Abstract: A crystal growth apparatus comprises a reaction vessel holding a melt mixture containing an alkali metal and a group III metal, a gas supplying apparatus supplying a nitrogen source gas to a vessel space exposed to the melt mixture inside the reaction vessel, a heating unit heating the melt mixture to a crystal growth temperature, and a support unit supporting a seed crystal of a group III nitride crystal inside the melt mixture.

Abstract: A gallium nitride crystal having a hexagonal crystal structure includes a first region located on an inner side of a cross section intersecting c-axis of the hexagonal crystal structure, and a second region surrounding at least a part of the outer periphery of the first region in the cross section. An emission spectrum of each of the first region and the second region with electron beam or ultraviolet light excitation has a first peak including a band edge emission of gallium nitride and a second peak located in a longer wavelength area than the first peak. A peak intensity of the first peak is smaller than a peak intensity of the second peak in the first region, and a peak intensity of the first peak is greater than a peak intensity of the second peak in the second region.

Abstract: A group 13 nitride crystal has a hexagonal crystal structure and at least contains nitrogen atom and at least a kind of metal atoms selected from a group consisting of B, Al, Ga, In, and Tl. The group 13 nitride crystal includes a first region located at an inner side of a cross section intersecting a c-axis, and a second region surrounding at least a part of an outer periphery of the first region, having a thickness larger than a maximum diameter of the first region, and having a carrier density higher than that of the first region.

Abstract: A nitride crystal which encircles an outer periphery of a seed crystal, the nitride crystal in an embodiment includes: a first partial region, and a second partial region that has optical characteristics different from those of the first partial region and has optical characteristics which indicate the crystal orientation.

Abstract: A crystal has a diameter of 1 cm or more and shows a strongest peak in cathode luminescent spectrum at a wavelength of 360 nm in correspondence to a band edge.

Abstract: In a method of producing a group III nitride crystal in which a melt holding vessel where a melt containing a group III metal and flux is held is accommodated in a reaction vessel and a group III nitride crystal is produced as a substance containing nitrogen is supplied from an outside to the reaction vessel through a pipe, the method includes a step of forming an accumulated part of a liquid in the pipe to thereby temporarily close the pipe before growing the group III nitride crystal in the melt holding vessel.

Abstract: A group 13 nitride crystal of hexagonal crystal including at least one or more metal atom selected from the group consisting of B, Al, Ga, In, and Tl, and a nitrogen atom, the group 13 nitride crystal comprises: a first region provided on the inner side of a cross section crossing a c-axis; a third region provided on an outermost side of the cross section; a second region provided between the first region and the third region at the cross section and having characteristics different from characteristics of the first region and the third region, wherein a shape formed by a boundary between the first region and the second region at the cross section is non-hexagonal.

Abstract: A method for producing a group 13 nitride crystal, comprises a crystal growth step of reacting nitrogen and a mixed melt containing at least a group 13 metal and at least one of an alkali metal and an alkaline earth metal, in the mixed melt, to grow a nitride crystal on a seed crystal, wherein at least one of the mixed melt and the seed crystal is rotated in the crystal growth step, a relative speed between the mixed melt and the seed crystal in the crystal growth step is repeatedly fluctuated in accordance with one or a plurality of types of predetermined patterns, and a maximum value of the relative speed indicated by the pattern is 0.01 m/s or more.

Abstract: A crystal producing apparatus includes a crystal forming unit and a crystal growing unit. The crystal forming unit forms a first gallium nitride (GaN) crystal by supplying nitride gas into melt mixture containing metal sodium (Na) and metal gallium (Ga). The first GaN crystal is sliced and polished to form GaN wafers. The crystal growing unit grows a second GaN crystal on a substrate formed by using a GaN wafer, by the hydride vapor phase epitaxy method, thus producing a bulked GaN crystal.

Abstract: A group 13 nitride crystal having a hexagonal crystal structure contains at least a nitrogen atom and at least one metal atom selected from a group consisting of B, Al, Ga, In and Tl. Dislocation density of basal plane dislocations in a cross section parallel to a c-axis is 104 cm?2 or more.

Abstract: A crystal has a diameter of 1 cm or more and shows a strongest peak in cathode luminescent spectrum at a wavelength of 360 nm in correspondence to a band edge.

Abstract: A group-III nitride crystal growth method comprises the steps of: a) preparing a mixed molten liquid of an alkaline material and a substance at least containing a group-III metal; b) causing growth of a group-III nitride crystal from the mixed molten liquid prepared in the step a) and a substance at least containing nitrogen; and c) creating a state in which nitrogen can be introduced into the molten liquid prepared by the step a).

Abstract: A crystal growth method, comprising the steps of: a) bringing a nitrogen material into a reaction vessel in which a mixed molten liquid comprising an alkaline metal and a group-III metal; and b) growing a crystal of a group-III nitride using the mixed molten liquid and the nitrogen material brought in by the step a) in the reaction vessel, wherein a provision is made such as to prevent a vapor of the alkaline metal from dispersing out of the reaction vessel.

Abstract: A method is provided for producing a single crystal body of a group III nitride, comprising the steps of forming a molten flux of a volatile metal in a reaction vessel and causing a growth of a GaN single crystal from the molten flux, wherein the growth is continued while replenishing a compound containing N from a source outside the reaction vessel, and wherein a seed crystal is disposed in the reaction vessel.

Abstract: A crystal growth method, comprising the steps of: a) bringing a nitrogen material into a reaction vessel in which a mixed molten liquid comprising an alkaline metal and a group-III metal; and b) growing a crystal of a group-III nitride using the mixed molten liquid and the nitrogen material brought in by the step a) in the reaction vessel, wherein a provision is made such as to prevent a vapor of the alkaline metal from dispersing out of the reaction vessel.

Abstract: A group 13 nitride crystal has a hexagonal crystal structure containing a nitrogen atom and at least one type of metal atom selected from the group consisting of B, Al, Ga, In, and Tl. The group 13 nitride crystal has a basal plane dislocation in a plurality of directions. Dislocation density of the basal plane dislocation is higher than dislocation density of a threading dislocation of a c-plane.

Abstract: In a crystal preparing device, a crucible holds a mixed molten metal containing alkali metal and group III metal. A container has a container space contacting the mixed molten metal and holds a molten alkali metal between the container space and an outside of the container, the molten alkali metal contacting the container space. A gas supply device supplies nitrogen gas to the container space. A heating device heats the crucible to a crystal growth temperature. The crystal preparing device is provided so that a vapor pressure of the alkali metal which evaporates from the molten alkali metal is substantially equal to a vapor pressure of the alkali metal which evaporates from the mixed molten metal.

Abstract: A method for manufacturing a group III nitride crystal on a seed crystal in a holding vessel holding therein a melt containing a group III metal, an alkali metal and nitrogen. The manufacturing method comprises the steps of causing the seed crystal to make a contact with the melt, setting an environment of the seed crystal to a first state offset from a crystal growth condition while in a state in which said seed crystal is in contact with the melt, increasing a nitrogen concentration in the melt, and setting the environment of the seed crystal to a second state suitable for crystal growth when the nitrogen concentration of the melt has reached a concentration suitable for growing the seed crystal.

Abstract: A crystal producing apparatus includes a crystal forming unit and a crystal growing unit. The crystal forming unit forms a first gallium nitride (GaN) crystal by supplying nitride gas into melt mixture containing metal sodium (Na) and metal gallium (Ga). The first GaN crystal is sliced and polished to form GaN wafers. The crystal growing unit grows a second GaN crystal on a substrate formed by using a GaN wafer, by the hydride vapor phase epitaxy method, thus producing a bulked GaN crystal.

Abstract: A group 13 nitride crystal has a hexagonal crystal structure and at least contains nitrogen atom and at least a kind of metal atoms selected from a group consisting of B, Al, Ga, In, and Tl. The group 13 nitride crystal includes a first region located at an inner side of a cross section intersecting a c-axis, and a second region surrounding at least a part of an outer periphery of the first region, having a thickness larger than a maximum diameter of the first region, and having a carrier density higher than that of the first region.