Measurements of F*, CF, and CF2 formation and decay in pulsed fluorocarbon discharges

Abstract

The temporal population profiles of F*, CF, and CF₂ in a sharp‐edged, pulsed (500 μs), fluorocarbon discharge are examined. F* population rises and falls with the discharge current suggesting that electron impact of the parent fluorocarbon is the primary source of emitting fluorine atoms. Ground‐state CF and CF₂, monitored by laser‐induced fluorescence, show noticeably slower formation and decay, but a simple kinetic model assuming that each arises from direct electron impact of the parent gas fits the data. It is shown that CF can be conveniently monitored by exciting the B̃(v’=2)−X̃(v‘=0) transition with a 193 nm ArF excimer laser.