Laser-Induced-Fluorescence Study of SiH₂ in a RF SiH₄/SiH₂C1₂ Plasma

Abstract

The behavior of the SiH₂ radical in a RF (13.56 MHz) SiH₄/SiH₂Cl₂ mixture plasma wasinvestigated usinglaser-induced fluorescence spectroscopy with pulsed as well as CW laser excitation. Itwas shown that SiH₂ inthe mixture plasma is mainly produced via dissociation of SiH₄ and it is less reactivewith SiH₂Cl₂ than with SiH₄. The SiH₂ density in the mixture plasma increased slightly with increasing SiH₂Cl₂ fraction, despite thedecrease in the SiH₄ density. This enhanced decomposition of SiH₄ as a result of SiH₂Cl₂ admixing was foundto be caused by the increase in the electron temperature, which resulted from the increase in the density ofelectron-attaching species produced from SiH₂Cl₂ in the plasma.