Silane purification via laser-induced chemistry

Abstract

PH3, AsH3, and B2H6 have been removed from SiH4 by means of selective photolysis with an ArF uv laser. The absolute absorption cross sections for SiH4, PH3, AsH3, and B2H6 have been determined over the region 190–200 nm. Quantum yields for destruction of the contaminant species have been measured at 193 nm. The effects of free-radical reactions subsequent to photolysis on the selectivity of removal of PH3, AsH3, and B2H6 were found to be minimal. These results suggest that the purification of SiH4 via a laser-induced chemical process may be of considerable practical importance.