LITHIUM GALLIUM OXIDE SINGLE CRYSTAL, SINGLE CRYSTAL SUBSTRATE AND THEIR PRODUCTION

• Main Authors: MIYAZAWA SHINTARO, TAZO YASUO, ISHII TAKAO
• Format: Patent
• Language: English
• Published: 08.12.1998
• Edition: 6
• Subjects: AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUSPOLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR; BASIC ELECTRIC ELEMENTS; CHEMISTRY; CRYSTAL GROWTH; DEVICES USING STIMULATED EMISSION; EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; FIXED CONSTRUCTIONS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; METALLURGY; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; REFINING BY ZONE-MELTING OF MATERIAL; SEMICONDUCTOR DEVICES; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; SINGLE-CRYSTAL-GROWTH; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ARTCOLLECTIONS [XRACs] AND DIGESTS; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL ORUNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL

PROBLEM TO BE SOLVED: To form a gallium nitride semiconductor epitaxial thin film free of a domain structure and reduced in transition on a lithium galate single crystal substrate by growing a single crystal with a seed crystal having a crystal axis at an angle of 30 deg. from the b axis direction at the time of pulling up and producing the lithium gallate single crystal by the Czochralski process and using the main surface as a c face. SOLUTION: A lithium gallate single crystal is pulled up at a deflection angle of 30 deg. from the b axis (010) direction and grown by the Czochralski process. A c face substrate is cut out from the obtained single crystal. The substrat is annealed, polished and etched to form a lithium gallate substrate with the surface as a single-domain c face (+c and -c regions are not coexistent). The substrate is irradiated with the nitrogen radical and gallium flux from a radical beam source, and a GaN thin film having an excellent characteristic as the light emitting element in a shot-wavelength region by molecular beam epitaxy. The thin films of InN and A/N are similarly formed.