Electron kinetics in radio-frequency plasmas: excimer Ne-Xe-HCI mixture

Electron energy distribution functions (EEDF) in Ne-Xe-HCI mixture have been calculated by solving the time dependent Boltzmann equation in the presence of a sinusoidal field E(t)/p0=(E0/p0) cos(omega t). The results have been obtained for different reduced field frequencies omega ( pi *104<or= omega <or= pi *107 s-1 Torr-1), while the field amplitude E0/p0 has been self-consistently calculated by imposing an electron balance during the period between the gain by ionisation processes and the losses by dissociative attachment and ambipolar diffusion. Different fixed concentrations of excited states have also been considered to understand the role of superelastic collisions as well as ionisation and attachment from excited states in affecting EEDF. The results at the fixed omega /p0 show that the presence of excited states strongly decreases the modulation of EEDF enlarging its tail at the same time. Moreover the ionisation frequency from excited Xe* is such as to decrease the self-consistent field amplitude necessary to sustain the electrical discharge. Finally the results for different field frequencies show that a complete quasi-stationary situation is only reached at Gw approximately pi *104 s-1 Torr-1.