material gas, wherein the second gas port (8j) is formed for ejecting an inert gas (16) The silicon carbide single crystal manufacturing apparatus according to any one of 1 to 5 . A solid silicon carbide source source (18) for generating a gas containing at least one of Si and C as a silicon carbide source is provided downstream of the flow path of the source gas in the reaction vessel. The silicon carbide single crystal manufacturing apparatus according to any one of claims 1 to 6 . The silicon carbide single crystal manufacturing apparatus according to claim 7 , wherein the silicon carbide raw material source is a powdery solid.

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