Hydrogen gas production for electronic-grade polycrystalline silicon growth

The production of polycrystalline silicon (polysilicon) requires several main feedstocks. Polysilicon is produced by the reaction of trichlorosilane, SiHCl/sub 3/ (TCS) with hydrogen, H/sub 2/. Trichlorosilane is produced in the TCS plant while hydrogen is produced in H/sub 2/ plant. Hydrogen and oxygen can be produced from water using electricity through the process of electrolysis. The purification or rectification of the H/sub 2/ gas is typically done by passing an impure H/sub 2/ stream over a heated palladium (Pd) alloy. The purity of H/sub 2/ is then tested using a laboratory-constructed hydrogen gas purity test method which has been found to be at 99.9%.