Structural properties and growth evolution of diamond-like carbon films with different incident energies: A molecular dynamics study

Structural properties and growth evolution of diamond-like carbon (DLC) films with different incident energies were investigated systematically by the molecular dynamics simulation using a Tersoff inter-atomic potential for carbon-carbon interaction. The results revealed that the density, sp(3) fraction and residual compressive stress as a function of incident energy increased firstly and then decreased; when the incident energy was 70 eV/atom, the density could reach to 3.0 g/cm(3) with the maximal compressive stress of 15.5 GPa. Structure analysis indicated that the deviation of both bond angles and lengths from the equilibrium position led to the generation of a large residual stress, while the high compressive stress mainly attributed to the decrease of both bond angles and lengths among carbon atoms. The growth of DLC films underwent a formation process of "Line-Net" structure accompanied with the interaction of many atomic motion mechanisms, and the "Point" stage was only found for DLC films with low incident energy. (C) 2013 Elsevier B.V. All rights reserved.