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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

Predictive Process Design Kits for the 7 nm and 5 nm Technology Nodes

January 2019 (has links)
abstract: Recent years have seen fin field effect transistors (finFETs) dominate modern complementary metal oxide semiconductor (CMOS) processes, [1][2], e.g., at the sub 20 nm technology nodes, as they alleviate short channel effects, provide lower leakage, and enable some continued VDD scaling. However, a realistic finFET based predictive process design kit (PDK) that supports investigation into both circuit and physical design, encompassing all aspects of digital design, for academic use has been unavailable. While the finFET based FreePDK15 was supplemented with a standard cell library, it lacked full physical verification (LVS) and parasitic extraction at the time [3][4]. Consequently, the only available sub 45 nm educational PDKs are the planar CMOS based Synopsys 32/28 nm and FreePDK45 (45 nm PDK) [5][6]. The cell libraries available for those processes are not realistic since they use large cell heights, in contrast to recent industry trends. Additionally, the SRAM rules and cells provided by these PDKs are not realistic. Because finFETs have a 3D structure, which affects transistor density, using planar libraries scaled to sub 22 nm dimensions for research is likely to give poor accuracy. Commercial libraries and PDKs, especially for advanced nodes, are often difficult to obtain for academic use, and access to the actual physical layouts is even more restricted. Furthermore, the necessary non disclosure agreements (NDAs) are un manageable for large university classes and the plethora of design rules can distract from the key points. NDAs also make it difficult for the publication of physical design as these may disclose proprietary design rules and structures. This work focuses on the development of realistic PDKs for academic use that overcome these limitations. These PDKs, developed for the N7 and N5 nodes, even before 7 nm and 5 nm processes were available in industry, are thus predictive. The predictions have been based on publications of the continually improving lithography, as well as estimates of what would be available at N7 and N5. For the most part, these assumptions have been accurate with regards to N7, except for the expectation that extreme ultraviolet (EUV) lithography would be widely available, which has turned out to be optimistic. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2019
2

Investigating the characterisation and stability of polyamide 6,6 in heritage artefacts

Richardson, Emma January 2009 (has links)
Near‐infrared reflectance spectroscopy (NIR) is investigated as a method of non‐invasive, in situ analysis of contemporary textile material. Besides providing spectral signatures, the advantages of NIR include the non‐contact nature of the reflectance technique and the use of a remote, flexible probe. A spectral database of well‐defined reference material has been collected. This was recorded using a standardised protocol taking into account the need to interrogate objects within a collection. The differentiation of silk and synthetic polyamide can pose particular problems for curators of historic textiles due to the similarities in their visual appearance. NIR spectroscopy coupled with multivariate analysis is investigated for the differentiation of the polyamide sub‐classes, found extensively within textile collections. Two multivariate methods of classification have been applied and it is shown that, with the appropriate spectral processing and calibration, both of these techniques are appropriate for sub‐class discrimination. Synthetic polyamides are frequently found in conjunction with natural organic materials, and are often exposed to the same pest treatments as natural polymers. In the event of an infestation there are a number of eradication measures possible, including the application of raised and lowered temperatures. However, these treatments take unaged aliphatic polyamides above, and well below, their glass transition temperature, respectively. For this reason the stability of new and aged polyamide textile material has been investigated. Polyamide 6,6 test material was tested ‘as received’ and in an artificially aged condition. Samples were subsequently subject to ‐30°C, room temperature or 58°C. In addition, samples were treated with and without the application of a load, enabling an assessment of risk if treated whilst hanging and supporting their own weight. Structural alterations were monitored using polarized and non‐polarized mid infrared spectroscopy, tensile testing and differential scanning calorimetry. In addition, dynamic mechanical thermal analysis creep experiments were carried out to supplement the information provided by the in situ creep tests. It is evident from the results that the thermal treatments have a significant effect on the behaviour and structure of the aged polyamide. The implication for in situ treatment of this material in collections is clear, and must therefore be approached with caution. Analysis of the experimental data suggest that the changes observed can be related to the degree of crystallinity produced by the changes in temperature and by the presence of stress during treatment.
3

Improvement of a fluorescence immunoassay with a compact diode-pumped solid state laser at 315 nm

Niederkrüger, Matthias, Salb, Christian, Beck, Michael, Hildebrandt, Niko, Löhmannsröben, Hans-Gerd, Marowsky, Gerd January 2006 (has links)
We demonstrate the improvement of fluorescence immunoassay (FIA) diagnostics in deploying a newly developed compact diode-pumped solid state (DPSS) laser with emission at 315 nm. The laser is based on the quasi-three-level transition in Nd:YAG at 946 nm. The pulsed operation is either realized by an active Q-switch using an electro-optical device or by introduction of a Cr<SUP>4+</SUP>:YAG saturable absorber as passive Q-switch element. By extra-cavity second harmonic generation in different nonlinear crystal media we obtained blue light at 473 nm. Subsequent mixing of the fundamental and the second harmonic in a β-barium-borate crystal provided pulsed emission at 315 nm with up to 20 μJ maximum pulse energy and 17 ns pulse duration. Substitution of a nitrogen laser in a FIA diagnostics system by the DPSS laser succeeded in considerable improvement of the detection limit. Despite significantly lower pulse energies (7 μJ DPSS laser versus 150 μJ nitrogen laser), in preliminary investigations the limit of detection was reduced by a factor of three for a typical FIA.
4

Organic materials development for advanced lithographic applications

Adams, Jacob Robert 2009 August 1900 (has links)
The microelectronics industry strives for continued reduction in feature sizes to allow increased computing speed and power. This calls for continuous development of new materials. During the shift to 157 nm photolithography, it was discovered that fluorinated materials were necessary to provide sufficient transparency. Material design and synthesis to incorporate fluorine bearing norbornane based materials through an alternate means of polymerization to those used in traditional lithographic materials will be presented. Step and Flash Imprint Lithography represents a low cost alternative to optical lithography for production of nanoscale features. Sub-20 nm features have been produced using commercial tools however the contact between the imprint template and resist formulation leaves the template prone to fouling. A new imprint resist designed to facilitate wafer reworking and template cleaning is presented. The small amount of power available from deep ultraviolet light sources necessitates the use of systems that behave in a catalytic manner that is referred to as gain. The use of small molecules for gain necessitates a reliance on diffusion through the resist film and results in image bias. A polymeric material that undergoes depropagation catalyzed by a single photochemical event and causes a solubility change due to this event represents a system that possesses gain while removing diffusion bias. Progress towards such a system is presented. / text
5

Roger Machado : a life in objects

Watson, Gemma January 2013 (has links)
This thesis is the micro-history of Roger Machado, who is best known as Leicester Herald for Edward IV, Edward V, and Richard III, and the senior herald, Richmond King of Arms, for Henry VII. Prior to this thesis, Machado has only been sparsely considered by scholars because he is elusive in the historical record. There is, in the College of Arms, his extant memorandum book, but otherwise, sources referring to him are few and far between. However, in the 1970s, Machado’s Southampton residence was excavated, which unearthed a rich artefact assemblage associated with his occupancy. This discovery has allowed for a fresh perspective on Machado’s life. This thesis, therefore, uses both documentary and archaeological sources to unlock the man from the records, and consequently, places a strong emphasis on the importance of interdisciplinary research. By pursuing a micro-historical approach that focusses on Machado’s engagement with objects, this thesis uses Machado as a window into the world in which he lived. Machado lived through the later years of the Wars of the Roses and through the entire reign of the Tudor dynasty’s first monarch, Henry VII. Therefore, his life is well placed to enable this thesis to consider broader themes. The first chapter discusses the micro-historical approach. The second chapter discusses how Machado, as a foreigner, came to work and live in England, how he came to join the exiled Henry Tudor, and examines the herald and Office of Arms in the fifteenth century. The third chapter considers the ceremonial role that Machado and the heralds played at the Yorkist and early Tudor courts. The fourth chapter considers Machado’s life and home in early Tudor Southampton, using the objects excavated from his house and others recorded in his extant inventory. The fifth chapter discusses how Machado would have used such objects in dining.
6

Einfluss der Einzelenergie mit angepasster Pulsdauer und –zahl auf die Verträglichkeit einer Epilation mittels flächig scannenden Diodenlasers (808 nm) im Achselbereich

Winkelmann, Anja 23 July 2015 (has links) (PDF)
Die vorliegende Studie untersucht mittels eines Diodenlaser (808 nm) zur axillären Epilation, inwieweit eine Reduktion der applizierten Einzelenergie mit angepasster Pulsdauer und repetitiver Pulszahl (Low-Fluence) eine Verträglichkeitssteigerung, bei gleichzeitigem Erhalt der Epilationseffektivität, wie er von traditionelle High-Fluence Applikationen bekannt ist, bewirken kann. Es wurden die Axillae von 21 Patienten des Hauttyps eins bis drei nach zwei unterschiedlichen Protokollen im vierwöchigen Intervall behandelt. Auf der linken Seite erfolgte die Therapie sechsmalig mittels Low-Fluence, wohingegen auf der rechten Seite eine Kombination von dreimalig Low-Fluence- und dreimalig High-Fluence-Modus appliziert wurde. Es konnte hinsichtlich der Effektivität kein statistisch signifikanter Unterschied zwischen beiden Behandlungsmethoden nachgewiesen werden. Die Reduktion zeigte sich konstant und lag am Ende der 24-monatigen Gesamtstudiendauer im Mittel bei 45%. Die Ergebnisse stellen sich damit schlechter dar, als bei konventionellen Studien im High-Fluence-Bereich oder anderen Low-Fluence-Konzepten. Als Ursache ist am ehesten eine unzureichende Einzelimpulsdauer und eine zu gering gewählte Pulswiederholungsanzahl zu sehen. Andererseits ergab sich eine deutliche Verträglichkeitssteigerung, vor allem hinsichtlich des Schmerzempfindens und im Auftreten von Pigmentierungsstörungen zu Gunsten der Low-Fluence-Therapie.
7

Caractérisation et contrôle industriel des contraintes locales en microélectronique : applications aux transistors de technologie 20 nm / Characterization and industrial control of local stress in microelectronics : applications to advanced transistors technology of 20 nm

Durand, Aurèle 29 November 2016 (has links)
De nombreuses techniques de caractérisation sont utilisées dans les industries de la microélectronique dans le but d’inspecter et analyser les circuits. Actuellement, la réduction des dimensions des transistors, l’implémentation d’alliage de silicium-germanium (SiGe) et l’ingénierie des déformations, nécessitent de développer une métrologie innovante des champs de déformations induits par les procédés de fabrication. Ces techniques non-destructives et rapides de caractérisation des déformations doivent être aussi capables d’analyser des nanostructures directement en ligne de production. Dans ce contexte, nous avons évalué les performances de la diffraction de rayons-X haute résolution (HRXRD) et de la spectroscopie Raman à mesurer des déformations, et nous avons proposé une méthodologie adaptée aux exigences de la métrologie.Les équipements industriels de HRXRD développés pour la métrologie, sont aptes à mesurer la déformation de couches nanométriques de SiGe, avec une grande sensibilité (< 10-4). Néanmoins, pour des structures complexes comme les transistors planaires, la complexité du champ de déformation requière la mesure et l’analyse approfondie de cartographies de l’espace réciproque (RSM). Nous avons alors montré l’intérêt et les performances des RSM pour la caractérisation des déformations dans des réseaux de transistors pMOS. Pour ce faire, une méthode inverse a été développée, consistant à simuler des RSM à partir d’une modélisation mécanique des champs de déformation. Différents modèles ont été explorés et un très bon accord entre les RSM mesurées et simulées est établi. Le champ des déformations extrait par cette méthode est corrélé avec succès à celui mesuré par la technique d’holographie électronique en champ sombre, démontrant ainsi l’analyse fine des champs des déformations de pMOS par HRXRD.La spectroscopie µ-Raman a aussi été identifiée comme étant une candidate prometteuse pour l’industrie, du fait de sa résolution spatiale sub-micrométrique et d’une grande sensibilité sur des structures nanométriques. Elle permet de déterminer de manière simultanée l’état de déformation et la composition moyenne d’un film de SiGe de quelques nanomètres d’épaisseur. Ainsi, la spectroscopie µ-Raman a alors permis de révéler que le procédé de condensation, critique pour la création du canal en SiGe contraint des transistors de technologie avancée, induit une inhomogénéité de composition en germanium dans le film de SiGe. Enfin, la résolution spatiale de la spectroscopie µ-Raman et de la spectroscopie Raman exaltée par effet de pointe (TERS) a été déterminée par comparaison de mesures avec des simulations. Ces résultats montrent les évolutions attendues pour répondre aux exigences de l’industrie de la microélectronique.Finalement, une méthodologie industrielle d’HRXRD permettant de suivre en ligne l’évolution du champ de déformation pendant les procédés de fabrication est développée. La méthode principale utilise une librairie de RSM simulées pour toute une série de structures avec des géométries, des compositions en germanium et des paramètres de déformation variables. Les RSM mesurées sont ensuite associées de manière sélective aux RSM simulées inclues dans la librairie, fournissant simplement et rapidement une géométrie et un champ des déformations comme données de sortie, paramètres pouvant être ajustés par des itérations ultérieures si nécessaire. Grâce au développement d’un logiciel (DeusX), qui traite et simule les RSM, l’ensemble de la procédure est capable de suivre, détecter et localiser automatiquement des variations faibles de déformation induites par les étapes de fabrication. L’ensemble des résultats démontrent que la procédure est compatible avec les exigences industrielles : rapidité, robustesse et simplicité. Ce travail est ainsi une avancée majeure vers l’utilisation des RSM pour le suivi industriel en ligne des déformations. / For many years, characterization techniques have been used in the microelectronic industry in order to probe and analyze integrated components. Nowadays the critical downscaling of transistors and implementation of new materials and methods, such as silicon-germanium (SiGe) and strain engineering, induce the necessity of developing innovative metrology in order to monitor the fabrication processes at each step. In this context, there is a need for non-destructive and fast strain characterization techniques, capable of in-line analysis of nano-structures. Within that framework, the capabilities of High Resolution X-Ray Diffraction (HRXRD) and Raman spectroscopy for strain measurements is evaluated and a methodology tailored to in-line metrology constraints is proposed.Industrial HRXRD equipment, developed for an in-line strain metrology have demonstrated their ability to measure strain in SiGe thin films of only a few nanometers thick, with a great sensitivity (< 10-4). Nonetheless, when it comes to advanced structures, such as planar transistors, the strain field complexity requires the measurement and the thorough analysis of Reciprocal Space Mappings (RSM). In this study, we demonstrate the interest and capability of RSM for the characterization of strained structures for gratings of pMOS transistors. A reverse method that consists in using a strain field model to reproduce the measured RSMs is used. The benefit of using different mechanical models is explored and a very good agreement between experimental and simulated RSM’s is established. Strain field extracted by this method is successfully correlated to the one measured by Dark-Field Electron Holography (DFEH) technique, emphasizing the capability of HRXRD for pMOS strain field investigation.Alongside, µ-Raman spectroscopy was also identified to be a promising candidate for the industry, due to a sub-micrometers spatial resolution and a low detection threshold. It enables to determine simultaneously the strain state and the average composition of SiGe thin films down to the nanometer scale. Thereby, µ-Raman reveals that a condensation process, critical to create a strained SiGe channel for advanced transistor technology, induces a germanium composition inhomogeneity in the SiGe thin films. To go further, the spatial resolution of µ-Raman and Tip-enhanced Raman Spectroscopy (TERS) techniques is investigated by comparing the measurements with simulations, highlighting that there is still some way to go before fulfilling the demands of the microelectronics industry.Finally, a HRXRD methodology is developed in order to follow the strain field evolution all along process steps in a manufacturing environment. The main method uses a large library computed for a bunch of structures with varying geometries, germanium content and strain parameters. Then the measured RSMs are selectively matched to the simulated RSMs within the library, providing in a simple and a quick way a close corresponding geometry and strain field as an output, which could then be refined by iteration if necessary. Thanks to a homemade software (DXtract), that processes and simulates the RSMs, the whole procedure is automated and is capable to follow, detect and localize even the small strain variations induced by the manufacturing steps. In addition, all the results demonstrate that the procedure is compatible with industrial constraints, meaning fast, robust and easy to operate. This work is therefore a major step towards the use of RSM for in-line monitoring, which is undoubtedly a relevant technique for industrial strain metrology.
8

Etudes théorique et expérimentale des performances des dispositifs FD SOI sub 32 nm / heoretical and experimental studies of FD SOI devices performances for sub 32 nm nodes

Ben Akkez, Imed 20 December 2012 (has links)
> Ce manuscrit présente une étude théorique et expérimentale effectuée sur des transistors MOSFET d’une> technologie avancée de type FD SOI (complètement déserté silicium sur isolant). Des mesures électriques> combinées avec des modélisations ont été effectuées dans le but d’apporter des explications sur des phénomènes> liés à réductions des dimensions des transistors. Ce travail de thèse donne une réponse partielle de l’impact de ces> aspects sur les paramètres électrique ainsi que les paramètres de transport." / This manuscript presents a theoretical and experimental study carried out on advanced technology the FD SOI MOSFETs (Fully Depleted Silicon On Insulator MOSFET’s). Electrical measurements combined with modeling were performed with an aim of bringing explanations of phenomena related to the dimension reduction in these structures. This work gives an answer of the impact of these aspects on the electrical parameters and on the carriers transport in the channel.
9

Conception et Etude de la Fiabilité des Amplificateurs de Puissance Fonctionnant aux Fréquences Millimétriques en Technologies CMOS Avancées

Quémerais, Thomas 06 October 2010 (has links) (PDF)
Avec l'émergence d'applications millimétriques telles que le radar automobile ou le WHDMI, la fiabilité est devenue un enjeu extrêmement important pour l'industrie. Dans un émetteur/récepteur radio, les problèmes de fiabilité concernent principalement les transistors MOS intégrés dans les amplificateurs de puissance, compte-tenu des niveaux relativement élevé des puissances. Ces composants sont susceptibles de se détériorer fortement par le phénomène de l'injection de porteurs chauds impactant lourdement les performances des amplificateurs. Ce travail de thèse concerne la conception et l'étude de la fiabilité des amplificateurs de puissance fonctionnant aux fréquences millimétriques en technologies CMOS avancées. Le mémoire est articulé autour de quatre chapitres. Les deux premiers chapitres concernent l'étude, la conception, la modélisation et la caractérisation des éléments actifs et passifs intégrés sur silicium et utilisés pour réaliser des amplificateurs de puissance aux fréquences millimétriques. Le troisième chapitre décrit les trois amplificateurs de puissance conçus et réalisés pour les tests de fiabilité. Enfin, le dernier chapitre propose une étude complète de la fiabilité de ces circuits jusqu'au calcul de leur temps de vie.
10

A Study of Tungsten Metallization for the Advanced BEOL Interconnections

Chen, James Hsueh-Chung, Fan, Susan Su-Chen, Standaert, Theodorus E., Spooner, Terry A., Paruchuri, Vamsi 22 July 2016 (has links) (PDF)
In this paper, a study of tungsten metallization in advanced BEOL interconnects is presented. A mature 10 nm process is used for comparison between the tungsten and conventional copper metallization. Wafers were processed together till M1 dual-damascene etch then separated for different metallization. Tungsten metal line of 24 nm width is showing a 1.6X wire resistance comparing to the copper metal line. Comparable opens/shorts yield were obtained on a 0.8 M comb serpentine, Kelvin-via and 4K via chains. Similar physical profile were also achieved. This study has demonstrated the feasibility of replacing the copper by tungsten at BEOL using the conventional tungsten metallization tools and processes. This could be a cost- effective solution for the low-power products.

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