Surface Roughness of Various Diamond-Like Carbon Films

Atomic force microscopy is used to estimate and compare the surface morphologyof hydrogenated and hydrogen-free diamond-like carbon (DLC) films.The films were preparedby using DC magnetron sputtering of a graphite target,pulsed cathodic carbon arcs,electron cy-clotron resonance (ECR),plasma source ion implantation and dielectric barrier discharge (DBD).The difference in the surface structure is presented for each method of deposition.The influ-ences of various discharge parameters on the film surface properties are discussed based uponthe experimental results.The coalescence process via the diffusion of adsorbed carbon speciesis responsible for the formation of hydrogen-free DLC films with rough surfaces.The films withsurface roughness at an atomic level can be deposited by energetic ion impacts in a highly ionizedcarbon plasma.The dangling bonds created by atomic hydrogen lead to the uniform growth ofhydrocarbon species at the a-C:H film surfaces of the ECR or DBD plasmas.