| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a radiation shield of a single crystal pulling-up apparatus, which is improved in the pulling-up speed of a single crystal and can suppress the generation of crystal defects and the dislocation of the crystal. <P>SOLUTION: The radiation shield has a cylindrical straight barrel part 6b and a lower shoulder part 6c curving inward from the lower end of the straight barrel part and forming an opening on the lower end part. If the diameter of a single crystal to be grown is taken as Φ<SB POS="POST">cry</SB>(mm), the thickness size t<SB POS="POST">1</SB>of the lower end part opening of a heat-insulating member 6d of the lower shoulder part is prescribed by expression (1): t<SB POS="POST">1</SB>=0.1Φ<SB POS="POST">cry</SB>to 0.5 Φ<SB POS="POST">cry</SB>. When an inclined line at 45° against a horizontal surface described below is drawn toward the lower shoulder part from an intersection point of a virtual line extending downward the outer side surface of the heat-insulating member of the straight barrel part with the horizontal surface containing the lower end part of the heat-insulating member of the straight barrel part, the thickness size t<SB POS="POST">2</SB>of the heat-insulating member at the intersection point against the heat-insulating member is prescribed by expression (2): t<SB POS="POST">2</SB>≤2t<SB POS="POST">1</SB>. <P>COPYRIGHT: (C)2013,JPO&INPIT |
