Hard DLC film formation by gas cluster ion beam assisted deposition

Abstract

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.