Le travail porte sur le développement et l’optimisation de transistors bipolaires à hétérojonction (TBH) SiGe et SiGeC par conception technologique assistée par ordinateur (TCAD). L'objectif est d'aboutir à un dispositif performant réalisable technologiquement, en tenant compte de tous les paramètres : étapes de fabrication technologiques, topologie du transistor, modèles physiques. Les études menées permettent d’atteindre les meilleures performances, en particulier une amélioration importante de la fréquence maximale d’oscillation (fMAX). Ce travail est la première approche développée pour la simulation des TBH SiGeC qui prend en compte l'impact de la contrainte et de la teneur en germanium et en carbone dans la base; conjointement pour les simulations des procédés de fabrication et les simulations électriques.Pour ce travail, nous avons développé et implémenté dans le simulateur TCAD des méthodes d'extraction de fMAX prenant en compte les éléments parasites intrinsèques et extrinsèques. Nous avons développé et implémenté un modèle pour la densité effective d’états fonction de la teneur en germanium et en carbone dans la base. Les modèles pour la bande interdite, la mobilité et le temps de relaxation de l'énergie sont calibrés sur la base de simulations Monte-Carlo.Les différentes analyses présentées dans cette thèse portent sur six variantes technologiques de TBH. Trois nouvelles architectures de TBH SiGeC avancés ont été élaborées et proposées pour des besoins basse et haute performance. Grace aux résultats obtenus, le meilleur compromis entre les différents paramètres technologiques et dimensionnels permettent de fabriquer un TBH SiGeC avec une valeur de fMAX de 500 GHz, réalisant ainsi l’objectif principal de la thèse. / The present work investigates the technology development of state-of-the-art SiGe and SiGeC Heterojunction Bipolar Transistors (HBT) by means of technology computer aided design (TCAD). The objective of this work is to obtain an advanced HBT very close to the real device not only in its process fabrication steps, but also in its physical behavior, geometric architecture, and electrical results. This investigation may lead to achieve the best electrical performances for the devices studied, in particular a maximum operating frequency of 500 GHz. The results of this work should help to obtain more physical and realistic simulations, a better understanding of charge transport, and to facilitate the development and optimization of SiGe and SiGeC HBT devices.The TCAD simulation kits for SiGe/SiGeC HBTs developed during our work have been carried out in the framework of the STMicroelectronics bipolar technology evolution. In order to achieve accurate simulations we have used, developed, calibrated and implemented adequate process models, physical models and extraction methodologies. To our knowledge, this work is the first approach developed for SiGe/SiGeC HBTs which takes into account the impact of the strain, and of the germanium and carbon content in the base, for both: process and electrical simulations.In this work we will work with the successive evolutions of B3T, B4T and B5T technologies. For each new device fMAX improves of 100 GHz, thus the technology B3T matches to 300 GHz, B4T and B5T to 400 and 500 GHz, respectively.Chapter one introduces the SiGe SiGeC heterojunction bipolar technologies and their operating principles. This chapter deals also with the high frequency AC transistor operation, the extraction methods for fMAX and the carrier transport in extremely scaled HBTs.Chapter two analyzes the physical models adapted to SiGeC strained alloys used in this work and the electrical simulation of HBT devices. This is also an important work of synthesis leading to the selection, implementation and development of dedicated models for SiGeC HBT simulation.Chapter three describes the B3T TCAD simulation platform developed to obtain an advanced HBT very close to the real device. In this chapter the process fabrication of the B3T technology is described together with the methodology developed to simulate advanced HBT SiGeC devices by means of realistic TCAD simulations.Chapter four describes the HBT architectures developed during this work. We will propose low-cost structures with less demanding performance requirements and highly performing structures but with a higher cost of production. The B4T architecture which has been manufactured in clean-room is deeply studied in this chapter. The impact of the main fabrication steps is analyzed in order to find the keys process parameters to increase fMAX without degrading other important electrical characteristics. At the end of this chapter the results obtained is used to elaborate a TCAD simulation platform taking into account the best trade-off of the different key process parameters to obtain a SiGeC HBT working at 500 GHz of fMAX.

Dans le cadre des procédés de clarification d'eau de surface, les flocs formés au cours des étapes de coagulation et de floculation peuvent être séparés de l'eau traitée par décantation ou par flottation. Dans ce dernier cas, le procédé actuellement en vigueur est la flottation à air dissous et présente un certain nombre d'inconvénients. Ainsi, dans ce contexte, la présente thèse consiste à développer un matériau innovant, à la fois flottant et floculant, pour une application dans un procédé de flottation sans air. Dans un premier temps, l'élaboration de billes de polystyrène expansibles utilisant l'eau ou l'éthanol comme agent gonflant a été réalisée. D'autres billes ont ensuite été préparées en présence de 4-(chlorométhyl)styrène comme co-monomère puis la polymérisation par transfert d'atome amorcée en surface (SI-ATRP) de l'acrylamide a été effectuée avec succès. L'impossibilité d'expanser ces matériaux a ensuite conduit à l'exploration de nouvelles voies de synthèse avec la fonctionnalisation de matériaux flottants existants par des techniques de « grafting from » ou « grafting onto ». Quelle que soit la voie envisagée, la première étape a consisté à réduire les fonctions nitrile en amine primaire en présence d'hydrure d'aluminium lithium. Après fonctionnalisation par du bromure de bromoisobutyryle ou du chlorure d'acryloyle, il a été possible de venir greffer de l'acrylamide par SI-ATRP ou de l'amidon via un amorceur redox, respectivement. Les matériaux flottants/floculants obtenus ont été testés lors de flottatests. Les meilleurs résultats ont été obtenus avec les microsphères fonctionnalisées par de l'amidon anionique. Ces dernières ont permis d'abattre la turbidité de l'eau, ont ensuite été régénérées avec succès, par des bains d'acide oxalique ou de dithionite de sodium, et employées durant plusieurs cycles flottatest/régénération avec des résultats reproductibles. / At the end of clarification process, after coagulation-flocculation steps, flocs can be removed from treated water by settling or flotation. In the latter case, Dissolved Air Flotation is the currently used process. However, this method showed important drawbacks, especially an important energetic cost due to the production of air saturated water. In that context, the goal of the reported work dealt with achieving air-free flotation using innovative floating materials. First of all, the synthesis of expandable polystyrene beads using water or ethanol as blowing agent was investigated. Other beads containing both styrene and 4-(chloromethyl)styrene were prepared. Then, surface initiated atom transfer radical polymerization of acrylamide (SI-ATRP) was achieved. Unfortunately, the expansion of such materials was not possible. Therefore, the second part focused on the functionalization of Expancel beads by “grafting from” or “grafting onto” techniques. The first step consisted in reducing some nitrile functions at the surface into primary amine ones. After functionalization with bromoisobutyryl bromide, the SI-ATRP of acrylamide was performed in water at room temperature. On the other hand, the acryloyl chloride was grafted onto amine functions, and grafting of starch was achieved using a redox initiator. All materials obtained have been used for flocculation/flotation tests and demonstrated satisfactory performances in terms of turbidity removal. Beads functionalized with starch have been successfully regenerated with oxalic acid and sodium dithionite and kept appropriate efficiency during several flotation/regeneration cycles.

Les travaux de recherche menés dans cette thèse s’inscrivent dans le cadre de la réalisation de la technologie cellule solaire intégrée (i-Cell), qui est une technologie innovante de fabrication de cellules solaires à hauts rendements de conversion et à bas coût de production. L’i-Cell consiste en la réalisation de plusieurs cellules élémentaires ou sous-cellules, en feuilles minces de silicium cristallin purifié, qui sont connectées en série sur un substrat de Si fritté bas coût. La technologie i-Cell permet en effet la réduction du coût de la plaquette grâce à la faible épaisseur des feuilles de silicium et grâce à l’utilisation de substrats issus du frittage de poudres de silicium. Dans une telle structure la fonction photovoltaïque est assurée par la feuille mince de surface alors que le transport du courant et la fonction mécanique sont gérés par le substrat fritté ce quipermet de réduire les coûts de fabrication de la cellule. En effet, à l’instar des couches minces, on peut décomposer la couche active en cellules de faibles surfaces et ainsi produire sur une surface standard (156 x 156 mm²), une cellule dans laquelle circule un faible courant qui permet de réduire fortement la consommation des métaux précieux au sein de la cellule (Argent) et entre les cellules du module (Cuivre). En outre, la configuration des cellules à i-Cell permet de s’affranchir des busbars en Ag traditionnellement utilisés dans les technologies silicium. Ceci présente l’avantage d’éviter le masquage de la lumière et donc d'augmenter la puissance de la cellule. Ce travail de thèse s’articule sur deux axes de recherche principaux. Le premier est orienté sur l’étude de la cinétique d’oxydation thermique de substrats de silicium frittés poreux. Le deuxième axe concerne la réalisation du substrat fritté intégré et la réalisation des premiers prototypes d’i-Cells sur ces derniers. Ce travail a permis de démontrer la faisabilité de l’i-Cell et de réaliser des prototypes d’i-Cell sur le substrat fritté intégré. Des rendements de conversion PV supérieurs à 18% ont été ainsi obtenus. / The research work conducted in this thesis are within the framework of the realization of the integrated solar cell technology (i-Cell), which is an innovative solar cell technology with a high conversion efficiency and a low cost production. The i-Cell consists of the realization of several elementary cells or sub-cells, in purified crystalline silicon thin foils, which are connected in series on a low cost sintered silicon substrate. In fact, the i-Cell technology allows the reduction of the cost of the wafer thanks to the low thickness of the silicon foils and through the use of substrates obtained from the sintering silicon powders. In such a structure, the photovoltaic function is provided by the thin purified Si foil on the surface. Whereas both the current transport and the mechanical function are provided by the sintered silicon substrate – thin allows to reduce the cell manufacturing costs. In fact, just like thin films, we can decompose the active layer in small cell surfaces and thus produce, on a standard surface (156 x 156 mm²), a low current cell that greatly reduces the consumption of precious metals within the cell (Silver) and between the cells within the module (Copper). Furthermore, the configuration of cells in the i-Cell technology permits to eliminate the use of Silver busbars traditionally used in the Si solar cell technologies. This offers the advantage of avoiding the masking light and thus increases the power of the i-Cell. This thesis work focuses on two main axes of research: The first axis relates to the study of the kinetics of thermal oxidation of porous sintered silicon substrates. The second axis of research focuses on the realization of the “integrated sintered substrates”, which consists of the realization of local conductive zones on the insulating porous sintered substrate, and the fabrication of the first i-Cells prototypes on them. This work demonstrated the feasibility of i-Cell and produced prototypes of i-Cell on the integrated sintered substrate. High photovoltaic conversion efficiencies, greater than 18%, were obtained.

Este trabalho tem como objetivo o estudo da influência do boro na fase αNb5Si3 (Fase T2) a baixas temperaturas analisando suas propriedades elétricas e magnéticas. Para o estudo deste tema as amostras foram preparadas, seguindo a estequiometria Nb5Si3-xBx, via metalurgia do pó e também por fusão a arco, com x dentro do intervalo limitado por 0  X  1,0. Estas amostras foram analisadas através de difratometria de raios x, microscopia eletrônica de varredura, magnetização, transporte elétrico e medidas calorimétricas em baixa temperatura. As medidas das propriedades elétricas e magnéticas destas fases mostram que a substituição de boro por silício induz supercondutividade na fase T2. O caráter volumétrico da transição supercondutora é confirmado pela medida de capacidade calorífica. Assim, este trabalho é o primeiro a mostrar uma nova família de materiais supercondutores que cristalizam na estrutura protótipo Cr5B3. / This work to study the influence of boron during low temperature αNb5Si3 (T2 phase) analyzing their electrical and magnetic properties. For the study of this subject the samples were prepared, following the stoichiometry Nb5Si3-xBx via powder metallurgy and also by arc melting process, with x within the range limited by 0X1.0. These samples were analyzed by X-ray diffraction, scanning electron microscopy, magnetization, electrical transport and calorimetric measurements of low temperature. Measurements of electrical and magnetic properties of these phases show that the substitution of boron by silicon induces superconductivity at the T2 phase. The bulk nature of superconducting transition is confirmed by heat capacity measurement. This study is the first to show a new family of superconducting materials that crystallize in the Cr5B3 prototype structure.

Whist copper (Cu) is an essential element for plants, when this element is present in excess quantities it can cause irreversible damage. This metal induces excessive production of reactive oxygen species (ROS), which damages organelles causing dysfunction. A possible means for the promotion of metal tolerance in plants is the adition of the element silicon (Si). The current study was conducted with the aim of evaluating the role of Si (0, 1 and 3 mmol L-1) on the morphologic, nutritional, metabolic and physiological responses of Panicum maximum cv. Tanzania under different Cu rates (0.3, 250, 500 and 750 μmol L-1). The grass was grown in a greenhouse under hydroponic conditions for two growth periods (33 and 30 days). Thirteen days after sowing, the seedlings were transplanted to a nutrient solution and supplied just with the Cu rate of 0.3 μmol L-1 and the set Si rates for 25 days. The remaining Cu rates were only added for a seven day period during the first growth stage. The second harvest took place 31 days after the first harvest. The experiment had six randomized blocks: three for yield, morphology and nutritional analyses and three for metabolic and physiological analyses. Plant yield, morphology and metabolic parameters were quantified in shoots and roots. Chlorophyll content index (SPAD values) and gas exchange parameters were determined in diagnostic leaves (DL), and Cu and Si concentrations were analysed from the DL and roots. The calculation of Cu and Si contents took into account the whole plant biomass. Plants exposed to Cu rates above 0.3 μmol L-1 showed low values of plant yield, morphologic parameters and SPAD, in both growth periods. Silicon supplied plants showed lower Cu concentration and content, and higher values of plant yield, morphlogic parameters and SPAD than the ones with no Si application. Silicon concentration and content were higher in plants exposed to excess Cu compared to those exposed to the control rate (0.3 μmol L-1). Gas exchange parameters in plants of the first growth were positively affected by Si supply and negatively affected by Cu rates. In the second growth, an eustress event was observed, in which plants exposed to stressing rates of residual Cu showed the highest values of gas exchange parameters and the lowest values of stress indicators. The activities of antioxidant enzymes were reduced with the increment in Cu rates. Silicon supply resulted in an increment in superoxide dismutase (SOD) activity. Tanzania guinea grass supplied with Si was able to better deal with Cu toxicity, showing increases in plant yield, morphologic and gas exchange parameters. Silicon supplied plants reduced their absorption of Cu and consequently, plants exposed to high Cu rates were still able to produce considerable biomass in the regrowth. / O cobre (Cu) é um elemento essencial para as plantas, porém, quando em excesso, pode causar danos irreversíveis às plantas. Este metal induz a produção excessiva de espécies reativas de oxigênio (ERO), que danificam organelas causando a disfunção delas. Uma possível maneira de aumentar a tolerância de plantas aos metais é o fornecimento de silício (Si). Um experimento foi conduzido com o objetivo de avaliar o papel do Si (0, 1 e 3 mmol L-1) nas respostas morfológicas, nutricionais, metabólicas e fisiológicas do Panicum maximum cv. Tanzânia sob doses de Cu (0,3, 250, 500 e 750 μmol L-1). Esse capim foi cultivado hidroponicamente em casa de vegetação por dois períodos de crescimento (33 e 30 dias). Treze dias após a semeadura, plântulas foram transplantadas para solução nutritiva, fornecendo-se apenas as doses de Si por 25 dias. A exposição ao cobre foi realizada apenas no primeiro crescimento das plantas e durou sete dias. O segundo corte ocorreu 31 dias após o primeiro corte. O experimento consistia de seis blocos completos ao acaso: três para avaliações de produção, morfologia e análises nutricionais e três para análises metabólicas e fisiológicas. A produção, a morfologia e o metabolismo das plantas foram quantificados na parte aérea e nas raízes. O índice de conteúdo de clorofila (valores SPAD) e as análises fisiológicas foram determinados nas lâminas diagnósticas (LD), e as concentrações de Cu e Si nas LD e nas raízes. Para o cálculo dos acúmulos de Cu e Si levou-se em consideração toda a biomassa da planta. Plantas expostas a doses de Cu acima de 0,3 μmol L-1 apresentaram menores valores de produtividade, parâmetros morfológicos e de SPAD. Plantas supridas com Si apresentaram menor concentração e acúmulo de Cu, e maiores valores de produtividade, parâmetros morfológicos e SPAD do que aquelas que não receberam o fornecimento de Si. A concentração e o acúmulo de silício foram maiores nas plantas expostas ao excesso de Cu do que nas expostas à dose controle de Cu (0,3 μmol L-1). Os parâmetros de trocas gasosas das plantas no primeiro crescimento foram afetados positivamente pelo Si e negativamente pelo incremento nas doses de Cu. No segundo crescimento, observou-se evento de eustresse em que plantas expostas à dose de Cu residual apresentaram os valores mais altos de parâmetros de troca gasosa e os valores mais baixos de indicadores de estresse. As atividades de enzimas antioxidantes foram reduzidas com o incremento nas doses de Cu. O suprimento de silício resultou em incremento na atividade da superóxido dismutase (SOD). O capim tanzânia suplementado com Si foi capaz de suportar melhor a toxicidade do Cu, mostrando um aumento na produção de biomassa da planta, e em parâmetros morfológicos e de trocas gasosas. As plantas suplementadas com Si reduziram a absorção de Cu e, consequentemente, plantas expostas a altas taxas de Cu e suplementadas com Si ainda foram capazes de produzir uma biomassa apreciável na rebrota.

La distillation fractionnée des coupes pétrolières brutes se révèle insuffisante, pour répondre seule aux besoins en carburants et génère de fortes quantités de distillats à longue chaîne carbonée (C20-C50). Cette coupe d’hydrocarbures peu valorisable est ainsi transformée en molécules hydrocarbonées plus légères, par le biais de deux procédés : le craquage catalytique en lit fluidisé ou l’hydrocraquage. Ce dernier permet le craquage sélectif des hydrocarbures essentiellement en gazole et kérosène. Les catalyseurs acides utilisés sont « bifonctionnels » : une matrice zéolithique USY (zéolithe Y ultra-stabilisée) favorise le craquage des hydrocarbures, pendant qu’un sulfure mixte ou un métal noble greffé catalyse les réactions d’hydrogénation et de déshydrogénation. L’objectif de ce travail de thèse consiste à maximiser la sélectivité en distillats moyens, en diminuant le temps de séjour des molécules d’hydrocarbures dans la structure zéolithique, afin de réduire les réactions de surcraquage. Pour cela, il a été choisi de synthétiser directement des nanocristaux de zéolithe Y sans agent organique structurant, avec un rapport Si/Al le plus élevé possible. Cette propriété leur confère une meilleure stabilité lors des post-traitements, indispensables pour atteindre le rapport Si/Al des zéolithes USY actuellement utilisées. Grâce à l’élaboration d’une nouvelle stratégie de synthèse, des nanocristaux compris entre 20 et 90 nm avec un rapport Si/Al variant de 2,2 à 2,6 ont été obtenus. Puis, l’obtention de la forme protonée de ces nanocristaux (90 nm) a été étudiée et des mesures d’acidité ont également été effectuées. / The fractionated distillation of crude oil is not sufficient to cover all the fuel needs and produces large amounts of long chain carbon distillates (C20-C50). Thus, these hydrocarbons are transformed into lighter hydrocarbon molecules by two processes: fluid catalytic cracking or hydrocracking. The latter allows the selective cracking of hydrocarbons essentially in gas oil and kerosene. The acid catalysts used are “bifunctional”: a zeolite matrix USY (ultra-stabilized zeolite Y) performs the hydrocarbons cracking, at the same time a sulfide or a noble metal catalyzes hydrogenation and dehydrogenation reactions. The aim of this work is to maximize the selectivity to middle distillates by decreasing the residence time of hydrocarbon molecules in the zeolite framework. For this, it was chosen to directly synthesize zeolite Y nanocrystals with the highest possible Si/Al ratio, in a SDA-free medium. This property gives them a better stability during the post-treatments essential to reach the Si/Al ratio of the currently used USY zeolite. Thanks to a new synthesis strategy, nanocrystals between 20 and 90 nm with a Si/Al ratio varying from 2.2 to 2.6 were obtained. Then, the protonated form of these nanocrystals (90 nm) was studied and acidity measurements were also carried out.

This dissertation examined the extent to which interests and values of diverse stakeholders were considered through participation-oriented decision-making. It covered the An' Yang Stream restoration case in South Korea, which has been judged a successful stream management endeavor led by public-private partnership governance. This research utilized a mixed methods approach, combining qualitative and quantitative methods. It addressed the extent to which the collaborative and participatory decision-making processes incorporated diverse stakeholder values and visions. The relevant data on stream restoration was collected through nominal group technique (NGT), analytic hierarchy process (AHP), semi-structured interviews, observations at collaborative stakeholder meetings and workshops, and documentation review. My research concluded that integration of all interests was not achieved. These interests might have potentially affected the extent to which stakeholders' values are incorporated or not in participation-oriented collaborative stakeholders' partnerships by utilizing interest-based facilitation techniques, such as joint-fact-finding or principled negotiation. At the same time, my findings expatiate the catalyzing roles of the public media within stream restoration decision-making governance.

O aço SAE AISI 52100 com microestrutura martensítica revenida é utilizado para a fabricação de rolamentos como também na fabricação de outras peças e dispositivos para aplicações marinhas. A modificação deste aço com a adição de silício e manganês pode melhorar as propriedades mecânicas em média-alta temperatura. Este aço modificado ao Si e Mn apresenta grande resistência ao amolecimento durante o revenimento, o que pode ser explorado quanto ao comportamento em altas temperaturas. Para a realização deste trabalho, foi utilizado o aço AISI 52100 com composição química conforme estabelece a norma ASTM A295- 2014, e um aço experimental com 1,82% de Si e 1% de Mn baseado no aço AISI 52100. Após tratamento térmico de normalização, investigou-se os fenômenos de transformação de fase por meio de estudos microestruturais, mecânicos e corrosivos em diferentes temperaturas. A adição de Si e Mn junto ao tratamento de normalização conferiram melhor dureza, tenacidade ao impacto e maior resistência à tração a 25, 300 e 400 oC, porém diminuiu a resistência à corrosão comparada à do aço AISI 52100 na condição utilizada nas indústrias. Portanto, o aço modificado normalizado se mostrou adequado para utilização em maiores temperaturas que não exijam resistência à corrosão em solução de NaCl 3,5 %p. / SAE AISI 52100 steel with tempered martensitic microstructure is used for the manufacture of bearings as well as in the manufacture of other parts and devices for marine applications. The modification of this steel with the addition of silicon and manganese can improve the mechanical properties in medium-high temperature. This Si-Mn modified steel exhibits high resistance to softening during tempering, which can be exploited in high temperature behavior. For this work, it was used the AISI 52100 steel with chemical composition in accordance to ASTM A295- 2014 and an experimental steel with 1.82% Si and 1% Mn, based on AISI steel 52100. After normalization heat treatment, the phenomena of phase transformation were investigated through microstructural, mechanical and corrosive studies at different temperatures. The addition of Si and Mn together with the normalization treatment improve hardness, impact toughness and tensile strength at 25, 300 and 400 oC, but decreased the corrosion resistance compared to AISI 52100 steel in the condition used in the industries. Therefore, normalized modified steel proved to be suitable for use at higher temperatures that do not require corrosion resistance in 3.5%w. NaCl solution.

Ce travail a pour but de comprendre l’effet de la compensation du dopage sur les performances des cellules photovoltaïques à base de silicium de qualité solaire purifié par voie métallurgique. Après avoir développé la physique des matériaux compensés, l’influence de la compensation a été étudiée à l’échelle de la plaquette. Nous avons mis en évidence une forte réduction non prédite de la mobilité des porteurs. Au contraire, la compensation du dopage s’est avérée bénéfique à la durée de vie volumique. Nous avons précisé les propriétés recombinantes des dopants. L’étude a été transposée à l’échelle de la cellule. Des rendements de 16% ont été obtenus sur des cellules fortement dopées et compensées. La présence de nombreuses associations entre impuretés dopantes et défauts nous a conduits à l’élaboration d’un algorithme permettant de simuler la cinétique de ce type d’association. Enfin, deux techniques innovantes de mesure des teneurs en dopants et en oxygène interstitiel ont été présentées. / This study aims at understanding the influence of the dopant compensation on the performances of solar cells based on solar-grade silicon purified via metallurgical routes. We first detailed the physics of compensated semiconductors. The compensation effects were then studied at the wafer level. We found a sharp unpredicted reduction in carrier mobility at high compensation level. Conversely, the dopant compensation was shown to be very beneficial to the carrier lifetime. We specified the recombination properties of dopants. We then focused on the compensation effects at the solar cell level. We obtained conversion efficiencies of 16% on highly doped and compensated solar cells, revealing the photovoltaic potential of solar-grade silicon. Since numerous association reactions occur between dopants and defects, we built an algorithm in order to simulate the association kinetics of such reactions. Eventually, we presented two innovative characterisation techniques that allow the concentrations of dopants and light elements to be measured.

L'objectif de cette étude est de regarder l'influence du Pt sur la formation des siliciures de Ni dans le procédé Salicide et en particulier sur la phase basse résistivité NiSi, envisagée par l'industrie pour réaliser les contacts avec les zones actives de transistors de type Flash. Pour cela, nous avons étudié la nature, la séquence et la cinétique des phases formées, d'une part sur le système Ni1-xPtx/Si(100) (0% ≤ x ≤ 30%), et plus particulièrement sur un système intéressant pour certaines de ces propriétés, Ni(13%Pt)/Si(100). Deux types de dépôts ont été confrontés : dépôts réalisés avec une cible alliée Ni(13%Pt) ou par codéposition (cibles Ni et Pt dissociées). Ainsi nous avons couplé différentes techniques de caractérisation in situ (diffraction des rayons X, Réflectivité des rayons X (RRX), résistivité 4 pointes) pour essayer de comprendre les mécanismes liés à ce système. En particulier des expériences de RRX in-situ, associées à une analyse par transformée de Fourier inverse, ont été mises en œuvre, en utilisant le rayonnement synchrotron (ESRF), et aboutissent à des résultats originaux : la séquence des phases est modifiée dans le cas du Ni(13%Pt). Enfin, des premières mesures de résistance sur lignes étroites ont été réalisées, soulignant les avantages et les limites associées à l'utilisation d'un tel système.