To make the grain size large by a simple apparatus by gradually cooling a molten Si to precipitate a crystal from below with applying a measure field to the Si.
A crucible 3 for melting Si must be made of a material durable enough to the temp. of the molten Si, without reacting with Si, has pref. a conical bottom shape. A crystal first precipitates at the bottom of the crucible 3 and those in the initial stage mostly have small grain sizes. Hence a crucible having a larger bottom area provides a high productivity of Si of smaller grain sizes. By making conical, the productivity of small-grain size Si can be reduced. The type of heater 4 for heating is not limited but usually a carbon heater is energized by a d-c current to heat. Orientation of the applied magnetic field is not limited and may be horizontal or vertical.
ASABA MASASHI
MAEJIMA YOSHIBUMI
KAWASAKI KOICHI
JAPAN SCIENCE & TECH CORP