Nanocomposite films of ZrN-Me ͑Me= Ag, Au, or Pd͒ were produced by reactive unbalanced magnetron sputtering and were found to form a dense and homogeneous microstructure whereby nanocrystals of Me are distributed evenly throughout the ZrN matrix. Interestingly, the Young's modulus was found to decrease much more dramatically with the increase in metal content for the ZrN-Ag system. A systematic ab initio study was undertaken to understand the mechanism of grain boundary sliding in these nanostructures. The maximum energy variation during the sliding was found to be the largest and the smallest for ZrN-Pd and ZrN-Ag, respectively.

The structural, electronic, optical, and mechanical properties of stoichiometric TaC(x)N(y = 1-x) were simulated using an ab initio calculation based on density functional theory (DFT) within the generalized gradient approximation. The calculations revealed the theoretical lattice parameter, density of states, refractive index, and elastic constants as a function of carbon and nitrogen content. TaC(x)N(y) films were subsequently produced on Si wafers using unbalanced magnetron sputtering. The structural, optical, and mechanical properties were measured using x-ray diffraction/transmission electron microscopy, vacuum ultraviolet spectroscopic ellipsometry, and nanoindentation, respectively. The computational and experimental properties were compared. The lattice parameter, the energy of the 2p bands in the density of states, and the energy of the interband transitions were found to decrease with increasing C content. No significant changes in the elastic constants were observed as a result of substituting N atoms with C atoms. The hardness and the elastic modulus were in the 40 and 380 GPa range, respectively. The experimental Young's modulus was much smaller than the computational one and this discrepancy was attributed to the nanocrystalline nature of the films. Also, the elastic constants were found to decrease dramatically for over-stoichiometric films.

This article reports on the use of real-time spectroscopic ellipsometry (RTSE) to (1) understand the growth process of ultrathin (10 nm thick) Ta–Si–N diffusion barriers and to (2) monitor their thermal stability up to a temperature of 800 °C. Thin films of Ta–Si–N diffusion barriers and Cu overlayers were deposited on Si(111) substrates using reactive unbalanced magnetron sputtering. In order to reduce roughness and interdiffusion between consecutive surfaces, a modulated low energy and high flux ion assistance was utilized. The initial part of the films (2 nm) of each layer was deposited with a high flux of low energy ions (<10eV) to reduce intermixing, while higher energies (between 40 and 130 eV) were utilized for the remainder of the layer to decrease the percolation thickness. RTSE data were simulated using the Drude-Lorentz model to obtain information about the growth mechanism and the conduction electron transport properties for these structures. The films were annealed at 800 °C and the diffusion of copper into silicon was evaluated by monitoring changes in the optical properties of the bilayers. The pseudodielectric function of the films was found to be altered whenever diffusion proceeded. Thermal stability at 800 °C was achieved for samples produced using the ion-assistance technique. The results deduced from RTSE were verified by characterizing the elemental composition of the as-deposited and heat-treated films using Rutherford backscattering and time-of-flight secondary ion mass spectrometry.