Substrate rotation-induced chemical modulation in Ti-Al-O-N coatings synthesized by cathodic arc in an industrial deposition plant
2016 (English)In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 305, 249-253 p.Article in journal (Refereed) Published
Reactive cathodic arc evaporation of Ti-Al-O-N was carried out in an industrial deposition system with two-fold substrate rotation. The structural and compositional evolution of the coatings was studied by combining scanning transmission electron microscopy and 3D atom probe tomography (APT). The formation of alternating O- and N-rich sublayers was identified by APT and can be understood by considering the substrate rotation induced variation in plasma density and fluxes of film-forming species. The effect of plasma density and fluxes on the incorporation of reactive species was studied in stationary deposition experiments and preferred N incorporation occurs, when the growing coating surface is facing the arc source. Thus, the growing surface is positioned in a region of high plasma density characterized by large fluxes of film forming-species. Preferred O incorporation takes place in a region of low plasma density where small fluxes are present, when the growing surface is blocked from the arc source by the substrate holder. Hence, compositional modulations are caused by substrate rotation as the growing coating surface is periodically exposed to regions of high plasma density and large fluxes of film-forming species and regions of low plasma density and small fluxes. These findings are highly relevant for all reactive industrial plasma assisted physical vapor deposition processes utilizing substrate rotation.
Place, publisher, year, edition, pages
2016. Vol. 305, 249-253 p.
Physical vapor deposition, Transition metal aluminium oxynitrides, Chemical composition modulation, Atom probe tomography
Atom and Molecular Physics and Optics
IdentifiersURN: urn:nbn:se:uu:diva-307259DOI: 10.1016/j.surfcoat.2016.08.046ISI: 000384855100032OAI: oai:DiVA.org:uu-307259DiVA: diva2:1046463
FunderGerman Research Foundation (DFG), SFB-TR 87/2