Energy and mass spectroscopy studies during ion plating of hard coatings

Energy-resolved mass spectroscopy is a very versatile method for plasma characterisation. It enables the analysis of energy and mass distribution of ions and neutrals. Results show a good correlation between the average energy of the particles bombarding the surface and the properties of the layer (texture, stress free lattice parameter and in minor extend others such as microhardness and internal stress). Mass-spectroscopic studies, performed during TiN and TiC depositions reveal that the arc system with magnetic confinement is an efficient tool for ionisation of the evaporated Ti atoms via the electron impact ionisation, Tin++e−→Ti(n+1)++2e−, n=0–3, within the electron beam with an energy above 27.5 eV. At the same time the ionisation of the acetylene in Ar+C2H2 gas mixture is also very effective, leaving the hydrogen to be the most abundant neutral species beside argon. The dissociation via charge transfer and Penning ionisation/dissociation mechanism is almost complete. The most abundant hydro–carbon positive ion is C+, while the intensities of CHx+ and C2Hx+ ions are lower for an order of magnitude.