A facile method for the deposition of thermally stable diamond like carbon thin films via carbon dioxide precursor gas

Abstract

The thermal stability and tribological performance of silicon- and oxygen-incorporated diamond-like carbon (DLC) and silicon doped-DLC films were investigated. The DLC and DLC:Si are deposited on various (silicon, stainless steel and aluminium) substrates within the thickness range 200–400nm by radio frequency plasma-enhanced chemical vapour deposition (PECVD) method. Carbon dioxide (CO2) precursor gas is used to reduce the hydrogen content and to increase the adhesion of the films to the substrate. The X-ray photoelectron spectroscopy, Raman spectroscopy, surface profilometry and nano-indentation are used to study the chemical composition, microstructure, thermal stability and mechanical properties of the films. For CO2 precursor made DLC samples, Raman parameters did not show any significant change up to temperature 500°C. The lowest coefficient of friction was found to be 0.298 for the DLC:Si film prepared with CO2 at room temperature and corresponded lowest wear rate of 1.77×10−10mm3/Nm. The micro-structural properties at various annealing temperature were critically analysed by monitoring graphitization behaviour and oxidation of the film surface.