Laser deposition of diamond-like films from liquid aromatic hydrocarbons

Abstract

Diamond-like films are deposited on transparent substrates upon exposure of its interface with liquid hydrocarbons (toluene C 6H 5CH 3, benzene C 6H 6, and cumene C 6H 5CH(CH 3) 2) to pulsed visible laser radiation of a copper vapor laser ( λ=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 GPa, 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.