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Method for Growing High-Quality Group III-Nitride Crystals
Technology Benefits
Allows the production of high-quality group III-nitride crystals Impurities are prevented from being incorporated into grown crystals Lower production costs (source materials and nutrients can be recycled)
Technology Application
Production of group III-nitride crystals This technology is available for a non-exclusive license.
Detailed Technology Description
Researchers at the University of California, Santa Barbara have developed a novel method for growing group Ill-nitride crystals in supercritical ammonia. The group III-nitride bulk crystal is grown in an autoclave in supercritical ammonia using a source material or nutrient and a seed crystal. The supercritical ammonia provides for high solubility of the source materials and high transport speed of dissolved precursors. This method uses an internal chamber equipped with a pressure releasing device that enables the safe filling of ammonia and an exact balancing of the pressure inside and outside the internal chamber. The present invention suppresses the generation of particles from the source material and prevents the adhesion of the particles from the source material on the seed crystals. Thus, this invention produces high quality group III-nitride crystals and reduces production costs, since the source materials and nutrients are recyclable.
Supplementary Information
Patent Number: US8709371B2 Application Number: US2007921396A Inventor: Fujito, Kenji | Hashimoto, Tadao | Nakamura, Shuji Priority Date: 8 Jul 2005 Priority Number: US8709371B2 Application Date: 30 Nov 2007 Publication Date: 29 Apr 2014 IPC Current: C01B002106 | C30B002300 | C30B002500 | C30B002812 | C30B002814 US Class: 423409 | 117084 Assignee Applicant: The Regents of the University of California | Japan Science and Technology Agency,Kawaguchi, Saitama Prefecture Title: Method for growing group III-nitride crystals in supercritical ammonia using an autoclave Usefulness: Method for growing group III-nitride crystals in supercritical ammonia using an autoclave Summary: For growing group III-nitride (e.g. gallium nitride) crystals (claimed). Novelty: Growing group III-nitride e.g. gallium nitride crystals involves raising temperature so that convection of supercritical ammonia deposits only transferred source materials of specific grain size on seed crystals
Industry
Chemical/Material
Sub Group
Chemical/Material Application
Application No.
8709371
Others
Background
The growth of a bulk crystal of a group III-nitride (such as GaN, AlN, and LiN) presents some difficulties, since group III-nitrides have a high melting point and high nitrogen vapor pressure at high temperature. Some methods, such as high-pressure high-temperature synthesis and sodium flux, have been used to obtain bulk group III-nitride crystals. However, the crystal shape obtained by these methods is a thin platelet because these methods are based on a melt of group III metal, in which nitrogen has very low solubility and a low diffusion coefficient.
