Nonequilibrium radio frequency plasma interacting with a surface

In this paper, we discuss the successive results of our series of investigations into a two-frequency capacitively coupled plasma in CF ₄(5%)/Ar, sustained by a very high frequency source and biased by a low frequency source in a collision-dominated region. The nonequilibrium in a collisional radiofrequency plasma is studied in terms of the velocity distribution of charged particles. In the bulk plasma, especially, we discuss the velocity distribution of electrons influenced by the quantum structure of a feed gas molecule, and in the passive ion sheath, we predict the flux velocity distribution of positive ions. We then investigate the active species interacting with a patterned SiO₂ wafer surface and predict each species' contribution to the feature profile, and discuss the relationship between the pattern size and the etch rate.