Practical Method for Producing a Large Amount of Isotopically Enriched Silicon by Infrared Multi-Photon Dissociation of Hexafluorodisilane

Abstract

This paper presents a practical method for producing highly enriched silicon isotopes utilizing laser irradiation. One-or twofrequency CO 2 laser irradiation has been employed to separate the desired isotope of silicon by means of infrared multiphoton dissociation (IRMPD) of hexafluorodisilane (Si 2 F 6 ) molecules using a flow reaction system. The production of Si 2 F 6 with a 28 Si fraction of 99.1% at a rate of 0.67 g ( 28 Si)/h was successfully accomplished with a yield of about 63% by twofrequency laser irradiation. Enriched SiF 4 gas with 30 Si exceeding 31% was also continuously obtained at a production rate of 0.12 g/h by one-frequency laser irradiation.