Process for large-scale ammonothermal manufacturing of gallium nitride boules

A method for growth of an m-plane gallium-containing nitride crystal, the method comprising:

• providing a gallium-containing source material;
• providing a mineralizer;
• providing at least 25 gallium-containing nitride seed plates, each of the at least 25 gallium-containing nitride seed plates comprising a first large-area surface and a second large-area surface opposite the first large-area surface, wherein,
• each of the first large-area surfaces and each of the second large-area surfaces are characterized by a minimum lateral dimension of at least about three centimeters;
• the first large-area surface of the first gallium-containing nitride seed plate comprises an outward facing growth surface characterized by a first crystallographic orientation;
• the first large-area surface of the second gallium-containing nitride seed plate comprises an outward facing growth surface characterized by a second crystallographic orientation;
• the first crystallographic orientation and the second crystallographic orientation differ by at least about 0.1 degree and less than about 5 degrees;
• and
• the first crystallographic orientation and the second crystallographic orientation are characterized by a nominally m-plane crystallographic orientation with a miscut angle in the c-direction between about 5 degrees and about 0.05 degrees toward [000−1] and a miscut angle in the a-direction less than or equal to about 1 degree;
• supporting the at least two seed plates in a seed rack;
• placing the source material, the mineralizer, and the seed rack supporting the at least two seed plates in a sealable container;
• introducing a nitrogen-containing solvent into the sealable container;
• and
• processing the source material, the mineralizer, and the at least two seed plates contained in the sealable container in a supercritical fluid at a temperature higher than about 400 degrees Celsius to provide at least 25 m-plane gallium-containing nitride crystals, wherein,
• a surface of each of the at least 25 m-plane gallium-containing nitride crystals is characterized by an X-ray diffraction rocking curve full-width-half maximum less than about 150 arc-second.

A method for growth of a plurality of gallium-containing nitride crystals, the method comprising:

• providing a gallium-containing source material;
• providing a mineralizer;
• providing a plurality of gallium-containing nitride seed plates, each of the plurality of seed plates having a non-cubic crystal structure and a wedge shape, wherein the wedge shape comprises a wedge angle θ between a first large area surface and a second large area surface between about 1 degree and about 60 degrees, wherein the first large area surface and the second large area surface have crystallographic orientations that are equivalent to one another to within about 5 degrees;
• supporting the plurality of seed plates in a seed rack, wherein the seed rack is substantially rigid under processing conditions;
• placing the source material, the mineralizer, and the seed rack supporting the plurality of seed plates in a sealable container;
• introducing a nitrogen-containing solvent into the sealable container;
• and
• processing the source material, the mineralizer, and the plurality of gallium-containing nitride seed plates contained in the sealable container in a supercritical fluid at a temperature higher than about 400 degrees Celsius to provide a plurality of gallium-containing nitride crystals.