Le graphène est un plan unique d'atomes de carbone formant une structure en nid d'abeilles. Dans le cas idéal, le graphène possède des propriétés physiques étonnantes résultant de sa structure électronique en « cône de Dirac ». En particulier, la mobilité électronique dans le graphène est exceptionnelle ce qui ouvre des perspectives pour les transistors futurs. Dans cette thèse notre objectif est de tester les propriétés et les performances de transistors réalisés sur graphène à l'aide d'une technologie compatible CMOS. Depuis 2004, il est connu qu'on peut obtenir ce matériau bidimensionnel à partir de la graphitisation du carbure de silicium (SiC). C'est cette technique qui a été utilisée ici. Parmi les résultats obtenus, nous présenterons en particulier une méthode innovante pour déterminer le nombre de couches de graphène. Nous détaillerons la technologie d'intégration mise au point, avec la réalisation de transistors à canal court et étroit. Nous montrerons les caractéristiques obtenues. La mobilité électronique mesurée est à l’état de l’art international. Nous analyserons également le rôle du diélectrique de grille sur la qualité des performances. / Graphene consists of a single atoms plane reorganized in honeycomb lattice. Ideal graphene has astonishing properties coming from his electronic structure in Dirac cone. One of these properties is an exceptional mobility indispensable for future transistors. In this work, our objective is to evaluate properties and performance of transistors based on graphene. These transistors are fabricated by using a CMOS-like integration. Since 2004, graphene can be obtained via sublimation of silicon carbide substrate. We used this technique to study graphene. We will present a particular method to enumerate the number of layer obtained in surface and the integration choosen to obtain short and thin transistors. We will show electrical characteristic obtained. The charge carrier mobility measured is similar to the state of the art. An analysis of the gate dielectric is also presented.

Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / Esforços constantes de pesquisa têm sido conduzidos na seleção de materiais, combinando propriedades de interesse (mecânicas, químicas, elétricas ou térmicas), versatilidade de uso, tempo de vida útil elevado e baixo custo de produção. A busca por materiais de elevado desempenho mecânico despertou grande interesse na pesquisa e desenvolvimento dos cerâmicos avançados com aplicações estruturais e funcionais, como o carbeto de silício. Entretanto, a porosidade ainda é vista como fator limitador do alto desempenho destes materiais visto que, acima de determinada porcentagem, reduz largamente sua resistência mecânica. Seu controle atualmente é realizado através de técnicas de alto custo, com a utilização de tomógrafos. Este trabalho buscou validar uma nova técnica, onde a porosidade foi avaliada através de processamento digital de imagens de microscopia ótica do material previamente lixado e polido em diversas profundidades, com controle dos parâmetros de lixamento e polimento. Esta nova metodologia mostrou-se apropriada e menos dispendiosa para a quantificação da porosidade do carbeto de silício, tendo sido validada para o estudo deste material. / Constant research efforts have been conducted in material selection, matching the properties of interest (mechanical, electrical, chemical and thermal), versatility of use, high lifetime and low cost of production. The search for materials with high mechanical performance aroused great interest in the research and development of advanced ceramic with structural and functional applications such as silicon carbide. However, the porosity is still seen as a limiting factor in high performance materials because, above a certain percentage, greatly reduces its mechanical strength. His control is currently performed using techniques of high cost, with the use of scanners. This study aimed to validate a new technique, where the porosity was evaluated by digital image processing of the optical microscopy in the material previously sanded and polished at various depths, with control of the material parameters. This new methodology was appropriate and less expensive to quantify the porosity of the silicon carbide and has been validated for the study of this material.

O carbeto de silício (SiC) apresenta várias propriedades extremamente interessantes para a fabricação de dispositivos eletrônicos submetidos a condições extremas como alta temperatura (300 a 600 °C), alta frequência e alta potência. Além disso, é o único semicondutor composto que, reagindo com o oxigênio, forma um óxido isolante estável, o SiO2. No entanto, as propriedades elétricas de estruturas de SiO2/SiC são degradadas pela alta concentração de estados eletricamente ativos na interface dielétrico/semicondutor. Tal característica representa uma barreira para a fabricação de dispositivos baseados nesse material. Nesta tese foram comparadas e analisadas as propriedades de estruturas SiO2/4H-SiC obtidas por diferentes processos de oxidação térmica. As estruturas resultantes foram caracterizadas por medidas de corrente-tensão, capacitância-tensão e condutância ac de alta frequência, espectroscopia de fotoelétrons induzidos por raios-X, análise por reação nuclear e microscopia de força atômica. O uso dessas técnicas analíticas visou a correlacionar o comportamento elétrico das estruturas obtidas com suas propriedades físico-químicas como, por exemplo, composição e estrutura química do óxido formado. Os resultados evidenciam diferenças específicas entre os ambientes de oxidação e temperaturas aos quais as amostras foram submetidas, com uma forte distinção entre 4H-SiC tipo-n e tipo-p. Em geral, amostras do substrato tipo-n apresentaram menores quantidades de defeitos na interface SiO2/SiC em comparação com as do tipo-p. Foram identificados comportamentos relacionados a defeitos no óxido, próximos à interface, responsáveis pela captura de portadores majoritários provenientes do semicondutor. Ficou evidente que alguns ambientes e temperaturas de oxidação beneficiam a interface em detrimento da qualidade do filme de óxido e vice-versa. Uma atmosfera de oxidação alternativa, utilizando H2O2 como agente oxidante, foi proposta. Tal processo mostrou-se eficaz na redução da quantidade de estados eletricamente ativos na interface em estruturas tipo-n através da conversão de compostos carbonados em SiO2 no filme dielétrico formado. / Silicon carbide (SiC) presents many advantageous properties for electronic devices designed to work under extreme conditions such as high-temperature (300 ~ 600 °C), high-frequency, and high-power. In addition, the formation of an insulating oxide layer (SiO2) by thermal oxidation is an attractive property for the microelectronics industry. Nevertheless, large densities of interface states at the SiO2/SiC interface degrade electrical properties of the resulting structure. Such states are responsible for undesirable effects which hamper the development of SiC-based devices. In this thesis, the properties of SiO2/4H-SiC structures obtained by distinct oxidation processes where analyzed and compared. The resulting structures where characterized by currentvoltage, high-frequency capacitance-voltage and ac conductance, X-ray photoelectron spectroscopy, nuclear reaction analysis, and atomic force microscopy. Such techniques were employed in order to correlate electrical and physico-chemical properties of the formed structures like composition and chemical bonding of the oxide layer. Results evidence differences among samples prepared under several oxidation atmospheres and temperatures, with a strong distinction among n- and p-type 4H-SiC. Overall, p-type samples presented larger values of interface states densities in comparison with their ntype counterparts. Near-interface traps in the oxide layer, responsible for capture of majority carriers from the semiconductor substrate, were identified. We could evidence that some oxidation conditions improve the bulk properties of the oxide layer, at the same time that they degrade the SiO2/SiC interface quality, and vice versa. An alternative oxidation process using H2O2 as oxidizing agent was proposed. Such process has shown to reduce the amount of electrically active defects at the interface in n-type samples by converting carbonaceous compounds in SiO2 in the formed dielectric layer.

O presente trabalho, realizado junto ao Grupo de Novos Materiais e Dispositivos (GNMD), no Laboratório de Microeletrônica do Departamento de Sistemas Eletrônicos da Escola Politécnica da USP, visou determinar algumas das propriedades termo-mecânicas de materiais depositados pela técnica de plasma enhanced chemical vapor deposition (PECVD) que são importantes para o desenvolvimento de sistemas microeletromecânicos (MEMS). O módulo de elasticidade, a tensão mecânica residual, o coeficiente de expansão térmica e a condutividade térmica de filmes finos de carbeto de silício amorfo hidrogenado (a-SiC:H) e de oxinitreto de silício (SiOxNy) foram estudados. Medidas de nanoindentação e ressonância de cantilevers foram utilizadas para a obtenção do módulo de elasticidade e os resultados obtidos foram similares (75 e 91 GPa) pelos dois métodos e compatíveis com valores encontrados na literatura. Além disso, obteve-se o módulo de elasticidade de filmes de cromo (285 GPa). A tensão mecânica residual dos filmes utilizados neste trabalho foi medida através da curvatura do substrato induzida pela deposição dos filmes e pela deformação de cantilevers. O valor médio da tensão mecânica, obtido pela curvatura do substrato, variou de -69 MPa até -1750 MPa, mostrando grande dependência das condições de deposição dos filmes. O método que utiliza a deformação de cantilevers possibilitou a obtenção do gradiente de tensão mecânica, que também mostrou uma dependência das condições de deposição, sendo sempre o a-SiC:H quase estequiométrico o menos tensionado. O coeficiente de expansão térmica foi medido utilizando a técnica do gradiente de temperatura e o valor obtido foi similar a valores reportados na literatura para o carbeto de silício cristalino. Para um a-SiC:H quase estequiométrico foi obtido um coeficiente de expansão térmica de 3,41 m/oC, enquanto para um a-SiC:H rico em carbono o valor foi de 4,36 m/oC. Também foi verificado que a variação da resistência do cromo em função da temperatura é pequena, não permitindo sua utilização como sensor de temperatura e inviabilizando a obtenção da condutividade térmica dos filmes estudados. Além disso, foram apresentados trabalhos promissores, mostrando o potencial dos materiais estudados para o desenvolvimento de MEMS. Nesses trabalhos, demonstrou-se a viabilidade de integrar microestruturas atuadas termicamente e guias de onda ópticos, utilizando os materiais estudados neste trabalho. Foram fabricados chaves ópticas, portas lógicas ópticas, fontes de luz integradas e acoplamento das fontes de luz com guias de onda. / This work, realized at the New Materials and Devices Group (GNMD) at the Microelectronics Laboratory of the Department of Electronic Systems of the Polytechnic School of the University of São Paulo, focused at the determination of thermo-mechanical properties of materials deposited by plasma enhanced chemical vapor deposition (PECVD) that are important for the development of microelectromechanical systems (MEMS). The Youngs modulus, the residual stress, the coefficient of thermal expansion and the thermal conductivity of amorphous hydrogenated silicon carbide (a-SiC:H) and silicon oxynitride (SiOxNy) thin films were studied. Nanoindentation and the resonance of cantilevers were used to obtain the Youngs modulus. The results were similar (75 and 91 GPa) with both methods and compatible with literature values. Further, the Youngs modulus of chromium films was also obtained (285 GPa). The residual stress of thin films was obtained through the substrate curvature induced by the film deposition and through the deformation of cantilever beams. The residual stress, obtained through the substrate curvature, varied between -69 MPa and -1750 MPa, showing great dependence on the deposition conditions of these materials. The deformation of cantilevers allowed the determination of the stress gradient and it was also affected by the deposition conditions. In all stress measurements the near stoichiometry a-SiC:H film was less stressed. The coefficient of thermal expansion was measured using the temperature gradient technique and the obtain values were similar to those reported in the literature for crystalline silicon carbide. For a near stoichiometry a-SiC:H film, a value of 3.41 m/oC was obtained, while a carbon rich film showed a thermal expansion coefficient of 4.36 m/oC. It was also verified that the variation of the chromium resistance as a function of temperature is small. This did not allow the utilization of chromium as a temperature sensor, which prevented the obtention of the thermal conductivity of the studied films. Also, some promising works were presented, showing potential applications of the studied materials for the development of MEMS. In these works, the viability of integration of thermal actuated microstructures and optical waveguides was demonstrated. In these works, optical switches, optical logic gates, integrated light sources and coupling of integrated light sources with optical waveguides were presented.

Ce travail de thèse s'inscrit dans le cadre des recherches menées sur les matériaux envisagés pour servir dans les réacteurs nucléaires du futur. Parmi ces matériaux, se trouve le carbure de silicium qui est envisagé comme matériau d'enrobage et de gainage du combustible dans les réacteurs à fission ou comme matériau face au plasma ou constituant les couvertures tritigènes dans les réacteurs à fusion (concept DEMO). Des échantillons de β-SiC ont été frittés par Spark Plasma Sintering. Deux gaz rares abondamment produits en réacteur, le xénon et l'hélium, ont été implantés dans SiC à température ambiante et à plusieurs fluences (Φ1 Xe = 5.1015 at.cm-2 et Φ2 Xe = 1.1017 at.cm-2 pour le xénon et Φ1 He = 5.1015 at.cm-2, Φ2 He = 1.1017 at.cm-2 et Φ3 He = 1.1018 at.cm-2 pour l'hélium). Les échantillons irradiés en xénon ont ensuite été recuits à différentes températures (400 °C, 700 °C et 1000 °C). Une amorphisation complète du matériau a été observée pour toutes les fluences sauf Φ1 He (dpamax = 0,2) ainsi qu'une oxydation notable pour les plus hautes fluences. Un seuil de concentration de formation de bulles dans SiC a pu être déterminé pour l'hélium et le xénon. La coalescence de ces bulles à forte concentration s'est traduite par la formation de cloques sur la surface dans le cas de l'implantation à Φ3 He. A Φ2 Xe, des bulles de plusieurs centaines de nanomètres se sont formées dans la phase oxyde (SiO2 amorphe) alors que la coalescence reste très limitée au sein de la phase SiC résiduelle (nanobulles). Aucun relâchement des espèces implantées n a été mesuré jusqu'à une fluence de 1017 at.cm-2. A Φ3 He, un relâchement important d'hélium s'est produit pendant l'implantation, ce qui indique un effet de saturation dans le matériau. Après traitement thermique à 1000 °C, un relâchement conséquent du xénon contenu initialement dans la phase oxyde a été mesuré alors que le xénon contenu dans la phase SiC semble mieux retenu / This work is part of studies on the proposed materials to be used in future nuclear reactors. Among these materials is silicon carbide, which could be used as a cladding or coating material for the fuel in fission reactors, or as a constituent of plasma facing component or breeding blankets in fusion reactors (DEMO concept). β-SiC samples were synthetized by spark plasma sintering. Two rare gases abundantly produced in reactor, xenon and helium, were implanted in SiC at room temperature and at several fluences (Φ1 Xe = 5.1015 at.cm-2 and Φ2 Xe = 1.1017 at.cm-2 for xenon, Φ1 He = 5.1015 at.cm-2, Φ2 He = 1.1017 at.cm-2 and Φ3 He = 1.1018 at.cm-2 for helium). Xenon irradiated samples were then annealed for two hours at different temperatures (400 °C, 700 °C and 1000 °C). A complete amorphization of the material is observed for all fluences except for Φ1 He (maximum dpa level ≈ 0.2). A significant oxidation is observed for the highest fluences. A threshold concentration for bubble formation has been determined for both species. Bubble coalescence at high concentration results in the surface blistering at Φ3 He. Bubbles of several hundred nanometers were formed in the oxide phase (SiO2) after irradiation at Φ2 Xe, while remaining SiC islands are less subject to coalescence (nanometric bubbles). No gas release could be demonstrated up to a fluence of 1017 at.cm-2. For Φ3 He = 1018 at.cm-2, a significant helium release occurs that could indicate a saturation effect within the material. During thermal treatment at 1000 °C, xenon is retained by carbide phase and highly released by oxide phase

Le principal défi auquel sont confrontés aujourd'hui les équipementiers aéronautiques est d'augmenter l'utilisation des systèmes électriques à bord de l'avion. De nos jours, le remplacement des systèmes hydrauliques par des actionneurs électriques conduit à placer les systèmes électriques dans un environnement hostile, par exemple dans la nacelle du moteur. L'équipement est soumis à des contraintes sévères telles que des températures élevées et basses, un cycle thermique étendu, une humidité élevée et une basse pression. En conséquence, des efforts doivent être faits pour réduire le poids et le volume du convertisseur de puissance sans perdre ses performances. Pour atteindre cet objectif, la conception de modules de puissance doit permettre un haut niveau d'intégration, d'efficacité et de fiabilité. On s’intéresse en particulier aux dommages causés par la fatigue qui ont une influence significative sur les performances électriques de ces modules. Les tests de performance liés à la fatigue restent des efforts coûteux pour l'équipement aéronautique. Un nombre fini de tests destructifs, par vieillissement accéléré, peut être effectué pour un nombre assez faible de configurations. Le but de ces tests est d'étudier les modes de défaillance apparaissant lors du vieillissement accéléré. Par conséquent, des simulations numériques ont été envisagées, facilement évolutives et utilisables pour un grand nombre de configurations, mais nécessitant des données d'essais expérimentaux. Dans ce manuscrit, quelques modes de défaillances sont étudiés. On propose une méthode numérique intégrant les contraintes principales dans les équipements, à savoir la simulation électrique, thermique et mécanique. Ces trois problèmes physiques ont des temps caractéristiques différents et sont fortement couplés avec un comportement non trivial. Pour optimiser l'utilisation des ressources et avoir une représentation pertinente du problème, un procédé couplé électrique 1D / thermique 3D / mécanique 3D a été implémenté sur un bus de cosimulation. Différents pas de temps, différents niveaux d'abstraction et différentes compétences sont utilisés pour fournir un modèle multiphysique de modules de puissance. / Today’s main challenge for aeronautical equipment manufacturers is to respond to the more electrical aircraft regulations. Moreover, there are many applications in aircraft area where high temperature technologies are needed. Nowadays, the replacement of hydraulic systems for electric ones leads to place the power inverters in a harsh environment, for example in the engine nacelle. The equipment is under high constraints such as high and low temperatures, wide temperature cycling, high humidity and low pressure. Combined to these environmental constraints, the new aircraft system is submitted to weight and operating cost reduction. As a consequence, efforts shall be done to reduce weight and volume of the power converter without losing its performance. To reach such a goal, the design of the converter must enable a high level of integration, efficiency and reliability. In particular, fatigue damage has a significant influence on such modules electrical power performance. And fatigue-related performance testing remains a costly endeavor for aeronautical equipment. A finite number of destructive tests can be carried out in specific facilities for a fairly low number of configurations. The purpose of these destructive tests is to investigate the failure modes appearing regarding this accelerated ageing. Therefore numerical simulations have been envisaged since non-destructive, easily evolving and usable for a high number of configurations, though needing data from experimental assays. In this study, we propose a method dealing with the main constraints for such equipment, i.e. electrical, thermal and mechanical simulation. Those three physical problems have different characteristic time and are strongly coupled with a non-trivial behavior. To optimize the resources usage and have a relevant representation of the problem, a 1D electrical / 3D thermal / 3D mechanical coupled method has been implemented over a co-simulation bus. Different time steps, different abstraction levels and different skills are used to provide predictions of the multiphysical fatigue behavior of power modules.

Cette thèse aborde la conception optimale des chaînes de traction par l'exemple d'une chaîne de traction pour métro. Les données d'entrée de la conception d'une chaîne de traction sont la performance attendue et l'encombrement des équipements nécessaires. Pour aider le concepteur, l'outil informatique donne aujourd'hui la possibilité de construire une grande variété de modèles. D'autre part, les algorithmes d'optimisation permettent de trouver les configurations optimales. Ces possibilités ont été exploitées au cours de ce travail. Les modèles développés permettent d'estimer un large nombre de critères. A travers l'exemple de ces modèles, la méthode de conception suivie est détaillée dans le rapport. D'un point de vue technique, la chaîne de traction proposée est détaillée dans le dernier chapitre / This thesis deals with the optimal design of electric drivetrains. A drivetrain for metro is taken as an example. The input data for the design are the expected performance and the size of the required equipments.To assist the designer, the computing tool now gives the opportunity to build different sort of models. In addition, optimization algorithms allow finding optimal configurations. This work is an attempt to exploit these possibilities. The design models are used to value a large number of criteria. Through the example of these models, the design method followed is detailed in the document. From a technical point of view, the proposed drivetrain is detailed in the last chapter

Les matériaux céramiques sont des composants incontournables dans les blindages antibalistiques multicouches. Leur faible densité, typiquement deux à trois fois inférieure à celle de l’acier, combinée à une très haute résistance en compression les rends essentiel pour des applications d’armures légères. Le carbure de silicium est un matériau prometteur pour cette application en raison de sa faible densité et de sa dureté élevée en comparaison des autres céramiques. L’étude du lien entre la microstructure du matériau et son processus de fragmentation pendant l’impact est une étape importante afin d’optimiser les céramiques pour les applications de protection balistique.Quatre nuances de carbure de silicium denses avec différentes microstructures ont été étudiées, dont trois élaborées au cours de ces travaux. Pour cela, deux modes de frittage ont été utilisés (frittage en phase solide et frittage en phase liquide) ainsi que deux procédés de frittage (frittage naturel et frittage flash). Un soin particulier a été porté aux diverses étapes de la fabrication afin de produire des microstructures homogènes et denses. Des pièces de taille satisfaisante pour l’application ont été réalisées pour chaque nuance. Elles ont été soumises à des caractérisations microstructurales (microscopie électronique à balayage et en transmission, diffraction des rayons X, cartographie élémentaire, analyses chimiques) et mécaniques en quasi-statique (dureté, ténacité, contrainte à la rupture, module de Weibull) et en dynamique. La fragmentation dynamique des carbures de silicium a été étudiée grâce à des essais utilisant une configuration d’impact sur la tranche. Une première configuration a permis d’observer la phénoménologie et la chronologie de l’endommagement du matériau grâce à une caméra ultra-rapide. Une seconde configuration ‘sarcophage’ a permis d’observer la fragmentation des matériaux, c’est-à-dire le motif et la densité de fissuration des cibles. Il a été observé que la microstructure joue un rôle clef sur l’intensité de l’endommagement subit par la céramique pendant l’impact. Une bonne adéquation avec des simulations utilisant le modèle d’endommagement anisotrope Denoual-Forquin-Hild (DFH) a été mise en évidence. Une autre configuration expérimentale mettant en oeuvre un double impact sur une même cible a été utilisée afin de caractériser la résistance de la céramique endommagée. En parallèle, des essais balistiques avec des munitions 7,62x54mmR API B32 et 7,62x51mm AP8 ont été réalisés. La microstructure des céramiques a montré jouer un rôle important sur la performance balistique / Ceramics are a key component in multilayer armor structures. Their low density, typically two to three times lower than steel, combined with a high compressive strength make them essential materials for lightweight armor solutions. Silicon carbide is a promising material for this application due to its particularly low density and high hardness, even among other ceramics. However, armor performance is controlled by more than just the composition and understanding the link between the ceramic microstructure and the fragmentation process during the impact is essential to produce optimized and high performance materials for armor applications.Four dense silicon carbide grades with various microstructures have been used, including three produced during this work. For that, two sintering modes (solid state sintering and liquid phase sintering) and two sintering processes (pressureless sintering and spark plasma sintering) have been used. Particular care has been taken with ceramic processing in order to produce different homogenous and dense microstructures. Silicon carbide parts have been produced at a sufficient size for the application. They were submitted to microstructural characterization (scanning and transmission electronic microscopy, X-ray diffraction, elemental cartography, chemical analysis) and mechanical characterization in quasi-static mode (hardness, toughness, module of rupture, Weibull modulus) and dynamic mode. Dynamic fragmentation of silicon carbide grades has been studied by means of Edge-On Impact (EOI) experiments. A first configuration enabled the study of the damage process that spreads out within the tile thanks to an ultra-high speed camera. A second ‘sarcophagus’ configuration was used to enable observation of the target fragmentation, i.e., crack patterns and crack densities. It has been observed that the microstructure of ceramics plays a key role in the damage intensity generated during impact. A good match with a simulation using the Denoual-Forquin-Hild (DFH) anisotropic damage model has been highlighted. Another experimental configuration implying a double impact on ceramics has been used to characterize the resistance of the damaged target. In parallel, ballistic experiments with 7.62 x54mmR API B32 and 7.62x51mm AP8 threats have been performed. Microstructure of ceramics has been shown to play an important role on ballistic performance

No description available.

Les organes de frottement en carbure de silicium répondent à des critères de fonctionnement exigeants grâce aux propriétés offertes par cette céramique. Son faible coefficient de dilatation thermique et sa bonne conductivité thermique la rendent moins sensible aux chocs thermiques que les autres céramiques et particulièrement, en frottement, où la génération locale de chaleur peut s’avérer importante. Ces performances tribologiques sont conditionnées par son environnement mécanique, par la nature de la face de frottement antagoniste et surtout par le comportement des éléments interfaciaux circulant dans le contact. Le frottement du couple homogène SiC/SiC dans une configuration anneau/anneau a tout d’abord été étudié et son mécanisme d’usure a été établi, montrant un glissement sec difficile et une usure prononcée. Des alternatives ont alors été étudiées : revêtement du carbure par du DLC ou remplacement de la contreface par une bague carbone-graphite. Les imprégnations des bagues carbone-graphites par différents composés, polymères avec la résine phénolique et le PTFE ou métallique avec l’antimoine permettent d’en façonner les propriétés et, par conséquent, la réponse tribologique. Les essais sont réalisés à l’aide d’un tribomètre en glissement rotatif et ont permis de caractériser ces comportements tribologiques en fonction de différentes conditions de pression de contact, de vitesse et de température. Une analyse thermique a également été développée grâce à l’utilisation d’une caméra thermique infrarouge et a permis d’identifier les flux thermiques et le champ de températures durant le frottement. Des analyses physico-chimiques par EDS et spectroscopie Raman ont permis de décrire les transferts de matière mis en jeu et ont mis en évidence des phénomènes locaux d’oxydation de l’interface. La forte participation des imprégnants du carbone-graphite à la formation du troisième corps a été montrée. La spectroscopie Raman a également permis d’étudier le caractère cristallin des surfaces et du troisième corps formé et de mettre en évidence des phénomènes de contraintes en surface à l’origine des mécanismes d’endommagement. Il a ainsi pu être reconstitué un scénario complet des différentes étapes du glissement en termes de bilans de matière et d’énergie dans le contact. / Silicon carbide friction bodies fulfill high operation criteria owing to the properties provided by this ceramic. Its low thermal expansion coefficient and good thermal conductivity make it less sensitive to thermal shocks than other ceramics and particularly in friction, where the local heat generation may be significant. These tribological performances are then conditioned by the mechanical environment, by the nature of the counterface and above all by the interfacial elements circulating inside the contact. The friction of the homogeneous SiC/SiC pair in a ring-on-ring configuration was first studied and its wear mechanism was redefined. A hard silicon carbide counterface showed a difficult dry sliding and a high wear, alternative materials were studied: DLC coating on silicon carbide rings or carbon-graphite rings. Impregnation of the carbon-graphite rings with different compounds, polymers with the phenolic resin and PTFE or metal with antimony, shaped its properties and therefore, the tribological behaviour. Friction tests are carried out using a rotary sliding tribometer. They characterized the tribological behaviour for different operating conditions of contact pressure, sliding velocity and temperature of the environment. In addition, a thermal analysis was also implemented by using an infrared thermal camera in order to identify heat flows in the system and the temperature field for the entire duration of the tests. Physico-chemical analysis using EDS and Raman spectroscopy permitted to describe the transfers of material which take place during the tests and highlighted the local oxidation phenomena of the interface. The strong contribution of the carbone-graphite impregnants to the formation of the third body was also shown. Raman spectroscopy was also used to examine the crystalline state of the surfaces and the third body. Raman spectroscopy highlighted also stresses which are the source of the damage mechanisms. The different stages of the phenomena taking place during sliding inside the contact in terms of material and energy balance were then described.