Effect of ion energy on degradation of diamond-like carbon films exposed to high-energy bombardment from an ion implanter

An as-deposited diamond-like carbon (DLC) film was post-treated with high-energy ion bombardment following the metal plasma ion implantation (MPII) process, involving an accelerated (10-80 kV or higher) vacuum-are metal plasma source with multiple charge states. In this study, carbon and titanium of varying ionic energy at a fixed dose of 2 X 10(17) ions cm(-2) were implanted in DLC films. The modification of the surface and consequent degradation of the DLC coatings, due to high-energy ion bombardment, were investigated. The as-deposited and ion-implanted films were characterized using Raman spectroscopy, Xray photoelectron spectroscopy (XPS), Auger electron spectroscopy, transmission electron microscopy (TEM) and a nano-indenter. The results indicate that the microhardness and sp(3)/sp(2) ratio declined from 16.2 to 11.6 GPa and 0.46 to 0.30, respectively, as the ion energy increased, since the highly energetic ion bombardment induced damage to the original lattice. (C) 2002 Elsevier Science B.V. All rights reserved.