Das Ziel der vorliegenden Arbeit war die erstmalige, umfassende und systematische Untersuchung aller Teilprozesse bei der ionenstrahlgestützten Schichtabscheidung (IBSD). Silber (Metall) und Germanium (Halbleiter) wurden als Beispielsysteme ausgewählt, da auf Grund der unterschiedlichen Eigenschaften der beiden Materialien prinzipielle Unterschiede in der Zerstäubung und Schichtabscheidung zu erwarten sind. Zur Bearbeitung der wissenschaftlichen Fragestellung erfolgte eine Charakterisierung der Primärteilchen sowie der zerstäubten und gestreuten Teilchen bezüglich ihrer Energie und Winkelverteilung sowie eine Charakterisierung der abgeschiedenen Schichten bezüglich ihrer Schichtdicke, Komposition, Struktur, Oberflächentopographie, elektrischen und optischen Eigenschaften unter Variation der Art (Argon und Xenon), der Energie (0.5 keV–1.5 keV) und des Einfallswinkels der Primärteilchen relativ zur Targetnormalen (0°–60°) sowie des betrachteten polaren Emissionswinkels (-40°–90°). Die dargestellten Ergebnisse demonstrieren den systematischen Einfluss der primären Prozessparameter (Ionenart, Energie, Einfallswinkel und Emissionswinkel) auf die Eigenschaften der zerstäubten und gestreuten Teilchen und auf die Eigenschaften der erzeugten Silber- und Germaniumschichten, wobei die Eigenschaften der abgeschiedenen Schichten mit den Eigenschaften der schichtbildenden Teilchen korrelieren. Bei der IBSD von Silber führt der Einfluss der hochenergetischen zerstäubten und gestreuten Teilchen auf die Schichten zu kleineren mittleren Korngrößen und damit zu höheren spezifischen Widerständen und Variationen in den optischen Eigenschaften. Die Untersuchungen zur IBSD von Germanium zeigen, dass der Einbau von Prozessgas in die abgeschiedenen Schichten mit der Anzahl der gestreuten Primärionen, deren Energie hoch genug für eine Implantation in die Schicht ist, korreliert werden kann.

The goal of this research was to devise a new analytical technique, using Accelerator Mass Spectrometry (AMS), to measure Platinum Group Element (PGE) concentrations to the sup-ppb levels in natural, insulating, samples. The challenges were threefold. First, a method of sputtering an insulating sample to successfully produce a stable beam of anions needed to be devised. Second, a suitable standard of known PGE concentrations had to be found and third, spectral analysis of the beam had to verify any claims of PGE abundance. The first challenge was met by employing a modified high intensity negative ion source flooded with neutral caesium that successfully sputtered insulators to produce a beam of negative ions. The second challenge, that of finding a suitable standard, was fraught with difficulties, as no synthesized standards available were found to be appropriate for this work. As a result, direction is provided for future production of standards by ion implantation. The third challenge, successful spectral analysis, was accomplished using a newly designed gas ionization detector which allowed for resolution of the interfering molecular fragment from the PGE ions. Coupled with the use of the SRIM computer programme, positive identification of all peaks in the spectra of the analyzed samples was accomplished. The success of the first and third challenges lead to the qualitative analyses of geological samples for sub-ppb levels of PGE by AMS. Quantitative analyses await only for the appropriate standards and with those will come a whole new range of research possibilities for measuring sub-ppb levels of PGE in insulating samples by AMS.

The inert gas ion bombardment of solid surfaces has found many uses in the field of analytical chemistry. In one method of spectrochemical analysis, inert gas ion bombardment in a glow discharge is used to produce an atomic vapor, representative of the sample bulk, which is analyzed using atomic absorption techniques. Gas jets directed at the sample surface during the discharge increase the removal rate of sample material from the surface. Such bombardment of solid surfaces results in changes to the surface which are visually evident in the formation of craters and surface deposits. This thesis was designed to gain a better understanding of the changes in a brass surface caused by jet-enhanced sputtering. Electron spectroscopy for chemical analysis (ESCA) is used to study selected regions of the surface. Changes in chemical composition were observed as successive atomic layers were removed from the sample. The results of this investigation indicate that the effects of ion bombardment can be explained in terms of the selective sputtering of one bulk component over another. The surfaces of the sputtered craters were found to be depleted of the higher sputtering yield component, Zn, when compared to the bulk composition. In a deposit, the component with the highest sputtering yield was found to be more concentrated in layers closest to the bulk material. The component with the lowest sputtering yield was found at relatively higher concentrations nearest the deposit surface. The component with the higher sputtering yield is selectively sputtered first during the glow discharge, and consequently is deposited with a higher concentration closest to the bulk, the converse being true for the lowest sputtering yield component. / Graduation date: 1993

Thin film technology is of great significance for a variety of products, such as electronics, anti-reflective or hard coatings, sensors, solar cells, etc. This thesis concerns the synthesis of thin functional films, reactive magnetron sputter deposition process as such and the physical and functional characterization of the thin films synthesized. Characteristic for reactive sputtering processes is the hysteresis due to the target poisoning. One particular finding in this work is the elimination of the hysteresis by means of a mixed nitrogen/oxygen processing environment for dual sputtering of Alumina-Zirconia thin films. For a constant moderate flow of nitrogen, the hysteresis could be eliminated without significant incorporation of nitrogen in the films. It is concluded that optimum processing conditions for films of a desired composition can readily be estimated by modeling. The work on reactively sputtered SiO2–TiO2 thin films provides guidelines as to the choice of process parameters in view of the application in mind, by demonstrating that it is possible to tune the refractive index by using single composite Six/TiO2 targets with the right composition and operating in a suitable oxygen flow range. The influence of the target composition on the sputter yield is studied for reactively sputtered titanium oxide films. It is shown that by using sub-stoichiometric targets with the right composition and operating in the proper oxygen flow range, it is possible to increase the sputter rate and still obtain stoichiometric coatings. Wurtzite aluminum nitride (w-AlN) thin films are of great interest for electro-acoustic applications and their properties have in recent years been extensively studied. One way to tailor material properties is to vary the composition by adding other elements. Within this thesis (Al,B)N films of the wurtzite structure and a strong c-axis texture have been grown by reactive sputter deposition. Nanoindentation experiments show that the films have nanoindentation hardness in excess of 30 GPa, which is as hard as commercially available hard coatings such as TiN. Electrical properties of w-(Al,B)N thin films were investigated. W-(Al,B)N thin films are found to have a dielectric strength of ~3×106 V/cm, a relatively high k-value around 12 and conduction mechanisms similar to those of AlN. These results serve as basis for further research and applications of w-(Al,B)N thin films. An AlN thin film bulk acoustic resonator (FBAR) and a solidly mounted resonator (SMR) together with a microfluidic transport system have been fabricated. The fabrication process is IC compatible and uses reactive sputtering to deposit piezoelectric AlN thin films with a non-zero mean inclination of the c-axis, which allows in-liquid operation through the excitation of the shear mode. The results on IC-compatibility, Q-values, operation frequency and resolution illustrate the potential of this technology for highly sensitive low-cost micro-biosensor systems for applications in, e.g. point-of-care testing.

This thesis investigates the electrochromic NixW1-x oxide thin film system, where 0 < x < 1. The thin films were deposited by reactive DC magnetron co-sputtering from one Ni and one W metal target. In addition, Ni oxide was deposited with water vapor added to the sputtering gas. The different compositions were structurally characterized by X-ray diffraction, X-ray photoelectron-, Rutherford backscattering- and Raman spectroscopy. Possible nanostructures were studied by ellipsometry together with effective medium theory. Optical and electrochemical properties were investigated by spectrophotometry and cyclic voltammetry in 1 M lithium perchlorate in propylene carbonate (Li-PC). Li-PC electrolyte was used as it is being compatible with both W and Ni oxides. Few studies have previously been made on Ni oxides in Li-PC. Films with high Ni content, 0.85 < x < 1, were polycrystalline and all other films were amorphous. W-rich films, x < 0.5, consisted of a mixture of W oxide and NiWO4 -phases, and the Ni-rich samples, x > 0.5, probably consisted of hydrated Ni oxide and NiWO4 -phases. Films with 0 < x < 0.3 showed electrochromic properties similar to W oxide, and films with 0.7 < x < 1 behaved as Ni oxide. For 0.4 < x < 0.7 no optical change was seen. At the border of cathodic electrochromic and non-electrochromic behavior, i.e. x ~ 0.4, the sample behaved as an optically passive intercalation material. The transmittance change was 0.45 and 0.15 for the W-rich and Ni-rich films, respectively. Ni addition to W oxide improved the coloration efficiency. For the Ni-rich films the charge insertion/extraction and optical modulation was low and an aging effect resulted in strong bleaching of the samples. The advantage of W addition to Ni oxide was that the transparency at the bleached state was enhanced. Moreover, it was found that the hydrous character of the Ni oxide had a large impact on the electrochromic performance, both when electrochemically cycled in KOH and in the non-aqueous Li-PC.

Dissertation (Ph.D.)--University of Toledo, 2009. / Typescript. "Submitted as partial fulfillment of the requirements for the Doctor of Philosophy in Physics." Bibliography: leaves 132-148.

Thesis (Ph. D.), Oregon Graduate Institute of Science & Technology, 1996.

Thesis (M.S.)--Rochester Institute of Technology, 2006. / Typescript. Includes bibliographical references (leaves 145-146).

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: The nano-age is more about the mesoscopic phenomena, than those occurring at molecular and atomic level, which have been studied by chemists and physicists for more than a hundred years. Nanotechnology is currently one of the most active fields being explored in many different disciplines by many scientists across the world. In this research field, it is imperative to continually create more effective and superior methods to build smaller and smaller electronic devices, circuits and sensors. Technology is being improved continually and, specifcally at our university, there was a need to improve our device manufacturing facility. The aim of this work was to create a new sputtering system, build a dry etching system and to make modifications to upgrade existing equipment. This work has been done to produce nano structures or devices and, most importantly, to save costs. New systems and equipment have been built to keep up with the progress in this field. In order to understand the significance of the different types of equipment used in the fabrication of thin film superconductor layers, an overview will be given of the complete process of manufacturing a patterned Josephson junction. The apparatus used will be described and critically analyzed, whereby the shortfalls in design will be highlighted and improvements shown. Some of the equipment, such as the plasma laser deposition system, the lithography system and the test facility existed before and has been modified. Newly designed systems were built to further improve the quality of our thin film superconductors; these include the inverted cylindrical magnetron (ICM) sputtering system, the argon ion mill and the incandescent substrate heater. Finally, the results of the improved thin films and structures will be shown. To summarize: The entire process was analyzed and upgraded, resulting in an improved device manufacturing facility. / AFRIKAANSE OPSOMMING: Die nano-era het aangebreek en nanotegnologie is tans een van die mees aktiewe en diverse navorsingsvelde wat wetenskaplikes wêreldwyd ontgin - hoofsaaklik as gevolg van nuwe verskynsels op molekulêre en atomiese vlak. In die nanotegnologie-navorsingsveld is die vereiste dat daar voortdurend meer effektiewe metodes gevind moet word om die al hoe meer miniatuurwordende elektroniese meganismes met verbeterde energieverbruik, spoed en ruimtebesparende vermoëns tot stand te bring. Dit is duidelik dat in hierdie toonaangewende navorsingsveld, waar tegnologiese ontwikkeling voorturend en snelgroeiend is, dit dikwels vinniger is om reeds bestaande toerusting aan te pas en te moderniseer ten einde in pas te bly met nuutontwikkelde en ontwikkelende tegnologieë. Die doel van die werk verrig, wat hier beskryf word, was om 'n nuwe deponeerstelsel, sowel as 'n droogets stelsel te bou. Bestaande apparaat is opgradeer deur verandering aan te bring. Die uiteintelikke doel is die vervaarding van beter nano-strukture, en terselfde tyd om kostes te bespaar. Nuwe stelsels en toerusting is gebou om tred te hou met tegnologiese vooruitgang. Om die belangrikheid van die verskillende tipes toerusting wat in die vervaardiging van dunlaag- supergeleierlae gebruik word te verstaan, sal 'n oorsig van die volledige vervaardigingsproses van 'n Josephson-patroon gegee word. Die apparaat wat gebruik is, sal beskryf en krities ontleed word en die tekorte in ontwerp sal uitgelig word, terwyl verbeterings aangetoon sal word. Sommige van die toerusting het voorheen bestaan en is aangepas, byvoorbeeld die plasmalaser-neerleggingstelsel, die litografiestelsel en die toetsfasiliteit. Nuwe ontwerpstelsels is gebou om die gehalte van ons dunlaagsupergeleiers verder te verbeter. Dit sluit die silindriese plasma deponeer stelsel, die Argon-ioon bron en die substraatverwarmer in. In hierdie tesis word daar eerstens 'n oorsig gegee van die totstandkomingsproses van 'n supergeleier kwantum-interfensiemeganisme, beginnende met dunlaagneerslag van YBCO (Yttrium, Barium en Koperoksied). Die oorsig word gevolg deur 'n stap-virstap beskrywing van elke daaropvolgende proses wat lei tot die voltooiing van die meganisme. Daarna word die toetsprosedure van die dunlaag en instrumente verduidelik. Bykomende veranderinge wat aan bestaande instrumente aangebring is (ten einde die dunfilmlae te verbeter en die toetsfasiliteit op te gradeer) word ook bespreek. Daar sal ook verwys word na artikels wat in verskeie joernale verskyn het oor die vernuwende aanpassings en sisteme wat in hierdie tesis verduidelik word. Ten slotte sal die resultate van die verbeterde dunlae en strukture getoon word. Kortom: die hele proses is ontleed en opgegradeer om 'n verbeterde apparaatvervaardigingsfasiliteit tot gevolg te hê.

Made available in DSpace on 2014-06-11T19:35:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-08-09Bitstream added on 2014-06-13T20:07:27Z : No. of bitstreams: 1 pereira_alj_dr_bauru.pdf: 5282854 bytes, checksum: ce33659a03b871de70411c643f913412 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A busca por um melhor entendimento da inter-relação entre os parâmetros envolvidos no processo de crescimento de filmes de dióxido de titânio (Tio2) e as propriedades estruturais, eletrônicas e magnéticas resultantes foi a principal motivação deste trabalho. Para isso, filmes Ti)2 foram crescidos usando a técnica de RF magnetron sputtering em diferentes condições. Um primeiro conjunto de filmes de Ti)2 não dopados foi depositado com fluxo contínuo de O2. Em outro conjunto, utilizou-se sistemáticas interrupções no fluxo de O2 durante a deposição. O último grupo de amostras foi depositado usando fluxo contínuo O2 e dopagem com Mn. Os filmes do primeiro grupo apresentaram morfologia colunar com estrutura majoritariamente anatase e com gap óptico de ~3,3 eV, independente da temperatura dos substratos (450ºC e 600ºC) e da razão Ar/O2 utilizada. A diminuição do fluxo de O2 provocou um aumento da absorção sub-gap que foi associada a um aumento dos defeitos eletrônicos no material. Um tratamento térmico em vácuo a 800ºC, realizado sobre filmes de TiO2 puros, revelou um aumento da fração rutila e da absorção óptica, o que também foi associado a um aumento da concentração de defeitos eletrônicos. A análise dos filmes onde o fluxo de oxigênio foi sistematicamente interrompido durante a deposição mostrou que o aumento no número de interrupções não interferiu significativamente na morfologia colunar dos filmes, mas produziu um considerável aumento na fração rutila dos filmes, bem como um aumento na absorção óptica sub-gap. O aumento na absorção na região do visível e infravermelho próximo foi atribuído a um aumento na concentração de defeitos que, de acordo com cálculos baseados na teoria do funcional da densidade, estão relacionados a estados de energia provenientes de vacâncias de oxigênio. Os filmes de TiO2 dopados com diferentes concentrações de Mn pertencentes ao terceiro grupo também / The search for a better understanding of the interrelation between the parameters involved in the process of film growth and the resulting structural, electronic and magnetic properties was the main motivation of this work. To the purpose, TiO2 films were grown by RF magnetron sputtering technique in different conditions. In a first set, TiO2 films were deposited with continuous O2 flow. In another set, systematic interruptions in the O2 flow were performed during the deposition. The last group of samples was deposited using a continuous O2 flow and Mn doping. A detailed analysis of the first group showed that these films exhibit columnar morphology with mainly anatase structure and optical gap of ~3.3eV, independent of the substrate temperature (450ºC and 600ºC) and the ratio used. THe decrease in O2 flux caused an increase in the sug gap absorption which associated with the increase in electronic defects of the material. Anneling in vacuum at 800ºC performed on pure TiO2 films showed an increase in the rutilo fraction, a red shift of the optical absorption edge, and an increase of the sub gap absorption associated with the increase of the electronic defects. The analysis of the films were the O2 flow was systematically interrupted during the deposition showed that the increase in the number of interruptions did not interfere significantly in the columnar morphology, but produced a significant increase in the fraction of rutile and brookite as well as an increase in sub-gap absorption. The increase in absorption in the visible and near infrared was attributable to an increase in the concentration of defects that, according to calculations based on the density functional theory, should be related to energy states provides by O vacancies. The Mn doped films also present a compact columnar morphology and a strong and systematic favoring of the rutile... (Complete abstract click electronic access below)