For purpose of enhancement of mechanical properties, Al/Al2O3 films, with thickness A in the nanometric scale, were deposited on silicon substrate by reactive rf sputtering, at substrate temperatures Ts ranging from −90°C to 600°C. The characterisation (FEG-SEM, AFM, SIMS, XRR) has shown that Al/Al2O3 films are granular and rough, in correlation with the behavior of single alumnium films. The minimal roughness values are obtained at low Ts (−90°C and 25°C). The Λ = 20 rim-films are real multilayers, as confirmed by SIMS and XRR. Nevertheless, the multilayering character, i.e. the existence of multilayers, decreases when Ts increases. At low Ts, the relevant parameter to explain the weakness of stratification of Al/Al2O3 films is the roughness of layers, while at high Ts, the chemical interdiffusion clearly dominates, resulting in a no periodic structure at Ts = 600°C.

The tribological behaviour of Ti/TiN amorphous nanometric multilayers is reported in comparison with that of single Ti and TiN layers, in order to study the wear mechanism of nanostructures submitted to that one may call “macroscopic loading”. Ti/TiN nanolayers were deposited onto Si substrate by high vacuum diode r.f. sputtering assisted by in-situ kinetic ellipsometry. Transmission Electron Microscopy (T.E.M.) characterization exhibited the multilayered structure of the films, ascertained by grazing angle X-ray reflectometry and ellipsometry. Sliding wear tests against alumina in dry air showed the ceramic-typed behaviour of the multilayers, the wear of which was partly governed through a microfracture mechanism. Their wear lifetime was found to be higher than that of Ti and TiN single layers and increased with the number of layers.

In this paper, we report on the growth and the study of Ti/TiN nanometric multilayers. The preparation of these films has been carried out by high vacuum diode r.f. sputtering. Growth was in-situ monitored by kinetic ellipsometry. Deposition temperature was kept to room and low temperature (-120°C) respectively in order to modify the interface properties and consequently to understand the effect of the interfaces on the film's mechanical properties.

The thickness of each layer was varied from 1 nm to 10 nm and alternately repeated in order to obtain a total thickness of 200 nm. After deposition, films were characterized by means of X-ray diffraction and grazing X-ray reflectometry for structural determination. This study shows that the TiN-Ti boundary is composed of TiNx, with x going from the nominal nitrogen concentration of the TiN layer to 0. This can be due either to a surface reaction of the incident titanium during the Ti sequence with the nitrogen present at the film surface or to a reaction of nitrogen with the target surface during the TiN sequence.