High pressure high temperature growth of crystalline group III metal nitrides

A method of dissolving a source material for a Group III metal nitride in a flux material, the method comprising the steps of:

• a) providing the source material to a reaction vessel, wherein the source material comprises at least one Group III metal compound selected from the group consisting of compounds of aluminum, compounds of indium, and compounds of gallium, and wherein the reaction vessel is sealable with respect to nitrogen and is chemically inert;
• b) providing a flux material to the reaction vessel, wherein the flux material is a solid at about 30° C. and consists essentially of at least one of a nitride, an amide, a metal halide, urea, a derivative of urea, an ammonium salt, an alkaline earth fluoronitride, and combinations thereof;
• c) sealing the reaction vessel to provide a sealed reaction vessel comprising a reactant mixture consisting essentially of the source material provided in step a) and the flux material provided in step b);
• d) heating the reaction vessel to a predetermined temperature that is sufficient to decompose the Group III metal nitride and also applying a predetermined pressure to the vessel, wherein the predetermined pressure is sufficient to suppress decomposition of the Group III metal nitride at the predetermined temperature;
• e) melting the flux material;
• and
• f) dissolving at least a portion of the source material in the flux material.

A method of forming at least one single crystal of a Group III metal nitride, the method comprising the steps of:

• a) providing a source material to a reaction vessel, wherein the source material comprises at least one Group III metal selected from the group consisting of compounds of aluminum, compounds of indium, and compounds of gallium, and wherein the reaction vessel has an inner chamber and is sealable with respect to nitrogen and chemically inert;
• b) providing a flux material to the reaction vessel, wherein the flux material is a solid at about 30° C. and consists essentially of at least one of a nitride, an amide, a metal halide, urea, a derivative of urea, an ammonium salt, an alkaline earth fluoronitride, and combinations thereof, and wherein the flux material is capable of dissolving at least a portion of the source material;
• c) sealing the reaction vessel to provide a sealed reaction vessel comprising a reactant mixture consisting essentially of the source material provided in step a) and the flux material provided in step b);
• and heating a first end of the reaction vessel to a first temperature that is sufficient to decompose the Group III metal nitride, and heating a second end of the reaction vessel opposite the first end to a second temperature that is sufficient to decompose the Group III metal nitride;
• d) applying a predetermined pressure to the vessel, wherein the predetermined pressure is sufficient to suppress decomposition of the Group III metal nitride at the second temperature;
• e) melting the flux material;
• f) dissolving at least a portion of the source material in the flux material;
• and
• g) forming at least one single crystal of the Group III metal nitride in the second end of the reaction vessel.