ELECTROMAGNETIC CASTING METHOD OF SILICON INGOT

PROBLEM TO BE SOLVED: To provide a method for manufacturing a silicon ingot which is suitable as a raw material of a substrate material of a solar cell by inhibiting contamination due to copper of the silicon ingot caused by a copper cooling mold.SOLUTION: The present invention relates to an electromagnetic casting method of the silicon ingot in which a polycrystalline silicon ingot is continuously cast by charging the silicon raw material into the copper bottomless cooling mold 1, melting it by electromagnetic induction, pulling down the melt silicon, and solidifying it, wherein a mold length (L) positioned below from a lower end of an induction coil 2 surrounding the copper mold is set to more than 40 mm and no more than 180 mm so as to inhibit diffusion or mixing of copper to an internal part from an outer peripheral part of the silicon ingot close to the copper mold. It is desirable that the embodiment is adopted, wherein the polycrystalline silicon ingot with a square or rectangular cross section having a length of one side of 322 mm or more and 530 mm or less is an object to be cast.