A MOLECULAR-DYNAMICS STUDY OF ENERGETIC PARTICLE IMPACTS ON CARBON AND SILICON

Molecular dynamics simulations of energetic particle interactions with silicon and graphite crystal surfaces are discussed. The simulations can be used to describe the physical state of the surface after such interactions and the dynamic development of the resulting surface damage can be examined. We demonstrate in the case of atomic impact at energies greater than or approximate to a few hundred eV, that craters can form on silicon while bumps are formed on graphite. Impact of C-60 molecules is also discussed. On graphite, hexagonal surface waves propagate from the impact point and surface bonds remain unbroken at energies approximate to a few hundred eV. The interactions with silicon surfaces at impact energies of approximate to few eV depend crucially on the form of the potential. At keV energies the C-60 molecule disintegrates and a large crater forms near the impact point.