Charge trapping dynamics in Si/SiO2/Hf(1-x)SixO2 and III-V film stack systems are characterized using spectroscopic ellipsometry (SE) and second harmonic generation (SHG). For the first time, discrete absorption features within the bandgap of the SiO2 interfacial layer are identified using SE, and their relation to both intrinsic and process-induced defects is proposed. Sensitivity of the absorption features to process conditions is demonstrated and evidence that these defects contribute to Vfb roll-off is presented. Defects in the Hf(1-x)SixO2 films are probed with fs laser-induced internal multi-photon photo-excitation (IMPE) and time dependent electrostatic field induced second harmonic (TD-EFISH) generation. For the as deposited HfO2 films, a unique TD-EFISH response is identified and explained by resonant two photon ionization of a specific point defect and subsequent tunneling of the photoelectrons to the Si substrate. Charge trapping kinetics for all Hf(1-x)SixO2 films are investigated. Two characteristic trap cross sections are identified and found to be insensitive to dielectric film and process conditions, and associated with a surface “harpooning” mechanism. EFISH from non-centrosymmetric III-V media, including GaAs and In0.53Ga0.47As, is also studied. The anisotropic and time dependent SHG response from different chemically treated In0.53Ga0.47As surfaces is clearly distinguishable and associated with a process-induced change in the surface depletion field. / text

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.