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The partial pressure of CO 2 (pCO 2 ) and dissolved inorganic carbon (DIC) were monitored in shallow coastal waters located inside and outside giant kelp beds ( Macrocystis pyrifera ) located in the Kerguelen Archipelago (Southern Ocean). Photosynthesis and respiration by microplankton and kelp lead to marked pCO 2 and DIC diel cycles. Daily variations of pCO 2 and DIC are significant in the spring and summer, but absent in the winter, reflecting the seasonal cycle of biological activity in the kelp beds. If the kelp beds seem to favour the onset of phytoplankton blooms, most of the primary production inside the kelp beds is due to the kelp itself. The primary production of Macrocystis kelp beds in the Sub-Antarctic high-nutrient, low-chlorophyll (HNLC) waters off the Kerguelen Archipelago is elevated and closely linked to light availability. This production is significant from October to March and reaches its climax in December at the solar radiation maximum.

The formation of a copper silicide interfacial layer by surface reaction in a plasma enhanced chemical vapour deposition (PECVD) system has been studied. Tri-methyl silane (TMS, SiH(CH"3)"3) has been employed as the Si source as an alternative to more conventional silane (SiH"4) approach. TMS precursor has been chosen due to improved control of Si penetration into the copper [S. Chhun, L.G. Gosset, N. Casanova, J.F. Guillaumond, P. Dumont-Girard, X. Fedespiel, R. Pantel, V. Arnal, L. Arnaud, J. Torres, Microelectronic Engineering 76 (2004) 106-112]. AFM, SIMS, light scattering, FT-IR spectroscopy and dielectric constant measurements were performed on various stacks to evaluate CuSiN formation. Resistance, leakage, and electromigration (EM) reliability characterization were performed on test structures based on 65nm design rules. Nitridation step in silicidation process was shown to have positive impact on EM reliability, minimizing the line resistance increase.

X-ray reflectivity (XRR), X-ray fluorescence (XRF) and small angle X-ray scattering (SAXS) techniques are used to the monitoring of Cu/porous low κ processes, which are developed for the next generation (≤65 nm) integrated circuits. Sensitivity of XRR and XRF is sufficient to detect drifts of the copper barrier layer, copper seed layer and Cu CMP (chemical–mechanical polishing) processes. Their metrology key parameters comply with production requirements. SAXS allows determining the pore structure of low κ films: average pore size and pore size distribution.

Self-aligned barriers have been widely investigated in the replacement of standard PECVD dielectric liners to decrease coupling capacitance. As an alternative to CVD or electroless approaches, a two step process based on the modification of the Cu surface is proposed. This technique consists first in enriching Cu surface with Si atoms followed by a nitridation step to complete the so called CuSiN self-aligned barrier. In this paper, the silicidation mechanism is described and the crucial role of the nitridation step is demonstrated in terms of barrier stability under electrical stress. CuSiN efficiency against Cu diffusion and oxidation is also evidenced. Compared to a standard SiCN barrier, CuSiN self-aligned barriers revealed a gain of at least 3 decades in time-dependent dielectric breakdown lifetime and up to 7% decrease in intra-level coupling capacitance.

Accurate and reliable in-line monitoring of the different films thickness that occur throughout the integrated circuit manufacturing process is mandatory to develop and produce advanced microelectronic devices. X-ray reflectivity (XRR) is a fundamental and suitable metrology technique to precisely determine the thickness of both transparent and metallic thin films. Furthermore, XRR is very sensitive to surface and interface roughness, and also provides information about the film density. X-ray fluorescence (XRF) is currently used as a metrology technique to control the thickness and the elemental composition of relatively thick films. The performance of a new in-line metrology tool, which gathers XRR and XRF data to monitor film thickness, has been assessed. Results on the monitoring of high κ thin films, low κ materials, copper barrier and copper seed layers are presented.

This paper presents a new technique using energy filtered TEM (EFTEM) for inelastic electron scattering contrast imaging of Germanium distribution in Si–SiGe nanostructures. Comparing electron energy loss spectra (EELS) obtained in both SiGe and Si single crystals, we found a spectrum area strongly sensitive to the presence of Ge in the range [50–100 eV]. In this energy loss window, EELS spectrum shows a smooth steeply shaped background strongly depending on Ge concentration. Germanium mapping inside SiGe can thus be performed through imaging of the EELS background slope variation, obtained by processing the ratio of two energy filtered TEM images, respectively, acquired at 90 and 60 eV. This technique gives contrasted images strongly similar to those obtained using STEM Z-contrast, but presenting some advantages: elastic interaction (diffraction) is eliminated, and contrast is insensitive to polycrystalline grains orientation or specimen thickness. Moreover, since the extracted signal is a spectral signature (inelastic energy loss) we demonstrate that it can be used for observation and quantification of Ge concentration depth profile of SiGe buried layers.

A new method to determine the concentration of germanium in Si(1-x) Ge(x) single crystals is presented. It is based on extinction distance measurements by means of convergent beam electron diffraction (CBED). The two-beam condition CBED intensity oscillation (the so-called rocking curve) is measured for the 004 diffracted beam and compared with a numerical simulation. Using the two-beam dynamical diffraction approximation theory, this approach yields very precise values for both specimen thickness and effective extinction distance (Ultramicroscopy 87 (2001) 5). First a theoretical extinction distance zetag(x) for strain relaxed Si(1-x)Ge(x) is calculated assuming a solid solution and using tabulated atomic scattering factors of silicon and germanium atoms. It is found that for single crystals zetag(x) decreases from 156 nm in pure silicon to 90 nm in pure germanium. Measurements on calibrated strain relaxed SiGe layers with variable germanium concentrations show an excellent agreement between experimental and calculated extinction distances zetag(x). As a consequence the experimental extinction distance zetag(x) becomes an indirect measure of the germanium concentration with a 1-2 at % sensitivity. The method turns out to be insensitive to strain as experimental zetag(x) values obtained on strained SiGe layers fit the theoretical extinction distance curve calculated for strain relaxed SiGe.

We report first direct measurements of the partial pressure of CO2 (pCO2) within Antarctic pack sea ice brines and related CO2 fluxes across the air-ice interface. From late winter to summer, brines encased in the ice change from a CO2 large oversaturation, relative to the atmosphere, to a marked undersaturation while the underlying oceanic waters remains slightly oversaturated. The decrease from winter to summer of pCO2 in the brines is driven by dilution with melting ice, dissolution of carbonate crystals, and net primary production. As the ice warms, its permeability increases, allowing CO2 transfer at the air-sea ice interface. The sea ice changes from a transient source to a sink for atmospheric CO2. We upscale these observations to the whole Antarctic sea ice cover using the NEMO-LIM3 large-scale sea ice-ocean and provide first estimates of spring and summer CO2 uptake from the atmosphere by Antarctic sea ice. Over the spring-summer period, the Antarctic sea ice cover is a net sink of atmospheric CO2 of 0.029 Pg C, about 58% of the estimated annual uptake from the Southern Ocean. Sea ice then contributes significantly to the sink of CO2 of the Southern Ocean.

A new method for measuring thickness and extinction distance of single crystals based on computed adjustment of measured and calculated CBED pattern intensity profiles is presented and discussed. The experimental beam intensity distribution is measured from an energy filtered CBED pattern recorded on a CCD camera. The calculated profile is based on dynamical diffraction theory, and with the two-beam approximation the analytical expression contains only two free parameters: specimen thickness t and extinction distance xig. Parameter refinement through minimization of the difference between experimental and calculated intensity profiles is carried out using Origin 5.0 software from Microcal. The iterative procedure always converges to a unique solution in a few seconds, yielding an accurate value for both thickness and extinction distance. The method is extensively tested on silicon using the (0 0 4) Bragg reflection. On specimens in the usual TEM thickness range, the method gives result similar to the conventional (P.M. Kelly et al., Phys. Stat. Sol. A31 (1975) 771; S.M. Allen, Philos. Mag. A 43 (1981) 325) graphical methods, both based on the measurement of fringe spacing. Moreover, it is shown that the calculation matches perfectly both the positions of the minimums and maximums as well as the amplitude of maximums. For any single intensity profile, specimen thickness and extinction distance can be determined with a precision of about 0.2%. A statistical comparison of our method with the Kelly and Allen techniques, based on more than 50 experiments, shows an improvement in measured extinction distance dispersion. Using 197 keV electrons, and liquid-nitrogen cryo-holder, the new technique yields an experimental value of 161+/-3 nm for the extinction distance for silicon with the (0 0 4) Bragg reflection. The equivalent tabulated value at 0 K is about 156 nm. Using the Kelly and Allen methods, the extinction distance is found to be 162+/-6 nm. The improvement in precision is a direct consequence of matching the intensity profile envelope, which contains information on the extinction distance. Also the accuracy of thickness determination is improved and is around 0.5 to 1% for common specimen thickness. The minimum measurable sample thickness is shown to be two to three times thinner than with the Kelly and Allen methods (0.3 xig, as opposed to 0.8 xig). With no independent calculation of the extinction distance needed, the method is also applicable on unknown crystals. The method is fast, simple and can be easily automated.

The survival of human enteric bacteria in the aquatic environment has attracted much interest in view of its public health significance. Untreated sewage has been released from Dumont d'Urville station, Antarctica, into the Southern Ocean for several years. The spatial distribution of faecal bacteria indicators was investigated in summer ice-free seawater near the French Base station of the Adelie land area. A complementary seasonal survey of the occurrence of faecal coliform bacteria was conducted in seawater under the winter sea ice in a specific station. Relatively high bacterial densities (maximum 103 CFU 100 ml−1) were found in seawater surrounding the sewage outfall. However, the contamination decreased rapidly with increasing distance from the outfall. In all samples collected further than 2 km, the bacterial indicators were absent or present in very small numbers. Faecal coliforms were not detected in samples collected at pristine sites. Despite these relatively low contamination levels, faecal bacteria were always detected in the vicinity of the sewage outfall during the seasonal survey conducted in ice and under-ice seawater.

An epitaxial Si grown multi-layer stack consisting of boron delta-doped layers separated by 6.4 nm thick undoped films has been profiled using a Cameca IMS Wf magnetic SIMS. Using low energy oblique O 2 + beam, the boron depth resolution is improved from 1.66 nm/decade at 500 eV down to 0.83 nm/decade at 150 eV. At very low impact energy O 2 + bombardment induces a near full oxidation of silicon and oxygen flooding is then no more needed in the analytical chamber to get a smooth sputtering of silicon at 45° incidence angle.

A short overview of the biodiversity of Antarctic marine bacteria is given with respect to morphology and metabolic activity. The importance of spatial and temporal variability is described. The physiological adaptation and ecological function of Antarctic marine bacterioplankton are discussed.

The distributions of phytoplankton biomass and bacterial populations were investigated at 37 statlons on the continental shelf of Terre Adelie (Antarctica) during Austral summer 1989. Despite a potentially favourable environment, phytoplankton biomass was relatively low. Surface chlorophyll a values ranged from 1.2 mg m-3 in the coastal area, with a maximum of 2.5 mg m-3 in the vicinity of the penguin rookeries, to only 0.2 mg m-3 70 km offshore. In the Pointe Geologie Archipelago, diatoms larger than 10 pm were predominant and represented more than 80 'h, of the total biomass. In offshore waters, these large cells represented only 38 % of the total biomass with 59 % of the biomass in the 1 to 10 fraction. Total bacterial abundance ranged from 9 4 X 10' to 1.0 x 10" cells m-3 and heterotrophic bacteria ranged from 1.4 x 106 to 7.7 X 10' colony forming units m-' Frequency of dividing cells ranged from 0.8 to 6.6 %. The highest numbers of heterotrophic bacteria were recorded in the immediate vicinity of penguin rookeries and the lowest in offshore waters. Bacterial biomass represents between 2 to 15 % of total microbial biomass in offshore waters and up to 30 O/ O in the coastal area. There was no direct correlation between bacterial and phytoplanktonic standing stocks. This lack of relationship can be explained by considering the differences in scale. It is suggested that in the coastal area where large diatoms are dominant, the bacteria are mainly dependant on organic matter introduced by bird manuring. On the other hand, in offshore waters where the dominant phytoplankton fraction under 10 pm represents a large part of the microbial loop, an indirect relationship between algae and bacteria may be expected.

This paper presents the synthesis of epitaxial silicon (Si) nanoblades of controlled dimensions (thickness 50nm, width 200nm to 2μm) obtained by catalytic growth in a tunnel of confinement. The fabrication of horizontal cavities containing the catalyst slug is first described to show how the tunnel empty space is formed using an amorphous germanium sacrificial layer. These cavities served as a template to guide VLS (Vapor-Liquid-Solid) growth of crystalline Si standing on an amorphous substrate. The resulting self-assembled Si nanoribbons can be regarded as localized silicon-on-insulator (SOI) film that can be reproduced in the vertical direction to enable three-dimensional integration. The nature of the grown silicon film is characterized by scanning and transmission electron microscopy (SEM and TEM) as well as by electron backscattered diffraction (EBSD).

Observations of the short-term changes of seawater bacterioplankton were carried out during the summer of 1988 in Antarctic coastal surface waters. The studies were designed to compare the variations of bacterioplankton in freemoving and enclosed seawater. Even when a diurnal cycle is present the data collected from the enclosed seawater experiments remain much more constant than the corresponding data in free-moving seawater. The wide range of parameters used in the two experiments reveals common properties which illustrate the major role of displacements of water masses at a fixed sampling station in the temporal changes observed in free-moving Antarctic coastal seawater.

The short-term effects of giant kelp Macrocystis pyrifera C.A. Agardh on the growth of subantarctic bacterial microflora were followed under various seasonal conditions in coastal seawater of the Kerguelen Archipelago. Artificial degradation experiments were carried out in 3-m 3 tanks (daily sampling allowed a regular survey of bacterial changes in the supplemented seawater). The results clearly revealed a significant response of the subantarctic bacterial community to macrophyte addition. Bacteria grew rapidly on freshly harvested or stranded kelp. Doubling time had a mean value of 40 h for total bacteria and 8 h for heterotrophic bacteria. Bacterial growth peaked within the first 3–5 days but declined thereafter. Both total and heterotrophic bacterial increases were higher in stranded or detritic kelp experiments than in freshly harvested kelp experiments. The amphipod Parathemisto gaudichaudii Guerin was used to assess the stimulating effect of macrofaunal breakdown on the bacterial decomposition of the kelp.

This paper demonstrates the possibility to use a bottom-up front-end (FE) architecture for sub-32 nm CMOS nodes with a new 3D approach in front-end flow. This architecture based on the so called FRETCH (film replacement etching through contact hole) solution [1] is compatible to adapt a specific device before or after electrical test. To address the full 3D in FE concept of buried integration will be proposed by using e-beam and HSQ material. Finally a novel integration scheme fully compatible with conventional bulk flow with one mask will be depicted allowing a self assembly structure and reducing significantly the process variability.

The short term degradation of ‘Arabian light’ crude oil was followed under various seasonal conditions in coastal seawater at Iles Kerguelen. Artificial degradation experiments were carried out in 3 m3 tanks. In situ experiments were conducted in free-floating, semi-enclosed chambers permitting direct contact between the crude oil and the marine environment. Daily sampling allowed a regular survey of the bacterial changes of the oil contaminated seawater. All samples were analysed for total bacteria, heterotrophic viable microflora and hydrocarbon utilizing microflora. At the end of experiments, the remaining oil was carefully collected for rough quantitative estimation of hydrocarbon degradation. All the results clearly revealed a significant increase in the three types of bacterial microflora after the addition of crude oil. However, the data suggest that the initial state of the bacterial communities is important. Thus, the seasonal variations in the bacterial responses to hydrocarbon addition can be related to the differences in the natural bacterial populations involved. In all cases the wall effects observed in batch systems were reduced with in situ incubations.

This paper presents a cost-effective 45-nm technology platform, primarily designed to serve the wireless multimedia and consumer electronics needs. This platform features low power transistors operating at a nominal voltage of 1.1V, an ultra low k dielectric (k~2.5) with up to 9 Cu metal layers and 0.25/0.3/0.37mum2 SRAM cells. This platform also features an optional third gate oxide for either higher speed or active power mitigation. This technology has been developed on the (100)-oriented substrate with a key focus on process simplicity. Transistor improvement relies on mask-free strain engineering techniques along with co-implanted halos and laser anneal. The impact of laser anneal on transistor reliability and mixed-signal capabilities are also examined. Drive current as high as 660/320 muA/mum at 1nA/mum and 1.1V are reported

The fully depleted (FD) SOI MOSFET is generally considered as one of the best candidates for next CMOS technology nodes. However, new technological boosters need to be introduced in the classical FD SOI process flow to reach the very aggressive Ion/Ioff specifications predicted by the ITRS roadmap. The use of a thin buried oxide (BOX) on FD SOI is still a controversial subject, despite recent publications that have demonstrated its interest for improvement of short channel effect (SCE) control, especially with a ground plane (GP) integration (Tsuchiya et al.). In order to improve the device performances, a strained "contact etch stop layer" (CESL) technique has been successfully demonstrated to induce strain into the channel of bulk devices (Thompson et al., 2002) as well as in ultra-thin FD SOI devices (Singh et al., 2005 and Gallon et al., 2006). However, its compatibility with the specific technological features of FD SOI devices, such as silicon film thickness (TS1) variations, BOX material and BOX thickness (TBOX), raised source/drain architecture, has yet to be clarified. In this paper, we demonstrate, by electrical and mechanical simulations, the interest of thin BOX with GP, combined with a strained liner. These simulations have then been validated by measurements, showing excellent Ion/Ioff pMOS performances

International audience

In this work, we report on the integration of 30nm gate length CMOS devices fabricated using laser spike annealing (LSA). Considerably improved short channel effects and drive current (+10% Ion at constant Ioff for NMOS) are demonstrated on samples using LSA. Excellent IonIoff characteristics (Ion = 940 muA/mum Ioff = 200 muA/mum for NMOS and Ion = 390muA/mum Ioff = 50 nA/mum for PMOS at Vdd = 1 V) are measured that are at the leading edge of the state of the art. Moreover, an enhanced dynamic behavior (-6% in ring oscillator delay) and improved characteristics of high density SRAM bit-cells (+24% Icell for the same 1sb) are reported. These results demonstrate the potential of LSA in the perspective of 30 nm device integration of a 45 nm bulk CMOS platform

In this paper, we present a highly-performant PMOS transistor architecture featuring a buried strained SiGe layer (stressor) underneath the Si channel and in between the epitaxially grown Si S/D regions. This stressor together with the shallow trench isolation (STI) induces pseudo-biaxial compressive stress in small devices Si channel. A completely different behaviour compared to bulk-Si devices is shown. Transistors featuring a 50nm gate length, a 1.5nm physical gate oxinitride and an active area width of 0.28/spl mu/m demonstrate drive currents up to 740/spl mu/A//spl mu/m with only 48nA//spl mu/m Ioff at a supply voltage of 1.4V. Those results, regarding the oxide thickness, are in the range of the best ever reported. Moreover, this solution provides easy co-integration possibilities between HP, GP and LP (bulk-like or SON: silicon-on-nothing) devices on the same chip.

International audience; Pseudo-MOS (Ψ -MOSFET) measurements are a simple and rapid technique for an accurate evaluation of SOI wafer intrinsic electrical properties, prior to any CMOS processing. For the first time, we report Ψ -MOSFET measurements performed on Strained SOI (SSOI) wafers with ultra-thin silicon films (9.5 nm to 17.5 nm). To take into account the wafer specificities and the use of such thin conduction layers, adapted Ψ -MOSFET models and parameter extraction methods were necessary. The experiments show an increase of the threshold and flat band voltages and a mobility reduction as the strained film becomes thinner. Further electrical analyses, coupled with several morphological studies, do not reveal any relaxation of the strain in the thinnest films. The mobility is clearly enhanced in SSOI as compared with standard SOI substrates.

A capacitor-less DRAM cell on very thin film (Tsi=16nm) and short gate length (Lg=75nm) fully depleted (FD) device is demonstrated for the first time. Memory operations mechanisms are presented and retention time compatible to eDRAM requirements is measured at 85/spl deg/C. Nondestructive reading is demonstrated at 25/spl deg/C and disturb margins are deeply investigated, showing the possibility of matrix integration. This study is then extended to another type of FD device: the very promising double gate architecture.

International audience; A wide workfunction (/spl Phi//sub m/) tuning range from 4.29eV to 4.99eV using total silicidation of doped polysilicon gate with nickel is presented. As, B and P but also N, Ge, Sb, In and co-implants, have been investigated to modulate the NiSi gate workfunction by dopant pile up effect at the silicide/dielectric interface. For the first time, defectivity data on dual gate oxide are presented, in correlation with the activation annealing impact and back end of line (BEOL) thermal stress effects as well as thorough TEM observations.

We propose to compare the main classical methods used for mobility parameters extraction (static method or split C-V) with a new approach based on magnetoresistance (MR) measurements. We focus on short channel devices behavior and compare it with long channel transistor behavior. This exhaustive study indicates that the magnetoresistance method is well adapted for thin film mobility extraction for fully-depleted SOI devices as thin as 10 nm.

We present results of simulations on silicon-on-nothing (SON) devices featuring ultra-thin Si channels. The simulations are based on QUANTIX, a 2D-Finite Element solver, and consequently fully account for quantization effects. Quantum simulations demonstrate the impact of carriers confinement in very thin Si conduction channel, therefore leading on a substantial threshold voltage increase, up to 350 mV from TSi=10 to 1 nm. Experimental data from SON devices featuring ultra-thin (

In this paper, the authors presented an integration strategy for metal gate GAA transistors made by SON process using poly-gate replacement through contact hole (PRETCH). Double gate (DG) type MOSFETs, including planar DG gate-all-around and fin-FETs are today known as the best candidates for the ultimate sealing of the logic CMOS technologies on silicon. One of the main difficulties in optimizing DG devices is the control of the threshold voltage (V/sub th/) from high performances to low power devices. With polysilicon gates, a higher channel doping has to be used when lowering the silicon thickness (T/sub Si/). This adjustment strategy has its limits and thus, gate workfunction engineering seems necessary for thin DG transistors.

To remain competitive IC manufacturers have to accelerate the development of most advanced (CMOS) technology and to deliver high yielding products with best cycle times and at a competitive pricing. With the increase of technology complexity, also the need for physical characterization support increases, however many of the existing techniques are no longer adequate to effectively support the 65–45 nm technology node developments. New and improved techniques are definitely needed to better characterize the often marginal processes, but these should not significantly impact fabrication costs or cycle time. Hence, characterization and metrology challenges in state‐of‐the‐art IC manufacturing are both of technical and economical nature. TEM microscopy is needed for high quality, high volume analytical support but several physical and practical hurdles have to be taken. The success rate of FIB‐SEM based failure analysis drops as defects often are too small to be detected and fault isolation becomes more difficult in the nano‐scale device structures. To remain effective and efficient, SEM and OBIRCH techniques have to be improved or complemented with other more effective methods. Chemical analysis of novel materials and critical interfaces requires improvements in the field of e.g. SIMS, ToF‐SIMS. Techniques that previously were only used sporadically, like EBSD and XRD, have become a ‘must’ to properly support backend process development. At the bright side, thanks to major technical advances, techniques that previously were practiced at laboratory level only now can be used effectively for at‐line fab metrology: Voltage Contrast based defectivity control, XPS based gate dielectric metrology and XRD based control of copper metallization processes are practical examples. In this paper capabilities and shortcomings of several techniques and corresponding equipment are presented with practical illustrations of use in our Crolles facilities.

International audience

Studies on psychrophilic enzymes to determine the structural features important for cold-activity have attracted increased attention in the last few years. This enhanced interest is due to the attractive properties of such proteins, i.e. a high specific activity and a low thermal stability, and thus, these enzymes constitute a tremendous potential for fundamental research and biotechnological applications. This review examines the impact of low temperatures on life, the diversity of adaptation to counteract these effects and gives an overview of the features proposed to account for low thermal stability and cold-activity, following the chronological order of the catalytic cycle phases. Moreover, we present an overview of recent techniques used in the analysis of the flexibility of a protein structure which is an important concept in cold-adaptation; an overview of biotechnological potential of psychrophilic enzymes and finally, a few frequently asked questions about cold-adaptation and their possible answers.

The very low water temperatures existing in polar oceans that experience seasonal advance and retreat of pack ice do not inhibit the presence of large bacterial populations. Bacteria may contribute significantly to the energy transfers within the Southern Ocean. In the last decades, notable progress has been made in the knowledge of the role of marine bacteria in the Southern Ocean. A short overview of the abundance and function ofAntarctic marine bacteria is given, with respect to metabolic activity. The importance of spatial and temporal variability is described. The ecological function of Antarctic marine bacterioplankton is discussed. Depending on food web structure, bacteria may be either a link in food webs supporting metazoan production, or a sink where bacterial production is metabolised by microorganisms. In the more oligotrophic areas and during certain periods of the year bacterial biomass dominates phytoplankton. The microbial food web is therefore the dominant pathway for carbon and energy flow in Antarctic seawater.

In this paper, we present electrical results on damascene CMOS devices containing a HfO/sub 2/ gate oxide and a TiN/W gate electrode and give a detailed analysis of the performance data and the carrier mobility in both pMOS and nMOS devices. We report on an improvement of the electron mobility compared to recent literature data, which seems to be related to a slightly higher interfacial oxide layer. These findings are very interesting regarding the definition of a good trade-off between mobility and EOT for future CMOS transistors using high-k materials for the gate oxide.

We present in this paper a detailed analysis of the electrical behaviour of NMOS transistors with gate lengths down to Lg = 30 nm where the source/drain extensions (SDE) were developed using ultra low energy implantation (As 1 keV) or plasma doping (PLAD) at low bias (1.5 kV). PLAD splits show excellent threshold characteristics in comparison with As 1 keV: delayed Vt roll-down, reduced short channel effect (SCE) and drain induced barrier lowering (DIBL). The Ion/Ioff trade-off analysis reveals a much lower Ioff for comparable gate lengths when using PLAD instead of ULE. These behaviours are explained by a reduced junction depth Xj, which is confirmed by a parameter extraction on transistor characteristics and by analytical modelling.

IEEE International Electron Devices Meeting, WASHINGTON, D.C., DEC 08-10, 2003; International audience; Utilizing the SON (Silicon On Nothing) process, highly performant double gate devices have been processed in a planar configuration. Two families of devices were obtained (High Performance and Low Power) with very-high Ion/Ioff trade off. Drive currents of 1954muA/mum (Ioff = 283 nA/mum) and 1333 muA/mum (Ioff = 1 nA/mum) are obtained @1.2V with Tox = 20A and Lgate = 70nm. DIBL is very well controlled, measured below 60mV for gates as short as 40nm. These features place our devices among the most performant ever reported.

50th IEEE International Electron Devices Meeting, San Francisco, CA, DEC 13-15, 2004; International audience; We report on a new concept for an easy co-integration, on a same chip, of different MOSFET configurations (GP, LP, HS, buffer transistors) realized after the end of the standard FE process. This Poly-gate Replacement Through Contact Hole PRETCH) concept enables replacement of initial poly-silicon gate and/or gate oxide by any gate stack desired. PRETCH addresses multi-Vt control, multi-oxide realization and metal gate integration challenges. As PRETCH gate replacement takes place after PMD (beginning of BE), it is perfectly suitable for High-K integration, allowing low thermal budget (no source and drain anneal seen by HK) and no particular contamination issues. Large potential of PRETCH integration is confirmed by promising morphological results and by very good electrical characteristics of both nMOS and pMOS TiN 90nm gate length MOSFETs. Integration of TiN gate with three different oxide configurations is demonstrated: initial thermal oxide left, replaced by either Slot Plane Antenna [SPA] oxide or High-K. PRETCH concept has also been validated on 3D architectures such as DG. Finally, functional TiN DG inverters and SRAMs are demonstrated.

Untreated sewage has been released from Port-aux Francais station, Kerguelen Island, into the Southern Ocean for more than 50 years. We investigated the spatial distribution of faecal bacteria indicators during a one-year survey conducted in seawater off Morbihan Bay near the French permanent station of the Kerguelen Island (4921 0 S, 7030 0 E). Seawater samples were taken bimonthly from nine stations evenly distributed around the sewage outfalls of the station. Escherichia coli and enterococci were estimated using specific microplates (Miniaturized method for the enumeration of E. coli or enterococci in surface and waste waters, ‘‘MU/EC or MU/SF methods’’, BIO-RAD). In order to evaluate the role of seasonal changes of environmental parameters on the survival of enteric bacteria, total and saprophytic bacterial abundances were also estimated in all seawater samples. High densities of faecal bacteria (maximum 10 4 cells 100 ml � 1 ) were found in seawater surrounding the sewage outfall. However, enteric bacterial counts decreased rapidly with increasing distance from the outfall. In all samples collected further than 2 km from the outfall, the bacterial indicators were absent or present in small numbers (

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

Oil pollution of the oceans has been a problem ever since man began to use fossil fuels. Biodegradation by naturally occurring populations of micro-organisms is a major mechanism for the removal of petroleum from the environment. To examine the effects of crude oil pollution on intertidal bacteria, we repeated the same contamination experiments on nine different sub-Antarctic intertidal beaches using specifically built enclosures (PVC pipe, 15 cm in inner diameter and 30 cm in height). Despite the pristine environmental conditions, significant numbers of indigenous hydrocarbon-degrading bacteria were observed in all the studied beaches. Introduction of oil into these previously oil-free environments resulted in several orders of magnitude of increase in hydrocarbon-degrading micro-organisms within a few days in some of the studied sites but has no obvious effects on two others. The physical environment of the bacterial assemblage seems to play a major role in the biodegradation capacities. After 3 months of contamination, both remaining oil concentrations and biodegradation indexes differ strongly between the different stations. Thus, chemical and biological parameters reveal a strong heterogeneity of biodegradation capacities between the different sites.

In the last few years, increased attention has been focused on enzymes produced by cold-adapted micro-organisms. It has emerged that psychrophilic enzymes represent an extremely powerful tool in both protein folding investigations and for biotechnological purposes. Such enzymes are characterised by an increased thermosensitivity and, most of them, by a higher catalytic efficiency at low and moderate temperatures, when compared to their mesophilic counterparts. The high thermosensitivity probably originates from an increased flexibility of either a selected area of the molecular edifice or the overall protein structure, providing enhanced abilities to undergo conformational changes during catalysis at low temperatures. Structure modelling and recent crystallographic data have allowed to elucidate the structural parameters that could be involved in this higher resilience. It was demonstrated that each psychrophilic enzyme adopts its own adaptive strategy. It appears, moreover, that there is a continuum in the strategy of protein adaptation to temperature, as the previously mentioned structural parameters are implicated in the stability of thermophilic proteins. Additional 3D crystal structures, site-directed and random mutagenesis experiments should now be undertaken to further investigate the stability-flexibility-activity relationship.

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008

During a 1-year period, systematic observations of the Antarctic coastal marine bacterioplankton were recorded. Three field stations were sampled weekly in 1989 in “Terre Adelie” area. The survey included physicochemical (temperature and particulate organic matter) and bacteriological (total and heterotrophic counts, estimation of bacterial production) measurements. The bacterial community structure was investigated by carrying out 27 morphological and biochemical tests on 254 strains isolated during each season. Gram-negative non-fermentative rods were always dominant. However, an obvious difference exists between the communities inhabiting ice-free and ice-covered seawater. The potential metabolic abilities which were relatively significant in the summer community were severely reduced in the winter community. A general increase in bacterial biomass and production was observed in surface water after sea ice formation. The results suggest a close coupling between heterotrophic bacterioplankton and the input of allochthonous organic carbon, for example from the overlying sea-ice communities or from nearby penguin rookeries.

In this communication we present a method using Focused Ion Beam (FIB), Energy Filtered TEM (EFTEM) and STEM for semiconductor defects interception and high resolution observation. This method takes benefit of the specific imaging properties of respectively EFTEM and STEM techniques. A demonstration is presented for the observation of dislocations in a silicon integrated circuit.Silicon defects such as dislocations are one of the major issues in Integrated Circuit fabrication. Due to their low distribution density these silicon defects are not easily observed using TEM cross section. in this paper we present a more appropriate technique using: FIB, EFTEM and STEM for such defects observation. First, in order to improve the probability of defects being present in the specimen, a very thick lamella is prepared using FIB. Then, using an energy filter for eliminating the inelastic electrons needed to allow thick specimen TEM imaging, direct defect localization and observation at medium resolution is carried out. After that, taking advantage of the beam broadening in the STEM, the defect position inside the specimen is more accurately evaluated. For that purpose two STEM observations are carried out from the two opposite specimen surfaces. The comparison of image contrast is used for further FIB specimen thinning. The process can be continued down to a thickness compatible with an acceptable spatial resolution TEM imaging.