Electrografting is a powerful and versatile technique for modifying and decorating conducting surfaces with organic matter Mainly based on the electro-induced polymerization of dissolved electro-active monomers on metallic or semiconducting surfaces, it finds applications in various fields including biocompatibility, protection against corrosion, lubrication, soldering, functionalization, adhesion, and template chemistry Starting from experimental observations, this Review highlights the mechanism of the formation of covalent metal-carbon bonds by electro-induced processes, together with major applications such as derivatization of conducting surfaces with biomolecules that can be used in biosensing, lubrication of low-level electrical contacts, reversible trapping of ionic waste on reactive electrografted surfaces as an alternative to ion-exchange resins, and localized modification of conducting surfaces, a one-step process providing submicrometer grafted areas and which is used in microelectronics

Molecule‐to‐Metal Bonds: Electrografting Polymers on Conducting Surfaces

A quantitative analysis of blurring and its dependence on the stencil–substrate gap and the deposition parameters in stencil lithography, a high resolution shadow mask technique, is presented. The blurring is manifested in two ways: first, the structure directly deposited on the substrate is larger than the stencil aperture due to geometrical factors, and second, a halo of material is formed surrounding the deposited structure, presumably due to surface diffusion. The blurring is studied as a function of the gap using dedicated stencils that allow a controlled variation of the gap. Our results show a linear relationship between the gap and the blurring of the directly deposited structure. In our configuration, with a material source of ~5 mm and a source–substrate distance of 1 m, we find that a gap size of ~10 µm enlarges the directly deposited structures by ~50 nm. The measured halo varies from 0.2 to 3 µm in width depending on the gap, the stencil aperture size and other deposition parameters. We also show that the blurring can be reduced by decreasing the nominal deposition thickness, the deposition rate and the substrate temperature.

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Analysis of the blurring in stencil lithography

Multi-element (AlCrTaTiZr)N coatings are prepared by reactive RF magnetron sputtering. The influence of substrate bias (0 to −200 V) on the deposition rate, composition, structure and mechanical properties of these coatings is investigated. A reduction in both deposition rate and Al concentration is observed with increasing substrate bias. The grounded substrate is found to possess a columnar structure. The columnar structure is not so apparent in the denser coatings deposited at an applied substrate bias of −150 V. Furthermore, a minimum in coating roughness is found to occur at the intermediate substrate bias of −100 V. All the (AlCrTaTiZr)N coatings appear to have a single FCC structure from XRD analysis. Furthermore, it is determined from XRD that there is an increase in both (111) peak intensity and grain size, and a decrease in the lattice strain, for increasing substrate bias. The residual stress, hardness, elastic modulus and toughness of the coatings are found to be greatly enhanced by the substrate bias. The highest hardness and elastic modulus of approximately 36 Gpa and 360 GPa, respectively, were obtained at a substrate bias of −150 V.

https://iopscience.iop.org/article/10.1088/0022-3727/39/21/019/pdf

Effect of substrate bias on the structure and properties of multi-element (AlCrTaTiZr)N coatings

We studied the variation in perpendicular magnetic anisotropy of (111) textured $\mathrm{Au}/N\ifmmode\times\else\texttimes\fi{}[\mathrm{Co}/\mathrm{Ni}]/\mathrm{Au}$ films as a function of the number of bilayer repeats $N$. The ferromagnetic resonance and superconducting quantum interference device magnetometer measurements show that the perpendicular magnetic anisotropy of Co/Ni multilayers first increases with $N$ for $N\ensuremath{\le}10$ and then moderately decreases for $Ng10$. The model we propose reveals that the decrease of the anisotropy for $Nl10$ is predominantly due to the reduction in the magnetoelastic and magnetocrystalline anisotropies. A moderate decrease in the perpendicular magnetic anisotropy for $Ng10$ is due to the reduction in the magnetocrystalline and the surface anisotropies. To calculate the contribution of magnetoelastic anisotropy in the Co/Ni multilayers, in-plane and out-of-plane x-ray diffraction measurements are performed to determine the spacing between Co/Ni (111) and (220) planes. The magnetocrystalline bulk anisotropy is estimated from the difference in the perpendicular and parallel $g$ factors of Co/Ni multilayers that are measured using the in-plane and out-of-plane ferromagnetic resonance measurements. Transmission electron microscopy has been used to estimate the multilayer film roughness. These values are used to calculate the roughness-induced surface and magnetocrystalline anisotropy coefficients as a function of $N$.

Origin of perpendicular magnetic anisotropy in Co/Ni multilayers

Preparation of thin films and nanostructured coatings for clean tech applications: A primer

Principes de base des procedes de depot physique en phase vapeur (evaporation, pulverisation, depot ionique). Comparaison des avantages et des inconvenients des trois types de depot. Applications actuelles de chacun d'eux et perspectives d'applications futures et de developpement

P. C. Johnson

Papers

Physical vapor deposition of thin films