Laser deposition of diamond-like films from liquid aromatic hydrocarbons

Diamond-like films are deposited on transparent substrates upon exposure of its interface with liquid hydrocarbons (toluene C6H5CH3, benzene C6H6, and cumene C6H5CH(CH3)(2)) to pulsed visible laser radiation of a copper vapor laser (lambda = 510.6 nm). The X-ray Auger electron spectroscopy (XAES), Reflection High Energy Electron Diffraction (RHEED), profilometry, and ellipsometry are employed to characterize the deposited films. The sp(3) fraction in the films amounts to 60%-70% and depends on the precursor. The addition of diamond nanoparticles to the liquid precursor results in their incorporation into the film. The average film thickness on a glass substrate increases with the number of laser shots and then saturates at about 100 nm. The films show excellent adherence and have microhardness of 50-70 cpa, as measured by nanoindentor, The effect of auto-regulation of the film thickness is discussed as the result of competition between ablation and deposition of the film. (C) 2000 Elsevier Science B.V. All rights reserved.