Molecular dynamics simulations of Si etching with energetic F⁺: Sensitivity of results to the interatomic potential

Comparative analyses of molecular dynamics (MD) simulation studies of reactive ion etching of Si are presented. A recently developed empirical potential is used to model the Si-F system, and applied to the simulation of Si etching with energetic F⁺ at 10, 25 and 50 eV. These results are compared to those of a similar study using the Stillinger-Weber Si-F potential. This analysis leads to the expected result that different potentials lead to quantitatively different results with regard to Si etch yield, surface structure and composition, etching mechanisms, and product distributions. More importantly, however, it attests to the robustness of the qualitative nature of these results. The degree of qualitative agreement between systems studied with the two potentials is high enough for us to conclude that MD simulations have revealed valuable qualitative insights into the complicated system of reactive ion etching of Si.