Etching of SiC by energetic F2: Molecular dynamics simulation

Abstract Molecular dynamics (MD) simulations were performed to investigate F 2 continuously bombarding silicon carbide (SiC) surfaces with energies in the range of 50–200 eV at normal incidence and room temperature. The Tersoff–Brenner form potential was used. The simulation results show that the uptake of F atoms, the etch yields of C and Si from the initial substrate, and the surface structure profile are sensitive to the incident energy. Like occurrence in Si etching, steady-state etching is observed and an F-containing reaction layer is formed through which Si and C atoms are removed. A carbon-rich surface layer after bombarding by F 2 is observed which is in good agreement with experiments. In the reaction layer, SiF in SiF 2 species are dominant; with increasing incident energy, the total fraction of SiF and SiF 2 increases, while the amount of SiF 3 and SiF 4 decreases. Finally, etching mechanisms are discussed.