Method and equipment for producing sapphire single crystal

摘要

The method can produce a sapphire single crystal without forming cracks and without using an expensive crucible. The method comprises: putting a seed crystal (24) and a raw material (26) in a crucible (20); heating the crucible (20) by a cylindrical heater (14); and producing temperature gradient in the cylindrical heater (14) to sequentially crystallize a melt. The crucible (20) is composed of a material having a specific linear expansion coefficient which is capable of preventing mutual stress, which is caused by a difference between a linear expansion coefficient of the crucible (20) and that of the sapphire single crystal in a direction perpendicular to a growth axis, from generating in the crucible (20) and the sapphire single crystal, or which is capable of preventing deformation of the crucible (20) without generating a crystal defect caused by the mutual stress.