Transport coefficients for electron scattering in CF4/Ar/O2 mixtures with a significant presence of Fx or CFx radicals
Institute of Physics, University of Belgrade - Pregrevica 118, 11080 Belgrade, Serbia
2 Jozef Stefan Institute - Jamova cesta 39, 1000 Ljubljana, Slovenia, EU
Accepted: 16 August 2010
We present transport coefficients for electrons in mixtures of CF4 with Ar and O2 which are used in plasma etching, for ratios of the electric field to the gas number density E/N from 1 Td to 1000 Td (1Td=10−21 Vm2). We then add a certain percentage of radicals produced by dissociation of CF4. Our analysis of non-conservative collisions revealed a range of E/N where electron attachment introduced by radicals significantly changes the electron kinetics obtained for mixtures without dissociation of the CF4 gas. Results are obtained by using a simple, two-term solution for Boltzmann's equation and by Monte Carlo simulations.
PACS: 51.10.+y – Kinetic and transport theory of gases / 51.50.+v – Electrical properties (ionization, breakdown, electron and ion mobility, etc.) / 52.25.Fi – Transport properties
© EPLA, 2010