A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science in Engineering, 2017 / This research has considered an idealistic non-interleaved planar transformer wherein only the electromagnetic parasitic capacitive and inductive elements arising out of the transformer geometry are taken into account, without considering material limitations. A suitable model for the planar transformer is used to analyse its frequency and power transfer characteristics; this model was validated by three dimensional electromagnetic simulations of various planar transformer structures in FEKO simulation software. The capacitive and inductive parasitics in this model have been found to be functions of the dielectric thickness. The theoretical bandwidth for the planar transformer is defined in this research as a function of dielectric thickness. The effect of dielectric thickness of the transformer windings on the bandwidth of the transformer is analysed, based on the premise that the inherent parasitic capacitive and inductive elements would affect the transfer characteristics of the transformer. Upon conclusion of this analysis, it is found that the dielectric thickness of a planar transformer can be optimised such as to present an optimised bandwidth. A closed form analytic expression for the optimum dielectric thickness value is derived and presented in this research. In a design example of a 4:1 50W transformer presented in this research, it has been shown that the bandwidth can be improved by 384%, along with a power density improvement of 45%, upon choosing of an optimum dielectric thickness of 0.156mm to replace a standard 0.4mm thick dielectric. It should be noted that the results derived in this research are purely theoretical, justified by many idealisations and assumptions that are argued throughout the research. It is thus expected that practical results should at best approach the theoretical results, due to the known non-ideal nature of reality. / CK2018

Wang Lei. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references. / Abstracts in English and Chinese. / List of Figures --- p.vi / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Scaling issues of Metal-Oxide-Semiconductor field effect transistor --- p.1 / Chapter 1.2 --- Alternative high-k gate dielectrics --- p.4 / Chapter 1.3 --- Overview of this thesis --- p.9 / References --- p.10 / Chapter Chapter 2 --- Deposition and characterization techniques for ultrathin HfO2 films --- p.11 / Chapter 2.1 --- Introduction --- p.11 / Chapter 2.2 --- Ultrathin Hf02 Films Growth and Post Deposition Modification --- p.11 / Chapter 2.2.1 --- Ultrahigh Vacuum Electron-beam Evaporation --- p.11 / Chapter 2.2.2 --- High Concentration Ozone Annealing --- p.12 / Chapter 2.2.3 --- Plasma Immersion Ion Implantation --- p.14 / Chapter 2.2.4 --- Rapid Thermal Annealing --- p.16 / Chapter 2.3 --- Compositional Characterization Techniques --- p.17 / Chapter 2.3.1 --- X-ray Photoelectron Spectroscopy --- p.17 / Chapter 2.3.2 --- Rutherford Backscattering Spectrometry --- p.18 / Chapter 2.4 --- Structural and Surface Morphological Characterization Techniques --- p.19 / Chapter 2.4.1 --- High-Resolution Transmission Electron Microscopy --- p.19 / Chapter 2.4.2 --- Ultrahigh Vacuum Scanning Tunneling Microscopy --- p.20 / Chapter 2.4.3 --- Ultrahigh Vacuum Atomic Force Microscopy --- p.22 / Chapter 2.5 --- Electrical Characterization --- p.24 / Chapter 2.5.1 --- Capacitance-voltage (C-V) Measurement --- p.24 / Chapter 2.5.2 --- Current-voltage (I-V) Measurement --- p.25 / References --- p.26 / Chapter Chapter 3 --- Control of interfacial silicate between Hf and SiO2 by high concentration ozone --- p.27 / Chapter 3.1 --- Introduction --- p.27 / Chapter 3.2 --- Experimental procedure --- p.28 / Chapter 3.3 --- Results and discussion --- p.29 / Chapter 3.4 --- Conclusion --- p.35 / References --- p.36 / Chapter Chapter 4 --- Electrical characteristics of postdepositon annealed ultrathin Hf02 films --- p.37 / Chapter 4.1 --- Introduction --- p.37 / Chapter 4.2 --- Capacitance of gate stack in metal-insulator-semiconductor structure --- p.38 / Chapter 4.3 --- Electrical characteristics of ultrathin HfO2 films by high temperature Ozone oxidation --- p.39 / Chapter 4.4 --- Electrical and structural properties of ultrathin HfO2 films by high temperature rapid thermal annealing --- p.46 / Chapter 4.5 --- Conclusion --- p.48 / References --- p.50 / Chapter Chapter 5 --- Effect of nitrogen incorporation on thermal stability of ultrathin Hf02 films --- p.51 / Chapter 5.1 --- Introduction --- p.51 / Chapter 5.2 --- Experimental procedure --- p.52 / Chapter 5.3 --- Results and discussion --- p.52 / Chapter 5.4 --- Conclusion --- p.58 / References --- p.59 / Chapter Chapter 6 --- Local characterization of ultrathin HfO2 films by in-situ Ultrahigh Vacuum Scanning Probe Microscopy --- p.61 / Chapter 6.1 --- Introduction --- p.61 / Chapter 6.2 --- Experimental procedure --- p.62 / Chapter 6.3 --- Morphology and structure of initial growth of HfO2 --- p.63 / Chapter 6.4 --- Local characterization of ultrathin HfO2 films by in-situ UHV-STM --- p.66 / Chapter 6.5 --- UHV c-AFM study of leakage path evolution in ultrathin Hf02 films --- p.71 / Chapter 6.6 --- Conclusion --- p.72 / References --- p.73 / Chapter Chapter 7 --- Conclusion --- p.74 / Publications --- p.76

In this thesis the concept of inhomogeneous dielectrics is demonstrated for various optical coating applications. Compositionally-varying silicon oxynitride (SiON) dielectric layers, with the refractive index varying as a function of position, are grown by computer-controlled plasma-enhanced chemical vapor deposition (PECVD) using silane, nitrogen, and nitrous oxide reactant gases. Compositionally graded and superlattice-like SiON layers are grown and their compositional profiles are confirmed by Auger electron spectroscopy sputter profiling. Inhomogeneous antireflection coatings and rugate filters, with sinusoidally varying refractive index profiles, are designed and fabricated and their measured spectral responses are found to be in excellent agreement with simulated results. Alternating-current thin film electroluminescent (ACTFEL) devices with multiple layer dielectrics also are designed, fabricated, and the insulating layers are shown to increase the optical outcoupling efficiency of an ACTFEL devices by approximately 14 % compared to that of a conventional ACTFEL structure. / Graduation date: 1993

No description available.

Thesis (Ph.D.) -- McMaster University, 2000. / [Lámbdha] and [micron] in title are Greek letters. Includes bibliographical references (leaves 110-114). Also available via World Wide Web.

Thesis (Ph. D.)--University of North Texas, Dec., 2007. / Title from title page display. Includes bibliographical references.

Thesis (Ph. D.)--University of California, Riverside, 2009. / Includes abstract. Includes bibliographical references. Issued in print and online. Available via ProQuest Digital Dissertations.

The incorporation of fluorine into SiO2 has been shown to reduce the dielectric constant of the existing materials by reducing the electrical polarizability. However, the incorporation of fluorine has also been shown to decrease film stability. Therefore, new efforts have been made to find different ways to further decrease the relative dielectric constant value of the existing low-k materials. One way to reduce the dielectric constant is by decreasing its density. This reduces the amount of polarizable materials. A good approach is increasing porosity of the film. Recently, fluorinated silica xerogel films have been identified as potential candidates for applications such as interlayer dielectric materials in CMOS technology. In addition to their low dielectric constants, these films present properties such as low refractive indices, low thermal conductivities, and high surface areas. Another approach to lower k is incorporating lighter atoms such as hydrogen or carbon. Silsesquioxane based materials are among them. However, additional integration issues such as damage to these materials caused by plasma etch, plasma ash, and wet etch processes are yet to be overcome. This dissertation reports the effects of triethoxyfluorosilane-based (TEFS) xerogel films when reacted with silylation agents. TEFS films were employed because they form robust silica networks and exhibit low dielectric constants. However, these films readily absorb moisture. Employing silylation reactions enhances film hydrophobicity and permits possible introduction of this film as an interlayer dielectric material. Also, this work describes the effects of SC-CO2 in combination with silylating agents used to functionalize the damaged surface of the ash-damaged MSQ films. Ashed MSQ films exhibit increased water adsorption and dielectric constants due to the carbon depletion and modification of the properties of the low-k material caused by interaction with plasma species. CO2 is widely used as a supercritical solvent, because of its easily accessible critical point, low cost, and non-hazardous nature. Its unique diffusion and surface tension properties make SC-CO2 a good candidate for treatment of porous ultra low-k materials.

No description available.

A transmission electron microscopy study involving direct and replicating techniques is directed to a definition of the microstructure of radio frequency-sputtered, thin lead-dielectric cermet films. Once defined, this microstructure is used to obtain theoretical film refractive indices. The Maxwell Garnet theory provides a basis for the theoretical results. Measurements of film transmission and reflectivity are used to obtain rough experimental values for film refractive indices by the Tekucheva method. More exact values are obtained via ellipsometry. The rough Tekucheva values are used to determine the range over which computer calculations interpreting the ellipsometric results must be made. This technique yields accurate values for the film refractive indices. The films are radio-frequency-sputtered from lead glass targets with varying amounts of lead attached to their faces. Three different targets are used, resulting in three sets of films, each containing a different percentage of lead. The lead content of the films is measured by microprobe analysis as well as visual inspection of micrographs. The lower content lead films are seen to consist of tiny balls of lead embedded in the dielectric, as are the intermediate lead content films; but the higher lead content films form metallic networks throughout the dielectric. The lower and intermediate lead content films have indices which agree with the predictions of the Maxwell Garnett theory; but the higher lead content films, whose structure fails to conform to the Maxwell Garnett configuration, have indices whose values diverge from the Maxwell Garnett predictions. It is thus shown that the theory of Maxwell Garnett is valid for thin cermet films whose structure consists of tiny metal balls embedded in a dielectric medium. / Ph. D.