Nanoindentation on carbon thin films obtained from a C60 ion beam

Raman spectra, atomic force microscope (AFM) images, hardness (H) and Young's modulus (E) measurements were carried out in order to characterize carbon thin films obtained from a C60 ion beam on silicon substrates at different deposition energies (from 100 up to 500 eV). The mechanical properties were studied via the nanoindentation technique. It has been observed by Raman spectroscopy and AFM that the microstructure presents significant changes for films deposited at energies close to 300 eV. However, these remarkable changes have not been noticeable on the mechanical properties: apparently H and E increase with higher deposition energy up to ∼11 and ∼116 GPa, respectively. These values are underestimated if the influence of the film roughness is not taken into account.