Abstract: The purpose of the present invention is to provide a method for synthesizing ammonia and an apparatus for the method. The method for synthesizing ammonia according to the present invention comprises: a step of melting a metal containing at least an alkali metal; and a step of supplying a hydrogen gas and a nitrogen gas to the molten metal.

Abstract: The purpose of the present invention is to provide a method for synthesizing ammonia and an apparatus for the method. The method for synthesizing ammonia according to the present invention comprises: a step of melting a metal containing at least an alkali metal; and a step of supplying a hydrogen gas and a nitrogen gas to the molten metal.

Abstract: The purpose of the present invention is to provide a method for synthesizing ammonia and an apparatus for the method. The method for synthesizing ammonia according to the present invention comprises: a step of melting a metal containing at least an alkali metal; and a step of supplying a hydrogen gas and a nitrogen gas to the molten metal.

Abstract: The present invention addresses the problem of providing a method for synthesizing hexagonal tungsten nitride by synthesizing hexagonal tungsten nitride as a main product, and of providing the hexagonal tungsten nitride. The problem is solved through use of a method for synthesizing hexagonal tungsten nitride comprising synthesizing hexagonal tungsten nitride by heating a starting material powder containing a tungsten halide and an alkali metal nitride and/or an alkaline earth metal nitride.

Abstract: The present invention addresses the problem of providing a method for synthesizing hexagonal tungsten nitride by synthesizing hexagonal tungsten nitride as a main product, and of providing the hexagonal tungsten nitride. The problem is solved through use of a method for synthesizing hexagonal tungsten nitride comprising synthesizing hexagonal tungsten nitride by heating a starting material powder containing a tungsten halide and an alkali metal nitride and/or an alkaline earth metal nitride.

Abstract: The apparatus has a crucible for storing a solution; an inner container for storing a crucible; a heating container for storing the inner container, the heating container including heating elements, a container body provided with the heating elements and a lid combined with the container body; and a pressure vessel for storing the heating container and for charging an atmosphere comprising at least nitrogen gas. The lid also has a fitting surface to the container body that is inclined to a horizontal plane.

Abstract: A growth apparatus is used having a plurality of crucibles each for containing the solution, a heating element for heating the crucible, and a pressure vessel for containing at least the crucibles and the heating element and for filling an atmosphere comprising at least nitrogen gas. One seed crystal is put in each of the crucibles to grow the nitride single crystal on the seed crystal.

Abstract: It is provided a melt composition for growing a gallium nitride single crystal by flux method. The melt composition contains gallium, sodium and barium, and a content of barium is 0.05 to 0.3 mol % with respect to 100 mol % of sodium.

Abstract: A method for producing a high-quality group-III element nitride crystal at a high crystal growth rate, and a group-III element nitride crystal are provided. The method includes the steps of placing a group-III element, an alkali metal, and a seed crystal of group-III element nitride in a crystal growth vessel, pressurizing and heating the crystal growth vessel in an atmosphere of nitrogen-containing gas, and causing the group-III element and nitrogen to react with each other in a melt of the group-III element, the alkali metal and the nitrogen so that a group-III element nitride crystal is grown using the seed crystal as a nucleus. A hydrocarbon having a boiling point higher than the melting point of the alkali metal is added before the pressurization and heating of the crystal growth vessel.

Abstract: A method for producing a high-quality group-III element nitride crystal at a high crystal growth rate, and a group-III element nitride crystal are provided. The method includes the steps of placing a group-III element, an alkali metal, and a seed crystal of group-III element nitride in a crystal growth vessel, pressurizing and heating the crystal growth vessel in an atmosphere of nitrogen-containing gas, and causing the group-III element and nitrogen to react with each other in a melt of the group-III element, the alkali metal and the nitrogen so that a group-III element nitride crystal is grown using the seed crystal as a nucleus. A hydrocarbon having a boiling point higher than the melting point of the alkali metal is added before the pressurization and heating of the crystal growth vessel.

Abstract: A nitride single crystal is produced on a seed crystal substrate 5 in a melt containing a flux and a raw material of the single crystal in a growing vessel 1. The melt 2 in the growing vessel 1 has temperature gradient in a horizontal direction. In growing a nitride single crystal by flux method, adhesion of inferior crystals onto the single crystal is prevented and the film thickness of the single crystal is made constant.

Abstract: A raw material mixture containing an easily oxidizable material is weighed. The raw material mixture is melted and then solidified within a reaction vessel 1 set in a non-oxidizing atmosphere to thereby produce a solidified matter 19. The reaction vessel 1 and the solidified matter 19 are heated in a non-oxidizing atmosphere within a crystal growth apparatus to melt the solidified matter to thereby produce a solution. A single crystal is grown from the solution.

Abstract: In the production of GaN through the flux method, deposition of miscellaneous crystals on the nitrogen-face of a GaN self-standing substrate and waste of raw materials are prevented. Four arrangements of crucibles and a GaN self-standing substrate are exemplified. In FIG. 1A, a nitrogen-face of a self-standing substrate comes into close contact with a sloped flat inner wall of a crucible. In FIG. 1B, a nitrogen-face of a self-standing substrate comes into close contact with a horizontally facing flat inner wall of a crucible, and the substrate is fixed by means of a jig. In FIG. 1C, a jig is provided on a flat bottom of a crucible, and two GaN self-standing substrates are fixed by means of the jig so that the nitrogen-faces of the substrates come into close contact with each other. In FIG. 1D, a jig is provided on a flat bottom of a crucible, and a GaN self-standing substrate is fixed on the jig so that the nitrogen-face of the substrate is covered with the jig.

Abstract: It is disclosed an apparatus for growing a nitride single crystal using a flux containing an easily oxidizable substance. The apparatus has a crucible for storing the flux; a pressure vessel for storing the crucible and charging an atmosphere containing at least nitrogen gas; furnace materials disposed within the pressure vessel and out of the crucible; heaters attached to the furnace material; and alkali-resistant and heat-resistant metallic layers covering the furnace material.

Abstract: A GaN single crystal 20 is grown on a crystal growth surface of a seed crystal (GaN layer 13) through the flux method in a nitrogen (N2) atmosphere at 3.7 MPa and 870° C. employing a flux mixture including Ga, Na, and Li at about 870° C. Since the back surface of the template 10 is R-plane of the sapphire substrate 11, the template 10 is readily corroded or dissolved in the flux mixture from the back surface thereof. Therefore, the template 10 is gradually dissolved or corroded from the back surface thereof, resulting in separation from the semiconductor or dissolution in the flux. When the GaN single crystal 20 is grown to a sufficient thickness, for example, about 500 ?m or more, the temperature of the crucible is maintained at 850° C. to 880° C., whereby the entirety of the sapphire substrate 11 is dissolved in the flux mixture.

Abstract: Objects of the invention are to further enhance crystallinity and crystallinity uniformity of a semiconductor crystal produced through the flux method, and to effectively enhance the production yield of the semiconductor crystal. The c-axis of a seed crystal including a GaN single-crystal layer is aligned in a horizontal direction (y-axis direction), one a-axis of the seed crystal is aligned in the vertical direction, and one m-axis is aligned in the x-axis direction. Thus, three contact points at which a supporting tool contacts the seed crystal are present on m-plane. The supporting tool has two supporting members, which extend in the vertical direction. One supporting member has an end part, which is inclined at 30° with respect to the horizontal plane ?. The reasons for supporting a seed crystal at m-plane thereof are that m-plane exhibits a crystal growth rate, which is lower than that of a-plane, and that desired crystal growth on c-plane is not inhibited.

Abstract: A method for producing a high-quality group-III element nitride crystal at a high crystal growth rate, and a group-III element nitride crystal are provided. The method includes the steps of placing a group-III element, an alkali metal, and a seed crystal of group-III element nitride in a crystal growth vessel, pressurizing and heating the crystal growth vessel in an atmosphere of nitrogen-containing gas, and causing the group-III element and nitrogen to react with each other in a melt of the group-III element, the alkali metal and the nitrogen so that a group-III element nitride crystal is grown using the seed crystal as a nucleus. A hydrocarbon having a boiling point higher than the melting point of the alkali metal is added before the pressurization and heating of the crystal growth vessel.

Abstract: A method for producing a GaN crystal capable of achieving at least one of the prevention of nucleation and the growth of a high-quality non-polar surface is provided. The production method of the present invention is a method for producing a GaN crystal in a melt containing at least an alkali metal and gallium, including an adjustment step of adjusting the carbon content of the melt, and a reaction step of causing the gallium and nitrogen to react with each other. According to the production method of the present invention, nucleation can be prevented, and as shown in FIG. 4, a non-polar surface can be grown.

Abstract: In the flux method, a source nitrogen gas is sufficiently heated before feeding to an Na—Ga mixture. The apparatus of the invention is provided for producing a group III nitride based compound semiconductor. The apparatus includes a reactor which maintains a group III metal and a metal differing from the group III metal in a molten state, a heating apparatus for heating the reactor, an outer vessel for accommodating the reactor and the heating apparatus, and a feed pipe for feeding a gas containing at least nitrogen from the outside of the outer vessel into the reactor. The feed pipe has a zone for being heated together with the reactor by means of the heating apparatus, wherein the zone is heated inside the outer vessel and outside the reactor.

Abstract: The present invention provides a method for producing a semiconductor substrate, the method including reacting nitrogen (N) with gallium (Ga), aluminum (Al), or indium (In), which are group III elements, in a flux mixture containing a plurality of metal elements selected from among alkali metals and alkaline earth metals, to thereby grow a group III nitride based compound semiconductor crystal. The group III nitride based compound semiconductor crystal is grown while the flux mixture and the group III element are mixed under stirring. At least a portion of a base substrate on which the group III nitride based compound semiconductor crystal is grown is formed of a flux-soluble material, and the flux-soluble material is dissolved in the flux mixture, at a temperature near the growth temperature of the group III nitride based compound semiconductor crystal, during the course of growth of the semiconductor crystal.