Abstract
Infrared diode laser absorption spectroscopy was used to measure the density of silyl ( SiH3) radicals in low-pressure (4.0 Pa) 13.56-MHz rf plasmas utilizing H2/, He/, Ar/, and Xe/SiH4 gas mixtures. The SiH3 production frequency per SiH4 molecule was also derived from the SiH3 density and its decay rate in the afterglow. The observed SiH3 density decreased with increasing dilution ratio in all the gas mixtures, but the SiH3 production frequency per SiH4 molecule increased significantly for Xe dilution and remained nearly constant for H2, He, and Ar dilution. Based on these results, the relative importance of different SiH3 production channels is discussed.