Hard DLC film formation by gas cluster ion beam assisted deposition

Diamond-like carbon (DLC) films with high hardness were formed by Ar cluster ion beam assisted deposition at room temperature, using C-60 as a carbon source. The gas cluster ion beam (GCIB) assisted deposition was useful to form hard DLC films, as the bombardments induced high-pressure and high-temperature effects at the impact surface, and ultra low energy effects. When the acceleration energy of Ar cluster ion was 5 keV, the hardness of 50 GPa was obtained. This value was approximately two times higher than that of the films deposited with conventional methods. Wear-resistance properties were also higher than that of conventional films. Rough estimations of sp(2) orbital in the films were carried out with Raman spectra, the films formed with Ar cluster ion bombardment had lower sp(2) contents, which meant films had low fraction of graphite bonding. Thus DLC films exhibiting higher physical characteristics and lower graphite bonding were obtained with GCIB assisted deposition. (C) 2002 Elsevier Science B.V. All rights reserved.