METHOD FOR THE PRODUCTION OF POLYCRYSTALLINE SILICON

摘要

The process for the production of polycrystalline silicon starting from metallurgical silicon, milled up to a predetermined granulometry, implies the reaction of metallurgical silicon with anhydrous hydrogen fluoride (HF), to obtain silicon tetrafluoride (SiF4), and to operate the synthesis of monosilane (SiH4) by a reaction of hydrogenation of the silicon tetrafluoride (SiF4) with alkaline or alkaline earth metals halide in fluid medium of organic solvent or melt salts. Then a thermal decomposition of said monosilane (SiH4) in a boiling-pseudo fluidized bed reactor is carried out, to obtain high purity granulated polycrystalline silicon.