JP5524758B2 - Crystal growth equipment - Google Patents

Description

  The present invention relates to a crystal growth apparatus in which a crystal substance is vapor-phase grown on a substrate by reacting the substrate disposed in a reaction zone while heating the substrate.

Aluminum-based group III nitride has a large band gap energy. For example, the band gap energy of aluminum nitride is about 6.2 eV, and the band gap energy of gallium nitride is about 3.4 eV. Aluminum gallium nitride is a mixed crystal of aluminum nitride and gallium nitride, and takes a band gap energy between the band gap energies of aluminum nitride and gallium nitride according to the ratio of both components.
Therefore, by using an aluminum-based group III nitride, it becomes possible to emit light in the short wavelength in the ultraviolet region, which is impossible with other semiconductors, and for ultraviolet light emitting diodes for white light sources, ultraviolet light emitting diodes for sterilization, and high density optical disc memories Light emitting light sources such as lasers that can be used for reading and writing and lasers for communication can be manufactured.

  In general, an attempt has been made to produce a light emitting light source function as described above by laminating a thin film of several microns or less on a conventional substrate. It is formed by crystal growth methods such as the well-known molecular beam epitaxy (MBE) method, metalorganic vapor phase epitaxy (MOVPE) method, etc., and is an optimal stack for the purpose of expressing the light emitting function. Much research has already been done on the formation of structures.

In the following Non-Patent Document 1, a reactor having a wall formed of quartz glass, a group III halide gas introduction means containing aluminum halide into the reactor, a nitrogen source gas introduction means, and a substrate support There is disclosed a hydride vapor phase epitaxy crystal growth apparatus comprising: In addition, a heating support with a built-in heating resistor is used as the support of the crystal growth apparatus, and graphite is used as the heating resistor of the heating support. Such a heating resistor is used by being coated with pyrolytic boron nitride to protect the heating resistor. Moreover, it heats also by the external heating means installed in the outer side of a reactor, and a heating support stand periphery part is heated.
In the following non-patent document 2 shown in FIG. 6, in the vertical reactor 51, gas introducing means 52 is provided on the upper side, and chlorine gas is reacted with the aluminum wire 57 and supplied to the reactor 55. A support base 54 made of graphite of the substrate 53 is provided in the lower deposition area 58, and a high-frequency coil 56 is disposed on the outer periphery of the reactor 55 where the support base 54 is located. High frequency heating is possible.

Journal of Crystal Growth Volume 300, Issue 1, 1 March 2007, Pages 42-44 A. Claudel, et al., Journal of Crystal Growth Volume 311, Issue 13, 15 June 2009, Pages 3371-3379

However, it is desirable to raise the temperature from 1700 ° C. to 1800 ° C. in order to obtain high-quality crystals of the aluminum-based group III nitride.
In Non-Patent Document 1, pyrolytic boron nitride is used for coating for protecting the heat generating resistor. When the temperature of the heat generating resistor is 1500 ° C. or higher, decomposition of the pyrolytic boron nitride cannot be ignored, and heat is generated. The resistor graphite is exposed to the corrosive gas present in the reaction system. Since the graphite and the corrosive gas react vigorously and damage the graphite severely, the temperature cannot be increased beyond the decomposition of the pyrolytic boron nitride, and there is a limit to reacting the raw material at a high temperature.
In the technique of Non-Patent Document 2, since the high-frequency coil 56 is used as a heating means, the support 54 can be heated to a high temperature, but graphite is used for the support 54 and the graphite is an impurity at a high temperature. Is generated and decomposed, causing impurity contamination of the aluminum-based group III nitride growth layer.
Furthermore, since the reactor 55 of Non-Patent Document 2 has a vertical system and is vertically long, gas convection occurs in the vertical direction, and the source gas cannot be efficiently supplied onto the substrate by convection. Thus, in order to obtain high-quality crystals, it has been a problem to reduce gas convection.
The present invention has been made in view of such circumstances. In order to obtain a high-quality aluminum-based group III nitride crystal, the reaction temperature can be maintained at a high temperature, and gas convection in the reactor can be suppressed as much as possible. An object is to provide a crystal growth apparatus.

In order to achieve the above object, the crystal growth apparatus of the present invention reacts a group III halide gas containing aluminum halide and a nitrogen source gas on the substrate while heating the substrate disposed in the reaction zone. In the crystal growth apparatus for vapor-phase-growing aluminum-based group III nitride on the substrate, the vertical tube portion extending in the vertical direction and the horizontal tube portion extending in the left-right direction from the upper end portion of the vertical tube portion are configured. A T-shaped reactor, a tungsten heating support that holds the substrate in a region where the upper end of the vertical tube portion faces the horizontal tube portion, and an upper periphery of the vertical tube portion A high-frequency coil for inductively heating the heating support, a first gas supply pipe that is introduced into the horizontal tube portion and supplies the group III halide onto the substrate, and is introduced into the horizontal tube portion and the nitrogen Source gas to the substrate And it includes a second gas supply pipe for supplying, and an exhaust port for formed on the end side of the transverse pipe portion discharge the gas in the reactor.
In the crystal growth apparatus, a bottom surface of the heating support base is connected to a support shaft that extends downward from the vertical tube portion, and the support shaft is connected to a rotation shaft of a drive motor disposed below the vertical tube portion. It is preferable to rotate the support base around the support shaft.
The crystal growth apparatus includes a tube that partitions an inner peripheral surface of the vertical tube portion and the support shaft, and a first gas inlet port in an annular space formed between the inner peripheral surface and the tube And a second gas introduction port is provided in a central space between the tube and the support shaft, and the gas introduced from these gas introduction ports is discharged from the exhaust port through the horizontal tube portion. It is preferable.
In the crystal growth apparatus, the lower end portion of the support shaft is preferably formed of a quartz material.
In the crystal growth apparatus, it is preferable that a partition plate for vertically partitioning the horizontal tube portion is disposed in the horizontal tube portion positioned above the substrate.

The crystal growth apparatus of the present invention is provided with a T-shaped reactor composed of a vertical tube portion extending in the vertical direction and a horizontal tube portion extending in the left-right direction from the upper end portion of the vertical tube portion. A first gas supply pipe for supplying the Group III halide onto the substrate; and a second gas supply pipe for supplying the nitrogen source gas to the substrate after being introduced into the horizontal pipe portion. . Gas is easy to convect in the vertical direction due to temperature differences, etc., but by using the horizontal tube part, by preventing convection in the vertical direction of the gas, the supply of the raw material onto the substrate is suitably performed, and a more suitable reaction Can give environment.
The crystal growth apparatus can reduce the incorporation of impurities by using a tungsten heating support that holds the substrate in a region where the upper end of the vertical tube portion faces the horizontal tube portion.
The crystal growth apparatus can be reacted in a high temperature environment by using a high frequency coil for inductively heating the heating support.
In the crystal growth apparatus, since the support base is rotated around the support shaft by the drive motor, uniform crystals can be generated by rotating the substrate .

It is sectional drawing seen from the front side of the principal part of the crystal growth apparatus by embodiment of this invention. It is an expanded sectional view of the gas introduction part in the crystal growth apparatus of FIG. It is sectional drawing of the gas introduction part in the AA direction shown in FIG. It is an expanded sectional view of the reaction part in the crystal growth apparatus of FIG. It is an expanded sectional view of the gas exhaust part in the crystal growth apparatus of FIG. It is a schematic sectional drawing of the crystal growth apparatus of a nonpatent literature.

Hereinafter, a crystal growth apparatus according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a crystal growth apparatus according to the present invention. The crystal growth apparatus 1 mainly includes a reaction tube 2, a reaction unit 3, a source gas introduction unit 4, a rotation drive unit 5, and a gas exhaust unit 6.
The reaction tube 2 is entirely T-shaped when viewed from the front, and is a horizontal horizontal tube 7 having a circular cross section extending in the horizontal direction, and a vertical tube 8 extending in the vertical direction and having a circular cross section. It is constituted by. The horizontal tube 7 includes an intermediate tube 11 disposed inside the horizontal tube 7, an inner tube 12 disposed inside the intermediate tube 11, and an exhaust tube 13 disposed on the right end side. It is installed. Each of the intermediate tube 11 and the inner tube 12 is hollow, and the diameter becomes smaller in the order of the horizontal tube 7, the intermediate tube 11, and the inner tube 12, and between the horizontal tube 7 and the intermediate tube 11, the intermediate tube 11 and the inner tube 12. A slight gap is formed between the two.

The intermediate tube 11 is disposed without being extended to the end wall (left end wall in FIG. 1) 7a and the exhaust pipe 13 of the horizontal tube 7 on the side of the raw material gas introduction unit 4 and spaced apart from them. It extends across 3 from side to side. In the reaction unit 3, the middle tube 11 and the horizontal tube 7 form an opening having the same shape as the upper end opening of the vertical tube 8, so that the insides of the vertical tube 8 and the horizontal tube 7 communicate with each other. In order to prevent the inner side of the horizontal tube 7 from becoming dirty, the intermediate tube 11 is disposed at least across the reaction portion and extends to the vicinity of the end wall 7a from the viewpoint of preventing contamination. preferable.
The inner pipe 12 extends to a substantially intermediate position on the side from the one end side of the horizontal pipe 7 on the gas exhaust part 6 side to the reaction part 3. These horizontal tube 7, vertical tube 8, middle tube 11 and inner tube 12 are made of quartz in this embodiment.

Next, the source gas introduction unit 4 will be described.
With reference to FIGS. 1 to 3, the source gas introduction unit 4 is provided with four gas introduction units on the end wall 7 a of the horizontal tube 7.
A barrier gas introduction pipe 14 is connected as a first system, and a halide gas introduction pipe (hereinafter simply referred to as a halide gas pipe) 15 which is a first gas supply pipe of the present invention is connected as a second system. Further, a carrier gas introduction pipe 16 is connected as a third system, and a nitrogen source gas pipe 17 which is a second gas supply pipe of the present invention is connected as a fourth system.

The barrier gas introduction pipe 14 is connected to a gas supply source (not shown) of N ₂ gas that is a barrier gas. The barrier gas introduction pipe 14 penetrates the end wall 7a and is reduced in diameter in the middle, so that the tip thereof reaches the reaction section 3.
The halide gas pipe 15 is connected to a gas supply source (not shown) of a halide gas that is a group III source of the aluminum-based group III nitride. The halide gas pipe 15 is disposed inside the barrier gas introduction pipe 14, is formed continuously through the end wall 7 a together with the barrier gas introduction pipe 14 to the center of the horizontal pipe 7, and the tip thereof reaches the reaction section 3. ing. The shape of the halide gas pipe 15 in the reaction tube 2 is substantially straight and extends in the horizontal direction from the proximal end side to the distal end portion thereof, and the distal end portion extends to the reaction portion 3.

The carrier gas introduction pipe 16 is connected to a gas supply source (not shown) of H ₂ gas or N ₂ gas which is a carrier gas. The carrier gas introduction pipe 16 is provided with a gas supply port 16a for introducing the carrier gas into the reaction tube (horizontal tube) 2 in the end wall 7a, and the carrier gas is directly introduced into the reaction tube 2 from the gas supply port 16a. To do. Accordingly, the carrier gas flows from the gas supply port 16a to the reaction unit 3 and further to the exhaust pipe 13 side.
The nitrogen source gas pipe 17 is connected to a gas supply source (not shown) of ammonia gas as a nitrogen source of the aluminum-based group III nitride. The nitrogen source gas pipe 17 is disposed below the carrier gas introduction pipe 16, is continuously formed through the end wall 7 a to the inside of the reaction tube, and the tip thereof reaches the reaction section 3. The shape of the nitrogen source gas pipe 17 in the reaction tube 2 is such that a stepped portion 17a extending from the horizontal direction to the lower side is formed at the intermediate portion, and an inclined portion that is inclined downward is formed at the tip portion, and the tip is the reaction portion. 3 is directed to the center of a substrate described later (see reference numeral 21 in FIG. 4). The nitrogen source gas pipe 17 is arranged at a position higher than the intermediate position height in the vertical direction on the end wall 7a of the horizontal pipe 7, and is arranged to pass through a position lower than the intermediate position at the stepped portion 17a. .

  Partition plates 19 that partition the horizontal tube 7 up and down are disposed in the horizontal direction at an intermediate position in the vertical direction of the horizontal tube 7 and an intermediate position in the horizontal direction of the horizontal tube 7. The nitrogen source gas pipe 17 is disposed at a position where the front end side is lower than the partition plate 19 by the stepped portion 17 a and along the bottom surface of the partition plate 19. Therefore, the nitrogen source gas pipe 17, the barrier gas introduction pipe 14, and the halide gas pipe 15 are disposed below the partition plate 19. In addition, although these gas pipes 14-17 and the partition plate 19 provide the clamp material etc. in the horizontal pipe 7 and / or the middle pipe | tube 11 etc., they are abbreviate | omitted about support structure.

Next, the reaction unit 3 and the rotation drive unit 5 will be described.
With reference to FIGS. 1 and 4, the reaction unit 3 is provided at the intersection of the upper portion of the vertical tube 8 and the horizontal tube 7, and a heating support base 22 for placing the substrate 21 and a support shaft for supporting the heating support base 22. 23 and a high-frequency coil 24. The heating support base 22 is made of tungsten, and the upper surface thereof is disposed at the same height as the lower surface (outer peripheral surface) of the horizontal tube 7 or the intermediate tube 11. 22a is formed, and the substrate 21 is disposed in the recess 22a. The height of the substrate 21 (the mounting surface of the substrate 21 of the heating support 22 + the thickness of the substrate 21) is preferably in the range of −30 mm to +30 mm with respect to the upper end portion of the vertical tube 8.
The shape of the heating support 22 is not particularly limited as long as the surface on which the substrate 21 is installed is flat in order to transmit heat uniformly to the substrate 21. Although FIG. 1 shows the columnar heating support 22, its shape can be changed according to the temperature at which the substrate 21 is heated. For example, in the heating support table 22 that is induction-heated by the high frequency coil, when the temperature of the central portion of the upper surface on which the substrate 21 is installed becomes too high, the thickness of the lower center of the heating support table 22 is reduced accordingly. You can also.
A high frequency coil 24 is disposed below the horizontal tube 7 and on the upper end side of the vertical tube 8 so as to surround the heating support base 22 and the vertical tube 8. The high frequency coil 24 is connected to a high frequency power source (not shown).

  The heating support base 22 is supported by a support shaft 23, and the heating support base 22 rotates as the support shaft 23 rotates about the axis. The support shaft 23 is arranged in the vertical direction at the center of the vertical tube 8, and the lower portion of the support shaft 23 is connected to a cylindrical quartz column 26. The quartz column 26 is accommodated in a cup 27, and the periphery of the quartz column 26 is covered with the cup 27 except for its upper end side. The lower end portion of the quartz column 26 is connected to a drive shaft 28, and the drive shaft 28 passes through the bottom wall 8 a of the vertical tube 8 and is connected to a drive motor 29 disposed below the bottom wall 8 a. Therefore, the support shaft 23, the quartz column 26 and the drive shaft 28 are aligned on the same line, and the rotational force of the drive motor 29 is transmitted to the drive shaft 28, the quartz column 26 and the support shaft 23, so 22 can be rotated.

Between the inner peripheral surface of the vertical tube 8, the support shaft 23, and the cup 27 (and the quartz column 26), a tube 31 that partitions the vertical tube 8 in the radial direction is provided. 32b is formed and the outer flow path 32a is formed outside. The lower end side of the tube 31 is connected to the bottom wall 8a of the vertical tube 8, the upper end side extends to the upper end of the vertical tube 8, and the upper end portion forms a flange portion 31a protruding radially outward. The flange portion 31a and the vertical tube 8 is formed between the heating support base 22 and the inner peripheral surface of the tube 31, and the horizontal tube 7 and the vertical tube are interposed through these clearances. 8 communicates.
A first pipe 34 for introducing hydrogen gas or nitrogen gas in the vertical direction is connected to the end of the bottom wall 8a of the vertical pipe 8. A storage pipe 33 through which the drive shaft 28 penetrates is provided at the lower part of the bottom wall 8a of the vertical pipe 8, and a second pipe 35 for introducing hydrogen gas or nitrogen gas in the horizontal direction in the intermediate part of the storage pipe 33. Is connected. The first pipe 34 communicates with the outer flow path 32a of the vertical pipe 8, and the other second pipe 35 communicates with the inner flow path 32b.

Next, the gas exhaust unit 6 will be described.
1 and 5, the horizontal pipe 7 is connected to the exhaust pipe 13 at the right end, the right end side of the exhaust pipe 13 is closed (not shown), and the discharge pipe 13a is provided downward at the bottom. ing. A gas injection pipe 36 is provided slightly on the side of the reaction section 3 of the horizontal pipe 7. The gas injection pipe 36 is connected to a nitrogen gas supply source (not shown), and nitrogen gas can be introduced between the inner pipe 12 and the horizontal pipe 7 from the gas injection pipe 36.
A flange 12a that extends radially outward is formed at the right end of the inner pipe 12, and is closed so that no gas flows to the exhaust pipe 13 side. Flows from the gap between the inner tube 12 and the inner tube 12 to the left, and a part flows into the gap between the inner peripheral surface of the horizontal tube 7 and the outer peripheral surface of the middle tube 11.

Next, the operation of the crystal growth apparatus according to the embodiment of the present invention will be described.
First, it is preferable to circulate a carrier gas from which an impurity gas component such as oxygen, water vapor, carbon monoxide or carbon dioxide has been removed in advance using a purifier before the operation of the crystal growth apparatus.
The substrate 21 is installed in the recess 22 a of the heating support 22. As the substrate, a crystal substrate such as sapphire, silicon, silicon carbide, zinc oxide, gallium nitride, or aluminum nitride is used. Furthermore, a template substrate in which a thin aluminum nitride crystal layer is laminated on an initial substrate such as sapphire can also be used.

With reference to FIGS. 1 and 2, in the horizontal tube 7 of the reaction tube 2, an aluminum halide gas, for example, aluminum trichloride gas, is supplied from the halide gas tube 15 onto the substrate 21 together with the barrier gas in the barrier gas introduction tube 14. To do. For the aluminum trichloride gas, a group III halide gas may be obtained by separately providing a reactor and a heating device upstream of the halide gas pipe 15 to react aluminum and hydrogen halide.
Further, as the group III halide gas, not only aluminum trichloride alone but also other gases such as gallium halides such as gallium trichloride and the like depending on the mixed crystal composition of the target aluminum group III nitride. A halide gas such as indium halide such as indium chloride may be mixed as appropriate and supplied to the halide gas pipe 15. Especially, since the apparatus of this invention can be used conveniently at high temperature of 1700-1800 degreeC, it is preferable to manufacture aluminum group III nitride using chloride aluminum gas.
As the nitrogen source gas of the nitrogen source gas pipe 17, a reactive gas containing nitrogen is adopted, but ammonia gas is preferable in terms of cost and ease of handling.

In the present embodiment, as shown in FIG. 2, a barrier gas is jetted between aluminum trichloride gas and ammonia gas, and between the aluminum trichloride gas and ammonia gas at the tip of the halide gas pipe. A barrier gas is interposed. The barrier gas is interposed in order to prevent the aluminum trichloride gas and the ammonia gas from reacting to become an intermediate product before reaching the base substrate.
The carrier gas from the carrier gas introduction pipe 16 functions to flow the gas in one direction in the reactor. As the kind of carrier gas, hydrogen, nitrogen, helium, argon simple gas, or a mixed gas thereof can be used.

As shown in FIG. 4, the substrate 21 is preferably installed in a range of 30 mm to 80 mm from the nozzle tips of the normal gas pipes 14, 15, and 17.
In the bottom wall 8a of the vertical pipe 8, nitrogen gas (or hydrogen gas) flows from the first pipe 34 to the outer flow path 32a and from the second pipe 35 to the inner flow path 32b. The flow of nitrogen gas into the outer flow path 32a serves to prevent the raw material gas from entering the vertical pipe 8 and to flow the raw material gas into the exhaust port 13b on the exhaust pipe 13 side. The reason why the nitrogen gas is flowed into the inner flow path 32b is to prevent the raw material gas from touching the support shaft 23 and the like, that is, to prevent corrosion of the support shaft 23 and the like.

By driving the drive motor 29, the heating support base 22 rotates with the drive shaft 28, the quartz column 26, and the support shaft 23 interposed. A voltage is applied to the high frequency coil 24 from a high frequency power source, the heating support 22 is heated by high frequency induction heating, and the substrate 21 is also heated. By generating heat by this induction heating, the substrate 21 placed on the heating support 22 can be heated to a temperature of about 1700 ° C. to 1800 ° C.
The support shaft 23 is connected to the heating support base 22 that is heated to a high temperature and attempts to conduct heat to the drive shaft 28 and the drive motor 29 side at a high temperature, but between the support shaft 23 and the drive shaft 28, Since the quartz pillar 26 is provided, it is possible to prevent damage to members on the drive unit side due to heat. Note that the gas in the pipes 34 and 35 has an effect of cooling the support shaft 23 in addition to preventing intrusion of the raw material gas and the like.

Under such an environment, the source gas is supplied from the tip portions of the nitrogen source gas pipe 17 and the halide gas pipe 15, and crystals grow on the substrate 21. Since the nitrogen gas source tube 17 is inclined downward so that the ammonia gas reaches the surface of the substrate 21, the nitrogen source gas tube 17 can be supplied efficiently.
The horizontal tube 7 can prevent gas convection in the vertical direction due to gas temperature difference during crystal growth. In particular, since the ceiling height is limited due to the presence of the partition plate 19 in the reaction unit 3, it is possible to prevent convection due to gas rise and efficiently feed the raw material gas into the reaction zone.

As shown in FIG. 5, from the gas injection pipe 36, nitrogen gas is allowed to flow through the gap between the horizontal pipe 7 and the inner pipe 12, and the inner peripheral surface of the horizontal pipe 7 is contaminated by ammonium halide generated by the reaction. Can be prevented. Specifically, a part of the nitrogen gas flows through the gap S1 between the middle tube 11 and the inner tube 12 from the gap between the horizontal tube 7 and the inner tube 12, enters the inner tube 12 through the gap end Sa, and is discharged. The remaining nitrogen gas escapes from the gap S2 between the horizontal tube 7 and the middle tube 11 from the gap end Sb (see FIG. 4) in the reaction unit 3, passes through the middle tube 11 and the inner tube 12, and is discharged from the discharge port 13b. Is done. Similarly, a part of the carrier gas supplied from the carrier gas introduction pipe 16 passes through the gap end Sc (see FIG. 2) between the horizontal pipe 7 and the intermediate pipe 11 via the gap end Sb (see FIG. 2) in the reaction section. 4), through the middle tube 11 and the inner tube 12, and discharged from the discharge port 13b. Accordingly, since the reaction gas does not enter the gap, the inner peripheral surface of the horizontal tube 7 can be maintained in a clean state.
As a result, the inside of the reactor can be kept clean for a long time by exchanging only the inner tube 12. The gas introduced into the reaction tube 2 is supplied from the left end wall 7 a side of the horizontal tube 7, passes through the reaction unit 3, and is exhausted from the discharge port 13 b of the gas exhaust unit 6. The introduced gas is discharged from the discharge port 13 b of the gas exhaust unit 6 through the reaction unit 3.

Under such an environment, the reaction can be performed in a high temperature environment of 1700 to 1800 ° C. in the reaction part. As a matter of course, the apparatus of the present invention is not limited to the case where the temperature of the reaction section is 1700 ° C. or higher, and can be sufficiently used even when the temperature is lower than 1700 ° C.
The substrate temperature is maintained at a desired temperature by controlling the high-frequency power source of the high-frequency coil 24. In the case where carbon is used for the heating support table, there is a problem of generation of impurities at a high temperature. However, for the heating support table 22, tungsten is used as a material to reduce the generation of impurities and to have high purity. Can be produced. Thus, by reacting at a high temperature, a high-quality aluminum-based group III nitride can be vapor-grown on the substrate 21. Since the crystal is grown while rotating the substrate 21, a uniform crystal can be obtained on the substrate 21.

After a certain period of time has elapsed and crystals have grown on the substrate 21, the supply of halide gas is stopped, the growth is terminated, and the temperature of the heating device is lowered. When hydrogen is used as the carrier gas, it is desirable that the nitrogen source gas flows through the reactor until the temperature of the substrate decreases in order to prevent re-decomposition of the group III nitride grown on the substrate.
By the above procedure, an aluminum-based group III nitride can be obtained. The crystallinity of the resulting aluminum-based III-nitride can be made from low crystallinity close to amorphous to single crystal or polycrystal with good crystallinity by changing parameters such as temperature and raw material gas supply amount. Is possible. Among them, the apparatus of the present invention can easily make the temperature of the reaction part (substrate 21) in a high temperature environment of 1700 to 1800 ° C. Therefore, among aluminum group III nitrides, aluminum contained in group III atoms Can be suitably used in the case of producing an aluminum-based group III nitride single crystal having a ratio of 50% or more. Among these, it can be particularly suitably used when producing an aluminum nitride single crystal.

The present invention has been described in detail based on the embodiments with reference to the accompanying drawings. However, the present invention is not limited to the above-described embodiments, and other modifications can be made without departing from the scope of the present invention. Or it can be changed.
The material of the group III halide gas pipe (nozzle) 15 is preferably quartz glass. However, when a group III halide crystal is used as a group III halide gas supply source, a corrosion resistant metal such as stainless steel, inconel, or hastelloy is used. It is also possible to use the gas pipe 15.

DESCRIPTION OF SYMBOLS 1 Crystal growth apparatus 2 Reaction tube 3 Reaction part 4 Raw material gas introduction part 5 Rotation drive part 6 Gas exhaust part 7 Horizontal pipe 8 Vertical pipe 13 Exhaust pipe 13b Exhaust port 14 Barrier gas introduction pipe 15 Halide gas pipe (1st gas supply) tube)
16 Carrier gas introduction pipe 17 Nitrogen source gas pipe (second gas supply pipe)
19 Partition plate 21 Substrate 22 Heating support base 23 Support shaft 24 High frequency coil 26 Quartz pillar 27 Cup 29 Drive motor
31 Tube 32a outer channel (annular space)
32b in the flow path (center space)

Claims (5)

By reacting a group III halide gas containing aluminum halide and a nitrogen source gas on the substrate while heating the substrate disposed in the reaction zone, the aluminum-based group III nitride is vaporized on the substrate. In a crystal growth apparatus for phase growth,
A T-shaped reactor composed of a vertical pipe portion extending in the vertical direction and a horizontal pipe portion extending in the left-right direction from the upper end portion of the vertical pipe portion;
A heating support made of tungsten for holding the substrate in a region located at the upper end opening of the vertical tube portion and facing the horizontal tube portion;
A high-frequency coil disposed around the upper side of the vertical pipe portion and induction-heating the heating support;
A first gas supply pipe that is introduced into the horizontal pipe section and supplies the group III halide onto the substrate;
A second gas supply pipe introduced into the horizontal pipe section and supplying the nitrogen source gas onto the substrate;
A crystal growth apparatus comprising an exhaust port formed on an end side of the horizontal tube portion and exhausting the gas in the reactor.   A bottom surface of the heating support base is connected to a support shaft extending downward from the vertical tube portion, and the support shaft is connected to a rotation shaft of driving means disposed at a lower portion of the vertical tube portion, and the support shaft is centered on the support shaft. The crystal growth apparatus according to claim 1, wherein the support base is rotated. A tube for partitioning between the inner peripheral surface of the vertical tube portion and the support shaft is provided, a first gas inlet is formed in an annular space formed between the inner peripheral surface and the tube, and the tube A second gas introduction port is provided in a central space between the gas supply port and the support shaft, and gas introduced from these gas introduction ports is discharged from the exhaust port through the horizontal pipe portion. The crystal growth apparatus described in 1.   The crystal growth apparatus according to claim 2 or 3, wherein a quartz material is interposed between the support shaft and the driving means.   The crystal growth apparatus according to any one of claims 1 to 4, wherein a partition plate for vertically partitioning the horizontal tube portion is disposed in the horizontal tube portion positioned above the substrate.

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