On the structure of argon assisted amorphous carbon films

We report a study of amorphous carbon films prepared by ion beam assisted d eposition (IBAD). X-ray and ultraviolet photoelectron spectroscopy were use d for probing the photoelectron core level and valence band of the films, r espectively. Raman spectra, stress, and film density were also determined. The intrinsic compressive stress and plasmon energy increase sharply for ar gon assisting energies up to 100 eV, and vary slightly for energy in the 10 0 eV to 650 eV range. The highest stress (> 10 GPa) and plasmon energy (29. 5 eV), achieved at about 400 eV argon assisting energy, are of the same ord er as those reported for highly tetrahedral amorphous carbon films. However , structural investigations indicate that the material is composed of a hig hly compressed and dense sp(2) network. (C) 2000 Elsevier Science S.A. All rights reserved.