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

Abstract

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.