by Lo Veng Cheong. / Parallel title in Chinese characters. / Thesis (Ph.D.) -- Chinese University of Hong Kong, 1991. / Bibliography: leaves 116-119. / ACKNOWLEDGEMENT --- p.i / ABSTRACT --- p.ii / LIST OF SYMBOLS --- p.iv / LIST OF FIGURES --- p.ix / LIST OF TABLES --- p.xii / Chapter CHAPTER ONE --- INTRODUCTION --- p.1 / Chapter CHAPTER TWO --- SURVEYS ON THEORETICAL MODELS --- p.7 / Chapter 2.1 --- Some Basic Concepts --- p.7 / Chapter 2.1.1 --- Vacancy Mechanism and Interstitial Mechanism --- p.7 / Chapter 2.1.2 --- Relative Contribution from Various Point Defects Species --- p.15 / Chapter 2.1.3 --- Impurity Point Defect Pairs or 'Centers' --- p.20 / Chapter 2.1.4 --- Anomalous Diffusion --- p.21 / Chapter 2.2 --- Historical Review on Theoretical Models --- p.22 / Chapter 2.3 --- Formulation of the General Model --- p.29 / Chapter 2.3.1 --- Effects to be and Not to be Considered --- p.30 / Chapter 2.3.2 --- Derivation of the Basic Equations --- p.31 / Chapter CHAPTER THREE --- MODELING OF THE DAMAGE ENHANCED DIFFUSION OF IMPLANTED BORONS IN SILICON --- p.35 / Chapter 3.1 --- Brief Description of Powell's Experiment --- p.35 / Chapter 3.2 --- Modeling --- p.38 / Chapter 3.3 --- Results and Discussion --- p.45 / Chapter CHAPTER FOUR --- EXPERIMENTAL INVESTIGATION OF BORON DIFFUSION DIFFUSION ASSISTED BY THE NON-UNIFORMITY OF POINT DEFECTS --- p.66 / Chapter 4.1 --- Introduction --- p.66 / Chapter 4.2 --- Experimental --- p.67 / Chapter 4.3 --- Results and Discussion --- p.88 / Chapter CHAPTER FIVE --- CONCLUSION AND FURTHER SUGGESTIONS --- p.103 / Chapter 5.1 --- Conclusion --- p.103 / Chapter 5.2 --- Further Suggestions --- p.104 / Chapter APPENDIX A --- DOPANT CONCENTRATION DEPENDENCE OF THE ENHANCED DIFFUSION --- p.107 / Chapter APPENDIX B --- FLOW CHART OF NUMERICAL SIMULATION --- p.111 / REFERENCE --- p.116

published_or_final_version / Physics / Master / Master of Philosophy

No description available.

No description available.

published_or_final_version / abstract / Physics / Doctoral / Doctor of Philosophy

Semi-insulating, powder samples of Cadmium Telluride (CdTe) have been studied using ������In Time Differential Perturbed Angular Correlation (PAC) Spectroscopy. The samples have been lightly doped (~10���� cm�����) with ������In atoms, which occupy well-defined metal (Cd) lattice sites and act as probes of the local environment. These substitutional donors form a single defect complex in CdTe. This complex has been identified and characterized as a function of temperature. Those indium probes that are not complexed occupy metal lattice sites with no defect in the local vicinity. Samples containing metal vacancy concentrations as large as 500 ppm have been prepared by a high temperature anneal and quench. The defect complex involves the trapping of a cadmium metal vacancy bound to the indium probe. The electric field gradient (EFG) experienced by probe atoms has a coupling constant of V[subscript Q]=61.5(5) MHz and is not axially symmetric, with the asymmetry parameter given by ��=0.16(4). It is believed that this asymmetry results from a relaxation of the chalcogen (Te) atoms adjacent to the metal vacancy, with the tellurium atom shared by the probe atom and the vacancy providing the dominant contribution. The fraction of complexed probe atoms increases as the sample temperature is decreased, and is still increasing at room temperature. Complexed fractions are reproducible on cycling within the temperature range 40 to 200��C. The binding energy of the complex has been measured to be 0.15(2) eV and is independent of metal vacancy concentration, which varies and is dependent on the details of the quench. In rapidly cooled samples, a non-equilibrium number of these defect complexes is observed. This state equilibrates with a time constant of 45(5) hours at 15��C, implying that at least one of the two constituents involved in the complex has a significant diffusion rate at this temperature. Under the assumption that vacancy diffusion mechanisms dominate at this temperature, it is found that the cadmium vacancies overcome an energy barrier of 0.9(1) eV with a jump time of 20(2) minutes in CdTe at 15��C. / Graduation date: 2002

No description available.

by Siu-Chung Wong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1988. / Bibliography: leaves 98-102.

published_or_final_version / abstract / toc / Physics / Master / Master of Philosophy

published_or_final_version / abstract / toc / Physics / Master / Master of Philosophy