Epitaxial growth apparatus for silicon carbide semiconductor

Abstract

To provide an epitaxial growth apparatus for a SiC semiconductor capable of suppressing the generation of V-Si within a nozzle.SOLUTION: An epitaxial growth apparatus for a SiC semiconductor comprises: a chamber 1 having an internal space; a susceptor 2 that is disposed within the chamber 1 and constitutes a mounting surface for a SiC semiconductor substrate 9; a reaction vessel 3 that surrounds the susceptor 2 and constitutes a growth space 11 in which a SiC semiconductor layer 10 is epitaxially grown above the SiC semiconductor substrate 9; a first gas nozzle 4 that introduces a source gas for SiC into the reaction vessel 3; a second gas nozzle 5 that introduces a dopant gas containing V to a position separated from the first gas nozzle 4; a gas discharge pipe 6 that discharges a gas flowing out from the growth space 11 from the chamber 1; and a heating device 7 that heats the reaction vessel 3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an epitaxial growth apparatus capable of epitaxially growing silicon carbide (hereinafter referred to as SiC) semiconductor. [Background technology]

[0002] Patent Document 1 discloses an epitaxial growth apparatus for SiC semiconductor layers that can be doped with both p-type and n-type impurities. This epitaxial growth apparatus includes a reaction vessel that forms a growth space and first to fourth supply paths that supply various gases into the reaction vessel. The first supply path supplies a Si source gas containing Si (silicon). The second supply path supplies a C source gas containing C (carbon). The third supply path supplies a dopant gas of an n-type impurity. The fourth supply path supplies a dopant gas of a p-type impurity. Each supply path is equipped with an MFC (mass flow controller), making it possible to control the flow rate of gas flowing through each path. The first to fourth supply paths are combined just before a gas nozzle that serves as a gas introduction pipe for the reaction vessel, and various gases are supplied into the reaction vessel through a single gas nozzle. This allows an SiC semiconductor layer doped with n-type impurities or p-type impurities to be epitaxially grown on the SiC semiconductor substrate placed in the reaction chamber. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-187113 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when depositing a V (vanadium)-doped SiC semiconductor layer, it was confirmed that V-Si products are formed inside the nozzle that introduces gas from the supply path into the growth space, causing the nozzle to become clogged. Specifically, to prevent nozzle clogging due to SiC growth, the nozzle outlet temperature needs to be kept below 1400°C, but V doping below 1400°C results in the formation of V-Si.

[0005] An object of the present disclosure is to provide an epitaxial growth apparatus for SiC semiconductors that can suppress the generation of V-Si within the nozzle. [Means for solving the problem]

[0006] An epitaxial growth apparatus according to one aspect of the present disclosure comprises: A chamber (1) having an internal space; a susceptor (2) disposed in the chamber and constituting a mounting surface for a SiC semiconductor substrate (9); a reaction vessel (3) surrounding the susceptor and constituting a growth space (11) for epitaxially growing a SiC semiconductor layer (10) on the SiC semiconductor substrate; a first gas nozzle (4) for introducing a raw material gas of SiC into the reaction vessel; a second gas nozzle (5) disposed at a position distant from the first gas nozzle and configured to introduce a dopant gas containing V into the reaction vessel; a gas exhaust pipe (6) for exhausting gases flowing out of the growth space from the chamber; and a heating device (7) for heating the reaction vessel.

[0007] In an epitaxial growth apparatus configured in this manner, the source gas and the V dopant gas are introduced from separate nozzles, so that V-Si can be prevented from being generated at the gas outlets of the first gas nozzle and the second gas nozzle even if their temperatures are below 1400°C. Therefore, when epitaxially growing a SiC semiconductor layer, it is possible to prevent the gas outlets of the first gas nozzle and the second gas nozzle from being blocked by V-Si products.

[0008] The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and the specific components described in the embodiments described below. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view of an epitaxial growth apparatus according to a first embodiment of the present disclosure. [Figure 2] FIG. 4 is a cross-sectional view of an epitaxial growth apparatus according to a second embodiment of the present disclosure. [Figure 3] FIG. 10 is a cross-sectional view of an epitaxial growth apparatus according to a third embodiment of the present disclosure. [Figure 4] FIG. 10 is a cross-sectional view of an epitaxial growth apparatus according to a fourth embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In the following, including other embodiments described below, identical or equivalent parts will be denoted by the same reference numerals.

[0011] (First embodiment) An epitaxial growth apparatus for a SiC semiconductor according to a first embodiment of the present invention will be described with reference to FIG.

[0012] The epitaxial growth apparatus shown in FIG. 1 includes a chamber 1, a susceptor 2, a reaction vessel 3, a first gas nozzle 4, a second gas nozzle 5, a gas exhaust pipe 6, a heating device 7, a cooling unit 8, etc., and epitaxially grows a SiC semiconductor layer 10 on the surface of a SiC semiconductor substrate 9.

[0013] The chamber 1 is hollow and has a top surface 1a, a bottom surface 1b, and side surfaces 1c, and the susceptor 2, reaction vessel 3, etc. are disposed in the internal space. In this embodiment, the chamber 1 has a generally cylindrical outer shape, with the top surface 1a and bottom surface 1b being circular and the side surfaces 1c being cylindrical. The chamber 1 may be made of any material that can withstand the temperatures transmitted during epitaxial growth. For example, the chamber 1 is made of a metal such as stainless steel.

[0014] An opening 1aa and an opening 1ab are formed in the top surface 1a at positions spaced apart from each other. A first gas nozzle 4 is disposed in the opening 1aa, and a second gas nozzle 5 is disposed in the opening 1ab. An opening 1ba is also formed in the bottom surface 1b around the susceptor 2, and a gas exhaust pipe 6 is disposed therein. In FIG. 1, the opening 1ba is shown on both radial sides of the susceptor 2, but it may be provided at multiple locations equally spaced circumferentially around the susceptor 2, or at only one location.

[0015] The susceptor 2 constitutes a mounting surface on which a SiC semiconductor substrate 9 is mounted for epitaxial growth. In this embodiment, the susceptor 2 is disposed at the center of the bottom surface of the chamber 1, and the SiC semiconductor substrate 9 is mounted on the upper surface of the susceptor 2 as the mounting surface. The susceptor 2 is rotated by a rotation mechanism (not shown) during epitaxial growth, with the normal direction to the surface of the SiC semiconductor substrate 9 as the central axis and the center of the SiC semiconductor substrate 9 as the center of rotation. This ensures uniformity in the impurity doping concentration and film thickness distribution of the grown SiC semiconductor layer 10. For example, the susceptor 2 may be made of graphite, graphite coated on its surface with a high-melting-point metal carbide such as TaC (tantalum carbide) or NbC (niobium carbide), or the entire susceptor may be made of a high-melting-point metal carbide. Note that the high-melting-point metal carbide referred to here means a metal carbide that does not melt even at the temperature (e.g., approximately 1600°C) used to grow the SiC semiconductor layer 10.

[0016] The reaction vessel 3 is a wall member that divides the internal space of the chamber 1 and forms a room into which gas is introduced. It is disposed so as to surround the periphery of the susceptor 2 and forms a growth space 11 in which epitaxial growth takes place. The reaction vessel 3 is made of graphite, or graphite whose surface is coated with a high-melting-point metal carbide such as TaC or NbC or SiC, or the entire reaction vessel 3 is made of a high-melting-point metal carbide. In this embodiment, the reaction vessel 3 is formed in a cylindrical shape that is slightly smaller than the side surface 1c of the chamber 1, and is disposed inside the side surface 1c of the chamber 1 with a space provided between it and the side surface 1c of the chamber 1.

[0017] A gap is provided between the inner wall surface of the reaction vessel 3 and the susceptor 2, and an opening 1ba and a gas exhaust pipe 6 are disposed in the gap. Therefore, the growth space 11 formed in the reaction vessel 3 is connected to the gas exhaust pipe 6 through the gap between the inner wall surface of the reaction vessel 3 and the susceptor 2.

[0018] The first gas nozzle 4 is a tubular member provided within an opening 1aa formed in the upper surface 1a of the chamber 1, and is made of, for example, SUS or graphite. The first gas nozzle 4 introduces a Si source gas, for example, a silane-based gas such as SiH4, and a C source gas, for example, a propane-based gas such as C3H8. Here, a carrier gas, for example, H2 (hydrogen), is introduced through the first gas nozzle 4 along with the Si source gas and the C source gas. Note that in this embodiment, the first gas nozzle 4 is a tubular member disposed within the opening 1aa in the upper surface 1a of the chamber 1, but the opening 1aa may also constitute the first gas nozzle 4.

[0019] The second gas nozzle 5 is also a tubular member provided within an opening 1ab formed in the upper surface 1a of the chamber 1, and is made of, for example, SUS or graphite. A dopant gas containing V, such as VCl4, is introduced through the second gas nozzle 5. Here, a carrier gas, such as H2, is introduced in addition to the V-containing dopant gas through the second gas nozzle 5. In this embodiment, the second gas nozzle 5 is a tubular member disposed within the opening 1ab in the upper surface 1a of the chamber 1, but the opening 1ab may also constitute the second gas nozzle 5.

[0020] Introducing a dopant gas containing V in this manner results in V being doped into SiC semiconductor layer 10. V has the effect of suppressing current degradation of a diode when a SiC semiconductor device including a diode is formed using SiC semiconductor substrate 9 on which SiC semiconductor layer 10 is formed.

[0021] For example, a SiC semiconductor device including a switching element such as a metal oxide semiconductor field effect transistor (MOSFET) can be constructed using a SiC semiconductor substrate 9 on which a SiC semiconductor layer 10 is formed. In this case, a built-in diode is formed. When this SiC semiconductor device is applied to an inverter circuit or the like and the built-in diode operates in bipolar mode due to reflux during switching, basal plane dislocations (hereinafter referred to as BPDs) may expand into Shockley stacking faults (hereinafter referred to as SSFs). That is, holes passing near BPDs recombine with electrons in the n-type layer, generating large recombination energy, causing the BPDs to expand into SSFs. SSFs occupy a larger area than BPDs and are prone to degrading the electrical characteristics of SiC semiconductor devices, i.e., causing current degradation of the diode. Therefore, it is desirable to suppress the expansion of BPDs into SSFs. V has the effect of suppressing this expansion.

[0022] The first gas nozzle 4 and the second gas nozzle 5 can be placed anywhere as long as they are spaced apart by a predetermined distance or more. Here, however, they are placed on either side of the center of the circular upper surface 1a in the radial direction, at positions spaced the same distance from the center.

[0023] The gas exhaust pipe 6 exhausts unnecessary gases from the chamber 1. In the present embodiment, the gas exhaust pipe 6 is provided on the bottom surface of the chamber 1, and is configured to exhaust unreacted gases of the Si raw material gas and the C raw material gas, carrier gas, and the like that have flowed out from the growth space 11.

[0024] The heating device 7 heats the reaction vessel 3 to raise the temperature of the growth space 11. The heating device 7 may be a device that performs heating by either a direct heating method or an induction heating method, but in the present embodiment, a device that performs heating by a direct heating method is used as the heating device 7. The reaction vessel 3 is heated by this heating device 7, and the Si source gas and the C source gas introduced into the growth space 11 are thermally decomposed to form an atmosphere in which epitaxial growth takes place.

[0025] The epitaxial growth apparatus further includes a cooling unit 8 that cools the first gas nozzle 4 and the second gas nozzle 5. In this embodiment, the cooling unit 8 is configured by incorporating a flow path through which cooling water 8a flows in the upper surface 1a of the chamber 1. The cooling unit 8 is disposed, for example, so as to surround the first gas nozzle 4 and the second gas nozzle 5 and also pass between the first gas nozzle 4 and the second gas nozzle 5, as long as the layout is such that the temperature in at least the vicinity of the first gas nozzle 4 is 1400°C or less.

[0026] The epitaxial growth apparatus for a SiC semiconductor according to this embodiment is configured as described above. In the epitaxial growth apparatus configured as described above, when epitaxially growing a SiC semiconductor layer 10, the reaction vessel 3 is heated by the heating device 7, and the SiC semiconductor substrate 9 is heated to, for example, 1600 to 1750°C. At this time, the gas outlets of the first gas nozzle 4 and the second gas nozzle 5 may be heated by radiant heat from the reaction vessel 3, the SiC semiconductor substrate 9, etc., but the temperature is kept below 1400°C, for example, in the range of 500 to 1200°C. This prevents the gas outlets of the first gas nozzle 4 and the second gas nozzle 5 from being clogged by SiC growth.

[0027] On the other hand, at temperatures of 1400°C or lower, at which V-Si may be generated, in this embodiment, the Si source gas and the C source gas are introduced through the first gas nozzle 4, and the V dopant gas is introduced through the second gas nozzle 5, which is separated from the first gas nozzle 4. In this way, because the Si source gas and the V dopant gas are introduced through separate gas nozzles, even if the gas outlets of the first gas nozzle 4 and the second gas nozzle 5 are at 1400°C or lower, generation of V-Si at the gas outlets can be suppressed.

[0028] Therefore, it is possible to prevent the gas outlets of the first gas nozzle 4 and the second gas nozzle 5 from being blocked by the V-Si product when epitaxially growing the SiC semiconductor layer 10. This makes it possible to stably grow the SiC semiconductor layer 10.

[0029] (Second embodiment) A second embodiment of the present disclosure will be described. This embodiment differs from the first embodiment in that a gas is introduced from the first gas nozzle 4 and the number of gas nozzles is increased. Since the other aspects are the same as those of the first embodiment, only the differences from the first embodiment will be described.

[0030] 2, in this embodiment, in addition to the Si source gas, the C source gas, and the carrier gas, HCl serving as an etching gas is introduced from the first gas nozzle 4. By introducing the etching gas in addition to the Si source gas and the C source gas, it is possible to further suppress the generation of SiC polycrystals and the like within the first gas nozzle 4.

[0031] Furthermore, in addition to the first gas nozzle 4 and the second gas nozzle 5, a third gas nozzle 20 is provided. The third gas nozzle 20 may be positioned arbitrarily, but here it is positioned between the first gas nozzle 4 and the second gas nozzle 5. In other words, the third gas nozzle 20 is positioned closest to the center of the upper surface 1a of the chamber 1, and the first gas nozzle 4 and the second gas nozzle 5 are positioned outside the third gas nozzle 20.

[0032] In addition to openings 1aa and 1ab, an opening 1ac is formed in the upper surface 1a of the chamber 1. The third gas nozzle 20 is a tubular member provided within the opening 1ac and is made of, for example, SUS or graphite. The third gas nozzle 20 introduces NH3 as an n-type dopant gas containing N, which serves as an n-type impurity. Here, a carrier gas, such as H2, is introduced through the third gas nozzle 20 together with NH3, which serves as the n-type dopant gas.

[0033] As described above, when an n-type dopant gas is introduced, a third gas nozzle 20 is provided in addition to the first gas nozzle 4 and the second gas nozzle 5, and the gas is introduced through the third gas nozzle 20. When NH is used as the n-type dopant gas, if the gas introduced through the first gas nozzle 4 contains Cl or if VCl containing Cl is used as the V dopant gas, NH may be generated in the gas nozzle, causing the gas nozzle to become clogged. However, in this embodiment, these gases are introduced through different gas nozzles, namely the first gas nozzle 4, the second gas nozzle 5, and the third gas nozzle 20, which are arranged separately from each other. Therefore, separating the first gas nozzle 4 from the second gas nozzle 5 not only prevents the generation of V-Si, but also prevents the generation of NH Cl by separating the third gas nozzle 20 from the first gas nozzle 4 and the second gas nozzle 5.

[0034] Therefore, it is possible to prevent the gas outlets of the gas nozzles from being clogged with V-Si products or NH4Cl when epitaxially growing the SiC semiconductor layer 10. This makes it possible to stably grow the SiC semiconductor layer 10.

[0035] Here, the case where HCl, which serves as an etching gas, is introduced has been described as an example of a case where the gas introduced from the first gas nozzle 4 contains Cl. However, there are other cases, such as when a chlorosilane, such as SiHCl, is used as the SiC source gas. Even when Cl is contained in either the gas introduced from the first gas nozzle 4 that introduces the Si source gas or the C source gas, i.e., the gas used to prepare the SiC source gas or the gas introduced together with the gas, it is effective to suppress the generation of NH4Cl. Furthermore, although the present embodiment has shown a case where Cl is contained in both the gas introduced from the first gas nozzle 4 and the second gas nozzle 5, it is preferable to suppress the generation of NH4Cl even when only one of the gases contains Cl.

[0036] (Third embodiment) A third embodiment of the present disclosure will now be described. This embodiment differs from the first and second embodiments in that the configuration of second gas nozzle 5 is modified. Since the remaining features are similar to those of the first and second embodiments, only the differences from the first and second embodiments will be described. Note that, as in the second embodiment, an epitaxial growth apparatus equipped with third gas nozzle 20 is used as an example to which the configuration of this embodiment is applied. However, the present invention may also be applied to an epitaxial growth apparatus that does not have third gas nozzle 20 as in the first embodiment.

[0037] As shown in FIG. 3 , in the epitaxial growth apparatus of this embodiment, the gas outlet of the second gas nozzle 5 is located lower than the gas outlets of the first gas nozzle 4 and the third gas nozzle 20, i.e., closer to the susceptor 2. In other words, the second gas nozzle 5 extends toward the high-temperature side. Preferably, the second gas nozzle 5 is located on the outer periphery of the upper surface 1 a, i.e., closer to the reaction vessel 3, so that the portion of the second gas nozzle 5 protruding from the upper surface 1 a is aligned with the inner wall surface of the reaction vessel 3. More preferably, the lower end of the second gas nozzle 5 is located near the portion of the reaction vessel 3 where the heating device 7 is located. For example, the lower end of the second gas nozzle 5 is located lower than the upper end of the heating device 7 so that the upper end of the heating device 7 and the gas outlet of the second gas nozzle 5 overlap when viewed horizontally.

[0038] This makes it possible to further separate the V dopant gas from the Si source gas. This further suppresses the generation of V-Si and the blockage of each gas nozzle with the V-Si product. Furthermore, extending the second gas nozzle 5, through which the V dopant gas is introduced, to the higher temperature side, and positioning the V and Si mixture at a higher temperature, further suppresses the generation of V-Si. In particular, the second gas nozzle 5 is positioned more outside than the third gas nozzle 20 and closer to the heating device 7, which makes it easier to heat the second gas nozzle 5 to a higher temperature.

[0039] (Fourth embodiment) A fourth embodiment of the present disclosure will be described. This embodiment differs from the third embodiment in that the gases introduced from the first gas nozzle 4 and the second gas nozzle 5 are mixed and introduced into the growth space 11. Since the remaining features are the same as the first and second embodiments, only the differences from the third embodiment will be described.

[0040] As shown in FIG. 4 , in this embodiment, the second gas nozzle 5 is disposed on the outer side of the first gas nozzle 4 and the third gas nozzle 20 on the upper surface 1 a of the chamber 1. In this embodiment, as in the third embodiment, the second gas nozzle 5 extends downward and is provided at multiple locations on the upper surface 1 a on the outer periphery of the first gas nozzle 4 and the third gas nozzle 20. A shower plate 30, which serves as a partition plate and has multiple holes 30 a, is provided below the gas outlets of the first gas nozzle 4 and the third gas nozzle 20, which are provided further inward. This forms a mixing space 31 above the growth space 11. In the mixing space 31, the Si source gas and the C source gas from the first gas nozzle 4 are mixed with the dopant gas containing an impurity element from the third gas nozzle 20 to produce a mixed gas. The mixed gas is introduced into the growth space 11 in a shower-like manner through the multiple holes 30 a in the shower plate 30, enabling each element to be supplied uniformly within the surface of the SiC semiconductor substrate 9.

[0041] By introducing the mixed gas into growth space 11 in this way, the thickness and carrier concentration of SiC semiconductor layer 10 can be made more uniform.

[0042] Generally, epitaxially grown films require high uniformity, such as thickness of ±10% and carrier concentration of ±15%. 14 cm -3 If the impurity concentration of V is too high, defects may occur, but if the impurity concentration is 1×10 16 cm -3 If the V impurity concentration is less than 1×10 14 cm-3 Greater than or equal to 1 x 10 16 cm -3 If the concentration is below this range, the effect of suppressing current degradation of the diode can be obtained while also suppressing defects. Since the setting range of such a V impurity concentration is wide and easily adjustable, there is no need to uniformly introduce the V-containing gas using the shower plate 30. Therefore, the V-containing gas can be introduced to a position with a higher gas outlet temperature without passing through the shower plate 30, while the Si raw material gas and the like can be uniformly introduced using the shower plate 30.

[0043] (Other embodiments) Although the present disclosure has been described based on the above-described embodiment, it is not limited to the embodiment and encompasses various modifications and modifications within the equivalent range. In addition, various combinations and forms, as well as other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

[0044] For example, the shapes of the chamber 1, susceptor 2, and reaction vessel 3, as well as the gas species introduced from each gas nozzle, described in the first to fourth embodiments are merely examples, and other shapes and gas species may be used. Furthermore, the second and third embodiments described above have been described with reference to an example in which an n-type dopant is introduced, i.e., the SiC semiconductor layer 10 is made n-type. This is also merely an example, and the epitaxial growth apparatus described in each of the above embodiments can be provided even when a p-type dopant is introduced to make the SiC semiconductor layer 10 p-type. Examples of p-type dopant gases include TMA (trimethylaluminum) gas and BH. Furthermore, although the first gas nozzle 4 is a single gas nozzle for introducing both the Si source gas and the C source gas, it may be divided into two gas nozzles, one for the Si source gas and one for the C source gas.

[0045] Furthermore, in each of the above embodiments, the reaction vessel 3 is provided in the chamber 1, and these are configured as separate entities. However, the chamber 1 itself may be configured as the reaction vessel 3. In other words, as long as the reaction vessel 3 surrounds the periphery of the susceptor 2 to form the growth space 11, the reaction vessel 3 may be configured as the chamber 1 itself or may be separate from the chamber 1. [Explanation of symbols]

[0046] 1...chamber, 1a...top surface, 1b...bottom surface, 1c...side surface, 1aa, 1ab, 1ac...opening, 1ba...opening, 2...susceptor, 3...reaction vessel, 4...first gas nozzle, 5...second gas nozzle, 6...gas exhaust pipe, 7...heating device, 8...cooling section, 9...SiC semiconductor substrate, 10...SiC semiconductor layer, 11...growth space, 20...third gas nozzle, 30...shower plate, 30a...hole, 31...mixing space

Claims

1. A chamber (1) having an internal space; a susceptor (2) disposed in the chamber and constituting a mounting surface for a silicon carbide semiconductor substrate (9); a reaction vessel (3) surrounding the periphery of the susceptor and constituting a growth space (11) for epitaxially growing a silicon carbide semiconductor layer (10) on the silicon carbide semiconductor substrate; a first gas nozzle (4) for introducing a silicon carbide raw material gas into the reaction vessel; a second gas nozzle (5) disposed at a position distant from the first gas nozzle and configured to introduce a dopant gas containing vanadium into the reaction vessel; a gas exhaust pipe (6) for exhausting gases flowing out of the growth space from the chamber; and a heating device (7) for heating the reaction vessel.

2. 2. The epitaxial growth apparatus according to claim 1, wherein a gas outlet of the second gas nozzle extends closer to the susceptor than the first gas nozzle.

3. 3. The epitaxial growth apparatus according to claim 1, further comprising: a third gas nozzle (20) arranged at a position spaced apart from the first gas nozzle and the second gas nozzle, and configured to introduce a dopant gas containing an element that becomes an n-type or p-type impurity for the silicon carbide semiconductor layer.

4. The chamber has a hollow shape having a top surface (1a), a bottom surface (1b), and a side surface (1c), the first gas nozzle, the second gas nozzle, and the third gas nozzle are disposed at different positions on the top surface of the chamber; 4. The epitaxial growth apparatus according to claim 3, wherein the second gas nozzle is disposed at a position on the upper surface that is more outer than the third gas nozzle.

5. the second gas nozzle is disposed on the upper surface outward of the first gas nozzle and the third gas nozzle; a shower plate (30) having a plurality of holes (30a) formed below the gas outlet of the first gas nozzle and the gas outlet of the third gas nozzle, the shower plate (30) serving as a partition plate constituting a mixing space (31) above the growth space; the source gas introduced from the first gas nozzle and the dopant gas containing the element to be the impurity introduced from the third gas nozzle are mixed in the mixing space and then introduced into the growth space through the plurality of holes; 5. The epitaxial growth apparatus according to claim 4, wherein the vanadium-containing dopant gas introduced from the second gas nozzle is introduced into the growth space without passing through the mixing space.

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