Einkristall-Ziehvorrichtung mit verschiebbarem Schutzschild zur Kontrolle des Öffnungsbereiches um den Einkristall herum

摘要

A plurality of shield blades (21) for defining an opening (25) surrounding a single crystal (15) are provided between a melt (14) received in a crucible (10) and a screen (30). The shield blades (21) are carried by operation rods (23) so as to make the gap between the inner edges of the shield blades (23) and the surface of the single crystal (15) constant. Since crystal growth continues under the same condition from the beginning to the end, an obtained single crystal (15) is free from defects such as dislocations and excellent in homogenieity.