US Patent 7632329 Method of refining scrap silicon using an electron beam

A method of refining scrap silicon using an electron beam includes a step of selectively preparing lumps of n-type scrap silicon containing a specific impurity element as a dopant, a step of crushing the prepared lumps of scrap silicon, a step of placing the crushed silicon into a vacuum vessel, a step of irradiating the crushed silicon which was placed into the vacuum vessel with an electron beam to melt it and vaporize at least a portion of the impurity element, and a step of solidifying the resulting silicon.