JP2013112605A - Regenerating method of reaction vessel, regeneration reaction vessel, and method for producing crystal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a regenerating method of a reaction vessel used in crystal growth, a regeneration reaction vessel, and a method for manufacturing a crystal that uses the vessel, in order to provide a reaction vessel reusable in crystal growth.SOLUTION: There is provided the method for regenerating the reaction vessel that includes applying a restoring procedure that repairs deformation and/or alteration in quality of the reaction vessel generated in the method for producing a crystal to the reaction vessel having been used for the method for producing the crystal that performs the crystal growth in a supercritical state and/or a subcritical state in the presence of a raw material, a solvent and a mineralizing agent.

Description

  The present invention relates to a method for regenerating a reaction vessel used for crystal growth, particularly crystal growth utilizing an ammonothermal method, a regeneration reaction vessel regenerated by the method, and a method for producing a crystal using the same.

  A single crystal of nitride such as gallium nitride or aluminum nitride can be obtained by growing the crystal using an ammonothermal method or the like. The ammonothermal method is a method for producing a desired material using a dissolution-precipitation reaction of raw materials using a nitrogen-containing solvent such as ammonia in a supercritical state and / or a subcritical state. When applied to crystal growth, crystals are precipitated by generating a supersaturated state due to a temperature difference using the temperature dependence of the solubility of the raw material in the solvent.

  The ammonothermal method uses, for example, a solvent containing nitrogen such as ammonia in a supercritical state and / or a subcritical state in a reaction vessel such as a capsule housed in a pressure-resistant vessel such as an autoclave. This can be performed by growing crystals (see, for example, Patent Document 1). As described above, when crystal growth is performed under high temperature and high pressure, damage to the reaction vessel caused by one crystal growth is large and easily deteriorated. On the other hand, the material of the reaction vessel is mainly precious metal and is expensive. For this reason, if the reaction vessel is replaced every time crystal growth is performed, the cost is increased.

Special table 2003-511326 gazette

  However, even if the reaction vessel is simply reused, the reaction vessel once used for crystal growth often deteriorates due to deformation (expansion, crushing), rupture, crack, pinhole, embrittlement and the like. It becomes clear that the use of the reaction vessel deteriorated in this way causes problems such as leakage of liquid / gas from the reaction vessel during capsule growth (capsule leak) and coloring of the produced crystal. It was.

  Accordingly, the present inventors provide a reaction vessel regeneration method used for crystal growth, a regeneration reaction vessel, and a crystal production method using the same, in order to provide a reaction vessel that can be reused for crystal growth. For the purpose of intensive research.

  As a result, the present inventors have found that the above problem can be solved by performing a specific repair process on the reaction vessel used for crystal growth. The present invention described below has been provided based on such findings.

[1] The reaction vessel produced in the crystal production method is used in a reaction vessel used in a crystal production method in which crystals are grown in a supercritical and / or subcritical state in the presence of a raw material, a solvent, and a mineralizer. A method for regenerating a reaction vessel, wherein a regenerative reaction vessel is provided by performing a repairing process for repairing deformation and / or alteration of the reaction vessel.
[2] The method for regenerating a reaction container according to [1], wherein the repairing step includes a cutting process of excising a deformed and / or altered part of the reaction container.
[3] The method for regenerating a reaction container according to [1] or [2], wherein the repairing step includes a correction process for correcting a deformed portion of the reaction container.
[4] The method for regenerating a reaction container according to any one of [1] to [3], wherein the repairing step includes a welding process of welding another member to the reaction container.
[5] The method for regenerating a reaction vessel according to [4], wherein the welding process is arc welding.
[6] The method for regenerating the reaction container according to any one of [1] to [5], including an inspection process for the regeneration reaction container after the repair process.
[7] The method for regenerating a reaction vessel according to any one of [1] to [6], wherein the mineralizer is an acidic mineralizer.
[8] The method for regenerating a reaction vessel according to any one of [1] to [7], wherein the reaction vessel is made of a metal containing a metal having a melting point of 500 to 3500 ° C. or an alloy thereof.
[9] The method for regenerating a reaction container according to any one of [1] to [7], wherein the reaction container is made of a material containing first to third transition metals or an alloy thereof.
[10] The reaction vessel is made of a material containing platinum (Pt), iridium (Ir), gold (Au), silver (Ag), tungsten (W), molybdenum (Mo), niobium (Nb) or an alloy thereof. The method for regenerating a reaction vessel according to [9], which is configured.
[11] A regeneration reaction container obtained by the reaction container regeneration method according to any one of [1] to [10].
[12] A primary growth step in which crystal growth is performed in a supercritical and / or subcritical state in the presence of a raw material, a solvent, and a mineralizer in a reaction vessel, and deformation of the reaction vessel after the primary growth step and And / or a repair step of repairing the alteration to obtain a regeneration reaction vessel, and secondary growth in which crystal growth is performed in a supercritical and / or subcritical state in the presence of the raw material, solvent and mineralizer in the regeneration reaction vessel. A method for producing a crystal comprising: steps in this order.

  According to the method for regenerating a reaction vessel of the present invention, the deterioration (deformation (expansion, crushing), rupture, crack, pinhole, embrittlement, etc.) of the reaction vessel used at least once for crystal growth is cut and added, and welded. The reaction vessel can be regenerated and used by a repair process such as annealing.

It is a schematic diagram of the crystal manufacturing apparatus which can be used by this invention. It is a schematic diagram for demonstrating the correction process of the dent of the junction part of reaction container. It is a schematic diagram for demonstrating the correction process of dents other than the junction part of reaction container. It is a schematic diagram for demonstrating the other correction process of dents other than the junction part of reaction container. It is a schematic diagram of the apparatus which performs the process which corrects the swelling of a reaction container.

Hereinafter, the reaction container regeneration method, the regeneration reaction container, and the crystal production method using the same according to the present invention will be described.
The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In the present specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

  The method for regenerating a reaction vessel according to the present invention is the production of the crystal in a reaction vessel used in the method for producing a crystal in which crystal growth is performed in a supercritical and / or subcritical state in the presence of a raw material, a solvent and a mineralizer. A regenerative reaction vessel is prepared by performing a repairing step for repairing deformation and / or alteration of the reaction vessel generated in the method. According to the method for regenerating a reaction vessel of the present invention, the deterioration (deformation (expansion, crushing), rupture, crack, pinhole, embrittlement, etc.) of the reaction vessel used at least once for crystal growth is cut and added, and welded. The reaction vessel can be regenerated and used by a repair process such as annealing.

[Production of crystals]
(Amonothermal method)
First, a case where an ammonothermal method is used will be described as an example of a crystal manufacturing method which is a premise of the reaction vessel regeneration method. However, the crystal growth process that can be employed in the present invention is not limited to this. The “ammonothermal method” is a method for producing a desired material using a dissolution-precipitation reaction of raw materials using a nitrogen-containing solvent such as ammonia in a supercritical state and / or a subcritical state. When the ammonothermal method is applied to crystal growth, a supersaturated state is generated by a temperature difference utilizing the temperature dependence of the raw material solubility in an ammonia solvent, and mainly nitride crystals are precipitated.
Gallium nitride crystal growth by the ammonothermal method is a reaction under supercritical and / or subcritical conditions at high temperature and pressure, and further into a nitrogen-containing solvent (especially pure ammonia) in the supercritical and / or subcritical state. Since the solubility of nitride (especially gallium nitride) is extremely small, a mineralizer can be used to improve the solubility and promote crystal growth. The crystal growth is performed, for example, by placing a raw material, a seed crystal, a mineralizer, and a solvent containing nitrogen in a reaction vessel and raising the temperature in the reaction vessel to the growth temperature of the nitride single crystal. .

(Seed crystal)
As the seed crystal, a single crystal of the same type as the nitride single crystal to be grown as a growth crystal can be used. Specific examples of the seed crystal include nitride single crystals such as gallium nitride (GaN), aluminum nitride (AlN), and indium nitride (InN).
The seed crystal can be determined in consideration of solubility in a solvent and reactivity with a mineralizer. For example, as a seed crystal of GaN, a single crystal obtained by epitaxial growth on a heterogeneous substrate such as sapphire and then exfoliated, a single crystal obtained by crystal growth of Na, Li, and Bi from metal Ga as a flux, a liquid phase A single crystal obtained by homo / heteroepitaxial growth obtained by using an epitaxy method (LPE method), a single crystal produced based on a solution growth method, a crystal obtained by cutting them, and the like can be used. The specific method of the epitaxial growth is not particularly limited, and for example, a hydride vapor phase growth method (HVPE) method, a metal organic chemical vapor deposition method (MOCVD method), a liquid phase method, an ammonothermal method, or the like is adopted. be able to.

(Mineralizer)
The kind of the mineralizer is not particularly limited. The present invention can be more preferably applied when an acidic mineralizer is used. Moreover, it is possible to apply more preferably when a mineralizer containing a halogen element is used. Examples of mineralizers containing halogen elements include ammonium halide, hydrogen halide, ammonium hexahalosilicate, and hydrocarbyl ammonium fluoride, tetramethylammonium halide, tetraethylammonium halide, benzyltrimethylammonium halide, halogen Examples thereof include alkylammonium salts such as dipropylammonium halide and isopropylammonium halide, alkyl metal halides such as sodium alkyl fluoride, alkaline earth metal halides, metal halides and the like. Of these, an additive (mineralizing agent) containing a halogen element is preferably an alkali halide, an alkaline earth metal halide, a metal halide, an ammonium halide, or a hydrogen halide, more preferably a halogenated. Alkali, ammonium halide, Group 13 metal halide and hydrogen halide are particularly preferred, and ammonium halide, gallium halide and hydrogen halide are particularly preferred. These mineralizers may be used alone or in combination of two or more.

In the manufacturing method, it is possible to use a mineralizer containing no halogen element together with a mineralizer containing a halogen element. For example, it is used in combination with an alkali metal amide such as NaNH ₂ , KNH ₂ or LiNH _2. You can also. The mineralizer can be used after being purified and dried as necessary in order to prevent impurities from being mixed into the nitride crystal grown by the production method. The purity of the mineralizer is usually 95% or higher, preferably 99% or higher, more preferably 99.99% or higher.

  The molar concentration of the halogen element contained in the mineralizer with respect to ammonia is preferably 0.1 mol% or more, more preferably 0.3 mol% or more, and further preferably 0.5 mol% or more. Further, the molar concentration of the halogen element contained in the mineralizer with respect to ammonia is preferably 30 mol% or less, more preferably 20 mol% or less, and even more preferably 10 mol% or less. When the concentration is too low, the solubility of the raw material tends to decrease and the growth rate tends to decrease. On the other hand, when the concentration is too high, the solubility of the raw material becomes too high and the generation of spontaneous nuclei increases, or the degree of supersaturation becomes too high, and control tends to be difficult.

(solvent)
As a solvent used in the ammonothermal method, a solvent containing nitrogen can be used. Examples of the solvent containing nitrogen include a solvent that does not impair the stability of the grown nitride single crystal. Examples of the solvent include ammonia, hydrazine, urea, amines (for example, primary amines such as methylamine, secondary amines such as dimethylamine, tertiary amines such as trimethylamine, and ethylenediamine. Diamine) and melamine. These solvents may be used alone or in combination.

  The amount of water and oxygen contained in the solvent is desirably as small as possible, and the content thereof is preferably 1000 ppm or less, more preferably 10 ppm or less, and further preferably 0.1 ppm or less. When ammonia is used as a solvent, the purity is usually 99.9% or more, preferably 99.99% or more, more preferably 99.999% or more, and particularly preferably 99.9999% or more. .

(material)
As a raw material, a raw material containing an element constituting a nitride single crystal to be grown on a seed crystal (seed) can be used. Preferred is a polycrystalline raw material of nitride single crystal and / or a metal to be nitrided, and more preferred is gallium nitride and / or metallic gallium. The polycrystalline raw material does not need to be a complete nitride, and depending on the conditions, the group III element may contain a metal component in a metal state (zero valence). For example, the polycrystalline raw material is gallium nitride. In some cases, a mixture of gallium nitride and metal gallium is included.

  The method for producing the polycrystalline raw material is not particularly limited. For example, a nitride polycrystal produced by reacting a metal or an oxide or hydroxide thereof with ammonia in a reaction vessel in which ammonia gas is circulated can be used. In addition, as a metal compound raw material having higher reactivity, a compound having a covalent MN bond such as a halide, an amide compound, an imide compound, or galazan can be used. Furthermore, a nitride polycrystal produced by reacting a metal such as Ga with nitrogen at a high temperature and a high pressure can also be used.

  The amount of water and oxygen contained in the polycrystalline raw material used as the raw material in the present invention is preferably small. The oxygen content in the polycrystalline raw material is usually 10,000 ppm or less, preferably 1000 ppm or less, particularly preferably 1 ppm or less. The ease of mixing oxygen into the polycrystalline raw material is related to the reactivity with water or the absorption capacity. The worse the crystallinity of the polycrystalline raw material, the more active groups such as NH groups exist on the surface, which may react with water and partially generate oxides or hydroxides. For this reason, it is usually preferable to use a polycrystalline material having as high crystallinity as possible. The crystallinity can be estimated by the half width of powder X-ray diffraction. The half width of the (100) diffraction line (2θ = about 32.5 ° for hexagonal gallium nitride) is usually 0.25 ° or less, preferably It is 0.20 ° or less, more preferably 0.17 ° or less.

(Reaction vessel)
The ammonothermal method can be carried out in a reaction vessel. Although the shape of the said reaction container is not specifically limited, For example, a cylindrical capsule can be used suitably.
The reaction vessel can be selected from those capable of withstanding high temperature and high pressure conditions when growing a nitride single crystal. Examples of the reaction vessel include those described in JP-T-2003-511326 (International Publication No. 01/024921 pamphlet) and JP-T-2007-509507 (International Publication No. 2005/043638 pamphlet). It may be provided with a mechanism for adjusting the pressure applied to the reaction vessel and its contents from the outside, or may not have such a mechanism.

  The reaction vessel is preferably made of a material having pressure resistance and corrosion resistance. In particular, a Ni-based alloy having excellent corrosion resistance against a solvent such as ammonia, Stellite (registered trademark of Deloro Stellite Company, Inc.) It is preferable to use a Co-based alloy such as More preferably, it is a Ni-based alloy. Specifically, Inconel 625 (Inconel is a registered trademark of Huntington Alloys Canada Limited, the same applies hereinafter), Nimonic 90 (Nimonic is a registered trademark of Special Metals Wiggin Limited, the same applies hereinafter), RENE41 (Teledyne). Allvac, Inc.), Inconel 718 (Inconel is a registered trademark of Huntington Alloys Canada Limited), Hastelloy (registered trademark of Haynes International, Inc.), Waspaloy (registered trademark of United Technologies, Inc.).

  On the other hand, although these alloys have high corrosion resistance, they do not have such high corrosion resistance that they have no influence on the crystal quality. In these alloys, in a supercritical solvent atmosphere, particularly in a more severe corrosive environment containing a mineralizer, components such as Ni, Cr, and Fe may be dissolved in the solution and incorporated into the crystal. Therefore, in the present invention, in order to suppress internal corrosion of the pressure-resistant container made of the above-described high pressure-resistant alloy, a method of directly lining or coating the inner surface with a material having further excellent corrosion resistance, or a capsule made of a material having further excellent corrosion resistance It is preferable to form the reaction vessel by a method of arranging the inside of the pressure vessel. Among these, a method of arranging capsules as reaction vessels in a pressure-resistant vessel is preferable because of high accuracy in reducing impurities in crystals. In such a form, it is preferable to fill the second solvent between the inner wall of the pressure-resistant vessel and the outer wall of the capsule in addition to the first solvent to be filled in the reaction vessel, and the solvent is in a supercritical state during crystal growth. When the sub-critical state is reached, it is preferable that the first solvent and the second solvent maintain a pressure balance so that the capsule does not deform. However, since it is extremely difficult to maintain the balance of pressure balance by the solvent inside and outside the capsule, the capsule is likely to be deformed. Therefore, the present invention is preferable because a particularly high effect can be exhibited in an apparatus using the mechanism as described above.

  In order to suppress deformation of the capsule due to the pressure difference between the inside and outside of the capsule as much as possible, a part that is easily deformed may be formed in the capsule. By providing a portion that is easily deformed, deformation of other portions of the capsule can be suppressed. For example, when the pressure on the outside of the capsule is higher than the pressure inside the capsule, the easily deformable portion is crushed, so that the pressure inside and outside the capsule is balanced, and deformation of other portions can be minimized. On the other hand, when the pressure outside the capsule is lower than the pressure inside the capsule, the easily deformable portion expands to balance the pressure inside and outside the capsule, and deformation of other portions can be minimized. The structure of the part that is easily deformed can be easily deformed by making the strength of the material lower than other parts. As a technique for reducing the strength, it is preferable to employ a softer material and / or make the wall thickness thinner than other parts. As other structures, bellows structures can also be suitably used. The bellows structure is superior to other methods in that it is easy to control the amount of displacement and is easy to deform in both the extension and contraction directions. As will be described later, when the capsule is reused, only the deformed portion can be replaced, or only the displaced portion can be modified, which is excellent in terms of reuse efficiency and reuse cost.

  The materials of the reaction vessel suitable for reuse are the first to third transition metals and their alloys from the viewpoint of the corrosion resistance to the mineralizer used for crystal growth, the temperature during crystal growth, and the workability during regeneration treatment. Preferably, among the first to third transition metals, ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), silver More preferred are noble metals such as (Ag), and tantalum (Ta), tungsten (W), niobium (Nb), and molybdenum (Mo), and more preferred are Pt, Ir, Au, Ag, W, Mo, and Nb. Further, these materials are preferably metals having a melting point of 500 to 3500 ° C. or alloys thereof, and in particular, the melting point is preferably 1000 ° C. or more, more preferably 1500 ° C. or more. Moreover, it is preferable that it is 3400 degrees C or less, and it is more preferable that it is 3000 degrees C or less.

In particular, when an acidic mineralizer containing fluorine is used, Ag, Pt, or a Pt—Ir alloy is preferable. In the case of using an acidic mineralizer containing a halogen other than fluorine, Pt or a Pt—Ir alloy is preferable. At this time, if there is too much Ir in the alloy, it is too hard to perform the repairing process. On the other hand, Pt alone may be too soft. For this reason, it is preferable that the material has an appropriate hardness in order to efficiently regenerate the capsule.
From the above viewpoint, the Ir content of the Pt—Ir alloy is preferably 30% by weight or less, more preferably 25% by weight or less, and preferably 1% by weight or more, and 5% by weight. More preferably.

  The composition ratio of these alloys depends on the temperature and pressure conditions of the solvent in the system, and the reactivity with the mineralizers and their reactants contained in the system and / or the oxidizing power / reducing power, pH conditions, What is necessary is just to select suitably. In order to use these as materials constituting the inner surface of the reaction vessel, the reaction vessel itself may be manufactured using these alloys, or an inner cylinder (capsule) may be installed in the pressure resistant vessel as a reaction vessel. The inner surface of any reaction vessel material may be plated.

(Crystal production equipment)
A specific example of a crystal production apparatus including a reaction vessel that can be used in a method for producing a nitride single crystal is shown in FIG. FIG. 1 is a schematic view of a crystal manufacturing apparatus that can be used in the present invention. In the crystal manufacturing apparatus shown in FIG. 1, crystal growth is performed in a capsule (inner cylinder) 20 loaded as a reaction vessel in the autoclave 1. The capsule 20 includes a raw material dissolution region 9 for dissolving the raw material and a crystal growth region 6 for growing crystals. A solvent and a mineralizer can be placed in the raw material dissolution region 9 together with the raw material 8, and a seed 7 can be installed in the crystal growth region 6 by suspending it with a wire. Between the raw material melting region 9 and the crystal growth region 6, a partition baffle plate 5 is installed in two regions. The baffle plate 5 has a hole area ratio of preferably 2 to 60%, more preferably 3 to 40%. The material of the surface of the baffle plate 5 is preferably the same as the material of the capsule 20 that is a reaction vessel. Further, in order to provide more corrosion resistance and to purify the crystal to be grown, the surface of the baffle plate 5 is Ni, Ta, W, Mo, Ti, Nb, Pd, Pt, Au, Ir, and pBN. Pd, Pt, Au, Ir, and pBN are more preferable, and Pt is particularly preferable. In the crystal production apparatus shown in FIG. 1, the space between the inner wall 2 of the autoclave 1 and the outer wall 21 of the capsule 20 can be filled with the second solvent. Here, ammonia can be filled as the second solvent while filling the nitrogen gas from the nitrogen cylinder 13 through the valve 10 or confirming the flow rate from the ammonia cylinder 12 with the mass flow meter 14. In addition, the vacuum pump 11 can perform necessary pressure reduction. It should be noted that a valve, a mass flow meter, and a conduit do not necessarily have to be installed in the crystal manufacturing apparatus used when the nitride single crystal manufacturing method is carried out.

  A lining may be used to make the autoclave more corrosion resistant. The lining material is preferably at least one metal or element of Pt, Ir, Ag, Pd, Rh, Cu, Au and C, or an alloy or compound containing at least one metal, More preferably, it is an alloy or compound containing at least one or more kinds of metals or elements of Pt, Ag, Cu and C, or at least one kind of metals because they are easily lined. For example, Pt simple substance, Pt-Ir alloy, Ag simple substance, Cu simple substance, graphite, etc. are mentioned.

(Crystal growth)
The crystal growth procedure by the ammonothermal method will be described. First, a seed crystal (seed), a nitrogen-containing solvent, a raw material, and a mineralizer are put in a reaction vessel and sealed. Prior to introducing them into the reaction vessel, the reaction vessel may be deaerated. Moreover, you may distribute | circulate inert gas, such as nitrogen gas, at the time of introduction | transduction of materials. The seed is normally loaded into the reaction vessel at the same time as or after filling the raw material and the mineralizer. The seed is preferably fixed to a noble metal jig similar to the noble metal constituting the inner surface of the reaction vessel. After loading, heat deaeration may be performed as necessary.

  When the production apparatus shown in FIG. 1 is used, a capsule, which is a pressure vessel (autoclave), is sealed after a seed, a nitrogen-containing solvent, a raw material, and a mineralizer are sealed in the capsule 20 which is a reaction vessel. 1, and the second solvent is preferably filled in the space between the pressure vessel and the reaction vessel, and the pressure vessel is sealed.

  Thereafter, the whole is heated to bring the inside of the reaction vessel into a supercritical state and / or a subcritical state. In the supercritical state, the viscosity is generally low and it is more easily diffused than the liquid, but has the same solvating power as the liquid. The subcritical state means a liquid state having a density substantially equal to the critical density near the critical temperature. For example, in the raw material filling part, the raw material is melted in a supercritical state, and in the crystal growth part, the temperature is changed so that it becomes a subcritical state, and crystal growth using the difference in solubility between the supercritical state and the subcritical state raw material is also performed. Is possible.

  When in the supercritical state, the reaction mixture is generally maintained at a temperature above the critical point of the solvent. When an ammonia solvent is used, the critical point is a critical temperature of 132 ° C. and a critical pressure of 11.35 MPa. However, if the filling rate with respect to the volume of the reaction vessel is high, the pressure far exceeds the critical pressure even at a temperature below the critical temperature. In the present invention, the “supercritical state” includes such a state exceeding the critical pressure. Since the reaction mixture is enclosed in a constant volume reaction vessel, the increase in temperature increases the pressure of the fluid. In general, if T> Tc (critical temperature of one solvent) and P> Pc (critical pressure of one solvent), the fluid is in a supercritical state.

  Under supercritical conditions, a sufficient growth rate of the nitride single crystal can be obtained. The reaction time depends in particular on the reactivity of the mineralizer and the thermodynamic parameters, ie temperature and pressure values. During the synthesis or growth of the nitride single crystal, the pressure in the reaction vessel is preferably 120 MPa or more, more preferably 150 MPa or more, and further preferably 180 MPa or more. The pressure in the reaction vessel is preferably 700 MPa or less, more preferably 500 MPa or less, further preferably 350 MPa or less, and particularly preferably 300 MPa or less. The pressure is appropriately determined depending on the filling rate of the solvent volume with respect to the temperature and the volume of the reaction vessel. Originally, the pressure in the reaction vessel is uniquely determined by the temperature and the filling rate, but in reality, the raw materials, additives such as mineralizers, temperature heterogeneity in the reaction vessel, and free volume Depending on the presence of

  The lower limit of the temperature range in the reaction vessel is preferably 500 ° C or higher, more preferably 515 ° C or higher, and further preferably 530 ° C or higher. The upper limit value is preferably 700 ° C. or lower, more preferably 650 ° C. or lower, and further preferably 630 ° C. or lower. When producing a nitride single crystal, it is preferable that the temperature of the raw material dissolution region in the reaction vessel is higher than the temperature of the crystal growth region. The temperature difference (| ΔT |) between the raw material dissolution region and the crystal growth region is preferably 5 ° C. or higher, more preferably 10 ° C. or higher, from the viewpoint of maintaining crystal quality and controlling the spontaneous nucleation crystals. Preferably, it is 100 ° C. or less, more preferably 80 ° C. or less, and particularly preferably 60 ° C. or less. The optimum temperature and pressure in the reaction vessel can be appropriately determined depending on the type and amount of mineralizer and additive used during crystal growth.

  In order to achieve the above temperature range and pressure range in the reaction vessel, the injection rate of the solvent into the reaction vessel, that is, the filling rate is the free volume of the reaction vessel, that is, when the polycrystalline raw material and seed are used in the reaction vessel Subtract the volume of the seed and the structure where it will be installed from the volume of the reaction vessel. Based on the liquid density at the boiling point of the solvent of the volume to be used, it is usually 20 to 95%, preferably 30 to 80%, more preferably 40 to 70%.

  Nitride single crystal growth in a reaction vessel is performed by heating the reaction vessel with an electric furnace having a thermocouple or the like to bring the reaction vessel into a subcritical or supercritical state of a solvent such as ammonia. This is done by holding. The heating method and the rate of temperature increase to a predetermined reaction temperature are not particularly limited, but are usually performed over several hours to several days. If necessary, the temperature can be raised in multiple stages, or the temperature raising speed can be changed in the temperature range. It can also be heated while being partially cooled.

  The “reaction temperature” is measured by a thermocouple provided so as to be in contact with the outer surface of the reaction vessel and / or a thermocouple inserted into a hole having a certain depth from the outer surface. It can be estimated in terms of temperature. The average value of the temperatures measured with these thermocouples is taken as the average temperature.

  The reaction time after reaching a predetermined temperature varies depending on the type of nitride single crystal, the raw material used, the type of mineralizer, and the size and amount of the crystal to be produced, but is usually several hours to several hundred days. can do. During the reaction, the reaction temperature may be constant, or the temperature may be gradually raised or lowered. Moreover, you may change the temperature difference of a raw material melt | dissolution area | region and a crystal growth area | region during reaction. After a reaction time for producing desired crystals, the temperature is lowered. The temperature lowering method is not particularly limited, but the heating may be stopped while the heating of the heater is stopped and the reaction vessel is installed in the furnace as it is, or the reaction vessel may be removed from the electric furnace and air cooled. If necessary, quenching with a refrigerant is also preferably used.

After the temperature of the outer surface of the reaction vessel or the estimated temperature inside the reaction vessel is below a predetermined temperature, the reaction vessel is opened. The predetermined temperature at this time is not particularly limited, and is usually −80 ° C. to 200 ° C., preferably −33 ° C. to 100 ° C. Here, the valve may be opened by connecting a pipe to the pipe connection port of the valve attached to the reaction vessel, leading to a vessel filled with water or the like. Furthermore, if necessary, the ammonia solvent in the reaction vessel is sufficiently removed by making a vacuum or the like, and then dried, and the nitride single crystal formed by opening the reaction vessel lid, etc. and unreacted raw materials and ores Additives such as an agent can be taken out.
In addition, when manufacturing a gallium nitride by an ammonothermal method, Unexamined-Japanese-Patent No. 2009-263229 can be referred preferably for the detail of materials other than the above, manufacturing conditions, a manufacturing apparatus, and a process. The entire disclosure of this publication is incorporated herein by reference.

[Regeneration of reaction vessel]
(Feature)
Next, a method for regenerating the reaction vessel will be described. Hereinafter, in the case of “deformation” of the reaction vessel, in addition to deformation of the shape of the reaction vessel, cutting when the crystal is taken out from the reaction vessel is included. In addition, in the case of “degeneration” of the reaction vessel, contamination of the reaction vessel surface with oxygen or the like is included.
According to the method for regenerating a reaction vessel of the present invention, by performing a repair process on the reaction vessel used for crystal growth using the ammonothermal method or the like, the reaction vessel is restored so that it can be used again for crystal growth. Can be made. In the repairing step, for example, the reaction container is repaired by returning the deformed diameter of the reaction container to the original size (sizing) or correcting the warp by applying a force to the reaction container.

  Specifically, in the repairing step, the following cleaning process, cutting process, (diameter) correction process, end face processing process, welding process, heat treatment, and the like can be performed. Hereinafter, in this specification, processes involving deformation of the reaction vessel during a repair process such as a cutting process, a correction process, and an end face processing process may be collectively referred to as a regeneration process.

(Cleaning process)
First, the reaction vessel used for crystal growth is preferably subjected to a cleaning treatment in order to remove raw materials such as mineralizer and polycrystalline GaN attached to the inner wall during crystal growth. In the cleaning treatment, acid, alkali, or the like can be used. The concentration or temperature condition of the acid or alkali used at this time can be appropriately selected. For example, hydrochloric acid, nitric acid, sulfuric acid, oxalic acid, hydrofluoric acid, acetic acid, aqua regia, phosphoric acid, hydrogen peroxide, a mixed acid thereof can be used as the acid, and potassium hydroxide, sodium hydroxide, Ammonia can be used. The acid or alkali concentration can be used in the range of 1 to 100 mol%, and is preferably 5 mol% or more and more preferably 10 mol% or more because of its high detergency. The temperature of the acid or alkali to be used can be in the range of 0 to 200 ° C., and is preferably 10 ° C. or higher because of its high detergency, more preferably 20 ° C. or higher, and safety during handling. From the reason of property, it is preferable that it is 150 degrees C or less, and it is more preferable that it is 100 degrees C or less.

  In addition, after washing the inside of the reaction vessel with acid or alkali, it is preferable to rinse with pure water or the like in order to prevent these washing solutions from remaining on the vessel surface. Furthermore, after washing, drying in an oven or natural drying is preferred so that no moisture remains in the reaction vessel. In addition, it is preferable to perform the said washing | cleaning process ahead of other processes, such as the cutting process mentioned later, a correction process, and a joining process.

The said washing process can be performed in the following procedures, for example.
(1) Cleaning with dilute hydrochloric acid (for example, concentration 5% by weight, ultrasonic wave, 1 hour)
(2) Rinsing with pure water (3) Cleaning with potassium hydroxide (for example, concentration 45% by weight, temperature 120 ° C., 12 hours)
(4) Rinsing with pure water (5) Oven drying The step (1) may be any cleaning that can mainly remove metal impurities. In addition to dilute hydrochloric acid, immersion cleaning with an acidic solution such as hydrochloric acid, sulfuric acid, nitric acid, etc. Ultrasonic cleaning or the like may be used. The step (2) may be any cleaning that can remove crystals such as attached gallium nitride. In addition to potassium hydroxide, a strong alkaline solution such as sodium hydroxide, high-temperature (about 230 ° C.) phosphoric acid, It may be immersion cleaning with a high temperature acid solution such as sulfuric acid or a mixed acid of phosphoric acid and sulfuric acid.

(Cutting process)
After using for crystal growth, if the reaction vessel has pinholes or cracks, or if the shape of the reaction vessel is greatly deformed and difficult to regenerate, use a tube cutter or a cutting machine to cut the markedly deteriorated area. Then, the defective portion can be removed. That is, in the repairing step, a cutting process for excising a deformed and / or altered part of the reaction vessel can be performed. Further, when the total length of the reaction vessel is insufficient due to the cutting, a regeneration reaction vessel can be produced by adding a capsule tube having a necessary length by welding as described later. The cutting process is preferably performed prior to the following correction process or the like because the diameter of the reaction vessel may vary during cutting.

  When using a capsule having a part that is easily deformed in order to maintain the pressure balance inside and outside the capsule, it is preferable to remove only the part that is easily deformed by cutting. Moreover, when it has a bellows structure, it is preferable to excise only the site | part of a bellows structure and to replace with a new bellows structure, and to manufacture a reproduction | regeneration reaction container.

(Correction treatment)
When a dent or bulge occurs in the reaction vessel after use for crystal growth, it is preferable to correct the diameter as necessary. In particular, when the reaction container is cut and added, it is necessary to adjust the diameter of the joint port of each member to be added, and therefore it is preferable to correct the diameter. That is, the repairing step may include a correction process for correcting a deformed portion of the reaction container. On the other hand, when there are irregularities at locations other than the joint of the reaction vessel, it is not always necessary to correct (recover irregularities) if there is no effect on the insertion or operation of other structures in the reaction vessel.

A. When correcting a dent A case where a dent of a cutting port (joining port) generated when a reaction vessel is cut using a tube cutter or a cutting machine is corrected will be described. In this case, for example, as shown in FIG. 2, a part of the cylinder 102 whose diameter is 0.5 mm or more smaller than the inner diameter of the reaction vessel 100 is inserted into the recessed portion 104 of the reaction vessel 100. Next, as shown in FIG. 2, the reaction vessel 100 in which the cylinder 102 is inserted is set in a mold 106 that is a semi-cylinder having the same inner diameter as the outer diameter of the reaction vessel 100. Thereafter, a load is applied to the cylinder 102 from the direction P1 in FIG. 2 (the cylinder 102 is hit with a hammer) to repair the recess 104 of the reaction vessel 100, and the inner diameter of the joint of the reaction vessel 100 is set to a desired shape. Can be corrected.

  Next, a description will be given of the case of correcting (repairing) a dent in a portion (for example, an abdominal portion) other than the joint of the reaction vessel. In this case, for example, as shown in FIG. 3, the cylinder 102 having a diameter of 0.5 mm or more smaller than the inner diameter of the reaction vessel 100 is pushed in until the dent 108 formed in the abdomen of the reaction vessel 100 is reached. . Further, after the cylinder 102 is inserted into the reaction vessel 100, it is set in a mold 106 that is a semi-cylinder having the same inner diameter as the outer diameter of the reaction vessel 100. Thereafter, for example, by applying a load to the cylinder 102 from the direction P2 in FIG. 3 (hitting the cylinder 102 with a hammer or the like), the recess 108 of the reaction vessel 100 is repaired, and the reaction vessel 100 is corrected to a desired shape. be able to.

  Further, as shown in FIG. 4, the reaction vessel 100 in which the cylinder 102 is completely inserted is set in the mold 106, and the reaction vessel is further set in the mold 107 which is the same type as the mold 106 and is paired therewith. 100, and then applying a load to the molds 106 and 107 from the direction of P3 in FIG. 4 (hitting the molds 106 and 107 with a hammer etc.) repairs the recess 108 of the reaction container 100, and the reaction container 100 Can be corrected to a desired shape.

B. When correcting the swelling When the reaction vessel is used for crystal growth, the reaction vessel may swell due to the pressure from the inside, and the inner diameter of the reaction vessel may increase. When correcting such swelling of the reaction vessel, for example, as in the case shown in FIG. 4 described above, the reaction vessel 100 in which the cylinder 102 is completely inserted is set in the mold 106, and further the gold The reaction vessel 100 is sandwiched between molds 107 that are the same as the mold 106 and paired with the mold 106, and then a load is applied to the molds 106 and 107 (by hitting the molds 106 and 107 with a hammer or the like). Swelling can be corrected.

  Moreover, for example, as shown in FIG. 5, the bulge of the reaction vessel can be corrected by using a multi-stage roll type bulge correction apparatus including a plurality of rolls 110. At this time, the number of rolls in the apparatus is not particularly limited, but if the roll for correcting the reaction container is an apparatus having only one upper and lower (or left and right) reaction containers, the swelling of the reaction container can be corrected. It is difficult to correct the warp when the reaction vessel is warped. For this reason, it is preferable that the said correction | amendment apparatus is an apparatus arrange | positioned so that it may have three or more rolls and the said roll can correct the curvature of the reaction container while correcting the curvature. In the apparatus shown in FIG. 5, by moving the reaction vessel 100 in the P direction, the reaction vessel 100 is pressed by the roll 110, thereby correcting the swelling of the reaction vessel 100 and correcting the warpage. .

(End face processing)
As described above, when the reaction vessel used for crystal growth is cut and the missing portion is welded and added, end surface processing (tube squaring) is performed on each joint before welding, and the gap between the joints It is preferable to make welding as easy as possible. As the end face processing, a known method can be appropriately employed.

(Welding process)
As described above, when the reaction vessel used for crystal growth is cut, a welding process for welding another member to the reaction vessel can be performed. In the case where the lacking portion is welded and added to the reaction vessel, it is preferable to join the added portion by arc welding or the like. In this case, it is preferable to perform diameter correction and end face processing of the capsule joint in advance by the method described above.
Moreover, when the capsule has a pinhole or a crack, the hole can be filled by arc welding.

(Inspection process)
After performing the repair process on the reaction vessel as described above, there are no pinholes or minute cracks remaining in the repaired (regenerated) reaction vessel (hereinafter referred to as the regeneration reaction vessel) (leakage). It is preferable to carry out an inspection step such as whether the diameter of the check is appropriate or whether there is dirt. Examples of the leak check method include a vacuum standing method, a helium leak test method, a pressure foaming method, an underwater foaming method, and a color check method.

(Post-cleaning treatment)
It is preferable to wash the repaired (regenerated) reaction container (regenerated reaction container) in order to remove the dirt adhered by the regeneration process after performing the repair process on the reaction container as described above. As such a cleaning treatment, an organic solvent (for example, isopropyl alcohol) is used to remove processing oil and hand dust, and an acid such as hydrochloric acid and sulfuric acid (especially strong acid is preferred) to remove metal stains. Can be used. Also in the post-cleaning treatment, it is preferable to rinse with pure water or the like in order to prevent these cleaning liquids from remaining on the surface of the container. Furthermore, after washing, drying in an oven or natural drying is preferred so that no moisture remains in the reaction vessel.

The said washing process can be performed in the following procedures, for example.
(1) Washing with isopropyl alcohol (2) Rinsing with pure water (3) Washing with 37 wt% hydrochloric acid (4) Rinsing with pure water (5) Drying in oven The above step (1) is mainly degreasing. In addition to isopropyl alcohol, immersion cleaning or ultrasonic cleaning with an organic solvent such as ethanol, methanol or acetone, or a solution containing a surfactant may be used, or high-temperature steam may be sprayed. It is valid. Moreover, the said process (2) should just be the washing | cleaning which can remove a metal impurity, and besides hydrochloric acid, you may use nitric acid, a sulfuric acid, an acetic acid, phosphoric acid, and these mixed acids.

(Heat treatment)
The capsule material repeatedly used (for example, four times or more) in a solvent containing nitrogen such as high-temperature and high-pressure ammonia may be increasingly brittle depending on the method of use. For this reason, if this is reused, cracks are likely to occur in the capsule due to pressure changes inside and outside the capsule during crystal growth. In contrast, when heat treatment (annealing) is performed on the regeneration reaction vessel before crystal growth, embrittlement that has occurred in the regeneration reaction vessel during the growth process or regeneration treatment can be recovered. Moreover, after crystal growth, the reaction vessel may be embrittled by hydrogen. Even in this case, it can be expected that the embrittlement due to hydrogen is recovered by applying heat treatment to the reaction vessel.
For this reason, the capsule material used repeatedly (for example, 4 times or more) can further reduce the embrittlement of the capsule material by controlling the conditions during the heat treatment. Specifically, the temperature is preferably 500 ° C. or higher, and more preferably 600 ° C. or higher. The time is preferably 0.5 hours or more, and more preferably 1 hour or more. The pressure is preferably atmospheric pressure, but may be under reduced pressure. Moreover, although it is preferable to carry out in inert gas atmosphere, you may be in air | atmosphere.

(Reuse)
As described above, the regeneration reaction container regenerated by the reaction container regeneration method of the present invention leaks gas or liquid from the reaction container even when it is used again for crystal growth by the ammonothermal method or the like (capsule There is no leakage), and it is possible to suppress the crystals produced by impurities derived from the reaction vessel surface from being colored.
That is, if the regeneration method of the present invention is used, first, crystal growth is performed in a supercritical and / or subcritical state in the presence of a raw material, a solvent and a mineralizer in a reaction vessel (primary growth step), Thereafter, after the primary growth step, deformation and / or alteration of the reaction vessel is repaired to obtain a regeneration reaction vessel, and again in the presence of the raw material, solvent and mineralizer in the regeneration reaction vessel. Crystal growth can be performed in a critical and / or subcritical state (secondary growth step).

  The features of the present invention will be described more specifically with reference to examples and comparative examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below. In the examples, reference examples and comparative examples described below, an attempt was made to grow a nitride single crystal using the reaction apparatus shown in FIG.

[Example 1]
(Reuse the capsule by applying a restoration process)
Using the RENE41 autoclave 1 as a pressure-resistant vessel, a Pt-Ir capsule (Ir content 10%) 20 once used for crystal growth under the same conditions as in this example as a reaction vessel was repaired by the following procedure. What was reproduced by applying. Crystal growth using this capsule is convenient for the second time. The capsule 20 has a cylindrical shape with an inner diameter of 25 mm and a length of 330 mm. A raw material, a mineralizer, a baffle plate, a plate-like seed crystal having a C-plane or M-plane as a main surface was placed in a capsule, and NH ₃ was filled as a liquid corresponding to about 55% of the void volume of the capsule. Subsequently, after the capsule was inserted into the autoclave equipped with the valve 10, the lid was closed and NH ₃ was filled.
Subsequently, the autoclave 1 was stored in an electric furnace. The temperature of the crystal growth region (growth region) 6 on the outer surface of the autoclave is increased to 610 ° C., and the temperature of the raw material dissolution region (raw material region) 9 is increased to 610 ° C. Hold for 9 days. The pressure in the autoclave was about 215 MPa. Further, the variation in the control temperature of the outer surface of the autoclave during the holding was ± 0.3 ° C. or less.
Thereafter, the temperature of the outer surface of the autoclave 1 is naturally cooled to return to room temperature, remove the NH ₃ in the autoclave. Subsequently, the lid of the autoclave was opened, and the capsule 20 was taken out. When the appearance of the capsule was observed, no abnormality was confirmed. Furthermore, as a result of measuring the weight of the capsule, it was confirmed that the capsule weight was the same as that before the crystal growth, and the capsule did not leak. When the upper part of the capsule was cut into two parts and the inside of the capsule was confirmed, gallium nitride crystals were uniformly deposited on the entire surface of the seed crystals on both the C and M faces. Through the above steps, the gallium nitride crystal of Example 1 was obtained.

(Repair process)
The restoration process was carried out by the following method, and the capsules used for crystal growth were regenerated.

・ Cleaning 1
In order to remove the mineralizer and polycrystalline GaN raw material adhering to the inner wall of the previously used capsule, the capsule was washed in the following procedure.
(1) Cleaning with dilute hydrochloric acid (concentration 5% by weight, ultrasonic wave, temperature 20 (room temperature) ° C., 1 hour)
(2) Rinsing with pure water (3) Cleaning with potassium hydroxide (concentration 45% by weight, temperature 120 ° C., 12 hours)
(4) Rinsing with pure water (5) Drying in an oven (temperature 45 ° C., 4 hours)

・ Straightening / welding process (regeneration process)
Next, the previously used capsule was cut at a location 100 mm from the end. In addition, the concave portions and warpage of the capsule were corrected by the method shown in FIGS. 2 and 5 described above. Thereafter, end surfaces (tube squaring) were applied to the joint, and a cylinder having an inner diameter of 25 mm, a length of 100 mm, and a material Pt—Ir (Ir content: 10%) was joined by arc welding. Next, a leak check was performed by an underwater foaming method.

・ Cleaning 2
Subsequently, in order to remove the dirt adhering to the regeneration process, the regenerated capsules were washed by the following procedure.
(1) Cleaning with isopropyl alcohol (concentration 99.9% by weight, temperature 20 (room temperature) ° C., 0.5 hour)
(2) Rinsing with pure water (3) Washing with 37% by weight hydrochloric acid (temperature 20 (room temperature) ° C., 1 hour)
(4) Rinsing with pure water (5) Drying in an oven (temperature 45 ° C., 4 hours)

[Comparative Example 1]
In Comparative Example 1, a Pt—Ir capsule once used for crystal growth was used as a reaction vessel without being regenerated. Crystal growth using this capsule is convenient for the second time. When the appearance of the capsule was observed, a dent was generated in part of the crystal growth region (growth region) side. Further, a gallium nitride crystal was deposited on the seed crystal in the same manner as in the procedure of Example 1 except that the mineralizer concentration, pressure, and temperature were changed to the conditions shown in Table 1. When the appearance of the capsule was observed after the crystal growth, a crack was generated in the portion where the dent was generated at the first use. Furthermore, as a result of measuring the weight of the capsule, it was about 50 g less than the weight before crystal growth. This is consistent with the weight of NH ₃ were filled into capsules, NH ₃ in the capsule when removing the NH ₃ in the autoclave from cracked portion of the capsule is also considered to have gone missing. Further, since the precipitated gallium nitride crystal is more colored than the crystal of Example 1, it is considered that more impurities were taken into the crystal and the crystal quality deteriorated due to the leakage of the capsule during crystal growth. It is done.

[Reference Example 1]
In Reference Example 1, a new Pt-Ir capsule that was never used for crystal growth was used as the reaction vessel. Further, a gallium nitride crystal was deposited on the seed crystal in the same manner as in the procedure of Example 1 except that the mineralizer concentration, pressure, and temperature were changed to the conditions shown in Table 1. When the appearance of the capsule was observed after the crystal growth, a dent was generated in a part on the crystal growth region (growing region) side. Furthermore, as a result of measuring the weight of the capsule, it was confirmed that the capsule weight was the same as that before the crystal growth, and the capsule did not leak. Further, the deposited gallium nitride had the same yellow-green color as in Example 1, and was thinner than the crystal of Comparative Example 1.

  From the results of Example 1, Comparative Example 1, and Reference Example 1, the capsules that had undergone crystal growth under high temperature and high pressure were repeatedly used as they were without a repairing process that was subjected to a regeneration process because deformation such as expansion and dents occurred. Although it leaks easily, it can be reused without leaking by performing the capsule regeneration process with the capsule regeneration method described above, and crystals with the same quality (impurity level) as in the case of a new capsule can be obtained. I understood that.

[Example 2]
In Example 2, a Pt-Ir capsule used three times for crystal growth as a reaction vessel was regenerated by the same capsule regeneration method as in Example 1, and then heat treatment (annealing) was performed to complete the repairing process. To do. Crystal growth using this capsule is convenient for the fourth time. Further, the gallium nitride crystal is deposited on the seed crystal in the same manner as in the procedure of Example 1 except that the mineralizer concentration, pressure, and temperature are changed to the conditions shown in Table 1 and annealing is performed. There is no leak in the capsule after crystal growth, and the deposited gallium nitride is colored in the same degree as in Example 1 and Reference Example 1.

(Annealing conditions)
Temperature: 500 ° C
Time: 0.5 hours Pressure: Atmospheric pressure Atmosphere: Under inert gas (nitrogen gas)

[Example 3]
In Example 3, the capsules used for crystal growth after heat treatment in Example 2 are regenerated by the same capsule regeneration method as in Example 1, and the repair process is completed without annealing. Crystal growth using this capsule is convenient for the fifth time. Further, a gallium nitride crystal is deposited on the seed crystal in the same manner as in the procedure of Example 1 except that the mineralizer concentration, pressure, and temperature are changed to the conditions shown in Table 1. There is no leak in the capsule after crystal growth, and the deposited gallium nitride is colored in the same degree as in Example 1 and Reference Example 1.
When the capsule is reused over 5 times or more, it is preferable to perform the heat treatment at least once because leakage due to embrittlement of the capsule can be more effectively prevented.

DESCRIPTION OF SYMBOLS 1 Autoclave 2 Autoclave inner wall 5 Baffle plate 6 Crystal growth area 7 Seed crystal 8 Raw material 9 Raw material melting area 10 Valve 11 Vacuum pump 12 Ammonia cylinder 13 Nitrogen cylinder 14 Mass flow meter 20 Capsule 100 Reaction vessel 102 Cylinder 104 Recess 106 Mold 107 Mold 108 Recess 110 Roll

Claims (12)

  The reaction vessel used in the method for producing a crystal that grows crystals in a supercritical and / or subcritical state in the presence of a raw material, a solvent and a mineralizer, and the deformation of the reaction vessel generated in the method for producing the crystal and A method for regenerating a reaction vessel, characterized in that a regenerative reaction vessel is provided by performing a repairing process for repairing alteration.   The method for regenerating a reaction container according to claim 1, wherein the repairing step includes a cutting process for excising a deformed and / or altered part of the reaction container.   The method for regenerating a reaction container according to claim 1, wherein the repairing step includes a correction process for correcting a deformed portion of the reaction container.   The method for regenerating a reaction container according to any one of claims 1 to 3, wherein the repairing step includes a welding process of welding another member to the reaction container.   The method for regenerating a reaction vessel according to claim 4, wherein the welding process is arc welding.   The method for regenerating a reaction vessel according to any one of claims 1 to 5, further comprising an inspection step for the regenerative reaction vessel after the repairing step.   The method for regenerating a reaction vessel according to any one of claims 1 to 6, wherein the mineralizer is an acidic mineralizer.   The said reaction container is a regeneration method of the reaction container as described in any one of Claims 1-7 comprised with the material of melting | fusing point of 500-3500 degreeC or the material containing these alloys.   The said reaction container is a regeneration method of the reaction container as described in any one of Claims 1-7 comprised with the material containing the 1st-3rd transition metal or these alloys.   The reaction vessel is made of a material containing platinum (Pt), iridium (Ir), gold (Au), silver (Ag), tungsten (W), molybdenum (Mo), niobium (Nb) or an alloy thereof. The method for regenerating a reaction container according to claim 9.   The regeneration reaction container obtained by the regeneration method of the reaction container as described in any one of Claims 1-10.   A primary growth step in which crystal growth is performed in a supercritical and / or subcritical state in the presence of a raw material, a solvent and a mineralizer in a reaction vessel, and deformation and / or alteration of the reaction vessel after the primary growth step. A recovery step of obtaining a regeneration reaction vessel by repairing, and a secondary growth step of performing crystal growth in the supercritical and / or subcritical state in the presence of the raw material, solvent and mineralizer in the regeneration reaction vessel, In this order.