Academic literature on the topic 'Oxide silicium'
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Journal articles on the topic "Oxide silicium"
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Hodek, Jiří, Milan Šípek, and Oskar Šlechta. "Permeation and sorption methods for the determination of transport parameters of gases and vapours through flat membranes." Collection of Czechoslovak Chemical Communications 54, no. 11 (1989): 2919–32. http://dx.doi.org/10.1135/cccc19892919.
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New relations were derived for the determination of diffusion coefficients, coefficients of permeability, and sorption coefficients of gases and vapours through flat membranes by means of the permeation and sorption methods. To verify these relations, a polyurethane filled with silicium oxide (Silica) was chosen as a model system. Transport parameters of water vapours at the temperature of 25 °C were determined of this system by the sorption and permeation methods. Both the methods yield practically the same transport parameters especially after evacuating the membrane before the measurement by the permeation technique.
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Lima, N. M. O., Crislene Rodrigues da Silva Morais, L. M. R. Lima, and A. V. Albuquerque. "Electronic Waste: Characterization of the Glass of Cathode Ray Tube Computer for Making Decorative Pieces by Recycling." Materials Science Forum 727-728 (August 2012): 1525–29. http://dx.doi.org/10.4028/www.scientific.net/msf.727-728.1525.
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The vigorous industrialization of the modern world and the incorporation of new consumption habits of society made appears electronic waste. This work had as objective to collect and characterize vitreous residues originating from Cathode Ray Tubes or, popularly, "image tubes", identified for the acronym CRT, which integrate computers monitors that will be recycled in the production of handicrafts. For its characterization were used techniques: X-Ray Fluorescence, Granulometric Analysis, X-Ray Diffraction. After analyses it was observed that glasses of the screen and of the funnel presented different chemical compositions, being silicium oxide (SiO2) the component of larger percentage in these glasses, 59.89% and 48.63%, for screen and funnel, respectively. Funnel presented 29.47% of lead oxide (PbO) while this oxide is absent in the screen. Screen presents significant amounts of barium oxide (10.75%) and strontium oxide (7.71%). Vitreous samples X-ray diffractions of residues of the funnel and the screen are to each other similar, presenting an amorphous band that indicates silica presence, with absence of crystalline phases. Through the presented results can be concluded that computer monitors CRTs has potential for be recycled, because present great amounts of SiO2, oxide that forms the vitreous net.
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Минаков, А. В., А. С. Лобасов, М. И. Пряжников, Л. С. Тарасова, Н. Я. Василенко, and В. Я. Рудяк. "Экспериментальное исследование влияния наночастиц на процессы испарения жидкостей." Журнал технической физики 90, no. 1 (2020): 33. http://dx.doi.org/10.21883/jtf.2020.01.48657.61-19.
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Evaporation of nanofluids based on distilled water and the silicium and zirconium dioxides, aluminium oxide as well as the diamond has been experimentally studied. The average diameter of the SiO2 nanoparticles was 25 nm, of the ZrO2 nanoparticles was 105 nm, of the Al2O3 nanoparticles was 43 nm and of the diamond nanoparticles was 5 nm. The synchronous thermoanalyser STA 449 С Jupiter was used in the investigation of the evaporation processes. The dependences of the evaporation rate on the volume concentration of the nanoparticles were obtained as a result of the experimental studies. It was shown that as the nanoparticles volume concentration increases the nanofluids evaporation rates monotonically increase too.
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Wedel, B., K. Sugiyama, K. Hiraga, and K. Itagaki. "Zur Kristallchemie des ersten Blei-Zink-Silicium-Telluroxids: PbZn4SiTeO10 / On the Crystal Chemistry of the First Lead Zinc Silicon Tellurium Oxyde PbZn4SiTeO10." Zeitschrift für Naturforschung B 54, no. 4 (April 1, 1999): 469–72. http://dx.doi.org/10.1515/znb-1999-0409.
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Single crystals of the new lead zinc silicon tellurium oxide PbZn4SiTeO10 have been prepared by solid state reaction in air. The compound is colourless and crystallizes in orthorhombic symmetry, space group D162h Pnma, with the cell parameters: a = 6.542 (5), b = 15.624(4), c = 8.280(4) Å, Z = 4. The structure has been determined from a single crystal X-ray study and refined to the conventional values R = 0.032 and wR(F2) = 0.050. Zn2+ and Si4+ show tetrahedral and Te6+ octahedral coordination by O2-.The crystal structure is dominated by a 3∞ [Zn4O10]12- framework with isolated TeO66+ and SiO44+ polyhedra. Pb2+ ions are incorporated in the network. The centres of negative charge of the lone pairs of Pb2+ are estimated by calculations of the Coulomb term of the lattice energy
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Shadrin, K. V., Viktoria V. Panteleeva, and А. B. Shein. "Passivation of chromium disilicide in acidic media." Вестник Пермского университета. Серия «Химия» = Bulletin of Perm University. CHEMISTRY 11, no. 3 (2021): 202–11. http://dx.doi.org/10.17072/2223-1838-2021-3-202-211.
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The anodic behavior of CrSi2 electrode in 0,5 M H2SO4, 0,5 M HClO4, 0,5 M HNO3 and 0,5 M HCl solutions has been studied by the methods of polarization, capacitance, and impedance measurements. It has been concluded that in the process of anodic oxidation at potentials from corrosion E to transpassivation E inclusive, an oxide film is formed on the surface of chromium disilicide in the studied media, which is close in composition to SiO2 (with a small content of chromium oxides). The presence of this film on the silicide surface determines its high chemical resistance in the studied solutions. The thickness of the oxide film on CrSi2 has been calculated depending on the potential and composition of the electrolyte. The growth constant of the oxide film has been determined.
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Logvinova, Alla, Dmitry Zedgenizov, and Richard Wirth. "Specific Multiphase Assemblages of Carbonatitic and Al-Rich Silicic Diamond-Forming Fluids/Melts: TEM Observation of Microinclusions in Cuboid Diamonds from the Placers of Northeastern Siberian Craton." Minerals 9, no. 1 (January 15, 2019): 50. http://dx.doi.org/10.3390/min9010050.
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The microinclusions in cuboid diamonds from Ebelyakh River deposits (northeastern Siberian craton) have been investigated by FIB/TEM techniques. It was found that these microinclusions have multiphase associations, containing silicates, oxides, carbonates, halides, sulfides, graphite, and fluid phases. The bulk chemical composition of the microinclusions indicates two contrasting growth media: Mg-rich carbonatitic and Al-rich silicic. Each media has their own specific set of daughter phases. Carbonatitic microinclusions are characterized by the presence of dolomite, phlogopite, apatite, Mg, Fe-oxide, KCl, rutile, magnetite, Fe-sulfides, and hydrous fluid phases. Silicic microinclusions are composed mainly of free SiO2 phase (quartz), high-Si mica (phengite), Al-silicate (paragonite), F-apatite, Ca-carbonates enriched with Sr and Ba, Fe-sulfides, and hydrous fluid phases. These associations resulted from the cooling of diamond-forming carbonatitic and silicic fluids/melts preserved in microinclusions in cuboid diamonds during their ascent to the surface. The observed compositional variations indicate different origins and evolutions of these fluids/melts.
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Nakamura, Kozo, and Junsuke Tomioka. "Effect of Oxygen Precipitates on the Surface-Precipitation of Nickel on Cz-Silicon Wafers." Solid State Phenomena 108-109 (December 2005): 103–8. http://dx.doi.org/10.4028/www.scientific.net/ssp.108-109.103.
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This paper presents a model for the analysis of the surface nucleation and growth of Ni silicide on silicon wafers contaminated by Ni. The model can additionally be used to characterize the gettering reaction of Ni induced by oxygen precipitates. We also discuss the relation between the surface precipitation of Ni silicide and the gettering ability of oxygen precipitate. The surface precipitation of Ni silicide depends on the total surface area of oxide precipitates. When the total surface area of the oxide precipitates exceeds the critical value, the surface precipitation is rapidly suppressed. Our model can explain the phenomenon of the gettering threshold in the following manner. 1) The gettering of Ni by oxygen precipitates is a reaction-limited process at the interface between oxygen precipitate and silicon, as Sueoka proposed. 2) The residual Ni concentration in this reaction-limited gettering process continuously decreases as the total surface area of the oxide precipitates increases. 3) The surface precipitation of Ni silicide is rapidly suppressed when the residual Ni concentration falls below the critical concentration. Our calculation results correspond well with the experimental results.
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Rosales, I., D. Ponce, MJ Garcia-Ramirez, and R. Guardian. "Effect of Chromium Addition on the Cyclic Oxidation Resistance of Pseudo-Binary (Mo,Cr)3 Si Silicide Alloy." High Temperature Materials and Processes 37, no. 9-10 (October 25, 2018): 943–49. http://dx.doi.org/10.1515/htmp-2017-0099.
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AbstractThis paper describes the performance under cyclic oxidation of (Mo,Cr)3 Si compound with different Cr additions for possible coating application. Cyclic oxidation was carried out at 1,000 °C at different intervals during 250 h. Oxidized surface samples were analysed by scanning electron microscope where epitaxial oxide scales were observed mainly in samples with higher Cr content which may provide protection against surface oxidation. X-ray diffraction studies have shown the Cr2O3 and SiO2 formation as the main oxide scale; after analyses, it was found that these oxides are responsible for the best oxidation protection, with 36 at.% Cr being the optimal chromium concentration. At lower chromium concentrations, pest reaction occurred in the oxidized samples at times less than 25 h as a result of the formation of the unstable molybdenum oxide.
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Han, Jiesheng, Bo Su, Junhu Meng, Aijun Zhang, and Youzhi Wu. "Microstructure and Composition Evolution of a Fused Slurry Silicide Coating on MoNbTaTiW Refractory High-Entropy Alloy in High-Temperature Oxidation Environment." Materials 13, no. 16 (August 14, 2020): 3592. http://dx.doi.org/10.3390/ma13163592.
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In this paper, the Si-20Cr-20Fe coating was prepared on MoNbTaTiW RHEA by a fused slurry method. The microstructural evolution and compositions of the silicide coating under high-temperature oxidation environment were studied. The results show that the silicide coating could effectively prevent the oxidation of the MoNbTaTiW RHEA. The initial silicide coating had a double-layer structure: a high silicon content layer mainly composed of MSi2 as the outer layer and a low silicon content layer mainly contained M5Si3 as the inner layer. Under high-temperature oxidation conditions, the silicon element diffused from the silicide coating to the RHEA substrate while the oxidation of the coating occurred. After oxidation, the coating was composed of an outer oxide layer and an inner silicide layer. The silicide layer moved toward the inside of the substrate, led to the increase of its thickness. Compared with the initial silicified layer, its structure did not change significantly. The structure and compositions of the oxide layer on the outer surface strongly depended on the oxidation temperature. This paper provides a strategy for protecting RHEAs from oxidation at high-temperature environments.
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Hope, GA, and DK Pham. "Platinum Silicide/n-Silicon Photoelectrodes: Properties and Characteristics of the Platinum Silicide Layer." Australian Journal of Chemistry 40, no. 3 (1987): 443. http://dx.doi.org/10.1071/ch9870443.
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The surface analysis of thermally grown platinum silicide layers on single crystal silicon wafers has shown that silicide phase growth can occur for thin films. The depth profile was found to depend upon the temperature at which the silicide was formed, the length of time for which the reaction proceeded and the supply of platinum. The ESCA peaks for Pt and Si were shifted in energy from the elemental values in the silicide layer. A surface oxide, assigned as SiO2 from the Si 2p signal, was detected on all samples. The platinum signal broadened considerably when the silicide layer had been largely removed by sputtering, and appeared to consist of two components.
Dissertations / Theses on the topic "Oxide silicium"
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Rauer, Caroline. "Collage de silicium et d'oxyde de silicium : mécanismes mis en jeu." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENI088/document.
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Le collage direct consiste en la mise en contact de deux surfaces suffisamment lisses et propres pour qu'une adhésion puisse se créer sans ajout de matière à l'interface. Ce procédé réalisable à l'échelle industrielle trouve son intérêt dans l'empilement de structures ou de matériaux pour la microélectronique ou les microtechnologies. Il s'avère alors important de maîtriser ce procédé et cela passe notamment par la compréhension des mécanismes physico-chimique se produisant lors du collage. Le but de ce travail de thèse est donc l'étude des mécanismes mis en jeu dans le collage hydrophobe de silicium et le collage hydrophile d'oxydes de silicium déposés.Dans cette étude, des procédés de collage direct hydrophobe de plaques de silicium (100) reconstruit ont été développés, ainsi que des collages de surfaces hydrophiles d'oxyde de silicium déposés préparées par des activations plasma azote ou oxygène ou par un procédé de polissage mécano-chimique. Le comportement de toutes ces structures a été étudié à plusieurs stades du procédé, en particulier lors des traitements thermiques de consolidation de l'interface de collage. Pour ce faire, différentes techniques de caractérisation ont été mises en oeuvre comme la mesure d'énergie de collage, l'observation de la défectivité par microscopie acoustique, la spectroscopie infrarouge et la réflectivité des rayons X. Cela a ainsi permis de suivre la fermeture de l'interface de collage en température d'un point de vue chimique et mécanique et des mécanismes de collage ont alors pu être proposés pour toutes les structures étudiées. Des recommandations ont également pu être faites pour l'obtention de collages d'oxydes de silicium déposés efficaces et de qualitéDirect wafer bonding refers to a process by which two mirror-polished wafers are put into contact and held together at room temperature by adhesive force, without any additional material. This technology feasible at an industrial scale generates wide interest for the realization of stacked structures for microelectronics or microtechnologies. In this context, a precise understanding of bonding mechanisms is necessary. Consequently, the aim of this work is to study the bonding mechanisms for hydrophobic silicon reconstructed surfaces and hydrophilic deposited silicon oxides surfacesIn this study, bonding of hydrophobic silicon reconstructed surfaces and bonding of hydrophilic deposited silicon oxides prepared either by plasma activation or chemical-mechanical polishing were analyzed, as a function of post-bonding annealing temperature. For this, several characterization techniques have been used: bonding energy measurement, acoustic microscopy in order to observe defectivity, infrared spectroscopy and X-Ray reflectivity. Thus the bonding interface closure has been analyzed from a chemical and mechanical point of view and bonding mechanisms have been proposed for the studied bonded structures. Finally the study of deposited silicon oxide bonding prepared either by plasma activation or by chemical-mechanical polishing has lead to some recommendations for efficient and high quality deposited silicon oxides bonding
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Nicolaï, Julien. "Caractérisation, compréhension et modélisation de l'évolution des défauts induits par des cycles thermiques dans le silicium." Thesis, Aix-Marseille, 2012. http://www.theses.fr/2012AIXM4305/document.
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Le silicium est le matériau de prédilection de l'industrie de la microélectronique. L'augmentation du coût de celui-ci a donc incité les différentes industries à optimiser l'utilisation des plaquettes de silicium. La réutilisation de plaquettes (recyclage) est donc devenue monnaie courante : c'est le cas des plaquettes tests ou des plaquettes de type SOI. Le recyclage présente cependant des limites, en effet, au cours des cycles la qualité des plaquettes diminue plus ou moins rapidement. La compréhension des mécanismes de la dégradation des plaquettes lors de cycles de procédés est donc un enjeu important. Les procédés de recuit haute température sont connus pour être à la fois les plus répandus et les plus dégradants. Pour comprendre quels sont les phénomènes mis en jeu lors de tels cycles, un panel d'échantillons a subi différents nombres de cycles et a été étudié par diverses techniques. Le LST et la microscopie électronique en transmission ont tout particulièrement été utilisés, couplant ainsi des mesures globales de densités et dimensions de défauts à des mesures locales permettant de caractériser la nature des défauts et leur comportement à l'échelle nanométrique. L'évolution de la concentration en oxygène interstitiel dans le matériau, liée à la précipitation d'oxyde de silicium, a été mesurée par IRTF. Il a ainsi été montré que chaque cycle consistait en une étape de nucléation de défauts, principalement des précipités d'oxyde de silicium, et une étape de grossissement. La détermination de la morphologie, ainsi que de la stoechiométrie des précipités a été réaliséeSilicon is the prefered material of the Microelectronics industry. The increase of its cost incited the industries to optimize the use of wafers. Recycling them thus became current : it is the case for test wafers or SOI wafers. However, recycling presents limits : during the cycles, wafers quality decreases more or less quickly. Impact of process cycles on wafers quality is thus very important. High-temperature annealing is the most detrimental process. To understand what phenomena are involved during annealing cycles, samples which have been cycled were studied by differents techniques. LST and TEM were quite particularly used, coupling global measurements of defects density and size with local measurements to determine defects characteristics. Interstitial oxygen loss during cycles were measured by FTIR. We found that every cycle is composed by a defects nucleation stage, mainly precipitates of silicon oxide, and a growth stage. The determination of morphology and precipitates stoichiometry was realized. The behavior of these precipitates was described by a model taking into account various phenomena : oxygen loss, point defects distribution and cycles effects (ramp up/down and high-temperature stage). The robustness of the model was also tested by comparing the predictions made with the results taken from the bibliography
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Mortada, Oussama. "Conception et réalisation de micro-résonateurs piezoélectriques sur substrat de silicium sur isolant." Thesis, Limoges, 2016. http://www.theses.fr/2016LIMO0075/document.
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Les ondes acoustiques, démontrées théoriquement en 1885 par le scientifique anglais Lord Rayleigh, constituent de nos jours un sujet de recherches très intéressant. Elles sont devenues indispensables à la fabrication des systèmes de télécommunication miniatures et performants, tels que par exemple les filtres, les oscillateurs ou encore les capteurs. Les dispositifs fonctionnant grâce aux ondes acoustiques sont connus sous le nom de « dispositifs piézoélectriques » puisqu’ils transforment les signaux RF en ondes acoustiques, et vice versa, grâce au phénomène piézoélectrique direct. Le développement de ces dispositifs piézoélectriques a été indispensable pour répondre aux exigences particulières et extrêmes des systèmes de télécommunication actuels (sélectivité, miniaturisation, faible coût, facilité de fabrication et d’intégration). Cette thèse s’inscrit dans une démarche générale de développement des dispositifs piézoélectriques, notamment des micro-résonateurs piézoélectriques qui en constituent la dernière génération. Deux axes principaux ont été développés au cours de ces travaux de recherches : l’étude théorique des micro-résonateurs piézoélectriques à travers une modélisation électrique d’une part, et, d’autre part, la description des procédés de fabrication réalisés en salle blanche du laboratoire d’XLIMThe acoustic waves, theoretically demonstrated in 1885 by the English scientist Lord Rayleigh, are nowadays an interesting research subject. It became essential to the fabrication of miniature and efficient systems of telecommunication, such as filters, oscillators or sensors. Devices using the acoustic waves are known as piezoelectric devices, because they transform RF signal into acoustic waves, and vice versa, thanks to the direct piezoelectric phenomenon. The development of these piezoelectric devices was essential to meet the particular and extreme requirements of the current systems of telecommunication (selectivity, miniaturization, low cost, ease of manufacturing and integration). This thesis is part of a global approach to develop the piezoelectric devices, notably the piezoelectric micro-resonators which constitute the latest generation. Two main axes have been developed during the research work: the theoretical study of piezoelectric micro-resonators through an electric modelling, on one hand, and, on the other hand, the description of the manufacturing processes accomplished in clean room of XLIM’s laboratory
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Benhammou, Younes. "Développement de SPADs (Single Photon Avalanche Diodes) à cavité de germanium sur silicium en intégration 3D avec une technologie silicium CMOS 40nm." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI123.
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Cette thèse porte sur une famille de photo-détecteurs appelés SPAD pour Single Photon Avalanche Diodes qui sont des jonctions PN polarisées en inverse au-delà de la tension de claquage. Les diodes SPADs sont reconnues pour présenter de très bonnes performances en détection de faibles flux lumineux avec une réponse extrême rapide. Afin d’améliorer l’efficacité de détection dans le proche infrarouge de diodes SPAD sur silicium, les objectifs de la thèse sont de concevoir, fabriquer et caractériser une nouvelle génération de photodiodes SPADs dans une technologie CMOS 40nm en intégrant une cavité de germanium. Les travaux menés comportent i) un volet conception en utilisant des outils de simulation TCAD pour proposer une architecture originale optimisée, ii) le développement du flot complet du procédé technologique avec la création de nouvelles briques telles que la gravure de la cavité et l’épitaxie de germanium dopé in-situ, 3) la caractérisation électro-optique des composants issus des premiers lots fabriqués. Les analyses et interprétations des résultats obtenus révèlent la difficulté technologique pour réaliser une hétérojonction silicium-germanium sans défauts et une couche germanium de qualité. Néanmoins, les mesures réalisées ont démontré la capacité de cette nouvelle famille de SPAD à cavité de germanium sur plateforme silicium pour détecter les flux jusqu’à 1300nm, démontrant un fort potentiel applicatif pour les applications d’aide à la navigationThis thesis deals with a family of photo-detectors called SPAD for Single Photon Avalanche Diodes which are a PN junctions reverse biased beyond the breakdown voltage. SPADs diodes are known to have very good performance in detecting low light fluxes with an extremely fast response. In order to improve the near infrared detection efficiency of SPAD diodes on silicon, the objectives of the thesis are to design, manufacture and characterize a new generation of SPAD photodiodes in 40nm CMOS technology by integrating a germanium cavity. The work carried out includes i) design and simulation using TCAD tools to propose an optimized original architecture, ii) development of the process flow in industrial imager technological with the creation of new bricks such as etch of the cavity and epitaxy of germanium in-situ doped 3) the electro-optical characterization of the manufactured devices. The results obtained reveal technological difficulty to produce a silicon-germanium heterojunction without defects. Nevertheless, the measurements carried out demonstrated the ability of this new family of germanium cavity SPADs on a silicon platform to detect wavelengths up to 1300nm, demonstrating a strong potential for time of light applications
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Ventosa, Caroline. "Étude des mécanismes mis en jeu dans le collage direct de surfaces hydrophiles." Université Joseph Fourier (Grenoble ; 1971-2015), 2009. http://www.theses.fr/2009GRE10214.
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Le collage par adhésion moléculaire consiste en la mise en contact de deux surfaces suffisamment lisses et propres, afin de créer une adhésion entre elles. Cette technologie renferme de nombreux intérêts dans la réalisation de structures empilées pour la microélectronique, et des micro-technologies. Le collage par adhésion molécualire voit donc son utilisation grandir et s'étendre à de nouveaux matériaux. De ce fait, une bonne maîtrise de cette technologie s'avère être indispensable et ceci ne peut avoir lieu sans une compréhension précise et approfondie des mécanismes physico-chimiques se produisant lors du collage. Le but de ce travail de thèse est donc l'étude des mécanismes mis en jeu dans le collage par adhésion moléculaire, de matériaux connus : le silicium et l'oxyde de sislicium dont les surfaces sont rendues hydrophiles avant collage. Dans cette étude, les mécanismes de collage sont établis à l'aide d'un modèle de contact par aspérités. En effet, la microrugosité des surfaces permet d'expliquer une fermeture de l'interface de collage par grossissement des aspérités en contact, et non par rapprochement des surfaces considéré jusqu'à présent. Il est démontré que le modèle de contact par aspérités établi préalablement à partir d'un collage Si-Si hydrophobe, est entièrement transposable aux collages hydrophiles de structures Si-Si, Si-SiO2 et SiO2-SiO2. Le comportement des films d'oxyde en surface des substrats de silicium, sont étudiés à plusieurs stades du procédé, en particulier lors des traitements thermiques de consolidation. Pour se faire, deux techniques complémentaires sont utilisées principalement : la réflexivité des rayons X et la spectroscopie infrarouge. Enfin, cette étude se termine par la validation des mécanismes proposés via l'analyse de collages de structures Si-Si "modifiées" par l'utilisation de traitements de surfaceDirect wafer bonding refers to a process by which two mirror-polished wafers are put into contact and held together at room temperature by adhesive forces, without any additional materials. This technology contains many interests applied to the realization of stack structures microelectronic or micro-technologies. Therefore, the use of direct wafer bonding is growing and extending to various materials. In this context, a precise understanding of bonding mechanisms is necessary to the control of the wafer bonding technology. Consequenltly, the aim of this work is to study wafer bonding mechanisms in the case silicon and silicon oxide substrates, with hydrophilic surfaces. In this study, mechanisms are proposed thanks to a rough surface model. Indeed, the surface roughness allows one to explain the interface closure through an increase of the contact points. It is put in evidence that the interface closure does not occur through a rapprochement of surfaces presented until now. We showed that the rough surface model previously created from hydrophobic Si-Si bonding, is entirely transposable to hydrophilic bonding of Si-Si, Si-SiO2 and SiO2-SiO2 structures. The behavior of silicon oxide layers is studied as a function of the post-bonding annealing temperature and for different processes. For this, two complementary characterization techniques have been used : X-Ray Reflectivity and infrared spectroscopy. Finally, the validation of the wafer bonding mechanisms has been demonstrated through Si-Si bonding, of which the surface has been modified
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Gelin, Simon. "Dépôt de films d'oxyde de silicium par vaporisation sous vide : dynamique moléculaire et expériences." Thesis, Paris Est, 2016. http://www.theses.fr/2016PESC1117/document.
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Les films de silice dont sont constitués les traitements antireflets des verres de lunettes sont déposés par vaporisation au canon à électrons, à température ambiante. Ils sont le siège de fortes contraintes résiduelles compressives qui diminuent considérablement leur stabilité mécanique. Ces contraintes sont difficiles à contrôler parce que les paramètres process qui les affectent sont très nombreux: propriétés du substrat, du gaz résiduel, caractéristiques de l’enceinte et du canon à électrons, vitesse de croissance,… Ils ne sont par ailleurs pas tous indépendants et agissent souvent sur plusieurs phénomènes physiques à la fois. Dans cette thèse, nous mettons en œuvre des simulations numériques et des expériences pour identifier les mécanismes à l’origine de la mise en compression des films de silice pendant leur croissance. Les expériences nous permettent de distinguer trois régimes de croissance, en fonction de la pression de gaz résiduel. Sous vide très poussé, où le gaz a un rôle négligeable, les films croissent en compression. Ensuite, à mesure que la pression augmente, l’incorporation d’espèces issues du gaz dans les films les comprime légèrement. Enfin, lorsque la pression augmente encore, le ralentissement des particules vaporisées par le gaz diminue fortement le niveau de compression et masque l’effet d’incorporation. Les dépôts de silice par dynamique moléculaire nous permettent d’explorer la limite de vide idéal. Grâce à une étude paramétrique systématique, nous trouvons que la mise en compression des films est exclusivement contrôlée par l’énergie cinétique moyenne des particules incidentes. En outre, les valeurs expérimentales ne peuvent être retrouvées qu’avec une énergie de quelques eV, au moins dix fois plus grande que toutes les prédictions formulées dans la littérature sur le dépôt. Ce résultat inattendu nous conduit à réfuter l’idée que la vaporisation au canon à électrons procéderait par simple échauffement thermique. Nous le confirmons en déposant expérimentalement des films à partir de monoxyde de silicium, évaporé thermiquement ou vaporisé au canon à électrons: les premiers croissent en tension, les seconds en compression. Finalement, pour expliquer les quelques eV prédits, nous proposons que sous irradiation électronique, une concentration de charges se forme à la surface de la silice en raison de sa très faible conductivité électrique. Les particules vaporisées qui sont chargées sont alors accélérées par répulsion CoulombienneSilica thin films are widely used as low index layers in antireflective coatings. In the ophthalmic industry, they are deposited at ambient temperature, by electron beam vaporization. This process generates large compressive stresses which make the coatings susceptible to damage. It is thus crucial to understand how these stresses emerge. However, this problem is highly complex because many process parameters may play a role: substrate and residual gas properties, characteristics of the deposition chamber, of the electron gun, growth rate,… Moreover, these parameters may depend on each other and affect several phenomena at the same time. In this thesis, numerical simulations and experiments are performed in order to identifiy the mechanisms responsible for the generation of compressive stresses during film growth. The experiments reveal three regimes of growth, depending on the residual gas pressure. Near ultra high vacuum, where the effect of residual gas is negligible, films grow under compression. Then, as pressure increases, incorporation of gas species in the films slightly compresses them. Eventually, when pressure is high enough so that vaporized particles are slowed down by collisions with gas particles, the level of compression significantly decreases; this rapidly masks the incorporation effect. Molecular dynamics simulations allow us to explore the ideal vacuum limit. By depositing silica films in a vast ensemble of conditions, we find that their compressive state of stress is solely controlled by the mean kinetic energy of incident particles. Comparison with experiments suggests that this energy is equal to a few eV, which is at least ten times greater than predictions from the literature on deposition. This unexpected result leads us to refute the idea that electron beam vaporization would be equivalent to simple themal heating. We confirm this experimentally, by comparing films deposited from silicon monoxide either thermally evaporated or vaporized using an electron beam: the formers grow under tension while the latters under compression. Finally, we explain the ejection of particles of a few eV as coming from the very low electrical conductivity of silica: under electronic irradiation, charges accumulate at its surface and accelerate the charged vaporized particles by Coulombian repulsions
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Coux, González Patricia De. "Intégration de films épitaxiés de CoFe2O4 ferrimagnétiques sur silicium." Toulouse 3, 2013. http://thesesups.ups-tlse.fr/2273/.
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L'intégration de couches minces de CoFe2O4, ferromagnétique et isolant électrique à température ambiante, sur silicium pourrait être utilisée en tant que barrière tunnel dans un dispositif de filtre à spin, comme alternative à l'injection utilisant des électrodes ferromagnétiques et des barrières tunnel passives. L'instabilité thermodynamique entre CoFe2O4 et Si impose l'utilisation d'une couche tampon pour son intégration. L'exigeant défi est donc de fabriquer des bicouches épitaxiées et ultrafines afin de préserver le ferromagnétisme et le transport par effet tunnel. Nous avons adopté une stratégie de recherche en parallèle considérant différents candidats pour la couche tampon pour déposer des couches de CoFe2O4 par dépôt par laser pulsé (PLD). Nous avons utilisé des couches tampon de SrTiO3 épitaxiées sur Si(001) fabriquées par des collaborateurs de l'INL-Lyon. Une diffusion de Ti dans CoFe2O4, et une possible instabilité de l'interface SrTiO3/Si(001) ont été décelés. L'étude des mécanismes de croissance épitaxiale de l'yttrium stabilisé avec de la zircone (YSZ) sur Si(001) a permis de déterminer les limites de réduction d'épaisseur d'YSZ et de la couche interfaciale de SiOx par PLD monitorisé par RHEED. L'épaisseur de CFO/YSZ/SiOx résultante est excessive pour un dispositif de filtre à spin. Les buffers de Sc2O3 et Y2O3 sur Si(111), fournis par des collaborateurs de l'IHP-Frankfurt Oder présentent un grand désaccord paramétrique avec CoFe2O4, mais permettent sa croissance épitaxiale par domaines avec une magnétisation proche de celle du matériau massif. Y2O3 étant stable avec Si est très prometteurs pour la structure de filtre à spinThe integration of ferromagnetic and electrically insulating at room temperature CoFe2O4 thin films with silicon could be used as tunnel barrier in a spin filter device as an alternative to the injection using ferromagnetic electrodes and passive tunnel barriers. The thermodynamical instability between CoFe2O4 and Si imposes the use of a buffer layer for its epitaxial integration. The challenging goal is therefore fabricating ultrathin epitaxial CoFe2O4/buffer bilayers on silicon in order to preserve ferromagnetism and allow the tunnel transport. The followed strategy was based on investigating in parallel several buffer candidates to grow CoFe2O4 by pulsed laser deposition (PLD). We have used thick SrTiO3 buffers fabricated by collaborators at INL-Lyon, which is epitaxial and ferromagnetic. However, there is diffusion of Ti into CoFe2O4 and the SrTiO3/Si(001) interface could be unstable. The epitaxial growth mechanism of yttria-stabilized-zirconia (YSZ) was investigated to determine the limits reducing the YSZ thickness and the interfacial layer by reflection high energy electron diffraction (RHEED) assisted PLD. The total thickness of CFO/YSZ/SiOx is excessive for a tunnel device. Sc2O3 and Y2O3 buffers on Si(111), provided by collaborators at IHP-Frankfurt Oder presents a huge lattice mismatch with CoFe2O4, but allows it epitaxial growth by domain matching epitaxy with a magnetization close to the bulk value. The absence of interfacial SiOx layer in the CoFe2O4/Y2O3/Si(111) sample indicates that Y2O3 is a very promising buffer layer and maybe convenient for the nanometric structure required in a spin filter
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Mathur, Shashank. "Croissance et structure à l'échelle atomique d'un nouveau matériau cristallin bidimensionnel à base de silicium et d'oxygène." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAY019/document.
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L'oxyde de silicium est un composé très largement abondant qui existe sous différentes phases, cristallines ou amorphes, qui se présentent sous la forme de structures poreuses ou de films minces. Il s'agit d'un diélectrique traditionnel pour la microélectronique et d'un support de choix pour des nanoparticules dans des systèmes catalytiques. Sa structure, amorphe ou tridimensionnelle et complexe, rend difficile la compréhension des propriétés jusqu'aux échelles les plus élémentaires. Les films utra-minces épitaxiés, parfois nommés « silice bidimensionelle » se prêtent au contraire à des caractérisation fines de la structure et des propriétés.Cette thèse avait pour objectif de préparer une telle phase d'oxide de silicium. A l'aide de sondes de sciences des surfaces, la microscopie à effet tunnel (STM), la diffraction d'électrons rapides en réflexion (RHEED), dont les analyses ont été confrontées aux résultats de calculs en théorie de la fonctionnelle de la densité (DFT), la structure de cette phase à pu être résolue jusqu'à l'échelle atomique. Nous avons mis en évidence l'arrangement hexagonal de tétraèdres de [SiO4], chimisorbés sur la surface (0001) du ruthenium en des sites spécifiques. Une phase d'oxygène diluée, reconstruite sur le Ru(0001), a été observée, qui coexiste avec l'oxide de silicium.La croissance de l'oxyde de silicium, a également été étudiée, par un suivi in operando, en temps réel pendant la croissance, par RHEED. Une évolution marquée de taille de domaines et/ou de l'accumulation et de la relaxation de déformations a été observée alors que l'oxyde de silicium crystallise. Un mécanisme de croissance a été proposé sur la base de ces observations, selon lequel les espèces chimiques à la surface se réorganisent par des déplacements latéraux élémentaires. Ce mécanisme s'accompagne de la formation, inévitable, de lignes de défauts uni-dimensionnelles, dont la structure a été déterminée à l'échelle atomique par STMSilicon oxide is a widely abundant compound existing in various forms from amorphous to crystalline, bulk to porous and thin films. It is a common dielectric in microelectronics and widely used host for nanoparticles in heterogenous catalysis. Its amorphous nature and the ill-defined complex three dimensional structure is a hurdle to the understanding of its properties down to the smallest scales. Resorting to epitaxially grown ultra-thin phase (also called a two-dimensional material) can help overcome these issues and provide clear-cut information regarding the structure and properties of the material.In this thesis, studies were aimed at growing this promising novel phase of silicon oxide. Using surface science tools, including scanning tunelling microscopy (STM) and reflection high energy electron diffraction (RHEED) supported by density functional theory calculations, the atomic structure was resolved to high resolution. The monolayer was found to have a hexagonal arrangement of the [SiO4] tetrahedra chemisorbed on the surface of Ru(0001) into specific sites. This lattice of monolayer silicon oxide was also found to coexist with an oxygen reconstruction of the bare Ru(0001) inside each silicon oxide cell.The growth of this monolayer was monitored in real-time by in operando RHEED studies. These experiments provided with insights the domain size evolution and the build up/release of strain field during the growth that. Based on the experimental observations, a growth mechanism leading to the formation of monolayer silicon oxide could be proposed in terms of geometrical translations of the atomic species on the surface of Ru(0001) support. This mechanism results in unavoidable formation of one-dimensional line-defects that were precisely resolved by the STM
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Garbi, Ahmed. "Développement de nouveaux procédés d’isolation électrique par anodisation localisée du silicium." Thesis, Lyon, INSA, 2011. http://www.theses.fr/2011ISAL0072/document.
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L’industrie microélectronique est régie depuis plusieurs années par la loi de miniaturisation. En particulier, en technologie CMOS, les procédés de fabrication de l’oxyde permettant l’isolation électrique entre les transistors nécessitent sans cesse d’être améliorés pour répondre aux défis de cette loi. Ainsi, on est passé du procédé d’isolation par oxydation localisée de silicium (LOCOS) au procédé d’isolation par tranchées (STI). Cependant, ce dernier a montré pour les technologies en développement des limitations liées au remplissage non parfait par la silice de tranchées de moins en moins larges (Voiding) et au ‘‘surpolissage’’ des zones les plus larges (Dishing). Le procédé FIPOS (full isolation by porous oxidation of silicon) a été donc proposé comme solution alternative. Il est basé sur la formation sélective et localisée du silicium poreux qui est transformé ensuite en silice par un recuit oxydant. Cette piste prometteuse a constitué le point de départ de ce travail. Dans ce contexte, la thèse s’est focalisée sur deux axes principaux qui concernaient d’une part la maîtrise du procédé d’anodisation électrochimique pour la formation du silicium poreux et d’autre part l’optimisation du procédé d’oxydation. Dans une première partie de notre travail, l’analyse des caractéristiques courant-tension I-V menée sur le silicium durant son anodisation électrochimique a permis de montrer que la formation du silicium poreux dépend fortement de la concentration en dopants. Cette propriété nous a permis de développer une technique simple d’extraction du profil de dopage dans le silicium de type p par voie électrochimique. On a montré que la résolution en profondeur de cette technique est liée au niveau du dopage et s’approche de celle du SIMS (spectroscopie de masse d'ions secondaires) pour les fortes concentrations avec une valeur estimée à 60 nm/décade. Dans une deuxième partie, nous avons mis en évidence la formation localisée du silicium poreux oxydé. En effet, un choix judicieux du potentiel d’anodisation permet de rendre poreux sélectivement des régions fortement dopées implantées sur un substrat de silicium faiblement dopé. Ces régions sont ensuite transformées en oxyde par un recuit oxydant. Par ailleurs, les conditions optimales des processus d’oxydation et d’anodisation permettant d’obtenir un oxyde final de bonne qualité diélectrique sont analyséesThe microelectronic industry is still ruled up to now by the law of miniaturization or scaling. In particular, in CMOS (complementary metal-oxide semiconductor) technology, the oxide allowing electric isolation between p- and n-MOS transistors has also been scaled down and has then exhibited different technological processes going from LOCOS (local oxidation of silicon) to STI (shallow trench isolation) and arriving to FIPOS (full isolation by porous oxidation of silicon). The latter seems to be the most promising alternative solution that can overcome actual limitations of voiding and dishing encountered in the STI process. The approach, which is based on selective formation of porous silicon and its easy transformation to silicon dioxide, has aroused our motivation to be well studied. In this context, the PhD project has first focused on the understanding of electrochemical porous silicon formation, and then on the study of porous silicon oxidation. In a first part of our work, we emphasize the dependence of porous silicon formation with the silicon doping concentration through the investigation of current-voltage I-V characteristics measured on p- and n-type silicon electrodes during electrochemical anodization. Taking advantage of this dependence, we have developed a very simple electrochemical method allowing an accurate determination of doping profiles in p-type silicon. It has been shown that the depth resolution of the technique is readily linked to the doping level and it approaches that of the secondary ion mass spectroscopy (SIMS) analysis for high doping concentrations with an estimated value of 60 nm/decade. In a second step, we highlight the selective formation of oxidized porous silicon. In fact, with a correct choice of the applied potential during anodization, only highly doped regions implanted on a lightly doped silicon wafer are preferentially turned into porous silicon and subsequently oxidized. Furthermore, we give the optimum conditions for oxidation and anodization processes which result in an insulating oxide of reliable dielectric properties
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Bruhat, Elise. "Développement de cellules photovoltaïques silicium à homojonction industrialisables à contacts passivés." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI128.
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Afin de favoriser le déploiement des énergies renouvelables, le développement de cellules solaires moins chères mais aussi plus performantes reste un enjeu pour rendre l’électricité photovoltaïque encore plus attractive. Si les technologies des cellules solaires à base de silicium à homojonction dominent le marché mondial, les performances de ces structures peuvent encore être améliorées. En effet, le contact direct entre la grille métallique et les zones fortement surdopées est source de pertes par recombinaisons des porteurs de charges. L’émergence de de nouvelles structures de cellules émergent à contacts passivés permet des solutions alternatives face à cette limitation. Ces structures visent à délocaliser la prise de contact grâce à l’introduction de couches passivantes entre le substrat de silicium cristallin et la grille de métallisation, diminuant ainsi drastiquement les phénomènes de recombinaisons au sein des dispositifs. La technologie de contacts passivés la plus connue reste celle des cellules à hétérojonction de silicium a-Si:H/c-Si. Cette technologie mature reste pour l’instant limitée car elle représente un nouveau standard industriel mais aussi car elle n’est pas compatible avec les procédés utilisant des températures excédant 250°C. De plus, l’utilisation d’indium, matériau cher et dont la ressource est limitée, dans les couches d’Oxyde Transparent Conducteur (OTC) peut représenter un frein à l’industrialisation de masse du procédé. Il est alors nécessaire de développer de nouvelles technologies de contacts passivés, compatibles avec des procédés à haute température (supérieures à 800°C), et donc intégrables dans une ligne de production existante. Des approches utilisant des OTC en combinaison avec des couches ultraminces d’oxydes, des empilements diélectriques, et des jonctions poly-silicium sur oxyde ont été investiguées afin d’améliorer les performances des cellules à homojonction. Les couches intermédiaires d’OTC développées permettent potentiellement de diminuer les pertes résistives et et celles par recombinaison au niveau des contacts. Ces travaux de thèse se sont ainsi focalisés sur le développement de couches d’oxyde de zinc dopé à l’aluminium (AZO) par pulvérisation cathodique (PC) et Atomic Layer Deposition (ALD) pour les cellules solaires à contact passivés. Ces couches, utilisées seules ou en combinaison avec des matériaux diélectriques, ont été intégrées et testées sur des dispositifs photovoltaïques fonctionnelsFor the deployment of renewable energies, the development of cheaper and more efficient solar cells remains an issue to make photovoltaic electricity even more attractive. While homojunction-based silicon solar cell technologies dominate the global market, the performances of these structures can be further improved. Indeed, the direct contact between the metal grid and the highly doped junction is a source of recombination losses. To overcome these limitations, new structures are emerging such as silicon-based passivated contacts solar cells. These structures aim at integrating of passivating layers between the crystalline silicon substrate and the metal grid, thus drastically reducing the recombination phenomena within the devices. Silicon heterojunction (a-Si:H/c-Si) cells remain the most well-known passivated contact technology. Nevertheless, this mature technology is still limited by its fabrication process which is far from the industrial standard, and is hardly compatible with temperatures exceeding 250 ° C. In addition, the use of expensive and potentially toxic indium in the Transparent Conductive Oxide (TCO) layers has restrained up to now the expansion towards mass industrialization of the process. Thus, it is necessary to develop new passivated contacts technologies compatible with high temperature (above 800°C), implementable in a standard production line. This study explores new paths for passivating contact technologies thanks to ultrathin layers of oxides or dielectrics/TCO stacks deposited on silicon homojunctions as well as poly-silicon on thin oxide junctions. In order to limit the resistive losses and potentially limit recombination losses in the contacted areas, intermediate TCO layers have been developed. In this perspective, this works aims at investigating the development of Aluminum Zinc Oxide (AZO) layers by both Magnetron Sputtering (MS) and Atomic Layer Deposition (ALD) for passivated contact solar cells. These layers, also used in combination with dielectric materials have been integrated and then tested in photovoltaic devices
Book chapters on the topic "Oxide silicium"
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Kaneko, Junichi, Makoto Sugamata, and H. Akiyama. "Mechanically Alloyed P/M Composites of Al-Mg-Silicide and Al-Mg-Oxide Systems." In THERMEC 2006, 854–59. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-428-6.854.
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Ayalew, Dereje, and Bekele Abebe. "Mineralogy of Peralkaline Silicic Volcanics: Information from Kone Volcano, Ethiopian Rift Valley." In Mineralogy. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.102677.
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The presented paper described in detail the mineralogy of silicic peralkaline eruptives from Kone volcano within the Ethiopian rift system, which is formed predominantly by rhyolite with some small occurrence of trachyte. The majority of eruptive rocks in the Kone volcanic area are phenocryst-poor. The studied rocks contain alkali feldspars (anorthoclase and sanidine), quartz, clinopyroxene (hedenbergite), aenigmatite and olivine (fayalite), accompanied by rare Fe-To oxides (ilmenite) and apatite. All these minerals are described in detail. These data are very interesting for all researchers, who study similar eruptive rocks.
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LAYER, E. H. "Nitride, Silicide and Oxide Evaporated Films for the Electronic Industry." In Vacuum Technology Transactions, 210–14. Elsevier, 2013. http://dx.doi.org/10.1016/b978-1-4831-9852-1.50046-3.
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Gilpérez, J. M., A. Climent, J. M. Martínez-Duart, and J. Perrière. "QUANTITATIVE BBS ANALYSIS OF SILICIDES AND SILICIDE OXIDES USING BUMP." In EPM ’89: 3rd International Conference on Energy Pulse and Particle Beam Modification of Materials, September 4.–8. 1989, Dresden, GDR, 268–70. De Gruyter, 1989. http://dx.doi.org/10.1515/9783112575666-060.
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Liu, Chin-Hung, Te-Chien Hou, and Yu-Lun Chueh. "Synthesis and Characterization of One-Dimensional Functional Metal Oxide and Metallic Silicide Nanostructures." In Mass Transport of Nanocarriers, 767–839. Pan Stanford Publishing, 2012. http://dx.doi.org/10.1201/b12528-22.
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"Synthesis and Characterization of One-Dimensional Functional Metal Oxide and Metallic Silicide Nanostructures." In Handbook of Innovative Nanomaterials, 793–866. Jenny Stanford Publishing, 2012. http://dx.doi.org/10.1201/b12707-43.
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Pilco, Richard, and Sean McCann. "Chapter 22: Gold Deposits of the Yanacocha District, Cajamarca, Peru." In Geology of the World’s Major Gold Deposits and Provinces, 451–65. Society of Economic Geologists, 2020. http://dx.doi.org/10.5382/sp.23.22.
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Abstract The Yanacocha district of northern Peru has produced >37 million ounces (Moz) Au since production commenced in 1993. Recognized as one of the world’s most prolific high-sulfidation epithermal gold districts, its discovery was made over a four-year period (1984–1988) through a joint venture alliance operated by Newmont Corporation. Over the past 30 years the geologic understanding of the district has been enhanced by research and documentation by many academic and Newmont geoscientists. The gold deposits are hosted within Tertiary volcanic rocks consisting of pyroclastic sequences cut by several generations of breccias and intrusions, all of which have undergone silicic and advanced argillic alteration. A dominant NE-trending structural corridor bounds all deposits in the district, and local northwest fault intersections with this trend are complimentary controls on mineralization. There are 12 major deposits discovered and exploited at Yanacocha. The largest, Cerro Yanacocha, has produced >17.5 Moz Au, whereas the newest deposit to be delineated, Antonio, has a >1.0 Moz resource. The depletion of shallow, supergene-oxidized deposits has necessitated the current underground development to exploit deeper sulfide deposits. Significant potential remains within the Yanacocha district in both oxide and sulfide deposits, and ongoing exploration efforts, are leveraging learnings from mined deposits and advances in exploration technologies and tools to extend the mine life.
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Marmier, N., and C. Hurel. "Influence of dissolved silicic acid on the sorption of cations on oxides." In Water-Rock Interaction. Taylor & Francis, 2007. http://dx.doi.org/10.1201/noe0415451369.ch263.
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Thomas, Fabien, and Armand Masion. "27Al NMR Study of the Hydrolysis and Condensation of Organically Complexed Aluminum." In Nuclear Magnetic Resonance Spectroscopy in Environment Chemistry. Oxford University Press, 1997. http://dx.doi.org/10.1093/oso/9780195097511.003.0015.
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Aluminum is the most abundant metal of the Earth’s crust, of which it represents approximately 8%, ranking after oxygen and silicon. It exists mainly as oxides. In terrestrial environments, aluminum commonly exists as secondary (authigenic) hydroxide or aluminosilicate minerals, mainly clays. These minerals are highly insoluble at neutral pH. However, aluminum occurs in detectable amounts in natural waters, due to leaching of the soil minerals in acidic conditions. Soil acidity may have a natural origin, such as an acidic (silicic) mother rock, melted snow, dissolved carbonic acid, or biologically generated organic acids. During the past two decades, it has been demonstrated that one of the major origins of increased aluminum mobilization and transport in forested soils is introduction of strong acid through atmospheric sulfur and nitrogen deposition. It has also been shown that aqueous aluminum is the biogeochemical link between atmospheric pollution and damage caused to tree roots and aquatic organisms such as plankton, crustaceans, insects, and fish. Biological studies have shown that the different aluminum species exhibit various toxicities: the most toxic are the monomeric and the polynuclear species; complexation with organic acids results in low toxicity. The significance of aluminum to human health has long been regarded as negligible. There is a possible link between high-level aluminum contamination by renal dialysis or hemodialysis, and neurodegenerative health disorders such as Parkinson’s or Alzheimer’s diseases, but the part played by aluminum is not clear. However, since aluminum salts are used on an industrial level as coagulants and flocculants in water treatment, the aluminum concentration and speciation in drinking water deserve careful monitoring. Because of the specific toxicity of the aluminum species, there has been considerable concern in the past two decades over the speciation of aqueous aluminum present in soils and aquatic systems. To this end, several techniques have been developed in order to partition the aluminum species. The most common among them are chromatographic separation and categorization methods such as timed ferron reaction, and computational methods derived from thermodynamic equilibrium constants. However, significant discrepancies between the results have been noticed, and attributed to the dramatic interference of organic and inorganic anions in the Al fractionation.
Conference papers on the topic "Oxide silicium"
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Novak, Mark D., and Carlos G. Levi. "Oxidation and Volatilization of Silicide Coatings for Refractory Niobium Alloys." In ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-42908.
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Degradation mechanisms relevant to hypersonic environments have been investigated for silicide-coated niobium alloys. To assess the suitability of silicide coatings for possible leading edge, scramjet combustor, and vehicle acreage applications, tests were conducted over a range of oxygen and water vapor partial pressures. X-ray diffraction was used to characterize the composition of oxide phases. Chemical compositions of both the coatings and resulting oxides have been examined using energy dispersive x-ray analysis. Partial pressures of oxygen and water vapor have been found to influence the oxide composition, which may include silica, chromia, iron niobate, and chromium niobate phases. The formation of volatile oxide and hydroxide species also affects oxidation behavior and coating performance. Thermodynamic models of oxidation and volatilization are used to interpret experimental results.
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Rai, Raghaw, James Conner, Sharon Murphy, and Swaminathan Subramanian. "Challenges in Evaluating Thickness, Phase, and Strain in Semiconductor Devices Using High Resolution Transmission Electron Microscopy." In ISTFA 2006. ASM International, 2006. http://dx.doi.org/10.31399/asm.cp.istfa2006p0343.
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Abstract The aggressive scaling of metal oxide semiconductor field effect transistor (MOSFET) device features, including gate dielectrics, silicides, and strained Si channels, presents unique metrology and characterization challenges to control electrical properties such as reliability and leakage current. This paper describes challenges faced in measuring the thickness of thin gate oxides and interfacial layers found in high-K gate dielectrics, determining Ni silicide phase in devices, and characterizing strain in MOSFETs with SiGe stressors. From case studies, it has been observed that thin layers (gate oxide, high-K film thickness, and interfacial layer) can be measured using high-resolution transmission electron microscopy (HRTEM) with good accuracy but there are some challenges in the form of sample thickness, damage-free samples, and precise sectioning of the sample for site-specific specimens. Complementary information based on HRTEM, annular dark field, and image simulation should be used to check the accuracy of thin gate dielectric measurements.
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Matthews, M. M. "Case Study: Unique Stress Induced Gate Oxide Defects in a CMOS Analog/Digital Device Revealed by Backside Silicon Removal." In ISTFA 1996. ASM International, 1996. http://dx.doi.org/10.31399/asm.cp.istfa1996p0169.
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Abstract Stress induced pinholes, cracks, and 'craters' have been found in the gate oxide of a double level metal, single level poly CMOS device containing both analog and digital circuits. These defects have been found randomly across the die in active gate regions, and were found in a line parallel to the gate width. These defects were hidden beneath the polysilicon, and were virtually undetectable electrically. The only electrical indication was a slight shift in the threshold voltage, still within specification limits. The polysilicon had a compressive layer of tungsten silicide (WSix) as a cap to lower the polysilicon resistivity and increase circuit speed. It was believed that polysilicon grains or WSix spikes were migrating into the gate oxide during the WSix annealing process. The defects were found in unstressed, untested parts, and in parts that passed all tests and stresses. Backside silicon removal showed defects in the gate oxide layer, and subsequent FIB sectioning revealed a WSix spike. Several techniques were employed to verify the gate oxide defects. Electrical and destructive physical analysis techniques will be presented in the paper.
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Robertson, S. J., K. B. Sprinkle, and M. B. Ruggles-Wrenn. "Testing Advanced SiC Fiber Tows at Elevated Temperature in Silicic Acid-Saturated Steam." In ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/gt2017-65247.
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Investigating stressed oxidation and scale crystallization kinetics of advanced SiC fibers at elevated temperature in steam is a challenging yet essential undertaking for the assessment of the effects of oxidation on mechanical properties of SiC-SiC ceramic matrix composites (CMCs). Moisture in the oxidizing environment is known to change oxidation rates, reduce scale viscosity and lower temperatures for scale crystallization. In order to study these phenomena, a facility for testing SiC fiber tows in creep at elevated temperatures in air, in steam and in steam saturated with silicic acid was developed. The newly constructed test facility was validated through creep testing of Hi-Nicalon™-S fibers at 800°C in steam saturated with silicic acid. Testing in saturated steam resulted in formation of a uniform oxide scale. Details of the test facility design, development and experimental validation are presented.
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Hua, Y. N., G. B. Ang, S. Redkar, Yogaspari, and Wilma Richter. "Studies on Chemical Methods to Expose Gate/Tunnel Oxide and Identification of Gate/Tunnel Oxide Defects in Wafer Fabrication." In ISTFA 2002. ASM International, 2002. http://dx.doi.org/10.31399/asm.cp.istfa2002p0695.
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Abstract In failure analysis of wafer fabrication, currently, three different types of chemical methods including 6:6:1 (Acetic Acid/HNO3/HF), NaOH and Choline are used in removing polysilicon (poly) layer and exposing the gate/tunnel oxide underneath. However, usage is limited due to their disadvantages. For example, 6:6:1 is a relatively fast etchant, but it is difficult to control the etch time and keep the oxide layer intact. Also, while using NaOH to remove poly and expose the silicon oxide, the solution needs to be heated. It is also difficult to etch a poly layer with a WSix or a CoSix silicide using NaOH. In this paper, we will discuss these 3 etchants in terms of their advantages and disadvantages. We will then introduce a new poly etchant, called HB91. HB91 is useful for removing poly to expose the gate/tunnel oxide for identification of related defects. HB91 is actually a mixture of two chemicals namely nitric acid (HNO3) and buffer oxide etchant (BOE) in a 9:1 ratio. The experimental results show that it is highly selective in poly removal with respect to the gate/tunnel oxide and is a suitable poly etchant especially for removing polysilicon with/without WSix and CoSix in the large capacitor structure. Application results of this poly etchant (HB91) will be presented.
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Lin, Hung-Sung, and Chun-Ming Chen. "An Application of a Nanoprobe Technique in the Characterization of Advanced SRAM Devices." In ISTFA 2008. ASM International, 2008. http://dx.doi.org/10.31399/asm.cp.istfa2008p0417.
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Abstract The importance of understanding mismatched behavior in SRAM devices has increased as the technology node has shrunk below 100nm. Using the nanoprobe technique [1-3], the MOS characteristics of failure bits in actual SRAM cells have been directly measured. After transistors that are failing were identified, the best approach for identifying nanoscale defects was determined. In this study, several types of nanoscale defects, such as offset spacer residue, salicide missing from the active area, doping missing from the channel, gate oxide defects, contact barrier layer residue, and severed poly-gate silicide were successfully discovered.
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Thu, Yee Mon, Khin Maung Latt, and Abdul Aziz Bin Mohamed. "Characterization of Titanium Silicide (TiSi[sub 2]) for Complementary Metal Oxide Semiconductor." In NEUTRON AND X-RAY SCATTERING IN ADVANCING MATERIALS RESEARCH: Proceedings of the International Conference on Neutron and X-Ray Scattering—2009. AIP, 2010. http://dx.doi.org/10.1063/1.3295615.
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Kashyap, Savita, Rahul Pandey, Jaya Madan, and Rajnish Sharma. "Silicide on Oxide Based Carrier Selective Front Contact for 24% Efficient PERC Solar Cell." In 2022 IEEE VLSI Device Circuit and System (VLSI DCS). IEEE, 2022. http://dx.doi.org/10.1109/vlsidcs53788.2022.9811447.
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Yamanaka, K., and K. Yamaguchi. "Effect of Irradiation Atmospheres on the Film Growth of Iron Oxide on Si Substrate by Ion Beam Sputter Deposition Method." In The 5th Asia-Pacific Conference on Semiconducting Silicides and Related Materials, 2019 (APAC-Silicide 2019). Japan Society of Applied Physics, 2020. http://dx.doi.org/10.7567/jjapcp.8.011201.
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Qin, Wentao, Dorai Iyer, Jim Morgan, Carroll Casteel, Robert Watkins, Rod Crowder, and Mike Thomason. "Surface Microstructure Evolution Upon Silicidation of Ni(Pt) and the Different Responses to Metal Etch." In ISTFA 2013. ASM International, 2013. http://dx.doi.org/10.31399/asm.cp.istfa2013p0138.
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Abstract Ni(5 at.%Pt ) films were silicided at a temperature below 400 °C and at 550 °C. The two silicidation temperatures had produced different responses to the subsequent metal etch. Catastrophic removal of the silicide was seen with the low silicidation temperature, while the desired etch selectivity was achieved with the high silicidation temperature. The surface microstructures developed were characterized with TEM and Auger depth profiling. The data correlate with both silicidation temperatures and ultimately the difference in the response to the metal etch. With the high silicidation temperature, there existed a thin Si-oxide film that was close to the surface and embedded with particles which contain metals. This thin film is expected to contribute significantly to the desired etch selectivity. The formation of this layer is interpreted thermodynamically.
Reports on the topic "Oxide silicium"
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farahani, A. A., and M. L. Corradini. Experimental studies of thermal and chemical interactions between oxide and silicide nuclear fuels with water. Office of Scientific and Technical Information (OSTI), September 1995. http://dx.doi.org/10.2172/115059.
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