Correlation between spatial distribution of the components of reactive plasma flow and the stoichiometry and defectiveness of deposited coatings

Purpose: The subject of the presented research was reactive plasma generated by circular vacuum-arc sources used for deposition of thin hard coatings. Design/methodology/approach: Experimental investigations on spatial distribution of ionized and excited plasma components were performed with the use of the optical emission spectroscopy. Quantitative analysis of microdroplets distribution was carried out using measuring optical microscope supplied with the numerical image analysis system. Findings: Based on the obtained radial distributions of volatile and condensed components the general picture of plasma flow emitted by a single circular arc source was reconstructed. Radial distributions of analysed emitting elements and analysed fractions of microdroplets showed layered structures that depended on the discharge conditions. Research limitations/implications: The spectral method used for the reconstruction of concentration distributions of ionised and excited plasma components generated by a single circular arc source could not be used for reconstruction of such distributions in the vacuum chamber of the industrial device. Originality/value: The carried out investigations showed that the differences in spatial distributions of plasma active elements determine the uniformity of crystallization conditions in vacuum-arc deposition processes performed in large-scale multi-source industrial devices.