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18066
01/04/2018

Computational fluid dynamics simulation of the ALD of alumina from TMA and H2O in a commercial reactor

G.P.GAKIS, H.VERGNES, E.SCHEID, C.VAHLAS, B.CAUSSAT, A.BOUDOUVIS

LGC, MPN, CIRIMAT, NTUA

Revue Scientifique : Chemical Engineering Research and Design: Transactions of the Institution of Chemical Engineers Part A, Vol.132, pp.795-811, Avril 2018 , N° 18066

Lien : https://hal.archives-ouvertes.fr/hal-01730196

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A three-dimensional Computational Fluid Dynamics model is built for a commercial Atomic Layer Deposition (ALD) reactor, designed to treat large area 20 cm substrates. The model aims to investigate the effect of the reactor geometry and process parameters on the gas flow and temperature fields, and on the species distribution on the heated substrate surface, for the deposition of Al2O3 films from trimethyl aluminum and H2O. The investigation is performed in transient conditions, without considering any surface reaction. A second CFD model is developed for the feeding system of the reactor, in order to calculate the unknown reactant inlet flow rates. The two models are coupled via a computational strategy dictated by the available experimental measurements. Results show that a purging flow entering the reactor through its loading door affects the flow field above the substrate surface and causes non-uniformity in the temperature and reactants concentration on the substrate surface. During the TMA pulse, a recirculation sets in above the substrate surface, leading to a non-uniform distribution of species on the surface.

142837
18056
28/03/2018

Submicron polymer optical waveguides on CYTOP for visible range operation

M.DIEZ GARCIA, S.JOLY, V.RAIMBAULT, J.B.DOUCET, L.OYHENART, L.BECHOU, C.DEJOUS

IMS Bordeaux, MICA, TEAM

Manifestation avec acte : Europtrode ( Europtrode ) 2018 du 25 mars au 28 mars 2018, Naples (Italie), Mars 2018 , N° 18056

Lien : https://hal.archives-ouvertes.fr/hal-01720764

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142797
18073
21/03/2018

Dopant Activation in Ultra-thin SiGeOI and SOI layers characterised by Differential Hall Effect

R.DAUBRIAC, E.SCHEID, S.JOBLOT, R.BENEYTON, P.ACOSTA ALBA, S.KERDILES, F.CRISTIANO

MPN, ST Microelectronics, CEA-LETI

Manifestation avec acte : Joint International EUROSOI Workshop and International Conference on Ultimate Integration on Silicon ( EUROSOI-ULIS ) 2018 du 19 mars au 21 mars 2018, Grenade (Espagne), Mars 2018, 2p. , N° 18073

Lien : https://hal.laas.fr/hal-01735436

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The reduction of the contact resistance RC is one of the most challenging issues related to the miniaturisation of advanced MOSFET architectures, including FDSOI technology (Fully Depleted Silicon-On-Insulator). RC strongly depends on the active dopant concentration at the semiconductor/salicide interface. It is therefore essential that electrical activation at different depths within a doped layer is reliably determined to optimise the fabrication processes. In this paper, we firstly present a Differential Hall Effect (DHE) method which allows measuring the active dopant concentration profile close to the surface with nm resolution for ultra-shallow doped Si1-xGex and Si layers. Then, we present DHE measurements made on junctions processed with advanced techniques, including nsec LTA and msec DSA anneals.

142935
18068
14/03/2018

A Differential Hall Effect method with sub-nanometre resolution for active dopant concentration profiling in ultra-thin Si 1-x Ge x and Si doped layers

R.DAUBRIAC, E.SCHEID, S.JOBLOT, R.BENEYTON, P.ACOSTA ALBA, S.KERDILES, F.CRISTIANO

MPN, ST Microelectronics, CEA-LETI

Rapport LAAS N°18068, Mars 2018, 34p.

Lien : https://hal.laas.fr/hal-01730674

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In this paper, we present an enhanced Differential Hall Effect method (DHE) for Si and SiGe ultrathin layers for the investigation of dopant activation in the surface region with sub-nanometre resolution. In the case of SiGe case, which constitutes the most challenging process, we show the reliability of the SC1 chemical solution (NH4OH:H2O2:H2O) thanks to its slow etch rate, stoichiometry conservation and low roughness generation. The reliability of a complete DHE procedure, with an etching step as small as 0.5 nm, is demonstrated on a dedicated 20 nm-thick SiGe test structure fabricated by CVD and uniformly doped in situ during growth. The developed method is finally applied to the investigation of dopant activation achieved by advanced annealing methods (including millisecond and nanosecond laser anneal) in two material systems: 6 nm-thick SiGeOI and 11 nm-thick SOI. In both cases, DHE is shown to be a unique sensitive characterisation technique for a detailed investigation of dopant activation in ultra-shallow layers, providing sub-nm resolution for both dopant concentration and carrier mobility depth profiles.

142839
18046
09/03/2018

Ballistic Majorana nanowire devices

O.GUL, H.ZHANG, J.BOMMER, M.DE MOOR, D.CAR, E.P.A.M.BAKKERS, S.PLISSARD, A.GERESDI, K.WATANABE, T.TANIGUCHI, L.P.KOUWENHOVEN

Delft, Eindhoven, MPN, NIMS, Tsukuba

Revue Scientifique : Nature Nanotechnology, Vol.13, N°3, pp.192-197, Mars 2018 , N° 18046

Lien : https://hal.laas.fr/hal-01712989

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Majorana modes are zero-energy excitations of a topological superconductor that exhibit non- Abelian statistics 1–3 . Following proposals for their detection in a semiconductor nanowire cou- pled to an s-wave superconductor 4,5 , several tun- neling experiments reported characteristic Majo- rana signatures 6–11 . Reducing disorder has been a prime challenge for these experiments because disorder can mimic the zero-energy signatures of Majoranas 12–16 , and renders the topological prop- erties inaccessible 17–20 . Here, we show character- istic Majorana signatures in InSb nanowire de- vices exhibiting clear ballistic transport proper- ties. Application of a magnetic field and spatial control of carrier density using local gates gen- erates a zero bias peak that is rigid over a large region in the parameter space of chemical poten- tial, Zeeman energy, and tunnel barrier potential. The reduction of disorder allows us to resolve sep- arate regions in the parameter space with and without a zero bias peak, indicating topologically distinct phases. These observations are consistent with the Majorana theory in a ballistic system 21 , and exclude for the first time the known alter- native explanations that invoke disorder 12–16 or a nonuniform chemical potential

142690
18022
27/02/2018

Two-photon lithography and microscopy of 3D hydrogel scaffolds for neuronal cell growth

A.ACCARDO, MC.BLATCHE, R.COURSON, I.LOUBINOUX, C.VIEU, L.MALAQUIN

ELIA, I2C, TEAM, INSERM

Revue Scientifique : Biomedical Physics & Engineering Express, Février 2018 , N° 18022

Lien : https://hal.laas.fr/hal-01698486

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3D fabrication techniques are rapidly expanding in the field of scaffold development for cell culture and tissue engineering. Herein we report the realization of free-standing PEGDA hydrogel architectures by using two-photon lithography. The morphological and immunofluorescence characterization of neuro2A cells revealed a tridimensional colonization featuring multiple neuritic extensions per cell as well as the expression of β-tubulin neuronal marker and actin microfilaments. The results open new perspectives in the continuous quest for structured biomaterials able to provide a favorable environment to cells and at the same time not interfering with imaging protocols necessary for a clear scenario of the cell seeding.

142468
17515
07/02/2018

Lab-on-Chip for DNA Analysis With Resolution Length of 3 bp and Concentration of 10 nM

B.CHAMI, M.SOCOL, R.MALBEC, A.BANCAUD

MILE, MICA

Affiche/Poster : MICROFLUIDICS2017 - Ecole thématique ( ) 2017 du 25 juin au 30 juin 2017, Carcans Maubuisson (France), Février 2018, 1p. , N° 17515

Lien : https://hal.archives-ouvertes.fr/hal-01686185

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142319
18070
01/02/2018

Measuring Interfacial Polymerization Kinetics Using Microfluidic Interferometry

A.NOWBAHAR, V.MANSARD, J.MECCA, T.ARROWOOD, T.SQUIRES

Univ. of California, MEMS, The Dow Chemical

Revue Scientifique : Journal of the American Chemical Society, Vol.140, N°9, pp.3173-3176, Février 2018 , N° 18070

Lien : https://hal.archives-ouvertes.fr/hal-01734561

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Interfacial polymerization is used in a range of elds, both academic and industrial, for the production of bers, capsules , and lms. Despite its widespread use, measuring the reaction kinetics of interfacial polymerization has remained a challenge. For example, reaction kinetics for polyamide reverse osmosis membranes are dicult to obtain and rarely reported due to the thinness of lms, and rapidity of their formation at the liquid-liquid interface. Here, polyamide lm formation is studied using a microuidic, interferometry-based technique to measure monomer concentration near the interface as the reaction occurs. Our results are consistent with a polymeriza-tion reaction that is initially controlled by a reaction-diusion boundary layer within the organic phase. Using simple scaling arguments to analyze our data, we report the rst measurements of the reaction rate constant for this system.

142873
18007
01/02/2018

Ciguatoxins activate the Calcineurin signalling pathway in Yeasts: Potential for development of an alternative detection tool?

H.MARTIN-YKEN, C.GIRONDE, S.DERICK, H.TAIANA DARIUS, C.FURGER, D.LAURENT, M.CHINAIN

LISBP, MH2F, ILM, Papeete, Toulouse III

Revue Scientifique : Environmental Research, Vol.162, pp.144-151, Février 2018 , N° 18007

Lien : https://hal.archives-ouvertes.fr/hal-01680541

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Ciguatoxins (CTXs) are lipid-soluble polyether compounds produced by dinoflagellates from the genus Gambierdiscus spp. typically found in tropical and subtropical zones. This endemic area is however rapidly expanding due to environmental perturbations, and both toxic Gambierdiscus spp. and ciguatoxic fishes have been recently identified in the North Atlantic Ocean (Madeira and Canary islands) and Mediterranean Sea. Ciguatoxins bind to Voltage Gated Sodium Channels on the membranes of sensory neurons, causing Ciguatera Fish Poisoning (CFP) in humans, a disease characterized by a complex array of gastrointestinal, neurological, neuropsychological, and cardiovascular symptoms. Although CFP is the most frequently reported non bacterial food-borne poisoning worldwide, there is still no simple and quick way of detecting CTXs in contaminated samples. In the prospect to engineer rapid and easy-to-use CTXs live cells-based tests, we have studied the effects of CTXs on the yeast Saccharomyces cerevisiae, a unicellular model which displays a remarkable conservation of cellular signalling pathways with higher eukaryotes. Taking advantage of this high level of conservation, yeast strains have been genetically modified to encode specific transcriptional reporters responding to CTXs exposure. These yeast strains were further exposed to different concentrations of either purified CTX or micro-algal extracts containing CTXs. Our data establish that CTXs are not cytotoxic to yeast cells even at concentrations as high as 1μM, and cause an increase in the level of free intracellular calcium in yeast cells. Concomitantly, a dose-dependent activation of the calcineurin signalling pathway is observed, as assessed by measuring the activity of specific transcriptional reporters in the engineered yeast strains. These findings offer promising prospects regarding the potential development of a yeast cells-based test that could supplement or, in some instances, replace current methods for the routine detection of CTXs in seafood products

142177
18012
30/01/2018

Accelerated transport of particles in confined channels with high roughness amplitude

H.RANCHON, J.CACHEUX, B.REIG, O.LIOT, P.TEERAPANICH, T.LEICHLE, P.JOSEPH, A.BANCAUD

MILE, MEMS, TEAM

Revue Scientifique : Langmuir, Vol.34, N°4, pp.1394-1399, Janvier 2018 , N° 18012

Lien : https://hal.archives-ouvertes.fr/hal-01682628

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We investigate the pressure-driven transport of particles 200 or 300 nm in diameter in shallow microfluidic channels ∼1 μm in height with a bottom wall characterized by a high roughness amplitude of ∼100 nm. This study starts with the description of an assay to generate cracks in hydrophilic thin polymer films together with a structural characterization of these corrugations. Microfluidic chips of variable height are then assembled on top of these rough surfaces, and the transport of particles is assessed by measuring the velocity distribution function for a set of pressure drops. We specifically detect anomalous transport properties for rough surfaces. The maximum particle velocity at the centerline of the channel is comparable to that obtained with smooth surfaces, but the average particle velocity increases nonlinearly with the flow rate. We suggest that the change in the boundary condition at the rough wall is not sufficient to account for our data and that the occurrence of contacts between the particle and the surface transports the particle away from the wall and speeds up its motion. We finally draw perspectives for the separation by field-flow fractionation.

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