Atomic force microscopy studies of films deposited from ${\mathrm{C}}^{+}$ ions are reported. For ${\mathit{C}}^{+}$ energies E≥30 eV the films are diamondlike and retain the initial smoothness of the silicon substrate. For E<30 eV graphitic films evolve with the surface roughness increasing with decreasing ${\mathrm{C}}^{+}$ energy. It was further found that for 120 eV ${\mathrm{C}}^{+}$ deposition, at substrate temperatures ${\mathit{T}}_{\mathit{s}}$<150 °C diamondlike, smooth films are deposited, while for ${\mathit{T}}_{\mathit{s}}$>150 °C graphitic, rough films are produced. The results substantiate the subplantation model, manifesting the role of subsurface internal growth in diamondlike film formation.

• Received 3 December 1993

DOI:https://doi.org/10.1103/PhysRevLett.72.2753