| 摘要 |
<p>A high frequency(h.f.) induction coil (3) is located in a vessel (1) which is evacuated or filled with inert gas; and a vertical silicon rod (5) is drawn downwards through coil (3) for zone melting without a crucible. In the wall of vessel (1) is a gastight passage for an h.f. conductor (2), which is connected to coil (3) via a bent or curved lead (14). Lead (14) is pref. bent downwards towards the recrystallised part (4) of rod (5); and part (4) is pref. surrounded by a protective cylindrical sleeve (7), 15-100 cm dia., and coated at least in its bore with Al or Ag. The axial distance between the top edge of sleeve (7) and coil (3) is pref. 0-10 cm. Used to eliminate thermal stresses in part (4), which could lead to cracks in the latter when the rod is cooled, esp. with Si rods e.g. 10 cm in dia.</p> |
