SPACE-RESOLVED AND TIME-RESOLVED MEASUREMENTS OF CF AND CF2 RADICALS IN HIGH-DENSITY CF4 PLASMAS BY LASER-INDUCED FLUORESCENCE

Ground-state CF and CF2 radicals in CF4 helicon plasmas of high density were detected by laser-induced fluorescence (LIF). The LIF was used to measure the spatial and temporal variations of CF, concentrations. The CF2 concentration increases near 5-10 ms after the extinction of rf power, and the degree of this increase depends upon the discharge condition; plasma duration, plasma density, and CF4 pressure. The result indicates that this behavior in the afterglow is closely related to the interactions of the rf-on phase between radicals and a quartz surface with deposited fluorocarbon polymers. (C) 1995 American Institute of Physics.