Title

Molecular Dynamics Simulation of the Growth of Thin Films by Deposition of Carbon Atoms and C60 Molecules on Diamond and Silicon Substrates

Document Type

Article

Publication Date

3-29-2005

Department

Physics and Astronomy

Abstract

The impact of C atoms and C60 molecules with ideal diamond and silicon (100) substrates and the subsequent growth of carbon films have been investigated by molecular dynamics simulations. The interatomic many-body potential proposed by Tersoff has been used. The structural and vibrational properties of the as-grown and annealed films are studied as a function of the deposition energy (in the range 1–150eV for C atoms and 1–1000eV for C60 molecules) and are compared with experimental results. Analysis of films grown from C60 molecules reveals a behavior with deposition energy similar to that experimentally observed. For low deposition energies (below 100eV) fullerene cages preserve their identity, constructing low-density structures with large intermolecular holes and practically no interface with the substrate. For higher deposition energies the molecules are broken into pieces, giving as a result high-density amorphous carbon films. Although the penetration depth of molecular fragments into the substrate increases with deposition energy, the resulting interface is considerably thinner than in the case of using individual atoms as projectiles. This is in agreement with experimental evidence of a poor adherence of films obtained by accelerating C60+ ions on silicon substrates.

Publication Title

Physical Review B

DOI

10.1103/PhysRevB.71.115431