CRUCIBLE FOR GROWING SAPPHIRE SINGLE CRYSTAL

• Main Authors: OKANO KATSUHIKO, SHIMIZU JUICHI, SHO YOSHIHIKO
• Format: Patent
• Language: English
• Published: 29.09.2014
• Subjects: AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUSPOLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR; CHEMISTRY; CRYSTAL GROWTH; METALLURGY; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; REFINING BY ZONE-MELTING OF MATERIAL; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; SINGLE-CRYSTAL-GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL ORUNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL

PROBLEM TO BE SOLVED: To provide a low-cost crucible for growing a sapphire single crystal, which is a crucible used for growing the sapphire single crystal using a Bridgman method or a VGF method and allows taking-out of the sapphire single crystal from the crucible after growth without breaking the crucible.SOLUTION: Among inner peripheral surfaces of a crucible 1 made of tungsten or a tungsten alloy, an adhesion preventive layer 7 is formed at least on a part which contacts an upper surface of a sapphire raw material solution 5 during growing of a sapphire single crystal. The adhesion preventive layer consists of an alloy including the tungsten or a component consisting of the tungsten alloy and 5 mass% or more of a metal M (M is one or more elements selected form Pt, Pd, Re, Rh, or Ir). The surface of the adhesion preventive layer has a tungsten content of 20 mass% or more, a metal M content of 20 mass% or more, and the thickness is in the range of 0.05-50 μm.