JP4609207B2 - Periodic table group 13 metal nitride crystal manufacturing method and semiconductor device manufacturing method using the same - Google Patents

Description

  The present invention relates to a method for producing a nitride crystal of a Group 13 (hereinafter simply referred to as Group 13) metal such as a GaN crystal, and a method for producing a semiconductor device using the production method.

  A compound crystal of a Group 13 metal typified by gallium nitride (GaN) and nitrogen is useful as a material used in a light emitting diode, a laser diode, an electronic device for high frequency, and the like. At present, in the case of GaN, the GaN crystal size produced by a known method is about 10 mm (see Non-Patent Document 1), and its application to semiconductor devices is insufficient. As a practical method for producing a GaN crystal, a method of performing vapor phase epitaxial growth by MOCVD (Metal-Organic Chemical Vapor Deposition) method on a substrate such as a sapphire substrate or silicon carbide has been proposed (for example, non-patent) Reference 2).

  However, in the above method, since the GaN crystal is epitaxially grown on different substrates having different lattice constants and thermal expansion coefficients, the obtained GaN crystal has many lattice defects. When such a GaN crystal having many lattice defects is used, the operation of the electronic device is adversely affected, and satisfactory performance for use in an application field such as a blue laser cannot be expressed. For this reason, in recent years, it has been strongly desired to improve the quality of GaN crystals grown on a substrate and to establish a manufacturing technique for GaN bulk single crystals.

Currently, the heteroepitaxial GaN crystal growth method by the vapor phase method requires a complicated and long process in order to reduce the defect concentration of the GaN crystal. For this reason, recently, vigorous research has been conducted on crystallization of GaN, and a high pressure method in which nitrogen and Ga are reacted at high temperature and high pressure (see Non-Patent Document 3), and Ga and NaN ₃ are reduced in pressure. (Non-Patent Document 4), a flux growth method (see Non-Patent Documents 1, 5, and 6), and the like have been proposed. Alkali metal is often used for the flux, but the crystal growth rate is slow and a plate-like crystal having a size of about 10 mm is obtained. There are many unclear points such as the cause of crystal growth stopping. On the other hand, attempts have been made to generate GaN by oxidizing nitrogen ions on the Ga surface used as an electrode in molten salt (see Non-Patent Document 7), but the process leading to industrialization has not been established. Furthermore, a method for synthesizing GaN by the ammonothermal method (see Non-Patent Document 8) has also been reported, but there are problems with the crystal size and the number of lattice defects, and it has not been industrialized.
Applied Physics Vol.71 No.5 (2002) 548 J. Appl. Phys. 37 (1998) 309 J. Crystal Growth 178 (1977) 174 J. Crystal Growth 218 (2000) 712 J. Crystal Growth 260 (2004) 327 Metal Vol.73 No.11 (2003) 1060 Abstracts of 29th Molten Salt Chemistry Conference (1997), p. 11 Acta Physica Polonica A Vol.88 (1995) 137

  As described above, a group 13 metal nitride crystal with few lattice defects cannot be obtained by a heteroepitaxial crystal growth method on a substrate by a vapor phase method. Furthermore, other methods using high pressure require a large apparatus and are not economical. Furthermore, in the ammonothermal method using supercritical ammonia, the equipment and materials used are very expensive.

  The present invention has been made to solve such problems of the prior art, and an object of the present invention is to produce a Group 13 metal nitride crystal such as a high-quality GaN crystal even at a low pressure or normal pressure. It is to provide a method that can do this.

  Furthermore, another object of the present invention is to provide a method for manufacturing a semiconductor device such as a light emitting diode, a laser diode, and a high frequency electronic device using the above manufacturing method.

  In view of the above-mentioned problems, the present inventors grow a high-quality metal nitride crystal having a crystal size that can be used industrially and can be applied to a semiconductor device by an economical method. The method has been intensively studied and the present invention has been completed.

That is, the object of the present invention is achieved by the following Group 13 metal nitride crystal production method.
[1] A liquid phase (A) containing a Group 13 metal element, a liquid phase (b1) obtained by dissolving a nitride containing a metal element other than Group 13 in a molten salt, or a Group 13 metal element and A metal other than the Group 13 metal produced by the reaction with the phase (B) of either the solid phase (b2) or the liquid phase (b3) containing the composite nitride containing a metal element other than Group 13 A method for producing a Group 13 metal nitride crystal, wherein a Group 13 metal nitride crystal is grown by advancing while removing a by-product containing an element from the reaction field.
[2] The method for producing a Group 13 metal nitride crystal according to [1], wherein the by-product is removed from the reaction field by moving into the liquid phase (A).
[3] The method for producing a Group 13 metal nitride crystal according to [1] or [2], wherein the liquid phase (A) can be alloyed with the by-product.
[4] The thirteenth aspect according to any one of [1] to [3], wherein the liquid phase (A) and the liquid phase (b1) are reacted while maintaining a separated state. Group metal nitride crystal manufacturing method.
[5] The group 13 metal nitriding according to any one of [1] to [4], wherein the liquid phase (A) and the liquid phase (b1) are reacted while being alternately contacted. Method for producing physical crystals.
[6] The liquid phase (b3) is formed between the liquid phase (A) and the solid phase (b2), according to any one of [1] to [3] A method for producing a group 13 metal nitride crystal.
[7] The method according to any one of [1] to [6], wherein the by-product is removed from the reaction field via the liquid phase (A) by an electrochemical reaction. A method for producing a group 13 metal nitride crystal.
[8] The method for producing a Group 13 metal nitride crystal according to [7], wherein in the cathode reaction of the electrochemical reaction, the by-product is reacted with nitrogen gas to form a nitride.
[9] The method for producing a Group 13 metal nitride crystal according to [7], wherein in the cathode reaction of the electrochemical reaction, the by-product is alloyed with a metal element contained in the cathode electrode.
[10] Any one of [1] to [6], wherein the by-product is removed from the liquid phase (A) by reacting the liquid phase (A) with a halogen or halide gas. A method for producing a Group 13 metal nitride crystal according to one item.
[11] The group 13 metal nitride crystal according to any one of [1] to [6], wherein the crystal is grown on a seed crystal surface or a substrate in the vicinity of the reaction field. Production method.
[12] The Group 13 metal according to any one of [1] to [11], wherein the Group 13 metal nitride crystal is grown using a container containing magnesium oxide or calcium oxide. A method for producing a nitride crystal.
[13] The production of a Group 13 metal nitride crystal as described in any one of [1] to [12], wherein the metal element other than the Group 13 is an alkali metal or an alkaline earth metal. Method.
[14] The method for producing a Group 13 metal nitride crystal according to any one of [1] to [5] or [7] to [13], wherein the molten salt is a metal halide. .
[15] The liquid phase (A) and / or the liquid phase (b1) contains a simple substance or a compound containing a dopant element, as described in any one of [1] to [14] A method for producing a Group 13 metal nitride crystal.

  Another object of the present invention is achieved by a semiconductor device manufacturing method including a step of manufacturing a Group 13 metal nitride crystal by the manufacturing method according to any one of the above [1] to [15].

  According to the production method of the present invention, a high-quality Group 13 metal nitride bulk crystal can be produced even at low pressure or normal pressure. In particular, when growing a Group 13 metal nitride crystal by reacting a Group 13 metal alloy with an ionized nitrogen source preferably dissolved in a molten salt or a Group 13 metal, the crystal By controlling the metal composition in the group 13 metal alloy within a certain range, a thick film or bulk crystal can be produced efficiently. As a result, according to the present invention, the refractory material made of an oxide of alkaline earth metal or Zr, Ti, Y, Ce, etc., without the high temperature and high pressure process as in the prior art, and the reaction vessel, particularly, Using a container of an inexpensive basic refractory material such as magnesium oxide, calcium oxide or zirconia, a Group 13 metal nitride crystal having a size sufficient for application to a semiconductor device can be produced.

  The method for manufacturing a semiconductor device of the present invention includes a step of manufacturing the Group 13 metal nitride crystal of the present invention. As a result, according to the present invention, a semiconductor device capable of supporting high frequencies can be manufactured, which has a great industrial advantage.

Below, the manufacturing method of the group 13 metal nitride crystal of this invention and the manufacturing method of the semiconductor device using the manufacturing method are demonstrated in detail. The description of the constituent elements described below may be made based on representative examples of embodiments of the present invention, but the present invention is not limited to such embodiments.
In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value. In addition, in the present specification, the “substrate surface” includes the surface of a substrate such as sapphire, SiC, ZnO, etc., as well as the surface of the formed group 13 metal nitride crystal. The “reaction field” means a liquid phase (A) containing a metal element belonging to Group 13 and a liquid phase (b1) obtained by dissolving a nitride containing a metal element other than Group 13 in a molten salt. This refers to the vicinity of the interface between the phase (B) of either the solid phase (b2) or the liquid phase (b3) containing a composite nitride containing a metal element other than Group 13 and a metal element other than Group 13. In the reaction field, the reaction proceeds as components of each phase diffuse into each other in the other phases. The liquid phase (b3) may be formed by dissolving a part of the solid phase (b2).

[Method for producing Group 13 metal nitride crystal]
The production method of the present invention includes a liquid phase (A) containing a Group 13 metal element and a liquid phase (b1) obtained by dissolving a nitride containing a metal element other than Group 13 in a molten salt or a Group 13 metal element. Group 13 which produces | generates reaction with the phase (B) of either the solid phase (b2) or liquid phase (b3) containing the composite nitride containing metal elements and metal elements other than Group 13 by this reaction A group 13 metal nitride crystal is grown by advancing while removing a by-product containing a metal element other than a metal from the reaction field.

  The liquid phase (A) containing a Group 13 metal element is preferably a liquid Group 13 metal alloy phase. The Group 13 metal alloy used in the production method of the present invention comprises a Group 13 metal element and a metal element other than Group 13. Preferred examples of the Group 13 metal include Ga, Al, In, GaAl, and GaIn. In addition, examples of the metal element other than the group 13 include Li, Na, Ca, and Mg, and among them, Li and Ca can be cited as preferable elements. Specific examples of preferable Group 13 metal alloys include Ga-Li alloys and Ga-Ca alloys.

The nitride used for the phase (B) in the production method of the present invention becomes a nitrogen source when growing a Group 13 metal nitride crystal. This nitride is a nitride of a metal element other than Group 13 or a composite nitride of the Group 13 metal and a metal element other than Group 13. Preferred nitrides include Li ₃ N, Ca ₃ N ₂ , GaLi ₃ N ₂ , Ca ₃ Ga ₂ N _{4 and the} like. These can be used by dissolving in a molten salt or a Group 13 metal.

In the present invention, a liquid phase containing a nitride can be reacted with a liquid phase that is the above Group 13 metal or an alloy phase thereof. In this case, even when a Group 13 metal simple substance is used as a reactant, a Group 13 metal alloy phase is formed by the progress of the reaction. The liquid phase containing the nitride is not particularly limited as long as it reacts with the Group 13 metal alloy, but is obtained by dissolving the nitride in a molten salt that is an ionic melt, or a Group 13 metal. A dissolved liquid phase is preferred. In particular, it is preferable to use a molten salt or a Group 13 metal saturated with nitride. Specifically, an excess of Li ₃ N is mixed with an alkali halide molten salt, and solid Li _{3 is} used to maintain saturation solubility. An example in which N coexists can be exemplified. If such a liquid phase having a low surface tension is used, it can easily enter the interface between the Group 13 metal nitride crystal and the Group 13 metal alloy.

In the present invention, the nitride is directly brought into contact with the Group 13 metal to form a liquid phase in which the nitride is dissolved in the vicinity of the interface of the Group 13 metal, and is reacted with the internal Group 13 metal alloy phase. be able to. Further, when the nitride is dissolved in the Group 13 metal, when the nitride is a simple Li ₃ N or Ca ₃ N ₂ , GaLi ₃ N ₂ , since Ca ₃ Ga composite nitride such as ₂ N ₄ is considered to be generated, as the nitriding source of the reaction, it is also desirable to the first _{GaLi 3 N 2, Ca 3 Ga} 2 N composite nitride such as ₄ way It is. In addition, these nitrides do not have to be chemically synthesized crystalline and deviate from the stoichiometric composition produced by reactive sputtering on a glassy substrate such as a sapphire substrate or quartz. A mixed nitride film may be used. When the nitride thin film produced by such a dry process is kept in contact with the Group 13 metal, the nitride gradually dissolves from the nitride thin film to the Group 13 metal, and a diffusion-dominated nitride dissolution phase is formed near the interface. Is particularly preferable. Further, the elements of the alloy components discharged into the Group 13 metal alloy by the reaction, for example, Li, Ca, etc., are generally often less dense than the Group 13 metal, and the Group 13 metal is promptly released from the reaction field. In order to diffuse into the alloy, it is desirable to react at the bottom of the Group 13 metal alloy and be removed from the reaction field due to density differences.

When carrying out the present invention using a molten salt, the type of the molten salt used is not particularly limited as long as it does not inhibit the progress of the reaction between the Group 13 metal and the nitrogen ion source. Examples thereof include salts, nitrates, and sulfides. Among these, it is preferable to use a halide because it is stable and the solubility of nitride is high. Further, the molten salt is a salt containing an alkali metal and / or an alkaline earth metal, and more preferably a compound that is used for a reaction for generating a nitrogen ion source.
From such a viewpoint, the molten salt is preferably an alkali metal salt such as Li, Na, or K and / or an alkaline earth metal salt such as Mg, Ca, or Sr, and more preferably an alkali metal salt. In particular, a Li salt is preferable. Further, the molten salt is preferably a metal halide such as LiCl, KCl, NaCl, CaCl ₂ , BaCl ₂ , CsCl, LiBr, KBr, CsBr, and any of LiCl, KCl, NaCl, CsCl and mixed salts thereof. More preferably.

  When impurities such as water are contained in the molten salt, it is desirable to purify the molten salt in advance by blowing a reactive gas. Examples of the reactive gas include hydrogen chloride, hydrogen iodide, hydrogen bromide, ammonium chloride, ammonium bromide, ammonium iodide, chlorine, bromine, iodine and the like. In particular, it is preferable to use hydrogen chloride.

  In the production method of the present invention, a liquid phase containing nitride is brought into contact with the above Group 13 metal or an alloy phase thereof for reaction. At this time, it is preferable to use a Group 13 metal nitride crystal or a substrate as a seed crystal for crystal growth. The shape of the seed crystal is not particularly limited, and may be a flat plate shape or a rod shape. Further, it may be a seed crystal for homoepitaxial growth or a seed crystal for heteroepitaxial growth. Specifically, a seed crystal of a group 13 metal nitride such as GaN, InGaN, or AlGaN which has been vapor-phase grown can be used. In addition, metal oxides such as sapphire, silica, ZnO, and BeO, silicon-containing materials such as SiC and Si, and materials used as a substrate in vapor phase growth of GaAs and the like can be given. The seed crystal and substrate material are preferably selected as close as possible to the lattice constant of the Group 13 metal nitride crystal grown in the present invention. When a rod-shaped seed crystal is used, a bulk crystal is produced by first growing in the seed crystal portion, then performing crystal growth mainly in the horizontal direction, and then performing crystal growth in the vertical direction. You can also. When the crystal growth in the horizontal direction is performed, it is preferable to control the group 13 alloy composition distribution in the horizontal direction so that the crystal growth stops at an appropriate portion up to the side wall of the container.

In the present invention, the reaction when a Ga—Li alloy is used as the Group 13 metal alloy and lithium nitride or gallium lithium nitride is used as the nitrogen source is basically represented by the following equation or the like.
Ga + Li ₃ N = GaN + 3Li (1)
_{Ga + GaLi 3 N 2 = 2GaN} + 3Li (1) '
It is conventionally known that a GaN crystal is produced by melting GaN powder or GaN microcrystal together with Ga metal, lithium metal, lithium nitride or the like with a crucible (Chinese Patent Publication No. 1288079A). However, in the prior art, Ga metal, Li metal, lithium nitride, GaLi nitride, etc. are considered as a dissolving agent for dissolving GaN powder or GaN microcrystals, so they are mixed in the same crucible. It was kept. At this time, molten salt is not used in the reaction field. The size of the crystals thus obtained was at most 5 to 10 mm, and only thin plate crystals were obtained. Further, it is very difficult to elucidate the reason why only small crystals are obtained in a system in which the reactant and the product are mixed together and they are dissolved in each other.

Li metal produced by the reaction formulas (1) and (1) ′ is dissolved in Ga metal which is one of the reaction sources, but as the reaction proceeds, the Li metal concentration in the Ga metal increases, and the formula (1) , (1) 'reaction reaches equilibrium and stops. For this reason, the inventors of the present invention considered that the growth of crystals is slow and that only a small crystal can be obtained by the conventional technique, and developed the present invention having means for solving this problem.
In the present invention, Ga metal as a reaction source and Li ₃ N and GaLi ₃ N ₂ dissolved in the molten salt or Ga metal constitute separate liquid phases, respectively, and the reaction formula (1) , (1) ′, Li metal is dissolved in Ga metal which is one of the reaction sources. The Li metal concentration in the Ga metal increases with the progress of the reaction, but the concentration of the Li metal that forms an alloy with the Ga metal is controlled by some means. That is, by allowing the reaction system side Ga alloy to absorb the Li concentration on the production system side, the reactions of the reaction formulas (1) and (1) ′ can always proceed to the right side. When the reaction portion with the nitride is directed to the lower part of the Ga metal, the Li metal produced by the reaction has a density lower than that of the Ga metal, and therefore moves in the Ga-Li alloy in the upper direction, and the Li concentration is higher in the upper part. Get higher. That is, it moves in the upper direction in the Ga—Li alloy near the reaction part, and the Li concentration becomes higher at the upper part. That is, the Li concentration in the Ga—Li alloy near the reaction part can be controlled naturally. Thus, the Li having a high concentration at the top is removed by some method. As one method, the reaction of the formulas (1) and (1) ′ is continuously performed by removing the Ga metal alloy phase by an electrochemical method or the like so that the composition of the Ga metal alloy phase is within a certain range. Can be made.

  When a molten salt containing a nitrogen source is floated on a low melting point Group 13 metal liquid such as Ga and a seed crystal is placed on the surface of the Ga metal, the molten salt enters between the seed crystal surface and the liquid Ga metal. A thin film-like nitride dissolved phase can be formed to grow a crystal. As the crystal grows, the alkali metal element (Li), which is a reaction product, dissolves in the liquid Ga metal to form an alloy. At this time, as a method of removing the alkali metal element (Li), for example, Ga or Al which is dissolved in the form of Li ions in the molten salt by anodic dissolution of the liquid Ga alloy and alloyed with Li on the cathode side in the bath A method of using a metal such as a cathode as a cathode electrode can be employed, whereby Li can be easily recovered. In addition to the electrochemical method, there is also a method of transferring the Group 13 metal alloy to another reaction vessel, adjusting the composition there, and then returning it to the crystal growth reactor. There is also a method in which a Group 13 metal alloy having an increased Li metal concentration is led to another container, where a halogen or halide gas is reacted to form Li halide. The produced Li halide is easily dissolved in the molten salt.

By these methods, in the present invention, the reactions of the formulas (1) and (1) ′ can be continuously performed with the composition of the Ga metal alloy phase close to the reaction field within a certain range. The term “within a certain range” means that the fluctuation range of the Ga content in the Ga metal alloy phase is within ± 25 atomic%, more preferably within ± 10 atomic%, more preferably within ± 5 atomic%. More preferably.
Thus, by controlling the composition of the group 13 metal alloy phase within a certain range in the vicinity of the growth interface of the group 13 nitride crystal, a thick or bulk group 13 metal nitride crystal is grown. It becomes possible to make it. The quality of the Group 13 nitride crystals obtained by the present invention also depends on the reaction speed controlled in this way. Since the reaction rate varies depending on the concentration of Li metal that forms an alloy with Ga metal, it is preferable to select an optimum composition for the alloy.

  In the present invention, the reaction between the Group 13 metal and the nitrogen source is carried out at the liquid phase interface or the substrate surface. The reaction temperature is usually 200 to 1000 ° C., preferably 400 to 850 ° C., more preferably. Is 600-800 degreeC.

In the present invention, if a nitrogen source is dissolved in a molten salt, it can be used at a temperature lower than the melting point of the nitrogen source compound. Further, if an excessive nitrogen source is added, the concentration in the molten salt becomes saturated solubility, and the activities of Li ₃ N and GaLi ₃ N _{2 in} the formulas (1) and (1) ′ are preferably 1. Also, the molten salt and the Group 13 metal alloy are preferable because they exist as completely separate phases, the reaction at their interface is uniform, and the rate of the reaction can be accelerated. In the case where the nitride-dissolved phase is formed in the Group 13 metal, the nitride solid is brought into contact with the Group 13 metal, and a liquid phase in which the nitride is dissolved is formed at the interface by dissolution from the contact portion and natural diffusion. It is preferable that the shape of this phase is not disturbed by convection. When a substance other than the Group 13 metal is used for the purpose of doping, the object can be achieved within the production process of the present invention by adding to a molten salt or a Group 13 metal alloy.

Since powders such as Li ₃ N used as a nitrogen source are hygroscopic and easily contain moisture etc. when used as a raw material, Li ₃ N is preliminarily added to the crucible from the viewpoint of preventing the entry of impurities such as moisture from outside the reaction system. It is preferable to use a material that has been solidified after being melted by heating.
GaLi ₃ N ₂ can be produced by sintering GaN and Li ₃ N at about 800 ° C. or by heat-treating a Ga—Li alloy at 600 to 800 ° C. in a nitrogen atmosphere. GaLi ₃ N ₂ can be used alone or as a mixture with Li nitride. By doing so, it can be easily melted into the molten salt or Ga alloy. Also, Li metal, the Gali alloy as a target, perform reactive sputtering using a nitrogen plasma, Li-N, make a mixed composition film of Gali-N, which Li ₃ N, substitution of Gali ₃ N ₂ It can also be. In this case, not only is it convenient for producing a thin film-like crystal, but there is an advantage that a material system that is difficult to synthesize chemically, for example, a material such as Ga-Na composite nitride, can be produced.

  The Group 13 metal nitride crystal obtained by the production method of the present invention is a single metal nitride (for example, GaN, AlN, InN) or a nitride of a synthetic composition (for example, GaInN, GaAlN), particularly GaN. It can be suitably used as a crystal production method. Crystal growth of the Group 13 metal nitride is preferably performed using a seed crystal or by growing a crystal on a substrate.

  Next, the manufacturing method of the present invention will be described more specifically with reference to the drawings. 1, FIG. 2, FIG. 3, FIG. 13 and FIG. 14 are diagrams showing a configuration example of a manufacturing apparatus for growing a group 13 metal nitride crystal used in carrying out the present invention. 5 and 15 are diagrams showing the apparatus used in the embodiment of the present invention. FIG. 6 is a schematic explanatory diagram of the apparatus for purifying molten salt. It is preferable that the molten salt used for crystal growth is purified (mainly dehydrated) in advance by this apparatus.

  Molten salts such as chlorides generally contain a large amount of moisture because of their high hygroscopicity. When a molten salt containing water is used in carrying out the present invention, it is not preferable because an oxide of a Group 13 metal is formed in the reaction vessel and the reaction vessel is easily corroded. Therefore, it is preferable to remove impurities such as water in advance by using a sample-sealed pretreatment apparatus as shown in FIG. 6 (molten salt, basics of thermal technology, see p266 issued by Agne Technical Center Co., Ltd.). . When purifying using the apparatus shown in FIG. 6, first, the metal salt to be purified is placed in the purification container 25, and the inside of the purification container 25 is evacuated from the gas outlet 23 under vacuum or for the salt purification apparatus. The temperature of the electric furnace 29 is increased, and the metal salt is melted by switching to an inert gas atmosphere such as argon gas or a reactive gas atmosphere such as hydrogen chloride gas. Thereafter, a reactive gas such as hydrogen chloride gas is blown into the molten metal salt from the gas introduction pipe 24 through the porous filter 26 for about 1 hour or longer to perform bubbling. After bubbling is completed, the molten salt is transferred to the sample reservoir 27 by depressurizing the gas inlet tube 24 side and applying pressure using an inert gas from the gas outlet 23 side as necessary. After cooling, the purified sample is vacuum-sealed and stored by evacuating and sealing the upper portion of the sample reservoir 27. In addition, when heavy metals etc. which cannot be removed by the above method are contained in the molten salt, it is preferable to further purify the salt by the zone melt method.

Next, the step of growing a Group 13 metal nitride crystal according to the production method of the present invention will be specifically described. Here, a Ga—Li alloy as a Group 13 metal alloy composed of a Group 13 metal element and a metal element other than Group 13, a LiCl—KCl molten salt purified by the apparatus of FIG. 6 as the molten salt, A case where Li ₃ N or GaLi ₃ N ₂ is used as a nitride of a metal element other than a group metal will be described as an example. The following description can also be applied when other materials are selected.

FIG. 1 is a schematic view of a typical manufacturing apparatus used in carrying out the present invention. First, Ga metal or Ga-Li alloy 4 is placed in a magnesium oxide reaction vessel 15, and a molten salt 7 having a low melting point such as purified LiCl or binary eutectic salt LiCl-KCl is placed thereon. In this molten salt, Li ₃ N and GaLi ₃ N ₂ which are nitrogen sources are dissolved to saturation solubility. When the temperature of the molten salt is lower than the melting point of Li ₃ N (813 ° C.) and the melting point of GaLi ₃ N ₂ , saturation solubility can be maintained by floating the solid Li ₃ N mass 8 in the molten salt 7. In the case of GaLi ₃ N ₂ , the interface between the molten salt 7 and the Ga metal 5 is maintained from the density. The Li ₃ N lump used here can be prepared by dissolving and solidifying Li ₃ N in another reaction vessel and then crushing it. In the case of a nitride having a small density such as Li ₃ N, if the density of the molten salt is much larger than the density of the Li ₃ N mass (about 1.4 g / cm ³ ), the dissolved Li ₃ N is Since it is distributed only above the molten salt and the Li ₃ N concentration near the interface with the Ga alloy is difficult to increase, in the present invention, a molten salt having a slightly higher density than Li ₃ N can be selected and used. preferable. Usually, a molten salt having a density of about 1.6 to 2.2 g / cm ³ is used. If the concentration of Li ₃ N in the molten salt varies, the bath may be gently stirred.

  In the figure, 1 is a growing GaN crystal. The molten salt penetrates into the interface between the GaN crystal 1 and the Ga alloy 4 to form a thin-film nitride dissolved phase 14, and forms a GaN crystal according to the reaction formula shown in the Ga and the above equation (1). Li metal as a by-product forms an alloy with Ga metal.

The standard free energy ΔG ₀ in equation (1) is 42.5 kJ / mol (900 K), and the reaction in the standard state is biased to the left side, but when the Li concentration in the Ga alloy is low, the reaction is on the right side. Proceed to This data is quoted from Thermochemical Data of Pure Substances: 2nd Edition (1993) Publisher: VCH Verlagsgesellschaft mbH, D6940 Weinheim (Federal Republic of Germany). In the reaction formula (1), the Li activity a _Li in an equilibrium state at 900 K is about 0.15. This is calculated as ΔG = 0 (equilibrium condition) in equation (2).
△ G = △ G ₀ + RT ln Kp (2)
From Kp = a _Li3 a _GaN / a _Li3N a _Ga , a _Li = exp (− △ G ₀ / 3RT)

Ga-Li binary phase diagram (Landolt-Bornstein "Numerical Data and Functional Relationships in Science and Technology" New Series (Editor in Chief: W. Marienssen)
As seen in Group IV: Physical Chemistry, Volume 5 “Phase Equilibria, Crystallographic and Thermodynamic Data of Binary Alloys”, this system produces a high melting point intermetallic compound at a composition ratio of 1: 1. It is considered that the activity coefficient of Li on the high concentration side (Li low concentration side) is considerably small. In fact, in the activity diagram described together with the above phase diagram, the activity of Li is about 0.15 (activity coefficient is about 0.3) at 50 atomic% -Li. It is considered that the activity coefficient is further lowered when Li is at a low concentration, and is on the order of 0.01 below 10 atomic% -Li. That is, the activity of Li decreases to a value that is much less than 10 ⁻³ . Accordingly, the reaction of formula (1) proceeds very rapidly at an extremely low Li activity at the beginning of the reaction, but the reaction does not proceed rapidly as the Li concentration in the Ga alloy increases with the reaction, and 50 atoms It stops when it approaches the composition of% -Li. Thus, the Li concentration in the Ga alloy varies greatly depending on the degree of progress of the reaction, and the reaction rate also varies greatly accordingly. In order to grow a crystal stably, it is preferable to avoid such instability of the reaction rate.

Therefore, in the present invention, it is preferable to extract Li generated in the Ga alloy as the reaction proceeds and to control the Li concentration to a constant value. For example, if the apparatus shown in FIGS. 1 and 2 is used, the Li concentration can be controlled to a constant value. In the apparatus of FIG. 1, when the crystal 1 is rotated as indicated by the arrow in the figure, the Ga alloy 4 under the crystal is moved outward by centrifugal force, so that the Ga alloy 4 in the container flows as indicated by the arrow. At this time, if the partition plate 6 is installed in the container, the movement of the Ga alloy 4 in the vicinity of the inner wall of the container is slow in the upper part of the partition plate 6, and the concentration of the Li metal generated by the equation (1) To rise. As a result, in the vicinity of the inner wall of the container, the activity of Li is increased, and the equilibrium of the formula (1) is from the left, preventing excessive GaN from being formed at the interface between the molten salt 7 and the Ga alloy 4 and becoming crusted. be able to. Furthermore, since the carbon electrode 9 is inserted into the Ga alloy near the inner wall of the container, the alloy is anodic dissolved. Since Li is easier to dissolve in terms of potential than Ga, Li is easily anodicly dissolved and dissolved as ions in the electrolytic bath 7 to produce metallic Li at the cathode electrode 10. In FIG. 1, nitrogen gas 12 is reacted with the produced metal Li to produce Li ₃ N in a bath and used again as a nitrogen source. In FIG. 2, liquid Ga or solid or liquid Al is used as the cathode electrode 16, and the deposited metal Li is alloyed with Ga or Al to immobilize the metal Li. On the other hand, the thin film nitride dissolved phase 14 formed by the molten salt entering the interface between the GaN crystal 1 and the Ga alloy 4 decreases the nitrogen source concentration as the reaction proceeds. It is necessary to supply the source. When the crystal growth is slow, there is no problem with the supply of the nitrogen source, but when the growth rate is fast, the crystal 1 may be moved up and down slightly during the growth so that a new electrolytic bath is taken into the interface. preferable. In this way, GaN crystals can be continuously grown.

  In addition, the method of controlling the density | concentration of the produced | generated metal Li is not limited to the electrochemical method shown in FIG. For example, it is possible to remove the metal Li in the Ga alloy by taking out a Ga alloy having a high concentration of metal Li outside the container and blowing a halogen gas such as hydrogen chloride gas or chlorine gas. is there.

FIG. 3 is another type of crystal growth apparatus suitable for practicing the present invention. A Ga-Li alloy 4 is placed in a magnesium oxide reaction vessel 15, and a molten salt 7 having a low melting point such as purified LiCl or binary eutectic salt LiCl-KCl is placed thereon. Further, in the molten salt, Li ₃ N and GaLi ₃ N ₂ which are nitrogen sources are dissolved to saturation solubility. Further, a plurality of disk-like substrates 19 are placed on a substrate holder 21 having a rotation axis substantially parallel to the interface 20 between the two liquid phases, and the plate-like substrate is rotated to rotate the molten salt 7 and the alloy 4. Are in contact with each other. By doing so, crystal growth occurs when the substrate passes through the two-liquid phase interface 20 and / or when the molten salt 7 attached to the substrate surface enters the alloy by rotation of the substrate. In FIG. 3, the anode electrode 9 and the cathode electrode 16 are used for controlling the concentration of metal Li in the alloy 4. That is, when the Ga—Li alloy 4 is used as an anode, Li is preferentially dissolved in the anode and dissolved into the electrolytic bath 7 as ions. The Li ions are deposited as metal Li at the cathode 16 and alloyed. Therefore, the composition of the Ga—Li alloy can be controlled electrochemically.

  In order to anodically dissolve Li metal from the Ga alloy between the substrates as Li ions in the molten salt, it is effective to dispose the cathode 16 between the substrates, and the substrate usually supports the outer periphery. Therefore, the cathode disposed between the substrates is preferably configured to move in synchronization with the rotational movement so that the cathode does not collide with the substrate holder 21 as the substrate rotates.

As the substrate 19, for example, sapphire, SiC or the like can be used, but a plate-like GaN crystal is preferably used. Crystals are preferably grown on both sides of a plate-like GaN crystal to form several wafers, and one of them is used as a substrate for the next crystal growth. It is preferable that Li ₃ N and GaLi ₃ N ₂ that are nitrogen sources are appropriately supplied from the reservoir 30 as the crystal grows.

FIGS. 13 and 14 show an apparatus for producing a liquid phase in which a nitride is dissolved in a Ga—Li alloy. GaLi ₃ separately produced using a physical process such as chemical or reactive sputtering. A nitride 8 such as N ₂ is fixed in a vessel 31 such as magnesia or tungsten, and a liquid phase 32 in which nitride is dissolved in liquid Ga metal is formed so as to be in direct contact with the Ga alloy. GaN produced according to the formula (1) ′ grows epitaxially on the substrate 2, and Li is taken into the alloy phase 4. At this time, the substrate support rod 3 may be slowly rotated in order to promote crystal growth. In addition, since the alloy phase 4 becomes a Ga—Li alloy when the reaction starts, it may be a Ga metal alone at first. At this time, when the Li concentration increases and the density decreases due to the reaction, the alloy portion with a high Li concentration near the reaction field moves naturally upward, so if the amount of Ga alloy is sufficiently large, the reaction continues without stopping. In addition, since the Li concentration is increased in the upper portion 5 of the Ga alloy, a thin GaN crystal or a small bulk crystal can be manufactured without artificially controlling the Li concentration. In order to greatly grow GaN as a thick film or bulk, for example, the molten salt 7 shown in FIG. 13 is placed on the upper part of the alloy 4, Li is anodically dissolved and moved to the cathode 16, and the Li concentration in the alloy 4 is increased. Control is sufficient. In order to produce solid GaLi ₃ N ₂ , GaN powder and Li ₃ N powder may be sintered by adding a suitable flux, for example, a small amount of alkali halide (LiCl or the like). Further, the first time to prepare a Gali alloy, which is under a nitrogen atmosphere 600 to 700 ° C., can make GaLi ₃ N _2. A method of crushing this and adding a small amount of alkali halide to sinter is also a simple and effective method.

FIG. 14 shows a case where a thin film 35 made of a mixture such as Ga—Li—N is formed on a substrate 34 made of quartz, sapphire, GaN or the like by using a dry process such as sputtering and is brought into contact with the Ga metal 4. Then, a nitride dissolved phase 34 is formed, and a GaN crystal is grown on the substrate 34. In the figure, reference numeral 36 denotes a partition plate for preventing the reaction between the nitride thin film 35 and the Ga metal 4 at portions other than the crystal growth portion, and tungsten or the like is used as the material.
The atmosphere 17 in the reaction vessel may be a nitrogen atmosphere, but if it is a nitrogen atmosphere, it reacts with Li at the interface with the Ga—Li alloy to form a nitride, which reacts with Ga to form GaN with poor crystallinity. In the present invention, the atmosphere is preferably an inert gas such as Ar because it has an adverse effect that it is easy to make.

  The dissociation pressure of the generated GaN is 1 atmosphere at 650 ° C. when calculated from the free energy of generation, and it is generally said that decomposition starts when the temperature reaches 650 ° C. or higher at atmospheric pressure. However, according to the present invention, even at an atmospheric pressure of 800 ° C., GaN does not decompose into Ga metal and nitrogen gas in the alloy or molten salt. Further, as apparent from the equation (1), since dissolution and precipitation of GaN crystals can be controlled by the Li concentration in the Ga alloy, remelting and recrystallization can be repeated at the solid-liquid interface of crystal growth. As a result, since the quality of the crystal can be improved, the present invention is extremely advantageous.

[Method for Manufacturing Semiconductor Device]
The manufacturing method of this invention can be used for the process of manufacturing the group 13 metal nitride crystal in the manufacturing method of a semiconductor device. The raw materials, conditions, and apparatuses used in general semiconductor device manufacturing methods can be applied as they are for the raw materials, manufacturing conditions, and apparatuses in other processes.

  The features of the present invention will be described more specifically with reference to the following 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.

Example 1
Using the apparatus shown in FIG. 5, GaN crystal growth was performed at the interface between the molten salt and the Ga—Li alloy without using a GaN seed crystal or substrate. About 4.6 g of molten salt, about 0.6 g of Li ₃ N, and about 7 g of a Ga—Li alloy (about 3 atomic% of Li) are put in a magnesium oxide reaction vessel (crucible) 15 in a nitrogen atmosphere (atmospheric pressure). Dissolved. Due to the density, as shown in FIG. 5, the molten salt 7 is separated into two phases, that is, the upper phase portion of the molten salt 7 and the lower phase portion of the Ga—Li alloy 4, and the block-like Li ₃ N8 floats in the molten salt bath. Dissolved to saturation concentration. Li ₃ N was previously melted in a nitrogen atmosphere with another crucible, solidified, and then crushed into a block shape. As the molten salt, a binary salt (60/40 mol%) of LiCl—KCl having a melting point of about 370 ° C. was used. Each salt of the LiCl-KCl binary system was purified by itself using the apparatus shown in FIG. 6, and the sample was weighed and dissolved under vacuum to obtain a mixed salt. The metal Li deposited by the reaction of formula (1) formed an alloy with Ga metal, and the Li concentration increased with the growth of GaN. In order to keep this rising Li concentration constant, the electrode 9 was put in a Ga—Li alloy to make an anode, and Li in the alloy was anodic dissolved as ions in the molten salt 7. On the other hand, in the molten salt 7, a cathode 16 containing a Ga metal liquid was placed, Li ions were precipitated, and a Ga—Li alloy was produced, thereby controlling the composition of the lower phase Ga—Li alloy.

  The internal temperature of the reaction vessel 15 was maintained at about 780 ° C., and an electrolysis current of 40 mA was passed for 8 hours (the amount of electricity was about 1,000 coulombs). After the experiment was completed, the sample was allowed to stand and cooled to room temperature, cooled with liquid nitrogen to completely solidify the Ga alloy, the metal components were separated, and the contents of the crucible were eluted with concentrated hydrochloric acid. According to the ICP-AES standard addition method (Li), the Li concentration of the Ga-Li alloy 4 is 3.2 atomic% before the experiment and 4.3 atomic% after the experiment. It is thought that it was suppressed to about 1 atomic%. In addition, since the intermetallic compound having a high melting point of the Ga—Li alloy is separated and separated into two phases during the cooling process, the analysis was performed by dissolving all of them uniformly. FIG. 7 shows a photomicrograph of the transparent crystalline powder (diameter 0.5 to 1 mm) thus taken out. As can be seen from FIG. 7, the crystal grows in a vortex and has a flat surface on the C plane, so it is considered that the crystal has grown at the interface between the alloy 4 and the electrolytic bath 7. Although the generated GaN is slightly larger than the density of the Ga—Li alloy, it is considered that a considerable portion stops at the interface between the alloy 4 and the electrolytic bath 7 due to the surface tension when left standing. FIG. 8 shows X-ray diffraction data. It is characteristic that the diffraction peak from (002) is large. From this, it can be seen that the C plane is developed and the crystallinity is high. Table 1 shows the half widths of typical diffraction peaks of the X-ray diffraction data of the obtained crystals.

(Example 2)
Crystal growth was performed under the same conditions as in Example 1 except that the current was set to 20 mA and the energization time was extended to 16 hours (the amount of electricity was approximately 1000 coulombs which was almost the same as in Example 1). Similarly to Example 1, micrographs and SEM photographs of the obtained transparent powder (diameter 0.5-2 mm) are shown in FIGS. 9 and 10, respectively. It is almost the same as Example 1 except that the crystal is enlarged in a plane, and the Li concentration of the Ga—Li alloy is 2.9 atomic% before the experiment and 4.8 atomic% after the experiment. there were.
Since the X-ray diffraction data is exactly the same as in Example 1, the illustration is omitted. Note that the photographs shown in FIG. 9 and FIG. 10 are taken by selecting a portion having a similar shape on the surface of the crystal grain, but it is not the same place.

(Example 3)
Crystal growth was performed under the same conditions as in Example 1 except that the apparatus of FIG. 4 without electrodes was used and electrolysis was not performed. The duration of the experiment is 8 hours. A micrograph of the obtained white powder (diameter less than 0.5 mm) is shown in FIG. The Li concentration of the Ga—Li alloy 4 is 3.1 atomic% before the experiment and 13.7 atomic% after the experiment, which is significantly higher than those of Examples 1 and 2 in which electrolysis was performed. The Li concentration was increased, and the size of the obtained powder crystals was small. The diffraction peak intensity ratio of the X-ray diffraction data is almost the same as in Examples 1 and 2, but the half-value width of each peak is slightly wider than in Examples 1 and 2, as shown in Table 1. It seems that the crystallinity is slightly deteriorated.

Example 4
Crystal growth was performed under the same conditions as in Example 3 except that the experiment time was extended to 16 hours. A photomicrograph of the resulting white powder crystal (diameter less than 0.5 mm) is shown in FIG. Despite extending the experiment time, the size of the crystal is not so large compared to the crystal of Example 3. Further, the Li concentration of the Ga—Li alloy 4 was 3.3 atomic% before the experiment and 14.1 atomic% after the experiment, which is significantly higher than that of Examples 1 and 2 in which electrolysis was performed. The Li concentration of the Li alloy 4 was increased. The full width at half maximum of the diffraction peak of the X-ray diffraction data is as shown in Table 1, which is slightly wider than that of Examples 1 and 2.

(Example 5)
Crystal growth was performed under the same conditions as in Example 3 except that about 20% by weight of Mg was further added to the Ga—Li alloy. The obtained white powder (diameter less than 0.5 mm) is very similar to the photomicrograph of FIG. 3 (FIG. 11). Impurities in the crystals are analyzed by inductively coupled plasma emission spectroscopy, mass spectrometry ICP-AES, QMS. As a result of measurement and analysis, they were respectively Li0.0028 wt% and Mg 0.65 wt%. The analysis results in Example 3 were Li 0.0034 wt% and Mg 0.0055 wt%, and it was found that Mg was doped into the crystal by adding Mg to the alloy.
In addition, also in the crystal produced in Example 3, it was presumed that MgO used in the crucible was caused by a trace amount of Mg.

Example 6
About 2 g of gallium nitride and lithium nitride reagent (Mitsuwa Chemical Co., Ltd.) mixed in a mortar and having a molar ratio of about 1: 1 was put in a magnesia crucible and baked at 800 ° C. for about 6 hours in a nitrogen atmosphere. The sample had a mixed color of gray and magenta before firing, but changed to whitish gray after firing. FIG. 16 shows X-ray data of this sample, and it can be seen that GaLi ₃ N ₂ was generated.
The same experiment as in Example 3 was performed except that GaLi ₃ N ₂ synthesized in this way was used instead of Li ₃ N, the experimental temperature was 740 ° C. under a nitrogen atmosphere, and LiCl was used as the molten salt. The molten salt used was 4.3 g of LiCl, 10.5 g of a GaLi (Li 3.2 atomic%) alloy, and 0.60 g of GaLi ₃ N ₂ . It should be noted that the temperature of the experiment is lower than that of Example 3 because decomposition starts before GaLi ₃ N ₂ dissolves in the molten salt at a high temperature, and Li as a by-product in the reaction is promptly changed to Ga metal. The amount was increased to about 10 g so as to form an alloy. From the relationship of density, it is considered that GaLi ₃ N ₂ put in the crucible exists near the interface between the salt and Ga metal, unlike Li ₃ N, but in the end, most of it dissolves in the bath, It is thought to react with Ga metal and generate GaN. Further, the Li concentration of the Ga—Li alloy 4 was 3.2 atomic% before the experiment and 8.4 atomic% after the experiment. Compared with Example 3 using Li ₃ N, the rise of Li in the alloy is small, but as a result of the reaction of formula (1) ′, the Li concentration in the Ga alloy is increased and GaN is generated. It is considered a thing. FIG. 17 shows an optical micrograph of the GaN powder obtained in this experiment, and Table 1 shows the full width at half maximum of the X-ray data. Compared to Example 3 using Li ₃ N, the crystallinity was rather good.

(Example 7)
An experiment similar to that in Example 6 was performed except that pure Ga was used instead of the Ga alloy and the nitrogen atmosphere was changed to an argon atmosphere. The molten salt used was LiCl 4.2 g, Ga metal 11.1 g, and GaLi ₃ N ₂ 0.62 g. The Li concentration of the Ga—Li alloy 4 was 3.2 atomic% before the experiment, and the Li concentration in Ga after the experiment was 6.5 atomic%. An optical micrograph of the GaN powder obtained in this experiment is shown in FIG. 18, and the half width of the X-ray data is shown in Table 1. Even in an inert atmosphere other than nitrogen, a large number of crystals having a complex growth on the hexagonal plate-like crystal surface were observed, and good crystals similar to those in Example 6 were obtained from the X-ray data. .

(Example 8)
Experiments were performed using the apparatus shown in FIG. 15 using GaLi ₃ N ₂ produced in Example 6. A GaLi ₃ N ₂ grain 8 is placed on the bottom of a magnesia crucible 15 so that it does not float when the Ga-Li alloy 4 is put on it with a tungsten mesh 33. The substrate surface 1 with the GaN film was placed face down on a tungsten net. In this way, it was allowed to stand at 720 ° C. for 8 hours. GaLi ₃ N ₂ is gradually dissolved in the Ga-Li alloy 4 to form a Ga metal liquid phase 32 in which GaLi ₃ N ₂ is dissolved in the vicinity of the upper portion of the tungsten net 33, and the Ga alloy phase 4 ( 1) The reaction of the formula 'occurs. In this way, GaN grows on the substrate 1. 19a and 19b are SEM photographs of the crystal thus grown. Although the surface of the sample was analyzed by EPMA, elements other than Ga and N were not observed and it was not a complete film, but in FIG. 19a, a hexagonal plate-like GaN crystal grew with the C-plane facing up. Depending on the location, although it is incomplete as shown in FIG. 19b, a thin film portion was also observed.

  The above examples show that good crystals can be obtained without seed crystals. Crystal growth is performed using the apparatus shown in FIGS. 1 to 3 while controlling the Li activity in the Ga—Li alloy, that is, the concentration within an optimal range, and using the group 13 metal nitride crystal or substrate as a seed crystal. If this is done, it is considered that a thick bulk crystal can be grown.

  According to the method for producing a Group 13 metal nitride crystal of the present invention, a Group 13 metal nitride crystal having a size sufficient to be easily applied to a semiconductor device can be produced using an inexpensive apparatus. . In particular, since it can be used for the manufacture of a semiconductor device capable of supporting frequencies, which has been considered difficult to manufacture, there is a great industrial advantage.

It is a schematic explanatory drawing which shows the suitable crystal growth apparatus (the 1) used by manufacture of the crystal | crystallization of the group 13 metal nitride of this invention. It is a schematic explanatory drawing which shows the suitable crystal growth apparatus (the 2) used by manufacture of the crystal | crystallization of the group 13 metal nitride of this invention. It is a schematic explanatory drawing which shows the suitable crystal growth apparatus (the 3) used by manufacture of the crystal | crystallization of the group 13 metal nitride of this invention. It is a schematic explanatory drawing which shows the crystal growth apparatus used in the Example. It is a schematic explanatory drawing which shows the crystal growth apparatus with an electrode used in the Example. It is a schematic explanatory drawing which shows one embodiment of the refiner | purifier of the molten salt used by this invention. 2 is an optical micrograph of a GaN crystal obtained in Example 1. 3 is X-ray diffraction data of the GaN crystal obtained in Example 1. FIG. 3 is an optical micrograph of a GaN crystal obtained in Example 2. 4 is a SEM photograph of the GaN crystal obtained in Example 2. 4 is an optical micrograph of a GaN crystal obtained in Example 3. 4 is an optical micrograph of a GaN crystal obtained in Example 4. It is a schematic explanatory drawing which shows the structural example of the manufacturing apparatus for Group 13 metal nitride crystal growth. It is a schematic explanatory drawing which shows the structural example of the manufacturing apparatus for Group 13 metal nitride crystal growth. It is a schematic explanatory drawing which shows the suitable crystal growth apparatus (the 4) used by manufacture of the crystal | crystallization of the group 13 metal nitride of this invention. 4 is an X-ray diffraction data of GaLi ₃ N ₂ crystal obtained in Example 6. FIG. 6 is an optical micrograph of a GaN crystal obtained in Example 6. 4 is an optical micrograph of a GaN crystal obtained in Example 7. 6 is a SEM photograph of the GaN crystal obtained in Example 8.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 GaN crystal 2 Substrate or GaN crystal 3 Substrate support rod 4 Ga-Li alloy 5 Ga metal alloy with high Li concentration 6 Partition plate 7 Molten salt containing nitrogen ion source 8 Li ₃ N block or GaLi ₃ N ₂ block 9 Anode electrode 10 cathode electrode 11 the gas inlet tube 12 nitrogen gas 13 solid Li ₃ N divider plate 14 nitride dissolved phase (molten salt film by dissolving a Li ₃ N)
15 Reaction vessel for magnesium oxide 16 Cathode electrode and metal for Li alloy (Ga metal)
17 Nitrogen gas or Ar atmosphere 18 Electric furnace 19 Substrate or grown crystal 20 Alloy-molten salt interface 21 Substrate or crystal holding and rotating mechanism 22 GaN crystal 23 Gas outlet 24 Gas inlet tube 25 Purification vessel 26 Porous filter 27 Sample reservoir 28 Hydrogen chloride gas 29 Electric furnace 30 for salt refining equipment Reservoir (solid Li ₃ N)
31 GaLi ₃ N ₂ solid container 32 Ga alloy liquid phase 33 in which GaLi ₃ N ₂ is dissolved Tungsten net 34 Sputter substrate 35 Ga-Li-N thin film 36 Tungsten partition plate

Claims (16)

A liquid phase (A) containing a metal element belonging to Group 13 of the periodic table and a liquid phase (b1) obtained by dissolving a nitride containing a metal element other than Group 13 of the periodic table in a molten salt or a metal belonging to Group 13 of the periodic table A periodic table in which a reaction between the element and the solid phase (b2) or the liquid phase (b3) containing the composite nitride containing a metal element other than Group 13 of the periodic table (B) is generated by the reaction. Periodic table Group 13 metal nitride crystals are grown by removing by-products containing metal elements other than Group 13 metals from the reaction field, and growing Manufacturing method. The method for producing a periodic table group 13 metal nitride crystal according to claim 1, wherein the by-product is removed from the reaction field by moving into the liquid phase (A). The method for producing a periodic table group 13 metal nitride crystal according to claim 1, wherein the liquid phase (A) can be alloyed with the by-product. The periodic table group 13 metal nitriding according to any one of claims 1 to 3, wherein the liquid phase (A) and the liquid phase (b1) are reacted while maintaining a separated state. Method for producing physical crystals. The liquid phase (A) and the liquid phase (b1) are reacted while alternately contacting each other, and the periodic table group 13 metal nitride crystal according to any one of claims 1 to 4 is used. Production method. The periodic table group 13 metal according to any one of claims 1 to 3, wherein the liquid phase (b3) is formed between the liquid phase (A) and the solid phase (b2). A method for producing a nitride crystal. The periodic table group 13 metal according to any one of claims 1 to 6, wherein the by-product is removed from the reaction field via the liquid phase (A) by an electrochemical reaction. A method for producing a nitride crystal. 8. The method for producing a periodic table group 13 metal nitride crystal according to claim 7, wherein in the cathode reaction of the electrochemical reaction, the by-product is reacted with nitrogen gas to form a nitride. 8. The method for producing a periodic table group 13 metal nitride crystal according to claim 7, wherein in the cathode reaction of the electrochemical reaction, the by-product is alloyed with a metal element contained in the cathode electrode. 7. The by-product is removed from the liquid phase (A) by reacting a halogen or halide gas with the liquid phase (A). A method for producing a Group 13 metal nitride crystal of the periodic table. The method for producing a periodic table group 13 metal nitride crystal according to claim 1, wherein the crystal is grown on a seed crystal surface or a substrate in the vicinity of the reaction field. The periodic table group 13 metal nitride crystal according to any one of claims 1 to 11, wherein the group 13 metal nitride crystal is grown using a container containing magnesium oxide or calcium oxide. Manufacturing method. The method for producing a periodic table group 13 metal nitride crystal according to any one of claims 1 to 12, wherein the metal element other than group 13 of the periodic table is an alkali metal or an alkaline earth metal. . The said molten salt is a metal halide, The manufacturing method of the periodic table group 13 metal nitride crystal | crystallization as described in any one of Claims 1-5 or 7-13 characterized by the above-mentioned. The said liquid phase (A) and / or the said liquid phase (b1) contain the simple substance or compound containing a dopant element, The periodic table group 13 as described in any one of Claims 1-14 characterized by the above-mentioned. A method for producing metal nitride crystals. A method for manufacturing a semiconductor device, comprising a step of manufacturing a Group 13 metal nitride crystal by the manufacturing method according to claim 1.