Electronic Structures of CF 3 - for Studying Dissociative Electron Attachment to CF 3 Radicals

• Published in: Japanese Journal of Applied Physics 2004-05, Vol.43 (5R), p.2711
• Main Author: Hayashi, Daiyu
• Format: Article
• Language: English
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.43.2711

To elucidate the process of dissociative electron attachment (DA) to CF 3 radicals, the potential energy surfaces of CF 3 , CF 3 - and the electronic state CF 3 -* temporally produced in DA are calculated at the MP2/6-311++G** level by Gaussian 98. The electron affinities ( E A ) of the CF 3 , vibrational frequencies of CF 3 and CF 3 - are also calculated. Our results are in good agreement with the experimental values (cf. E A =1.72 eV, experimental value = 1.7±0.2 eV). It is elucidated that the electron capture by CF 3 under the adiabatic approximation occurs by the incident of a low-kinetic energy (∼0.6 eV) electron. DA to CF 3 is a slightly endothermic process with 0.2–0.4 eV. It is concluded that CF 3 radicals produce F - ions via DA with low kinetic energies. This process is considered to be very important in the kinetics of low-energy electrons in fluorocarbon plasmas.