| 摘要 |
PURPOSE:To carry out the effective cooling of a single crystal, and facilitate the production of a large-sized single crystal by the CZ process, by using a single crystal-pulling shaft consisting of an inner main shaft for pulling and the outer heat-insulation layer. CONSTITUTION:The forcibly coooled shaft (main shaft for pulling) 11 has a double-tube structure consisting of the core tube 12 and the outer tube 13. The coolant 14 is introduced into the core tube 12 and discharged from the outer tube 13 to cool the single crystal. The outermost tube 15 is placed concentrically to the outside of the cooled shaft 11, a heat-insulation material 16 is filled between the outermost tube 15 and the cooled shaft 11, and a radiation shield 17 is attached to the outer surface of the outermost tube 15. A seed crystal 3 is attached to the holder 6 at the lower end of the cooled shaft 11, and the pulling of a single crystal is carried out. Since the cooled shaft 11 is shielded from the heat of the outer atmosphere 18, the single crystal can be cooled effectively via the seed crystal 3 and the holder 6, and a large-sized single crystal can be produced. |
