JP2008115068A - Process for producing aluminum nitride containing material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a process for producing an aluminum nitride containing material at a low manufacturing cost. <P>SOLUTION: The process for producing the aluminum nitride containing material includes a first heat treatment step where a catalyst element having a smaller free energy of formation of nitride than that of aluminum is positioned in molten aluminum heated in a nitrogen atmosphere to cause nitridation using the catalyst element as a catalyst and form a material containing aluminum nitride. The catalyst element is at least one selected from a group consisting of boron, calcium, silicon, iron, molybdenum, chromium, vanadium, magnesium, manganese, indium, gallium, tantalum, hafnium and thorium. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing an aluminum nitride-containing material, and particularly relates to a method for producing a massive aluminum nitride-containing material or powdered aluminum nitride.

  Aluminum nitride is a material having excellent properties such as high thermal conductivity, low thermal expansion coefficient, and chemical stability. For this reason, in recent years, it is expected to be applied to various fields such as semiconductor devices and engine members.

Conventionally, as a method for producing aluminum nitride, there is a method in which aluminum is heated to a high temperature (for example, 1600 °) in a nitrogen atmosphere at a very high pressure (for example, 100 atm). According to this method, an aluminum nitride powder can be obtained. Non-Patent Document 1 discloses a study on the production of aluminum nitride.
Akira Kobashi, Kenzo Saiki et al., The 104th Annual Meeting of the Japan Institute of Light Metals (2003) 2.

  In the above-described method, in order to obtain aluminum nitride, it is necessary to set a very high pressure and high temperature. Therefore, the manufacturing cost of aluminum nitride has been high.

  Only aluminum nitride powder can be obtained. For this reason, in order to obtain an aluminum nitride-containing material having a desired shape, it has been necessary to add a binder to the aluminum nitride powder to obtain a desired shape and then to fire. For this reason, the manufacturing cost of the massive aluminum nitride-containing material has been further increased.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a method for producing an aluminum nitride-containing material at a low production cost.

In the method for producing an aluminum nitride-containing material according to the present invention, the catalyst element, which is an element whose free energy of formation of nitride is smaller than that of aluminum, is positioned in molten aluminum heated in a nitrogen atmosphere. There is provided a first heat treatment step for generating a nitriding reaction of aluminum as a catalyst to produce an aluminum nitride-containing material containing aluminum nitride.
The catalytic element is at least one selected from the group consisting of boron, calcium, silicon, iron, molybdenum, chromium, vanadium, magnesium, manganese, indium, gallium, tantalum, hafnium, and thorium.

  Catalyst element solid solution aluminum which is aluminum in which the catalyst element is solid solution, Catalyst element compound aluminum which is aluminum which forms a compound with the catalyst element, Mixture of catalyst element solid solution aluminum and catalyst element compound aluminum Alternatively, the catalytic element may be positioned in the molten aluminum under a nitrogen atmosphere by melting a mixture of aluminum and at least one of the catalytic element solid solution aluminum and the catalytic element compound aluminum under a nitrogen atmosphere.

  The catalyst element may be located in the molten aluminum by heating the substance containing the catalyst element and the aluminum in the same container to melt the aluminum. In this case, it is preferable to arrange the aluminum on the substance containing the catalytic element in the container and then melt the aluminum. Further, in this case, the aluminum is plate-like or lump-like, the substance containing the catalytic element is in the form of powder or particles, and after the powder or particles of the substance containing the catalytic element are attached to one surface of the aluminum The aluminum is preferably disposed on the material containing the catalytic element with the one surface facing downward. In addition, the aluminum is plate-like or massive, the substance containing the catalytic element is powder or particles, and the powder or particles of the substance containing the catalytic element are pressed on one surface of each of the plurality of aluminum. By adhering the powder or particles of the substance containing the catalytic element to one surface of each of the plurality of aluminum, the plurality of aluminum are placed with the catalytic element interposed between the surfaces with the one surface facing downward. The aluminum contained in the container may be stacked while sandwiching the powder or particles of the contained substance, and the lowermost aluminum may be disposed on the powder or particles of the substance containing the catalytic element.

  In the first heat treatment step, the arrangement density of the powder or particles of the substance containing the catalytic element in the peripheral part of the container is more than the arrangement density of the powder or particles of the substance containing the catalytic element in the central part of the container. May be higher.

  The heat treatment temperature in the first heat treatment step is preferably 700 ° C. or higher and 1400 ° C. or lower. In the first heat treatment step, the nitrogen gas atmosphere may be a pressurized atmosphere or a normal pressure. When pressurizing, the nitrogen gas atmosphere is preferably 50 atm or less.

  After the first heat treatment step, a second heat treatment step of cooling the aluminum nitride-containing material again and then heat-treating the aluminum nitride-containing material again in a nitrogen atmosphere may be provided. In this case, a step of processing the shape of the aluminum nitride-containing material may be provided between the first heat treatment step and the second heat treatment step. In the second heat treatment step, the nitrogen gas atmosphere may be a pressurized atmosphere or a normal pressure. When pressurizing, the nitrogen gas atmosphere is preferably 50 atm or less. The second heat treatment step may be repeated a plurality of times.

In the first heat treatment step, the temperature of the peripheral portion of the molten aluminum may be higher by 50 ° C. or more and 300 ° C. or less than the temperature of the central portion of the molten aluminum.
In the first heat treatment step, the relative position of the heating means for heating the molten aluminum with respect to the molten aluminum may be reciprocated up and down around the molten aluminum.

  In the aluminum nitride-containing material according to the present invention, the aluminum is dispersed in the form of islands in the bulk aluminum nitride, and the silicon is present in a state where silicon is dispersed in at least part of the grain boundaries of the aluminum and aluminum nitride. . The dispersion density of the aluminum may be inclined.

  According to the method for producing an aluminum nitride-containing composition of the present invention, an aluminum nitride-containing material can be produced without increasing the pressure to a very high level and without increasing the temperature as high as 1600 ° C. In particular, by adjusting the production conditions, a massive aluminum nitride-containing material can be produced directly. For this reason, a manufacturing cost becomes remarkably low.

  Below, the manufacturing method of the aluminum nitride containing composition which concerns on embodiment of this invention is demonstrated with reference to drawings.

  FIG. 1 is a configuration diagram of a carbon resistance furnace used in the method for producing an aluminum nitride-containing material according to the first embodiment. This carbon resistance furnace has a reaction chamber 10. The reaction chamber 10 is provided with an exhaust port (not shown) and a gas introduction port 11. A graphite heater 13 for heating the crucible 12 is provided in the reaction chamber 10. Since the crucible 12 is provided with a thermocouple, the temperature of the crucible 12 can be monitored outside the reaction chamber 10 through the monitor wire 14. The graphite heater 13 is controlled by a control unit (not shown). This control unit controls the output to the graphite heater 13 based on the temperature of the crucible 12, for example.

Next, the manufacturing method of the aluminum nitride containing material using said carbon resistance furnace is demonstrated.
First, by dissolving the catalytic element and aluminum, the catalytic element solid aluminum which is the aluminum in which the catalytic element is dissolved, the catalytic element compound aluminum which is the aluminum forming the compound with the catalytic element, the catalytic element solid solution A mixture of aluminum and the catalytic element compound aluminum, or a mixture of at least one of catalytic element solid solution aluminum and catalytic element compound aluminum and aluminum (hereinafter referred to as catalytic element-containing aluminum 20) is produced. The apparatus used in this step is, for example, an arc melting furnace, but may be a normal melting furnace. The catalytic element is an element whose free energy of formation of nitride is smaller than that of aluminum, for example, a group consisting of boron, calcium, silicon, iron, molybdenum, chromium, vanadium, magnesium, manganese, indium, gallium, tantalum, hafnium, and thorium. It is at least one kind selected from. When the catalytic element is boron, the catalytic element-containing aluminum 20 contains, for example, a compound of boron and aluminum (AlB _x ).

  Next, the catalyst element-containing aluminum 20 is disposed inside the crucible 12. Next, the inside of the reaction chamber 10 is exhausted from the exhaust port described above, and then nitrogen gas is introduced from the gas inlet 11. Thereby, the inside of the reaction chamber 10 becomes a nitrogen atmosphere. The pressure of the nitrogen gas inside the reaction chamber 10 may be a normal pressure, a pressurized atmosphere of 50 atm or less, and a reduced pressure atmosphere. In the case of a normal pressure or reduced pressure atmosphere, it is preferable to always supply nitrogen gas into the reaction chamber 10. For example, in the case of normal pressure, nitrogen gas overflows from the reaction chamber 10.

  Next, the crucible 12 is heated to, for example, 700 ° C. or higher and 1400 ° C. or lower with the graphite heater 13. Thereby, the catalytic element-containing aluminum 20 is melted in the crucible 12. In this state, the catalyst element reacts with nitrogen in the atmosphere and is nitrided. As described above, the catalytic element has a smaller free energy of formation of nitride than aluminum. For this reason, the nitrogen combined with the catalytic element is transferred to the aluminum, and the aluminum is nitrided. In this way, the nitriding reaction of aluminum using the catalyst element as a catalyst proceeds, and an aluminum nitride-containing material is formed (hereinafter referred to as first heat treatment). In the initial stage of the first heat treatment, the specific gravity of aluminum nitride is larger than that of aluminum, so that the generated aluminum nitride particles precipitate, and the nitriding reaction of aluminum proceeds above the aluminum nitride particles. As the generation of aluminum nitride proceeds, the aluminum nitride particles are combined to form a network, and the nitriding reaction of aluminum proceeds on the surface of the network-like aluminum nitride. The lower the pressure in the reaction chamber 10, the slower the rate of temperature rise in the temperature range above the melting point of the catalytic element-containing aluminum 20. For example, when the pressure in the reaction chamber 10 is a normal pressure, the rate of temperature increase in the temperature range above the melting point of the catalytic element-containing aluminum 20 is preferably 5 ° C./min or less.

  In the nitriding reaction of aluminum in the first heat treatment, the speed at which the nitriding reaction proceeds can be controlled by the processing temperature and the pressure of atmospheric nitrogen. Further, the state of the aluminum nitride-containing material can be made different depending on the processing conditions of the first heat treatment, such as the processing temperature, the pressure of atmospheric nitrogen, the reaction time, the ratio of boron nitride to aluminum, and the like.

(There was an expression that the porosity is 1% or less, but that part was deleted)
For example, under predetermined processing conditions, an aluminum nitride-containing material in which a plurality of aluminum nitride particles are bonded together by aluminum is obtained in the form of an aggregate (bulk), that is, a lump. In the obtained aluminum nitride-containing material, aluminum is located between a plurality of aluminum nitride particles, or aluminum is located between aluminum nitrides grown in a network shape, that is, a network. Thus, the void volume ratio is significantly reduced as compared with the aluminum nitride-containing material obtained by the sintering method, and a bulk aluminum nitride-containing material can be obtained. Note that the aluminum located between the aluminum nitrides grown in a network shape, that is, in a network shape, may contain aluminum nitride particles that do not form a network. Further, in the massive aluminum nitride-containing material, at least a part of the catalyst element is taken into the aluminum nitride and aluminum grain boundary in a state combined with aluminum.

  Under the conditions that promote the formation reaction of aluminum nitride (for example, 40 atm at 1300 ° C.), the proportion of aluminum nitride contained in the product, aluminum nitride-containing material, may be increased and the proportion of aluminum may be decreased. it can.

  When the aluminum content is 40% or more and 70 or less, the workability of the obtained aluminum nitride-containing material is improved. Further, when the aluminum content is 20% or less, the mechanical properties (hardness and the like) of aluminum nitride are high. When the aluminum content is 5% or less, the characteristics (including thermal conductivity and resistance) of the obtained aluminum nitride-containing material are close to those of pure AlN.

  When aluminum nitridation exceeds a certain level (for example, the aluminum nitride content is 99% or more), the aluminum nitride-containing material becomes a mixture of agglomerated coal (bulk) and powder, and further aluminum nitridation proceeds. The product becomes powdery. The powdered product is high purity aluminum nitride.

  Further, the higher the pressure of the nitrogen gas inside the reaction chamber 10, the higher the void volume ratio of the aluminum nitride-containing material, and the lower the thermal conductivity as the void volume ratio increases. For this reason, when it is desired to increase the void volume ratio, it is better to increase the pressure of the nitrogen gas inside the reaction chamber 10, and conversely, when it is desired to increase the thermal conductivity by decreasing the void volume ratio, It is preferable that the pressure of the nitrogen gas in is not more than normal pressure.

  As described above, according to the method for producing an aluminum nitride-containing material according to the present invention, a massive aluminum nitride-containing material can be easily obtained. The characteristics of the obtained aluminum nitride-containing material vary depending on the proportion of aluminum. For example, when the proportion of aluminum is high, the workability of the aluminum nitride-containing material is improved, and when the proportion of aluminum is low, the characteristics of the aluminum nitride-containing material are close to those of AlN. Moreover, since the surfaces of the aluminum nitride particles are covered with aluminum, good moisture resistance can be obtained.

  In addition, the manufacturing conditions are low temperature and low pressure as compared with the conventional method. Therefore, the manufacturing cost is significantly reduced as compared with the prior art. In addition, by adjusting the manufacturing conditions, powdered aluminum nitride can be manufactured. However, in this case as well, the manufacturing conditions are lower temperature and lower pressure than in the conventional case, so the manufacturing cost is lower than in the conventional case. Greatly reduced.

  A cooling mechanism for cooling the crucible 12 may be provided. For example, the above-described control unit controls the cooling mechanism based on the temperature of the crucible 12. For example, when the temperature of the crucible 12 starts to rise rapidly due to the nitridation reaction (exothermic reaction) of Al in the crucible 12, the control unit operates the cooling mechanism. Moreover, the above-mentioned control part can make the temperature profile of the crucible 12 into arbitrary profiles by controlling the graphite heater 13 and a cooling mechanism appropriately. For example, the control unit may maintain the crucible 12 at a constant temperature, or may periodically raise and lower the crucible 12 within a predetermined temperature.

  Next, the manufacturing method of the aluminum nitride containing material which concerns on 2nd Embodiment is demonstrated. In the present embodiment, a block-shaped aluminum nitride-containing material is manufactured by the first heat treatment shown in the first embodiment, and the obtained aluminum nitride-containing material is cooled. Re-heat treatment (hereinafter referred to as second heat treatment) is performed. The aluminum nitride is cooled by, for example, furnace cooling. The second heat treatment is performed using, for example, the carbon resistance furnace used in the first heat treatment. By performing the second heat treatment, the nitriding reaction of aluminum contained in the aluminum nitride-containing material proceeds, the aluminum content decreases, and the aluminum nitride content increases.

  In the present embodiment, the second heat treatment may be performed under conditions that facilitate the nitriding reaction of aluminum as compared with the first heat treatment, or may be substantially the same as the heat treatment conditions in the first heat treatment. Specifically, when the heat treatment temperature in the first heat treatment is 700 ° C. or more and 1400 ° C. or less, the heat treatment temperature in the second heat treatment is 700 ° C. or more and 1400 ° C. or less. Further, the pressure of the nitrogen gas atmosphere in the second heat treatment is, for example, a pressurized atmosphere, but may be a normal pressure or a reduced pressure atmosphere as in the first heat treatment.

  Also in the second heat treatment, the rate of aluminum nitride contained in the aluminum nitride-containing product, which is the product, is adjusted by changing the processing conditions (specifically, temperature and pressure) to adjust the progress rate of the aluminum nitride production reaction. And the proportion of aluminum can be lowered. If the nitriding reaction of aluminum proceeds excessively, the aluminum nitride-containing material becomes a mixture of an aggregated (bulk) material and a powder material, and further a powder. The powdered product is high purity aluminum nitride.

  Further, the second heat treatment, that is, the cooling and heating cycle of the aluminum nitride-containing material may be performed a plurality of times. As a result, the aluminum content is further reduced and the aluminum nitride content is further increased even at low temperature (eg, 1100 ° C.) and low pressure (eg, 15 atm). In addition, the aluminum nitride content can be increased as compared with the case where the heat treatment time is simply increased.

  Also in this embodiment, a massive aluminum nitride-containing material can be easily obtained. The characteristics of the obtained aluminum nitride-containing material vary depending on the proportion of aluminum. For example, when the proportion of aluminum is high, the workability of the aluminum nitride-containing material is improved, and when the proportion of aluminum is low, the characteristics of the aluminum nitride-containing material are close to those of AlN. Moreover, since the surfaces of the aluminum nitride particles are covered with aluminum, good moisture resistance can be obtained.

  In addition, the manufacturing conditions are low temperature and low pressure as compared with the conventional method. Therefore, the manufacturing cost is significantly reduced as compared with the conventional one. Moreover, powdery aluminum nitride can be manufactured by adjusting manufacturing conditions. Even in this case, the manufacturing conditions are low temperature and low pressure as compared with the conventional case, and the manufacturing cost is significantly reduced as compared with the conventional case.

  Further, the second heat treatment may be performed after the shape of the massive aluminum nitride-containing material after the first heat treatment is processed into a desired shape (for example, a heat dissipation substrate, a piston, or a cylinder). In particular, when the Al content in the aluminum nitride-containing material after the first heat treatment is, for example, 40 to 70%, the workability of the aluminum nitride-containing material is improved. Also in this case, the aluminum nitride content of the aluminum nitride-containing material after shape processing can be increased (for example, 98% or more) by the second heat treatment.

  Further, by adjusting the conditions of the first heat treatment and the second heat treatment, the thermal expansion coefficient can be adjusted by adjusting the contents of aluminum nitride and aluminum in the aluminum nitride-containing material. For this reason, when using aluminum nitride-containing materials as heat sinks for semiconductor devices, the thermal expansion coefficient of the aluminum nitride-containing materials is easily matched to the thermal expansion coefficient of the substrate of the semiconductor device (for example, both the Si substrate and the compound semiconductor substrate). Can be made.

  FIG. 2 is a schematic view for explaining the method for producing an aluminum nitride-containing material according to the third embodiment. Hereinafter, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  First, a plate-like or massive aluminum piece 21 (for example, a disc-like aluminum having a diameter approximately the same as the inner diameter of the container 12) and a powder-like or particulate catalyst element-containing material 22 are put into the container 12. There may be one aluminum piece 21 or a plurality of pieces. The catalyst element-containing material 22 is a substance (for example, nitride) containing an element having a higher standard free energy of formation than aluminum nitride. Specific examples of this element are the same as those in the first embodiment. The catalyst element containing material 22 is, for example, silicon nitride, but may be a mixture of silicon nitride and boron nitride, calcium nitride (CaN), gallium nitride (GaN), hafnium nitride (HfN), thorium nitride (ThN). ) And any one or more of the group consisting of vanadium nitride (VN) may be used. At this time, the catalyst element-containing material 22 is positioned below the aluminum piece 21. The catalyst element-containing material 22 is preferably dispersed substantially uniformly on the front surface. The weight ratio of the catalyst element-containing material 22 to aluminum is preferably 0.1 or more and 1 or less.

  Further, before putting the aluminum piece 21 and the catalyst element containing material 22 into the container 12, the catalyst element containing material 22 is pressed on one surface of the aluminum piece 21 so that the catalytic element is almost entirely on the one surface. It is preferable that the inclusion 22 is adhered substantially evenly and this one surface is directed downward.

  Further, inside the container 12, a plurality of aluminum pieces 21 are stacked while sandwiching the powder or particles of the catalyst element-containing material 22 between them, and the lowermost aluminum piece 21 is the powder of the catalyst element-containing material 22. Or you may arrange | position on particle | grains. Even in this case, it is preferable that the catalyst element-containing material 22 in the form of powder or particles is attached substantially uniformly to one surface of the aluminum piece 21 and this one surface is directed downward.

  Next, the inside of the reaction chamber 10 is exhausted from the exhaust port described above, and then nitrogen gas is introduced from the gas inlet 11. Thereby, the inside of the reaction chamber 10 becomes a nitrogen atmosphere. The pressure of the nitrogen gas inside the reaction chamber 10 may be a normal pressure or a reduced pressure atmosphere, or a pressurized atmosphere (for example, 5 to 30 atm, particularly preferably 9 to 11 atm).

  Next, the container 12 is heated with the heater 13, and the inside of the container 12 is heated to a melting point of aluminum (660 ° C.) or higher, preferably 900 ° C. to 1300 ° C. (particularly preferably 1010 ° C. to 1020 ° C.). As a result, the aluminum piece 21 in the container 12 is melted, a solid-liquid two-phase reaction occurs between the molten aluminum piece 21 and the solid catalyst element-containing material 22, and nitrogen in the atmosphere is added to the reaction. Thus, an aluminum nitride-containing material and slag are formed.

When the catalyst element-containing material 22 is positioned below the aluminum piece 21 inside the container 12, the molten aluminum piece 21 penetrates between the powdered catalyst element-containing material 22, and the catalyst element-containing material 22 is caused by buoyancy. Float in molten aluminum. For this reason, the formation reaction of aluminum nitride proceeds efficiently. Further, since aluminum nitride has a higher specific gravity than aluminum, the produced aluminum nitride is precipitated, and the nitriding reaction of aluminum proceeds above the aluminum nitride. When the catalytic element-containing material 22 is deposited substantially uniformly on one surface of the aluminum piece 21, the above-described solid-liquid two-phase reaction growth nuclei are generated in an extremely large number and evenly, so that aluminum nitride is generated substantially uniformly.
The speed at which this nitriding reaction proceeds can be controlled by the processing temperature and the pressure of atmospheric nitrogen, as in the first embodiment.

  Next, if necessary, the obtained aluminum nitride-containing material is subjected to a second heat treatment by the same method as in the second embodiment. By this treatment, the nuclei of aluminum nitride grew sufficiently in the aluminum nitride-containing material and joined together to form a network (percolation structure), and aluminum was dispersed independently in an island shape between the networks. It becomes a state. For this reason, the insulation of an aluminum nitride containing material becomes high.

  When the catalytic element-containing material 22 is adhered substantially uniformly on one surface of the aluminum piece 21, as described above, in the first heat treatment, the growth nuclei of the solid-liquid two-phase reaction are very many and evenly generated. In this case, since these growth nuclei serve as reaction starting points, the nitriding reaction of aluminum also proceeds substantially uniformly throughout the aluminum nitride-containing material by the second heat treatment, and in particular, aluminum is easily dispersed in an island shape.

  Also in this embodiment, the second heat treatment may be performed after processing the massive aluminum nitride-containing material after the first heat treatment into a desired shape (for example, a heat sink, piston, or cylinder of a semiconductor device). . Further, the second heat treatment, that is, the cooling and heating cycle of the aluminum nitride-containing material may be performed a plurality of times. In each of the first heat treatment and the second heat treatment described above, the heat treatment temperature may be changed depending on the grain size of the nitride.

  As described above, also according to this embodiment, the same effect as that of the first embodiment can be obtained.

  Next, the manufacturing method of the aluminum nitride containing material which concerns on 4th Embodiment is demonstrated. The present embodiment is the same as the third embodiment except that the arrangement density of the catalyst element-containing material 22 inside the container 12 is changed, for example, in the cross-sectional direction of the container 12 inside the container 12. . Specifically, for example, the arrangement density of the catalyst element-containing material 22 in the periphery of the container 12 is higher than the arrangement density of the catalyst element-containing material 22 in the center of the container 12.

Also in this embodiment, the same effect as that of the first embodiment can be obtained.
Further, the growth nuclei of the solid-liquid two-phase reaction generated between the molten aluminum piece 21 and the solid catalyst element-containing material 22 have a higher density in the periphery of the container 12 than in the center. For this reason, in the produced | generated aluminum nitride containing material, aluminum content rate can be made to incline in a cross-sectional direction, for example. Specifically, the island-like aluminum content in the peripheral portion of the aluminum nitride-containing material can be made lower than the island-like aluminum content in the central portion. In this case, for example, a portion having a high aluminum content in the aluminum nitride-containing material can be used as a bonding region for bonding to a semiconductor device or the like. Moreover, a cavity structure can be easily formed by eluting aluminum contained in the aluminum nitride-containing material with a chemical solution (for example, a sodium hydroxide aqueous solution).

  Next, the manufacturing method of the aluminum nitride containing material which concerns on 5th Embodiment is demonstrated. In this embodiment, in at least one of the first heat treatment and the second heat treatment, a temperature gradient is generated inside the container 12, for example, the temperature at the periphery of the container 12 is 50 ° C. from the temperature at the center of the container 12. Except for the point that the temperature is raised by 300 ° C. or less, the second embodiment or the third embodiment is the same.

  Also in the present invention, a gradient occurs in the reaction speed of the solid-liquid two-phase reaction that occurs between the molten aluminum piece 21 and the catalyst element-containing material 22 in the solid phase. For example, the peripheral portion of the container 12 is faster than the central portion. Become. For this reason, the aluminum content rate of the produced | generated aluminum nitride containing material can be made to incline. For example, the content of island-shaped aluminum in the peripheral portion of the aluminum nitride-containing material can be made lower than the content of island-shaped aluminum in the central portion. That is, the same effect as the second embodiment can be obtained.

  Next, the manufacturing method of the aluminum nitride containing material which concerns on 6th Embodiment is demonstrated. In the present embodiment, in at least one of the first heat treatment and the second heat treatment, the heater 13 that heats the container 12 is reciprocated up and down around the container 12, and the aluminum piece 21 or the aluminum in the aluminum nitride-containing material is moved. It is the same as that of 2nd Embodiment or 3rd Embodiment except for making it melt | dissolve partially and moving this melt | dissolving part up and down.

  In the present embodiment, a plurality of heaters 13 may be arranged vertically spaced apart. Further, it is preferable that a plurality of aluminum pieces 21 are laminated while sandwiching silicon nitride powder or particles therebetween, and the lowermost aluminum piece 21 is arranged on the silicon nitride powder or particles.

  According to the present embodiment, the nitriding reaction of aluminum is an exothermic reaction. However, according to the present embodiment, the aluminum nitride-containing material is heated periodically, so that the temperature of the aluminum nitride-containing material is made uniform. Easy to keep. For this reason, when manufacturing the ingot of the aluminum nitride containing material of vertically long (for example, cylindrical shape), the uniformity of the material of an ingot can be improved. Moreover, the heat history of the same direction can be given to aluminum nitride containing material in multiple times. Therefore, the crystal growth direction of the aluminum nitride-containing material can be improved by aligning the crystal growth directions of the aluminum nitride-containing material in substantially the same direction.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, a cooling means may be provided in the heater 13 to increase the cooling rate of the heater 13 and the aluminum nitride-containing material.

  In each of the above-described embodiments, the heater 13 of the reaction apparatus may be formed in a plate shape (for example, a disk shape) and disposed above, below, or both above and below the container 12. In this way, when the aluminum nitride-containing material in the container 12 is thin and plate-shaped, the uniformity of the material of the aluminum nitride-containing material can be improved. Moreover, when the aluminum nitride containing material in the container 12 is vertically long, a temperature gradient in the vertical direction can be given, and the aluminum content of the produced aluminum nitride containing material can be inclined in the vertical direction. Even in this case, the heater 13 may be provided with a cooling means.

The block diagram of the reactor used for the manufacturing method of the aluminum nitride containing material which concerns on 1st and 2nd embodiment. Schematic for demonstrating the manufacturing method of the aluminum nitride containing material which concerns on 3rd Embodiment.

Explanation of symbols

10 ... Reaction chamber 11 ... Gas inlet 12 ... Crucible (reaction vessel)
DESCRIPTION OF SYMBOLS 13 ... Graphite heater 14 ... Thermocouple monitor line 20 ... Aluminum containing catalytic element 21 ... Aluminum piece 22 ... Material containing catalytic element

Claims (22)

  By positioning a catalytic element, which is an element having a free energy of formation of nitride smaller than aluminum, in molten aluminum heated in a nitrogen atmosphere, an nitriding reaction of aluminum using the catalytic element as a catalyst occurs, and aluminum nitride The manufacturing method of the aluminum nitride containing material which comprises the 1st heat treatment process which produces | generates the aluminum nitride containing material containing this.   2. The nitriding according to claim 1, wherein the catalytic element is at least one selected from the group consisting of boron, calcium, silicon, iron, molybdenum, chromium, vanadium, magnesium, manganese, indium, gallium, tantalum, hafnium, and thorium. A method for producing an aluminum-containing material.   Catalyst element solid solution aluminum which is aluminum in which the catalyst element is solid solution, Catalyst element compound aluminum which is aluminum which forms a compound with the catalyst element, Mixture of catalyst element solid solution aluminum and catalyst element compound aluminum Or at least one of the catalytic element solid solution aluminum and the catalytic element compound aluminum and a mixture of aluminum are melted in a nitrogen atmosphere so that the catalytic element is located in the molten aluminum in a nitrogen atmosphere. The manufacturing method of the aluminum nitride containing material as described in 2.   The catalyst element is located in the molten aluminum by heating the substance containing the catalyst element and the aluminum in the same container to melt the aluminum. The manufacturing method of the aluminum nitride containing material as described in 2.   The manufacturing method of the aluminum nitride containing material of Claim 4 which arrange | positions the said aluminum on the substance containing the said catalyst element in the said container, and melt | dissolves the said aluminum after that. The aluminum is in the form of a plate or a lump, and the substance containing the catalytic element is in the form of powder or particles,
6. The powder or particles of the substance containing the catalytic element are attached to one surface of the aluminum, and then the aluminum is disposed on the substance containing the catalytic element with the one surface facing downward. A method for producing an aluminum nitride-containing material. The aluminum is in the form of a plate or a lump, and the substance containing the catalytic element is in the form of powder or particles,
By pressing the powder or particles of the substance containing the catalyst element on one surface of each of the plurality of aluminum, the powder or particles of the substance containing the catalyst element are attached to each of the one surface of the plurality of aluminum,
The plurality of aluminum layers are stacked in the container with the powder or particles of the substance containing the catalytic element sandwiched therebetween with the one surface facing downward, and the lowermost aluminum layer is The manufacturing method of the aluminum nitride containing material of Claim 5 arrange | positioned on the powder or particle | grains of the substance containing the said catalyst element.   In the first heat treatment step, the arrangement density of the powder or particles of the substance containing the catalytic element in the peripheral part of the container is more than the arrangement density of the powder or particles of the substance containing the catalytic element in the central part of the container. The manufacturing method of the aluminum nitride containing material as described in any one of Claims 4-7 made high.   The manufacturing method of the aluminum nitride containing material as described in any one of Claims 1-8 which makes the heat processing temperature in a said 1st heat processing process 700 degreeC or more and 1400 degrees C or less.   The method for producing an aluminum nitride-containing material according to claim 1, wherein the nitrogen gas atmosphere is a pressurized atmosphere in the first heat treatment step.   The said nitrogen gas atmosphere is 50 atmospheres or less, The manufacturing method of the aluminum nitride containing material of Claim 10.   In the said 1st heat treatment process, the manufacturing method of the aluminum nitride containing material as described in any one of Claims 1-9 which makes the said nitrogen gas atmosphere a normal pressure.   The said 1st heat treatment process WHEREIN: After cooling the said aluminum nitride containing material, it comprises the 2nd heat treatment process of heat-treating the said aluminum nitride containing material again in nitrogen atmosphere. A method for producing an aluminum nitride-containing material.   The method for producing an aluminum nitride-containing material according to claim 13, further comprising a step of processing the shape of the aluminum nitride-containing material between the first heat treatment step and the second heat treatment step.   The method for producing an aluminum nitride-containing material according to claim 13 or 14, wherein in the second heat treatment step, the nitrogen atmosphere is a pressurized atmosphere.   The method for producing an aluminum nitride-containing material according to claim 15, wherein the nitrogen atmosphere in the second heat treatment step is 50 atm or less.   The method for producing an aluminum nitride-containing material according to claim 13 or 14, wherein, in the second heat treatment step, the nitrogen gas atmosphere is set to normal pressure.   The method for producing an aluminum nitride-containing material according to any one of claims 13 to 17, wherein the second heat treatment step is repeated a plurality of times.   The aluminum nitride-containing material according to any one of claims 1 to 18, wherein in the first heat treatment step, the temperature of the peripheral portion of the molten aluminum is set to be 50 ° C or higher and 300 ° C or lower higher than the temperature of the central portion of the molten aluminum. Manufacturing method.   The aluminum nitride according to any one of claims 1 to 19, wherein, in the first heat treatment step, a relative position of a heating means for heating the molten aluminum with respect to the molten aluminum is reciprocated up and down around the molten aluminum. Method for producing inclusions.   An aluminum nitride-containing material in which aluminum is dispersed in an island shape in massive aluminum nitride and silicon is present in a state where silicon is dispersed in at least a part of the grain boundary between aluminum and aluminum nitride.   The aluminum nitride-containing material according to claim 21, wherein a dispersion density of the aluminum is inclined.

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