Improvements in the production of mono-crystalline semiconductor material

摘要

The end of a rod 1 (Fig. 1) is maintained molten by means of a double turn induction coil 4 having an aperture of smaller cross-section than rod 1 and a narrow monocrystalline rod 3 is pulled from the melt through the aperture. Rod 1, which may be of germanium or silicon, is maintained stationary and induction coil 4 is lowered during pulling. Pulling may be effected in an inert atmosphere in a quartz vessel. The pulled rod may have a diameter of down to 1 mm. Double turn coil 4 may be replaced by a single turn coil 6 (Fig. 2) attached to a silver hood 5 having a vertical slit 7. Preheating may be effected by means of a molybdenum cap 8 and induction coil 10 (Fig. 3) which are removed before crystal-pulling or by a molybdenum ring 9 and induction coil 4 (Fig. 4) which are also used during crystal-pulling.