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

Abstract

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-arc metal plasma source with multiple charge states. In this study, carbon and titanium of varying ionic energy at a fixed dose of 2×10 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, X-ray 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.