14 research outputs found

    Copper-Line Topology Impact on the Reliability of SiOCH Low-k for the 45-nm Technology Node and Beyond

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    International audienceSiOCH 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-fine 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

    3D Printing Cellulose Hydrogels Using LASER Induced Thermal Gelation

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    A 3D printer was developed for the 3D printing of cellulose hydrogels using open source software and simple 3D printer hardware. Using a temperature-based sol-gel transition of cellulose dissolved in aqueous solutions of sodium hydroxide (NaOH) and urea, a three-dimensional gel can be created by moving a focused laser beam across a bath of the cellulose solution and lowering the print stage after every layer. A line width of 100–150 ”m and layer thickness of 25 ”m of the printed part could be achieved. No delamination between printed layers occurred and no additional support material was needed to create free hanging structures due to suspending the printed part in printing liquid. By adding cellulose powder to the solution, the gelation temperature, the gel strength and stiffness can be manipulated while maintaining a high internal porosity of the gel. A laser power of 100 mW was found to produce the highest quality print with an accurate representation of the previously designed part. Lower power settings (80 mW) produced insufficient gelation and as a result reduced print accuracy while higher power settings (120 mW) caused the gel to bur

    Lifetime measurement of the six-quasiparticle isomer in 140Nd and evidence for an isomer above the 19/2+ state in 139Nd

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    The lifetime of the recently discovered six-quasiparticle (6-qp) isomer in 140Nd has been measured using the 126Te(18O, 4n) reaction and the pulsed-beam technique at the Institut de Physique NuclĂ©aire (IPN) Orsay. The deduced lifetime of the 6-qp isomer in 140Nd of 1.23(7)ÎŒs supports the 20+ spin-parity assignment to the isomeric state which is based on a spherical configuration that coexists with the triaxial bands observed in this spin range. Evidence for delayed components for the transitions below the 19/2+ state in 139Nd was observed, with an apparent half-life of 272(4)n
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