ELECTRON-ATTACHMENT TO PHOTOFRAGMENTS AND RYDBERG STATES IN LASER-IRRADIATED CCL2F2

We report electron attachment measurements on ArF-excimer-laser irradi ated CCl2F2, obtained using an improved experimental technique that al lows simultaneous measurements on multiple electron attaching species. Compared to a maximum electron attachment rate constant of similar to 2 x 10(-9) cm(3) s(-1) for the ground electronic state of CCl2F2, we measure an order of magnitude larger rate constant for the CClF2 radic al produced via laser photodissociation. However, the highly excited e lectronic states of CCl2F2 produced by the laser irradiation have an a ssociated electron attachment rate constant that is at least four orde rs of magnitude larger compared to the ground electronic state value. Implications of these findings for plasma processing discharges using CCl2F2 are discussed. (C) 1998 American Institute of Physics. [S0021-8 979(98)08519-3].