Abstract
The growth conditions for large bulk silicon crystals were examined using the modified infrared convergent-heating floating zone method. The positions of the mirror-lamp (M-L) systems were systematically shifted from positions close to the molten zone to those more distant than the conventional position. The shape of the grown crystals was found to be affected by the position of the M-L system. When the system was close to the molten zone, crystals with a spiral shape were grown when larger tetragonal feed rods were used. At more distant positions, however, the growth of spiral-shaped crystals was suppressed. Crystals with cylindrical shape were grown.
