Device for obtaining a multicrystalline semiconductor material, in particular silicon, and method for controlling the temperature therein

A device (1) for obtaining multicrystalline silicon, including: at least one crucible (3) made of quartz for the silicon, removably housed in a cup-shaped graphite container (4); a fluid- tight openable casing (5); a top induction coil (12), set facing, with interposition of a graphite plate (14), the crucible, a lateral induction coil (16), set around a side wall (17) of the graphite container, and a bottom induction coil (18), set facing a bottom wall (19) of the graphite container and vertically mobile for varying the distance (D) from the bottom wall; and first means (20) for a.c. electrical supply of the induction coils separately from one another, and second means (21) for supply of a coolant within respective hollow turns of the induction coils; the bottom induction coil includes four spiral windings (31-34), arranged alongside one another according to a chequered scheme in one and the same plane of lie, which is defined by an insulated supporting plate (35); electrical switching means (40) enable in u