Ces travaux de thèse portent sur les phénomènes d’amplification du signal de diffusion Raman par effet de surface et par effet de pointe. Des réseaux de motifs métalliques de taille nanométrique arrangés spatialement ont été fabriqués par la méthode de transfert Langmuir-Blodgett et par lithographie à faisceau d’électrons. De telles structures de géométries contrôlées déposées à la surface de lamelles de microscope ont été développées afin d’amplifier le signal Raman de molécules adsorbées par effet SERS (Surface Enhanced Raman Spectroscopy). Ces nanostructures triangulaires en or de taille proche de la longueur d’onde ont des bandes de résonance plasmon dans le domaine spectral visible. En utilisant une source de laser appropriée dans ce domaine spectral, les facteurs d’amplification Raman d’une couche mono-moléculaire d’un dérivé azobenzène sont de plusieurs ordres de grandeur, et ce pour les deux techniques de nano-lithographie employées. Afin de compléter ces premiers résultats, des réseaux de fils d’or avec de grands facteurs de forme ont été fabriqués. Ces derniers montrent des résonances plasmons multipolaires et des facteurs d’amplification de l’ordre de 105. Les techniques de microscopie en champ proche ont également été développées afin de localiser précisément l’exaltation Raman et d’accroitre la résolution spatiale de mesures Raman. Des pointes métalliques en or de taille nanométrique ont ainsi permis d’amplifier localement le signal de diffusion de molécules placées à leur proximité par effet TERS (Tip Enhanced Raman Spectroscopy). Les développements logiciels et mécaniques entre un microscope confocal Raman et un microscope à force atomique ont été implémentés afin de contrôler simultanément les deux instruments. Ce montage expérimental a été appliqué à l’étude de nanofils semi-conducteurs de nitrure de gallium permettant de suivre leur signal vibrationnel avec une résolution spatiale inférieure à 200 nm. / This thesis work focuses on Raman scattering enhancements by metallic nanostructures. In the first part of this work, arrays of metallic patterns with nanometer dimensions were fabricated by the Langmuir-Blodgett deposition technique and electron-beam lithography. Such structures made of gold were fabricated onto microscope slides with the goal to enhance the Raman signal through SERS effect (Surface Enhanced Raman Spectroscopy). These patterns formed by an assembly of triangular nanostructures with sizes of hundreds of nanometers, exhibit plasmon resonance bands in the visible spectral region. By using an appropriate excitation laser source with respect to the plasmon frequency, Raman enhancement factors of a monolayer were found to be of several order of magnitude for both Langmuir-Blodgett and electron-beam lithography platforms. To further complement these results, gold wires arrays with large aspect ratio made by electron-beam lithography showed multipolar plasmon resonances with enhancement factors up to 105. In the second part of this thesis, near-field Raman microscopy has been developed with the aim to localize precisely the Raman enhancement and improve spatial resolution of Raman measurements. Atomic force microscopy gold tips have been used to locally enhance scattering signal of molecules in close proximity to the tip opening new opportunities. This approach known as TERS (Tip Enhanced Raman Spectroscopy) is of significant interest to probe nanomaterials, nanostructures or monolayers. Software and mechanical developments have been made between a confocal Raman microscope and an atomic force microscope to control simultaneously both instruments. This experimental setup was used to characterize gallium nitride semi-conductors nanowires with spatial resolution better than 200 nm.

Electron Beam Induced Deposition (EBID) is a direct write fabrication process with applications in circuit edit and debug, mask repair, and rapid prototyping. However, it suffers from significant drawbacks, most notably low purity. Work over the last several years has demonstrated that deposition from bulk liquid precursors, rather than organometallic gaseous precursors, results in high purity deposits of low resistivity (LPEBID). In this work, it is shown that the deposits resulting from LP-EBID are only highly conductive when deposited at line doses below 25μC/cm. When the dose exceeds this value, the resulting structure is highly porous providing a poor conductive pathway. It is also shown that beam current has no significant effect on the resistivity of the deposits. Nanowires with resistivity significantly lower than the previous best result of 67μΩ•cm were achieved, with the lowest resistivity being only 6.6μΩ•cm, only a factor of 4 higher than that bulk copper of 1.7μΩ•cm.

Nanofabrication techniques were used to manufacture nanometer scale protein templates. The fabrication approach employs electron beam lithography (EBL) patterning on poly(ethylene glycol) (PEG) thiol (CH3O(CH2CH2O)17NHCO(CH2)2SH) self-assembled monolayers (SAM) on Au. The PEG SAM prevented protein surface adhesion and binding sites for protein were created in the SAM by EBL. Subsequent to EBL, the patterns in the PEG SAM were backfilled with 40-nm NeutrAvidin-coated fluorescent spheres (FluoSpheres). The spontaneous and directed immobilization of the spheres from a solution to the patterns resulted in high resolution protein patterns. The FluoSpheres could be arranged in any arbitrary pattern with ultimately only one or a few FluoSpheres at each binding site. Growth dynamics and SAM morphology of PEG on Au were studied by atomic force microscopy (AFM). PEG SAMs on three types of Au with different microstructure were examined: thermally evaporated granular Au and two types of Au films produced by hydrogen flame annealing of granular Au, Au(111) and "terraced" Au (crystal orientation unknown). The different Au surfaces' substructure affected the morphology and mechanical properties of the PEG SAM. On Au(111), AFM imaging revealed monolayer formation through three distinct steps: island nucleation, island growth, and coalescence. The fine-structure of the SAM revealed dendritic island formation - an observation which can be explained by attractive intermolecular interactions and diffusion-limited aggregation. Island growth was not observed on the "terraced" Au. AFM studies of EBL patterned PEG SAMs on Au(111) revealed two different patterning mechanisms. At low doses, the pattern formation occurs by SAM ablation in a self-developing process where the feature depth is directly dose dependent. At higher doses electron beam induced deposition of material, so-called contamination writing, is seen in the ablated areas of the SAM. The balance between these two mechanisms is shown to depend on the geometry of the pattern. In addition to PEG SAMs, fibronectin monolayers on SiO2 surfaces were patterned by EBL. The areas exposed with EBL lose their functionality and do not bind anti-fibronectin. With this approach we constructed fibronectin templates and used them for cell studies demonstrating pattern dependent cell geometries and cell adhesion. / QC 20101008

No description available.

<p>Nanofabrication techniques were used to manufacture nanometer scale protein templates. The fabrication approach employs electron beam lithography (EBL) patterning on poly(ethylene glycol) (PEG) thiol (CH3O(CH2CH2O)17NHCO(CH2)2SH) self-assembled monolayers (SAM) on Au. The PEG SAM prevented protein surface adhesion and binding sites for protein were created in the SAM by EBL. Subsequent to EBL, the patterns in the PEG SAM were backfilled with 40-nm NeutrAvidin-coated fluorescent spheres (FluoSpheres). The spontaneous and directed immobilization of the spheres from a solution to the patterns resulted in high resolution protein patterns. The FluoSpheres could be arranged in any arbitrary pattern with ultimately only one or a few FluoSpheres at each binding site.</p><p>Growth dynamics and SAM morphology of PEG on Au were studied by atomic force microscopy (AFM). PEG SAMs on three types of Au with different microstructure were examined: thermally evaporated granular Au and two types of Au films produced by hydrogen flame annealing of granular Au, Au(111) and "terraced" Au (crystal orientation unknown). The different Au surfaces' substructure affected the morphology and mechanical properties of the PEG SAM. On Au(111), AFM imaging revealed monolayer formation through three distinct steps: island nucleation, island growth, and coalescence. The fine-structure of the SAM revealed dendritic island formation - an observation which can be explained by attractive intermolecular interactions and diffusion-limited aggregation. Island growth was not observed on the "terraced" Au.</p><p>AFM studies of EBL patterned PEG SAMs on Au(111) revealed two different patterning mechanisms. At low doses, the pattern formation occurs by SAM ablation in a self-developing process where the feature depth is directly dose dependent. At higher doses electron beam induced deposition of material, so-called contamination writing, is seen in the ablated areas of the SAM. The balance between these two mechanisms is shown to depend on the geometry of the pattern.</p><p>In addition to PEG SAMs, fibronectin monolayers on SiO2 surfaces were patterned by EBL. The areas exposed with EBL lose their functionality and do not bind anti-fibronectin. With this approach we constructed fibronectin templates and used them for cell studies demonstrating pattern dependent cell geometries and cell adhesion.</p>

" Because technology provides the tools and biology the problems, the two should enjoy a happy marriage ! "1 . Cette phrase resume parfaitement l'esprit du projet qui a motive ces travaux de these. En effet, le couplage des biotechnologies et des micro et nano technologies, resume sous le vocable < Nanobiotechnologies > est une activite en plein essor qui laisse presager de nombreuses applications en particulier dans le domaine de la biodetection. Lobjectif principal de ces travaux est dedie au developpement de strategies d'adressage de biomolecules a l'echelle nanometrique pour des applications de biodetection. Le premier aspect de ce travail est d'ordre technologique. Il concerne la fabrication de dispositifs d'adressage bases sur des reseaux de nanoelectrodes planaires. En utilisant un procede reposant sur lutilisation de la lithographie electronique haute resolution sur un microscope TEM/STEM, nous avons pu demontrer la fabrication de dispositifs a base de nanoelectrodes presentant des espaces inter-electrodes controlables entre 100 et 15nm. Une technique de lithographie alternative, la Nano-Impression est egalement presentee comme une solution possible a la replication de nanodispositifs fabriques par lithographie electronique. La deuxieme partie des travaux est dediee a la mise en place dun schema de detection de nanoparticules que nous avons developpe autour de dispositifs bases sur des reseaux delectrodes inter-digitees. Avant de nous interesser a l'utilisation de ces dispositifs pour une application biologique, nous avons etudie leur reponse electrique vis-a-vis de l'absorption de nanoparticules d'Or par interaction electrostatique. Les premiers resultats obtenus montrent que le schema de detection permet d'atteindre un niveau de sensibilite ultime au travers d'une mesure directe de la conductance des dispositifs. Certaines experiences montrent en effet la possibilite de mesurer electriquement l'adsorption d'une seule nanoparticule. Enfin, la derniere partie de ces travaux est dediee a l'adaptation de ce protocole pour la detection de biomolecules fonctionnalisees par des nanoparticules d'Or. Pour cela, nous avons employe une approche simple basee sur un systeme de reconnaissance entre une molecule cible et une molecule sonde. Ce schema a ete applique a la detection d'interaction antigene/anticorps et nous a permis de transcrire la selectivite de la reconnaissance entre les anticorps dans le depot des nanoparticules qui se traduit par une modification importante de la conductance du dispositif. Les possibilites d'integration ainsi que la compatibilite des dispositifs avec des systemes de microfluidique rendent ce schema de detection particulierement adapte pour le developpement d'un systeme integre de biodetection a tres haute sensibilite. 1 S. Fields, Proc. Natl. Acad. Sci. USA, vol 98, pp 10051-10054 (2001)

Ziele wie eine hohe Auflösung und ein hoher Durchsatz sind bisher in der Elektronenstrahllithografie nicht gleichzeitig erreichbar; es existieren daher die Belichtungskonzepte Gaussian-Beam und Variable-Shaped-Beam (VSB), die auf Hochauflösung respektive Durchsatz optimiert sind. In dieser Arbeit wird der experimentelle Kreuzvergleich beider Belichtungskonzepte mit Hilfe chemisch verstärkter und nicht verstärkter Lacksysteme präsentiert. Als quantitativer Parameter wurde die Gesamtunschärfe eingeführt, die sich durch quadratische Addition der auflösungslimitierenden Fehlerquellen, also Coulomb-Wechselwirkungen (Strahlunschärfe), Lackprozess (Prozessunschärfe) und Proximity-Effekt (Streuunschärfe), ergibt. Für den Vergleich wurden wohldefinierte Prozesse auf 300 mm Wafern entwickelt und umfassend charakterisiert. Weitere Grundlage ist die Anpassung oder Neuentwicklung spezieller Methoden wie Kontrast- und Basedosebestimmung, Doughnut-Test, Isofokal-Dosis-Methode für Linienbreiten und Linienrauheit sowie die Bestimmung der Gesamtunschärfe unter Variation des Fokus. Es wird demonstriert, dass sich mit einer kleineren Gesamtunschärfe die Auflösung dichter Linien verbessert. Der direkte Vergleich der Gesamtunschärfen beider Belichtungskonzepte wird durch die variable Strahlunschärfe bei VSB-Schreibern erschwert. Da für die Bestimmung der Gesamtunschärfe keine Hochauflösung nötig ist, wird das Testpattern mit größeren Shots belichtet und induziert somit eine größere Gesamtunschärfe. Es wird gezeigt, dass die Prozessunschärfe den größten Anteil der Gesamtunschärfe stellt. Außerdem spielt die Streuunschärfe bei Lackdicken kleiner 100 nm und Beschleunigungsspannungen von 50 kV oder größer keine Rolle. / Up to now, targets like high resolution and high throughput can not be achieved at the same time in electron beam lithography; therefore, the exposure concepts Gaussian-Beam and Variable-Shaped-Beam (VSB) exist, which are optimized for high resolution and throughput, respectively. In this work, the experimental cross-comparison of both exposure concepts is presented using chemically amplified and non-chemically amplified resist systems. For quantification the total blur parameter has been introduced, which is the result of the quadratic addition of the resolution limiting error sources, like Coulomb interactions (beam blur), resist process (process blur) and proximity-effect (scatter blur). For the comparison, well-defined processes have been developed on 300 mm wafers and were fully characterized. Further basis is the adaption or the new development of special methods like the determination of contrast and basedose, the doughnut-test, the isofocal-dose-method for line widths and line roughness as well as the determination of the total blur with variation of the focus. It is demonstrated, that the resolution of dense lines is improved with a smaller total blur. The direct comparison of the total blur values of both exposure concepts is complicated by the variable beam blur of VSB writers. Since high resolution is not needed for the determination of the total blur, the test pattern is exposed with larger shots on the VSB writer, which induces a larger total blur. It is shown that the process blur makes the largest fraction of the total blur. The scatter blur is irrelevant using resist thicknesses smaller than 100 nm and acceleration voltages of 50 kV or larger.

The continuing scaling of integrated circuits beyond 22nm technology node poses increasing challenges to Electromigration (EM) reliability for Cu on-chip interconnects. First, the width of Cu lines in advanced technology nodes is less than the electron mean free path which is 39nm in Cu at room temperature. This is a new size regime where any new scaling effect on EM is of basic interest. And second, the reduced line width necessitates the development of new methods to analyze the EM characteristics. Such studies will require the development of well controlled processes to fabricate suitable test structures for EM study and model verification. This dissertation is to address these critical issues for EM in Cu interconnects. The dissertation first studies the initial void growth under EM, which is critical for measurement of the EM lifetime and statistics. A method based on analyzing the resistance traces obtained from EM tests of multi-link structures has been developed. The results indicated that there are three stages in the resistance traces where the rate of the initial void growth in Stage I is lower than that in Stage III after interconnect failure and they are linearly correlated. An analysis extending the Korhonen model has been formulated to account for the initial void formation. In this analysis, the stress evolution in the line during void growth under EM was analyzed in two regions and an analytic solution was deduced for the void growth rate. A Monte Carlo grain growth simulation based on the Potts model was performed to obtain grain structures for void growth analysis. The results from this analysis agreed reasonably well with the EM experiments. The next part of the dissertation is to study the size effect on the electron wind force for a thin film and for a line with a rectangular cross section. The electron wind force was modeled by considering the momentum transfer during collision between electrons and an atom. The scaling effect on the electron wind force was found to be represented by a size factor depending on the film/line dimensions. In general, the electron wind force is enhanced with increasing dimensional confinement. Finally, a process for fabrication of Si nanotrenches was developed for deposition of Cu nanolines with well-defined profiles. A self-aligned sub-lithographic mask technique was developed using polymer residues formed on Si surfaces during reactive ion etching of Si dioxide in a fluorocarbon plasma. This method was capable to fabricate ultra-narrow Si nanotrenches down to 20nm range with rectangular profiles and smooth sidewalls, which are ideal for studying EM damage mechanisms and model verification for future technology nodes. / text

Eine grundlegende Schwierigkeit in der Röntgenoptik liegt in der Bereitstellung geeigneter Optiken. So ist aufgrund der schwachen Wechselwirkung der Röntgenstrahlung mit Materie der Einsatz brechender Optiken nicht sinnvoll, und es wird auf alternative Konzepte wie Röntgenwellenleiter zurückgegriffen. Röntgenwellenleiter sind nicht-dispersive strahlführende Optiken, welche die Kohärenz der Röntgenstrahlung filtern und als quasi-Punktquellen fungieren. Hierbei wird der Röntgenstrahl in einer oder zwei Dimensionen räumlich beschränkt, wobei der Wellenlängenbereich der Röntgenstrahlung eine Abmessung im sub-100 nm-Bereich erfordert. In der vorliegenden Arbeit wurde ein Verfahren etabliert, mit welchem die Herstellung von Wellenleiterkanälen im sub-50 nm-Bereich in Silizium gelingt. Die Prozessierung basiert hierbei auf einem Schema aus elektronenstrahllithographischer Belichtung, Reaktivem Ionenätzen und Wafer bonding. Das Verfahren ist variabel in Bezug auf verschiedene Wellenleitergeometrien, beispielsweise gekreuzte Wellenleiter und Kanalwellenleiter, ist auf alternative Materialien übertragbar, und erlaubt die Strahlführung auf in einer Dimension gekrümmten Pfaden. Die im Rahmen der vorliegenden Arbeit hergestellten Wellenleiter wurden erfolgreich an verschiedenen Synchrotron-Messplätzen eingesetzt und ihre Fernfelder charakterisiert, und der kohärente Wellenleiterstrahl wurde in der Röntgenmikroskopie und der holographischen Bildgebung eingesetzt. Es finden sich sowohl für die Quellgröße der Wellenleiter als auch für die Auflösung in der Bildgebung Werte im sub-50 nm-Bereich.

A novel localized surface plasmon resonance (LSPR) sensor that differentiates between background refractive index changes and surface-binding of a target analyte (e.g. a target molecule, protein, or bacterium) is presented. Standard, single channel LSPR sensors cannot differentiate these two effects as their design allows only one mode to be coupled. This novel technique uses two surface plasmon modes to simultaneously measure surface binding and solution refractive index changes. This increases the sensitivity of the sensor. Different channels or modes can be created in sensors with the introduction of gold nanospheres or gold nanorods that act as receptor mechanisms. Once immobilization was achieved on gold nanospheres, the technique was optimized to achieve the same immobilization for gold nanorods to get the expected dual mode spectrum. Intricate fabrication methods are illustrated with using chemically terminated self assembled monolayers. Then the fabrication process advances from chemically silanized nanoparticles, on to specific and systematic patterns generated with the use of Electron Beam Lithography. Comparisons are made within the different methods used, and guidelines are set to create possible room for improvement. Some methods implemented failed, but there was a lot to learn from these unsuccessful outcomes. Finally, the applications of the dual mode sensor are introduced, and current venues where the sensors can be used in chemical and biological settings are discussed.