Jean-Marc Chaix

Copper-Line Topology Impact on the Reliability of SiOCH Low-

SiOCH low-k dielectrics introduction in copper interconnects associated to the critical dimensions reduction in sub-45-nm node technologies is a challenge for reliability engineers. Circuit wear-out linked to low-k dielectric breakdown is now becoming a major concern. With line-to-line spacing reduction, the control of the line shape and of the spacing uniformity within a wafer is becoming first-order parameters governing the low- k dielectric reliability. Improving the low- k reliability requires to discriminate each topological effect and to quantify its impact on the lifetime at product level. This paper demonstrates that the copper line shape induces a preferential breakdown of the dielectric close to the SiOCH/SiCN capping even at nominal voltage. The impact of the line edge roughness is studied with the introduction of a simple analytical model. Moreover, the impact of the roughness on the product lifetime has been quantified. It is demonstrated that the line-to-line spacing variation is less critical at the operational voltage than at high voltage stress. Finally, the impact of the spacing uniformity within the wafer and from wafer to wafer (reflecting the spacing fluctuation from product to product) on the Weibull shape is quantified and reported to be voltage-dependent in agreement with the experimental detail.

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Transmission Electron Microscopy (TEM) can be used to measure the size distribution and volume fraction of fine scale precipitates in metallic systems. However, such measurements suffer from a number of artefacts that need to be accounted for, related to the finite thickness of the TEM foil and to the projected observation in two dimensions of the microstructure. We present a correction procedure to describe the 3D distribution of disc-like particles and apply this method to the plate-like T1 precipitates in an Al-Li-Cu alloy in two ageing conditions showing different particle morphologies. The precipitates were imaged in a High-Angular Annular Dark Field Microscope (HAADF-STEM). The corrected size distribution is further used to determine the precipitate volume fraction. Atom probe tomography (APT) is finally utilised as an alternative way to measure the precipitate volume fraction and test the validity of the electron microscopy results.

for the 45-nm Technology Node and Beyond

The objective of this study is to process a bimaterial that combines the mechanical strength of a martensitic steel (X3CrNiMo13-4) and the wear and corrosion resistance of a cobalt base alloy (Stellite 6). The powder metallurgy route includes three steps: co-compaction, debinding, and pressureless co-sintering. The experimental approach consists in studying the compaction, the debinding and the sintering behavior of single materials (dimensional changes during sintering, microstructure, and hardness after sintering) before studying co-sintering. The co-sintering temperature range is defined from thermo-chemical calculations and single material sintering experiments especially for Stellite 6. Finally, the co-sintering ability is evaluated (green and final densities, shrinkage mismatch, coefficient of thermal expansion…) and the bimaterial sintering is studied. Despite the shrinkage mismatch of single materials, cohesion is achieved between the two materials through the infiltration of the supersolidus liquid from the Co base alloy to the steel and through the formation of an interdiffusion layer between the two materials characterized by a composition gradient.

Size distribution and volume fraction of T1 phase precipitates from TEM images: Direct measurements and related correction

Numerical and experimental studies have been undertaken to analyze three parameters controlling the compaction of granular media submitted to sinusoidal horizontal vibrations. We have characterized the influence of the dimensionless acceleration

Co-sintering and microstructural characterization of steel/cobalt base alloy bimaterials

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Parametric study of horizontally vibrated grain packings: comparison between Discrete Element Method and experimental results.

, the geometry of the container and the friction coefficients on the grain velocities and on the packing densities. Above a critical acceleration

Quantitative analysis of microstructure and modeling of sintering

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Elaboration of (Steel/Cemented Carbide) Multimaterial by Powder Metallurgy

, the velocities increases with

Compression and Sintering of Powder Mixtures: Experiments and Modelling

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Densification and microstructure changes of micron size nickel powder during direct induction sintering

. For low values of