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In this paper, an experimental measurement of the diffusion constant of hydrogen in ruthenium is presented. By using a hydrogen indicative Y layer, placed under the Ru layer, the hydrogen flux through Ru was obtained by measuring the optical changes in the Y layer. We use optical transmission measurements to obtain the hydrogenation rate of Y in a temperature range from room temperature to 100 °C. We show that the measured hydrogenation rate is limited mainly by the hydrogen diffusion in Ru. These measurements were used to estimate the diffusion coefficient, D, and activation energy of hydrogen diffusion in Ru thin films to be D = 5.9 × 10−14 m2/s ∙ exp (-0.33 eV/ k B τ), with k B the Boltzmann constant and τ the temperature. Image 1 • Hydrogen diffusion through Ru films was studied. • Optical monitoring in transmission is used, with Y as H sensitive layer. • Pd capping layer ensures that H diffusion through Ru is limiting for H transport. • Diffusion constant and activation energy obtained in range 25–100 °C. [ABSTRACT FROM AUTHOR]

In this work, we investigated the influence of composition on the polycrystalline structure, elastic properties and fracture strength, of Zr x Si 1-x , Nb x Si 1-x, and Mo x Si 1-x free-standing thin films that were deposited by magnetron sputtering and subsequently annealed at 500 °C. Despite deviations from the stoichiometric composition, the crystalline structure of all films, except for the most Zr-rich Zr x Si 1-x , corresponded to their respective stoichiometric disilicide structures, without the formation of a second-phase. Off-stoichiometry was found to be accompanied by the presence of lattice defects and a decrease of the grain size, which bring about a lower tensile stress in the films. The dependence of the fracture strength on the composition was remarkably similar for the three silicides, with the lowest and highest strength values occurring for samples with 30% and 37–40% of metal content, respectively. The observed dependence of strength on composition was attributed to the combination of the Hall-Petch effect, changes in the morphology and strength of grain boundaries, and the enhancement of crystal plasticity due to lattice defects induced by off-stoichiometry. • Polycrystalline Me x Si 1-x (Me = Zr/Nb/Mo) membranes prepared by magnetron sputtering. • Relationship between composition, structure and mechanical properties studied. • Similar structural and mechanical behavior in all three studied silicides. • Strengthening due to lattice defects, grain refinement and zigzag-like GBs. [ABSTRACT FROM AUTHOR]

Abstract: An overview is given of the progress in thin film and surface physics involved in multilayered systems with nanometer scale periodicity. When properly engineered, these enable the synthesis of reflective optics for the Extreme UV wavelength range. Design, deposition, and analysis of these structures have been driven by the demanding application of Extreme UV photolithography. This review addresses the selection of the wavelength in relation to the optical constants of materials, the layer growth mechanisms and ways to reduce layer roughness and interlayer formation. Special attention is given to the development of thin diffusion barrier layers between the materials in the multilayers to enhance the optical contrast and to reduce the interdiffusion. Practical issues like reduction of multilayer induced stress and enlargement of the reflectance bandwidth are also discussed, as well as the development of capping layers to control surface physics processes occurring under EUV irradiation. A description of the multilayer deposition techniques is given and the deposition of multilayers on large, heavily curved optics for real lithography systems is discussed. [Copyright &y& Elsevier]

Abstract: We have investigated the co-adsorption of NH3 and SO2 on the quartz(0001) surface by TPD and RAIRS. A surface complex is formed as a result of various relative exposures of NH3 and SO2, irrespective of dosage order. However, the relative molecular composition of the complex is dependent on the dosage order. Higher desorption temperatures of NH3 and SO2 from the co-adsorbed systems, as compared with the isolated adsorbates, demonstrate mutual stabilization in the adlayer. Formation of hydrogen bonds between NH3 and SO2 is suggested based on the strong decrease in IR cross-section of the symmetric deformation and asymmetric stretch modes of NH3 upon co-adsorption of SO2 and of the symmetric stretch mode of SO2 upon co-adsorption of NH3. [Copyright &y& Elsevier]

Abstract: We investigate the influence of the Mo crystalline state (quasi-amorphous or crystalline) on the thermal stability of Mo/Si thin film multilayers with B4C diffusion barrier layers at either of the two interfaces. We find that multilayers containing amorphous Mo layers are more stable than those containing crystalline layers. This observation is in contrast to the case where Si3N4 diffusion barriers are used. Using X-ray diffraction, X-ray reflection and X-ray photo-electron spectroscopy we show that this difference can be attributed to the dissociation of B4C followed by diffusion of B in Mo. Due to the favorable thermodynamic properties of MoxBy compounds, the boron atoms react with the Mo layer, forming a MoxBy layer that effectively improves the multilayer thermal resistance. [ABSTRACT FROM AUTHOR]

Abstract: Chemical diffusion and interlayer formation in thin layers and at interfaces is of increasing influence in nanoscopic devices such as nano-electronics, magneto-optical storage and multilayer X-ray optics. We show that with the nitridation of reactive B4C/La interfaces, both the chemical and optical contrast can be greatly enhanced. Although interaction and diffusion of N2 from the substrate towards the adlayer does occur, this surfactant mediated growth contributes to chemical and optical interface properties that enable major reflectivity improvements of multilayer optics for 6.7< λ <7.0nm. [Copyright &y& Elsevier]

Abstract: Si/SiC multilayer systems for XUV reflection optics with a periodicity of 10–20nm were produced by sequential deposition of Si and implantation of 1keV ions. Only about 3% of the implanted carbon was transferred into the SiC, with a thin, 0.5–1nm, buried SiC layer being formed. We investigated the effect of thermal annealing on further completion of the carbide layer. For the annealing we used a vacuum furnace, a rapid thermal annealing system in argon atmosphere, and a scanning e-beam, for different temperatures, heating rates, and annealing durations. Annealing to a temperature as low as 600°C resulted in the formation of a 4.5nm smooth, amorphous carbide layer in the carbon-implanted region. However, annealing at a higher temperature, 1000°C, lead to the formation of a rough poly-crystalline carbide layer. The multilayers were characterized by grazing incidence X-ray reflectometry and cross section TEM. [Copyright &y& Elsevier]

Abstract: In this study, the molecular dynamics simulation method was employed to investigate the growth of silicon nitride films by using N+ ions, with energies of 50, 100, 150 and 200eV, to bombard an amorphous silicon surface at 300K. After an initial period of N+ bombardment, saturation of the number of N atoms deposited on the surface is observed, which is in agreement with experiments. During subsequent steady state deposition, a balance between uptake of N by the surface and sputtering of previously deposited N is established. The Si(N x ) (x =1–4) and N(Si y ) (y =1–3) bond configurations in the grown films are analyzed. [Copyright &y& Elsevier]