Patent ID: 8449672

Claim:
A low temperature and pressure process for making Group III nitride crystals comprising the steps of: (a) charging a reaction vessel with a Group III nitride material source and a predetermined compound composition of lithium nitride and barium fluoride in contact therewith; (b) placing the charged reaction vessel into a chamber; (c) subjecting simultaneously the reaction vessel and the charge therein both to pressure and temperature; (d) maintaining the stoichiometry of the Group III nitride source material; (e) heating a reaction vessel to a temperature of the melting point of the predetermined compound composition of lithium nitride and barium fluoride to render the predetermined compound composition molten and creating a liquid salt-based solvent at a temperature below the melting point of either lithium nitride or barium fluoride, wherein said heating step is conducted in an atmosphere comprising a nitrogen containing gas at a pressure on the order of 1-100 atmospheres and wherein said heating step is carried out to a liquefaction temperature of the salt-based solvent and wherein a temperature difference is 1-100° C. across the salt-based solvent thickness and wherein the predetermined compound composition of lithium nitride and barium fluoride creates liquid solvent at a temperature of 730° C. and a pressure of 0.1 MPa; (f) maintaining the composition of the molten Group III nitride source material together with the lithium nitride and barium fluoride salt-based solvent; (g) disposing a Group III nitride seed crystal to the salt-based solvent whereby Group III nitride from the Group III nitride source precipitates on the Group III nitride seed crystal; and (h) dissolving the Group III nitride source and maintaining the heat, to transfer Group III nitride through the layer of the salt-based solvent, to create a supersaturated solution of Group III nitride first in a molten solvent in the hotter part of the reaction vessel, and then precipitated from the molten solvent to grow a single crystal in a cooler part of the reaction vessel.