Molecular dynamics modeling of chemical erosion of hydrocarbon films

The erosion of hydrocarbon layers at room temperature due to co-bombardment of energetic (150 eV) argon ions and thermal atomic hydrogen is investigated. Using molecular dynamics simulations a mechanism has been identified explaining the experimentally observed increase of the physical sputtering yield. The surface erosion process is primarily a physical sputtering mechanism, enhanced by the screening effect of hydrogen atoms. This causes emission of unsaturated hydrocarbon molecules from the surface within a few picoseconds after ion impact and a superthermal energy distribution of the emitted molecules.