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L'intégration du métal dans les nœuds technologiques sub-20 nm requiert une conformité supérieure à celle permise par la PVD. Les techniques de CVD, plus spécifiquement la MOCVD et l'ALD, ont été identifiées comme les meilleures solutions pour le dépôt de métal. Pour une application de métal de grille, les alliages carbo-nitrurés de titane et tantale sont considérés comme les plus prometteurs. Dans ce travail une revue détaillée des mécanismes de dépôt par MOCVD et ALD, ainsi que sur l'influence du plasma sur les matériaux déposés est réalisée. Dans un premier temps, les fenêtres de procédés possibles pour un ajustement des propriétés des métaux sont inspectées attentivement. L'accent est mis sur l'impact du plasma sur le métal et sur les mécanismes réactionnels inhérents grâce à une caractérisation poussée du plasma. Par la suite, l'intégration de ces métaux est étudiée avec une analyse précise des interactions se déroulant aux interfaces. La corrélation entre les propriétés physico-chimiques et le comportement électrique des empilements métal/diélectrique à forte permittivité est soutenue par une analyse XPS. Finalement, le dopage aluminium de dépôts de TiN et TaN MOCVD est étudié pour l'obtention de grilles n-mos et p-mos. Par comparaison des propriétés et comportements du dopage aluminium de métaux déposés par PVD et MOCVD, des mécanismes de diffusion sont proposés afin d'expliquer le rôle de l'aluminium sur les variations observées. / For the sub-20 nm technological nodes metal conformity requirements are beyond the possibilities of the currently used PVD deposition technique. CVD techniques, more specifically MOCVD and ALD, are identified as the best techniques for metal deposition. For metal-gate application, titanium and tantalum carbo-nitrides alloys are considered as the most promising. In this work, a detailed review of MOCVD and ALD deposition mechanisms and plasma influence on the deposited material is carried out. First, process windows for successful tuning of the metal properties are examined. Plasma impact on the metal and the inherent reaction mechanisms are also highlighted with the help of plasma characterisation. Then great importance is given to the integration of these metals, by careful study of the interactions taking place at the interfaces. Correlations between physico-chemical properties and electrical behavior of the metal/high-k dielectric stack are introduced thanks to XPS characterisation. Finally, aluminium doping of MOCVD TiN and TaN is considered for n-mos and p-mos gate characteristics achievement. By comparison of the properties and behaviours of Al doped metals deposited by PVD and MOCVD, diffusion mechanisms are proposed to explain the role of Al in the observed changes.

Des matériaux composites à matrice de titane renforcée par des fibres continues de carbone ont été élaborés par un procédé basé sur la métallurgie des poudres et dont certaines facettes sont proches de techniques utilisées pour les céramiques et pour les matériaux composites à matrice polymère. La mise en oeuvre de ce procédé a été confrontée à diverses difficultés que des études partielles ont permis de surmonter : la préparation de poudres de titane particulièrement fines, le couplage entre ces poudres et les mèches de fibres de carbone, le déliantage, la consolidation et la densification de la matrice de titane sous pression et à haute température. Bien que la faisabilité du procédé ait été démontrée, l'utilisation de poudres de titane insuffisamment fines ne permet pas d'incorporer des fractions volumiques de fibres de plus d'une dizaine de pour-cent, ce qui limite considérablement l'effet de renforcement évalué par des essais de traction. En revanche, l'incorporation dans les mèches de poudres d'hydrure de titane ne dépassant pas quelques microns a permis d'atteindre des fractions volumiques de plus de 30%.

Ni/TiC metal matrix composites have been processed using the laser engineered net shaping (LENS) process. As nickel does not form an equilibrium carbide phase, addition of a strong carbide former in the form of titanium reinforces the nickel matrix resulting in a promising hybrid material for both surface engineering as well as high temperature structural applications. Changing the relative amounts of titanium and carbon in the nickel matrix, relatively low volume fraction of refined homogeneously distributed carbide precipitates, formation of in-situ carbide precipitates and the microstructural changes are investigated. The composites have been characterized in detail using x-ray diffraction, scanning electron microscopy (including energy dispersive spectroscopy (XEDS) mapping and electron backscatter diffraction (EBSD)), Auger electron spectroscopy, and transmission (including high resolution) electron microscopy. Both primary and eutectic titanium carbides, observed in this composite, exhibited the fcc-TiC structure (NaCl-type). Details of the orientation relationship between Ni and TiC have been studied using SEM-EBSD and high resolution TEM. The results of micro-hardness and tribology tests indicate that these composites have a relatively high hardness and a steady-state friction coefficient of ~0.5, both of which are improvements in comparison to LENS deposited pure Ni.

Adições de Ti-C e Cr refinam o grão em nanocompósitos de Nd-Fe-B, aumentando substancialmente o valor de seu campo coercivo Hc. Isto motivou a investigação do efeito da adição de Ti-C e Cr em nanocompósitos de Pr-Fe-B e em outros nanocompóstitos à base de Nd-Fe-B. Fitas metálicas das composições (Pr9,5Fe84,5B6)0,97-x(TiC)0,03Crx (x = 0; 0,0025; 0,005; 0,0075; 0,01) e (Nd9,5Fe84,5B6)0,97-x (TiC)0,03Crx (x = 0,005; 0,01) foram produzidas por resfriamento rápido. Medidas de magnetização em campos magnéticos de até 90 kOe mostraram que os materiais contendo Cr possuem Hc substancialmente maior do que os demais sem. Para um nanocompósito de Pr com 1% Cr, o campo coercivo obtido foi Hc = 12,5 kOe, enquanto que para um nanocompósito de Pr com 0% Cr obtivemos um Hc = 5,1 kOe. O produto energético máximo da amostra com 1% Cr foi de, aproximadamente, 13,6 MGOe, valor este limitado pela remanência. Uma análise do difratograma de raios X mostrou que as fitas à base de Pr-Fe-B com 1%Cr consistem basicamente de uma fase Pr2Fe14B dura e uma fase α-Fe mole. Uma espectroscopia Mössbauer foi realizada em 300 K e mostrou uma redução dos campos hiperfinos devido à adição do Cr. Também foi realizada uma microscopia eletrônica de transmissão na amostra Pr-Fe-B com 1% Cr e os resultados mostraram que o nanocompósito possui um tamanho de grão maior do que o material sem Cr, sendo que a microestrutura majoritária são de grãos constituídos de α-Fe, de tamanho médio de 100 nm, imersos numa matriz de Pr2Fe14B. / Submitted by Marcelo Teixeira (mvteixeira@ucs.br) on 2014-05-30T15:59:14Z No. of bitstreams: 1 Dissertacao Vinicius Cappellano de Franco.pdf: 2554552 bytes, checksum: ca6455aec67ec4bd99efc6bdb3497dc6 (MD5) / Made available in DSpace on 2014-05-30T15:59:14Z (GMT). No. of bitstreams: 1 Dissertacao Vinicius Cappellano de Franco.pdf: 2554552 bytes, checksum: ca6455aec67ec4bd99efc6bdb3497dc6 (MD5) / The addition of both Ti and Cr-C refine the grains in nanocomposites of Nd-Fe-B, increasing substantially the coercive field Hc . This motived our investigation of the effect of the addition of Ti-C and Cr to nanocomposites of Pr-Fe-B and Nd-Fe-B. Ribbons compositions (Pr9,5Fe84,5B6)0,97-x(TiC)0,03Crx (x = 0; 0,0025; 0,005; 0,0075; 0,01) and (Nd9,5Fe84,5B6)0,97-x (TiC)0,03Crx (x = 0,005; 0,01) were produced by melt-spinning. Magnetization measures in fields up to 90 kOe showed that materials containing Cr have substantially higher Hc than the other materials without Cr. For a Pr nanocomposites with 1% Cr, the coercive field Hc was 12.5 kOe, while for a Pr nanocomposites with 0% Cr, Hc = 5.1 kOe. For the sample with 1% Cr, the maximum energy product was approximately 13.6 MGOe, a value limited by the remanence. The X-ray diffractogram analysis showed that the ribbons based on Pr-Fe-B with 1% Cr consist basically of a Pr2Fe14B hard phase and an α-Fe soft phase. Mössbauer spectroscopy was performed at 300 K and showed a reduction of the hyperfine field due to the addition of Cr. Transmission electronic microscopy of the Pr-Fe-B sample with 1% Cr showed that the nanocomposites have a grain size larger than the material without Cr, the microstructure consisting of α Fe grains, with an average size of 100 nm, in a matrix of Pr2Fe14B.

Adições de Ti-C e Cr refinam o grão em nanocompósitos de Nd-Fe-B, aumentando substancialmente o valor de seu campo coercivo Hc. Isto motivou a investigação do efeito da adição de Ti-C e Cr em nanocompósitos de Pr-Fe-B e em outros nanocompóstitos à base de Nd-Fe-B. Fitas metálicas das composições (Pr9,5Fe84,5B6)0,97-x(TiC)0,03Crx (x = 0; 0,0025; 0,005; 0,0075; 0,01) e (Nd9,5Fe84,5B6)0,97-x (TiC)0,03Crx (x = 0,005; 0,01) foram produzidas por resfriamento rápido. Medidas de magnetização em campos magnéticos de até 90 kOe mostraram que os materiais contendo Cr possuem Hc substancialmente maior do que os demais sem. Para um nanocompósito de Pr com 1% Cr, o campo coercivo obtido foi Hc = 12,5 kOe, enquanto que para um nanocompósito de Pr com 0% Cr obtivemos um Hc = 5,1 kOe. O produto energético máximo da amostra com 1% Cr foi de, aproximadamente, 13,6 MGOe, valor este limitado pela remanência. Uma análise do difratograma de raios X mostrou que as fitas à base de Pr-Fe-B com 1%Cr consistem basicamente de uma fase Pr2Fe14B dura e uma fase α-Fe mole. Uma espectroscopia Mössbauer foi realizada em 300 K e mostrou uma redução dos campos hiperfinos devido à adição do Cr. Também foi realizada uma microscopia eletrônica de transmissão na amostra Pr-Fe-B com 1% Cr e os resultados mostraram que o nanocompósito possui um tamanho de grão maior do que o material sem Cr, sendo que a microestrutura majoritária são de grãos constituídos de α-Fe, de tamanho médio de 100 nm, imersos numa matriz de Pr2Fe14B. / The addition of both Ti and Cr-C refine the grains in nanocomposites of Nd-Fe-B, increasing substantially the coercive field Hc . This motived our investigation of the effect of the addition of Ti-C and Cr to nanocomposites of Pr-Fe-B and Nd-Fe-B. Ribbons compositions (Pr9,5Fe84,5B6)0,97-x(TiC)0,03Crx (x = 0; 0,0025; 0,005; 0,0075; 0,01) and (Nd9,5Fe84,5B6)0,97-x (TiC)0,03Crx (x = 0,005; 0,01) were produced by melt-spinning. Magnetization measures in fields up to 90 kOe showed that materials containing Cr have substantially higher Hc than the other materials without Cr. For a Pr nanocomposites with 1% Cr, the coercive field Hc was 12.5 kOe, while for a Pr nanocomposites with 0% Cr, Hc = 5.1 kOe. For the sample with 1% Cr, the maximum energy product was approximately 13.6 MGOe, a value limited by the remanence. The X-ray diffractogram analysis showed that the ribbons based on Pr-Fe-B with 1% Cr consist basically of a Pr2Fe14B hard phase and an α-Fe soft phase. Mössbauer spectroscopy was performed at 300 K and showed a reduction of the hyperfine field due to the addition of Cr. Transmission electronic microscopy of the Pr-Fe-B sample with 1% Cr showed that the nanocomposites have a grain size larger than the material without Cr, the microstructure consisting of α Fe grains, with an average size of 100 nm, in a matrix of Pr2Fe14B.