Thesis advisor: Kian L. Tan / Thesis advisor: Dunwei Wang / Silicon nanowires are utilized to harvest the energy from visible light. The introduction of a nickel pre-catalyst, 1, allows for this energy to be stored in chemical bonds, which are subsequently used in the carboxylation of 4-octyne. / Thesis (MS) — Boston College, 2014. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Nos últimos anos tem se dado uma evolução muito grande na área industrial de MEMS, e esta se caracteriza por desenvolvimento dos processos de microeletrônica para diminuição de custos e a própria integração de diferentes sistemas que passam a ser muito confiáveis em diferentes aplicações. Motivado pelas tendências de elevar os conhecimentos de processos para obtenção de MEMS, foi proposto um trabalho de corrosão anisotrópica de silício utilizando solução de hidróxido de potássio (KOH) junto com a adição de sais metálicos. O objetivo é comprovar o efeito de compensação cinética da reação e a influência destes metais no caráter anisotrópico e nas taxas de corrosão. Foi analisado o efeito de zinco, alumínio e cobre, e puderam ser observadas alterações nas taxas de corrosão e, conseqüentemente, nas geometrias resultantes no corpo de silício. Com a caracterização dessas mudanças comprovou-se suposições anteriores de que o efeito de compensação cinética encontrado na síntese direta de dimetilclorosilana (DMDCS) e silício, também ocorreria para a corrosão de silício em KOH, pois esses processos obedecem a lei de Arrhenius e tem um comportamento anisotrópico em silício. Os resultados obtidos, graças a um grande detalhamento de todos as etapas de processo e caracterização voltada à tecnologia do silício, comprovaram as suposições teóricas e mostraram como pode ser modificada a taxa de corrosão na anisotropia com a adição de metais em solução. / In the past few years it has been a huge evolution in industrial area of MEMS, and this one is characterized by the development of the processes of microelectronic to reduce cost and to integrate different systems that become very trustful in different applications. It is being done a work in silicon anisotropic etching in Potassium hydroxide (KOH) added with metallic impurities aiming the study of the kinetic compensation effect and the influence of these metals in the anisotropy and in etch rates. It was analyzed the effects of Zinc, Aluminum and Cupper and it could be observed changes in etch rates, and, consequently, in the resulting geometries. After characterization of theses changes it was proved that previous suppositions that the kinetic compensation effects found in direct synthesis of dimethyldichorosilane (DMDCS) and silicon would also occur for silicon anisotropic etching in KOH, due to both reactions follows Arrhenius law and are anisotropic reactions. The obtained results proved the theory suppositions that the etch rate and anisotropy can be modified when adding metals to the solution.

Neste trabalho são apresentados resultados da caracterização estrutural e morfológica de filmes de oxinitreto de silício (SiOxNy) depositados pela técnica de deposição química a vapor assistida por plasma (PECVD) a baixa temperatura (320°C). O objetivo deste trabalho é relacionar a composição química de ligas amorfas de SiOxNy com suas propriedades ópticas, estruturais, morfológicas e mecânicas visando sua aplicação em dispositivos elétricos, optoeletrônica e microestruturas. A proposta é dar continuidade a trabalhos prévios desenvolvidos no grupo, que demonstraram a viabilidade de controlar a composição química e, como conseqüência, controlar as propriedades como o índice de refração, constante dielétrica e fotoluminescência de filmes de SiOxNy. As condições de deposição foram ajustadas de forma a obter dois tipos de material: filmes de SiOxNy de composição química controlável entre a do SiO2 e a do de Si3N4 e filmes de SiOxNy com composição rica em Si. O material foi caracterizado pelas técnicas de elipsometria, índice de refração por prisma acoplado, RBS (Rutherford Backscattering Spectroscopy), FTIR (Fourier Transform Infrared Spectroscopy), XANES (X-Ray Absorption Near Edge Spectroscopy) na borda K do Si, O e N, medida de stress residual e microscopia eletrônica de varredura (Scanning Electron Microscopy) e de transmissão (Transmission Electron Microscopy). Os resultados mostraram que os filmes com composição química intermediária entre a do SiO2 e a do Si3N4 apresentam arranjo estrutural estável com a temperatura, mantendo as ligações e a estrutura amorfa mesmo após tratamentos térmicos a 1000°C. Também fora demonstrada a possibilidade de obter um material com baixo stress residual e índice de refração ajustável entre 1,46 e 2, resultados ótimos para aplicações em MOEMS (micro-opto-electro- mechanical systems). Já nas amostras ricas em Si foi observada a formação de diferentes fases, sendo uma delas formada por aglomerados de Si e a outra por material constituído por uma mistura de ligações Si-O e Si-N. Este material apresenta a formação de nanocristais de Si, dependendo do conteúdo de Si e das condições do tratamento térmico, permitindo assim, sua aplicação em dispositivos emissores de luz. / In this work results on the morphological and structural characterization of silicon oxynitride (SiOxNy) films deposited by plasma enhanced chemical vapor deposition technique (PECVD) at low temperature (320°C) are presented. The main goal is to correlate the chemical composition of amorphous SiOxNy alloys to their optical, structural, morphological and mechanical properties intending applications on electrical, optoelectronic and micromechanical devices. The proposal is to continue previous research developed in this group, which demonstrated the possibility of tuning the chemical composition and, consequently, the SiOxNy films properties such as refractive index, dielectric constant and photoluminescence by the precise control of the deposition parameters. The deposition conditions were adjusted in order to obtain to material types, SiOxNy films with tunable chemical composition between SiO2 and Si3N4 and silicon-rich SiOxNy. The characterization was performed by elipsometry, refractive index by coupled prism, RBS (Rutherford Backscattering Spectroscopy), FTIR (Fourier Transform Infrared Spectroscopy), XANES (X-Ray Absorption Near Edge Spectroscopy) on K edge of Si, O and N, residual stress measurement and Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The films with chemical composition between SiO2 and Si3N4 presented stable structural arrangement with temperature, maintaining the chemical bonds and the amorphous structure after high temperature annealing. Also the results demonstrated the possibility of producing a low residual stress material and an adjustable refractive index since in the 1.46 to 2 range, excellent result for MOEMS devices (micro-opto-electro- mechanical systems applications. For silicon rich-samples the formation of different phases was observed, one formed by Si clusters and other one by a mixture of Si-O and Si-N bonds. Depending on the Si content and on the annealing conditions this material can present nanocristals, results which allowed us to understand and to optimize this material for light emitting devices applications.

Lau Shing-tat. / Chinese title: / Bibliography: leaves 129-130 / Thesis (M.Phil.)--Chinese University of Hong Kong, 1983

by Wah-chung Wong. / Thesis (M.Ph.)--Chinese University of Hong Kong, 1987. / Bibliography: leaves 155-162.

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

Chan Siu-pang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 45-47). / Abstract also in Chinese. / TITLE PAGE --- p.i / THESIS COMMUTE --- p.ii / ABSTRACT (English) --- p.iii / ABSTRACT (Chinese) --- p.iv / ACKNOWLEDGMENT --- p.v / TABLE OF CONTENTS --- p.vi / LIST OF FIGURES --- p.vii / LIST OF TABLES --- p.viii / Chapter CHAPTER 1. --- Introduction --- p.1 / Chapter Section 1.1. --- General Introduction --- p.1 / Chapter Section 1.2. --- Background Information --- p.2 / Chapter 1.2.1. --- Si(100) Surface --- p.2 / Chapter 1.2.2. --- Structure of Cl/Si(100) --- p.7 / Chapter Section 1.3. --- Etching of Si(100) by Chlorine --- p.9 / Chapter Section 1.4. --- Theory --- p.14 / Chapter Section 1.5. --- Computational Model --- p.17 / Chapter CHAPTER 2. --- Desorption Mechanism of SiCl4 --- p.19 / Chapter Section 2.1. --- Desorption Mechanism --- p.19 / Chapter 2.1.1. --- Trajectory1 --- p.20 / Chapter 2.1.2. --- Trajectory2 --- p.23 / Chapter 2.1.3. --- Trajectory3 --- p.26 / Chapter 2.1.4. --- Trajectory4 --- p.29 / Chapter 2.1.5. --- Trajectory5 --- p.32 / Chapter 2.1.6. --- Trajectory6 --- p.35 / Chapter Section 2.2. --- Discussion --- p.38 / Chapter Section 2.3. --- Conclusion --- p.44 / REFERENCES: --- p.45

Liang Tak Keung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references. / Abstracts in English and Chinese. / Abstract --- p.I / Acknowledgement --- p.IV / Table of contents --- p.V / List of figures --- p.VIII / Chapter Chapter 1: --- Introduction --- p.1 / Chapter 1.1 --- Introduction to silicon waveguides --- p.2 / Chapter 1.2 --- Introduction to characterization of silicon waveguides --- p.5 / Chapter 1.3 --- Introduction to applications of silicon waveguides --- p.6 / Chapter 1.4 --- Introduction to chapters --- p.7 / References --- p.9 / Chapter Chapter 2: --- Modal analysis of the single-mode silicon waveguide --- p.12 / Chapter 2.1 --- Waveguide structure --- p.13 / Chapter 2.2 --- Effective Index Method --- p.14 / Chapter 2.3 --- Silicon waveguide modal analysis --- p.20 / Chapter 2.4 --- Conclusion --- p.25 / References --- p.26 / Chapter Chapter 3: --- Optical dispersion --- p.27 / Chapter 3.1 --- Introduction --- p.28 / Chapter 3.1.1 --- Chromatic dispersion --- p.28 / Chapter 3.1.2 --- Polarization-mode dispersion --- p.33 / Chapter 3.2 --- Review of dispersion measurement technique --- p.35 / Chapter 3.2.1 --- Chromatic dispersion measurement --- p.35 / Chapter 3.2.2 --- Polarization-mode dispersion measurement --- p.39 / Chapter 3.3 --- Measurement of chromatic dispersion in silicon waveguide --- p.40 / Chapter 3.3.1 --- Experimental setup --- p.40 / Chapter 3.3.2 --- Measurement theory --- p.41 / Chapter 3.3.3 --- Results and discussions --- p.43 / Chapter 3.4 --- Measurement of polarization-mode dispersion in silicon waveguide --- p.49 / Chapter 3.4.1 --- Experimental setup --- p.49 / Chapter 3.4.2 --- Simulation results --- p.50 / Chapter 3.4.3 --- Results and discussions --- p.51 / Chapter 3.5 --- Conclusion --- p.53 / References --- p.54 / Chapter Chapter 4: --- Nonlinear properties --- p.56 / Chapter 4.1 --- Introduction --- p.57 / Chapter 4.1.1 --- Nonlinear refractive index (optical Kerr effect) --- p.57 / Chapter 4.1.2 --- Self-phase modulation --- p.58 / Chapter 4.1.3 --- Two-photon absorption --- p.59 / Chapter 4.1.4 --- Impact of nonlinearities on waveguides --- p.60 / Chapter 4.2 --- Measurement of nonlinear refractive index n2 and TPA coefficient β2 --- p.61 / Chapter 4.2.1 --- Nonlinear refractive index (n2) --- p.62 / Chapter 4.2.2 --- TPA coefficient (β2) --- p.63 / Chapter 4.2.3 --- Conclusion --- p.65 / References --- p.66 / Chapter Chapter 5: --- Loss in ion-implanted silicon waveguide --- p.67 / Chapter 5.1 --- Introduction to ion implantation --- p.68 / Chapter 5.2 --- Ion-implantation process --- p.70 / Chapter 5.3 --- Loss measurement by Fabry-Perot interferometer --- p.72 / Chapter 5.4 --- Results and discussions --- p.73 / References --- p.75 / Chapter Chapter 6: --- Silicon waveguide autocorrelator --- p.76 / Chapter 6.1 --- Introduction on SHG and waveguide autocorrelation technique --- p.77 / Chapter 6.2 --- Theory of TPA absorption --- p.79 / Chapter 6.3 --- Two-photon-induced photocurrent in silicon waveguide --- p.80 / Chapter 6.3.1 --- Device structure --- p.80 / Chapter 6.3.2 --- Intensity dependent photocurrent generation --- p.81 / Chapter 6.3.3 --- Theoretical modeling of photocurrent generation --- p.83 / Chapter 6.4 --- Autocorrelation measurement of short pulses --- p.87 / Chapter 6.4.1 --- Experimental setup --- p.87 / Chapter 6.4.2 --- Results and discussions --- p.88 / Chapter 6.5 --- Conclusion --- p.92 / References --- p.93 / Chapter Chapter 7: --- Conclusion and future works --- p.94 / Chapter 7.1 --- Conclusion --- p.94 / Chapter 7.2 --- Future works --- p.95 / Appendices --- p.96 / Appendix A: Silicon waveguide fabrication process capability at CUHK --- p.96 / Appendix B: Matlab programs of EIM and TPA calculation --- p.100 / Appendix C: Publications list --- p.104

Chong Yuen Tung = 硅化鐵薄膜的相和微觀結構 / 莊宛曈. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 63-65). / Text in English; abstracts in English and Chinese. / Chong Yuen Tung = Gui hua tie bo mo de xiang he wei guan jie gou / Zhuang Wantong. / Abstract --- p.i / 摘要 --- p.ii / Acknowledgment --- p.iii / Table of contents --- p.iv / List of Figures --- p.viii / List of Tables --- p.x / Chapter CHAPTER 1: --- Introduction --- p.1 / Chapter CHAPTER 2: --- Background --- p.4 / Chapter 2.1 --- Phases of crystalline FeSi2 --- p.4 / Chapter 2.2 --- Electronic structure of β-FeSi2 --- p.7 / Chapter 2.3 --- Orientation relationship between β-FeSi2 and Si --- p.8 / Chapter CHAPTER 3: --- Instrumentation --- p.10 / Chapter 3.1 --- Metal vapor vacuum arc ion source implantation --- p.10 / Chapter 3.2 --- Rutherford backscattering --- p.12 / Chapter 3.3 --- Transmission Electron Microscopy (TEM) --- p.13 / Chapter 3.3.1 --- Principles of TEM --- p.13 / Chapter 3.3.2 --- Electron specimen interaction and contrast --- p.14 / Chapter 3.3.3 --- Electron Diffraction --- p.15 / Chapter 3.3.4 --- Sample Preparation --- p.17 / Chapter 3.3.4.1 --- Plan-view sample --- p.17 / Chapter 3.3.4.2 --- Cross-section sample --- p.17 / Chapter CHAPTER 4: --- FeSi2 films fabricated by ion implantation --- p.18 / Chapter 4.1 --- Introduction --- p.18 / Chapter 4.2 --- Experimental details --- p.18 / Chapter 4.3 --- Ion energy series --- p.19 / Chapter 4.3.1 --- As-implanted sample --- p.19 / Chapter 4.3.1.1 --- Results --- p.20 / Chapter 4.3.1.2 --- Discussions --- p.20 / Chapter 4.3.2 --- Annealed samples --- p.24 / Chapter 4.3.2.1 --- Morphology of the annealed samples and the damage on Si substrate --- p.24 / Chapter 4.3.2.2 --- Identification of the FeSi2 phase and their orientation relationship with the Si matrix --- p.24 / Chapter 4.3.2.3 --- Photoluminescence of the samples --- p.26 / Chapter 4.3.2.4 --- Discussions --- p.26 / Chapter 4.4 --- Ion dosage series --- p.31 / Chapter 4.4.1 --- Results --- p.31 / Chapter 4.4.2 --- Discussions --- p.32 / Chapter 4.5 --- Summary --- p.36 / Chapter CHAPTER 5: --- Effect of post annealing on the phase and microstructure of FeSi2 --- p.37 / Chapter 5.1 --- Introduction --- p.37 / Chapter 5.2 --- Experimental details --- p.37 / Chapter 5.3 --- The correlation between microstructure of FeSi2 synthesized under different annealing conditions and their PL --- p.38 / Chapter 5.3.1 --- RTA series --- p.38 / Chapter 5.3.1.1 --- Results --- p.38 / Chapter 5.3.1.2 --- Discussions --- p.39 / Chapter 5.3.2 --- FA series --- p.42 / Chapter 5.3.2.1 --- Results --- p.42 / Chapter 5.3.2.2 --- Discussions --- p.44 / Chapter 5.3.3 --- RTAFA series --- p.45 / Chapter 5.3.3.1 --- Results --- p.45 / Chapter 5.3.3.2 --- Discussions --- p.45 / Chapter 5.4 --- The existence of alpha phase and its special shape --- p.51 / Chapter 5.4.1 --- Results --- p.51 / Chapter 5.4.2 --- Discussions --- p.52 / Chapter 5.5 --- The existence of gamma phase in 1050°C furnace annealed sample / Chapter 5.5.1 --- Results --- p.56 / Chapter 5.5.2 --- Discussions --- p.57 / Chapter 5.6 --- Summary --- p.59 / Chapter CHAPTER 6: --- Conclusions --- p.61 / References --- p.63

The following thesis is comprised of four main areas of work. These are centred around the experimental observation of phenomena associated with both linear and non-linear optics in silicon photonic-wires. As a comparison, I also discuss a similar coupled-waveguide system; dual-core hollow-core photonic crystal fibre. To introduce the reader to this work, the first chapter will recap some undergraduate level theory; a general introduction to optical waveguides. It is not intended to be a complete theoretical picture, as many beautiful texts on optics already exist [1–3]. This chapter concerns itself only with the aspects of optics with which the author was intimately aware of throughout the completion of this thesis. Thereafter, the chapters become specific to the particular experiments undertaken. Each one follows a simple framework: examination of the relevant theory, extending upon that already discussed in the first chapter, a literature review and finally a discussion of the work I completed within this thesis. Chapter 2 is the only chapter not related to silicon based photonics. Here I discuss dual-core hollow-core photonic crystal fibres; including guidance mechanisms, fabrication methods and the numerical modelling techniques employed in my work. I will compare these numerical results to experimental results taken by colleagues at the university of Bath. Chapter 3 analyses linear propagation in arrays of silicon photonic wires. I extend the simple picture of light propagating in waveguides to discuss the di↵erent types of dispersion inherent in this system and how dispersion tailoring can be achieved; with reference to the other literature on this topic. Experimental results are examined and discussed. Chapters 4 and 5 discuss non-linear propagation in silicon photonic wire arrays; modulation instability and spatio-temporal solitons respectively. In each case I extend the ideas on non-linearity presented in Chapter 1 to explain both modulation instability and optical solitons. Detailed descriptions of the experiments undertaken, and associated numerical modelling completed are then discussed. Whilst the work I present is incomplete, I will discuss subsequent work performed by my colleagues at the University of Bath based on my initial work. Finally, Chapter 6 draws together my conclusions.