JP5582028B2 - Crystal growth equipment - Google Patents

Description

  The present invention relates to a crystal growth apparatus.

  Gallium nitride (GaN) is expected as a next-generation semiconductor material. One of the methods for producing GaN is a crystal growth method (so-called so-called so-called crystal growth method in which a seed substrate is immersed in a Na / Ga melt at 800 ° C. to 900 ° C. in a high-pressure nitrogen atmosphere of several MPa and a GaN crystal is grown on the seed substrate. Flux method) is known.

GaN crystal growth apparatus used for manufacturing a GaN crystal, the melt of the nitrogen gas under heated and pressurized atmosphere _{(N 2),} gallium (Ga) of the melt becomes (liquid Ga) and flux sodium U beam (Na) And a reaction vessel for growing a GaN crystal on a seed substrate immersed in the melt by reacting with the melt comprising, and a nitrogen gas supply pipe for supplying nitrogen gas into the reaction vessel (For example, refer to Patent Document 1).

  When a GaN crystal is manufactured using a GaN crystal growth apparatus, GaN crystal is grown by reacting gallium and nitrogen gas in a state where nitrogen gas is supplied from a nitrogen gas supply pipe into the reaction vessel. The liquid Ga in the reaction vessel is consumed by reaction with nitrogen gas.

  By the way, in order to grow GaN greatly, it is necessary to perform crystal growth of GaN for a long time. For example, it is important to maintain the ratio of liquid Ga to liquid Na during the GaN crystal growth period. For this reason, there is a need for a technique for adjusting the liquid Ga consumed along with the growth of the GaN crystal to an amount corresponding to the consumption rate of the liquid Ga accompanying the growth of the GaN crystal and continuously supplying the liquid Ga into the reaction vessel. . Therefore, a configuration has been proposed in which a Ga supply pipe for sequentially supplying Ga into the reaction vessel is provided.

JP 2008-266099 A

  However, when the Ga supply pipe is provided, the nitrogen gas in the reaction vessel and the sodium gas floating in the nitrogen atmosphere (sodium gas evaporated from the melt) may flow into the Ga supply pipe. When nitrogen gas and sodium gas flow into the Ga supply pipe, Ga remaining in the Ga supply pipe reacts with nitrogen through the sodium gas. Thereby, GaN (miscellaneous crystals) is formed in the Ga supply pipe, and the Ga supply pipe may be blocked.

  The present invention has been made in view of the above-described problems, and suppresses the formation of GaN (miscellaneous crystals) in the Ga supply pipe and can suppress the blockage of the Ga supply pipe. The purpose is to provide.

  In order to solve the above-described problems, the present invention provides a reaction between a first raw material and a melt composed of a second raw material and a flux in a heating and pressurizing atmosphere, on a seed substrate immersed in the melt. A reaction vessel for growing crystals, a first supply pipe for supplying the first raw material to the reaction vessel, a first supply source for supplying the first raw material to the first supply pipe, and the second raw material for the first raw material A second supply pipe for supplying the reaction container; a second supply source for supplying the second raw material to the second supply pipe; a third supply pipe for supplying an inert gas to the reaction container; and the third supply. A third supply source for supplying the inert gas to the pipe, and the third supply source prevents the flux gas evaporated from the melt from flowing into the second supply pipe. And supplying the inert gas to the reaction vessel via To adopt a crystal growth apparatus to be.

  By adopting such a configuration, in the present invention, the inert gas is supplied to the third supply pipe by the third supply source so that the flux gas evaporated from the melt does not flow into the second supply pipe. . For this reason, unlike the patent document 1, the flux gas evaporated from the melt does not flow into the second supply pipe. Therefore, it is possible to provide a crystal growth apparatus capable of suppressing the formation of miscellaneous crystals in the second supply pipe and suppressing the blockage of the second supply pipe.

In the present invention, a configuration is adopted in which the first supply pipe and the third supply pipe are made of the same pipe, and the first supply source and the third supply source are made of the same supply source. .

  In the present invention, a configuration is adopted in which nitrogen gas is used as the first raw material and the inert gas, gallium is used as the second raw material, and sodium is used as the flux.

  In the present invention, the second supply pipe is inserted into the upper part of the reaction vessel, and is a vertical supply passage perpendicular to the reaction vessel, and an inclined supply passage having a downward inclination toward the reaction vessel. And the structure which has at least one of these is employ | adopted.

  In the present invention, the second supply pipe adopts a configuration in which a tip end portion has a tapered shape.

In the present invention, the second supply pipe and the third supply pipe form a single pipe, and the second supply source supplies the second raw material to the reaction vessel via the second supply pipe. After the supply, a configuration is adopted in which the third supply source supplies the inert gas to the reaction vessel via the third supply pipe.

Further, in the present invention, the second supply pipe and the third supply pipe form a double pipe , the second supply pipe is arranged on the inside, and the third supply pipe is arranged on the outside. And when the second supply source supplies the second raw material to the reaction vessel via the second supply pipe, the third supply source supplies the inert gas via the third supply pipe. The structure of supplying to the reaction vessel is adopted.

  In the present invention, the third supply pipe employs a configuration in which a tip end portion has a tapered shape.

According to the present invention, the inert gas is supplied to the third supply pipe so that the flux gas evaporated from the melt does not flow into the second supply pipe by the third supply source. For this reason, unlike the patent document 1, the flux gas evaporated from the melt does not flow into the second supply pipe.
Therefore, according to the present invention, a crystal growth apparatus that can suppress the formation of miscellaneous crystals in the second supply pipe and suppress the blockage of the second supply pipe is obtained.

It is a schematic diagram which shows schematic structure of the crystal growth apparatus in 1st Embodiment of this invention. It is a schematic diagram which shows schematic structure of the obstruction | occlusion releasing apparatus in 1st Embodiment of this invention. It is a schematic diagram which shows the 2nd supply piping and 3rd supply piping in 2nd Embodiment of this invention. It is a schematic diagram which shows the 2nd supply piping and 3rd supply piping in 3rd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. This embodiment shows one aspect of the present invention, and does not limit the present invention, and can be arbitrarily changed within the scope of the technical idea of the present invention. Moreover, in the following drawings, in order to make each structure easy to understand, an actual structure and a scale, a number, and the like in each structure are different.

(First embodiment)
FIG. 1 is a schematic diagram showing a schematic configuration of a crystal growth apparatus in a first embodiment of the present invention. In the following description, a gallium nitride manufacturing apparatus will be described as an example of the crystal growth apparatus of this embodiment.

  As shown in FIG. 1, a gallium nitride production apparatus 1 is for producing a GaN crystal on a seed substrate 11 by a flux method. The gallium nitride manufacturing apparatus 1 includes a reaction vessel 10 that holds a seed substrate 11 and a mixed melt 12, a heat insulating vessel 20 that surrounds the outside of the reaction vessel 10, a pressure vessel 30 that surrounds the outside of the heat insulating vessel 20, and a mixed melt. 12, and a pressure adjusting device (not shown) that adjusts the internal pressure of the pressure vessel 30. In addition, the side part of the reaction container 10, the heat insulation container 20, and the pressure vessel 30 is formed in the concentric cylindrical shape. The reaction vessel 10, the heat insulation vessel 20, and the pressure vessel 30 are set so that their concentric cylindrical central axes are in the vertical direction.

  The gallium nitride manufacturing apparatus 1 supplies a first supply pipe for supplying the first raw material to the reaction container 10, a first supply source for supplying the first raw material to the first supply pipe, and a second raw material for the reaction container 10. A second supply pipe, a second supply source for supplying the second raw material to the second supply pipe, a third supply pipe for supplying the inert gas to the reaction vessel 10, and an inert gas for supplying the third supply pipe And a third supply source. Furthermore, the gallium nitride manufacturing apparatus 1 includes a clogging release device 100 that releases clogging of the second supply pipe. The “inert gas” refers to a gas that is inert to grow crystals on the seed substrate 11 by the reaction between the first material and the second material.

In the present embodiment, the first supply pipe and the third supply pipe are made of the same pipe, and the first supply source and the third supply source are made of the same supply source. Thereby, compared with the case where the first supply pipe and the third supply pipe are made of different pipes, and the first supply source and the third supply source are made of different supply sources, the apparatus can be simplified and miniaturized. Can be planned.

In the present embodiment, nitrogen gas (N ₂ ) is used as the first raw material and inert gas, gallium (Ga) is used as the second raw material, and sodium (Na) is used as the flux. In the following description, a nitrogen gas supply pipe (N ₂ supply pipe) 61 as a first supply pipe and a third supply pipe, a nitrogen gas supply source (N ₂ cylinder) 60 as a first supply source and a third supply source, a second A liquid gallium supply pipe (Ga supply pipe) 51 is exemplified as the supply pipe, and a liquid gallium supply source (Ga tank) 50 is exemplified as the second supply source.

  The reaction vessel 10 has a mixed melt 12 made of Na / Ga inside. The reaction vessel 10 is made of, for example, a ceramic crucible. Thereby, it is possible to prevent foreign substances such as impurities from entering the reaction vessel 10. The reaction vessel 10 has a configuration in which a seed substrate 11 is placed on the bottom and immersed in the mixed melt 12 inside. The internal pressure of the reaction vessel 10 is set to several MPa to 10 MPa. The temperature of the mixed melt 12 is set to 800 ° C to 900 ° C.

  As the heat insulating material of the heat insulating container 20, for example, a fiber heat insulating material such as glass wool is used. A heater 21 that heats the reaction vessel 10 is provided inside the heat insulation vessel 20 so as to surround the side and bottom of the reaction vessel 10.

  The pressure vessel 30 is composed of a vacuum vessel whose shape is set in a substantially cylindrical shape so that it can withstand the pressure even when the pressure state changes. The pressure vessel 30 is connected to an evacuation means 80 for evacuating the internal air. The vacuum exhaust means 80 includes an exhaust pipe 81, an on-off valve 82, and a pressure adjustment valve 83. The on-off valve 82 opens and closes an exhaust gas passage that passes between the pressure vessel 30 and the pressure regulating valve 83. The pressure adjustment valve 83 adjusts or reduces the discharge pressure of the exhaust gas from the pressure vessel 30 to a constant state.

  The stirrer 40 includes a drive shaft 41 inserted through the reaction vessel 10, a stirrer 42 fixed to one end of the drive shaft 41, and a drive unit 43 that rotates the drive shaft 41. One end of the drive shaft 41 is inserted into the reaction vessel 10 and reaches the mixed melt 12. The drive shaft 41 includes a stirring body 42 at the tip of one end. The stirring body 42 has a substantially disk shape. The diameter of the stirring body 42 is larger than the diameter of the drive shaft 41. The drive unit 43 is fixedly provided outside the pressure vessel 30. The drive unit 43 includes a drive source such as a motor or a solenoid, for example. The stirrer 42 fixed to the drive shaft 41 is rotated by the drive unit 43 so that the mixed melt 12 inside the reaction vessel 10 is stirred.

  Inside the Ga tank 50, liquid Ga is accommodated. A heater 56 is provided outside the Ga tank 50 to surround the Ga tank 50 and to heat the Ga tank 50. The heating temperature of the heater 56 is set to about 50 ° C. to 70 ° C., for example.

  The Ga supply pipe 51 is provided between the Ga tank 50 and the reaction vessel 10. Specifically, one end of the Ga supply pipe 51 is connected to the lower part of the Ga tank 50, and the other end is inserted into the upper part of the reaction vessel 10. The Ga supply pipe 51 has a vertical supply path 51Ra perpendicular to the reaction container 10 and an inclined supply path 51Rb having a downward inclination toward the reaction container 10. Thereby, liquid gallium can be flowed into the reaction vessel 10 without being retained in the Ga supply pipe 51.

  The Ga supply pipe 51 has a tapered shape with a tapered tip that protrudes into the reaction vessel 10. Thereby, the sodium gas evaporated from the mixed melt 12 toward the Ga supply pipe 51 flows outward along the tapered shape of the tip of the Ga supply pipe 51. For this reason, it is possible to suppress sodium gas (Na gas) evaporated from the mixed melt 12 from flowing into the Ga supply pipe 51. Note that the Ga supply pipe 51 is formed of, for example, a ceramic material from the viewpoint of preventing impurity contamination.

  The Ga supply pipe 51 is provided with a plurality of on-off valves 52 a, 52 b, 52 c, a pump 53, a pressure regulating valve 54, and a check valve 55 in the path from the Ga tank 50 to the reaction vessel 10.

  The on-off valve 52 a opens and closes a liquid Ga passage that passes between the Ga tank 50 and the pump 53. The pump 53 increases or decreases the pressure of the liquid Ga supplied from the Ga tank 50. The on-off valve 52 b opens and closes the liquid Ga passage that passes between the pump 53 and the pressure adjustment valve 54. The pressure adjustment valve 54 adjusts or reduces the discharge pressure of the liquid Ga from the pump 53 to a constant state. The check valve 55 always keeps the flow of the liquid Ga constant and prevents the liquid Ga from flowing back.

  With such a configuration, the liquid Ga consumed along with the growth of the GaN crystal inside the reaction vessel 10 is adjusted so as to have an amount corresponding to the consumption rate of the liquid Ga accompanying the growth of the GaN crystal. To supply.

  A heater 57 is provided outside the Ga supply pipe 51. The heater 57 heats the Ga supply pipe 51 (the passage between the Ga tank 50 and the pressure vessel 30), the plurality of on-off valves 52a, 52b, and 52c, the pump 53, the pressure regulating valve 54, and the check valve 55. The heating temperature of the heater 57 is set to about 50 ° C. to 70 ° C., for example.

Nitrogen gas (N ₂ ) is accommodated in the N ₂ cylinder 60. In the present embodiment, three N ₂ cylinders 60 are provided. Note that the number of N ₂ cylinders 60 is not limited to three, and may be changed as needed, such as one or two, four or more.

The N ₂ supply pipe 61 is provided between the N ₂ cylinder 60 and the check valve 55. Specifically, one end of the N ₂ supply pipe 61 is connected to the upper part of the N ₂ cylinder 60, and the other end is connected to the inclined supply path 51 Rb of the Ga supply pipe 51. Note that the N ₂ supply pipe 61 is made of, for example, a ceramic material from the viewpoint of preventing impurity contamination.

The N ₂ supply pipe 61 is provided with a plurality of on-off valves 62 a and 62 b and pressure adjusting valves 63 and 64 in the path from the N ₂ cylinder 60 to the check valve 55.

The on-off valve 62 a opens and closes the N ₂ passage that passes between the N ₂ cylinder 60 and the pressure regulating valve 63. The pressure regulating valve 63 increases or decreases the pressure of N ₂ supplied from the N ₂ cylinder 60. The pressure adjusting valve 64 adjusts or reduces the discharge pressure of N ₂ from the pressure adjusting valve 63 to a constant state. For example, the pressure regulating valve 64 sets the pressure of N ₂ to several MPa to 10 MPa, and sets the flow rate of N ₂ to several tens sccm to several hundred sccm. The on-off valve 62 b opens and closes the N ₂ passage that passes between the pressure adjustment valve 64 and the check valve 55. Incidentally, the check valve 55 will always maintain a constant flow of _{N 2,} to prevent backflow of _{N 2.}

With such a configuration, N ₂ consumed along with the growth of the GaN crystal inside the reaction vessel 10 is adjusted so as to be an amount corresponding to the consumption rate of N ₂ accompanying the growth of the GaN crystal. To supply.

N ₂ gas cylinder 60 supplies the _{N 2} in the reaction vessel 10 Na gas evaporated from the mixed melt 12 via the _{N 2} supply pipe 61 so as not to flow into the Ga supply pipe 51. _{N 2} supplied by N ₂ gas cylinder 60 is supplied to the Ga supply pipe 51 via the _{N 2} supply pipe 61. N ₂ supplied to the Ga supply pipe 51 flows into the reaction vessel 10 via the inclined supply path 51Rb and the vertical supply path 51Ra.

In the present embodiment, the Ga supply pipe 51 and the N ₂ supply pipe 61 form a single pipe. In other words, in the vertical supply path 51Ra (and a part of the inclined supply path 51Rb) of the Ga supply pipe 51, the liquid Ga supply path and the N ₂ supply path are the same. After Ga tank 50 was fed a liquid Ga to the reaction vessel 10 via a Ga supply pipe 51 supplies the _{N 2} in the reaction vessel 10 _{N 2} gas cylinder 60 through the _{N 2} supply pipe 61.

  Thereby, it is possible to suppress the Na gas evaporated from the mixed melt 12 from flowing into the vertical supply path 51Ra of the Ga supply pipe 51.

  The blockage releasing device 100 is connected to the vertical supply path 51Ra of the Ga supply pipe 51 via the blockage releasing pipe 71. An opening / closing valve 72 is provided in the closing release pipe 71. The on-off valve 72 opens and closes the passage of the insertion portion 101 (see FIG. 2) that passes between the closure release device 100 and the vertical supply path 51Ra of the Ga supply pipe 51.

  FIG. 2 is a schematic diagram showing a schematic configuration of the occlusion releasing device according to the first embodiment of the present invention. The clog release device 100 is used during maintenance such as when a GaN crystal is not manufactured in the gallium nitride manufacturing device 1. The clogging release device 100 releases the clogging of the Ga supply pipe 51 when GaN miscellaneous crystals are formed in the Ga supply pipe 51.

  As shown in FIG. 2, the clogging release device 100 includes an insertion part 101 that is inserted into the Ga supply pipe 51, a guide part 110 that guides the insertion part 101, a flange part 111 that supports the guide part 110, and a support part. 120, a first drive unit 130 that moves the insertion unit 101 along the guide unit 110, and a second drive unit 140 that rotates the insertion unit 101.

  The insertion portion 101 has a sharp end at one end (−Z-axis direction side). Thereby, when the GaN miscellaneous crystal is formed in the Ga supply pipe 51, the blockage of the Ga supply pipe 51 can be reliably released. The insertion portion 101 includes a first magnetic body such as metal at the other end (+ Z-axis direction side).

  The guide part 110 is provided on the flange part 111. The guide part 110 has a hollow cylindrical shape extending in one direction (Z-axis direction). The inner diameter of the guide part 110 is set larger than the outer diameter of the other end part of the insertion part 101.

  The flange portion 111 has a disk shape. The diameter of the flange portion 111 is set larger than the outer diameter of the guide portion 110. The flange portion 111 functions as a connection portion that connects the closure release device 100 and the closure release pipe 71 (see FIG. 1).

The support part 120 includes a second magnetic body 121 that supports the other end of the insertion part 101 with a magnetic force, and a base part 122 that supports the second drive part 140. As the second magnetic body 121, for example, a magnet can be used. Thereby, the attractive force acts between the second magnetic body 121 and the first magnetic body. An opening 123 having a circular shape in plan view is formed in the base portion 122 at a position overlapping the guide portion 110. The diameter of the opening 123 is set larger than the outer diameter of the guide part 110.

  The first drive unit 130 includes a first motor 131, a small-diameter circular gear (pinion) 132, and a toothed bar (rack) 133. The first drive unit 130 has a so-called rack and pinion mechanism. The rotational force generated by the first motor 131 is converted into a linear motion by the rack and pinion mechanism. The first drive unit 130 moves the insertion unit 101 up and down along the guide unit 110.

  The second drive unit 140 includes a second motor 141 and a transmission unit 142 that transmits the rotational force generated by the second motor 141 to the second magnetic body 121. The second drive unit 140 rotates the insertion unit 101 around the Z axis.

  With such a configuration, GaN miscellaneous crystals formed in the Ga supply pipe 51 are removed. The GaN miscellaneous crystals (shaving powder) removed by the clogging release device 100 are dropped into the reaction vessel 10 or dropped into another vessel. The reaction vessel 10 is washed so that no shavings remain during maintenance.

Therefore, in this embodiment, N ₂ is supplied to the N ₂ supply pipe 61 so that the Na gas evaporated from the mixed melt 12 does not flow into the Ga supply pipe 51 by the N ₂ cylinder 60. For this reason, Na gas evaporated from the melt as in Patent Document 1 does not flow into the Ga supply pipe. Therefore, it is possible to provide the gallium nitride manufacturing apparatus 1 capable of suppressing the formation of miscellaneous crystals of GaN in the Ga supply pipe 51 and suppressing the blockage of the Ga supply pipe 51.

In the present embodiment, the first supply pipe and the third supply pipe are the same pipe, and the first supply source and the third supply source are the same supply source. Thereby, compared with the case where the first supply pipe and the third supply pipe are made of different pipes, and the first supply source and the third supply source are made of different supply sources, the apparatus can be simplified and miniaturized. Can be planned.

  In this embodiment, nitrogen gas is used as the first raw material and inert gas, gallium is used as the second raw material, and sodium is used as the flux. Thereby, compared to the case where the first raw material and the inert gas are made of different gases, the raw material to be used can be reduced, and the GaN crystal can be manufactured at a low cost.

  Further, in the present embodiment, the other end of the Ga supply pipe 51 is inserted into the upper part of the reaction vessel 10 and is perpendicular to the reaction vessel 10 and is inclined downward toward the reaction vessel 10. And an inclined supply path 51Rb. Thereby, liquid gallium can be flowed into the reaction vessel 10 without being retained in the Ga supply pipe 51.

  Moreover, in this embodiment, the front-end | tip part of Ga supply piping 51 becomes a taper taper shape. Thereby, the sodium gas evaporated from the mixed melt 12 toward the Ga supply pipe 51 flows outward along the tapered shape of the tip of the Ga supply pipe 51. For this reason, it is possible to suppress the Na gas evaporated from the mixed melt 12 from flowing into the Ga supply pipe 51.

In the present embodiment, the Ga supply pipe 51 and the N ₂ supply pipe 61 form a single pipe, and after the Ga tank 50 supplies liquid Ga to the reaction vessel 10 through the Ga supply pipe 51, N ₂ The cylinder 60 supplies N ₂ to the reaction vessel 10 through the N ₂ supply pipe 61. Thereby, it is possible to suppress the Na gas evaporated from the mixed melt 12 from flowing into the vertical supply path 51Ra of the Ga supply pipe 51.

In addition, although this embodiment illustrated and demonstrated the case where nitrogen gas was used as an inert gas, it is not restricted to this. For example, argon gas, helium gas, or hydrogen gas can be used as the inert gas. In this case, the gallium nitride manufacturing apparatus is configured such that the first supply pipe and the third supply pipe are different from each other, and the first supply source and the third supply source are different from each other.

  Moreover, although this embodiment illustrated and demonstrated the case where gallium was used as a 2nd raw material, it is not restricted to this. For example, a group 13 metal such as aluminum, indium, or thallium can be used.

  Moreover, although this embodiment illustrated and demonstrated the case where sodium was used as a flux, it is not restricted to this. For example, alkali metals such as lithium and potassium, alkaline earth metals such as magnesium and calcium, and mixtures thereof can be used as the flux.

  In the present embodiment, the configuration in which the Ga supply pipe 51 includes the vertical supply path 51Ra through which the Ga supply pipe 51 is inserted into the upper portion of the reaction vessel 10 and the inclined supply path 51Rb is described as an example, but the present invention is not limited thereto. For example, the Ga supply pipe may be configured to have a vertical supply path that passes through the top of the reaction vessel, or may have a configuration that includes an inclined supply path that passes through the top of the reaction vessel. That is, the Ga supply pipe may be inserted into the upper part of the reaction vessel and have at least one of a vertical supply path and an inclined supply path.

(Second Embodiment)
Next, the configuration of the gallium nitride manufacturing apparatus 170 according to the second embodiment of the present invention will be described with reference to FIG. Drawing 3 is a mimetic diagram showing the 2nd supply piping and the 3rd supply piping in a 2nd embodiment of the present invention. In FIG. 3, the components (see FIG. 1) other than the second supply pipe and the third supply pipe projecting into the reaction vessel are the same as those of the above-described gallium nitride production apparatus 1. The illustration is omitted. As shown in FIG. 3, the gallium nitride manufacturing apparatus 170 of this embodiment is a gallium nitride described in the first embodiment in that the second supply pipe and the third supply pipe form a double pipe. Different from the manufacturing apparatus 1. In the following description, a liquid gallium supply pipe (Ga supply pipe) 171 is exemplified as the _second supply pipe, and a nitrogen gas supply pipe (N ₂ supply pipe) 172 is exemplified as the third supply pipe.

In the gallium nitride manufacturing apparatus 170 of this embodiment, a Ga supply pipe 171 and an N ₂ supply pipe 172 form a double pipe having a coaxial central axis. Ga supply pipe 171 is arranged on the inner side, and N ₂ supply pipe 172 is arranged on the outer side. The front end (−Z direction side) of the Ga supply pipe 171 is disposed on the inner side (+ Z direction side) than the front end (−Z direction side) of the N ₂ supply pipe 172. When the Ga tank 50 (see FIG. 1) supplies the liquid Ga to the reaction vessel 10 (see FIG. 1) via the Ga supply pipe 171, the N ₂ cylinder 60 (see FIG. 1) passes through the N ₂ supply pipe 172. N ₂ is supplied to the reaction vessel 10.

Therefore, in this embodiment, even when the liquid Ga is being supplied to the reaction vessel 10 through the Ga supply pipe 171, N ₂ can be continuously supplied to the reaction vessel 10 through the N ₂ supply pipe 172. Therefore, after the Ga tank 50 was fed a liquid Ga to the reaction vessel 10 via a Ga supply pipe 171, as compared with the case _{where N 2} gas cylinder 60 supplies the _{N 2} in the reaction vessel 10 through the _{N 2} supply pipe 172 Thus, it is possible to suppress the Na gas evaporated from the mixed melt 12 from flowing into the Ga supply pipe 171. Therefore, it is possible to provide the gallium nitride manufacturing apparatus 170 capable of suppressing the formation of miscellaneous crystals of GaN in the Ga supply pipe 171 and suppressing the blockage of the Ga supply pipe 171.

(Third embodiment)
Next, the configuration of the gallium nitride manufacturing apparatus 270 according to the third embodiment of the present invention will be described with reference to FIG. FIG. 4 is a schematic diagram showing the second supply pipe and the third supply pipe in the third embodiment of the present invention corresponding to FIG. In FIG. 4, the components (see FIG. 1) other than the second supply pipe and the third supply pipe projecting into the reaction vessel are the same as those in the gallium nitride production apparatus 1 described above, and for convenience, The illustration is omitted. As shown in FIG. 4, the gallium nitride manufacturing apparatus 270 of the present embodiment is the gallium nitride manufacturing apparatus described in the second embodiment described above in that the tip of the third supply pipe has a tapered shape. Different from 170 . In the following description, a liquid gallium supply pipe (Ga supply pipe) 271 is exemplified as the _second supply pipe, and a nitrogen gas supply pipe (N ₂ supply pipe) 272 is exemplified as the third supply pipe.

In the gallium nitride manufacturing apparatus 270 of this embodiment, a Ga supply pipe 271 and an N ₂ supply pipe 272 form a double pipe whose central axis is coaxial. The Ga supply pipe 271 is arranged on the inner side, and the N ₂ supply pipe 272 is arranged on the outer side. The front end (−Z direction side) of the Ga supply pipe 271 is disposed on the inner side (+ Z direction side) than the front end (−Z direction side) of the N ₂ supply pipe 272. When the Ga tank 50 (see FIG. 1) supplies the liquid Ga to the reaction vessel 10 (see FIG. 1) via the Ga supply pipe 171, the N ₂ cylinder 60 (see FIG. 1) passes through the N ₂ supply pipe 172. N ₂ is supplied to the reaction vessel 10.

The N ₂ supply pipe 272 has a tapered shape with a tapered tip. Specifically, a flow path conversion unit 273 having an inclined surface 273 a that is inclined with respect to the longitudinal direction of the Ga supply pipe 271 is provided inside the tip of the N ₂ supply pipe 272. The flow path conversion unit 273 is fixed to the tip of the N ₂ supply pipe 272 by, for example, screwing. Flow path converting unit 273 converts the path of _{N 2} flowing straight in the -Z direction along the _{N 2} supply line 272 from the straight direction (-Z direction) in the diagonal direction (direction crossing the Z-axis). Thereby, the flow of N ₂ passing through the N ₂ supply pipe 272 becomes a flow toward the tip of the inner Ga supply pipe 271.

Accordingly, in this embodiment, it is possible to cross the flow direction of the N ₂ to be discharged from the liquid Ga in the flow direction and N ₂ supply pipe 272 flows out from the Ga supply pipe 271. For this reason, compared with the case where the flow-path conversion part 273 is not provided, it can suppress that Na gas evaporated from the mixed melt 12 flows in into the Ga supply piping 271. FIG. Therefore, it is possible to provide a gallium nitride manufacturing apparatus capable of suppressing the formation of miscellaneous crystals of GaN in the Ga supply pipe 271 and suppressing the blockage of the Ga supply pipe 271.

DESCRIPTION OF SYMBOLS 1,170,270 ... Gallium nitride manufacturing apparatus (crystal growth apparatus), 10 ... Reaction container, 11 ... Seed substrate, 12 ... Melt, 50 ... Ga supply source (2nd supply source), 51,171, 271 ... Ga supply pipe (second supply pipe), 51Ra ... vertical supply path, 51Rb ... inclined supply passage, 60 ... _{N 2} supply source (first source, a third source), 61,172,272 ... _{N 2} supply line ( 1st supply piping, 3rd supply piping)

Claims (4)

A reaction vessel in which nitrogen gas and a melt composed of gallium and sodium are reacted in a heated and pressurized atmosphere to grow crystals on a seed substrate immersed in the melt;
A first supply pipe for supplying the nitrogen gas to the reaction vessel;
A first supply source for supplying the nitrogen gas to the first supply pipe;
A second supply pipe for supplying the gallium to the reaction vessel;
A second supply source for supplying the gallium to the second supply pipe;
A third supply pipe for supplying an inert gas to the reaction vessel;
A third supply source for supplying the inert gas to one end of the third supply pipe,
The other end of the third supply pipe is connected to an intermediate part of the second supply pipe,
After the second supply source supplies the gallium to the reaction vessel through the second supply pipe, the third supply source supplies the inert gas through the third supply pipe and the second supply pipe. A crystal growth apparatus, wherein the crystal growth apparatus is supplied to the reaction vessel .   2. The crystal according to claim 1, wherein the first supply pipe and the third supply pipe are made of the same pipe, and the first supply source and the third supply source are made of the same supply source. Growth equipment. The second supply pipe has at least one of a vertical supply path that passes through the upper part of the reaction container and is perpendicular to the reaction container, and an inclined supply path that has a downward inclination toward the reaction container. The crystal growth apparatus according to claim 1. The crystal growth apparatus according to claim 1, wherein the second supply pipe has a tapered shape with a tapered tip .

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