Thesis (Ph. D.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 165-173). Also available on the World Wide Web.

Thesis (M.S.)--Boise State University, 2009. / Title from t.p. of PDF file (viewed June 1, 2010). Includes abstract. Includes bibliographical references (leaves 124-131).

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 67-72). Also available on the World Wide Web.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 116-123).

Thesis (M.S.)--Rochester Institute of Technology, 1992. / Typescript. Includes bibliographical references (leaves 65-68).

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 2014-06-11T19:28:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2005Bitstream added on 2014-06-13T19:16:39Z : No. of bitstreams: 1 rodrigues_fp_me_guara.pdf: 4184618 bytes, checksum: edb4c6c9b5b186971c9e548252d87136 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / Problemas com a resistência de união metal-cerâmica têm sido encontrados quando o titânio é utilizado em Odontologia. A proposta deste estudo foi aumentar a resistência na interface titânio-cerâmica pela aplicação de um filme fino de platina na superfície do titânio, por meio da utilização da técnica de deposição por pulverização catódica. Dez padrões (1.0 x 4.0 x 30 mm) foram obtidos por meio de cortes de placas de resina acrílica e incluídos em um revestimento à base de zircônia. As fundições de titânio para preenchimento dos moldes foram realizadas em uma máquina de fundição centrífuga. As amostras foram lixadas até as dimensões finais (0.50 x 3.0 x 30 mm) para a remoção da camada -case e jateadas com pó de alumina (grupo controle) e de dióxido de titânio (grupo experimental). Uma cerâmica de ultrabaixa temperatura de fusão foi aplicada no centro da superfície (8.0 x 1.0 x 3 mm). A resistência de união foi determinada pelo teste de flexão de três pontos em uma máquina universal de ensaios com uma velocidade de 0,5mm/min. As amostras foram analisadas por meio de microscopia óptica e microscopia eletrônica de varredura antes e após os ensaios mecânicos. Os resultados revelaram valores maiores de união entre o titânio e a cerâmica quando o filme de platina foi aplicado (25,70 l 4,54 MPa), mas não houve diferença estatística significante em relação ao grupo controle (24,32 l 3,11 MPa), o que indica que o primeiro grupo também possui uma resistência de união suficiente para uso clínico. / Problems with metal-ceramic bond strength have been encountered when titanium is used in prosthetic dentistry. The purpose of this study was increase the bond strength of titanium-ceramic interface applying a platinum film on the titanium surface using DC-sputtering deposition technique. Ten 1.0 x 4.0 x 30 mm patterns were cut from sheet of acrylic resin and invested in a zirconia-based investment material. Titanium castings were made using a centrifugal casting machine. Specimens were grinded to final dimensions (0.50 x 3.0 x 30 mm) to remove the -case layer and blasted with alumina (control group) and titanium dioxide (experimental group) powders. An ultra low-fusing dental ceramic was applied to the center of the surface (8.0 x 1.0 x 3 mm). The bond strength was determined by three-point bending test. at a universal testing machine with a loading rate of 0,5mm/min.The samples were analyzed using Optical Microscopy and Scanning Electron Microscopy before and after the mechanical testing.The results showed greater values of adherence between titanium and ceramic when the platinum film was applied (25,70 l 4,54 MPa), but there were no statistic differences to those of the controls (24,32 l 3,11 MPa) that indicates that the first one has also sufficient bond strength for clinical use.

abstract: The object of this study is to investigate and improve the performance/stability of the flexible thin film transistors (TFTs) and to study the properties of metal oxide transparent conductive oxides for wide range of flexible electronic applications. Initially, a study has been done to improve the conductivity of ITO (indium tin oxide) films on PEN (polyethylene naphthalate) by inserting a thin layer of silver layer between two ITO layers. The multilayer with an optimum Ag mid-layer thickness, of 8 nm, exhibited excellent photopic average transmittance (~ 88 %), resistivity (~ 2.7 × 10-5 µ-cm.) and has the best Hackee figure of merit (41.0 × 10-3 Ω-1). The electrical conduction is dominated by two different scattering mechanisms depending on the thickness of the Ag mid-layer. Optical transmission is explained by scattering losses and absorption of light due to inter-band electronic transitions. A systematic study was carried out to improve the performance/stability of the TFTs on PEN. The performance and stability of a-Si:H and a-IZO (amorphous indium zinc oxide) TFTs were improved by performing a systematic low temperature (150 °C) anneals for extended times. For 96 hours annealed a-Si:H TFTs, the sub-threshold slope and off-current were reduced by a factor ~ 3 and by 2 orders of magnitude, respectively when compared to unannealed a-Si:H TFTs. For a-IZO TFTs, 48 hours of annealing is found to be the optimum time for the best performance and elevated temperature stability. These devices exhibit saturation mobility varying between 4.5-5.5 cm2/V-s, ION/IOFF ratio was 106 and a sub-threshold swing variation of 1-1.25 V/decade. An in-depth study on the mechanical and electromechanical stress response on the electrical properties of the a-IZO TFTs has also been investigated. Finally, the a-Si:H TFTs were exposed to gamma radiation to examine their radiation resistance. The interface trap density (Nit) values range from 5 to 6 × 1011 cm-2 for only electrical stress bias case. For "irradiation only" case, the Nit value increases from 5×1011 cm-2 to 2×1012 cm-2 after 3 hours of gamma radiation exposure, whereas it increases from 5×1011 cm-2 to 4×1012 cm-2 for "combined gamma and electrical stress". / Dissertation/Thesis / Ph.D. Materials Science and Engineering 2011