# US 7,744,697 B2 · Bulk monocrystalline gallium nitride > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,744,697 B2 - Document ID: US7744697B2 - Status: Granted - Kind: B2 - Application number: 10/682,891 - Filed: 2003-10-14 - Published: 2004-05-13 - Granted: 2010-06-29 - Earliest claimed: 2001-06-06 - Assignees: Nichia Corporation; Ammono Sp. z o.o. - Inventors: Robert Tomasz Dwiliński; Roman Marek Doradziński; Jerzy Garczyński; Leszek Piotr Sierzputowski; Yasuo Kanbara - Web page: https://patentgrep.com/patent/US7744697B2 ## CPC - C30B 29/406: {Gallium nitride} - C30B 7/00: Single-crystal growth from solutions using solvents which are liquid at normal temperature, e.g. aqueous solutions (from molten solvents C30B9/00; by normal or gradient freezing C30B11/00; under a protective fluid C30B27/00) - C30B 7/10: by application of pressure, e.g. hydrothermal processes - C30B 29/403: {AIII-nitrides} - H01S 5/0281: {Coatings made of semiconductor materials} - H01S 5/32341: {blue laser based on GaN or GaP} - Y10T 117/10: Apparatus - Y10T 117/102: for forming a platelet shape or a small diameter, elongate, generally cylindrical shape [e.g., whisker, fiber, needle, filament] - Y10T 117/1024: for crystallization from liquid or supercritical state - C30B: SINGLE-CRYSTAL GROWTH (by using ultra-high pressure, e.g. for the formation of diamonds, B01J3/06); UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL (zone-refining of metals or alloys C22B); PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (casting of metals, casting of other substances by the same processes or devices B22D; working of plastics B29; modifying the physical structure of metals or alloys C21D, C22F); SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (for producing semiconductor devices or parts thereof H10); APPARATUS THEREFOR - H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract The present invention refers to an ammonobasic method for preparing a gallium-containing nitride crystal, in which gallium-containing feedstock is crystallized on at least one crystallization seed in the presence of an alkali metal-containing component in a supercritical nitrogen-containing solvent. The method can provide monocrystalline gallium-containing nitride crystals having a very high quality. ## Claims ### Claim 1 An apparatus for recrystallizing a gallium-containing nitride crystal on a seed in a supercritical state of a nitrogen-containing solvent containing an alkali metal component, comprising: an autoclave having an internal space provided with a device which separates the internal space into two zones, wherein the device which separates the internal space comprises at least one baffle having at least one opening, the at least one opening in the at least one baffle includes at least one of a central opening and a circumferential opening for keeping the nitrogen-containing solvent convection between the two zones; a first heating device disposed on an outer surface of the autoclave in a position corresponding to an upper zone of the autoclave; a second heating device disposed on an outer surface of the autoclave in a position corresponding to a lower zone of the autoclave; a cooling device disposed on an outer surface of the autoclave in a position between said first heating device and said second heating device; at least one temperature control device for controlling said first heating device, said second heating device and said cooling device to make a temperature profile in the autoclave; wherein the upper zone of the autoclave, which has a feedstock for the gallium-containing nitride is provided as a dissolution zone, while the lower zone of the autoclave, which has at least one crystallization seed for the gallium-containing nitride is provided as crystallization zone, wherein said first heating device and said second heating device are separated so said first heating device and said second heating device are spaced apart from a position corresponding to the device which separates the internal space; and wherein the lower zone of the autoclave is controlled at a higher temperature than the upper zone of the autoclave by using the at least one temperature control device. ### Claim 2 (depends on 1) The apparatus according to claim 1, wherein the temperature control device has an ability to make the upper zone of the autoclave controlled at a lower temperature than that of the lower zone according to a negative temperature coefficient of a solubility of the gallium-containing nitride crystal in the supercritical state of the nitrogen-containing solvent containing the alkali metal component. ### Claim 3 (depends on 1) The apparatus according to claim 1, wherein the feedstock comprises metallic gallium and gallium nitride. ### Claim 4 (depends on 1) The apparatus according to claim 1, wherein the feedstock further comprises an aluminum feedstock, an indium feedstock or mixtures thereof, which are selected from the group consisting of metallic aluminum, metallic indium, their alloys, their nitrides, azides, imides, amidoimides, and hydrides. ### Claim 5 (depends on 1) The apparatus according to claim 1, wherein the nitrogencontaining solvent comprises NH3. ### Claim 6 (depends on 1) The apparatus according to claim 1, wherein the seed has a surface of a compound represented by the general formula AlxGa1-x-yInyN, where 0