Synthesis and in-situ ellipsometric monitoring of Ti/C nanostructured multilayers using a high-current, dual source pulsed cathodic arc

Multilayered materials have been shown to enhance mechanical properties compared to single-phase materials. In this paper, we describe the deposition of Ti/C multilayered systems using a novel high current pulsed cathodic arc system with dual cathodes. We have chosen this system because titanium forms a ductile crystalline layer (which can be hardened by alloying with carbon) and carbon forms an amorphous layer (which can be tailored from soft sp 2 to hard sp 3 material). The mechanical properties of both layers can thus be varied over a wide range. The multilayer deposition was monitored with in-situ spectroscopic ellipsometry to accurately determine the thickness and optical constants of the individual layers. Important information regarding film nucleation and growth in the interfacial regions is deduced from the ellipsomteric data. The film thicknesses determined from the ellipsometric analysis are compared with cross-sectional transmission electron microscopy (TEM) images.