Molecular-dynamics simulations of energetic C{sub 60} impacts on (2x1)-(100) silicon
- Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)
Single impacts of energetic C{sub 60} clusters on (2x1)-(100) silicon substrates are studied by molecular-dynamics simulations. The role of impact energies and internal cluster energy are investigated in detail. Six different energy regimes can be identified at the end of the ballistic phase: At thermal energies below 20 eV the fullerene cages undergo elastic deformation, while impinging on the surface, and are mostly chemisorpted on top of the (2x1)-dimer rows. Between 20 and 100 eV the cage structure is preserved after the collision, but the cluster comes to rest within a few monolayers of the silicon surface. At energies of 100-500 eV the cluster partially decomposes and small coherent carbon caps are embedded in the surface. At higher energies up to 1.5 keV complete decomposition of the fullerene cluster occurs and an amorphous zone is formed in the subsurface area. At energies greater than approximately 1.5 keV craters form and above 6 keV sputtering becomes significant. In all cases the substrate temperature is of minor influence on the final result, but the projectile temperature is important for impacts at lower energies (<1.5 keV). For high energy impacts the ballistics resemble that of single atom impacts. Nearly 1:1 stoichiometry is obtained for impact energies around 1 keV. These results reveal an interesting possibility for controlled implantation of C in Si at high local concentrations, which might allow the formation of silicon carbide. (c) 2000 American Institute of Physics.
- OSTI ID:
- 20216833
- Journal Information:
- Journal of Applied Physics, Vol. 88, Issue 1; Other Information: PBD: 1 Jul 2000; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
Similar Records
Surface scattering of C[sub 60][sup +]: Recoil velocities and yield of C[sub 60]
Ab initio study of adsorption and decomposition of NH{sub 3} on Si(100)-(2x1)