Parameters of Plasma and Kinetics of Active Particles in CF4 (CHF3) + Ar Mixtures of a Variable Initial Composition

Abstract

The electrophysical parameters of plasma and the kinetics of active particles in CF₄ + Ar and CHF₃ + Ar mixtures under induction RF (13.56 MHz) discharge are compared. It is shown that the CHF₃ + Ar system containing 0–75% Ar is intrinsic for systematically lower concentrations and flow densities of fluorine atoms, while they are higher in the case of fluorocarbon radicals and positive ions. The set of formal parameters in the form of flux density ratios is suggested in order to describe the formation and destruction of a fluorocarbon polymer film. It is confirmed that the advantage of the CHF₃ + Ar system according to the etching selectivity of SiO₂/Si is caused by its higher polymerization ability.