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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Investigation of diffusion and solid state reactions on the nanoscale in silicon based systems of high industrial potential : experiments and simulations

Parditka, Bence 18 December 2013 (has links)
La première partie de mes résultats concerne les phénomènes de diffusion induits par des effets de contrainte. Nous avons étudié ces effets d’un point de vu théorique, afin de comprendre le rôle de la contrainte dans la diffusion. Les résultats montrent que l’effet de contrainte ne semble pas induire d’effet mesurable sur le coefficient cinétique à l’interface, cependant le taux de mélange semble diminuer. La seconde partie concerne des mesures expérimentales, par EXAFS et GIXRF utilisées sur des empilements Ta/a-Si/Ni/a-Si/Ta/substrat permettant de suivre la formation des phases ainsi que la croissance, à une température donnée, et ce jusqu’à la formation de la phase Ni2Si et au delà. La troisième partie concerne le système Cu-Si. Nous avons suivi les premiers stades de la formation de la phase Cu3Si, en utilisant les techniques XRD, APT, SNMS, ainsi qu’un profilomètre et une mesure de résistance quatre points sur différents échantillons réalisés par pulvérisation. Dans le cas de l’empilement Cu/a-Si/substrat, la formation de phases a suivi une cinétique linéaire. Nous avons notamment mis en évidence la formation très rapide d’une phase qui apparait directement après le premier recuit très court, démontrant ainsi le rôle déterminant de la préparation des échantillons dans l’étude des processus de formation de phases. La quatrième partie s’intéresse au silicène : cette structure bidimensionnelle de silicium dite en « nid d’abeilles », réalisée sur un substrat d’argent et qui présente de grandes similitudes avec le graphène. En utilisant de façon complémentaire les techniques AES-LEED-STM, nous avons déterminé la limite de solubilité du silicium dans l’argent. / Diffusion and related solid state reaction phenomena have been studied in four different material couples. The first section of the results concerned the diffusion related stress effects. We analyzed the question theoretically, for planar model geometry, to find the role of stress in diffusion. We obtained that stress effects do not have any measurable effects on the kinetic coefficient of the interface shift. However, the intermixing rate decreases. The second section we performed EXAFS and GIXRF experiments on sandwich structured Ta/a- Si/Ni/a-Si/Ta/substrate samples and followed the phase formation and growth at a given temperature at which the Ni2Si phase has formed and continued to grow. The third section we obtained in the Cu-Si system. We followed the early stages of phase formation of the Cu3Si phase under different circumstances. We performed XRD, APT, SNMS, profilometer and 4 wire resistance measurements on sputtering deposited samples. We found that in case of the Cu/a-Si/substrate samples the phase formation was followed by a linear kinetics. Secondly, prior to the linear phase growth, we observed an extremely fast phase formation that appeared immediately after the very first and shortest annealing, which showed that the preparation sequence of the sample is a crucial point in phase formation processes. The fourth section deals with the silicene. It is the honeycomb structured formation of Si atoms with properties similar to graphene. We investigated the dissolution of Si into Ag. We performed a combination of AES, LEED, STM measurements. We determined the dissolution limit of Si in Ag from data obtained from the AES measurements.
2

Kirkendall Effect on the Nanoscale

Cserháti, C., Langer, G., Parditka, B., Csik, A., Iguchi, Y., Czigány, Zs., Erdélyi, Z. 13 September 2018 (has links)
Kirkendall effect has been studied experimentally as well as theoretically for decades already. There are theoretical indications, that the Kirkendall effect must operate from the beginning of the diffusion process but there are practically no measurements on this short time and length scale. For that reason, diffusion on the nanometer scale was investigated experimentally in different binary systems in thin film geometry. We followed the diffusion process as well as the Kirkendall effect by different methods (TEM, SNMS and synchrotron X-ray waveguide technique). Investigations were performed in systems with complete solubility (Bi-Sb, Cu-Ni, Bi-Sb) as well as in systems forming intermetallic phase (Fe-Sb, Fe- Pd). It was found that with these methods the Kirkendall shift can be well followed on the nano-scale. In Fe-Sb system even the bifurcation of the Kirkendall plane was observed.
3

SIMSおよびレーザSNMSによる半導体表面分析の高精度定量化に関する研究

東, 康弘 23 September 2016 (has links)
京都大学 / 0048 / 新制・論文博士 / 博士(工学) / 乙第13053号 / 論工博第4146号 / 新制||工||1657(附属図書館) / 33143 / (主査)教授 河合 潤, 教授 酒井 明, 准教授 松尾 二郎 / 学位規則第4条第2項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

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