Creation of the reactive species within the plasma phase by electron-neutral collisions and subsequent chemical reactions: e- + CF4 → CF3 + F + e-
Transport of the reactive species from the plasma to the substrate.
Adsorption of the reactive species on the surface (either physisorption or chemisorption, Fig. 3).
Dissociation of the reactant, formation of chemical bonds to the surface, and/or diffusion into the substrate with subsequent formation of the desorbing species: F* + SiFx → SiFx+1
Desorption of the product species: SiF4(s) → SiF4(g)
Transport of the product species into the plasma.
Simultaneous re-deposition of etching products.