WO2012002545A1 - Device for producing aluminum nitride crystal grains, method for producing aluminum nitride crystal grains, and aluminum nitride crystal grains - Google Patents

Device for producing aluminum nitride crystal grains, method for producing aluminum nitride crystal grains, and aluminum nitride crystal grains Download PDF

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WO2012002545A1
WO2012002545A1 PCT/JP2011/065221 JP2011065221W WO2012002545A1 WO 2012002545 A1 WO2012002545 A1 WO 2012002545A1 JP 2011065221 W JP2011065221 W JP 2011065221W WO 2012002545 A1 WO2012002545 A1 WO 2012002545A1
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nitride crystal
aluminum nitride
aluminum
reaction chamber
crystal particles
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PCT/JP2011/065221
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French (fr)
Japanese (ja)
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原　和彦
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国立大学法人静岡大学
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    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
    • C30B29/60—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape characterised by shape
    • C30B29/605—Products containing multiple oriented crystallites, e.g. columnar crystallites
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B25/00—Single-crystal growth by chemical reaction of reactive gases, e.g. chemical vapour-deposition growth
    • C30B25/005—Growth of whiskers or needles
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
    • C30B29/60—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape characterised by shape
    • C30B29/66—Crystals of complex geometrical shape, e.g. tubes, cylinders

Definitions

  • the present invention relates to an apparatus for producing aluminum nitride crystal particles, a method for producing aluminum nitride crystal particles, and aluminum nitride crystal particles.
  • Aluminum nitride crystal particles are used as a raw material for electronic device substrates and ceramics for high temperature / high corrosion resistance structural materials (eg, AlN, SiAlON, etc.).
  • Examples of the method for producing aluminum nitride crystal particles include a reduction nitriding method and a combustion method.
  • Patent Document 1 discloses a method for producing an aluminum nitride phosphor by burning and synthesizing a raw material containing aluminum in an atmosphere containing nitrogen.
  • Patent Document 2 discloses a method of producing an aluminum nitride-based phosphor by nitriding a raw material containing an aluminum component in an atmosphere containing nitrogen and then firing at a temperature exceeding 1050 ° C.
  • Non-Patent Document 1 describes the powder synthesis of aluminum nitride.
  • Non-Patent Document 2 describes an aluminum nitride phosphor.
  • Non-Patent Documents 3 and 4 describe production of an aluminum nitride thin film using aluminum chloride gas and ammonia gas.
  • crystals obtained by the above-described methods are polycrystalline, and it is difficult to produce single crystal aluminum nitride crystal particles.
  • Polycrystalline aluminum nitride crystal particles cannot be used as a seed crystal for growing large aluminum nitride crystals.
  • the polycrystalline aluminum nitride crystal particles cannot achieve a significant increase in efficiency of the phosphor based on the aluminum nitride crystal particles.
  • the present invention provides an apparatus for producing aluminum nitride crystal particles capable of efficiently producing single-crystal aluminum nitride crystal particles, a method for producing aluminum nitride crystal particles using the production apparatus, and production according to the present invention.
  • An object of the present invention is to provide aluminum nitride crystal particles produced by a production method using an apparatus.
  • the aluminum nitride crystal particles according to the present embodiment are any one of hexagonal columns, hexagonal drums, hexagonal frustums, and shapes in which the bottoms of two hexagonal frustums are joined to each other.
  • the particle size is 0.05 ⁇ m or more and 1 ⁇ m or less.
  • the apparatus for producing aluminum nitride crystal particles includes a first reaction chamber that generates hydrogen chloride gas by reacting hydrogen chloride gas with aluminum heated to a temperature equal to or lower than the melting point, and ammonia gas.
  • a second reaction chamber in which aluminum nitride gas particles are grown by reacting with aluminum chloride gas a heating device for heating the first reaction chamber and the second reaction chamber, ammonia gas and aluminum chloride gas And a shroud for isolating the second reaction chamber.
  • aluminum chloride is used for producing aluminum nitride crystal particles.
  • generation of AlCl (aluminum chloride) which corrodes quartz glass can be suppressed by making the temperature of aluminum into the temperature below melting
  • the first reaction chamber is isolated from the ammonia gas by the shroud. Thereby, even when the temperature of the second reaction chamber becomes a high temperature of, for example, 1350 ° C. or higher, it is possible to prevent the aluminum installed in the first reaction chamber from being heated to a temperature higher than the melting point. .
  • the aluminum nitride crystal particles referred to herein may be collected by a fibrous filter installed in the exhaust pipe. Thereby, aluminum nitride crystal particles can be efficiently collected.
  • the temperature of the second reaction chamber may be within a range of 1350 ° C. or higher and 1450 ° C. or lower. Thereby, the particle diameter of the manufactured aluminum nitride crystal particle can be made uniform.
  • the aluminum installed in the first reaction chamber isolated from the ammonia gas by the shroud is heated to a temperature below the melting point of the aluminum, and the aluminum and the first Reacting with hydrogen chloride gas supplied to the reaction chamber, generating aluminum chloride gas in the first reaction chamber, reacting the aluminum chloride gas and ammonia gas in the second reaction chamber, and Aluminum nitride crystal grains are grown in two reaction chambers.
  • aluminum chloride is used for producing aluminum nitride crystal particles.
  • generation of AlCl (aluminum chloride) which corrodes quartz glass can be suppressed by making the temperature of aluminum into the temperature below melting
  • the first reaction chamber is isolated from ammonia gas by a shroud. Thereby, even when the temperature of the second reaction chamber becomes a high temperature of, for example, 1350 ° C. or higher, it is possible to prevent the aluminum installed in the first reaction chamber from being heated to a temperature higher than the melting point. .
  • the aluminum nitride crystal particles referred to herein may be collected by a fibrous filter installed in the exhaust pipe. Thereby, aluminum nitride crystal particles can be efficiently collected.
  • the temperature of the second reaction chamber may be within a range of 1350 ° C. or higher and 1450 ° C. or lower. Thereby, the particle diameter of the manufactured aluminum nitride crystal particle can be made uniform.
  • the aluminum installed in the first reaction chamber isolated from the ammonia gas by the shroud is heated to a temperature not higher than the melting point of the aluminum, and the chloride supplied to the first reaction chamber is supplied. Reaction with hydrogen gas generates aluminum chloride gas in the first reaction chamber, reaction of aluminum chloride gas and ammonia gas in the second reaction chamber, and growth of aluminum nitride crystal particles in the second reaction chamber Manufactured.
  • the above-mentioned aluminum nitride crystal particles are produced in a state where the first reaction chamber is isolated from the ammonia gas by the shroud. Thereby, even when the temperature of the second reaction chamber becomes a high temperature of, for example, 1350 ° C. or higher, the aluminum installed in the first reaction chamber is prevented from being heated to a temperature higher than the melting point. Can be manufactured.
  • the aluminum nitride crystal particles described above the aluminum nitride crystal particles can be used as a seed crystal for growing a large aluminum nitride crystal, which was impossible with conventional polycrystalline aluminum nitride crystal particles.
  • the shape of the aluminum nitride crystal particles may be an independent hexagonal column or hexagonal drum shape, and the particle size of the aluminum nitride crystal particles may be 0.05 ⁇ m or more and 1 ⁇ m or less.
  • the aluminum nitride crystal particles obtained in the present invention can be used for luminescent materials, polishing materials, high thermal conductive materials, paints, inks, and the like.
  • desired characteristics in each industrial application can be obtained, and the present invention is extremely useful.
  • it is useful as a starting material for industrially producing a composite material obtained by superimposing gallium nitride, a polymer or the like on the aluminum nitride crystal obtained in the present invention.
  • FIG. 1 is a schematic diagram showing a configuration of a manufacturing apparatus used in the method of the first embodiment.
  • FIG. 2 is a diagram showing an example of the temperature distribution in the reaction chamber.
  • FIG. 3 is a table showing combinations of gas flow rates and reaction chamber temperatures.
  • FIG. 4 is a graph showing the results of X-ray diffraction measurement of the produced crystal particles.
  • FIG. 5 is a scanning electron micrograph of the produced crystal particles.
  • FIG. 6 shows a scanning electron micrograph of commercially available aluminum nitride crystal particles as a comparative example.
  • FIG. 7 is a scanning electron micrograph of the produced crystal particles.
  • FIG. 8 is a graph showing the relationship between the electron beam excited luminescence intensity and the wavelength of the produced crystal particles.
  • FIG. 1 is a schematic diagram showing a configuration of a manufacturing apparatus used in the method of the first embodiment.
  • FIG. 2 is a diagram showing an example of the temperature distribution in the reaction chamber.
  • FIG. 3 is a table showing combinations of gas
  • FIG. 9 is a graph showing the results of X-ray diffraction measurement of the produced crystal particles.
  • FIG. 10 is a scanning electron micrograph of the produced crystal particles.
  • FIG. 11 shows, as a comparative example, the temperature of the reaction chamber in the case where aluminum aluminum crystal particles were produced by reacting this metal aluminum with N 2 or NH 3 gas using evaporated aluminum as an aluminum raw material. It is a graph which shows the relationship with the full width at half maximum of X-ray diffraction.
  • FIG. 12A shows an SEM photograph of aluminum crystal particles in the case where metallic aluminum and NH 3 gas are reacted.
  • FIG. 12B shows an SEM photograph of aluminum crystal particles when metallic aluminum and N 2 gas are reacted.
  • FIG. 13 is a schematic diagram illustrating a configuration of a manufacturing apparatus used in the method of the second embodiment.
  • FIG. 14 is a graph showing an example of the temperature distribution in the reaction chamber.
  • FIG. 15 shows the sample numbers of the aluminum nitride crystal particles produced in the seventh example, the set temperature in the reaction chamber, the hydrogen chloride gas flow rate, the presence or absence of the inner tube, and the position of the tip of the nozzle for each sample number. It is a graph which shows the position of the front-end
  • FIG. 16 is a graph showing the influence on the crystallinity of aluminum nitride crystal particles with and without the inner tube.
  • FIG. 17 is an SEM photograph of aluminum nitride crystal particles when there is no inner tube.
  • FIG. 18 is an SEM photograph of aluminum nitride crystal particles in the case where there is an inner tube.
  • FIG. 19 is a graph showing the influence of the set temperature in the reaction chamber on the crystallinity of the aluminum nitride crystal particles.
  • 20 (a) and 20 (b) are SEM photographs of aluminum nitride crystal grains in samples # 101 and # 102, respectively.
  • FIG. 21A and FIG. 21B are SEM photographs of aluminum nitride crystal grains in Samples # 103 and # 104, respectively.
  • FIGS. 22A and 22B are SEM photographs of aluminum nitride crystal grains in Samples # 111 and # 112, respectively.
  • FIG. 23 (a) is an SEM photograph of aluminum nitride crystal particles in sample # 115
  • FIG. 23 (b) is an enlarged SEM photograph of FIG. 23 (a)
  • FIG. It is the SEM photograph which expanded further.
  • FIG. 24 is a graph showing the influence of the flow rate of hydrogen chloride gas on the crystallinity of aluminum nitride crystal particles.
  • FIG. 25 is an SEM photograph of aluminum nitride crystal particles in Sample # 113.
  • FIG. 26A is an SEM photograph of aluminum nitride crystal particles in Sample # 116.
  • FIG. 26B is an enlarged SEM photograph of FIG. 26A
  • FIG. 26C is an enlarged SEM photograph of FIG. 26B.
  • FIG. 27 is a scanning electron microscope (SEM) photograph of sample # 108.
  • FIG. 28 is a histogram showing (a) particle size distribution and (b) thickness distribution of sample # 108 obtained by measuring individual aluminum nitride crystal particles included in the photograph of FIG.
  • FIG. 29 is an SEM photograph of sample # 112.
  • FIG. 30 is a histogram showing (a) particle size distribution and (b) thickness distribution of sample # 112 obtained from the photograph of FIG.
  • FIG. 31 is an SEM photograph of sample # 113.
  • FIG. 32 is a histogram showing (a) particle size distribution and (b) thickness distribution of Sample # 113 obtained from the photograph of FIG.
  • FIG. 33A and FIG. 33B are photographs in which a part of each SEM photograph of the sample # 113 shown in FIG.
  • FIG. 34 shows the intensity and light of electron beam excitation luminescence (CL) of aluminum nitride crystal particles in each of samples # 104, # 108, # 109, # 110, # 111, # 112, and # 113 according to this example. It is the result of having measured the relationship with the wavelength.
  • CL electron beam excitation luminescence
  • FIG. 1 is a schematic diagram showing the configuration of a manufacturing apparatus 1A used in this method.
  • This manufacturing apparatus 1A is an apparatus for manufacturing crystal particles by a vapor phase method.
  • the production apparatus 1A includes a reaction tube 2, a heating device 3, gas lines 4 to 6, a shroud 9, and an exhaust pipe 12.
  • the reaction tube 2 has a second reaction chamber 2a and a reaction vessel 7 inside.
  • the heating device 3 is installed around a part of the reaction tube 2 in the height direction.
  • an electric tubular furnace is suitable as the heating device 3.
  • the gas line 4 is a pipe for supplying ammonia gas to the reaction chamber 2a, and is installed on the wall surface near the end face 2b of the reaction pipe 2.
  • the gas line 5 is a tube for supplying hydrogen chloride gas to the inside of the reaction vessel 7, and is installed on the end surface 2 b of the reaction tube 2.
  • the gas line 6 is a tube for supplying nitrogen gas to the reaction chamber 2 a and is installed on the end surface 2 b of the reaction tube 2.
  • the inside of the reaction vessel 7 is a first reaction chamber 7a.
  • the reaction chamber 7a is an area for generating aluminum chloride gas (AlCl 3 ).
  • the reaction vessel 7 is installed closer to the end surface 2 b than the lower end 3 a of the heating device 3.
  • the front end of the gas line 5 is connected to the end surface 7 b near the end surface 2 b of the reaction vessel 7.
  • a nozzle 10 is connected to the other end surface 7 c facing the end surface 7 b of the reaction vessel 7.
  • the nozzle 10 extends from the end surface 7c of the reaction vessel 7 to the reaction chamber 2a.
  • Aluminum which is the raw material 8 is installed in the reaction chamber 7a. Further, a thermocouple 11 is inserted into the reaction chamber 7 a from the gas line 5, and the tip of the thermocouple 11 is installed at the position of the raw material 8.
  • the shroud 9 is disposed inside the reaction tube 2 and extends from the end surface 2 b to a position between the reaction vessel 7 and the tip of the nozzle 10.
  • the reaction vessel 7 is installed inside the shroud 9. Further, the ammonia gas supplied from the gas line 4 passes through a gap between the wall surface of the reaction tube 2 and the shroud 9 and is guided to the reaction chamber 2a. Therefore, the aluminum chloride gas generated in the reaction chamber 7 a is isolated from the ammonia gas by the shroud 9.
  • the exhaust pipe 12 is installed on the other end face 2c facing the end face 2b of the reaction tube 2 in order to discharge the residual gas generated as a result of the reaction in the reaction chamber 2a.
  • a fibrous filter 13 is provided at the tip of the exhaust pipe 12.
  • the fibrous filter 13 collects aluminum nitride crystal particles generated as a result of the reaction.
  • the fiber filter 13 for example, a silica fiber filter or a glass fiber filter is suitable.
  • FIG. 2 is an example showing the temperature distribution in the reaction chamber 2a.
  • the graph on the left side of FIG. 2 shows the temperature distribution in the height direction of the reaction chamber 2a.
  • A is the position of the lower end 3 a of the heating device 3.
  • the distance in the height direction of the reaction tube 2 is set to A as the coordinate origin.
  • B is the position of the tip of the nozzle 10 and the distance from A is 185 mm.
  • C is the position of the upper end of the heating device 3, and the distance from A is 625 mm.
  • D is the position of the fibrous filter 13, and the distance from A is 695 mm. Referring to the graph of FIG. 2, it can be seen that a uniform temperature distribution of about 1400 ° C. (1350 ° C.
  • the temperature of the reaction chamber 2a is heated within the range of 1350 ° C. or higher and 1450 ° C. or lower by the heating device 3, for example.
  • aluminum which is the raw material 8 installed in the reaction chamber 7a, is heated within a temperature range of, for example, 580 ° C. or more and below the melting point of aluminum (eg 600 ° C.). Therefore, aluminum does not dissolve completely.
  • the temperature of aluminum installed in the reaction chamber 7 a is measured by the thermocouple 11. The distance between the reaction vessel 7 and the heating device 3 is adjusted so that the temperature of aluminum is not lower than 580 ° C. and not higher than the melting point of aluminum.
  • ammonia gas is supplied from the gas line 4 to the reaction chamber 2a.
  • the ammonia gas and the aluminum chloride gas led out by the nozzle 10 react in the reaction chamber 2a heated to a temperature in the range of 1350 ° C. or higher and 1450 ° C. or lower to produce aluminum nitride crystal particles ( AlCl 3 + NH 3 ⁇ AlN + 3HCl).
  • the produced aluminum nitride crystal particles are collected by the fibrous filter 13.
  • the produced aluminum nitride crystal particles have a particle size of 0.05 ⁇ m or more and 1 ⁇ m or less.
  • the suitable temperature range of the fibrous filter 13 is 400 degreeC or more and 800 degrees C or less, for example.
  • aluminum chloride is used for producing aluminum nitride crystal particles.
  • evaporated aluminum is used for the production of aluminum nitride crystal particles, but it has been difficult to obtain single crystal aluminum nitride crystal particles by this method.
  • generation of AlCl (aluminum chloride) which corrodes quartz glass can be suppressed by making the temperature of aluminum below melting
  • the apparatus for producing aluminum nitride crystal particles according to the present embodiment is an apparatus using a vapor phase method, it can be continuously synthesized and can be easily applied to mass production. Furthermore, in this embodiment, the shroud 9 can prevent the aluminum installed in the first reaction chamber 7a from being heated to a temperature equal to or higher than the melting point.
  • the aluminum nitride crystal particles can be efficiently collected by the fibrous filter 13.
  • the particle diameter of the manufactured aluminum nitride crystal particle can be made uniform by making aluminum chloride gas and ammonia gas react within the range of 1350 degreeC or more and 1450 degrees C or less.
  • aluminum chloride is used for producing the aluminum nitride crystal particles.
  • evaporated aluminum is used for producing aluminum nitride crystal particles, but it is difficult to obtain single crystal aluminum nitride crystal particles by this method.
  • generation of AlCl (aluminum chloride) which corrodes quartz glass can be suppressed by making the temperature of aluminum below melting
  • the method for producing aluminum nitride crystal particles according to the present embodiment is a vapor phase method, continuous synthesis is possible, and application to mass production can be easily performed. Furthermore, in this embodiment, the shroud 9 can prevent the aluminum installed in the first reaction chamber 7a from being heated to a temperature equal to or higher than the melting point.
  • the aluminum nitride crystal particles can be efficiently collected by the fibrous filter 13.
  • the particle diameter of the manufactured aluminum nitride crystal particle can be made uniform by making aluminum chloride gas and ammonia gas react within the range of 1350 degreeC or more and 1450 degrees C or less.
  • the aluminum nitride crystal particles described above are produced in a state where the reaction chamber 7a is isolated from the ammonia gas by the shroud 9. Thereby, even when the temperature of the reaction chamber 2a becomes a high temperature of, for example, 1350 ° C. or higher, the aluminum installed in the reaction chamber 7a is manufactured in a state in which it is prevented from being heated to a temperature higher than the melting point. Can do.
  • the aluminum nitride crystal particles according to the present embodiment described above can be used as a seed crystal for growing a large aluminum nitride crystal, which was impossible with conventional polycrystalline aluminum nitride crystal particles.
  • the large aluminum nitride single crystal can be used as an epitaxial growth substrate for GaN-based light emitting and electronic devices.
  • single crystal aluminum nitride crystal particles with excellent crystallinity it has been difficult to achieve high efficiency of phosphors based on aluminum nitride, which was difficult with conventional polycrystalline aluminum nitride crystal particles. Can be planned.
  • Example 1 A manufacturing apparatus 1A including a high-purity alumina vertical reaction tube having an inner diameter of 60 mm and a height of 1000 mm as the reaction tube 2 and an electric tubular furnace having a heating unit length of 500 mm was prepared as the heating device 3.
  • the reaction tube 2 is installed so that the direction of acceleration of gravity and the height direction of the reaction tube 2 are along each other, and nitrogen gas, hydrogen chloride gas, and ammonia gas are supplied from the gas lines 4 to 6 installed near the end surface 2b.
  • the gas that is supplied and generated as a result of the reaction is exhausted from the exhaust pipe 12 installed near the end face 2c.
  • the raw material 8 used is metallic aluminum.
  • the gases used are 20% nitrogen diluted hydrogen chloride gas, ammonia gas and nitrogen gas.
  • samples a, b, and c were manufactured by setting three different conditions using the temperature of the reaction chamber 2a and the flow rates of nitrogen gas, hydrogen chloride gas, and ammonia gas as variables.
  • FIG. 3 is a table showing correspondence between three different conditions and samples a, b, and c.
  • the unit of the gas flow rate is the gas flow rate when the volume in the standard state per minute is expressed in cubic centimeters.
  • nitrogen gas is supplied from the gas line 6 to the reaction chamber 2a at a flow rate of 1730 sccm, and the temperature of the reaction chamber 2a is heated to 1450 ° C. while forming a flow of nitrogen gas in the reaction chamber 2a.
  • heating is performed so that the temperature of the metal aluminum installed in the reaction chamber 7a is about 600 ° C.
  • hydrogen chloride gas diluted with 20% nitrogen gas is supplied from the gas line 5 installed on the end face 2b of the reaction tube 2 to the reaction chamber 7a at a flow rate of 20 sccm.
  • aluminum chloride gas is generated (Al + 3HCl ⁇ AlCl 3 + 1.5H 2 ).
  • ammonia gas is supplied from the gas line 4 to the reaction chamber 2a at a flow rate of 250 sccm, and ammonia gas and aluminum chloride gas are reacted in the 1450 ° C. region of the reaction chamber 2a to produce aluminum nitride crystal particles ( AlCl 3 + NH 3 ⁇ AlN + 3HCl).
  • Aluminum nitride crystal particles are collected by the glass fiber filter 13.
  • FIG. 4 shows the results of X-ray diffraction measurement (XRD method) for the manufactured samples a, b, and c.
  • XRD method X-ray diffraction measurement
  • FIG. 5 is a scanning electron micrograph of aluminum nitride crystal particles produced under the conditions of a, b and c in FIG.
  • (a) is a photograph of sample a
  • (b) is a photograph of sample b
  • (c) is a photograph of sample c.
  • most of the particles are six-fold symmetrical hexagonal cylinders or hexagonal drums reflecting the wurtzite structure, and a high proportion of single crystal aluminum nitride crystal particles are produced.
  • the hexagonal drum shape refers to a three-dimensional shape in which the cross-sectional shape of the region sandwiched between the hexagonal end faces is a hexagon, and the hexagon is smaller than the hexagon on the end face.
  • the particle size of an aluminum nitride crystal grain is about 0.05 micrometer or more and 0.8 micrometer or less.
  • FIG. 6 shows a scanning electron micrograph of commercially available aluminum nitride crystal particles as a comparative example.
  • the aluminum nitride crystal particles produced by this example are particles having a very high crystallinity (single crystal) as compared with the conventional one. .
  • Example 2 Aluminum nitride crystal particles were produced under conditions different from those shown in Example 1. First, the manufacturing apparatus 1A similar to Example 1 was prepared. The raw material 8 used is metallic aluminum. The gases used are 20% nitrogen diluted hydrogen chloride gas, ammonia gas and nitrogen gas.
  • nitrogen gas (flow rate: 980 sccm to 1780 sccm) is supplied from the gas line 6 to the reaction chamber 2a, and while the nitrogen gas flow is formed in the reaction chamber 2a, the temperature of the reaction chamber 2a is heated to 1450 ° C. In parallel with this, heating is performed so that the temperature of the metallic aluminum is about 600 ° C.
  • a gas mixed with hydrogen chloride gas having a flow rate of 4 sccm and nitrogen gas having a flow rate of 16 sccm is reacted from the gas line 5 installed on the end surface 2b of the reaction tube 2. It supplies to the chamber 7a, and hydrogen chloride gas and metal aluminum are reacted to generate aluminum chloride gas (Al + 3HCl ⁇ AlCl 3 + 1.5H 2 ).
  • a gas obtained by mixing ammonia gas and nitrogen gas is supplied from the gas line 4 to the reaction chamber 2a.
  • the flow rate of ammonia gas is 250 sccm or more and 1000 sccm or less, and the flow rate of nitrogen gas is, for example, 0 sccm.
  • Ammonia gas and aluminum chloride gas are reacted in the reaction chamber 2a to produce aluminum nitride crystal particles (AlCl 3 + NH 3 ⁇ AlN + 3HCl). The produced particles are collected by the silica fibrous filter 13.
  • the flow rate of nitrogen gas supplied from the gas lines 4 and 6 is 980 sccm or more and 1730 sccm or less in total.
  • the aluminum nitride crystal particles were a single crystal and had a wurtzite hexagonal prism shape and hexagonal drum shape.
  • the particle size was 0.05 ⁇ m or more and 0.8 ⁇ m or less.
  • the largest particles were about 0.8 ⁇ m in diameter and length, and the average length of the particles was about 0.3 ⁇ m.
  • FIG. 7 is a scanning electron micrograph of aluminum nitride crystal particles produced at a reaction chamber 2a temperature of 1400 ° C.
  • the flow rate of the nitrogen gas supplied from the gas line 6 is 500 sccm
  • the flow rate of the hydrogen chloride gas supplied from the gas line 5 is 4 sccm (20 sccm in total with the dilution nitrogen gas)
  • the gas The flow rates of ammonia gas and nitrogen gas supplied from the line 4 were 1000 sccm and 480 sccm, respectively.
  • the particle A is a complete single crystal particle
  • the particle B may be a particle in which two single crystal grains whose c-axis directions are exactly opposite are combined.
  • one of the surface C and the surface D is a (0001) Al surface and the other is a (0001) N surface.
  • the crystal orientation can be determined by analyzing the diffraction spot shape measured by a transmission electron microscope (TEM).
  • FIG. 8 shows the results of measuring the relationship between the intensity of electron beam excited luminescence (Cathodo Luminescence) of the aluminum nitride crystal particles produced at a reaction chamber 2a temperature of 1500 ° C. and the wavelength of the light. Referring to FIG. 8, it can be seen that the wavelength of the maximum emission intensity is about 375 nm. This wavelength varies somewhat depending on the manufacturing conditions.
  • the flow rate of the nitrogen gas supplied from the gas line 6 is 500 sccm
  • the flow rate of the hydrogen chloride gas supplied from the gas line 5 is 4 sccm (20 sccm in total with the dilution nitrogen gas)
  • the gas The flow rates of ammonia gas and nitrogen gas supplied from the line 4 were 1000 sccm and 480 sccm, respectively.
  • Example 5 In order to investigate the influence of the partial pressure of ammonia gas on the formation of aluminum nitride crystal grains, the following experiment was conducted. First, the manufacturing apparatus 1A similar to Example 1 was prepared. Metal aluminum was placed in the reaction chamber 7a and heated until the metal aluminum reached about 600 ° C. Thereafter, hydrogen chloride gas was supplied to the reaction chamber 7a at a flow rate of 4 sccm to generate aluminum chloride gas. Then, it heated until the temperature of the reaction chamber 2a became 1450 degreeC, the aluminum chloride gas and the ammonia gas supplied from the gas line 4 were made to react, and the aluminum nitride crystal particle was manufactured. In Example 5, the flow rate of ammonia gas and the partial pressure of ammonia gas were changed. Here, the partial pressure of ammonia gas was changed by mixing nitrogen gas with ammonia gas.
  • FIG. 9 shows the results of X-ray diffraction measurement of aluminum nitride crystal particles produced under different partial pressure conditions.
  • graph Ga shows the case where the partial pressure of ammonia is 0.25 atm
  • graph Gb shows the case where the partial pressure of ammonia is 0.125 atm.
  • FIG. 10 is an electron micrograph of aluminum nitride crystal particles produced under different partial pressure conditions.
  • FIG. 10A is a photograph when the partial pressure of ammonia is 0.125 atm
  • FIG. 10B is a photograph when the partial pressure of ammonia is 0.25 atm. Referring to FIG.
  • the produced crystal particles are many single crystal particles having a 6-fold symmetrical shape reflecting the wurtzite structure. Further, comparing FIG. 10A and FIG. 10B, it was found that the particle size tends to increase as the partial pressure of ammonia gas decreases. This is thought to be because the growth of particles was promoted compared to the generation of minute nuclei.
  • the flow rate of nitrogen gas supplied from the gas line 6 is 1480 sccm
  • the flow rate of hydrogen chloride gas supplied from the gas line 5 is 4 sccm (20 sccm in total with the nitrogen gas for dilution)
  • the gas The flow rates of ammonia gas and nitrogen gas supplied from line 4 are 500 sccm and 0 sccm, respectively (when the partial pressure of ammonia is 0.250 atm), or 250 sccm and 250 sccm, respectively (when the partial pressure of ammonia is 0.125 atm) It was.
  • aluminum chloride is suitable as a material for producing single crystal aluminum nitride crystal particles.
  • FIG. 11 shows, as a comparative example, a reaction chamber in the case where aluminum nitride crystal particles are produced by reacting evaporated metal aluminum as an aluminum raw material and reacting this metal aluminum with N 2 or NH 3 gas. It is a graph which shows the relationship between the temperature of 2a, and the full width at half maximum (FWHM, unit: degree) of (100) X-ray diffraction.
  • FIG. 12A shows a scanning electron microscope (SEM) photograph of aluminum crystal particles in the case of reacting metallic aluminum with NH 3 gas
  • FIG. 12B shows metallic aluminum and N 2. The SEM photograph of the aluminum crystal particle at the time of making it react with gas is shown. As shown in FIGS.
  • FIG. 13 is a schematic diagram showing the configuration of the manufacturing apparatus 1B used in the present method.
  • This manufacturing apparatus 1B is an apparatus for manufacturing crystal particles by a vapor phase method.
  • the difference between the manufacturing apparatus 1A of the first embodiment and the manufacturing apparatus 1B of the present embodiment is the shape of the shroud. That is, the shroud 19 of this embodiment has a main body 19a and an inner tube 19b.
  • the main body 19 a is a cylindrical member that extends in the longitudinal direction of the reaction tube 2.
  • the main body portion 19 a is disposed inside the reaction tube 2 and extends from the bottom surface of the reaction tube 2 to a position between the reaction vessel 7 and the tip of the nozzle 10.
  • the reaction vessel 7 is installed inside the main body 19a.
  • the inner tube 19b is a cylindrical member extending in the longitudinal direction of the reaction tube 2, and is located near the position of the tip of the nozzle 10 from the position between the reaction vessel 7 and the tip of the nozzle 10 in the main body 19a. Has been stretched to The position of the distal end portion of the inner tube cylinder 19b in the longitudinal direction of the reaction tube 2 may be arranged closer to the reaction chamber 2a than the position of the distal end portion of the nozzle 10, and the main body is located more than the position of the distal end portion of the nozzle 10. It may be arranged on the part 19a side, and may be equal to the position of the tip of the nozzle 10.
  • the ammonia gas supplied from the gas line 4 passes through the space between the wall surface of the reaction tube 2 and the shroud 19 and is guided to the reaction chamber 2a. Therefore, until the ammonia gas reaches the reaction chamber 2a, the aluminum not dissolved in the reaction chamber 7a and the chlorine of the hydrogen chloride gas are combined, and in the gas phase, the stoichiometry of aluminum and chlorine is Al: It is isolated from aluminum chloride gas (hereinafter referred to as “aluminum trichloride gas”) generated in a combined state of Cl from 1: 1 to 1: 3 and nitrogen gas introduced from the gas line 6.
  • aluminum trichloride gas aluminum chloride gas
  • FIG. 14 is a graph showing an example of the temperature distribution in the reaction chamber 2a.
  • the vertical axis indicates the position in the longitudinal direction of the reaction tube 2, and the position (A) of the lower end 3 a of the heating device 3 is the origin.
  • the horizontal axis indicates the temperature.
  • B in a figure is a position of the front-end
  • C is the position of the upper end of the heating device 3, and the distance from A is, for example, 620 mm.
  • D is the position of the fibrous filter 13, and the distance from A is 695 mm, for example.
  • E is the position of the upper end of the reaction tube 2, and the distance from A is 1000 mm, for example.
  • each set temperature (1300 ° C., 1400 ° C., 1500 ° C.) is obtained at least in a region where the distance from A is 150 mm to 450 mm.
  • the temperature distribution in the region is in the range of 1350 ° C. to 1450 ° C.
  • the tip of the nozzle 10 and the tip of the shroud 19 are in a region where a uniform temperature distribution of each set temperature is obtained.
  • the aluminum trichloride gas supplied from the nozzle 10 and the ammonia gas supplied from the gas line 4 have a uniform temperature distribution region in the reaction chamber 2a (for example, 1350 ° C. when the set temperature is 1400 ° C. In the region of 1450 ° C. or lower).
  • the manufacturing method of the aluminum nitride crystal particle using the manufacturing apparatus 1B is the same as that of 1st Embodiment mentioned above. Therefore, the manufacturing apparatus 1B of the present embodiment and the method of manufacturing aluminum nitride crystal particles using the same can achieve the same effects as those of the first embodiment.
  • the inner tube 19 b is provided in the shroud 19, and the tip of the inner tube 19 b extends to the vicinity of the position of the tip of the nozzle 10.
  • the aluminum trichloride gas blown from the nozzle 10 the nitrogen gas blown from the gap between the nozzle 10 and the inner tube 19b, and the ammonia gas blown from the gap between the inner tube 19b and the inner wall of the reaction tube 2 are laminar. In this state, it can reach deep inside the reaction chamber 2a. During this time, the aluminum trichloride gas and the ammonia gas react slowly.
  • the generation of aluminum nitride crystal particles in the reaction chamber 2a is performed through the following process.
  • minute nuclei that form the basis for forming aluminum nitride crystal particles are generated.
  • these nuclei are single crystals or polycrystals, but most of them are single crystals under the reaction conditions of the first embodiment and this embodiment.
  • ammonia gas and aluminum trichloride gas crystals grow around the nuclei, and the particles gradually increase. At this time, if the nucleus is a single crystal, the grown particle is also a single crystal, and if the nucleus is polycrystalline, the grown particle is also polycrystalline.
  • aluminum trichloride gas and ammonia gas react slowly by the action of the inner tube 19b.
  • the milder the reaction between the aluminum trichloride gas and the ammonia gas the more the aluminum trichloride gas and the ammonia gas supplied into the reaction chamber 2a contribute to the generation of nuclei.
  • the ratio is suppressed, and the ratio contributing to particle growth increases. Therefore, relatively large aluminum nitride crystal particles can be more suitably produced.
  • the crystallization of the nuclei is also suppressed. Therefore, it is possible to more suitably manufacture aluminum nitride crystal particles made of a single crystal.
  • Example 7 In order to investigate the influence of the presence or absence of the inner tube 19b, the temperature in the reaction chamber, and the flow rate of hydrogen chloride gas on the formation of aluminum nitride crystal particles, the following experiment was performed.
  • the reaction tube 2 of the production apparatus 1B was a high-purity alumina vertical reaction tube having an inner diameter of 60 mm and a height of 1000 mm, and the length of the heating portion of the electric tubular furnace as the heating device 3 was 500 mm.
  • the outer diameter of the nozzle 10 was 6 mm, and the inner diameter was 4 mm.
  • the outer diameter of the inner tube 19b was 25 mm, and the inner diameter was 20 mm.
  • Metal aluminum was installed in the reaction chamber 7a and heated until the metal aluminum reached about 600 ° C. Thereafter, hydrogen chloride gas diluted with 20% nitrogen is supplied to the reaction chamber 7a at a flow rate of 15 sccm, 20 sccm, 25 sccm, and 50 sccm (3 sccm, 4 sccm, 5 sccm, and 10 sccm, respectively, when converted to the flow rate of hydrogen chloride gas only). Then, aluminum trichloride gas was generated.
  • the temperature of the reaction chamber 2a is set to any of 1300 ° C., 1350 ° C., 1400 ° C., 1450 ° C., and 1500 ° C., and the ammonia gas supplied from the gas line 4 is reacted with aluminum trichloride gas. Then, aluminum nitride crystal particles were produced.
  • the flow rate of nitrogen gas supplied from the gas line 6 is set to 500 sccm, and the flow rate of nitrogen gas supplied from the gas line 4 together with the ammonia gas is set to 1500 sccm together with the flow rate of hydrogen chloride gas diluted with 20% nitrogen. Set to.
  • FIG. 15 shows the sample numbers of the aluminum nitride crystal particles produced in this example, the set temperature in the reaction chamber, the hydrogen chloride gas flow rate, the presence or absence of the inner tube 19b, and the position of the tip of the nozzle 10 for each sample number.
  • the position of the tip of the inner tube 19b is provided on the end face 2b side with respect to the position of the tip of the nozzle 10
  • the position of the tip of the inner tube 19b was provided on the end face 2c side with respect to the position of the tip of the nozzle 10.
  • FIG. 16 is a graph showing the influence on the crystallinity of the aluminum nitride crystal particles with and without the inner tube 19b.
  • the horizontal axis represents the hydrogen chloride gas flow rate (unit: sccm), and the vertical axis represents the full width at half maximum (FWHM, unit: degree) of the X-ray diffraction result.
  • samples # 109 and # 110 are plotted when there is no inner tube 19b
  • samples # 108 and # 104 are plotted when there is an inner tube 19b.
  • FIG. 17 is an SEM photograph of aluminum nitride crystal particles when there is no inner tube 19b ((a) sample # 109, (b) sample # 110), and FIG. 18 shows a case where there is an inner tube 19b. It is a SEM photograph of the aluminum nitride crystal grain in ((a) sample # 108, (b) sample # 104).
  • the shroud 19 preferably has an inner tube 19b.
  • FIG. 19 is a graph showing the influence of the set temperature in the reaction chamber 2a on the crystallinity of the aluminum nitride crystal particles.
  • the horizontal axis indicates the set temperature (unit: degree) in the reaction chamber 2a
  • the vertical axis indicates the FWHM (unit: degree) of the X-ray diffraction result.
  • samples # 101, # 102, # 103, and # 104 with an HCl flow rate of 10 sccm are plotted, and samples # 108, # 111, # 112, # 114, with an HCl flow rate of 5 sccm, are plotted.
  • FIG. 23A is an SEM photograph of aluminum nitride crystal particles in Sample # 115
  • FIG. 23B is an enlarged SEM photograph of FIG. 23A
  • FIG. It is the SEM photograph which expanded (b) further.
  • the set temperature of the reaction chamber 2a is 1450 ° C. or lower, the FWHM of the X-ray diffraction result becomes smaller than 0.3, and sufficient crystallinity of the aluminum nitride crystal particles can be obtained. It was. Further, when the set temperature of the reaction chamber 2a was 1400 ° C., the FWHM of the X-ray diffraction result was the smallest. From this result, the set temperature of the reaction chamber 2a is preferably 1450 ° C. or less, more preferably 1400 ° C. (that is, the temperature distribution is included in the range of 1350 ° C. to 1450 ° C.).
  • FIG. 24 is a graph showing the influence of the flow rate of hydrogen chloride gas on the crystallinity of aluminum nitride crystal particles.
  • the horizontal axis indicates the hydrogen chloride gas flow rate (unit: sccm), and the vertical axis indicates the FWHM (unit: degree) of the X-ray diffraction result.
  • samples # 104, # 108, # 113 and # 116 in which the set temperature in the reaction chamber is 1400 ° C. are plotted.
  • FIG. 25 is an SEM photograph of aluminum nitride crystal particles in Sample # 113.
  • FIG. 26 (a) is an SEM photograph of aluminum nitride crystal particles in sample # 116
  • FIG. 26 (b) is an enlarged SEM photograph of FIG. 26 (a)
  • FIG. 26 (c) is FIG. It is the SEM photograph which expanded (b) further. Note that SEM photographs of samples # 104 and # 108 are shown in FIG.
  • FIG. 27 is an SEM photograph of sample # 108 (setting temperature 1400 ° C., HCl flow rate 5 sccm)
  • FIG. 28 is a view of sample # 108 obtained by measuring individual aluminum nitride crystal particles included in this photograph. It is a histogram which shows (a) particle size distribution and (b) thickness distribution.
  • FIG. 29 is an SEM photograph of sample # 112 (set temperature 1350 ° C., HCl flow rate 5 sccm), and FIG.
  • FIG. 30 shows (a) particle size distribution and (b) of sample # 112 obtained from this photograph. It is a histogram which shows thickness distribution.
  • FIG. 31 is a SEM photograph of sample # 113 (set temperature 1400 ° C., HCl flow rate 4 sccm), and
  • FIG. 32 shows (a) particle size distribution and (b) thickness of sample # 113 obtained from this photograph. It is a histogram which shows thickness distribution.
  • the particle size represents the interval between opposing sides in the planar shape (hexagon) of the aluminum nitride crystal particles, and the thickness is It represents the distance between a pair of end faces in a direction perpendicular to the planar shape of the aluminum nitride crystal particles.
  • the particle size of the aluminum nitride crystal particles is 0.1 ⁇ m or more and 1 It can be seen that it is within the range of 0.0 ⁇ m or less.
  • the thickness of the aluminum nitride crystal particles is within the range of 0.1 ⁇ m or more and 0.4 ⁇ m or less in the sample # 108. It can be seen that the sample # 112 falls within the range of 0.1 ⁇ m to 0.5 ⁇ m, and the sample # 113 falls within the range of 0.1 ⁇ m to 0.6 ⁇ m.
  • some of the aluminum nitride crystal particles produced according to this example include a hexagonal frustum (that is, A number of hexagonal pillars having an outer shape such that the side surface of the hexagonal column is inclined with respect to the bottom surface and the top surface were confirmed. Further, referring to these SEM photographs, a large number of hexagonal columnar shapes (typically those having a thickness smaller than the particle size) were confirmed. Further, referring to these SEM photographs, it was confirmed that the film had a hexagonal column shape, but the thickness was extremely smaller than the particle diameter, and had an outer shape such as a hexagonal plate shape.
  • 33 (a) and 33 (b) are photographs in which a part of each SEM photograph of sample # 113 shown in FIG. 31 is enlarged.
  • a number of shapes in which the bottom surfaces of two hexagonal frustums were combined were confirmed in the aluminum nitride crystal particles produced according to this example.
  • the aluminum nitride crystal particles have a pair of regular hexagonal end faces along a plane intersecting the thickness direction, and the cross section perpendicular to the thickness direction is a regular hexagon.
  • the diameter of the hexagonal cross section in the center part of thickness direction is larger than the diameter of a pair of hexagonal end surface.
  • FIG. 34 shows the intensity and light of electron beam excitation luminescence (CL) of aluminum nitride crystal particles in each of samples # 104, # 108, # 109, # 110, # 111, # 112, and # 113 according to this example. It is the result of having measured the relationship with the wavelength.
  • FIG. 34A shows graphs related to samples # 104, # 108, # 109, and # 110
  • FIG. 34B shows graphs related to samples # 108, # 111, # 112, and # 113.
  • CL intensities were measured in a room temperature environment, the electron beam acceleration voltage was 10 kV, the current density was 60 ⁇ A / cm 2 , and the measurement time was 100 ms.
  • the method for producing aluminum nitride crystal particles according to the present invention and the aluminum nitride crystal particles produced by the method are not limited to the above-described embodiments and examples, and various other modifications are possible.
  • the present invention uses an apparatus for producing aluminum nitride crystal particles capable of efficiently producing single-crystal aluminum nitride crystal particles, a method for producing aluminum nitride crystal particles using the production apparatus, and such a production apparatus. It can be used as aluminum nitride crystal particles produced by the production method.

Abstract

Provided are aluminum nitride crystal grains in which each individual grain has a grain size of 0.05 µm to 1 µm and a shape selected from any of a hexagonal prism, a hexagonal drum shape, a hexagonal pyramid, or two hexagonal pyramids where the base surfaces thereof are joined together. A production device (1A) comprises: a first reaction chamber (7a) for generating aluminum chloride gas by reacting hydrogen chloride gas and aluminum heated to a temperature that is the melting point of the aluminum or lower; a second reaction chamber (2a) for growing aluminum nitride crystal grains by reacting ammonia gas and the aluminum chloride gas; a heater (3) for heating the first reaction chamber (7a) and the second reaction chamber (2a); and a shroud (9) for separating the ammonia gas and the aluminum chloride gas up to the second reaction chamber (2a). As a result, a device for producing aluminum nitride crystal grains can be provided with which aluminum nitride crystal grains that are single crystals can be efficiently produced.

Description

窒化アルミニウム結晶粒子の製造装置、窒化アルミニウム結晶粒子の製造方法および窒化アルミニウム結晶粒子Aluminum nitride crystal particle manufacturing apparatus, aluminum nitride crystal particle manufacturing method, and aluminum nitride crystal particle
　本発明は、窒化アルミニウム結晶粒子の製造装置、窒化アルミニウム結晶粒子の製造方法および窒化アルミニウム結晶粒子に関する。 The present invention relates to an apparatus for producing aluminum nitride crystal particles, a method for producing aluminum nitride crystal particles, and aluminum nitride crystal particles.
　窒化アルミニウム結晶粒子は、電子素子の基板や高温・高耐食性構造材用セラミックス（例えばＡｌＮ、ＳｉＡｌＯＮなど）の原料に用いられている。窒化アルミニウム結晶粒子の製造方法としては、例えば還元窒化法や燃焼法がある。特許文献１には、アルミニウムを含む原料を、窒素を含む雰囲気中で燃焼合成させることにより窒化アルミニウム系蛍光体を製造する方法が開示されている。特許文献２には、アルミニウム成分を含む原料を、窒素を含む雰囲気中で窒化処理した後、１０５０℃を越える温度で焼成することにより窒化アルミニウム系蛍光体を製造する方法が開示されている。非特許文献１には、窒化アルミニウムの粉体合成について記載がある。非特許文献２には、窒化アルミニウム蛍光体について記載がある。非特許文献３，４には、塩化アルミニウムガスとアンモニアガスを用いる窒化アルミニウムの薄膜作製について記載がある。 Aluminum nitride crystal particles are used as a raw material for electronic device substrates and ceramics for high temperature / high corrosion resistance structural materials (eg, AlN, SiAlON, etc.). Examples of the method for producing aluminum nitride crystal particles include a reduction nitriding method and a combustion method. Patent Document 1 discloses a method for producing an aluminum nitride phosphor by burning and synthesizing a raw material containing aluminum in an atmosphere containing nitrogen. Patent Document 2 discloses a method of producing an aluminum nitride-based phosphor by nitriding a raw material containing an aluminum component in an atmosphere containing nitrogen and then firing at a temperature exceeding 1050 ° C. Non-Patent Document 1 describes the powder synthesis of aluminum nitride. Non-Patent Document 2 describes an aluminum nitride phosphor. Non-Patent Documents 3 and 4 describe production of an aluminum nitride thin film using aluminum chloride gas and ammonia gas.
特開２００５－５４１８２号公報JP 2005-54182 A 特開２００６－１９９８７６号公報JP 2006-199876 A
　しかしながら、上記した方法（非特許文献３，４を除く）で得られる結晶は多結晶であり、単結晶の窒化アルミニウム結晶粒子を製造することは困難である。また、多結晶の窒化アルミニウム結晶粒子は、大型窒化アルミニウム結晶育成用の種結晶として利用することができない。さらに、多結晶の窒化アルミニウム結晶粒子は、窒化アルミニウム結晶粒子を母体とする蛍光体の大幅な高効率化を図ることができない。 However, crystals obtained by the above-described methods (except for Non-Patent Documents 3 and 4) are polycrystalline, and it is difficult to produce single crystal aluminum nitride crystal particles. Polycrystalline aluminum nitride crystal particles cannot be used as a seed crystal for growing large aluminum nitride crystals. Furthermore, the polycrystalline aluminum nitride crystal particles cannot achieve a significant increase in efficiency of the phosphor based on the aluminum nitride crystal particles.
　本発明は、単結晶の窒化アルミニウム結晶粒子を効率よく製造することができる窒化アルミニウム結晶粒子の製造装置および該製造装置を用いた窒化アルミニウム結晶粒子の製造方法を提供すること、及び本発明による製造装置を用いた製造方法により製造された窒化アルミニウム結晶粒子を提供することを目的とする。 The present invention provides an apparatus for producing aluminum nitride crystal particles capable of efficiently producing single-crystal aluminum nitride crystal particles, a method for producing aluminum nitride crystal particles using the production apparatus, and production according to the present invention. An object of the present invention is to provide aluminum nitride crystal particles produced by a production method using an apparatus.
　本実施形態による窒化アルミニウム結晶粒子は、粒子の形状が各々独立した六角柱、六角鼓形、六角錐台、及び、２つの六角錐台の底面同士が結合された形状のうち何れかであり、粒径が０．０５μｍ以上１μｍ以下である。 The aluminum nitride crystal particles according to the present embodiment are any one of hexagonal columns, hexagonal drums, hexagonal frustums, and shapes in which the bottoms of two hexagonal frustums are joined to each other. The particle size is 0.05 μm or more and 1 μm or less.
　また、本実施形態による窒化アルミニウム結晶粒子の製造装置は、塩化水素ガスと、融点以下の温度に加熱されたアルミニウムとを反応させて、塩化アルミニウムガスを発生させる第１の反応室と、アンモニアガスと塩化アルミニウムガスとを反応させて、窒化アルミニウム結晶粒子を成長させる第２の反応室と、第１の反応室及び第２の反応室を加熱する加熱装置と、アンモニアガスと塩化アルミニウムガスとを第２の反応室まで隔離するシュラウドとを備えている。 In addition, the apparatus for producing aluminum nitride crystal particles according to the present embodiment includes a first reaction chamber that generates hydrogen chloride gas by reacting hydrogen chloride gas with aluminum heated to a temperature equal to or lower than the melting point, and ammonia gas. A second reaction chamber in which aluminum nitride gas particles are grown by reacting with aluminum chloride gas, a heating device for heating the first reaction chamber and the second reaction chamber, ammonia gas and aluminum chloride gas And a shroud for isolating the second reaction chamber.
　上記した窒化アルミニウム結晶粒子の製造装置では、窒化アルミニウム結晶粒子の製造に塩化アルミニウムを用いる。また、アルミニウムの温度を融点以下の温度にすることにより、石英ガラスを腐蝕させるＡｌＣｌ（アルミニウム塩化物）の生成を抑制することができる。これにより、単結晶の窒化アルミニウム結晶粒子を高い割合で含む粉末を製造することが可能となるため、単結晶の窒化アルミニウム結晶粒子を効率よく製造することができる。また、第１の反応室がシュラウドによりアンモニアガスから隔離されている。これにより、第２の反応室の温度が例えば１３５０℃以上の高温になる場合であっても、第１の反応室に設置されたアルミニウムが融点以上の温度に加熱されることを防ぐことができる。 In the above-described apparatus for producing aluminum nitride crystal particles, aluminum chloride is used for producing aluminum nitride crystal particles. Moreover, the production | generation of AlCl (aluminum chloride) which corrodes quartz glass can be suppressed by making the temperature of aluminum into the temperature below melting | fusing point. This makes it possible to produce a powder containing a single crystal aluminum nitride crystal particle at a high ratio, and therefore, single crystal aluminum nitride crystal particles can be produced efficiently. The first reaction chamber is isolated from the ammonia gas by the shroud. Thereby, even when the temperature of the second reaction chamber becomes a high temperature of, for example, 1350 ° C. or higher, it is possible to prevent the aluminum installed in the first reaction chamber from being heated to a temperature higher than the melting point. .
　なお、ここでいう窒化アルミニウム結晶粒子は、排気管に設置された繊維性フィルタにより捕集されてもよい。これにより、効率的に窒化アルミニウム結晶粒子を捕集することができる。 Note that the aluminum nitride crystal particles referred to herein may be collected by a fibrous filter installed in the exhaust pipe. Thereby, aluminum nitride crystal particles can be efficiently collected.
　なお、第２の反応室の温度は、１３５０℃以上１４５０℃以下の範囲内であってもよい。これにより、製造された窒化アルミニウム結晶粒子の粒径を均一にすることができる。 Note that the temperature of the second reaction chamber may be within a range of 1350 ° C. or higher and 1450 ° C. or lower. Thereby, the particle diameter of the manufactured aluminum nitride crystal particle can be made uniform.
　本実施形態による窒化アルミニウム結晶粒子の製造方法は、シュラウドによりアンモニアガスから隔離された第１の反応室に設置されたアルミニウムを該アルミニウムの融点以下の温度に加熱し、前記アルミニウムと前記第１の反応室へ供給された塩化水素ガスとを反応させて、前記第１の反応室で塩化アルミニウムガスを発生させ、前記塩化アルミニウムガスとアンモニアガスとを第２の反応室で反応させて、前記第２の反応室で窒化アルミニウム結晶粒子を成長させる。 In the method for producing aluminum nitride crystal particles according to the present embodiment, the aluminum installed in the first reaction chamber isolated from the ammonia gas by the shroud is heated to a temperature below the melting point of the aluminum, and the aluminum and the first Reacting with hydrogen chloride gas supplied to the reaction chamber, generating aluminum chloride gas in the first reaction chamber, reacting the aluminum chloride gas and ammonia gas in the second reaction chamber, and Aluminum nitride crystal grains are grown in two reaction chambers.
　上記した窒化アルミニウム結晶粒子の製造方法では、窒化アルミニウム結晶粒子の製造に塩化アルミニウムを用いる。また、アルミニウムの温度を融点以下の温度にすることにより、石英ガラスを腐蝕させるＡｌＣｌ（アルミニウム塩化物）の生成を抑制することができる。これにより、単結晶の窒化アルミニウム結晶粒子を高い割合で含む粉末を製造することが可能となるため、単結晶の窒化アルミニウム結晶粒子を効率よく製造することができる。また、第１の反応室はシュラウドによりアンモニアガスから隔離されている。これにより、第２の反応室の温度が例えば１３５０℃以上の高温になる場合であっても、第１の反応室に設置されたアルミニウムが融点以上の温度に加熱されることを防ぐことができる。 In the above method for producing aluminum nitride crystal particles, aluminum chloride is used for producing aluminum nitride crystal particles. Moreover, the production | generation of AlCl (aluminum chloride) which corrodes quartz glass can be suppressed by making the temperature of aluminum into the temperature below melting | fusing point. This makes it possible to produce a powder containing a single crystal aluminum nitride crystal particle at a high ratio, and therefore, single crystal aluminum nitride crystal particles can be produced efficiently. The first reaction chamber is isolated from ammonia gas by a shroud. Thereby, even when the temperature of the second reaction chamber becomes a high temperature of, for example, 1350 ° C. or higher, it is possible to prevent the aluminum installed in the first reaction chamber from being heated to a temperature higher than the melting point. .
　なお、ここでいう窒化アルミニウム結晶粒子は、排気管に設置された繊維性フィルタにより捕集されてもよい。これにより、効率的に窒化アルミニウム結晶粒子を捕集することができる。 Note that the aluminum nitride crystal particles referred to herein may be collected by a fibrous filter installed in the exhaust pipe. Thereby, aluminum nitride crystal particles can be efficiently collected.
　なお、第２の反応室の温度は、１３５０℃以上１４５０℃以下の範囲内であってもよい。これにより、製造された窒化アルミニウム結晶粒子の粒径を均一にすることができる。 Note that the temperature of the second reaction chamber may be within a range of 1350 ° C. or higher and 1450 ° C. or lower. Thereby, the particle diameter of the manufactured aluminum nitride crystal particle can be made uniform.
　本実施形態による窒化アルミニウム結晶粒子は、シュラウドによりアンモニアガスから隔離された第１の反応室に設置されたアルミニウムを該アルミニウムの融点以下の温度に加熱し、第１の反応室へ供給された塩化水素ガスと反応させて、第１の反応室で塩化アルミニウムガスを発生させ、塩化アルミニウムガスとアンモニアガスとを第２の反応室で反応させて、第２の反応室で窒化アルミニウム結晶粒子を成長させることにより製造される。 In the aluminum nitride crystal particles according to the present embodiment, the aluminum installed in the first reaction chamber isolated from the ammonia gas by the shroud is heated to a temperature not higher than the melting point of the aluminum, and the chloride supplied to the first reaction chamber is supplied. Reaction with hydrogen gas generates aluminum chloride gas in the first reaction chamber, reaction of aluminum chloride gas and ammonia gas in the second reaction chamber, and growth of aluminum nitride crystal particles in the second reaction chamber Manufactured.
　上記した窒化アルミニウム結晶粒子は、第１の反応室がシュラウドによりアンモニアガスから隔離されている状態で製造される。これにより、第２の反応室の温度が例えば１３５０℃以上の高温になる場合であっても、第１の反応室に設置されたアルミニウムが融点以上の温度に加熱されることを防いだ状態で製造されることができる。また、上記した窒化アルミニウム結晶粒子によれば、従来の多結晶の窒化アルミニウム結晶粒子では不可能であった大型窒化アルミニウム結晶育成用の種結晶として、窒化アルミニウム結晶粒子を利用することができる。また、結晶性の優れた単結晶の窒化アルミニウム結晶粒子を使用することにより、従来の多結晶の窒化アルミニウム結晶粒子では困難であった、窒化アルミニウムを母体とする蛍光体の大幅な高効率化を図ることができる。 The above-mentioned aluminum nitride crystal particles are produced in a state where the first reaction chamber is isolated from the ammonia gas by the shroud. Thereby, even when the temperature of the second reaction chamber becomes a high temperature of, for example, 1350 ° C. or higher, the aluminum installed in the first reaction chamber is prevented from being heated to a temperature higher than the melting point. Can be manufactured. In addition, according to the aluminum nitride crystal particles described above, the aluminum nitride crystal particles can be used as a seed crystal for growing a large aluminum nitride crystal, which was impossible with conventional polycrystalline aluminum nitride crystal particles. In addition, by using single crystal aluminum nitride crystal particles with excellent crystallinity, it has been difficult to achieve high efficiency of phosphors based on aluminum nitride, which was difficult with conventional polycrystalline aluminum nitride crystal particles. Can be planned.
　また、窒化アルミニウム結晶粒子の形状は、各々独立した六角柱又は六角鼓形であって、窒化アルミニウム結晶粒子の粒径は、０．０５μｍ以上１μｍ以下でもよい。 The shape of the aluminum nitride crystal particles may be an independent hexagonal column or hexagonal drum shape, and the particle size of the aluminum nitride crystal particles may be 0.05 μm or more and 1 μm or less.
　上述した窒化アルミニウム結晶粒子の製造装置、および該製造装置を用いた窒化アルミニウム結晶粒子の製造方法によれば、単結晶の窒化アルミニウム結晶粒子を効率よく製造することができ、上述した製造装置を用いた製造方法により製造された窒化アルミニウム結晶粒子を得ることができる。 According to the above-described production apparatus for aluminum nitride crystal particles and the production method for aluminum nitride crystal particles using the production apparatus, single crystal aluminum nitride crystal particles can be efficiently produced. Aluminum nitride crystal particles produced by the conventional production method can be obtained.
　本発明で得られた窒化アルミニウム結晶粒子は、発光材料、研磨材料、高熱伝導材料、塗料、インク等に用いることが出来る。本発明の製造装置、製造プロセスでの条件によって単結晶の粒径分布を制御する事によって、各々の工業的応用での所望の特性を得ることができ、本発明は極めて有用である。また、本発明で得られる窒化アルミニウム結晶に窒化ガリウム、ポリマー等を重ねることによって得られる複合素材を工業的に製造するための出発材料として有用である。 The aluminum nitride crystal particles obtained in the present invention can be used for luminescent materials, polishing materials, high thermal conductive materials, paints, inks, and the like. By controlling the particle size distribution of the single crystal according to the conditions of the production apparatus and production process of the present invention, desired characteristics in each industrial application can be obtained, and the present invention is extremely useful. Moreover, it is useful as a starting material for industrially producing a composite material obtained by superimposing gallium nitride, a polymer or the like on the aluminum nitride crystal obtained in the present invention.
図１は、第１実施形態の方法に用いられる製造装置の構成を示す概略図である。FIG. 1 is a schematic diagram showing a configuration of a manufacturing apparatus used in the method of the first embodiment. 図２は、反応室の温度分布の一例を示す図である。FIG. 2 is a diagram showing an example of the temperature distribution in the reaction chamber. 図３は、ガス流量と反応室温度の組み合わせを示す表である。FIG. 3 is a table showing combinations of gas flow rates and reaction chamber temperatures. 図４は、製造した結晶粒子のＸ線回折測定を行った結果を示すグラフである。FIG. 4 is a graph showing the results of X-ray diffraction measurement of the produced crystal particles. 図５は、製造した結晶粒子の走査電子顕微鏡写真である。FIG. 5 is a scanning electron micrograph of the produced crystal particles. 図６は、比較例として、市販の窒化アルミニウム結晶粒子の走査電子顕微鏡写真を示している。FIG. 6 shows a scanning electron micrograph of commercially available aluminum nitride crystal particles as a comparative example. 図７は、製造した結晶粒子の走査電子顕微鏡写真である。FIG. 7 is a scanning electron micrograph of the produced crystal particles. 図８は、製造した結晶粒子の電子線励起発光強度と波長の関係を示すグラフである。FIG. 8 is a graph showing the relationship between the electron beam excited luminescence intensity and the wavelength of the produced crystal particles. 図９は、製造した結晶粒子のＸ線回折測定を行った結果を示すグラフである。FIG. 9 is a graph showing the results of X-ray diffraction measurement of the produced crystal particles. 図１０は、製造した結晶粒子の走査電子顕微鏡写真である。FIG. 10 is a scanning electron micrograph of the produced crystal particles. 図１１は、比較例として、アルミニウム原料として蒸発させた金属アルミニウムを用い、この金属アルミニウムとＮ２若しくはＮＨ３ガスとを反応させることによって窒化アルミニウム結晶粒子を製造した場合における、反応室の温度とＸ線回折の半値全幅との関係を示すグラフである。FIG. 11 shows, as a comparative example, the temperature of the reaction chamber in the case where aluminum aluminum crystal particles were produced by reacting this metal aluminum with N 2 or NH 3 gas using evaporated aluminum as an aluminum raw material. It is a graph which shows the relationship with the full width at half maximum of X-ray diffraction. 図１２（ａ）は、金属アルミニウムとＮＨ３ガスとを反応させた場合におけるアルミニウム結晶粒子のＳＥＭ写真を示している。図１２（ｂ）は、金属アルミニウムとＮ２ガスとを反応させた場合におけるアルミニウム結晶粒子のＳＥＭ写真を示している。FIG. 12A shows an SEM photograph of aluminum crystal particles in the case where metallic aluminum and NH 3 gas are reacted. FIG. 12B shows an SEM photograph of aluminum crystal particles when metallic aluminum and N 2 gas are reacted. 図１３は、第２実施形態の方法に用いられる製造装置の構成を示す概略図である。FIG. 13 is a schematic diagram illustrating a configuration of a manufacturing apparatus used in the method of the second embodiment. 図１４は、反応室の温度分布の一例を示すグラフである。FIG. 14 is a graph showing an example of the temperature distribution in the reaction chamber. 図１５は、第７実施例において製造された窒化アルミニウム結晶粒子の試料番号と、各試料番号における反応室内の設定温度、塩化水素ガス流量、内管筒の有無、およびノズルの先端部の位置を基準とする内管筒の先端部の位置を示す図表である。FIG. 15 shows the sample numbers of the aluminum nitride crystal particles produced in the seventh example, the set temperature in the reaction chamber, the hydrogen chloride gas flow rate, the presence or absence of the inner tube, and the position of the tip of the nozzle for each sample number. It is a graph which shows the position of the front-end | tip part of the inner tube cylinder used as a reference | standard. 図１６は、内管筒の有無による窒化アルミニウム結晶粒子の結晶性への影響を示すグラフである。FIG. 16 is a graph showing the influence on the crystallinity of aluminum nitride crystal particles with and without the inner tube. 図１７は、内管筒が無い場合における窒化アルミニウム結晶粒子のＳＥＭ写真である。FIG. 17 is an SEM photograph of aluminum nitride crystal particles when there is no inner tube. 図１８は、内管筒が有る場合における窒化アルミニウム結晶粒子のＳＥＭ写真である。FIG. 18 is an SEM photograph of aluminum nitride crystal particles in the case where there is an inner tube. 図１９は、反応室内の設定温度による窒化アルミニウム結晶粒子の結晶性への影響を示すグラフである。FIG. 19 is a graph showing the influence of the set temperature in the reaction chamber on the crystallinity of the aluminum nitride crystal particles. 図２０（ａ）及び図２０（ｂ）それぞれは、試料＃１０１及び＃１０２それぞれにおける窒化アルミニウム結晶粒子のＳＥＭ写真である。20 (a) and 20 (b) are SEM photographs of aluminum nitride crystal grains in samples # 101 and # 102, respectively. 図２１（ａ）及び図２１（ｂ）それぞれは、試料＃１０３及び＃１０４それぞれにおける窒化アルミニウム結晶粒子のＳＥＭ写真である。FIG. 21A and FIG. 21B are SEM photographs of aluminum nitride crystal grains in Samples # 103 and # 104, respectively. 図２２（ａ）及び図２２（ｂ）それぞれは、試料＃１１１及び＃１１２それぞれにおける窒化アルミニウム結晶粒子のＳＥＭ写真である。FIGS. 22A and 22B are SEM photographs of aluminum nitride crystal grains in Samples # 111 and # 112, respectively. 図２３（ａ）は、試料＃１１５における窒化アルミニウム結晶粒子のＳＥＭ写真であり、図２３（ｂ）は図２３（ａ）を拡大したＳＥＭ写真であり、図２３（ｃ）は図２３（ｂ）を更に拡大したＳＥＭ写真である。FIG. 23 (a) is an SEM photograph of aluminum nitride crystal particles in sample # 115, FIG. 23 (b) is an enlarged SEM photograph of FIG. 23 (a), and FIG. It is the SEM photograph which expanded further. 図２４は、塩化水素ガス流量による窒化アルミニウム結晶粒子の結晶性への影響を示すグラフである。FIG. 24 is a graph showing the influence of the flow rate of hydrogen chloride gas on the crystallinity of aluminum nitride crystal particles. 図２５は試料＃１１３における窒化アルミニウム結晶粒子のＳＥＭ写真である。FIG. 25 is an SEM photograph of aluminum nitride crystal particles in Sample # 113. 図２６（ａ）は、試料＃１１６における窒化アルミニウム結晶粒子のＳＥＭ写真である。図２６（ｂ）は図２６（ａ）を拡大したＳＥＭ写真であり、図２６（ｃ）は図２６（ｂ）を更に拡大したＳＥＭ写真である。FIG. 26A is an SEM photograph of aluminum nitride crystal particles in Sample # 116. FIG. 26B is an enlarged SEM photograph of FIG. 26A, and FIG. 26C is an enlarged SEM photograph of FIG. 26B. 図２７は、試料＃１０８の走査型電子顕微鏡（ＳＥＭ）写真である。FIG. 27 is a scanning electron microscope (SEM) photograph of sample # 108. 図２８は、図２７の写真に含まれる個々の窒化アルミニウム結晶粒子を測定することにより求められた試料＃１０８の（ａ）粒径分布及び（ｂ）厚さ分布を示すヒストグラムである。FIG. 28 is a histogram showing (a) particle size distribution and (b) thickness distribution of sample # 108 obtained by measuring individual aluminum nitride crystal particles included in the photograph of FIG. 図２９は、試料＃１１２のＳＥＭ写真である。FIG. 29 is an SEM photograph of sample # 112. 図３０は、図２９の写真から求められた試料＃１１２の（ａ）粒径分布及び（ｂ）厚さ分布を示すヒストグラムである。FIG. 30 is a histogram showing (a) particle size distribution and (b) thickness distribution of sample # 112 obtained from the photograph of FIG. 図３１は、試料＃１１３のＳＥＭ写真である。FIG. 31 is an SEM photograph of sample # 113. 図３２は、図３１の写真から求められた試料＃１１３の（ａ）粒径分布及び（ｂ）厚さ分布を示すヒストグラムである。FIG. 32 is a histogram showing (a) particle size distribution and (b) thickness distribution of Sample # 113 obtained from the photograph of FIG. 図３３（ａ）及び図３３（ｂ）は、図３１に示された試料＃１１３のＳＥＭ写真のそれぞれ一部を拡大した写真である。FIG. 33A and FIG. 33B are photographs in which a part of each SEM photograph of the sample # 113 shown in FIG. 31 is enlarged. 図３４は、本実施例に係る試料＃１０４、＃１０８、＃１０９、＃１１０、＃１１１、＃１１２及び＃１１３のそれぞれにおける窒化アルミニウム結晶粒子の電子線励起発光（ＣＬ）の強度とその光の波長との関係を測定した結果である。FIG. 34 shows the intensity and light of electron beam excitation luminescence (CL) of aluminum nitride crystal particles in each of samples # 104, # 108, # 109, # 110, # 111, # 112, and # 113 according to this example. It is the result of having measured the relationship with the wavelength.
　以下、添付図面を参照しながら窒化アルミニウム結晶粒子の製造装置の実施の形態を詳細に説明する。なお、図面の説明において同一の要素には同一の符号を付し、重複する説明を省略する。
（第１の実施の形態） Hereinafter, embodiments of an apparatus for producing aluminum nitride crystal particles will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.
(First embodiment)
　まず、本方法に好適に用いられる窒化アルミニウム結晶粒子の製造装置の構成について説明する。図１は、本方法に用いられる製造装置１Ａの構成を示す概略図である。この製造装置１Ａは、気相法により結晶粒子を製造するための装置である。図１を参照すると、製造装置１Ａは、反応管２、加熱装置３、ガスライン４～６、シュラウド９及び排気管１２を備える。 First, the configuration of an apparatus for producing aluminum nitride crystal particles suitably used in the present method will be described. FIG. 1 is a schematic diagram showing the configuration of a manufacturing apparatus 1A used in this method. This manufacturing apparatus 1A is an apparatus for manufacturing crystal particles by a vapor phase method. Referring to FIG. 1, the production apparatus 1A includes a reaction tube 2, a heating device 3, gas lines 4 to 6, a shroud 9, and an exhaust pipe 12.
　反応管２は、第２の反応室２ａ、及び反応容器７を内部に有する。加熱装置３は、反応管２の高さ方向における一部の周囲に設置されている。加熱装置３としては、例えば電気管状炉が好適である。 The reaction tube 2 has a second reaction chamber 2a and a reaction vessel 7 inside. The heating device 3 is installed around a part of the reaction tube 2 in the height direction. For example, an electric tubular furnace is suitable as the heating device 3.
　ガスライン４は、アンモニアガスを反応室２ａへ供給するための管であり、反応管２の端面２ｂ寄りの壁面に設置されている。また、ガスライン５は、塩化水素ガスを反応容器７の内部へ供給するための管であり、反応管２の端面２ｂに設置されている。さらに、ガスライン６は、窒素ガスを反応室２ａへ供給するための管であり、反応管２の端面２ｂに設置されている。 The gas line 4 is a pipe for supplying ammonia gas to the reaction chamber 2a, and is installed on the wall surface near the end face 2b of the reaction pipe 2. The gas line 5 is a tube for supplying hydrogen chloride gas to the inside of the reaction vessel 7, and is installed on the end surface 2 b of the reaction tube 2. Further, the gas line 6 is a tube for supplying nitrogen gas to the reaction chamber 2 a and is installed on the end surface 2 b of the reaction tube 2.
　反応容器７の内部は第１の反応室７ａとなっている。反応室７ａは塩化アルミニウムガス（ＡｌＣｌ３）を発生させるための領域である。反応容器７は、加熱装置３の下端３ａよりもさらに端面２ｂ寄りに設置されている。反応容器７の端面２ｂ寄りの端面７ｂには、ガスライン５の先端部が接続されている。反応容器７の端面７ｂと対向する他の端面７ｃには、ノズル１０が接続されている。ノズル１０は、反応容器７の端面７ｃから反応室２ａまで延伸されている。反応室７ａには、原料８であるアルミニウムが設置されている。さらに、反応室７ａには、ガスライン５より熱電対１１が挿入され、熱電対１１の先端は、原料８の位置に設置されている。 The inside of the reaction vessel 7 is a first reaction chamber 7a. The reaction chamber 7a is an area for generating aluminum chloride gas (AlCl 3 ). The reaction vessel 7 is installed closer to the end surface 2 b than the lower end 3 a of the heating device 3. The front end of the gas line 5 is connected to the end surface 7 b near the end surface 2 b of the reaction vessel 7. A nozzle 10 is connected to the other end surface 7 c facing the end surface 7 b of the reaction vessel 7. The nozzle 10 extends from the end surface 7c of the reaction vessel 7 to the reaction chamber 2a. Aluminum which is the raw material 8 is installed in the reaction chamber 7a. Further, a thermocouple 11 is inserted into the reaction chamber 7 a from the gas line 5, and the tip of the thermocouple 11 is installed at the position of the raw material 8.
　シュラウド９は、反応管２の内部に配置され、端面２ｂから反応容器７とノズル１０の先端部との間の位置まで延伸されている。反応容器７はシュラウド９の内側に設置されている。また、ガスライン４から供給されるアンモニアガスは、反応管２の壁面とシュラウド９の間にある空隙を通過して、反応室２ａに導かれる。従って、反応室７ａで発生する塩化アルミニウムガスは、シュラウド９によりアンモニアガスから隔離されている。 The shroud 9 is disposed inside the reaction tube 2 and extends from the end surface 2 b to a position between the reaction vessel 7 and the tip of the nozzle 10. The reaction vessel 7 is installed inside the shroud 9. Further, the ammonia gas supplied from the gas line 4 passes through a gap between the wall surface of the reaction tube 2 and the shroud 9 and is guided to the reaction chamber 2a. Therefore, the aluminum chloride gas generated in the reaction chamber 7 a is isolated from the ammonia gas by the shroud 9.
　排気管１２は、反応室２ａにおいて反応の結果生じた残余ガスを排出するために、反応管２の端面２ｂと対向する他方の端面２ｃに設置されている。排気管１２の先端部には、繊維性フィルタ１３が設けられている。繊維性フィルタ１３は、反応の結果生じた窒化アルミニウム結晶粒子を捕集する。繊維性フィルタ１３としては、例えばシリカ繊維性フィルタ、ガラス繊維性フィルタが好適である。 The exhaust pipe 12 is installed on the other end face 2c facing the end face 2b of the reaction tube 2 in order to discharge the residual gas generated as a result of the reaction in the reaction chamber 2a. A fibrous filter 13 is provided at the tip of the exhaust pipe 12. The fibrous filter 13 collects aluminum nitride crystal particles generated as a result of the reaction. As the fiber filter 13, for example, a silica fiber filter or a glass fiber filter is suitable.
　図２は、反応室２ａの温度分布を示す一例である。図２の左側にあるグラフは、反応室２ａの高さ方向の温度分布を示している。Ａは加熱装置３の下端３ａの位置である。反応管２の高さ方向の距離はＡを座標原点としている。Ｂはノズル１０の先端部の位置であり、Ａからの距離は１８５ｍｍである。Ｃは加熱装置３の上端の位置であり、Ａからの距離は６２５ｍｍである。Ｄは繊維性フィルタ１３の位置であり、Ａからの距離は６９５ｍｍである。図２のグラフを参照すると、Ａからの距離が１５０ｍｍ以上４５０ｍｍ以下の領域で、約１４００℃（１３５０℃以上１４５０℃以下）の均一な温度分布が得られていることがわかる。また、ノズル１０の先端部は、約１４００℃の均一な温度分布が得られている領域内にあることがわかる。これにより、ノズル１０から供給される塩化アルミニウムガス及びガスライン４から供給されるアンモニアガスは、反応室２ａの約１４００℃（１３５０℃以上１４５０℃以下）の領域で反応することがわかる。 FIG. 2 is an example showing the temperature distribution in the reaction chamber 2a. The graph on the left side of FIG. 2 shows the temperature distribution in the height direction of the reaction chamber 2a. A is the position of the lower end 3 a of the heating device 3. The distance in the height direction of the reaction tube 2 is set to A as the coordinate origin. B is the position of the tip of the nozzle 10 and the distance from A is 185 mm. C is the position of the upper end of the heating device 3, and the distance from A is 625 mm. D is the position of the fibrous filter 13, and the distance from A is 695 mm. Referring to the graph of FIG. 2, it can be seen that a uniform temperature distribution of about 1400 ° C. (1350 ° C. to 1450 ° C.) is obtained in the region where the distance from A is 150 mm to 450 mm. It can also be seen that the tip of the nozzle 10 is in a region where a uniform temperature distribution of about 1400 ° C. is obtained. Thereby, it can be seen that the aluminum chloride gas supplied from the nozzle 10 and the ammonia gas supplied from the gas line 4 react in the region of about 1400 ° C. (1350 ° C. or higher and 1450 ° C. or lower) of the reaction chamber 2a.
　ここで、上記した製造装置１Ａを用いた窒化アルミニウム結晶粒子の製造方法について説明する。まず原料８として、アルミニウムを用意する。そして、このアルミニウムを反応室７ａに設置する。 Here, a manufacturing method of aluminum nitride crystal particles using the manufacturing apparatus 1A described above will be described. First, aluminum is prepared as the raw material 8. And this aluminum is installed in the reaction chamber 7a.
　続いて、反応室２ａへガスライン６から窒素ガスを供給する。そして、反応室２ａに窒素ガスの流れを形成しながら、加熱装置３によって反応室２ａの温度を例えば１３５０℃以上１４５０℃以下の範囲内に加熱する。また、これと並行して、反応室７ａに設置した原料８であるアルミニウムを、例えば５８０℃以上アルミニウムの融点以下の温度の範囲内（例えば６００℃）に加熱する。従って、アルミニウムは完全には溶解しない。このとき、反応室７ａに設置したアルミニウムの温度は、熱電対１１により計測される。アルミニウムの温度が５８０℃以上アルミニウムの融点以下の温度になるように、反応容器７と加熱装置３との距離が調整される。 Subsequently, nitrogen gas is supplied from the gas line 6 to the reaction chamber 2a. And while forming the flow of nitrogen gas in the reaction chamber 2a, the temperature of the reaction chamber 2a is heated within the range of 1350 ° C. or higher and 1450 ° C. or lower by the heating device 3, for example. In parallel with this, aluminum, which is the raw material 8 installed in the reaction chamber 7a, is heated within a temperature range of, for example, 580 ° C. or more and below the melting point of aluminum (eg 600 ° C.). Therefore, aluminum does not dissolve completely. At this time, the temperature of aluminum installed in the reaction chamber 7 a is measured by the thermocouple 11. The distance between the reaction vessel 7 and the heating device 3 is adjusted so that the temperature of aluminum is not lower than 580 ° C. and not higher than the melting point of aluminum.
　反応室２ａの温度が例えば１３５０℃以上１４５０℃以下の範囲内になった後、ガスライン５より塩化水素ガスを反応室７ａに供給する。これにより、アルミニウムと、塩化水素ガスとが反応し、塩化アルミニウムガスが発生する（Ａｌ＋３ＨＣｌ→ＡｌＣｌ３＋１．５Ｈ２）。また、発生した塩化アルミニウムガスは、シュラウド９によりアンモニアガスから隔離される。 After the temperature of the reaction chamber 2a falls within the range of, for example, 1350 ° C. or more and 1450 ° C. or less, hydrogen chloride gas is supplied from the gas line 5 to the reaction chamber 7a. As a result, aluminum and hydrogen chloride gas react to generate aluminum chloride gas (Al + 3HCl → AlCl 3 + 1.5H 2 ). The generated aluminum chloride gas is isolated from the ammonia gas by the shroud 9.
　続いて、ガスライン４よりアンモニアガスを反応室２ａへ供給する。これにより、アンモニアガスと、ノズル１０により導出された塩化アルミニウムガスとは、１３５０℃以上１４５０℃以下の範囲内の温度に加熱された反応室２ａにおいて反応し、窒化アルミニウム結晶粒子が製造される（ＡｌＣｌ３＋ＮＨ３→ＡｌＮ＋３ＨＣｌ）。製造された窒化アルミニウム結晶粒子は、繊維性フィルタ１３により捕集される。製造された窒化アルミニウム結晶粒子の粒径は、０．０５μｍ以上１μｍ以下の大きさである。なお、繊維性フィルタ１３の好適な温度範囲は、例えば４００℃以上８００℃以下である。 Subsequently, ammonia gas is supplied from the gas line 4 to the reaction chamber 2a. Thereby, the ammonia gas and the aluminum chloride gas led out by the nozzle 10 react in the reaction chamber 2a heated to a temperature in the range of 1350 ° C. or higher and 1450 ° C. or lower to produce aluminum nitride crystal particles ( AlCl 3 + NH 3 → AlN + 3HCl). The produced aluminum nitride crystal particles are collected by the fibrous filter 13. The produced aluminum nitride crystal particles have a particle size of 0.05 μm or more and 1 μm or less. In addition, the suitable temperature range of the fibrous filter 13 is 400 degreeC or more and 800 degrees C or less, for example.
　以上に説明した工程により、単結晶の窒化アルミニウム結晶粒子を製造することができる。 Through the steps described above, single crystal aluminum nitride crystal particles can be produced.
　本実施形態による窒化アルミニウム結晶粒子の製造装置では、窒化アルミニウム結晶粒子の製造に塩化アルミニウムが用いられる。従来、窒化アルミニウム結晶粒子の製造には蒸発させたアルミニウムが用いられていたが、この方法では単結晶の窒化アルミニウム結晶粒子を得ることが困難であった。また、アルミニウムの温度を融点以下にすることにより、石英ガラスを腐蝕させるＡｌＣｌ（アルミニウム塩化物）の生成を抑制することができる。従って、本実施形態による製造装置によれば、単結晶の窒化アルミニウム結晶粒子を高い割合で含む粉末を製造することが可能となるため、単結晶の窒化アルミニウム結晶粒子を効率よく製造することができる。 In the apparatus for producing aluminum nitride crystal particles according to the present embodiment, aluminum chloride is used for producing aluminum nitride crystal particles. Conventionally, evaporated aluminum is used for the production of aluminum nitride crystal particles, but it has been difficult to obtain single crystal aluminum nitride crystal particles by this method. Moreover, the production | generation of AlCl (aluminum chloride) which corrodes quartz glass can be suppressed by making the temperature of aluminum below melting | fusing point. Therefore, according to the manufacturing apparatus according to the present embodiment, it is possible to manufacture a powder containing a single crystal aluminum nitride crystal particle at a high ratio, and therefore it is possible to efficiently manufacture single crystal aluminum nitride crystal particles. .
　また、本実施形態による窒化アルミニウム結晶粒子の製造装置は気相法を用いた装置であるため、連続合成が可能であり、量産への応用が容易にできる。さらに、本実施形態では、シュラウド９により、第１の反応室７ａに設置されたアルミニウムが融点以上の温度に加熱されることを防ぐことができる。 Further, since the apparatus for producing aluminum nitride crystal particles according to the present embodiment is an apparatus using a vapor phase method, it can be continuously synthesized and can be easily applied to mass production. Furthermore, in this embodiment, the shroud 9 can prevent the aluminum installed in the first reaction chamber 7a from being heated to a temperature equal to or higher than the melting point.
　本実施形態では、繊維性フィルタ１３により効率的に窒化アルミニウム結晶粒子を捕集することができる。また、本実施形態では、塩化アルミニウムガス及びアンモニアガスを１３５０℃以上１４５０℃以下の範囲内で反応させることにより、製造された窒化アルミニウム結晶粒子の粒径を均一にすることができる。 In this embodiment, the aluminum nitride crystal particles can be efficiently collected by the fibrous filter 13. Moreover, in this embodiment, the particle diameter of the manufactured aluminum nitride crystal particle can be made uniform by making aluminum chloride gas and ammonia gas react within the range of 1350 degreeC or more and 1450 degrees C or less.
　本実施形態による窒化アルミニウム結晶粒子の製造方法では、窒化アルミニウム結晶粒子の製造に塩化アルミニウムを用いる。従来は、窒化アルミニウム結晶粒子の製造に蒸発させたアルミニウムが用いられていたが、この方法では単結晶の窒化アルミニウム結晶粒子を得ることが困難であった。また、アルミニウムの温度を融点以下にすることにより、石英ガラスを腐蝕させるＡｌＣｌ（アルミニウム塩化物）の生成を抑制することができる。従って、本実施形態による製造方法によれば、単結晶の窒化アルミニウム結晶粒子を高い割合で含む粉末を製造することが可能となるため、単結晶の窒化アルミニウム結晶粒子を効率よく製造することができる。 In the method for producing aluminum nitride crystal particles according to the present embodiment, aluminum chloride is used for producing the aluminum nitride crystal particles. Conventionally, evaporated aluminum is used for producing aluminum nitride crystal particles, but it is difficult to obtain single crystal aluminum nitride crystal particles by this method. Moreover, the production | generation of AlCl (aluminum chloride) which corrodes quartz glass can be suppressed by making the temperature of aluminum below melting | fusing point. Therefore, according to the manufacturing method according to the present embodiment, it is possible to manufacture a powder containing a single crystal aluminum nitride crystal particle at a high ratio, and therefore it is possible to efficiently manufacture single crystal aluminum nitride crystal particles. .
　また、本実施形態による窒化アルミニウム結晶粒子の製造方法は気相法であるため、連続合成が可能であり、量産への応用が容易にできる。さらに、本実施形態では、シュラウド９により、第１の反応室７ａに設置されたアルミニウムが融点以上の温度に加熱されることを防ぐことができる。 Further, since the method for producing aluminum nitride crystal particles according to the present embodiment is a vapor phase method, continuous synthesis is possible, and application to mass production can be easily performed. Furthermore, in this embodiment, the shroud 9 can prevent the aluminum installed in the first reaction chamber 7a from being heated to a temperature equal to or higher than the melting point.
　本実施形態では、繊維性フィルタ１３により効率的に窒化アルミニウム結晶粒子を捕集することができる。また、本実施形態では、塩化アルミニウムガス及びアンモニアガスを１３５０℃以上１４５０℃以下の範囲内で反応させることにより、製造された窒化アルミニウム結晶粒子の粒径を均一にすることができる。 In this embodiment, the aluminum nitride crystal particles can be efficiently collected by the fibrous filter 13. Moreover, in this embodiment, the particle diameter of the manufactured aluminum nitride crystal particle can be made uniform by making aluminum chloride gas and ammonia gas react within the range of 1350 degreeC or more and 1450 degrees C or less.
　上記した窒化アルミニウム結晶粒子は、反応室７ａがシュラウド９によりアンモニアガスから隔離されている状態で製造される。これにより、反応室２ａの温度が例えば１３５０℃以上の高温になる場合であっても、反応室７ａに設置されたアルミニウムが融点以上の温度に加熱されることを防いだ状態で製造されることができる。また、上記した本実施形態による窒化アルミニウム結晶粒子は、従来の多結晶の窒化アルミニウム結晶粒子では不可能であった大型窒化アルミニウム結晶育成用の種結晶として利用することができる。大型窒化アルミニウム単結晶は、ＧａＮ系発光及び電子デバイスのエピタキシャル成長基板として利用することができる。また、結晶性の優れた単結晶の窒化アルミニウム結晶粒子を使用することにより、従来の多結晶の窒化アルミニウム結晶粒子では困難であった、窒化アルミニウムを母体とする蛍光体の大幅な高効率化を図ることができる。 The aluminum nitride crystal particles described above are produced in a state where the reaction chamber 7a is isolated from the ammonia gas by the shroud 9. Thereby, even when the temperature of the reaction chamber 2a becomes a high temperature of, for example, 1350 ° C. or higher, the aluminum installed in the reaction chamber 7a is manufactured in a state in which it is prevented from being heated to a temperature higher than the melting point. Can do. In addition, the aluminum nitride crystal particles according to the present embodiment described above can be used as a seed crystal for growing a large aluminum nitride crystal, which was impossible with conventional polycrystalline aluminum nitride crystal particles. The large aluminum nitride single crystal can be used as an epitaxial growth substrate for GaN-based light emitting and electronic devices. In addition, by using single crystal aluminum nitride crystal particles with excellent crystallinity, it has been difficult to achieve high efficiency of phosphors based on aluminum nitride, which was difficult with conventional polycrystalline aluminum nitride crystal particles. Can be planned.
　（実施例１）
反応管２として内径６０ｍｍ、高さ１０００ｍｍである高純度アルミナ製縦型反応管と、加熱装置３として加熱部の長さが５００ｍｍである電気管状炉とを含む製造装置１Ａを準備した。反応管２は、重力加速度の方向と反応管２の高さ方向とが互いに沿うように設置され、窒素ガス、塩化水素ガス及びアンモニアガスは、端面２ｂ寄りに設置されたガスライン４～６から供給され、反応の結果生じたガスは、端面２ｃ寄りに設置された排気管１２より排気される。使用する原料８は金属アルミニウムである。使用するガスは２０％窒素希釈の塩化水素ガス、アンモニアガス及び窒素ガスである。 Example 1
A manufacturing apparatus 1A including a high-purity alumina vertical reaction tube having an inner diameter of 60 mm and a height of 1000 mm as the reaction tube 2 and an electric tubular furnace having a heating unit length of 500 mm was prepared as the heating device 3. The reaction tube 2 is installed so that the direction of acceleration of gravity and the height direction of the reaction tube 2 are along each other, and nitrogen gas, hydrogen chloride gas, and ammonia gas are supplied from the gas lines 4 to 6 installed near the end surface 2b. The gas that is supplied and generated as a result of the reaction is exhausted from the exhaust pipe 12 installed near the end face 2c. The raw material 8 used is metallic aluminum. The gases used are 20% nitrogen diluted hydrogen chloride gas, ammonia gas and nitrogen gas.
　本実施例では、反応室２ａの温度と、窒素ガス、塩化水素ガス及びアンモニアガスの流量とを変数とし、それぞれ異なる３つの条件を設定して、試料ａ、ｂ及びｃを製造した。図３は、それぞれ異なる３つの条件と試料ａ、ｂ及びｃとの対応を示す表である。ここで、ガス流量の単位は、１分間あたりの標準状態での体積を立方センチメートルで表記した場合のガス流量である。 In this example, samples a, b, and c were manufactured by setting three different conditions using the temperature of the reaction chamber 2a and the flow rates of nitrogen gas, hydrogen chloride gas, and ammonia gas as variables. FIG. 3 is a table showing correspondence between three different conditions and samples a, b, and c. Here, the unit of the gas flow rate is the gas flow rate when the volume in the standard state per minute is expressed in cubic centimeters.
　次に、例えば試料ａの製造工程を説明する。まず、ガスライン６から窒素ガスを１７３０ｓｃｃｍの流量で反応室２ａに供給し、反応室２ａに窒素ガスの流れを形成しつつ、反応室２ａの温度が１４５０℃になるように加熱する。これと並行して、反応室７ａに設置した金属アルミニウムの温度が約６００℃になるように加熱する。反応室２ａの温度が一定になった後、反応管２の端面２ｂに設置されたガスライン５から、２０％窒素ガス希釈の塩化水素ガスを２０ｓｃｃｍの流量で反応室７ａへ供給し、塩化水素ガスと金属アルミニウムとを反応させることにより、塩化アルミニウムガスを発生させる（Ａｌ＋３ＨＣｌ→ＡｌＣｌ３＋１．５Ｈ２）。 Next, for example, a manufacturing process of the sample a will be described. First, nitrogen gas is supplied from the gas line 6 to the reaction chamber 2a at a flow rate of 1730 sccm, and the temperature of the reaction chamber 2a is heated to 1450 ° C. while forming a flow of nitrogen gas in the reaction chamber 2a. In parallel with this, heating is performed so that the temperature of the metal aluminum installed in the reaction chamber 7a is about 600 ° C. After the temperature of the reaction chamber 2a becomes constant, hydrogen chloride gas diluted with 20% nitrogen gas is supplied from the gas line 5 installed on the end face 2b of the reaction tube 2 to the reaction chamber 7a at a flow rate of 20 sccm. By reacting the gas with metallic aluminum, aluminum chloride gas is generated (Al + 3HCl → AlCl 3 + 1.5H 2 ).
　続いて、ガスライン４からアンモニアガスを２５０ｓｃｃｍの流量で反応室２ａに供給し、アンモニアガスと塩化アルミニウムガスとを、反応室２ａの１４５０℃の領域で反応させ、窒化アルミニウム結晶粒子を製造する（ＡｌＣｌ３＋ＮＨ３→ＡｌＮ＋３ＨＣｌ）。窒化アルミニウム結晶粒子は、ガラス繊維性フィルタ１３により捕集される。 Subsequently, ammonia gas is supplied from the gas line 4 to the reaction chamber 2a at a flow rate of 250 sccm, and ammonia gas and aluminum chloride gas are reacted in the 1450 ° C. region of the reaction chamber 2a to produce aluminum nitride crystal particles ( AlCl 3 + NH 3 → AlN + 3HCl). Aluminum nitride crystal particles are collected by the glass fiber filter 13.
　図４は、製造した試料ａ、ｂ及びｃについて、Ｘ線回折測定（ＸＲＤ法）を行った結果である。図４を参照すると、試料ａ、ｂ及びｃは、全て窒化アルミニウム結晶粒子のみで構成されていることがわかる。 FIG. 4 shows the results of X-ray diffraction measurement (XRD method) for the manufactured samples a, b, and c. Referring to FIG. 4, it can be seen that samples a, b, and c are all composed only of aluminum nitride crystal particles.
　図５は、図３のａ、ｂ及びｃの条件で製造した窒化アルミニウム結晶粒子の走査電子顕微鏡写真である。図５において（ａ）は試料ａの写真であり、（ｂ）は試料ｂの写真であり、（ｃ）は試料ｃの写真である。図５を参照すると、ほとんどの粒子は、ウルツ鉱構造を反映した６回対称の各々独立した六角柱又は六角鼓形であり、単結晶の窒化アルミニウム結晶粒子が高い割合で製造されていることがわかる。ここで、六角鼓形の形状とは、六角形の端面に挟まれる領域の断面形状が六角形であり、該六角形が端面の六角形よりも小さい形状である立体形状をいう。また、窒化アルミニウム結晶粒子の粒径は、およそ０．０５μｍ以上０．８μｍ以下であることがわかる。 FIG. 5 is a scanning electron micrograph of aluminum nitride crystal particles produced under the conditions of a, b and c in FIG. In FIG. 5, (a) is a photograph of sample a, (b) is a photograph of sample b, and (c) is a photograph of sample c. Referring to FIG. 5, most of the particles are six-fold symmetrical hexagonal cylinders or hexagonal drums reflecting the wurtzite structure, and a high proportion of single crystal aluminum nitride crystal particles are produced. Recognize. Here, the hexagonal drum shape refers to a three-dimensional shape in which the cross-sectional shape of the region sandwiched between the hexagonal end faces is a hexagon, and the hexagon is smaller than the hexagon on the end face. Moreover, it turns out that the particle size of an aluminum nitride crystal grain is about 0.05 micrometer or more and 0.8 micrometer or less.
　図６は、比較例として、市販の窒化アルミニウム結晶粒子の走査電子顕微鏡写真を示している。図５と図６との比較から明らかなように、本実施例により製造される窒化アルミニウム結晶粒子は、従来のものと比較して結晶性が極めて高い（単結晶の）粒子であることがわかる。 FIG. 6 shows a scanning electron micrograph of commercially available aluminum nitride crystal particles as a comparative example. As is clear from the comparison between FIG. 5 and FIG. 6, it can be seen that the aluminum nitride crystal particles produced by this example are particles having a very high crystallinity (single crystal) as compared with the conventional one. .
　（実施例２）
実施例１に示した条件と異なる条件で、窒化アルミニウム結晶粒子を製造した。まず、実施例１と同様の製造装置１Ａを準備した。使用する原料８は金属アルミニウムである。使用するガスは２０％窒素希釈の塩化水素ガス、アンモニアガス及び窒素ガスである。 (Example 2)
Aluminum nitride crystal particles were produced under conditions different from those shown in Example 1. First, the manufacturing apparatus 1A similar to Example 1 was prepared. The raw material 8 used is metallic aluminum. The gases used are 20% nitrogen diluted hydrogen chloride gas, ammonia gas and nitrogen gas.
　次に、製造工程を説明する。まず、ガスライン６から窒素ガス（流量９８０ｓｃｃｍ～１７８０ｓｃｃｍ）を反応室２ａに供給し、反応室２ａに窒素ガスの流れを形成しつつ、反応室２ａの温度が１４５０℃になるように加熱する。これと並行して、金属アルミニウムの温度が約６００℃になるように加熱する。反応室２ａの温度が一定になった後、反応管２の端面２ｂに設置されたガスライン５から、４ｓｃｃｍの流量である塩化水素ガスと１６ｓｃｃｍの流量である窒素ガスとを混合したガスを反応室７ａへ供給し、塩化水素ガスと金属アルミニウムとを反応させることにより、塩化アルミニウムガスを発生させる（Ａｌ＋３ＨＣｌ→ＡｌＣｌ３＋１．５Ｈ２）。 Next, the manufacturing process will be described. First, nitrogen gas (flow rate: 980 sccm to 1780 sccm) is supplied from the gas line 6 to the reaction chamber 2a, and while the nitrogen gas flow is formed in the reaction chamber 2a, the temperature of the reaction chamber 2a is heated to 1450 ° C. In parallel with this, heating is performed so that the temperature of the metallic aluminum is about 600 ° C. After the temperature of the reaction chamber 2a becomes constant, a gas mixed with hydrogen chloride gas having a flow rate of 4 sccm and nitrogen gas having a flow rate of 16 sccm is reacted from the gas line 5 installed on the end surface 2b of the reaction tube 2. It supplies to the chamber 7a, and hydrogen chloride gas and metal aluminum are reacted to generate aluminum chloride gas (Al + 3HCl → AlCl 3 + 1.5H 2 ).
　続いて、ガスライン４からアンモニアガスと窒素ガスとを混合したガスを反応室２ａに供給する。混合したガスのうち、アンモニアガスの流量は２５０ｓｃｃｍ以上１０００ｓｃｃｍ以下であり、窒素ガスの流量は例えば０ｓｃｃｍである。アンモニアガスと塩化アルミニウムガスとを反応室２ａで反応させ、窒化アルミニウム結晶粒子を製造する（ＡｌＣｌ３＋ＮＨ３→ＡｌＮ＋３ＨＣｌ）。製造された粒子は、シリカ繊維性フィルタ１３により捕集される。なお、ガスライン４及び６から供給される窒素ガスの流量は、合わせて９８０ｓｃｃｍ以上１７３０ｓｃｃｍ以下である。 Subsequently, a gas obtained by mixing ammonia gas and nitrogen gas is supplied from the gas line 4 to the reaction chamber 2a. Among the mixed gases, the flow rate of ammonia gas is 250 sccm or more and 1000 sccm or less, and the flow rate of nitrogen gas is, for example, 0 sccm. Ammonia gas and aluminum chloride gas are reacted in the reaction chamber 2a to produce aluminum nitride crystal particles (AlCl 3 + NH 3 → AlN + 3HCl). The produced particles are collected by the silica fibrous filter 13. The flow rate of nitrogen gas supplied from the gas lines 4 and 6 is 980 sccm or more and 1730 sccm or less in total.
　上記した条件で製造した窒化アルミニウム結晶粒子の特徴を確認した結果、窒化アルミニウム結晶粒子は単結晶でウルツ鉱構造の六角柱型及び六角鼓形を有していた。また、粒子の大きさは０．０５μｍ以上０．８μｍ以下であった。最も大きな粒子は直径及び長さが約０．８μｍであり、粒子の平均長さは約０．３μｍであった。 As a result of confirming the characteristics of the aluminum nitride crystal particles produced under the above conditions, the aluminum nitride crystal particles were a single crystal and had a wurtzite hexagonal prism shape and hexagonal drum shape. The particle size was 0.05 μm or more and 0.8 μm or less. The largest particles were about 0.8 μm in diameter and length, and the average length of the particles was about 0.3 μm.
　（実施例３）
図７は、反応室２ａの温度を１４００℃として製造した窒化アルミニウム結晶粒子の走査電子顕微鏡写真である。なお、本実施例では、ガスライン６から供給される窒素ガスの流量を５００ｓｃｃｍとし、ガスライン５から供給される塩化水素ガスの流量を４ｓｃｃｍ（希釈用窒素ガスとの総和では２０ｓｃｃｍ）とし、ガスライン４から供給されるアンモニアガス及び窒素ガスの各流量をそれぞれ１０００ｓｃｃｍ、４８０ｓｃｃｍとした。図７を参照すると、粒子Ａは、完全な単結晶粒子であり、粒子Ｂは、ｃ軸の向きが真逆の２つの単結晶グレインが結合した粒子である可能性があることがわかる。また、図７を参照すると、粒子Ａのうち、面Ｃ及び面Ｄは一方が（０００１）Ａｌ面であり他の一方が（０００１）Ｎ面であることがわかる。結晶方位は、透過型電子顕微鏡（ＴＥＭ）により測定される回折スポット形状を解析することで確定できる。 (Example 3)
FIG. 7 is a scanning electron micrograph of aluminum nitride crystal particles produced at a reaction chamber 2a temperature of 1400 ° C. In this embodiment, the flow rate of the nitrogen gas supplied from the gas line 6 is 500 sccm, the flow rate of the hydrogen chloride gas supplied from the gas line 5 is 4 sccm (20 sccm in total with the dilution nitrogen gas), and the gas The flow rates of ammonia gas and nitrogen gas supplied from the line 4 were 1000 sccm and 480 sccm, respectively. Referring to FIG. 7, it can be seen that the particle A is a complete single crystal particle, and the particle B may be a particle in which two single crystal grains whose c-axis directions are exactly opposite are combined. In addition, referring to FIG. 7, it can be seen that among the particles A, one of the surface C and the surface D is a (0001) Al surface and the other is a (0001) N surface. The crystal orientation can be determined by analyzing the diffraction spot shape measured by a transmission electron microscope (TEM).
　（実施例４）
図８は、反応室２ａの温度を１５００℃として製造した窒化アルミニウム結晶粒子の電子線励起発光（Cathodo Luminescence）の強度とその光の波長との関係を測定した結果である。図８を参照すると、最大発光強度の波長は、約３７５ｎｍであることがわかる。この波長は、製造条件により多少変動する。なお、本実施例では、ガスライン６から供給される窒素ガスの流量を５００ｓｃｃｍとし、ガスライン５から供給される塩化水素ガスの流量を４ｓｃｃｍ（希釈用窒素ガスとの総和では２０ｓｃｃｍ）とし、ガスライン４から供給されるアンモニアガス及び窒素ガスの各流量をそれぞれ１０００ｓｃｃｍ、４８０ｓｃｃｍとした。 Example 4
FIG. 8 shows the results of measuring the relationship between the intensity of electron beam excited luminescence (Cathodo Luminescence) of the aluminum nitride crystal particles produced at a reaction chamber 2a temperature of 1500 ° C. and the wavelength of the light. Referring to FIG. 8, it can be seen that the wavelength of the maximum emission intensity is about 375 nm. This wavelength varies somewhat depending on the manufacturing conditions. In this embodiment, the flow rate of the nitrogen gas supplied from the gas line 6 is 500 sccm, the flow rate of the hydrogen chloride gas supplied from the gas line 5 is 4 sccm (20 sccm in total with the dilution nitrogen gas), and the gas The flow rates of ammonia gas and nitrogen gas supplied from the line 4 were 1000 sccm and 480 sccm, respectively.
　（実施例５）
アンモニアガスの分圧が窒化アルミニウム結晶粒子の形成に与える影響を調べるために、次の実験を行った。まず、実施例１と同様な製造装置１Ａを準備した。反応室７ａに金属アルミニウムを設置し、金属アルミニウムが約６００℃になるまで加熱した。その後、塩化水素ガスを４ｓｃｃｍの流量で反応室７ａに供給し、塩化アルミニウムガスを生成させた。続いて、反応室２ａの温度が１４５０℃になるまで加熱し、塩化アルミニウムガスとガスライン４から供給したアンモニアガスとを反応させて、窒化アルミニウム結晶粒子を製造した。本実施例５では、アンモニアガスの流量と、アンモニアガスの分圧を変化させた。ここで、アンモニアガスの分圧は、アンモニアガスに窒素ガスを混合することにより変化させた。 (Example 5)
In order to investigate the influence of the partial pressure of ammonia gas on the formation of aluminum nitride crystal grains, the following experiment was conducted. First, the manufacturing apparatus 1A similar to Example 1 was prepared. Metal aluminum was placed in the reaction chamber 7a and heated until the metal aluminum reached about 600 ° C. Thereafter, hydrogen chloride gas was supplied to the reaction chamber 7a at a flow rate of 4 sccm to generate aluminum chloride gas. Then, it heated until the temperature of the reaction chamber 2a became 1450 degreeC, the aluminum chloride gas and the ammonia gas supplied from the gas line 4 were made to react, and the aluminum nitride crystal particle was manufactured. In Example 5, the flow rate of ammonia gas and the partial pressure of ammonia gas were changed. Here, the partial pressure of ammonia gas was changed by mixing nitrogen gas with ammonia gas.
　図９は、異なる分圧条件で製造した窒化アルミニウム結晶粒子について、Ｘ線回折測定を行った結果である。図９において、グラフＧａはアンモニアの分圧が０．２５ａｔｍである場合を示し、グラフＧｂはアンモニアの分圧が０．１２５ａｔｍである場合を示している。図９を参照すると、異なる分圧条件であっても、製造される粒子は、窒化アルミニウム結晶粒子のみであることがわかる。図１０は、異なる分圧条件で製造された窒化アルミニウム結晶粒子の電子顕微鏡写真である。図１０（ａ）は、アンモニアの分圧が０．１２５ａｔｍである場合の写真であり、図１０（ｂ）はアンモニアの分圧が０．２５ａｔｍである場合の写真である。図１０を参照すると、製造された結晶粒子は、ウルツ鉱構造を反映した６回対称の形状をもつ単結晶粒子が多いことがわかる。また、図１０（ａ）と図１０（ｂ）とを比較すると、アンモニアガスの分圧の減少に従い粒径が増大する傾向があることがわかった。これは、微小な核の生成に比べて、粒子の成長が促進されたためと考えられる。 FIG. 9 shows the results of X-ray diffraction measurement of aluminum nitride crystal particles produced under different partial pressure conditions. In FIG. 9, graph Ga shows the case where the partial pressure of ammonia is 0.25 atm, and graph Gb shows the case where the partial pressure of ammonia is 0.125 atm. Referring to FIG. 9, it can be seen that the produced particles are only aluminum nitride crystal particles even under different partial pressure conditions. FIG. 10 is an electron micrograph of aluminum nitride crystal particles produced under different partial pressure conditions. FIG. 10A is a photograph when the partial pressure of ammonia is 0.125 atm, and FIG. 10B is a photograph when the partial pressure of ammonia is 0.25 atm. Referring to FIG. 10, it can be seen that the produced crystal particles are many single crystal particles having a 6-fold symmetrical shape reflecting the wurtzite structure. Further, comparing FIG. 10A and FIG. 10B, it was found that the particle size tends to increase as the partial pressure of ammonia gas decreases. This is thought to be because the growth of particles was promoted compared to the generation of minute nuclei.
　なお、本実施例では、ガスライン６から供給される窒素ガスの流量を１４８０ｓｃｃｍとし、ガスライン５から供給される塩化水素ガスの流量を４ｓｃｃｍ（希釈用窒素ガスとの総和では２０ｓｃｃｍ）とし、ガスライン４から供給されるアンモニアガス及び窒素ガスの各流量をそれぞれ５００ｓｃｃｍ、０ｓｃｃｍ（アンモニアの分圧が０．２５０ａｔｍである場合）或いはそれぞれ２５０ｓｃｃｍ、２５０ｓｃｃｍ（アンモニアの分圧が０．１２５ａｔｍである場合）とした。 In the present embodiment, the flow rate of nitrogen gas supplied from the gas line 6 is 1480 sccm, the flow rate of hydrogen chloride gas supplied from the gas line 5 is 4 sccm (20 sccm in total with the nitrogen gas for dilution), and the gas The flow rates of ammonia gas and nitrogen gas supplied from line 4 are 500 sccm and 0 sccm, respectively (when the partial pressure of ammonia is 0.250 atm), or 250 sccm and 250 sccm, respectively (when the partial pressure of ammonia is 0.125 atm) It was.
　上記した結果より、塩化アルミニウムは単結晶の窒化アルミニウム結晶粒子を製造するための材料として適していることがわかった。 From the above results, it was found that aluminum chloride is suitable as a material for producing single crystal aluminum nitride crystal particles.
　（実施例６）
ここで、図１１は、比較例として、アルミニウム原料として蒸発させた金属アルミニウムを用い、この金属アルミニウムとＮ２若しくはＮＨ３ガスとを反応させることによって窒化アルミニウム結晶粒子を製造した場合における、反応室２ａの温度と（１００）Ｘ線回折の半値全幅（ＦＷＨＭ、単位：度）との関係を示すグラフである。また、図１２（ａ）は、金属アルミニウムとＮＨ３ガスとを反応させた場合におけるアルミニウム結晶粒子の走査電子顕微鏡（ＳＥＭ）写真を示しており、図１２（ｂ）は、金属アルミニウムとＮ２ガスとを反応させた場合におけるアルミニウム結晶粒子のＳＥＭ写真を示している。図１１及び図１２に示されるように、金属アルミニウムとＮ２若しくはＮＨ３とを直接反応させた場合、第１実施形態のようにＡｌＣｌ３とＮＨ３とを反応させた場合と比較して、結晶性は同等であるが、単結晶粒子の割合は極めて低い。
（第２の実施の形態） (Example 6)
Here, FIG. 11 shows, as a comparative example, a reaction chamber in the case where aluminum nitride crystal particles are produced by reacting evaporated metal aluminum as an aluminum raw material and reacting this metal aluminum with N 2 or NH 3 gas. It is a graph which shows the relationship between the temperature of 2a, and the full width at half maximum (FWHM, unit: degree) of (100) X-ray diffraction. FIG. 12A shows a scanning electron microscope (SEM) photograph of aluminum crystal particles in the case of reacting metallic aluminum with NH 3 gas, and FIG. 12B shows metallic aluminum and N 2. The SEM photograph of the aluminum crystal particle at the time of making it react with gas is shown. As shown in FIGS. 11 and 12, when the metal aluminum is directly reacted with N 2 or NH 3 , as compared with the case where AlCl 3 is reacted with NH 3 as in the first embodiment, Although the crystallinity is equivalent, the proportion of single crystal particles is very low.
(Second Embodiment)
　図１３は、本方法に用いられる製造装置１Ｂの構成を示す概略図である。この製造装置１Ｂは、気相法により結晶粒子を製造するための装置である。第１実施形態の製造装置１Ａと本実施形態の製造装置１Ｂとの相違点は、シュラウドの形状である。すなわち、本実施形態のシュラウド１９は、本体部１９ａと、内管筒１９ｂとを有する。本体部１９ａは、反応管２の長手方向に延びる円筒状の部材である。本体部１９ａは、反応管２の内部に配置され、反応管２の底面から反応容器７とノズル１０の先端部との間の位置まで延伸されている。反応容器７は、本体部１９ａの内側に設置されている。内管筒１９ｂは、反応管２の長手方向に延びる円筒状の部材であって、本体部１９ａにおける反応容器７とノズル１０の先端部との間の位置から、ノズル１０の先端部の位置付近まで延伸されている。反応管２の長手方向における内管筒１９ｂの先端部の位置は、ノズル１０の先端部の位置よりも反応室２ａ側に配置されてもよく、また、ノズル１０の先端部の位置よりも本体部１９ａ側に配置されてもよく、また、ノズル１０の先端部の位置と等しくてもよい。 FIG. 13 is a schematic diagram showing the configuration of the manufacturing apparatus 1B used in the present method. This manufacturing apparatus 1B is an apparatus for manufacturing crystal particles by a vapor phase method. The difference between the manufacturing apparatus 1A of the first embodiment and the manufacturing apparatus 1B of the present embodiment is the shape of the shroud. That is, the shroud 19 of this embodiment has a main body 19a and an inner tube 19b. The main body 19 a is a cylindrical member that extends in the longitudinal direction of the reaction tube 2. The main body portion 19 a is disposed inside the reaction tube 2 and extends from the bottom surface of the reaction tube 2 to a position between the reaction vessel 7 and the tip of the nozzle 10. The reaction vessel 7 is installed inside the main body 19a. The inner tube 19b is a cylindrical member extending in the longitudinal direction of the reaction tube 2, and is located near the position of the tip of the nozzle 10 from the position between the reaction vessel 7 and the tip of the nozzle 10 in the main body 19a. Has been stretched to The position of the distal end portion of the inner tube cylinder 19b in the longitudinal direction of the reaction tube 2 may be arranged closer to the reaction chamber 2a than the position of the distal end portion of the nozzle 10, and the main body is located more than the position of the distal end portion of the nozzle 10. It may be arranged on the part 19a side, and may be equal to the position of the tip of the nozzle 10.
　ガスライン４から供給されるアンモニアガスは、反応管２の壁面とシュラウド１９との間にある空隙を通過して、反応室２ａに導かれる。従って、アンモニアガスは、反応室２ａに到達するまで、反応室７ａにて溶解していないアルミニウムと塩化水素ガスの塩素が化合し、気相中ではアルミニウムと塩素の化学量論的に、Ａｌ：Ｃｌが１：１から１：３までの結合状態となって発生する塩化アルミニウムガス（以下では「三塩化アルミニウムガス」という。）、及びガスライン６から導入される窒素ガスから隔離される。 The ammonia gas supplied from the gas line 4 passes through the space between the wall surface of the reaction tube 2 and the shroud 19 and is guided to the reaction chamber 2a. Therefore, until the ammonia gas reaches the reaction chamber 2a, the aluminum not dissolved in the reaction chamber 7a and the chlorine of the hydrogen chloride gas are combined, and in the gas phase, the stoichiometry of aluminum and chlorine is Al: It is isolated from aluminum chloride gas (hereinafter referred to as “aluminum trichloride gas”) generated in a combined state of Cl from 1: 1 to 1: 3 and nitrogen gas introduced from the gas line 6.
　図１４は、反応室２ａの温度分布の一例を示すグラフである。図１４において、縦軸は反応管２の長手方向における位置を示しており、加熱装置３の下端３ａの位置（Ａ）を原点としている。横軸は温度を示している。なお、図中のＢは、ノズル１０の先端部の位置であり、Ａからの距離は例えば１８５ｍｍである。Ｃは、加熱装置３の上端の位置であり、Ａからの距離は例えば６２０ｍｍである。Ｄは、繊維性フィルタ１３の位置であり、Ａからの距離は例えば６９５ｍｍである。Ｅは、反応管２の上端の位置であり、Ａからの距離は例えば１０００ｍｍである。図１４を参照すると、少なくともＡからの距離が１５０ｍｍ以上４５０ｍｍ以下の領域において、各設定温度（１３００℃、１４００℃、１５００℃）の均一な温度分布が得られていることがわかる。特に、設定温度が１４００℃の場合、該領域における温度分布は１３５０℃以上１４５０℃以下の範囲に収まっている。また、ノズル１０の先端部およびシュラウド１９の先端部は、各設定温度の均一な温度分布が得られている領域内にあることがわかる。したがって、ノズル１０から供給される三塩化アルミニウムガスとガスライン４から供給されるアンモニアガスとは、反応室２ａの均一な温度分布の領域（例えば、設定温度が１４００℃である場合には１３５０℃以上１４５０℃以下の領域）において互いに反応することができる。 FIG. 14 is a graph showing an example of the temperature distribution in the reaction chamber 2a. In FIG. 14, the vertical axis indicates the position in the longitudinal direction of the reaction tube 2, and the position (A) of the lower end 3 a of the heating device 3 is the origin. The horizontal axis indicates the temperature. In addition, B in a figure is a position of the front-end | tip part of the nozzle 10, and the distance from A is 185 mm, for example. C is the position of the upper end of the heating device 3, and the distance from A is, for example, 620 mm. D is the position of the fibrous filter 13, and the distance from A is 695 mm, for example. E is the position of the upper end of the reaction tube 2, and the distance from A is 1000 mm, for example. Referring to FIG. 14, it can be seen that a uniform temperature distribution of each set temperature (1300 ° C., 1400 ° C., 1500 ° C.) is obtained at least in a region where the distance from A is 150 mm to 450 mm. In particular, when the set temperature is 1400 ° C., the temperature distribution in the region is in the range of 1350 ° C. to 1450 ° C. Also, it can be seen that the tip of the nozzle 10 and the tip of the shroud 19 are in a region where a uniform temperature distribution of each set temperature is obtained. Therefore, the aluminum trichloride gas supplied from the nozzle 10 and the ammonia gas supplied from the gas line 4 have a uniform temperature distribution region in the reaction chamber 2a (for example, 1350 ° C. when the set temperature is 1400 ° C. In the region of 1450 ° C. or lower).
　なお、製造装置１Ｂを用いた窒化アルミニウム結晶粒子の製造方法は、前述した第１実施形態と同様である。したがって、本実施形態の製造装置１Ｂ及びこれを用いた窒化アルミニウム結晶粒子の製造方法は、第１実施形態と同様の作用効果を奏することができる。但し、本実施形態では、シュラウド１９に内管筒１９ｂが設けられており、内管筒１９ｂの先端部がノズル１０の先端部の位置付近まで延伸されている。これにより、ノズル１０から吹き出す三塩化アルミニウムガス、ノズル１０と内管筒１９ｂとの隙間から吹き出す窒素ガス、及び内管筒１９ｂと反応管２の内壁との隙間から吹き出すアンモニアガスが、層流の状態で反応室２ａの奥深く到達することができる。そして、この間、三塩化アルミニウムガスとアンモニアガスとが緩やかに反応する。 In addition, the manufacturing method of the aluminum nitride crystal particle using the manufacturing apparatus 1B is the same as that of 1st Embodiment mentioned above. Therefore, the manufacturing apparatus 1B of the present embodiment and the method of manufacturing aluminum nitride crystal particles using the same can achieve the same effects as those of the first embodiment. However, in the present embodiment, the inner tube 19 b is provided in the shroud 19, and the tip of the inner tube 19 b extends to the vicinity of the position of the tip of the nozzle 10. Thereby, the aluminum trichloride gas blown from the nozzle 10, the nitrogen gas blown from the gap between the nozzle 10 and the inner tube 19b, and the ammonia gas blown from the gap between the inner tube 19b and the inner wall of the reaction tube 2 are laminar. In this state, it can reach deep inside the reaction chamber 2a. During this time, the aluminum trichloride gas and the ammonia gas react slowly.
　ここで、反応室２ａにおける窒化アルミニウム結晶粒子の生成は、次のような過程を経て行われると考えられる。まず、アンモニアガスと三塩化アルミニウムガスとが反応することにより、窒化アルミニウム結晶粒子の形成の基となる微小な核が生成される。この核は、反応条件に応じて単結晶若しくは多結晶となるが、第１実施形態や本実施形態の反応条件下では殆どが単結晶となる。そして、更にアンモニアガス及び三塩化アルミニウムガスが供給されることによって、核の周囲に結晶が成長し、粒子が次第に大きくなる。このとき、核が単結晶であれば成長後の粒子も単結晶となり、核が多結晶であれば成長後の粒子も多結晶となる。 Here, it is considered that the generation of aluminum nitride crystal particles in the reaction chamber 2a is performed through the following process. First, by reacting ammonia gas with aluminum trichloride gas, minute nuclei that form the basis for forming aluminum nitride crystal particles are generated. Depending on the reaction conditions, these nuclei are single crystals or polycrystals, but most of them are single crystals under the reaction conditions of the first embodiment and this embodiment. Further, by supplying ammonia gas and aluminum trichloride gas, crystals grow around the nuclei, and the particles gradually increase. At this time, if the nucleus is a single crystal, the grown particle is also a single crystal, and if the nucleus is polycrystalline, the grown particle is also polycrystalline.
　上述したように、本実施形態では内管筒１９ｂの作用によって三塩化アルミニウムガスとアンモニアガスとが緩やかに反応する。そして、本発明者の知見によれば、三塩化アルミニウムガスとアンモニアガスとの反応が緩やかであるほど、反応室２ａ内に供給される三塩化アルミニウムガス及びアンモニアガスのうち核の生成に寄与する割合が抑えられ、粒子成長に寄与する割合が増加する。したがって、比較的大きな窒化アルミニウム結晶粒子をより好適に製造することができる。また、反応室２ａ内において核の生成が抑えられるような条件下では、核の多結晶化も抑制される。したがって、単結晶からなる窒化アルミニウム結晶粒子をより好適に製造することができる。 As described above, in the present embodiment, aluminum trichloride gas and ammonia gas react slowly by the action of the inner tube 19b. According to the knowledge of the present inventor, the milder the reaction between the aluminum trichloride gas and the ammonia gas, the more the aluminum trichloride gas and the ammonia gas supplied into the reaction chamber 2a contribute to the generation of nuclei. The ratio is suppressed, and the ratio contributing to particle growth increases. Therefore, relatively large aluminum nitride crystal particles can be more suitably produced. Further, under the condition that the generation of nuclei in the reaction chamber 2a is suppressed, the crystallization of the nuclei is also suppressed. Therefore, it is possible to more suitably manufacture aluminum nitride crystal particles made of a single crystal.
　（実施例７）
内管筒１９ｂの有無、反応室内の温度、および塩化水素ガスの流量が窒化アルミニウム結晶粒子の形成に与える影響を調べるために、次の実験を行った。まず、実施例１と同様の構成を備える製造装置１Ａと、第２実施形態に係る製造装置１Ｂとを準備した。なお、製造装置１Ｂの反応管２は、内径６０ｍｍ、高さ１０００ｍｍである高純度アルミナ製縦型反応管であり、加熱装置３としての電気管状炉の加熱部の長さは５００ｍｍであった。ノズル１０の外径は６ｍｍであり、内径は４ｍｍであった。内管筒１９ｂの外径は２５ｍｍであり、内径は２０ｍｍであった。 (Example 7)
In order to investigate the influence of the presence or absence of the inner tube 19b, the temperature in the reaction chamber, and the flow rate of hydrogen chloride gas on the formation of aluminum nitride crystal particles, the following experiment was performed. First, a manufacturing apparatus 1A having the same configuration as that of Example 1 and a manufacturing apparatus 1B according to the second embodiment were prepared. The reaction tube 2 of the production apparatus 1B was a high-purity alumina vertical reaction tube having an inner diameter of 60 mm and a height of 1000 mm, and the length of the heating portion of the electric tubular furnace as the heating device 3 was 500 mm. The outer diameter of the nozzle 10 was 6 mm, and the inner diameter was 4 mm. The outer diameter of the inner tube 19b was 25 mm, and the inner diameter was 20 mm.
　反応室７ａに金属アルミニウムを設置し、金属アルミニウムが約６００℃になるまで加熱した。その後、２０％窒素希釈の塩化水素ガスを１５ｓｃｃｍ、２０ｓｃｃｍ、２５ｓｃｃｍ及び５０ｓｃｃｍのうち何れかの流量（塩化水素ガスのみの流量に換算すると、それぞれ３ｓｃｃｍ、４ｓｃｃｍ、５ｓｃｃｍ及び１０ｓｃｃｍ）で反応室７ａに供給し、三塩化アルミニウムガスを生成させた。続いて、反応室２ａの温度を１３００℃、１３５０℃、１４００℃、１４５０℃、及び１５００℃の何れかに設定し、ガスライン４から供給されたアンモニアガスと三塩化アルミニウムガスとを反応させて、窒化アルミニウム結晶粒子を製造した。なお、ガスライン６から供給される窒素ガスの流量を５００ｓｃｃｍとし、ガスライン４からアンモニアガスと共に供給される窒素ガスの流量を、２０％窒素希釈の塩化水素ガスの流量と合わせて１５００ｓｃｃｍとなるように設定した。 Metal aluminum was installed in the reaction chamber 7a and heated until the metal aluminum reached about 600 ° C. Thereafter, hydrogen chloride gas diluted with 20% nitrogen is supplied to the reaction chamber 7a at a flow rate of 15 sccm, 20 sccm, 25 sccm, and 50 sccm (3 sccm, 4 sccm, 5 sccm, and 10 sccm, respectively, when converted to the flow rate of hydrogen chloride gas only). Then, aluminum trichloride gas was generated. Subsequently, the temperature of the reaction chamber 2a is set to any of 1300 ° C., 1350 ° C., 1400 ° C., 1450 ° C., and 1500 ° C., and the ammonia gas supplied from the gas line 4 is reacted with aluminum trichloride gas. Then, aluminum nitride crystal particles were produced. The flow rate of nitrogen gas supplied from the gas line 6 is set to 500 sccm, and the flow rate of nitrogen gas supplied from the gas line 4 together with the ammonia gas is set to 1500 sccm together with the flow rate of hydrogen chloride gas diluted with 20% nitrogen. Set to.
　図１５は、本実施例において製造された窒化アルミニウム結晶粒子の試料番号と、各試料番号における反応室内の設定温度、塩化水素ガス流量、内管筒１９ｂの有無、およびノズル１０の先端部の位置を基準とする内管筒１９ｂの先端部の位置（反応管２の端面２ｃ側を正とする）を示す図表である。なお、内管筒１９ｂが有る場合に、設定温度が１３００℃以上１４００℃以下の試料では、内管筒１９ｂの先端部の位置をノズル１０の先端部の位置に対して端面２ｂ側に設け、設定温度が１４５０℃以上１５００℃以下の試料では、内管筒１９ｂの先端部の位置をノズル１０の先端部の位置に対して端面２ｃ側に設けた。 FIG. 15 shows the sample numbers of the aluminum nitride crystal particles produced in this example, the set temperature in the reaction chamber, the hydrogen chloride gas flow rate, the presence or absence of the inner tube 19b, and the position of the tip of the nozzle 10 for each sample number. Is a chart showing the position of the tip of the inner tube cylinder 19b with reference to (the end surface 2c side of the reaction tube 2 is positive). In the case where there is the inner tube 19b, in a sample having a set temperature of 1300 ° C. or more and 1400 ° C. or less, the position of the tip of the inner tube 19b is provided on the end face 2b side with respect to the position of the tip of the nozzle 10, In a sample having a set temperature of 1450 ° C. or higher and 1500 ° C. or lower, the position of the tip of the inner tube 19b was provided on the end face 2c side with respect to the position of the tip of the nozzle 10.
　以下、図１５に示された各試料＃１０１～＃１１６に基づいて、内管筒１９ｂの有無、反応室内の温度、および塩化水素ガスの流量などが窒化アルミニウム結晶粒子の形成に与える影響について調べた結果を説明する。 Hereinafter, based on the samples # 101 to # 116 shown in FIG. 15, the influence of the presence / absence of the inner tube 19b, the temperature in the reaction chamber, the flow rate of hydrogen chloride gas, etc. on the formation of aluminum nitride crystal particles will be investigated. The results will be described.
　＜内管筒の有無が窒化アルミニウム結晶粒子の形成に与える影響について＞
図１６は、内管筒１９ｂの有無による窒化アルミニウム結晶粒子の結晶性への影響を示すグラフである。図１６において、横軸は塩化水素ガス流量（単位：ｓｃｃｍ）を示しており、縦軸はＸ線回折結果の半値全幅（ＦＷＨＭ、単位：度）を示している。図１６には、内管筒１９ｂが無い場合として試料＃１０９及び＃１１０が、内管筒１９ｂが有る場合として試料＃１０８及び＃１０４が、それぞれプロットされている。また、図１７は、内管筒１９ｂが無い場合（（ａ）試料＃１０９、（ｂ）試料＃１１０）における窒化アルミニウム結晶粒子のＳＥＭ写真であり、図１８は、内管筒１９ｂが有る場合（（ａ）試料＃１０８、（ｂ）試料＃１０４）における窒化アルミニウム結晶粒子のＳＥＭ写真である。 <Effect of presence or absence of inner tube on formation of aluminum nitride crystal particles>
FIG. 16 is a graph showing the influence on the crystallinity of the aluminum nitride crystal particles with and without the inner tube 19b. In FIG. 16, the horizontal axis represents the hydrogen chloride gas flow rate (unit: sccm), and the vertical axis represents the full width at half maximum (FWHM, unit: degree) of the X-ray diffraction result. In FIG. 16, samples # 109 and # 110 are plotted when there is no inner tube 19b, and samples # 108 and # 104 are plotted when there is an inner tube 19b. FIG. 17 is an SEM photograph of aluminum nitride crystal particles when there is no inner tube 19b ((a) sample # 109, (b) sample # 110), and FIG. 18 shows a case where there is an inner tube 19b. It is a SEM photograph of the aluminum nitride crystal grain in ((a) sample # 108, (b) sample # 104).
　図１６に示されるように、塩化水素ガスの流量に拘わらず、内管筒１９ｂが有る場合（＃１０８，＃１０４）には、内管筒１９ｂが無い場合（＃１０９，＃１１０）よりもＸ線回折結果のＦＷＨＭが小さくなった。このことは、シュラウドに内管筒が設けられることによって、窒化アルミニウム結晶粒子の結晶性が改善されることを表している。この事実は、図１７及び図１８に示されたＳＥＭ写真によって裏付けられる。したがって、第２実施形態のように、シュラウド１９は内管筒１９ｂを有することが好ましい。 As shown in FIG. 16, regardless of the flow rate of hydrogen chloride gas, when the inner tube 19b is present (# 108, # 104), compared to when there is no inner tube 19b (# 109, # 110). The FWHM of the X-ray diffraction result was reduced. This indicates that the crystallinity of the aluminum nitride crystal particles is improved by providing the inner tube on the shroud. This fact is supported by the SEM photographs shown in FIGS. Therefore, as in the second embodiment, the shroud 19 preferably has an inner tube 19b.
　＜反応室内の設定温度が窒化アルミニウム結晶粒子の形成に与える影響について＞
図１９は、反応室２ａ内の設定温度による窒化アルミニウム結晶粒子の結晶性への影響を示すグラフである。図１９において、横軸は反応室２ａ内の設定温度（単位：度）を示しており、縦軸はＸ線回折結果のＦＷＨＭ（単位：度）を示している。図１９には、ＨＣｌ流量が１０ｓｃｃｍである試料＃１０１、＃１０２、＃１０３及び＃１０４がプロットされており、また、ＨＣｌ流量が５ｓｃｃｍである試料＃１０８、＃１１１、＃１１２、＃１１４、＃１１５が、それぞれプロットされている。また、図２０（ａ）、図２０（ｂ）、図２１（ａ）、図２１（ｂ）、図２２（ａ）及び図２２（ｂ）それぞれは、試料＃１０１、＃１０２、＃１０３、＃１０４、＃１１１、＃１１２それぞれにおける窒化アルミニウム結晶粒子のＳＥＭ写真である。また、図２３（ａ）は、試料＃１１５における窒化アルミニウム結晶粒子のＳＥＭ写真であり、図２３（ｂ）は図２３（ａ）を拡大したＳＥＭ写真であり、図２３（ｃ）は図２３（ｂ）を更に拡大したＳＥＭ写真である。 <Effect of set temperature in reaction chamber on formation of aluminum nitride crystal particles>
FIG. 19 is a graph showing the influence of the set temperature in the reaction chamber 2a on the crystallinity of the aluminum nitride crystal particles. In FIG. 19, the horizontal axis indicates the set temperature (unit: degree) in the reaction chamber 2a, and the vertical axis indicates the FWHM (unit: degree) of the X-ray diffraction result. In FIG. 19, samples # 101, # 102, # 103, and # 104 with an HCl flow rate of 10 sccm are plotted, and samples # 108, # 111, # 112, # 114, with an HCl flow rate of 5 sccm, are plotted. Each of # 115 is plotted. 20 (a), 20 (b), 21 (a), 21 (b), 22 (a), and 22 (b) respectively show samples # 101, # 102, # 103, It is a SEM photograph of aluminum nitride crystal grains in each of # 104, # 111, and # 112. FIG. 23A is an SEM photograph of aluminum nitride crystal particles in Sample # 115, FIG. 23B is an enlarged SEM photograph of FIG. 23A, and FIG. It is the SEM photograph which expanded (b) further.
　図１９に示されるように、反応室２ａの設定温度が１４５０℃以下である場合に、Ｘ線回折結果のＦＷＨＭが０．３よりも小さくなり、十分な窒化アルミニウム結晶粒子の結晶性が得られた。また、反応室２ａの設定温度が１４００℃である場合にＸ線回折結果のＦＷＨＭが最も小さくなった。この結果から、反応室２ａの設定温度は１４５０℃以下であることが好ましく、１４００℃である（すなわち、温度分布が１３５０℃以上１４５０℃以下の範囲内に含まれる）ことが更に好ましい。 As shown in FIG. 19, when the set temperature of the reaction chamber 2a is 1450 ° C. or lower, the FWHM of the X-ray diffraction result becomes smaller than 0.3, and sufficient crystallinity of the aluminum nitride crystal particles can be obtained. It was. Further, when the set temperature of the reaction chamber 2a was 1400 ° C., the FWHM of the X-ray diffraction result was the smallest. From this result, the set temperature of the reaction chamber 2a is preferably 1450 ° C. or less, more preferably 1400 ° C. (that is, the temperature distribution is included in the range of 1350 ° C. to 1450 ° C.).
　＜塩化水素ガス流量が窒化アルミニウム結晶粒子の形成に与える影響について＞
図２４は、塩化水素ガス流量による窒化アルミニウム結晶粒子の結晶性への影響を示すグラフである。図２４において、横軸は塩化水素ガス流量（単位：ｓｃｃｍ）を示しており、縦軸はＸ線回折結果のＦＷＨＭ（単位：度）を示している。図２４には、反応室内の設定温度が１４００℃である試料＃１０４、＃１０８、＃１１３及び＃１１６がプロットされている。また、図２５は試料＃１１３における窒化アルミニウム結晶粒子のＳＥＭ写真である。また、図２６（ａ）は、試料＃１１６における窒化アルミニウム結晶粒子のＳＥＭ写真であり、図２６（ｂ）は図２６（ａ）を拡大したＳＥＭ写真であり、図２６（ｃ）は図２６（ｂ）を更に拡大したＳＥＭ写真である。なお、試料＃１０４及び＃１０８のＳＥＭ写真については、図１８に示されている。 <Effect of hydrogen chloride gas flow rate on formation of aluminum nitride crystal particles>
FIG. 24 is a graph showing the influence of the flow rate of hydrogen chloride gas on the crystallinity of aluminum nitride crystal particles. In FIG. 24, the horizontal axis indicates the hydrogen chloride gas flow rate (unit: sccm), and the vertical axis indicates the FWHM (unit: degree) of the X-ray diffraction result. In FIG. 24, samples # 104, # 108, # 113 and # 116 in which the set temperature in the reaction chamber is 1400 ° C. are plotted. FIG. 25 is an SEM photograph of aluminum nitride crystal particles in Sample # 113. FIG. 26 (a) is an SEM photograph of aluminum nitride crystal particles in sample # 116, FIG. 26 (b) is an enlarged SEM photograph of FIG. 26 (a), and FIG. 26 (c) is FIG. It is the SEM photograph which expanded (b) further. Note that SEM photographs of samples # 104 and # 108 are shown in FIG.
　図２４に示されるように、塩化水素ガス流量が４ｓｃｃｍ以上である場合に、Ｘ線回折結果のＦＷＨＭが０．２３よりも小さくなり、十分な窒化アルミニウム結晶粒子の結晶性が得られた。特に、塩化水素ガス流量が４ｓｃｃｍ以上５ｓｃｃｍ以下である場合には、ＦＷＨＭが０．２２よりも小さくなり、極めて結晶性の良好な窒化アルミニウム結晶粒子を得るに至った。 As shown in FIG. 24, when the hydrogen chloride gas flow rate was 4 sccm or more, the FWHM of the X-ray diffraction result was smaller than 0.23, and sufficient crystallinity of the aluminum nitride crystal particles was obtained. In particular, when the hydrogen chloride gas flow rate is 4 sccm or more and 5 sccm or less, the FWHM is smaller than 0.22, and aluminum nitride crystal particles having extremely good crystallinity are obtained.
　＜窒化アルミニウム結晶粒子の大きさについて＞
続いて、図１５に示された各試料のうち、試料＃１０８、＃１１２及び＃１１３に基づいて、窒化アルミニウム結晶粒子の大きさを測定した結果について説明する。図２７は、試料＃１０８（設定温度１４００℃、ＨＣｌ流量５ｓｃｃｍ）のＳＥＭ写真であり、図２８は、この写真に含まれる個々の窒化アルミニウム結晶粒子を測定することにより求められた試料＃１０８の（ａ）粒径分布及び（ｂ）厚さ分布を示すヒストグラムである。同様に、図２９は、試料＃１１２（設定温度１３５０℃、ＨＣｌ流量５ｓｃｃｍ）のＳＥＭ写真であり、図３０は、この写真から求められた試料＃１１２の（ａ）粒径分布及び（ｂ）厚さ分布を示すヒストグラムである。また、図３１は、試料＃１１３（設定温度１４００℃、ＨＣｌ流量４ｓｃｃｍ）のＳＥＭ写真であり、図３２は、この写真から求められた試料＃１１３の（ａ）粒径分布及び（ｂ）厚さ分布を示すヒストグラムである。なお、図２８（ａ）、図３０（ａ）及び図３２（ａ）において、粒径とは、窒化アルミニウム結晶粒子の平面形状（六角形）において対向する辺の間隔を表し、厚さとは、窒化アルミニウム結晶粒子の上記平面形状に垂直な方向における一対の端面間の距離を表している。 <About the size of aluminum nitride crystal grains>
Next, the results of measuring the size of the aluminum nitride crystal particles based on the samples # 108, # 112, and # 113 among the samples shown in FIG. 15 will be described. FIG. 27 is an SEM photograph of sample # 108 (setting temperature 1400 ° C., HCl flow rate 5 sccm), and FIG. 28 is a view of sample # 108 obtained by measuring individual aluminum nitride crystal particles included in this photograph. It is a histogram which shows (a) particle size distribution and (b) thickness distribution. Similarly, FIG. 29 is an SEM photograph of sample # 112 (set temperature 1350 ° C., HCl flow rate 5 sccm), and FIG. 30 shows (a) particle size distribution and (b) of sample # 112 obtained from this photograph. It is a histogram which shows thickness distribution. FIG. 31 is a SEM photograph of sample # 113 (set temperature 1400 ° C., HCl flow rate 4 sccm), and FIG. 32 shows (a) particle size distribution and (b) thickness of sample # 113 obtained from this photograph. It is a histogram which shows thickness distribution. In FIG. 28A, FIG. 30A and FIG. 32A, the particle size represents the interval between opposing sides in the planar shape (hexagon) of the aluminum nitride crystal particles, and the thickness is It represents the distance between a pair of end faces in a direction perpendicular to the planar shape of the aluminum nitride crystal particles.
　図２８（ａ）、図３０（ａ）及び図３２（ａ）に示されるように、試料＃１０８、＃１１２及び＃１１３のいずれにおいても、窒化アルミニウム結晶粒子の粒径は０．１μｍ以上１．０μｍ以下の範囲内に収まっていることがわかる。また、図２８（ｂ）、図３０（ｂ）及び図３２（ｂ）に示されるように、窒化アルミニウム結晶粒子の厚さは、試料＃１０８では０．１μｍ以上０．４μｍ以下の範囲内に収まっており、試料＃１１２では０．１μｍ以上０．５μｍ以下の範囲内に収まっており、試料＃１１３では０．１μｍ以上０．６μｍ以下の範囲内に収まっていることがわかる。 As shown in FIGS. 28 (a), 30 (a), and 32 (a), in any of samples # 108, # 112, and # 113, the particle size of the aluminum nitride crystal particles is 0.1 μm or more and 1 It can be seen that it is within the range of 0.0 μm or less. Further, as shown in FIGS. 28B, 30B, and 32B, the thickness of the aluminum nitride crystal particles is within the range of 0.1 μm or more and 0.4 μm or less in the sample # 108. It can be seen that the sample # 112 falls within the range of 0.1 μm to 0.5 μm, and the sample # 113 falls within the range of 0.1 μm to 0.6 μm.
　＜窒化アルミニウム結晶粒子の形状について＞
図２７、図２９及び図３１に示された試料＃１０８、＃１１２及び＃１１３のＳＥＭ写真を参照すると、本実施例により製造された窒化アルミニウム結晶粒子の中には、六角錐台（すなわち、六角柱の側面が底面及び上面に対して傾斜している形状）といった外形を有するものが多数確認された。また、これらのＳＥＭ写真を参照すると、六角柱状（典型的には、厚さが粒径よりも小さいもの）といった外形を有するものも多数確認された。また、これらのＳＥＭ写真を参照すると、六角柱状であるが厚さが粒径よりも極めて小さく、六角板状といった外形を有するものも確認された。 <About the shape of aluminum nitride crystal particles>
Referring to SEM photographs of Samples # 108, # 112, and # 113 shown in FIGS. 27, 29, and 31, some of the aluminum nitride crystal particles produced according to this example include a hexagonal frustum (that is, A number of hexagonal pillars having an outer shape such that the side surface of the hexagonal column is inclined with respect to the bottom surface and the top surface were confirmed. Further, referring to these SEM photographs, a large number of hexagonal columnar shapes (typically those having a thickness smaller than the particle size) were confirmed. Further, referring to these SEM photographs, it was confirmed that the film had a hexagonal column shape, but the thickness was extremely smaller than the particle diameter, and had an outer shape such as a hexagonal plate shape.
　また、図３３（ａ）及び図３３（ｂ）は、図３１に示された試料＃１１３のＳＥＭ写真のそれぞれ一部を拡大した写真である。これらの写真に示されるように、本実施例により製造された窒化アルミニウム結晶粒子の中には、２つの六角錐台の底面同士が結合された形状が多数確認された。このような形状を言い換えると、窒化アルミニウム結晶粒子は、厚さ方向と交差する平面に沿った正六角形状の一対の端面を有しており、厚さ方向に垂直な断面が正六角形であり、且つ、厚さ方向の中央部分における六角形断面の径が、一対の六角形端面の径よりも大きい。 33 (a) and 33 (b) are photographs in which a part of each SEM photograph of sample # 113 shown in FIG. 31 is enlarged. As shown in these photographs, a number of shapes in which the bottom surfaces of two hexagonal frustums were combined were confirmed in the aluminum nitride crystal particles produced according to this example. In other words, the aluminum nitride crystal particles have a pair of regular hexagonal end faces along a plane intersecting the thickness direction, and the cross section perpendicular to the thickness direction is a regular hexagon. And the diameter of the hexagonal cross section in the center part of thickness direction is larger than the diameter of a pair of hexagonal end surface.
　＜窒化アルミニウム結晶粒子のＣＬ強度について＞
図３４は、本実施例に係る試料＃１０４、＃１０８、＃１０９、＃１１０、＃１１１、＃１１２及び＃１１３のそれぞれにおける窒化アルミニウム結晶粒子の電子線励起発光（ＣＬ）の強度とその光の波長との関係を測定した結果である。図３４（ａ）には試料＃１０４、＃１０８、＃１０９及び＃１１０に関するグラフが示されており、図３４（ｂ）には試料＃１０８、＃１１１、＃１１２及び＃１１３に関するグラフが示されている。なお、これらのＣＬ強度は室温環境にて測定され、電子ビーム加速電圧は１０ｋＶ、電流密度は６０μＡ／ｃｍ２、測定時間は１００ｍｓであった。 <CL strength of aluminum nitride crystal particles>
FIG. 34 shows the intensity and light of electron beam excitation luminescence (CL) of aluminum nitride crystal particles in each of samples # 104, # 108, # 109, # 110, # 111, # 112, and # 113 according to this example. It is the result of having measured the relationship with the wavelength. FIG. 34A shows graphs related to samples # 104, # 108, # 109, and # 110, and FIG. 34B shows graphs related to samples # 108, # 111, # 112, and # 113. Has been. These CL intensities were measured in a room temperature environment, the electron beam acceleration voltage was 10 kV, the current density was 60 μA / cm 2 , and the measurement time was 100 ms.
　図３４に示されるように、測定に使用された試料のうち、試料＃１１３（設定温度１４００℃、ＨＣｌ流量４ｓｃｃｍ）におけるＣＬ強度が最も高く、次いで、試料＃１１２（設定温度１３５０℃、ＨＣｌ流量５ｓｃｃｍ）におけるＣＬ強度が高く、試料＃１０８（設定温度１４００℃、ＨＣｌ流量５ｓｃｃｍ）におけるＣＬ強度がそれらに次いで高い結果となった。この結果から、反応室２ａの設定温度が１４００℃である（すなわち温度分布が１３５０℃以上１４５０℃以下の範囲内に含まれる）場合に、窒化アルミニウム結晶粒子の結晶性が極めて良好となることがわかる。 As shown in FIG. 34, among the samples used for the measurement, CL intensity was highest in sample # 113 (set temperature 1400 ° C., HCl flow rate 4 sccm), and then sample # 112 (set temperature 1350 ° C., HCl flow rate) The CL intensity at 5 sccm) was high, and the CL intensity at sample # 108 (setting temperature 1400 ° C., HCl flow rate 5 sccm) was the second highest. From this result, when the set temperature of the reaction chamber 2a is 1400 ° C. (that is, the temperature distribution is included in the range of 1350 ° C. or more and 1450 ° C. or less), the crystallinity of the aluminum nitride crystal particles becomes extremely good. Recognize.
　本発明による窒化アルミニウム結晶粒子の製造方法、及び該方法により製造された窒化アルミニウム結晶粒子は、上記した実施形態及び実施例に限られるものではなく、他に様々な変形が可能である。 The method for producing aluminum nitride crystal particles according to the present invention and the aluminum nitride crystal particles produced by the method are not limited to the above-described embodiments and examples, and various other modifications are possible.
　本発明は、単結晶の窒化アルミニウム結晶粒子を効率よく製造することができる窒化アルミニウム結晶粒子の製造装置および該製造装置を用いた窒化アルミニウム結晶粒子の製造方法、並びにそのような製造装置を用いた製造方法により製造される窒化アルミニウム結晶粒子として利用可能である。 The present invention uses an apparatus for producing aluminum nitride crystal particles capable of efficiently producing single-crystal aluminum nitride crystal particles, a method for producing aluminum nitride crystal particles using the production apparatus, and such a production apparatus. It can be used as aluminum nitride crystal particles produced by the production method.
　１Ａ，１Ｂ…製造装置、２ａ…第２の反応室、４～６…ガスライン、７ａ…第１の反応室、８…原料、９，１９…シュラウド、１２…排気管、１３…繊維性フィルタ。 DESCRIPTION OF SYMBOLS 1A, 1B ... Manufacturing apparatus, 2a ... 2nd reaction chamber, 4-6 ... Gas line, 7a ... 1st reaction chamber, 8 ... Raw material, 9,19 ... Shroud, 12 ... Exhaust pipe, 13 ... Fiber filter .

Claims (9)

  1. 　粒子の形状が各々独立した六角柱、六角鼓形、六角錐台、及び、２つの六角錐台の底面同士が結合された形状のうち何れかであり、粒径が０．０５μｍ以上１μｍ以下である、窒化アルミニウム結晶粒子。 The particle shape is any of hexagonal prism, hexagonal drum shape, hexagonal frustum, and two hexagonal frustum shapes that are joined to each other, and the particle size is 0.05 μm or more and 1 μm or less. Some aluminum nitride crystal particles.
  2. 　塩化水素ガスと、融点以下の温度に加熱されたアルミニウムとを反応させて、塩化アルミニウムガスを発生させる第１の反応室と、
    　アンモニアガスと前記塩化アルミニウムガスとを反応させて、窒化アルミニウム結晶粒子を成長させる第２の反応室と、
    　前記第１の反応室及び前記第２の反応室を加熱する加熱装置と、
    　前記アンモニアガスと前記塩化アルミニウムガスとを前記第２の反応室まで隔離するシュラウドと
    を備えている、窒化アルミニウム結晶粒子の製造装置。     A first reaction chamber in which hydrogen chloride gas and aluminum heated to a temperature below the melting point are reacted to generate aluminum chloride gas;
    A second reaction chamber in which ammonia gas and the aluminum chloride gas are reacted to grow aluminum nitride crystal particles;
    A heating device for heating the first reaction chamber and the second reaction chamber;
    An apparatus for producing aluminum nitride crystal particles, comprising: a shroud that isolates the ammonia gas and the aluminum chloride gas to the second reaction chamber.
  3. 　前記窒化アルミニウム結晶粒子は、排気管に設置された繊維性フィルタにより捕集される、請求項２記載の窒化アルミニウム結晶粒子の製造装置。 The apparatus for producing aluminum nitride crystal particles according to claim 2, wherein the aluminum nitride crystal particles are collected by a fibrous filter installed in an exhaust pipe.
  4. 　前記第２の反応室の温度は、１３５０℃以上１４５０℃以下の範囲内である、請求項２又は３記載の窒化アルミニウム結晶粒子の製造装置。 The apparatus for producing aluminum nitride crystal particles according to claim 2 or 3, wherein the temperature of the second reaction chamber is in the range of 1350 ° C or higher and 1450 ° C or lower.
  5. 　シュラウドによりアンモニアガスから隔離された第１の反応室に設置されたアルミニウムを該アルミニウムの融点以下の温度に加熱し、前記アルミニウムと前記第１の反応室へ供給された塩化水素ガスとを反応させて、前記第１の反応室で塩化アルミニウムガスを発生させ、前記塩化アルミニウムガスとアンモニアガスとを第２の反応室で反応させて、前記第２の反応室で窒化アルミニウム結晶粒子を成長させる、窒化アルミニウム結晶粒子の製造方法。 The aluminum installed in the first reaction chamber isolated from the ammonia gas by the shroud is heated to a temperature not higher than the melting point of the aluminum to react the aluminum and hydrogen chloride gas supplied to the first reaction chamber. Generating aluminum chloride gas in the first reaction chamber, causing the aluminum chloride gas and ammonia gas to react in the second reaction chamber, and growing aluminum nitride crystal particles in the second reaction chamber; A method for producing aluminum nitride crystal particles.
  6. 　前記窒化アルミニウム結晶粒子は、排気管に設置された繊維性フィルタにより捕集される、請求項５記載の窒化アルミニウム結晶粒子の製造方法。 The method for producing aluminum nitride crystal particles according to claim 5, wherein the aluminum nitride crystal particles are collected by a fibrous filter installed in an exhaust pipe.
  7. 　前記第２の反応室の温度は、１３５０℃以上１４５０℃以下の範囲内である、請求項５又は６記載の窒化アルミニウム結晶粒子の製造方法。 The method for producing aluminum nitride crystal particles according to claim 5 or 6, wherein the temperature of the second reaction chamber is in the range of 1350 ° C to 1450 ° C.
  8. 　シュラウドによりアンモニアガスから隔離された第１の反応室に設置されたアルミニウムを該アルミニウムの融点以下の温度に加熱し、前記アルミニウムと前記第１の反応室へ供給された塩素原子とを含むガスと反応させて、前記第１の反応室で塩化アルミニウムガスを発生させ、前記塩化アルミニウムガスとアンモニアガスとを第２の反応室で反応させて、前記第２の反応室で窒化アルミニウム結晶粒子を成長させることにより製造された、窒化アルミニウム結晶粒子。 Heating the aluminum installed in the first reaction chamber isolated from the ammonia gas by the shroud to a temperature below the melting point of the aluminum, and containing the aluminum and a chlorine atom supplied to the first reaction chamber; Reaction is performed to generate aluminum chloride gas in the first reaction chamber, and the aluminum chloride gas and ammonia gas are reacted in the second reaction chamber to grow aluminum nitride crystal particles in the second reaction chamber. Aluminum nitride crystal particles produced by causing
  9. 　前記窒化アルミニウム結晶粒子の形状は、各々独立した六角柱、六角鼓形、六角錐台、及び、２つの六角錐台の底面同士が結合された形状のうち何れかであって、
    　前記窒化アルミニウム結晶粒子の粒径は、０．０５μｍ以上１μｍ以下である、請求項８記載の窒化アルミニウム結晶粒子。     The shape of the aluminum nitride crystal particles is any of a hexagonal column, a hexagonal drum, a hexagonal frustum, and a shape in which the bottom surfaces of two hexagonal frustums are joined to each other,
    The aluminum nitride crystal particles according to claim 8, wherein the aluminum nitride crystal particles have a particle size of 0.05 μm or more and 1 μm or less.
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