Amorphous a-SiNx (:H) films have been prepared by radio-frequency sputtering in an argon-nitrogen-hydrogen atmosphere. Both hydrogenated and non-hydrogenated films were studied along with films prepared by the glow-discharge decomposition of a gaseous mixture of silane and ammonia. Photoemission experiments were performed on the sputtered samples. The position and strength of the core levels were determined, along with the plasma energies as a function of x. A comprehensive study of the number and types of defects present within a-SiN(:H) was undertaken. Films sputtered at room temperature and at 200°C, both with and without hydrogen, were studied along with films prepared by the glow-discharge technique. The results obtained are discussed in the light of existing models. Certain characteristic energies obtainable from optical data have been found for hydrogenated and non-hydrogenated films. These results are then related to other experimental results, in particular those from photoemission measurements. Reflection measurements have been made in the range 0.5eV to 12eV on the sputtered and glow-discharge films. From the reflection measurements e2 spectra were determined by Kramers-Kronig analysis. The dependence of the optical joint density of states with alloying was found from the data. It was found from these measurements that the top of the valence band gradually changes from Si3p states to N 2p states.

Silicon nitride (Si3N4) is a potentially good ceramic material for industrial heat exchangers. However, at elevated temperatures and in coal combustion atmospheres its lifetime is severely reduced by oxidation. To increase its corrosion resistance, the formation of a protective oxidation barrier layer was promoted by the deposition of oxide thin films. Homogeneous and crack-free oxide coatings of calcium magnesium zirconium phosphate (CMZP) and magnesium doped aluminum titanate (Mg-doped Al2TiO5) were successfully deposited on Si3N4 using the sol-gel and dip-coating technique. Coated and uncoated samples were then exposed to a sodium containing atmosphere at 1000*C for 360 hours to simulate typical industrial environment conditions. Structural post-exposure analyses based on weight loss measurements and mechanical tests indicated better corrosion resistance and strength retention for CMZP coated Si3N4 compared to as received and Mg-doped Al2TiO5 coated Si3N4. This difference was attributed to the protective nature of the corrosion layer, which in the case of CMZP, significantly impeded the inward diffusion of oxygen to the Si3N4 surface. / Master of Science

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by Yun-hung Ng. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references. / Text in English; abstracts in English and Chinese. / by Yun-hung Ng. / Abstract --- p.ii / 論文摘要 --- p.iii / Acknowledgements --- p.iv / Table of Contents --- p.v / List of Figures --- p.ix / List of Tables --- p.xi / Chapter Chapter 1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- Background of Study --- p.1 / Chapter 1.2 --- General Properties of a-SiNx and a-SiOxNy --- p.1 / Chapter 1.3 --- Common Preparation Methods of a-SiNx and a-SiOxNy --- p.2 / Chapter 1.4 --- Applications of a-SiNx in Microelectronics --- p.4 / Chapter 1.5 --- Applications of a-SiOxNy in Microelectronics --- p.6 / References --- p.8 / Chapter Chapter 2 --- METHODOLOGY --- p.10 / Chapter 2.1 --- Introduction --- p.10 / Chapter 2.2 --- Mott Rule --- p.10 / Chapter 2.3 --- Random Mixture Model --- p.11 / Chapter 2.4 --- Random Bonding Model --- p.12 / Chapter 2.5 --- Hasegawa Model --- p.15 / References --- p.20 / Chapter Chapter 3 --- INSTRUMENTATION --- p.21 / Chapter 3.1 --- X-ray Photoelectron Spectroscopy (XPS) --- p.21 / Chapter 3.1.1 --- Fundamental Theory of XPS --- p.21 / Chapter 3.1.2 --- Qualitative Analysis using XPS --- p.25 / Chapter 3.1.2.1 --- Chemical Shift --- p.25 / Chapter 3.1.2.2 --- Angular Effect on XPS --- p.28 / Chapter 3.1.2.3 --- Valence Band Investigation --- p.28 / Chapter 3.1.3 --- Quantitative Analysis using XPS --- p.30 / Chapter 3.1.4 --- Instrumental Setup of XPS --- p.33 / Chapter 3.2 --- Ultraviolet Photoelectron Spectroscopy --- p.37 / Chapter 3.2.1 --- Basic Theory of UPS --- p.37 / Chapter 3.2.2 --- Instrumentation --- p.38 / References --- p.41 / Chapter Chapter 4 --- SHORT RANGE ORDER OF a-SiNx --- p.42 / Chapter 4.1 --- Sample Preparation --- p.42 / Chapter 4.2 --- XPS Analysis of a-SiNx --- p.43 / Chapter 4.2.1 --- Angle Resolved XPS Analysis --- p.43 / Chapter 4.2.2 --- RB Model and RM Model Simulation of a-SiNx --- p.43 / Chapter 4.2.3 --- Intermediate Mixture (IM) Model --- p.50 / Chapter 4.2.4 --- Valence Band Structure of a-SiNx --- p.51 / Chapter 4.3 --- Raman Measurements --- p.54 / Chapter 4.4 --- Photoluminescence of a-SiNx --- p.54 / Chapter 4.5 --- Large Scale Potential Fluctuations in a-SiNx --- p.56 / Chapter 4.6 --- Conclusion --- p.61 / References --- p.62 / Chapter Chapter 5 --- MOTT RULE VERIFICATION OF a-SiOxNy --- p.65 / Chapter 5.1 --- Sample Preparation --- p.65 / Chapter 5.2 --- Validity of Mott Rule on a-SiOxNy --- p.66 / Chapter 5.3 --- Conclusion --- p.73 / References --- p.74 / Chapter Chapter 6 --- SHORT RANGE ORDER OF a-SiOxNy --- p.75 / Chapter 6.1 --- Angle Resolved XPS Analysis --- p.75 / Chapter 6.2 --- Random Bonding Model Simulation of a-SiOxNy --- p.75 / Chapter 6.3 --- Conclusion --- p.79 / References --- p.82 / Chapter Chapter 7 --- CONCLUSIONS --- p.83

In this study, the characteristics of low-pressure chemical vapor deposition deposited silicon nitride films on n-GaN substrate were investigated. The physical and chemical properties were measured and surveyed. And an Al/LPCVD-Si3N4/n-GaN MOS structure was used for the electrical characterizations. For the electrical property improvements, we investigated the low-pressure chemical vapor deposition deposited silicon nitride films by (NH4)2Sx treatment. Furthermore, the silicon nitride films were passivated by fluorine ions to improve the electrical characterizations that came from the liquid phase deposited SiO2 stacks. After the (NH4)2Sx treatment and fluorine ions passivation, the dielectric constant of low-pressure chemical vapor deposition deposited silicon nitride films were maintained and the leakage current density were improved. The highest dielectric constant is 12.13, and lowest leakage current density are 1.73¡Ñ10-10 A/cm2 at 1 MV/cm and 3.81¡Ñ10-10 A/cm2 at 1 MV/cm for the LPCVD-Si3N4 film after fluorine passivation and (NH4)2Sx treatment.

Thesis (M.S.)--University of Texas at El Paso, 2009. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Thesis (Ph. D.)--Rutgers University, 2008. / "Graduate Program in Ceramic and Materials Science and Engineering." Includes bibliographical references (p. 213-218).

Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains vii, 30 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 28-30).

Philosophiae Doctor - PhD / Nanocrystalline silicon (nc-Si:H) is an interesting type of silicon with superior electrical properties that are more stable compared to amorphous silicon (a-Si:H). Silicon nitride (SiNₓ) thin films are currently the dielectric widely applied in the microelectronics industry and are also effective antireflective and passivating layers for multicrystalline silicon solar cells. Research into the synthesis and characterization of nc-Si:H and SiNₓ thin films is vital from a renewable energy aspect. In this thesis we investigated the film growth mechanisms and the filament stability during the hot-wire chemical vapour deposition (HWCVD) of nc-Si:H and SiNₓ thin films. During the HWCVD of nc-Si:H, electron backscatter diffraction (EBSD) revealed that the tantalum (Ta) filament aged to consists of a recrystallized Ta-core with Ta-rich silicides at the hotter centre regions and Si-rich Ta-silicides at the cooler ends nearer to the electrical contacts. The growth of nc-Si:H by HWCVD is controlled by surface reactions before and beyond the transition from a-Si:H to nc-Si:H. During the transition, the diffusion of hydrogen (H) within the film is proposed to be the reaction controlling step. The deposition pressure influenced the structural, mechanical and optical properties of nc-Si:H films mostly when the film thickness is below 250 nm. The film stress, optical band gap, refractive index and crystalline volume fraction approached similar values at longer deposition times irrespective of the deposition pressure. Filament degradation occurred during the HWCVD of SiNₓ thin films from low total flow rate SiH₄ / ammonia (NH₃) / H₂ gas mixture. Similar to the HWCVD of nc-Si:H, the Ta-core recrystallized and silicides formed around the perimeter. However, Tanitrides formed within the filament bulk. The extent of nitride and silicide formation, porosity and cracks were all enhanced at the hotter centre regions, where filament failure eventually occurred. We also applied HWCVD to deposit transparent, low reflective and hydrogen containing SiNₓ thin films at total gas flow rates less than 31 sccm with NH₃ flow rates as low as 3 sccm. Fluctuations within the SiNₓ thin film growth rates were attributed to the depletion of growth species (Si, N, and H) from the ambient and their incorporation within the filament during its degradation.

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