| 摘要 |
At least one molten zone is passed upwards through a silicon rod having a diameter of 30-40 mm from a thin seed using a water-cooled induction coil associated with a lower short-circuited conductor and at least one further molten zone is passed upwards through the rod from the seed using a water-cooled induction coil without a lower short-circuited conductor. The same or a separate coil may be used in the second passage; in the former case, a non-removeable conductor is de-short-circuited. According to Fig. 1 (not shown), a coil 4 has a conductor in the form of a removeable closed ring 5. According to Fig. 4 (not shown), a non-removeable conductor is in the form of a water-cooled coil 15 having engageable electric contacts 16a and 16b which are opened, by varying the pressure of the cooling liquid, to de-short-circuit the conductor. |
