| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a sapphire single crystal, capable of suppressing the occurrence of a crack when the sapphire single crystal is grown by placing a seed crystal on the bottom side of a crucible and solidifying a raw material melt from the seed crystal side under a temperature gradient having a higher temperature from the bottom of the crucible toward the upper part.SOLUTION: In the method for manufacturing a sapphire single crystal, a spacer 41 is arranged between the bottom of a crucible 14 and a seed crystal 15 and has 8.5 W/K or less of a heat conduction factor calculated by the following formulae (1) and (2). Thereby, a high quality sapphire single crystal without a crack can effectively prevents the occurrence of a crack in a growth crystal 21 caused by a temperature difference in the vertical direction in the growth crystal 21 and the degradation of crystallinity due to thermal strain. (the heat conduction factor)=(the thermal conductivity of a spacer material)×[(an average heat transfer area)/(the height of the spacer)] (1) and (the average heat transfer area)=[(an area of the spacer contacted with the crucible)+(an area of the spacer contacted with the seed crystal)]/2 (2).SELECTED DRAWING: Figure 4 |
