JP6606562B2 - Method for producing gallium nitride single crystal and apparatus for producing group III element nitride single crystal - Google Patents

Description

The present invention relates to a method for producing a gallium nitride single crystal and an apparatus for producing a group III element nitride single crystal .

Group III element nitride semiconductors are used, for example, in the field of heterojunction high-speed electronic devices and optoelectronic devices (semiconductor lasers, light-emitting diodes, sensors, etc.). In particular, gallium nitride (GaN) has attracted attention as its material. Has been.
As a conventional method, in order to obtain a single crystal of gallium nitride, gallium and nitrogen gas are directly reacted (see J. Phys. Chem. Solids, 1995, Vol. 56, p. 639). .
However, this method requires ultrahigh temperature and high pressure of 1300 ° C. to 1600 ° C. and 8000 atm to 17000 atm (0.81 GPa to 1.72 GPa) in order to react gallium with nitrogen gas.
In order to solve this problem, a technique for growing a gallium nitride single crystal in sodium (Na) flux (hereinafter also referred to as “Na flux method”) has been developed (see, for example, US Pat. No. 5,868,837). According to the Na flux method, the heating temperature is greatly reduced to 600 ° C. to 800 ° C., and the pressure can be reduced to about 50 atm (about 5 MPa). However, in this Na flux method, the obtained single crystal may be blackened, and there is a problem in quality. In addition, this Na flux method cannot produce a single crystal of gallium nitride that is transparent, has a low dislocation density, a uniform thickness (crystal surface is almost horizontal), a high quality, and a large bulk gallium nitride. The yield of single crystals was also poor. That is, in the conventional Na flux method, the growth rate is extremely slow, and even the largest gallium nitride single crystal reported so far has a maximum diameter of about 1 cm. it dose not connect.
As another method, a method in which lithium nitride (Li ₃ N) and gallium are reacted to grow a gallium nitride single crystal has been reported (see Journal of Crystal Growth 247 (2003), pp.275-278). The size of the obtained crystal is about 1 mm to 4 mm.
The above problem is not limited to gallium nitride, but also applies to other Group III element nitride semiconductors.

  Japanese Patent No. 4030125 discloses a manufacturing method and a manufacturing apparatus that solve such problems. The isotropic production method and production apparatus can produce a large Group III element nitride single crystal that is transparent, has a low dislocation density, has a uniform thickness and is of high quality, and has a good bulk yield.

Japanese Patent No. 4030125

  The method for producing a group III element nitride single crystal described in Japanese Patent No. 4030125 is “at least one metal element selected from the group consisting of alkali metals and alkaline earth metals, gallium (Ga), and aluminum (Al). And heating a reaction vessel containing at least one group III element selected from the group consisting of indium (In) to form a flux of the metal element, introducing a nitrogen-containing gas into the reaction vessel, A method for producing a group III element nitride single crystal in which a group III element nitride is reacted with nitrogen in a flux to grow a group III element nitride single crystal, wherein the flux and A production method in which a group III element is mixed with stirring, and the single crystal is grown in that state. ].

  As the reaction vessel, carbon-based materials such as BN, AlN, alumina, SiC, graphite, and diamond-like carbon can be used, and among these, AlN, SiC, and diamond-like carbon are preferable. Further, as the reaction vessel, for example, a BN crucible, an AlN crucible, an alumina crucible, a SiC crucible, a graphite crucible, a crucible made of a carbon-based material such as diamond-like carbon, or the like can be used. Among these, an AlN crucible, a SiC crucible, and a diamond-like carbon crucible are preferable because they are difficult to dissolve in the flux. In addition, the crucible surface may be covered with these materials. (See paragraph No. 0029 of Japanese Patent No. 4030125).

However, since the flux is always in contact with the reaction vessel, there is a problem that the material of the reaction vessel starts to dissolve in the flux, which becomes an impurity of the group III element nitride single crystal. In particular, since it is necessary to keep the reaction vessel at a high temperature, the point that the material of the reaction vessel starts to melt has been a big problem. Further, when epitaxial growth is performed by immersing the substrate in the flux, there is a problem that polycrystals grow in a portion other than the substrate.
Furthermore, since the flux is always in the reaction vessel, as the group III element nitride single crystal grows, the component necessary for the growth of the group III element nitride single crystal in the flux, that is, the concentration of the group III element decreases. There was also a problem that the growth of the group III element nitride single crystal stopped.

The present invention was developed in view of the above problem, it is possible to achieve without mixing impurities in the gallium nitride single crystal, and and the growth rate does not drop method for producing a gallium nitride single crystal, the manufacturing process It aims at providing the manufacturing apparatus of a group III element nitride single crystal .

The manufacturing method of the one aspect | mode of the gallium nitride single crystal which concerns on this invention is from the group which consists of sodium (Na), lithium (Li), calcium (Ca), potassium (K), strontium (Sr), and magnesium (Mg). A mixed solution of at least one selected element and gallium (Ga) is heated to form a flux, a nitrogen-containing gas is introduced into the reaction chamber, and the internal pressure in the reaction chamber is set to 0.5 MPa to 5.MPa. The gallium nitride (GaN) single crystal is grown by reacting gallium (Ga) and nitrogen in the flux to 0 MPa, the atmospheric temperature in the reaction chamber is maintained at 700 ° C. to 900 ° C., and the base substrate is The gallium nitride (GaN) single crystal is grown by dropping the flux from above onto the base substrate while horizontally rotating.

The apparatus for producing a group III element nitride single crystal according to the present invention is selected from the group consisting of a reaction chamber in which a group III element nitride single crystal is produced on a base substrate and an alkali metal and an alkaline earth metal. The reaction for heating a mixed solution of at least one metal element and at least one group III element selected from the group consisting of gallium (Ga), aluminum (Al) and indium (In) to form a flux. A heating unit that heats the chamber, a nitrogen-containing gas introduction unit that introduces a nitrogen-containing gas to react the group III element in the flux with nitrogen in the reaction chamber, and the base substrate horizontally in the reaction chamber. A rotation drive unit that rotates, a dropping unit that drops the flux from above the base substrate, and the reaction chamber and is shaken off from the base substrate. And a collection unit for collecting the flux .

The manufacturing method of one embodiment of the gallium nitride single crystal according to the present invention grows the gallium nitride single crystal by dropping a flux on the base substrate while horizontally rotating the base substrate in the reaction chamber. A reaction vessel is not required. For this reason, the problem of mixing of impurities into the gallium nitride single crystal due to melting of the material of the reaction vessel does not occur.
Further, since the flux is dripped one after another, the gallium nitride single crystal grows as in the prior art, so the gallium concentration does not decrease. That is, since a fresh flux is always supplied, the problem that the growth of the gallium nitride single crystal stops does not occur.

As described above, the manufacturing apparatus of one embodiment of the group III element nitride single crystal according to the present invention does not require a conventional reaction vessel because the flux is dropped on the horizontally rotating base substrate. Therefore, there is no problem of mixing impurities into the group III element nitride single crystal due to melting of the reaction vessel material.
Further, since the flux is dripped one after another, the concentration of the group III element does not decrease as the group III element nitride single crystal grows as in the conventional case. That is, since a fresh flux is always supplied, there is no problem that the growth of the group III element nitride single crystal is lowered.
Furthermore, the apparatus for producing a group III element nitride single crystal according to the present invention has a recovery unit that recovers the flux shaken off from the base substrate, so that the flux can be reused after adjusting the concentration. There is a merit that it becomes possible.

It is a schematic explanatory drawing of the manufacturing apparatus of the manufacturing apparatus of the group III element nitride single crystal which concerns on embodiment of this invention. It is a schematic perspective view which shows the state which a flux spreads on the surface of a base substrate by the manufacturing apparatus of the group III element nitride single crystal which concerns on embodiment of this invention. It is a schematic explanatory drawing of the other manufacturing apparatus of the group III element nitride single crystal concerning embodiment of this invention. It is an electron micrograph of the section of the gallium nitride single crystal formed on the surface of the base substrate by the manufacturing method of the gallium nitride single crystal concerning the embodiment of the invention. It is an electron micrograph of the section of the gallium nitride single crystal formed on the surface of the base substrate by the manufacturing method of the gallium nitride single crystal concerning the embodiment of the invention. It is an electron micrograph of the section of the gallium nitride single crystal formed on the surface of the base substrate by the manufacturing method of the gallium nitride single crystal concerning the embodiment of the invention. It is the electron micrograph of the cross section of the base substrate which performed the control experiment of the manufacturing method of the gallium nitride single crystal which concerns on embodiment of this invention. It is the electron micrograph of the cross section of the base substrate which performed the control experiment of the manufacturing method of the gallium nitride single crystal which concerns on embodiment of this invention. It is the electron micrograph and schematic diagram of the surface of the base substrate which show the polycrystal considered to be the cause that the gallium nitride single crystal was not able to grow in the control experiment of the manufacturing method of the gallium nitride single crystal concerning an embodiment of the invention.

A method for producing a gallium nitride single crystal according to an embodiment of the present invention includes a group consisting of sodium (Na), lithium (Li), calcium (Ca), potassium (K), strontium (Sr), and magnesium (Mg). A mixed solution 910 of at least one element selected from gallium (Ga) is heated to form a flux 911, a nitrogen-containing gas is introduced into the reaction chamber 100, and the internal pressure in the reaction chamber 100 is increased. The gallium nitride (GaN) single crystal is grown by reacting gallium (Ga) and nitrogen in the flux 911 at 0.5 MPa to 5.0 MPa, and the ambient temperature in the reaction chamber 100 is set to 700 ° C. The flux 911 is dropped on the base substrate 800 from above while maintaining the temperature at 900 ° C. while the base substrate 800 is rotated horizontally. Gallium is adapted to grow a (GaN) single crystal.

A group III element nitride single crystal manufacturing apparatus that realizes such a manufacturing method includes a reaction chamber 100 in which a gallium nitride single crystal is manufactured on a base substrate 800, sodium (Na), lithium (Li), and calcium. In order to heat the mixed solution of at least one element selected from the group consisting of (Ca), potassium (K), strontium (Sr), and magnesium (Mg) and gallium (Ga) to form flux 911, A heating unit 400 that heats the reaction chamber 100; a nitrogen-containing gas introduction unit 500 that introduces a nitrogen-containing gas to react gallium (Ga) and nitrogen in the flux 911 in the reaction chamber 100; A rotation driving unit 200 that horizontally rotates the substrate 800 in the reaction chamber 100 and the flux 9 from above the base substrate 800. 11 and a collection unit 600 that is provided in the reaction chamber 100 and collects the flux 911 shaken off from the base substrate 800.

The reaction chamber 100 includes a cylindrical lower portion 110 and a lid portion 120 that is detachably attached to the upper end of the lower portion 110. The reaction chamber 100 is made of a nickel alloy.
In the center of the lid part 120, a nozzle 310 constituting a dropping part 300 described later is installed. Further, the lower end portion of the cylindrical lower portion 110 is curved inward and further curved upward. An annular corner is formed in the curved portion of the lower part 110. These corner portions serve as receiving groove portions 122 and constitute a part of a collecting portion 600 described later. The lowest part of the receiving groove part 122 is called the lowest part. Further, a through hole 121 is formed in the center of the curved portion of the lower portion 110 so as to penetrate the center in the vertical direction. A rotation shaft 210 of the rotation driving unit 200 described later is inserted into the through hole 121.

  The reaction chamber 100 is set inside the electric furnace 410 of the heating unit 400. The electric furnace 410 has a heater 420. A heater 420 heats the inside of the electric furnace 410 and maintains the atmospheric temperature inside the reaction chamber 100 in a range of 700 ° C. to 900 ° C.

The manufacturing apparatus includes a collecting unit 600 that collects the flux 911 shaken off from the horizontally rotating base substrate 800. The collection part 600 includes the receiving groove part 122, a collection tank 610 for storing what is received by the receiving groove part 122, and a collection pipe 620. The recovery pipe 620 opens to the lowest part of the receiving groove 122 and is connected to the recovery tank 610. The recovery unit 600 is installed inside the heat and pressure resistant chamber 700.

The manufacturing apparatus further includes a heat and pressure resistant chamber 700. In this group III element nitride single crystal manufacturing apparatus, an electric furnace 410 is housed in a heat and pressure resistant chamber 700, and a reaction chamber 100 is housed in the electric furnace 410. The internal pressure during the production of the gallium nitride single crystal in the heat and pressure resistant chamber 700 is set to 0.5 MPa to 5.0 MPa.

Although the reaction chamber 100 of the group III element nitride single crystal manufacturing apparatus described above is provided in the electric furnace 410 as the heating unit 400, the group III element nitride single crystal according to the embodiment of the present invention is provided. The crystal manufacturing apparatus is not limited to this.
For example, as shown in FIG. 3, a plurality of heaters 420 as the heating unit 400 may simply be installed around the reaction chamber 100.
In FIG. 3, the heater 420 is arranged on the upper side and the lower side of the reaction chamber 100, but in addition to this, the heater 420 may be installed on the side surface side of the reaction chamber 100, or on the upper side, the lower side and the reaction chamber 100. It is also possible to install only on either side.

The rotation drive unit 200 includes the rotation shaft 210, a turntable 220, and a motor 230 that rotates the rotation shaft 210. The turntable 220 is provided at the tip of the rotating shaft 210 and is disposed in the reaction chamber 100. The turntable 220 is horizontally rotated around the rotation shaft 210 by a motor 230. The turntable 220 is driven at, for example, 5 to 300 revolutions / minute. The turntable 220 is preferably made of alumina (Al ₂ O ₃ ) or nickel alloy, but is not limited thereto.
The turntable 220 is circular, and convex veins 221 are formed on the outer peripheral edge. By fitting the base substrate 800 inside the convex vein 221, the base substrate 800 is prevented from being detached while the turntable 220 is rotating. Further, the center of the turntable 220 is positioned directly below the nozzle 310.
Note that a speed reduction mechanism is provided between the motor 230 and the rotary shaft 210, but the illustration thereof is omitted in the drawings.

The dripping unit 300 includes the nozzle 310, a supply valve 320 that controls the supply of the mixed solution 910 to the nozzle 310, a storage tank 330 that stores the mixed solution 910, a pipe 340, a heater 350, have. The heater 350 is disposed at least around the storage tank 330 and heats the mixed solution 910 in the storage tank 330.
The nozzle 310 is installed at the center of the lid 120 of the reaction chamber 100. Therefore, the nozzle 310 is positioned directly above the center of the turntable 220. The nozzle 310 is made of a nickel alloy and is heated to 500 ° C. to 600 ° C. so that the material of the nozzle 310 does not dissolve in the mixed solution 910.
Further, the supply valve 320 is opened, for example, so that the dropping amount of the flux 911 dropped from the nozzle 310 is 1 g to 10 g / min.
Note that a heater 350 may be disposed not only in the storage tank 330, the supply valve 320, and the nozzle 310, but also around the pipe 340 connecting them so as to keep the temperature of the mixed solution 910 constant.
The dripping unit 300 is installed inside the heat and pressure resistant chamber 700.

  The mixed solution 910 includes at least one metal element selected from the group consisting of alkali metals and alkaline earth metals, and at least one selected from the group consisting of gallium (Ga), aluminum (Al), and indium (In). It is a mixture of two Group III elements. Note that gallium (Ga) is suitable as the group III element for the mixed solution 910 that is most suitable for producing heterojunction high-speed electronic devices and optoelectronic devices (semiconductor lasers, light-emitting diodes, sensors, and the like).

The alkali metal is lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr). The alkaline earth metal is calcium (Ca), Magnesium (Mg), strontium (Sr), barium (Ba) and radium (Ra).
These metals may be used alone or in combination of two or more. Among these, preferred are Li, Na, Ca, K, Sr, and Mg, more preferred are Li, Na, and Ca, and more preferred is a mixed flux of Na and Ca and Na and Li. And mixed flux. In these cases, the ratio (mol%) of calcium (Ca) or lithium (Li) to the total of sodium (Na) and calcium (Ca) or lithium (Li) is, for example, in the range of 0.1 mol% to 99 mol%. Preferably, it is the range of 0.1 mol%-50 mol%, More preferably, it is the range of 2.5 mol%-30 mol%. The ratio (mol%) of sodium (Na) to the total of gallium (Ga) and sodium (Na) is, for example, in the range of 0.1 mol% to 99.9 mol%, preferably 30 mol% to 99 mol. %, And more preferably in the range of 60 mol% to 95 mol%. The molar ratio of gallium: sodium: lithium or calcium is particularly preferably 3.7: 9.75: 0.25.

  Further, as described above, the group III element is preferably gallium (Ga). In this case, the group III element nitride single crystal is a gallium nitride (GaN) single crystal.

  As the base substrate 800, a sapphire substrate having a GaN thin film previously formed on the surface is suitable. The base substrate 800 is of a size that fits within the convex veins 221 of the turntable 220, for example, 6 inches (15.24 cm) in diameter.

The nitrogen-containing gas introduction unit 500 includes a gas tank 510 that can store a nitrogen-containing gas, and a pipe 520 that connects the gas tank 510 to the heat and pressure resistant chamber 700. As the nitrogen-containing gas, at least one selected from the group consisting of nitrogen (N ₂ ) gas, ammonia (NH ₃ ) gas, and mixed gas is used. The mixed gas is a mixed gas of nitrogen (N ₂ ) gas and ammonia (NH ₃ ).
Further, the nitrogen-containing gas in the gas tank 510 may be diluted with an inert gas such as argon (Ar).

Production of a gallium nitride single crystal by the apparatus for producing a group III element nitride single crystal thus configured is performed as follows.
First, the lid 120 of the reaction chamber 100 is removed outside the heat and pressure resistant chamber 700, and the base substrate 800 is set on the turntable 220.
The reaction chamber 100 with the lid 120 closed is installed in a heat-resistant pressure-resistant chamber 700, and a nitrogen-containing gas is introduced into the heat-resistant pressure-resistant chamber 700 by a nitrogen-containing gas introduction unit 500, so that the internal pressure is 0.5 MPa to 5.0 MPa. Increase the pressure. At the same time, the atmospheric temperature inside the heat and pressure resistant chamber 700 is raised to 700 ° C. to 900 ° C. by the heating unit 400.
Further, the temperature of the mixed solution 910 stored in the storage tank 330 of the dropping unit 300 is raised to 550 ° C. to 650 ° C.

  The turntable 220 is rotated at 5 to 300 revolutions / minute while the internal pressure and atmospheric temperature of the heat and pressure resistant chamber 700 and the temperature of the mixed solution 910 are constant.

The supply valve 320 of the dropping unit 300 is opened, and the mixed solution 910 is supplied from the storage tank 330 to the nozzle 310. The mixed solution 910 supplied to the nozzle 310 is heated in the reaction chamber 100 to become a flux 911, and this flux 911 is dropped from the nozzle 310 at a rate of 1 g to 10 g / min.
The flux 911 dropped from the nozzle 310 spreads in the form of a film on the surface of the base substrate 800 as indicated by an arrow A in FIG. The metal element ( sodium (Na) and lithium (Li), calcium (Ca), potassium (K), strontium (Sr), and magnesium (Mg)) contained in the film-like flux 911 is selected. it is the at least one element) and gallium nitride single crystal is a group III element nitride single crystal by a nitrogen contained in the nitrogen-containing gas to react to grow on the surface of the base substrate 800.

Since the base substrate 800 rotates at 5 to 300 revolutions / minute, the flux 911 dropped onto the base substrate 800 spreads from the center of the base substrate 800 toward the outer periphery by centrifugal force and adheres to the surface without unevenness. Since new flux 911 is successively supplied to the base substrate 800, a gallium nitride single crystal, which is a group III element nitride single crystal, sequentially grows on the surface of the base substrate 800.
Since the base substrate 800 is rotating, excess flux 911 scatters from the outer periphery of the base substrate 800 and is collected in the receiving groove portion 122 of the curved collection portion 600 of the lower portion 110 of the reaction chamber 100, via the collection pipe 620. It is recovered in the recovery tank 610.

Since the flux 911 supplied to the base substrate 800 is always new, the concentration is always constant, and the concentration decreases as the gallium nitride single crystal, which is a group III element nitride single crystal , grows. The conventional problem of stopping is not present in the group III element nitride single crystal manufacturing apparatus according to the embodiment of the present invention.
Further, since the excess flux 911 is recovered by the recovery unit 600, it can be reused after adjusting the concentration.

Experiments 1 to 3 were performed under the following conditions.

Experiment 1
Ga: Flux = 30: 70 Unit:% by weight
Flux weight Ga: 3.19 (g)
Na: 2.37 (g)
Li: 0.08 (g)
Flux mixing ratio
Na: 90 (%)
Li: 10 (%)
Flux dripping amount: 5.64 g / min Substrate used: HVPE GaN epitaxial wafer manufactured by Paudec Co., Ltd. Growth pressure: 0.98 Mpa
Growth time: 60 minutes Growth temperature: 800 ° C
Substrate rotation speed: 300 rotations / minute Nitrogen-containing gas: Nitrogen gas

Experiment 2
Ga: Flux = 30: 70 Unit:% by weight
Flux weight Ga: 3.17 (g)
Na: 2.31 (g)
Li: 0.13 (g)
Flux mixing ratio
Na: 85 (%)
Li: 15 (%)
Flux dripping amount: 5.61 g / min Substrate used: HVPE GaN epitaxial wafer manufactured by Paudec Co., Ltd. Growth pressure: 0.98 Mpa
Growth time: 60 minutes Growth temperature: 800 ° C
Substrate rotation speed: 300 rotations / minute Nitrogen-containing gas: Nitrogen gas

Experiment 3
Ga: Flux = 30: 70 Unit:% by weight
Flux weight Ga: 3.05 (g)
Na: 2.17 (g)
Li: 0.177 (g)
Flux mixing ratio
Na: 80 (%)
Li: 20 (%)
Flux dripping amount: 5.40 g / min Substrate used: HVPE GaN epitaxial wafer manufactured by Paudec Co., Ltd. Growth pressure: 0.98 Mpa
Growth time: 60 minutes Growth temperature: 800 ° C
Plate rotation speed: 300 rev / min Nitrogen-containing gas: Nitrogen gas

In the above experiments 1 to 3, a gallium nitride single crystal (GaN single crystal) that is a group III element nitride single crystal was successfully grown on the surface of the base substrate 800.
4 is an experiment 1, FIG. 5 is an experiment 2, and FIG. 6 is an electron micrograph of a cross section of a uniform GaN single crystal obtained in experiment 3.
In addition, the black part below each figure is a cross section of the base substrate 800, and the gray part above it is a cross section of the GaN single crystal.
Further, the magnification of each figure is 15000 times in FIG. 4, 5000 times in FIG. 5, and 10,000 times in FIG. The reason why the magnification is different in each figure is to avoid a problem that the GaN single crystal becomes unclear when the same magnification is used because the thickness of the GaN single crystal grown on the surface of the base substrate 800 is different.

Moreover, the control experiment A and the control experiment B were performed as a control experiment of experiment 1 and experiment 2.
In the control experiment A and the control experiment B, the base substrate 800 was rotated at 300 revolutions / minute in Experiments 1 and 2, whereas the base substrate 800 was not rotated at all. Conditions other than the rotation of the base substrate 800 are in accordance with Experiment 1 and Experiment 2, respectively.

FIG. 7 is an electron micrograph of a cross section of the base substrate 800 of the control experiment A and FIG. 8 is a control experiment B.
7 and 8, even if the flux 911 is dropped on the stationary base substrate 800 that is not rotating , a gallium nitride single crystal that is a group III element nitride single crystal is formed on the surface of the base substrate 800. It can be seen that (GaN single crystal) does not grow at all.
An electron micrograph (magnification 1000 times) and a schematic diagram of this GaN polycrystal are shown in FIG.
The reason why a gallium nitride single crystal (GaN single crystal) does not grow at all on the surface of the base substrate 800 is that a GaN polycrystal like a lid is formed on the surface of the base substrate 800, and as a result, nitrogen is formed on the base substrate 800. It is estimated that it does not reach.
That is, by rotating the base substrate 800 horizontally, the flux 911 dropped on the base substrate 800 spreads into a thin and uniform film, and a GaN polycrystal like a lid is not generated. As a result, it is considered that a uniform GaN single crystal grows on the surface of the base substrate 800. 7 and 9 are electron micrographs with the GaN polycrystal shown in FIG. 9 removed.

In addition, a control experiment was performed in which the conditions other than the rotation speed of the base substrate 800 were made equal and the rotation speed was 2000 rotations / minute. In this control experiment, a GaN single crystal could be grown on the surface of the base substrate 800. There wasn't .
When the base substrate 800 is rotated at a high speed of 2000 revolutions / minute, it is considered that the flux 911 is scattered from the surface of the base substrate 800 faster than the growth of the GaN single crystal.

DESCRIPTION OF SYMBOLS 100 Reaction chamber 200 Rotation drive part 300 Dripping part 400 Heating part 500 Nitrogen-containing gas introduction part 800 Base substrate 910 Mixed solution 911 Flux

Claims (5)

A mixture of sodium (Na), at least one element selected from the group consisting of lithium (Li), calcium (Ca), potassium (K), strontium (Sr), and magnesium (Mg), and gallium (Ga) The solution is heated to form a flux,
A nitrogen-containing gas is introduced into the reaction chamber, the internal pressure in the reaction chamber is set to 0.5 MPa to 5.0 MPa, and gallium (Ga) and nitrogen in the flux are reacted to form a gallium nitride (GaN) single crystal. Growing,
Gallium nitride that grows the gallium nitride (GaN) single crystal by maintaining the atmospheric temperature in the reaction chamber at 700 ° C. to 900 ° C. and horizontally rotating the base substrate while dropping the flux on the base substrate from above. A method for producing a single crystal . The method for producing a gallium nitride single crystal according to claim 1, wherein the mixed solution is heated to 550 ° C. to 650 ° C. to form the flux . The nitrogen-containing gas is at least one selected from the group consisting of nitrogen (N ₂ ) gas, ammonia (NH ₃ ) gas, and mixed gas, and the mixed gas includes nitrogen (N ₂ ) gas and ammonia (NH _3). 3) The method for producing a gallium nitride single crystal according to claim 1 or 2, which is a mixed gas with a gas. The method for producing a gallium nitride single crystal according to any one of claims 1 to 3, wherein the flux is dropped at 1 g / min to 10 g / min . An apparatus for producing a group III element nitride single crystal,
A reaction chamber in which a group III element nitride single crystal is produced on a base substrate;
At least one metal element selected from the group consisting of alkali metals and alkaline earth metals and at least one group III element selected from the group consisting of gallium (Ga), aluminum (Al) and indium (In) A heating unit for heating the reaction chamber to heat the mixed solution into a flux;
A nitrogen-containing gas introduction part for introducing a nitrogen-containing gas in order to react the group III element in the flux and nitrogen in the reaction chamber;
A rotation drive unit for horizontally rotating the base substrate in the reaction chamber;
A dropping unit for dropping the flux from above the base substrate;
An apparatus for producing a group III element nitride single crystal, comprising: a recovery unit that is provided in the reaction chamber and recovers the flux shaken off from the base substrate .