Electron attachment to photofragments and Rydberg states in laser-irradiated CCl2F2

We report electron attachment measurements on ArF-excimer-laser irradiated CCl2F2, obtained using an improved experimental technique that allows simultaneous measurements on multiple electron attaching species. Compared to a maximum electron attachment rate constant of ∼2x10-9cm3s-1 for the ground electronic state of CCl2F2, we measure an order of magnitude larger rate constant for the CClF2 radical produced via laser photodissociation. However, the highly excited electronic states of CCl2F2 produced by the laser irradiation have an associated electron attachment rate constant that is at least four orders of magnitude larger compared to the ground electronic state value. Implications of these findings for plasma processing discharges using CCl2F2 are discussed. copyright 1998 American Institute of Physics