Feasibility of directional solidification of silicon ingot by electromagnetic casting

Electromagnetic casting is a novel technology that combines the advantages of electromagnetic cold crucible and continuous casting. By controlling induction heating and strengthening bottom cooling, multicrystalline silicon ingot with 60 mm×60 mm in cross section was continuously and directionally solidified by this technology. The ingot shows smooth surface and consists of uniform columnar crystals with no precipitate except in the top part. The grain size of the top part is smaller due to higher impurity content and the impurities acting as nucleation sites for grain. The density of dislocations at the bottom and middle parts, about 1×106 cm−2, is much less than that at the top part.