湿式精錬によるW, Moの高純度化の研究

概要

論文の詳細を見る
Advanced semiconductor industries have recently required various high purity metals such as W, Mo, Si, Al, Ti and Ta. Especially manufacturers of more integrated semiconductors need purer materials with the very low harmful impurities, for example alkali (Na and K), radioactive (U and Th) and transition (Fe, Ni, Co and others) elements.The materials for gate electrode of MOS-LSI (Metal-Oxide-Semiconductor-Large-Scale-Integrated-circuits) are being shifted from poly-Si to high purity W-Si or Mo-Si and will be changed to ultrahigh purity W or Mo in the near future. Therefore it is vital to eliminate the impurities mentioned above from commercially available tungstic or molybdic compounds.In order to refine them the authors tested chemical processes i.e., is solvent extraction, ion exchange and crystallization. These chemical refinings have proven effective to remove alkali, alkaline-earth and transition elements. So, for the production of high purity metallic W and Mo, it is important to consider the features of the refining processes.
大同特殊鋼株式会社の論文