Influence of base pressure prior to deposition on the adhesion behaviour of carbon thin films on steel

•Influence of deposition base pressure on carbon-based thin film adhesion.•Adhesion is enhanced in lower deposition base pressures.•The base pressure controls the failure type in terms of adhesion interface.•Oxygen content is associated with poor adhesion behaviour. The poor adhesion of carbon thin films was the main restriction for its massive application in recent years. Physicochemical interaction improvement at the adhesion interface between substrate and thin film is one of the most important fields of research to overcome such problem. From a chemical point of view, oxygen seems to be a major issue in the adhesion control. In this work, the influence of base pressure prior to deposition process on the carbon thin film tribological behaviour was studied. Rockwell C and scratch tests were performed to qualify the thin film failures and adhesion. Chemical mapping was performed by energy-dispersive spectroscopy to characterise the chemical elements after thin film failure. The carbon thin films show better adhesion at lower base deposition pressures. The tribological behaviour is associated with the oxygen content in the chamber atmosphere as well as to the higher thin film adhesion achieved at lower base pressures. [Display omitted]