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The current investigations are focussed on high-speed passenger-traffic and commercial-freight transportation railway wheel and tyre steels, which were provided by a system supplier of the DB AG in technically relevant heat treatment conditions. As a consequence of the industrial heat treatment, microstructural gradients emerge in the rim of monobloc wheels and tyres, leading to a local-dependence of the fatigue behaviour. Fatigue specimens, representing the local microstructure were machined from defined depth-positions. The fatigue behaviour at ambient temperature and elevated service temperatures was assessed by mechanical stress-strain hysteresis and electrical resistance measurements. The local microstructure influences the fatigue behaviour in a characteristic manner.

We present the results of a systematic benchmarking study, using 45nm-groundrule structures, of a commercially-available ionized PVD Cu technology which employs an in-situ Ar+ radio-frequency (Rf) plasma capability for enhanced coverage, and compare its performance and extendibility against the same seedlayer process operated in conventional low-pressure mode. Studies of single-damascene lines and dual-damascene via structures indicate that the PVD Cu seedlayer with Rf-Plasma enhancement enables a reduction of the PVD Cu seed thickness on the order of 35%, based on studies of Cu voiding, via-yield degradation, and transmission-electron microscopy (TEM). These results illustrate the critical importance of the Rf-plasma resputter capability in extending the PVD Cu process to advanced groundrules at 45nm and beyond.

A reactive ac pulsed dual magnetron sputtering process for MgO thin-film deposition was equipped with a closed-loop control of the oxygen flow rate (FO2) using the 285nm magnesium radiation as input. Owing to this control, most of the unstable part of the partial pressure versus flowrate curve became accessible. The process worked steadily and reproducible without arcing. A dynamic deposition rate of up to 35nmm∕min could be achieved, which was higher than in the oxide mode by about a factor of 18. Both process characteristics and film properties were investigated in this work in dependence on the oxygen flow, i.e., in dependence on the particular point within the transition region where the process is operated. The films had very low extinction coefficients (<5×10−5) and refractive indices close to the bulk value. They were nearly stoichiometric with a slight oxygen surplus (Mg∕O=48∕52) which was independent of the oxygen flow. X-ray diffraction revealed a prevailing (111) orientation. Provided that appropriate rf plasma etching was performed prior to deposition, no other than the (111) peak could be detected. The intensity of this peak increased with increasing FO2, indicating an even more pronounced (111) texture. The ion-induced secondary electron emission coefficient (iSEEC) was distinctly correlated with the markedness of the (111) preferential orientation. Both refractive index and (111) preferred orientation (which determines the iSEEC) were found to be improved in comparison with the MgO growth in the fully oxide mode. Consequently, working in the transition mode is superior to the oxide mode not only with respect to the growth rate, but also to most important film properties.