Ammonothermal process for bulk synthesis and growth of cubic GaN

A method of growing single-crystals of zinc-blende c-GaN, the method comprising the steps of:

• placing into a sealable container a gallium source, anhydrous ammonia, an acid mineralizer and a co-mineralizer to a fill factor level of from about 25-75%;
• sealing said container;
• heating a hot zone of said container to of from about 470 to about 520° C. for a sufficient period of time;
• and
• solubilizing, transporting and growing single-crystals of zinc-blend c-GaN until all said gallium source is dissolved;
• and
• wherein said container has a hot zone and a cool zone due to a temperature gradient within said container, and
• wherein said hot zone is positioned within an area occupied by contents of said container.

A method of manufacturing a substrate wafer of c-GaN for use in a semiconductor device, the method comprising the steps of:

• placing into a container a gallium source, anhydrous ammonia, an acid mineralizer and a co-mineralizer to a fill factor of from about 25-80%;
• sealing said container;
• heating said container,
• solubilizing, transporting and growing triangular prisms of zinc-blende c-GaN until all said gallium source is dissolved;
• cooling said container;
• collecting a seed of a triangular prism of c-GaN;
• and
• placing said seed of a triangular prism of c-GaN in a cool zone of a container;
• and
• repeating said steps of placing a gallium source, anhydrous ammonia, an acid mineralizer and a co-mineralizer in a container, sealing, heating, solubilizing, transporting, growing and placing a larger seed of a triangular prism of c-GaN in a container until a sufficiently large triangular prism of c-GaN is grown;
• and
• cutting the said triangular prism of c-GaN into wafers.
• wherein said containers have a hot zone and a cool zone due to a temperature gradient within said containers.

A method of growing single-crystals of a cubic (zinc blende) form of gallium nitride, the method comprising the steps of:

• placing into a reaction tube or acid resistant vessel a gallium source, anhydrous ammonia, NH4Cl, and LiCl;
• closing said reaction tube or vessel;
• heating said reaction tube;
• cooling said reaction tube or vessel;
• and
• collecting single-crystals of cubic (zinc blende) form of GaN;
• wherein said reaction tube or vessel has a temperature gradient with a hot zone of at least 250° C.,
• wherein said reaction tube or vessel has a temperature gradient with a cool zone of at least 150° C., and
• wherein said acid mineralizer has a sufficient concentration to permit chemical transport of GaN in said reaction tube or vessel from said hot zone to said cool zone due to said temperature gradient within said reaction tube or vessel.