Special Aspects of the Kinetics of Reactive Ion Etching of SiO2 in Fluorine-, Chlorine-, and Bromine-Containing Plasma

Abstract

The influence of the type of active gas and the ratio of the concentration of the components of the CF4 + Ar, Cl2 + Ar, and HBr + Ar mixtures on the parameters of the plasma, steady-state concentrations of the active particles, and kinetics of reactive-ion etching of SiO2 is investigated. It is demonstrated that the rate of etching SiO2 decreases in the CF4–Cl2–HBr series and is characterized by nonmonotonic (with the maximum at 20–25% Ar) behaviour under the variation of the initial composition of the mixtures. It is found that the reasons for the nonmonotonicity for each of the mixtures are the increased effective probability of the interaction and decreased yield of etching due to the change in the physical parameters of the plasma and densities of the fluxes of the active particles.