| 摘要 |
PROBLEM TO BE SOLVED: To more precisely suppress the deterioration in the crystallinity of a body part of a sapphire ingot and entrainment of bubbles in the body part when a sapphire single crystal is crystal-grown from a melt of aluminum oxide.SOLUTION: A method for producing a sapphire single crystal includes: a melting process for melting, by heating, an aluminum oxide of a solid filled in a crucible in a heating furnace; a seeding process for bringing the lower end of a seed crystal into contact with the melt of aluminum oxide, that is, an alumina melt; a shoulder formation process including a bubble taking process for forming a shoulder part under the seed crystal and taking bubbles that float on the alumina melt in the shoulder part by pulling upward the seed crystal while stopping or rotating in a state that the lower end of the seed crystal is in contact with the alumina melt; and a body part formation process for forming the body part under the shoulder part by pulling upward the seed crystal while rotating the shoulder part through the seed crystal in a state that the lower end of the shoulder part is in contact with the alumina melt. |
