Gaseous products from the reaction of XeF2 with silicon

Abstract

XeF₂ was reacted with silicon, and the gaseous products were detected using modulation techniques which made the experiments sensitive only to products which had not collided with a wall. In agreement with previous experiments, SiF₄ was found to be the major reaction product. Radicals such as SiF and SiF₂ were observed at a much lower level. However, SiF₂ was not found to be the dominant species as might have been suspected on the basis of experiments by other workers with atomic fluorine. Bombardment with 2000‐eV argon ions enhanced the rate of product formation and decreased the fraction of the products that was SiF₄. Production of radical species, in particular SiF₂, was enhanced. Collisions of SiF₂ with fluorinated, stainless‐steel vacuum chamber walls were investigated in order to determine whether the SiF₂ radical was converted to SiF₄ as suggested by others. Wall reactions were found to be important in some circumstances and not important in others.