JP2007250946A - Apparatus for manufacturing group iii nitride crystal, lamination structure of group iii nitride crystal and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for manufacturing composite group III nitride and provided with functions of a MOCVD apparatus and an HVPE apparatus. <P>SOLUTION: The manufacturing apparatus 10 is provided with: a supply tube 14a for supplying TMA into a reaction pipe 11; a supply tube 14b for supplying HCl gas to a boat 15 wherein the HCl gas is reacted with Al to produce AlCl<SB>x</SB>gas, which is supplied into the reaction pipe 11; a supply tube 14c for supplying NH<SB>3</SB>gas into the reaction pipe 11; and a supply tube 14d for supplying carrier gas into the reaction pipe 11. Crystal growth in a MOCVD mode can be executed by stopping the supply of HCI gas, supplying the TMA and the NH<SB>3</SB>to the reaction pipe 11, and carrying out heating by a second heater 17 only. Crystal growth in an HVPE mode can be executed by stopping supply of the TMA, supplying the HCl and the NH<SB>3</SB>, and carrying out heating by a first heater 16 and the second heater 17. The crystal growth on one substrate in both the modes can be switchingly executed by properly switching the gas supply modes and the heating modes. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an apparatus for producing a group III nitride crystal, and more particularly to an apparatus for epitaxially growing a group III nitride film.

    Group III nitride crystals are used as a material constituting semiconductor elements such as photonic devices and electronic devices.

  As a method for producing a thick film of Group III nitride crystal (Group III nitride thick film), a growth method such as LPE (Liquid Phase Epitaxy), HVPE (Hydride Vapor Phase Epitaxy), or sublimation method on a predetermined base substrate There is known a method of epitaxially forming a group III nitride crystal by using (see, for example, Patent Document 1). There is a mode in which a single crystal base material such as sapphire or SiC is used as the base substrate, but a group III nitride crystal is not more than about 10 μm on such a single crystal base material (the warpage caused by the difference in thermal expansion coefficient). A so-called epitaxial substrate (also referred to as a template substrate) formed epitaxially (to the extent that it does not occur) may be used (see, for example, Patent Document 2). The epitaxial substrate is usually a group III nitridation that is the same or different from the thick film formed on the thin film forming method such as MOCVD (metal organic chemical vapor deposition) or MBE (molecular beam epitaxy). It can be obtained by epitaxially forming a physical crystal to a maximum of about 10 μm (to the extent that warpage due to a difference in thermal expansion coefficient does not occur).

JP 2005-252248 A JP-A-2005-223126

  When a group III nitride crystal is formed by using the HVPE method, there is no high-quality single crystal for homoepitaxial growth. Therefore, it is necessary to use an epitaxial substrate on which a base film of the same type of crystal is formed as the base substrate.

  Conventionally, after an epitaxial substrate is formed by forming a base film on a predetermined base material in an MOCVD apparatus or MBE apparatus, the epitaxial substrate is used for crystal growth in an HVPE apparatus. However, the manufacturing method based on the use of two different types of devices is a problem in reducing the manufacturing cost.

  Further, while the HVPE method has an advantage of a high growth rate, it has a drawback that it is difficult to control the growth rate with high accuracy because it is difficult to control the initial nucleation. Therefore, it is difficult to apply the HVPE method when it is desired to insert a relatively thin intermediate layer of about several tens of nanometers into the thick film.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an apparatus for producing a group III nitride crystal capable of combining crystal growth by the HVPE method and crystal growth by the MOCVD method.

  In order to solve the above problems, the invention of claim 1 is an apparatus for producing a group III nitride crystal by performing a gas phase reaction between a group III element-containing gas and a nitrogen element-containing gas in a reaction tube, A first group III element supply means for supplying an organic metal gas containing a group III element as a group element-containing gas into the reaction tube, and reacting the group III element metal and hydrogen halide to generate a halide gas. A second group III element supply means for supplying the halide gas as the group III element-containing gas into the reaction tube; and a nitrogen element supply means for supplying the nitrogen element-containing gas into the reaction tube. When producing a group III nitride crystal, the first and second group III element supply means are selectively used to supply the group III element-containing gas.

  The invention according to claim 2 is the manufacturing apparatus according to claim 1, wherein the gas supply ports of the first and second group III element supply means and the nitrogen element supply means are provided in the reaction tube. It is characterized by being provided independently of each other in the vicinity of the reaction region.

  The invention according to claim 3 is the manufacturing apparatus according to claim 1 or 2, wherein ammonia gas is used as the nitrogen element-containing gas.

  According to a fourth aspect of the present invention, in the method for manufacturing a laminated structure of group III nitride crystals, the first group III element is supplied using the manufacturing apparatus according to any one of the first to third aspects. A first forming step of forming a first group III nitride layer by performing a gas phase reaction between the group III element-containing gas supplied by the means and the nitrogen element containing gas; and the second group III element supplying means And a second forming step of forming a second group III nitride layer by performing a gas phase reaction between the group III element-containing gas and the nitrogen element-containing gas supplied by the step, a predetermined number of times. To do.

  According to a fifth aspect of the present invention, there is provided a laminated structure of a group III nitride crystal using the first group III element supply means by using the manufacturing apparatus according to any one of the first to third aspects. A layer formed by a gas phase reaction between the supplied Group III element-containing gas and the nitrogen element-containing gas; the Group III element-containing gas supplied by the second Group III element supply means; and the nitrogen And a layer formed by gas-phase reaction with an element-containing gas.

  According to the first to third aspects of the invention, a composite group III nitride manufacturing apparatus having both the function of the MOCVD apparatus and the function of the HVPE apparatus is realized. According to such a manufacturing apparatus, when crystal growth on one substrate is performed by appropriately switching between a gas supply mode and a heating mode, crystal growth by MOCVD method and crystal growth by HVPE method are appropriately performed. Since it can be performed while switching, crystal growth with a higher degree of freedom is possible by taking advantage of the advantages of both methods.

  According to the inventions of claim 4 and claim 5, by appropriately switching between crystal growth by the MOCVD method and crystal growth by the HVPE method, when using only one of the methods, or depending on each method It is possible to obtain a layered structure of group III nitride crystals that is superior in cost and quality as compared with the case where crystal growth is performed by another apparatus.

<First Embodiment>
<Device configuration>
FIG. 1 is a schematic cross-sectional view conceptually showing the structure of a group III nitride crystal production apparatus 10 according to the present embodiment. The production apparatus 10 includes a reaction tube 11 made of, for example, quartz or SUS stainless steel having a longitudinal direction in a substantially horizontal direction. Inside the reaction tube 11, a susceptor 12 having a substantially horizontal mounting surface is provided. In a state where the base substrate 13 is mounted on the mounting surface of the susceptor 12, a predetermined gas is supplied from a supply system 14 provided on one end side of the reaction tube 11, and a predetermined gas phase is formed in a space above the base substrate 13. By causing the reaction, a group III nitride crystal can be epitaxially formed on the base substrate 13. In the following description, the case where AlN is produced as a group III nitride crystal is described as an example, but the production apparatus 10 is a group III containing other group III elements (B, Ga, In, etc.). The present invention is also applicable when producing a nitride crystal.

  In the present embodiment, the supply system 14 includes four supply pipes 14a, 14b, 14c, and 14d. The supply pipes 14 a, 14 b, 14 c, and 14 d are all provided so that the tip portion (supply port) reaches the vicinity of the susceptor 12. Through these supply pipes 14 a, 14 b, 14 c, and 14 d, a predetermined gas supplied from a predetermined supply source (not shown) is supplied to the vicinity of the susceptor 12 inside the reaction pipe 11.

TMA (trimethylaluminum) is supplied from the supply pipe 14a together with a predetermined carrier gas (for example, N ₂ gas). The gas containing TMA is referred to as a first gas g1.

  HCl is supplied together with the carrier gas from the supply pipe 14b. This gas containing HCl is referred to as a second gas g2. In the middle of the supply pipe 14b for supplying the second gas g2, a boat 15 for placing metal Al powder is provided.

NH ₃ is supplied from the supply pipe 14c together with the carrier gas. The gas containing NH ₃ is referred to as a third gas g3.

  Only the carrier gas is supplied from the supply pipe 14d. This gas will be referred to as a fourth gas g4.

  The outer periphery of the reaction tube 11 is provided with a first heater 16 for heating at least a portion including the boat 15 in the supply system 14 from the outside of the reaction tube 11 in order to heat the reaction region of HCl and Al. ing. The first heater 16 is a resistance heater. Furthermore, a second heater 17 for heating the base substrate 13 placed on the susceptor 12 is provided in order to perform epitaxial growth on the base substrate 13. The second heater 17 is an RF heater.

  An exhaust system 18 for exhausting from the inside of the reaction tube 11 is also provided.

  In the manufacturing apparatus 10 having such a configuration, the gas from the supply system 14 includes the selection of a supply pipe for supplying gas, the flow control of the supplied gas, and the pressure control in the reaction pipe by a control means (not shown). By appropriately performing the control of the supply mode and the control of the heating mode of the first heater and the second heater 17, it is possible to produce a desired group III nitride crystal.

In particular, the supply of the second gas g2 from the supply pipe 14b is stopped, the first gas g1 and the third gas g3, or further the fourth gas g4 is supplied at an appropriate flow rate, and the first heater 16 does not perform heating. When heating the base substrate 13 by the second heater 17, a gas phase reaction between TMA in the first gas g 1 and NH ₃ in the third gas g ₃ occurs above the base substrate 13, and III AlN, which is a group nitride, is deposited on the base substrate 13. That is, crystal growth by the MOCVD method is realized. Therefore, it can be said that the manufacturing apparatus 10 has a function as an MOCVD apparatus. Thus, the usage mode for realizing crystal growth by the MOCVD method is referred to as an MOCVD mode.

Further, the supply of the first gas g1 from the supply pipe 14a is stopped, the second gas g2 and the third gas g3, or further the fourth gas g4 is supplied at an appropriate flow rate, and the vicinity of the boat 15 by the first heater 16 When the heating of the base substrate 13 by the second heater 17 and the heating of the base substrate 13 are both performed, the HCl in the second gas g2 and the metal Al powder placed on the boat 15 are supplied inside the supply pipe 14b. A gas phase reaction between AlCl _x generated by the reaction and NH ₃ in the third gas g3 supplied from the supply pipe 14c occurs above the base substrate 13, and AlN which is a group III nitride is formed on the base substrate 13. It will be deposited. That is, crystal growth by the HVPE method is realized. Therefore, it can be said that the manufacturing apparatus 10 has a function as an HVPE apparatus. Thus, a usage mode for realizing crystal growth by the HVPE method is referred to as an HVPE mode.

  Therefore, in the manufacturing apparatus 10 according to the present embodiment, after the base substrate 13 is placed, the crystal growth by the MOCVD method and the crystal growth by the HVPE method are the same by switching between the MOCVD mode and the HVPE mode. Can be carried out continuously in the apparatus. This makes it possible to use Group III nitride crystals (strictly speaking, the stacked layers) that are superior in terms of cost or quality compared to the case where only one of the methods is used or the crystal growth by each method is performed by another apparatus. Structure) can be obtained.

  For example, first in the MOCVD mode, 0.5 μm on the base substrate 13 such as sapphire, SiC, MgO, BAlGaInN (a group III nitride including at least one of B, Al, Ga, and In). Crystal growth in such a manner that an AlN base film having a thickness is epitaxially formed, followed by annealing, and an AlN thick film crystal having a thickness of 200 μm is epitaxially formed on the AlN base film in an HVPE mode. It becomes possible.

  In this case, the former AlN base film is not heated by the first heater 16, and the base substrate 13 is heated to 1200 ° C. by the second heater 17 while the first gas g 1, the third gas g 3, This is realized by supplying 4 gases g4 so that the pressure in the reaction tube is 20 Torr. In the latter thick film crystal growth, after the formation of the AlN base film, the supply of the first gas g1 is stopped, the supply system 14 is heated to 550 ° C. by the first heater 16, and the base substrate 13 is heated by the second heater 17. This is realized by heating to 1500 ° C. and supplying the third gas g3 and the fourth gas g4 so that the pressure in the reaction tube becomes 40 Torr.

  Alternatively, the intermediate layer can be formed with high accuracy by interposing crystal growth in the MOCVD mode while the thick film is being formed in the HVPE mode.

  As described above, in the present embodiment, a composite group III nitride fabrication apparatus having both the function of the MOCVD apparatus and the function of the HVPE apparatus is realized. According to such a manufacturing apparatus, when crystal growth on one substrate is performed by appropriately switching between a gas supply mode and a heating mode, crystal growth by MOCVD method and crystal growth by HVPE method are appropriately performed. Since it can be performed while switching, crystal growth with a higher degree of freedom is possible by taking advantage of the advantages of both methods.

<Second Embodiment>
The configuration of the composite group III nitride manufacturing apparatus that has both the function of the MOCVD apparatus and the function of the HVPE apparatus is not limited to that shown in the first embodiment. In this embodiment mode, manufacturing apparatuses having different configuration modes are described.

  FIG. 2 is a schematic cross-sectional view conceptually showing the structure of the Group III nitride crystal production apparatus 20 according to the present embodiment. In addition, about the component which has the effect similar to the production apparatus 10 which concerns on 1st Embodiment in the production apparatus 20, the code | symbol same as FIG. 1 is attached | subjected and the description is abbreviate | omitted.

  The manufacturing apparatus 20 illustrated in FIG. 2 includes a supply system 24 having a configuration different from the supply system 14 according to the manufacturing apparatus 10. The supply system 24 includes two supply pipes 24a and 24b, and the first gas g1 is supplied from the supply pipe 24a and the second gas g2 is supplied from the supply pipe 24b. Since both the supply pipes 24a and 24b are provided so that the tip portions (supply ports) reach the vicinity of the susceptor 12, both the first gas g1 and the second gas g2 are provided in the reaction tube 11. Each is supplied to the vicinity of the internal susceptor 12. As in the first embodiment, a boat 15 for placing metal Al powder is provided in the middle of the supply pipe 24b for supplying the second gas g2.

  In the supply system 24, the third gas g3 is supplied to the vicinity of the susceptor 12 through the outer peripheral parts of the supply pipes 24a and 24b (upper and lower parts of the supply pipes 24a and 24b in FIG. 2). Yes.

  Also in the manufacturing apparatus 20 having such a configuration, similarly to the manufacturing apparatus 10, the control of the gas supply mode from the supply system 24 by the control means (not shown) and the heating mode of the first heater 16 and the second heater 17 are performed. By appropriately performing the control, it is possible to produce a desired group III nitride crystal.

  In particular, the supply of the second gas g2 from the supply pipe 24b is stopped, the first gas g1 and the third gas g3 are supplied at appropriate flow rates, the first heater 16 is not heated, and the second heater 17 is replaced with the base substrate. By heating 13, it becomes possible to use the MOCVD mode.

  Further, the supply of the first gas g1 from the supply pipe 24a is stopped, the second gas g2 and the third gas g3 are supplied at appropriate flow rates, and the heating in the vicinity of the boat 15 by the first heater 16 and the second heater 17 are performed. By using any heating of the base substrate 13 by the above, it is possible to use in the HVPE mode.

  Therefore, similarly to the manufacturing apparatus 10 according to the first embodiment, the manufacturing apparatus 20 according to the present embodiment also manufactures a composite group III nitride having both the function of the MOCVD apparatus and the function of the HVPE apparatus. In the case of crystal growth on a single substrate, it is possible to switch between crystal growth in the MOCVD mode and crystal growth in the HVPE mode as appropriate.

  As a result, for example, as exemplified in the first embodiment, crystal growth in a mode in which AlN is grown in the HVPE mode on the AlN base film manufactured in the MOCVD mode is set with the same conditions. And can be done.

Since the manufacturing apparatus 20 includes the supply system 24 having the above-described configuration, when crystal growth is performed in the HVPE mode, the third gas is provided above the susceptor 12 so as to wrap AlCl _x generated by the reaction in the supply pipe 24b. g3 will be supplied. When the reaction tube is made of quartz, there is a possibility that the reaction tube 11 is generally corroded when AlCl _x having high reactivity with quartz touches the inner wall surface of the reaction tube 11. Since the gas is supplied in the above-described manner, AlCl _x preferentially reacts with NH ₃ contained in the third gas g3 supplied to the surroundings. Therefore, even if the reaction tube 11 is made of quartz, it can be said that the possibility of corrosion is sufficiently suppressed.

  As described above, also in the present embodiment, a composite group III nitride production apparatus having both the function of the MOCVD apparatus and the function of the HVPE apparatus is realized. According to such a manufacturing apparatus, when crystal growth on one substrate is performed by appropriately switching between a gas supply mode and a heating mode, crystal growth by MOCVD method and crystal growth by HVPE method are appropriately performed. Since it can be performed while switching, crystal growth with a higher degree of freedom is possible by taking advantage of the advantages of both methods. In addition, the manufacturing apparatus according to the present embodiment is configured so that the corrosion of the reaction tube is further suppressed.

<Third Embodiment>
In the present embodiment, a further different configuration aspect of a composite group III nitride production apparatus having both the function of an MOCVD apparatus and the function of an HVPE apparatus will be described.

  FIG. 3 is a schematic cross-sectional view conceptually showing the structure of a Group III nitride crystal production apparatus 30 according to the present embodiment. In addition, about the component which has the effect similar to the production apparatus 10 which concerns on 1st Embodiment in the production apparatus 30, the code | symbol same as FIG. 1 is attached | subjected and the description is abbreviate | omitted.

  The production apparatus 30 shown in FIG. 3 is different from the production apparatus 10 according to the first embodiment in the configuration related to heating of the gas supplied from the supply system to the reaction tube. The production apparatus 30 includes a supply system 34 including three supply pipes 34a, 34b, and 34c. All of these three supply pipes 34a, 34b, and 34c are provided so that a tip end portion (supply port) is located at one end of a reaction tube 31 having a longitudinal direction in a substantially horizontal direction. The first gas g1 is supplied from the supply pipe 34a, the second gas g2 is supplied from the supply pipe 34b, and the third gas g3 is supplied from the supply pipe 34c. Further, in the reaction tube 31, the susceptor 12 having a substantially horizontal mounting surface is provided so that the supply ports of the supply tubes 34a, 34b, and 34c are located in the vicinity. As a result, all of the first gas g1, the second gas g2, and the third gas g3 are supplied to the vicinity of the susceptor 12, respectively.

Similarly to the first embodiment, a boat 15 for placing metal Al powder is provided in the middle of the supply pipe 34b for supplying the second gas g2. On the other hand, the first heater 16 is provided on the outer periphery of the reaction tube 11 in the first embodiment, but in the present embodiment, instead, the first heater 36 is provided only on the outer peripheral portion of the supply tube 34b. Is provided. In addition, the first heater 36 includes two heaters, an upstream heater 36a and a downstream heater 36b. The upstream heater 36a is provided to resistance-heat at least a portion including the boat 15 in the supply pipe 34b from the outside of the supply pipe 34b in order to heat the reaction region of HCl and Al. The downstream heater 36b resistance-heats a portion of the supply pipe 34b downstream of the heating portion of the upstream heater 36a from the outside in order to suppress precipitation of AlCl _x generated by the reaction in the upstream portion. It is provided. The heating temperatures of the upstream heater 36a and the downstream heater 36b can be adjusted independently. Therefore, heating can be performed under optimum temperature conditions for each.

  Also in the manufacturing apparatus 30 having such a configuration, similarly to the manufacturing apparatus 10, the control of the gas supply mode from the supply system 34 by the control means (not shown) and the heating mode of the first heater 36 and the second heater 17 are performed. By appropriately performing the control, it is possible to produce a desired group III nitride crystal.

  In particular, the supply of the second gas g2 from the supply pipe 34b is stopped, the first gas g1 and the third gas g3 are supplied at appropriate flow rates, the first heater 36 is not heated, and the second heater 17 is not connected to the base substrate. By heating 13, it becomes possible to use the MOCVD mode.

  Further, the supply of the first gas g1 from the supply pipe 34a is stopped, the second gas g2 and the third gas g3 are supplied at appropriate flow rates, the supply pipe 34b is heated by the first heater 36, and the second heater 17 is supplied. By performing any heating of the base substrate 13, use in the HVPE mode is possible.

  Therefore, similarly to the manufacturing apparatus 30 according to the first embodiment, the manufacturing apparatus 30 according to the present embodiment also manufactures a composite group III nitride having both the function of the MOCVD apparatus and the function of the HVPE apparatus. In the case of crystal growth on a single substrate, it is possible to switch between crystal growth in the MOCVD mode and crystal growth in the HVPE mode as appropriate.

  In particular, in the case of the HVPE mode, the heating temperature of the upstream heater 36a and the downstream heater 36b constituting the first heater 36 can be made different, so that more effective temperature conditions can be set for reaction generation. It has become. For example, when AlN is grown in the HVPE mode on the AlN base film manufactured in the MOCVD mode as exemplified in the first embodiment, the heating temperature of the upstream heater 36a is set to the first embodiment. The heating temperature of the downstream heater 36b is set to 200 ° C. while the heating temperature is set to 550 ° C. which is the same as the heating temperature of the first heater.

  Alternatively, in addition, in the manufacturing apparatus 30 according to the present embodiment, it is possible to perform mixed crystal growth by the MOCVD method and crystal growth by the HVPE method. Such a usage mode for realizing the crystal growth will be referred to as a mixed mode. In the mixing mode, all of the first gas g 1, the second gas g 2, and the third gas g 3 are supplied from the supply system 34 at appropriate flow rates, the heating of the supply pipe 34 b by the first heater 36, and the base by the second heater 17. This is realized by performing any heating of the substrate 13. According to the mixed mode, by appropriately controlling the supply balance between the first gas g1 and the second gas g2, it is possible to achieve accurate crystal growth while ensuring a growth rate. In this case, it is possible to form AlGaN in which the first gas g1 is TMG-containing gas and the mixed crystal ratio is accurately controlled.

  Note that it is not impossible to perform processing corresponding to this mixed mode using the manufacturing apparatuses 10 and 20 according to the first and second embodiments. However, both manufacturing apparatuses include TMA. Since the first gas g1 is heated by the first heater 16, depending on the heating conditions of the first heater 16, TMA is decomposed and generation of side reactants unrelated to the generation of group III nitride, It should be noted that precipitation can occur. On the other hand, in the manufacturing apparatus 30 according to the present embodiment, only the supply pipe 34b that supplies the second gas g2 containing HCl in the supply system 34 is heated. Will not occur. That is, it can be said that the manufacturing apparatus 30 has a configuration suitable for crystal growth in the mixed mode.

  As described above, also in the present embodiment, a composite group III nitride production apparatus having both the function of the MOCVD apparatus and the function of the HVPE apparatus is realized. According to such a manufacturing apparatus, when crystal growth on one substrate is performed by appropriately switching between a gas supply mode and a heating mode, crystal growth by MOCVD method and crystal growth by HVPE method are appropriately performed. This can be done while switching. In addition, it is a suitable apparatus for simultaneously performing crystal growth by the MOCVD method and crystal growth by the HVPE method. Thereby, crystal growth with a higher degree of freedom than in the first and second embodiments is possible.

<Fourth embodiment>
Also in the present embodiment, a further different configuration aspect of the composite group III nitride manufacturing apparatus having both the function of the MOCVD apparatus and the function of the HVPE apparatus will be described.

  FIG. 4 is a schematic cross-sectional view conceptually showing the structure of the group III nitride crystal production apparatus 40 according to the present embodiment. In addition, about the component which has the effect similar to the preparation apparatus 10 which concerns on 1st Embodiment in the preparation apparatus 40, the code | symbol same as FIG. 1 is attached | subjected and the description is abbreviate | omitted.

  The manufacturing apparatus 40 according to the present embodiment includes a reaction tube 41 having a longitudinal direction in the vertical direction. Further, a susceptor 42 having a substantially horizontal mounting surface is provided inside the reaction tube 41. Further, a supply system 44 is provided above the reaction tube 41. That is, the manufacturing apparatus 40 has a vertical structure, unlike the horizontal structure manufacturing apparatus according to other embodiments.

  The supply system 44 has a supply pipe 44a. From the supply pipe 44a, the first gas g1 and the second gas g2 are supplied in a switchable manner by a predetermined switching means (not shown). Since the supply pipe 44a is provided such that the tip portion (supply port) reaches the vicinity of the susceptor 42, the first gas g1 or the second gas g2 flows to the vicinity of the susceptor 42 inside the reaction pipe 41. Each will be supplied. In the middle of the supply pipe 44a, a boat 15 for placing metal Al powder is provided.

  Further, in the supply system 44, the third gas g3 is supplied to the vicinity of the susceptor 42 through the outer peripheral portion of the supply pipe 44a (left and right portions of the supply pipe 44a in FIG. 4).

  Furthermore, in the outer peripheral portion of the reaction tube 41, as in the first embodiment, a portion including at least the boat 15 in the supply system 44 is provided in the reaction tube 11 in order to heat the reaction region of HCl and Al. A first heater 16 is provided for heating from the outside. Furthermore, a second heater 17 for heating the base substrate 13 placed on the susceptor 42 is provided in order to perform epitaxial growth on the base substrate 13.

  Also in the manufacturing apparatus 40 having such a configuration, similarly to the manufacturing apparatus 10, the control of the gas supply mode from the supply system 44 and the heating mode of the first heater 16 and the second heater 17 are controlled by a control unit (not shown). By appropriately performing the control, it is possible to produce a desired group III nitride crystal.

  In particular, the first gas g1 and the third gas g3 are supplied from the supply pipe 44a, and the second heater 17 heats the base substrate 13 without heating by the first heater 16, so that the MOCVD mode is achieved. It can be used in

  Further, the second gas g2 is supplied from the supply pipe 44a and the third gas g3 is supplied, and both the heating of the supply system 24 by the first heater 16 and the heating of the base substrate 13 by the second heater 17 are performed. Thus, it can be used in the HVPE mode.

  Therefore, similarly to the manufacturing apparatus 10 according to the first embodiment, the manufacturing apparatus 40 according to the present embodiment also manufactures a composite group III nitride having both the function of the MOCVD apparatus and the function of the HVPE apparatus. In the case of crystal growth on a single substrate, it is possible to switch between crystal growth in the MOCVD mode and crystal growth in the HVPE mode as appropriate.

  As a result, for example, as exemplified in the first embodiment, crystal growth in a mode in which AlN is grown in the HVPE mode on the AlN base film manufactured in the MOCVD mode is set with the same conditions. And can be done.

  As described above, also in the present embodiment, a composite group III nitride production apparatus having both the function of the MOCVD apparatus and the function of the HVPE apparatus is realized. According to such a manufacturing apparatus, when crystal growth on one substrate is performed by appropriately switching between a gas supply mode and a heating mode, crystal growth by MOCVD method and crystal growth by HVPE method are appropriately performed. Since it can be performed while switching, crystal growth with a higher degree of freedom is possible by taking advantage of the advantages of both methods.

It is a cross-sectional schematic diagram which shows notionally the structure of the preparation apparatus 10 which concerns on 1st Embodiment. It is a cross-sectional schematic diagram which shows notionally the structure of the preparation apparatus 20 which concerns on 2nd Embodiment. It is a cross-sectional schematic diagram which shows notionally the structure of the preparation apparatus 30 which concerns on 3rd Embodiment. It is a cross-sectional schematic diagram which shows notionally the structure of the preparation apparatus 40 which concerns on 4th Embodiment.

Explanation of symbols

10, 20, 30, 40 (Group III nitride crystal) production apparatus 11, 31, 41 Reaction tube 12, 42 Susceptor 13 Base substrate 14, 24, 34, 44 (Gas) supply system 14a-14d, 24a, 24b , 34a to 34c, 44a Gas supply pipe 15 Boat 16, 36 First heater 17 Second heater 18 Exhaust system 36a Upstream heater 36b Downstream heater

Claims (5)

An apparatus for producing a group III nitride crystal by performing a gas phase reaction between a group III element-containing gas and a nitrogen element-containing gas in a reaction tube,
A first group III element supply means for supplying an organic metal gas containing a group III element as the group III element-containing gas into the reaction tube;
Second group III element supply means for generating a halide gas by reacting a group III element metal and hydrogen halide, and supplying the halide gas as the group III element-containing gas into the reaction tube;
Nitrogen element supply means for supplying the nitrogen element-containing gas into the reaction tube;
With
When the group III nitride crystal is produced, the first and second group III element supply means are selectively used to supply the group III element-containing gas.
An apparatus for producing a group III nitride crystal characterized by the above. The manufacturing apparatus according to claim 1,
The gas supply ports of the first and second group III element supply means and the nitrogen element supply means are provided independently of each other at positions near the reaction region in the reaction tube.
An apparatus for producing a group III nitride crystal characterized by the above. The manufacturing apparatus according to claim 1 or 2,
Using ammonia gas as the nitrogen element-containing gas,
An apparatus for producing a group III nitride crystal characterized by the above. Using the manufacturing apparatus according to any one of claims 1 to 3,
A first forming step of forming a first group III nitride layer by performing a gas phase reaction between the group III element-containing gas supplied by the first group III element supply means and the nitrogen element-containing gas;
A second forming step of forming a second group III nitride layer by performing a gas phase reaction between the group III element-containing gas supplied by the second group III element supply means and the nitrogen element-containing gas;
Is performed a predetermined number of times, and a method for producing a laminated structure of group III nitride crystals. By using the manufacturing apparatus according to any one of claims 1 to 3,
A layer formed by reacting the group III element-containing gas supplied by the first group III element supply means and the nitrogen element-containing gas in a gas phase;
A layer formed by performing a gas phase reaction between the group III element-containing gas supplied by the second group III element supply means and the nitrogen element-containing gas;
A laminated structure of group III nitride crystals, characterized in that is formed continuously.

Images