Isotope-Selective Infrared Multiple Photon Decomposition of Hexafluorodisilane

Article abstract of DOI:10.1021/j100280a052

The infrared multiple photon decomposition of hexafluorodisilane has been studied with a CO2 TEA laser with the intention of silicon isotope separation.The products were SiF4 (55 percent in silicon balance), a trace of Si3F8, and a whitish film.SiF4 was found to be considerably enriched with 30Si in the decomposition at P(6)-P(20) lines of the 10.6-μm CO2 band.Product yields and enrichment factors were examined as funcitons of irradiation wavenumber, laser fluence, and Si2F6 pressure.Decomposition occorred at a fluence as low as 0.15 J cm-2.The isotope content of 30Si in SiF4 was nearly 50 percent for example, in the irradiation of 2 Torr of natural Si2F6 with laser radiation at 951.19 cm-1 and 0.25 J cm-2.On the basis of the observed results, large-scale separation of 30Si was carried out by using a flow system and a high-repetition laser.SiF4 with a 30Si content of 33 percent was produced at a rate of 1.47 g/h.