METHOD FOR PRODUCING POLYCRYSTALLINE SILICON

摘要

The subject matter of the invention is a method for producing polycrystalline silicon, comprising a) depositing of polycrystalline silicon by means of CVD on at least one U-shaped substrate which is heated by way of direct current passage to a temperature at which polycrystalline silicon is deposited on the substrate, as a result of which at least one U-shaped polycrystalline silicon rod pair is produced, wherein the substrate is connected at each of its free ends to a graphite electrode and is supplied with current in this way; b) removal of the at least one polycrystalline silicon rod pair from the reactor; c) elimination of graphite residues from the electrode-side ends of the at least two polycrystalline silicon rods of the at least one polycrystalline silicon rod pair; d) comminution of the at least two polycrystalline silicon rods into rod pieces or into fragments; characterized in that the graphite residues are chipped off each electrode-side end of the at least two polycrystalline silicon rods by means of at least one mechanical pulse.