| 摘要 |
PROBLEM TO BE SOLVED: To produce a large-diameter, lengthy and high-quality sapphire single crystal by c-axis pulling-up.SOLUTION: In production of a sapphire single crystal, a c-axis sapphire seed crystal is dipped into an alumina melt in a crucible, and the seed crystal is pulled up, while being rotated, to be thereby grown in the c-axix direction, In this case, crystal growth of the seed crystal is progressed under the liquid surface of the alumina melt, and the seed crystal is pulled up at prescribed pulling speed so that an in-liquid growth part of the seed crystal does not reach the bottom surface of the crucible. At that time, pulling is controlled so that a side face shape of the in-liquid growth part has an approximate V-shape projected in the downward direction. |
