Current methodologies used for the inference of thin film stress through curvature measurements are strictly restricted to stress and curvature states which are assumed to remain uniform over the entire film/substrate...Current methodologies used for the inference of thin film stress through curvature measurements are strictly restricted to stress and curvature states which are assumed to remain uniform over the entire film/substrate system. By considering a circular thin film/substrate system subject to non-uniform, but axisymmetric misfit strain distributions in the thin film, we derived relations between the film stresses and the misfit strain, and between the plate system＇s curvatures and the misfit strain. These relations feature a “local” part which involves a direct dependence of the stress or curvature components on the misfit strain at the same point, and a “non-local” part which reflects the effect of misfit strain of other points on the location of scrutiny. Most notably, we also derived relations between the polar components of the film stress and those of system curvatures which allow for the experimental inference of such stresses from full-field curvature measurements in the presence of arbitrary radial non-uniformities. These relations also feature a “non-local” dependence on curvatures making a full-field measurement a necessity. Finally, it is shown that the interfacial shear tractions between the film and the substrate are proportional to the radial gradients of the first curvature invariant and can also be inferred experimentally.展开更多
For improving the polishing performance, in this article, the roles of a nonionic surfactant（Fatty alcohol polyoxyethylene ether） and H2O2 were investigated in the chemical mechanical planarization process, respecti...For improving the polishing performance, in this article, the roles of a nonionic surfactant（Fatty alcohol polyoxyethylene ether） and H2O2 were investigated in the chemical mechanical planarization process, respectively.Firstly, the effects of the nonionic surfactant on the within-wafer non-uniformity（WIWNU） and the surface roughness were mainly analyzed. In addition, the passivation ability of the slurry, which had no addition of BTA, was also discussed from the viewpoint of the static etch rate, electrochemical curve and residual step height under different concentrations of H2O2. The experimental results distinctly revealed that the nonionic surfactant introduced in the slurry improved the WIWNU and surface roughness, and that a 2 vol% was considered as an appropriate concentration relatively. When the concentration of H2O2 surpasses 3 vol%, the slurry will possess a relatively preferable passivation ability, which can effectively decrease the step height and contribute to acquiring a flat and smooth surface. Hence, based on the result of these experiments, the influences of the nonionic surfactant and H2O2 are further understood, which means the properties of slurry can be improved.展开更多
文摘Current methodologies used for the inference of thin film stress through curvature measurements are strictly restricted to stress and curvature states which are assumed to remain uniform over the entire film/substrate system. By considering a circular thin film/substrate system subject to non-uniform, but axisymmetric misfit strain distributions in the thin film, we derived relations between the film stresses and the misfit strain, and between the plate system＇s curvatures and the misfit strain. These relations feature a “local” part which involves a direct dependence of the stress or curvature components on the misfit strain at the same point, and a “non-local” part which reflects the effect of misfit strain of other points on the location of scrutiny. Most notably, we also derived relations between the polar components of the film stress and those of system curvatures which allow for the experimental inference of such stresses from full-field curvature measurements in the presence of arbitrary radial non-uniformities. These relations also feature a “non-local” dependence on curvatures making a full-field measurement a necessity. Finally, it is shown that the interfacial shear tractions between the film and the substrate are proportional to the radial gradients of the first curvature invariant and can also be inferred experimentally.
基金Project supported by the Special Project Items No.2 in National Long-Term Technology Development Plan,China(No.2009ZX02308)the Hebei Natural Science Foundation of China(No.E2013202247)the Natural Science Foundation of Hebei Province,China(No.E2014202147)
文摘For improving the polishing performance, in this article, the roles of a nonionic surfactant（Fatty alcohol polyoxyethylene ether） and H2O2 were investigated in the chemical mechanical planarization process, respectively.Firstly, the effects of the nonionic surfactant on the within-wafer non-uniformity（WIWNU） and the surface roughness were mainly analyzed. In addition, the passivation ability of the slurry, which had no addition of BTA, was also discussed from the viewpoint of the static etch rate, electrochemical curve and residual step height under different concentrations of H2O2. The experimental results distinctly revealed that the nonionic surfactant introduced in the slurry improved the WIWNU and surface roughness, and that a 2 vol% was considered as an appropriate concentration relatively. When the concentration of H2O2 surpasses 3 vol%, the slurry will possess a relatively preferable passivation ability, which can effectively decrease the step height and contribute to acquiring a flat and smooth surface. Hence, based on the result of these experiments, the influences of the nonionic surfactant and H2O2 are further understood, which means the properties of slurry can be improved.
