Ces dernières années, l’évolution de la taille des circuits intégrés a été dirigée par la loi de Moore conduisant à des noeuds technologiques de 22 nm et en-deçà. Cependant, les problématiques de performances, de taille et de coût des composants rendent cette conjecture difficile à suivre. La tendance de diversification appelée « More than Moore » consiste à intégrer des fonctions analogiques avec des technologies CMOS dans le but d’optimiser les coûts.L'une de ses technologies clés est le TSV, qui maintient le contact entre deux niveaux de composants. Leurs facteurs de forme devenant de plus en plus élevés, les techniques de dépôts standards par iPVD sont proches de leurs limites. De plus, les méthodes de caractérisation usuelles ne sont pas adaptées à ces structures.La première partie de cette thèse sera dédiée au développement des procédés de dépôt de la barrière de diffusion du cuivre par MOCVD à basse température pour s’adapter aux divers schémas d'intégration de type via middle et via last. La deuxième partie sera consacrée à l’élaboration des protocoles avancés de caractérisation des films dans ces structures afin d’étudier leurs comportements en intégration. / For the past years, Moore’s law has pointed mainstream microelectronics, driving integrated circuits down to 22 nm and below. Yet, performance, dimension and cost issues make it difficult to follow the trend. Integrating analog functions into CMOS-based technologies enables cost-optimized systems solutions. These diversified tendencies are known as “More than Moore”. One of the key technologies of this trend is the TSV, which maintains the contact between two components.The increasing aspect ratio of via made it critical to obtain a continuous, conformal coverage of the copper diffusion barrier layer using iPVD.In the first part of this thesis, a promising deposition technique by MOCVD has been developed at low temperature to fulfill various integration schemes including via last and via middle processes.Characterizations of the behavior of these materials in the TSV then became a great challenge in order to handle the integration protocol. Working at theses scales makes standard methods limited to evaluate the intrinsic properties inside the TSV. In the second part, the implementations of advanced characterization into these structures were carried out.

The Bethe-Weizsäcker cycle consists of a set of nuclear reactions that convert hydrogen into helium and release energy in the stars. It determines the luminosity of low-metal stars at their turn-off from the main-sequence in the Hertzsprung-Russel diagram, so its rate enters the calculation of the globular clusters’ age, an independent lower limit on the age of the universe. The cycle contributes less than 1% to our Sun’s luminosity, but it produces neutrinos that can in principle be measured on Earth in underground experiments and bring direct information of the physical conditions in the solar core, provided that the nuclear reaction rate is known with sufficient precision. The 14N(p,γ)15O reaction is the slowest reaction of the Bethe-Weizs¨acker cycle and establishes its rate. Its cross section is the sum of the contributions by capture to different excited levels and to the ground state in 15O. Recent experiments studied the region of the resonance at Ep = 278 keV. Only one modern data set from an experiment performed in 1987 is available for the high-energy domain. Both energy ranges are needed to constrain the fit of the excitation function in the R-matrix framework and to obtain a reliable extrapolated S-factor at the very low astrophysical energies. The present research work studied the 14N(p,γ)15O reaction in the LUNA (Laboratory for Underground Nuclear Astrophysics) underground facility at three proton energies 0.36, 0.38, 0.40MeV, and in Dresden in the energy range Ep = 0.6 - 2MeV. In both cases, an intense proton beam was sent on solid titanium nitride sputtered targets, and the prompt photons emitted from the reaction were detected with germanium detectors. At LUNA, a composite germanium detector was used. This enabled a measurement with dramatically reduced summing corrections with respect to previous studies. The cross sections for capture to the ground state and to the excited states at 5181, 6172, and 6792 keV in 15O have been determined. An R-matrix fit was performed for capture to the ground state, that resolved the literature discrepancy of a factor two on the extrapolated S-factor. New precise branching ratios for the decay of the Ep = 278 keV resonance were measured. In Dresden, the strength of the Ep = 1058 keV resonance was measured relative to the well-known resonance at Ep = 278 keV, after checking the angular distribution. Its uncertainty is now half of the error quoted in literature. The branching ratios were also measured, showing that their recommended values should be updated. Preliminary data for the two most intense transitions off resonance are provided. The presence in the targets of the other stable nitrogen isotope 15N with its well- known isotopic abundance, allowed to measure the strength of two resonances at Ep = 430 and 897 keV of the 15N(p,αγ)12 C reaction, improving the precision for hydrogen depth profiling.

Es wurden die Zusammenhänge zwischen den Herstellungsbedingungen und dem nanostrukturellen Aufbau von Multischichten, mit Rücksicht auf das mechanische Verhalten aufgeklärt. Dazu wurden durch plasmaunterstützte Gasphasenabscheidung (PACVD) Hartmetallsubstrate mit Viellagen beschichtet und vorrangig mittels analytischer Transmissionselektronenmikroskopie (TEM) charakterisiert. Als Schichkomponenten wurden hauptsächlich TiN und Al2O3 untersucht, daneben aber auch Schichtsysteme der Komponenten AlON, (TiAl)N, und (Ti,Al)ON. Darüber hinaus wurden noch TiC-aC (TiC mit amorphem Kohlenstoffanteil)-Schichten einbezogen. Ziel waren gleichmäßige Multischichten mit Korngrößen von einigen Nanometern, geringer Testur und geringer Mikrorissdichte, die hart sind und gut haften. Die TEM-Untersuchungen dienten insbesondere der Aufklärung der Nanostruktur in den Interface-Bereichen der Schichtsysteme, wobei an Hand der Elektronenenergie-Verlustspektroskopie (EELS) sowohl element- als auch phasenspezifische Signale ausgewertet wurden. Zur verbesserten Bewertung der anfallenden Datenmengen wurden z. T. faktoranalytische Methoden eingesetzt. Je nach Prozessführung der Schichtherstellung kommt es in den Interface-Bereichen zur Durchmischung der Komponenten. Insbesondere führt diffundierender Sauerstoff zur Bildung von TiO2, was sich nachteilig auf die Qualität der Schichten auswirkt. Die Tiefe der "gestörten" Zonen begrenzt die wünschenswerte Verringerung der Einzelschichtdicken. Als wirkungsvolle Gegenmaßnahme hat sich der Einbau von Kohlenstoff erwiesen, wodurch sich dünnere Einzelschichten verwirklichen lassen.

Mit zunehmender Miniaturisierung mikroelektronischer Bauelemente steigen die Anforderungen an reproduzierbare qualitätskonforme Schichten. Um die zur Herstellung notwendigen ALD/PVD/CVD-Schichtabscheideanlagen in einen zuverlässigen Zustand zu versetzen, ist eine regelmäßige Kammerreinigung notwendig. Während des Abscheideprozesses werden nicht nur das Substrat, sondern auch die umliegenden Kammerteile beschichtet. Diese Schichten wachsen mit jedem Beschichtungszyklus weiter an. Der Stress zwischen Schicht und Kammerwand steigt beständig, und es besteht das Risiko das Teile abplatzen und auf die Waferoberfläche fallen und damit die Struktur unbrauchbar machen. Um das zu verhindern, muss die Kammerwand in einen regelmäßigen Zustand versetzt werden, in dem sichergestellt ist, daß keine Schichtreste abplatzen können. In der vorliegenden Arbeit wird ein neues Verfahren zur Trockenreinigung von ALD-Titannitrid Kammern vorgestellt. Dazu wurden TiN-Stücke (hergestellt im ALD, CVD, PVD-Verfahren) auf einem temperaturgeregelten Probenhalter platziert. Eine Argon/NF3 Gasmischung wurde in einer externen Plasmaquelle (RPS) zerlegt und in die Reaktionskammer geschleust. Die Ätzung wurde mit in-situ Reflexionsmessung beobachtet. Experimente mit Chlorzugabe wurden unternommen und ein starker Einfluss auf den Ätzmechanismus beobachtet. Die Ätzraten des TiN sind exponentiell abhängig von der Temperatur und proportional abhängig von der Verfügbarkeit atomaren Fluors. Dieses wird bei der Zerlegung von NF3 frei gesetzt und steht der Reaktion zur Verfügung. Die NF3-Zerlegung in Fluor und Stickstoff wurde mit Hilfe der Massenspektrometrie (QMS) untersucht, Zerlegungsgrade größer 96% wurden erreicht. Mit Hilfe dieser Messung kann der Einfluss der Kammerreinigung auf den Treibhausgasausstoß (GWP) bestimmt werden. Mit dem Ar/NF3-Verfahren können die GWP-Emissionen um 90% im Vergleich zur RIE-Ätzung mit SF6 reduziert werden. Mit Argon/Chlor-Plasmen konnte kein Titannitrid geätzt werden, da die physikalische Sputterkomponente fehlte. Durch Hinzufügen von Chlor zu einer Ar/NF3-Gasmischung konnte die Ätzrate um bis zu 270% im Bereich niedrige Temperaturen/niedriger Druck gesteigert werden. Bei höheren Temperaturen/höherem Druck fielen die Ar/NF3/Chlor Ätzraten allerdings deutlich hinter die des Ar/NF3 zurück. Die dazu führenden Effekte werden untersucht und ausgeführt. Die Nutzung von externen Plasmaquellen bietet eine vielversprechende Alternative um Abscheideanlagen von TiN-Rückständen reinigen zu können. Bei hohen Temperaturen werden deutlich höhere Ätzraten als bei anderen Schichten (SiN, SiO2, W) erreicht. Für Anwendungen im niedrigen Temperaturbereich erlaubt die Zugabe von Chlor interessante Anwendungsmöglichkeiten. / Demands on state of the art deposition technologies for semiconductor production focus on uniformity, repeatability and low defectivity. The chamber condition is a key parameter to achieve these high demands in chemical vapour deposition (CVD) processes and are even more critical to the atomic layer deposition processes (ALD). During the deposition process not only the wafer surface but other chamber parts as well are covered with a thin film. This film accumulates during the deposition cycles and is prone to fall off the walls and pollute the wafer surface. The chamber parts that are exposed to the deposition must be set back to a steady state so that no deposits fall off the walls. The chamber condition also changes uncontrolled with varying film condition on the wall. A new approach for cleaning of ALD-titanium nitride (TiN) deposition chambers was investigated. To determine etch rates TiN-samples (created by ALD, CVD and PVD) were placed on a temperature controlled sample holder. An argon/NF3 mixture was excited in an upstream remote plasma source (RPS) and then routed through the reaction chamber. No further plasma activation inside the reaction chamber was done. The etching was monitored by in-situ reflectometry and etch rates were calculated. The effect of chlorine addition was also studied and strong influence on etch rates was found. The etch rate of TiN is dependent exponentially on temperature and very low etch rates were achieved below 70◦C at a chamber pressure ranging from 20-300 Pa. It was found that this correlates very well with the vapour pressure of the reaction product TiF4. At temperatures of 300◦C etch rates up to 800 nm/min were achieved. The optimum pressure for etching was found at 100 Pa while the pressure effect was small. The etch rate was mainly dependent on the availability of activated fluorine to create TiF4 by the reaction 2 NF3 → N2 + 6 F* 2 TiN + 8 F* → 2 TiF4 + N2 The NF3 decomposition to nitrogen and fluorine was monitored by quadrupole mass spectrometry (QMS) and was found to be greater than 96%. This figure allows an estimation of the amount of Global warm potential (GWP) gas emmited by the process for environmental considerations. Using argon/NF3 or argon/fluorine mixtures in RPS devices reduces the GWP emissions by more than 90% compared to RIE plasma cleaning with SF6. No etching occurred by using argon/chlorine only mixtures as no physical etch component was involved in RPS etch. However adding chlorine to the argon/NF3 mixture accelerated the etching process. Chlorine addition to the argon/NF3 mixture increased the etch rates up to 270% in the low pressure/low temperature regime. At higher temperatures or higher pressures the etch rates dropped below the etch rates achieved solely with fluorine chemistry. It must be emphasized that there is no physical acceleration of the ionized molecules toward the etched sample in this remote plasma setup. The usage of a remote plasma offers an alternative way to remove residues from chambers running TiN deposition processes. At high temperatures the Ar/NF3 offers remarkably high etching rates for TiN compared to other films (silicon nitride, -oxide, tungsten) usually cleaned by remote plasma. For low temperature applications the chlorine enhancement offers an interesting alternative to accelerate the etch process.

The identity of the Tin Can Tourists of the World, the first recreation automobile organization, has been poorly defined in the historical discourse, the factors contributing to the 1919 formation of the organization in Tampa, Florida represents a landmark shift in tourism in America towards the automobile. The group’s subsequent solidification of a distinct identity gives insight beyond their organization. The thesis defines their identity as well as looks at their impact on American automobility and tourism. The thesis therefore focuses on the previously undefined concept of recreational automobility giving it definition and showing how the group helped to define it. The group’s early role in mass use and adaptation of the automobile for recreation represents the first steps in creating a market for recreational vehicles. The imposition of organization on the camping experience by the Tin Can Tourists and their influence on creating special places for the practice of their activities helped define recreational automobility. The footprint left by the Tin Can Tourists helped shape part of America’s modern tourist industry. The legacy of their ideas about recreational automobility also suggests influence they had on later groups using recreational vehicles. This thesis examines and clarifies the identity and influence of the Tin Can Tourists of the World as a window on important trends in automobility and tourism.

Current concentrated solar power plants (CSP) use molten salt at 565°C as a heat transfer and energy storage fluid. Due to thermal energy storage (TES), these solar plants can deliver dispatachable electricity to the grid; however, the levelized cost of electricity (LCOE) for these plants is 12-15 c/kWh, about 2.5 times as high as fossil fuel electricity generation. Molten salt technology limits peak operating temperatures to 565°C and a heat engine efficiency of 40%. Liquid metal (LM), however, can reach >1350°C, and potentially utilize a more efficient (60%) heat engine and realize cost reductions. A 1350 °C LM-CSP plant would require ceramic containment, inert atmosphere containment, additional solar flux concentration, and redesigned internal receiver. It was initially unclear if these changes and additions for LM-CSP were technically feasible and could lower the LCOE compared to LS-CSP. To answer this question, a LM-CSP plant was designed with the same thermal input as a published LS-CSP plant. A graphite internal cavity receiver with secondary concentration heated liquid Sn to 1400°C and transferred heat to a 2-phase Al-Si fluid for 9 hours of thermal energy storage. Input heat to the combined power cycle was 1350°C and had 60% thermal efficiency for a gross output of 168 MW. The cost of this LM-CSP was estimated by applying material cost factors to the designed geometry and scaling construction costs from published LS-CSP estimates. Furthermore, graphite was experimentally tested for reactivity with liquid Sn, successful reaction bonds, and successful mechanical seals. The result is switching to molten metal can reduce CSP costs by 30% and graphite pipes, valves, and seals are possible at least at 400°C.

The reaction of the lithium tris(2-pyridyl)stannate [LiSn(2-py6OtBu)3] (py6OtBu = C5H3N-6-OtBu),1, with the element(II) amides E{N(SiMe3)2}2 (E = Sn, Pb) afforded complexes [LiE{Sn(2 py6OtBu)3}3] for E = Sn (2) and E = Pb (3), which reveal three Sn–E bonds each. Compounds 2 and 3 have been characterized by solution NMR spectroscopy and X-ray crystallographic studies. Large 1J(119Sn–119/117Sn) as well as 1J(207Pb–119/117Sn) coupling constants confirm their structural integrity in solution. However, contrary to 2, complex 3 slowly disintegrates in solution to give elemental lead and the hexaheteroarylditin [Sn(2-py6OtBu)3]2 (4).

Thesis (PhD)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: The aim of this thesis is to use tin-mediated reactions to differentiate between the four zones in the myo-inositol ring that consists of five contiguous equatorial and one axial hydroxyl groups. It is expected to give chemical control over the hexitol that can be put to good use in commercializing the phosphate derivatives of myo-inositol that are of pharmaceutical value. As point of departure 1,2-0-cyclohexylidene-myo-inositol (II.I) was synthesized that contains a tetrol with one end adjacent to an axial acetal oxygen and the other end adjacent to an equatorial acetal oxygen. The selective protection of position 3 (Dmyo- inositol) was investigated. Various problems lead to the selective silylation of the acetal at position 5. The silane forms the basis of the subsequent investigation because the cyclitol is now divided into an isolated mono-ol and a trans-diol allowing for easier differentiation between the various hydroxyl groups. It was indeed possible to differentiate the trans-diol from the mono-ol by using carbonylation and allylidenation. Ring closure occurs in both cases. In the carbonylation case the resultant five-membered ring is less stable than that of the allylidene due to the Sp² hybridized carbon atom of the carbonate compared to theSp³ hybridized carbon of the allylidene group. Preliminary work was done on the racerrue 1,2-0-cyclohexylidene-myo-inositol (II.VII) in order to use the acquired technology on the chiral camphor analog. The transition from racemic to chiral proved problematic since the camphor acetal is difficult to prepare and its selective silylation differs from that observed for cyc1ohexylidene. The camphor acetal itself was silylated in the process. (S)-( -)-Camphanic chloride was therefore used as chiral auxiliary in the protection of position six of the racemic 1,2,3,4,5-protected myo-inositol, thus solving the problems encountered in the protection of position six whilst combining the protection and chiral induction steps. The resultant diastereomers could both be used in the synthesis of IP₃ and IP₄ respectively, eliminating the disposal of half ofthe product. This project lead to the development of useful chiral differentially protected myoinositol derivatives, which could be useful in synthesis of various other myo-inositol derivatives. Besides the synthesis of useful chiral differentially protected myo-inositol derivatives, this investigation developed new applications in the tin-mediated derivatization of sugars. The following compounds were synthesized during this investigation. Bold numbers indicates novel compounds. / AFRIKAANSE OPSOMMING: Die doel van hierdie proefskrif is om met behulp van tin-bemiddelde reaksies onderskeid te maak tussen die vier sones in die mia-inositolring, wat bestaan uit vyf aaneenlopende ekwatoriale hidroksigroepe en een aksiale hidroksigroep. Die verwagting was om vinnig, effektiewe chemiese beheer oor die genoemde heksitol te verkry om sodoende chemies en kommersiëel munt te slaan uit die farmaseutiese werking van die fosfaatafgeleides van mia-inositol. As eerste uitgangspunt is 1,2-0-sikloheksilideen-mia-inositol (II.I) berei, wat lei tot die vorming van 'n tetrol waarvan die een punt naasliggend aan 'n aksiale asetaalsuurstofatoom en die ander punt naasliggend aan 'n ekwatoriale asetaalsuurstof is. As voortsetting is die selektiewe beskerming van posisie 3 (D-mia-inositol) ondersoek. Velerlei probleme lei tot die selektiewe sililering van die asetaal by posisie 5 (II.VII). Die silieleter vorm die basis van al die daaropvolgende ondersoeke omdat dit die siklitol in 'n trans-diol en 'n geïsoleerde mono-ol verdeel en die verskillende hidroksigroepe daarvan makliker van mekaar onderskei kan word. Dit is inderdaad moontlik om die trans-diol van die mono-ol te onderskei deur karbonilering of allilidenering. In albei gevalle vind ringannulering plaas. In die geval van die karbonilering is die gevormde vyflidring minder stabiel as wat die geval is vir die allilideengroep. Die rede hiervoor is dat die karbonaatkoolstofatoom Sp²- gehibridiseer is terwyl die ooreenstemmende koolstofatoom van die allilideen Sp³- gehibridiseer is. Ontwikkelingswerk is op die rasemiese 1,2-0-sikloheksilideen-mia-inositol (II.VII) gedoen ten einde dit op die chirale kamferasetaalanaloog toe te pas. Die oorgang van rasemies na chiraal is egter problematies aangesien die kamferasetaal moeiliker vorm en selfs as dit vorm toon die reaksies, soos byvoorbeeld die sililering, ander selektiwiteit as wat die geval is vir die rasemiese mengsel. Sililering van die kamferasetaallei tot sililering van die kamfer self. (S)-(-)-kamfanoïelchloried is gevolglik as chirale hulpreagens gebruik om posisie 6 van die rasemiese 1,2,3,4,5-beskermde-mia-inositol te beskerm. Hierdie benadering los die problematiek rondom die beskerming van posisie 6 sowel as die induksie van chiraliteit op. Die twee diastereomere wat op hierdie wyse vorm, kan albei in die sintese van onderskeidelik IP₃ en IP₄ gebruik word, wat die verlies aan helfte van die produk verhoed. Behalwe die daarstelling van bruikbare chirale differensiëel-beskermde mioinositolafgeleides wat gebruik kan word om 'n verskeidenheid chirale mioinositolafgeleides te berei, het hierdie ondersoek nuwe toepassings in tin-bemiddelde derivatisering van suikers daargestel. Die volgende verbindings is gedurende die verloop van hierdie ondersoek gesintetiseer, waar verbindings vir die eerste keer gesintetiseer is word dit aangedui deur die verbinding se nommer vet (bold) te druk.

Chemical Engineering / The successful commercialization of lithium-ion batteries is responsible for the ubiquity of personal electronics. The continued development of battery technology, as well as its application to new emerging markets such as electric vehicles, is dependent on developing safer, higher energy density, and cheaper electrode materials and battery chemistries. The focus of this dissertation is on identifying, characterizing and optimizing new materials for lithium- and sodium-ion batteries. Batteries are incredibly complex engineered systems with each electrode composed of conductive additive and polymeric binder in addition to the active material. All of these components must work together for the electrode system to function properly. In this work, glancing angle deposition (GLAD) and reactive ballistic deposition (RBD) are employed to grow thin films of novel materials with reproducible morphology for use as battery electrodes. The use of these thin film electrodes eliminated the need for conductive additives and polymer binders allowing for the active materials themselves to be studied rather than the whole electrode system. Two techniques are employed to modify the chemical properties of the electrode materials grown by RBD and GLAD: Alloying (Si-Ge alloys for Li-ion batteries and Sn-Ge alloys for Na-ion batteries) and partial chalcogenation (partial oxidation of silicon, and partial sulfidation and selenidation of germanium for Li-ion batteries). Both of these techniques are successfully employed to enhance the electrochemical properties of the materials presented in this dissertation. / text

Understanding interfacial charge injection processes is one of the key factors needed for development of efficient organic electronic devices, such as biosensors and energy conversion systems, since these processes control the electrical characteristics of these devices. Spectroelectrochemical characterization of electron transfer processes occurring at the electrode - electroactive thin film interface has been evaluated to improve our understanding of charge transfer kinetics using a novel form of electroreflectance spectroscopy, potential-modulated attenuated total reflectance (PM-ATR), which makes it possible to sensitively monitor spectroscopic changes in thin films as a function of applied potential.PM-ATR was used to evaluate three different redox-active films deposited on indium tin oxide (ITO) electrodes to investigate: i) the orientation dependence of charge transfer rates of thin films of biomolecules, ii) surface treatment and modification effects on charge transfer kinetics of conducting polymers and, iii) estimation of rates of electron injection and conduction band edge of semiconductor nanocrystalline materials.First, Prussian blue film as a model system was used successfully to examine the PM-ATR technique for determination of the charge transfer rate constant between ITO and a molecular film.Second, an anisotropic and redox active protein film, cytochrome c, was used to probe charge transfer rates with respect to molecular orientation. The electron transfer rate measured using TM polarized light was four-fold greater than that measured using TE polarized light. These data are the first to correlate a distribution of molecular orientations with a distribution of electron transfer rates in a redox-active molecular film.Third, the effects of ITO surface treatment and modification on charge transfer kinetics on a conducting polymer, poly(3,4-ethylenedioxythiophene/)/poly(styrenesulfonate) (PEDOT/PSS), were studied. The apparent interfacial charge transfer rate constant for PEDOT/PSS on ITO has been reported for the first time which cannot be measured otherwise with conventional electrochemistry due to high non-Faradaic background of PEDOT/PSS films.Fourth, PM-ATR enabled characterization of reversible redox processes between submonolayer coverages of surface-tethered, CdSe nanocrystals and ITO for the first time. Optically determined onset potentials for electron injection were used for estimation for the conduction band and valance band energies (ECB and EVB, respectively).