Measurement and Calculation of SiH2 Radical Density in SiH4 and Si2H6 Plasma for the Deposition of Hydrogenated Amorphous Silicon Thin Films

SiH 2 radical density in SiH 4 and Si 2 H 6 plasmas diluted with He, Ar and Xe has been measured using intracavity laser absorption spectroscopy, and analyzed by a gas-phase reaction simulation. The density of SiH 2 increases with dilution due to increase in dissociation rate of parent-gas molecules. The increase in the dissociation rate for He and Xe dilution originates in the increase of electron energy and density, respectively, and both of these contribute for Ar dilution.