Radical and molecular product concentration measurements in CF₄ and CH₄ radio frequency plasmas by infrared tunable diode laser absorption

Infrared tunable diode laser absorption studies of radicals and stable molecules formed in radio frequency (rf) plasmas are being carried out in a laboratory reactor which allows a long absorption path. In this paper we report studies of CF₄ and CH₄ rf plasmas. We report absolute concentration measurements as functions of total pressure and rf power for CF₂ and C₂F₆ in CF₄ plasmas and for CH₃ and C₂H₂ in CH₄ plasmas.