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Molecular-dynamics simulations of energetic {C}-60 impacts on (2x1)-(100) silicon

Hu, X. Y. and Albe, K. and Averback, R. S. (2000):
Molecular-dynamics simulations of energetic {C}-60 impacts on (2x1)-(100) silicon.
In: J. Appl. Phys., American Institute of Physics, pp. 49-54, 88, (1), [Online-Edition: http://jap.aip.org/resource/1/japiau/v88/i1/p49_s1],
[Article]

Abstract

Single impacts of energetic C60 clusters on (2×1)-(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 (2×1)-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.

Item Type: Article
Erschienen: 2000
Creators: Hu, X. Y. and Albe, K. and Averback, R. S.
Title: Molecular-dynamics simulations of energetic {C}-60 impacts on (2x1)-(100) silicon
Language: English
Abstract:

Single impacts of energetic C60 clusters on (2×1)-(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 (2×1)-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.

Journal or Publication Title: J. Appl. Phys.
Volume: 88
Number: 1
Publisher: American Institute of Physics
Uncontrolled Keywords: digital simulation, elemental semiconductors, atomic clusters, molecule-surface impact, sputtering, chemisorption, SILICON, FULLERENES, COLLISIONS, SIMULATION, MOLECULAR DYNAMICS METHOD, MOLECULAR CLUSTERS, SURFACES, ENERGY DEPENDENCE, KEV RANGE, EV RANGE, DEFORMATION
Divisions: 11 Department of Materials and Earth Sciences
11 Department of Materials and Earth Sciences > Material Science
11 Department of Materials and Earth Sciences > Material Science > Materials Modelling
Date Deposited: 28 Feb 2012 15:18
Official URL: http://jap.aip.org/resource/1/japiau/v88/i1/p49_s1
Identification Number: doi:10.1063/1.373622
Related URLs:
Funders: This work was funded in part by the National Science Foundation under Grant No. DM9632232 and the US Department of Energy, Basic Energy Sciences under Grant No. DEFG02-91ER45439., One of us ~K. A.! was also supported by the US Department of Energy through the University of California under Subcontract No. B341494.
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