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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A study of surface properties of III-nitride semiconductors by first principles total energy calculation

So, Wai-kei., 蘇偉基. January 2006 (has links)
published_or_final_version / abstract / Physics / Doctoral / Doctor of Philosophy
2

study of induced damages in surface cleaning and ion mixing in high resolution depth profiling under low energy argon ion sputtering. / 低能量氬離子濺射於表面淸潔及高解像深度剖析時所產生的損傷及離子混合的硏究 / A study of induced damages in surface cleaning and ion mixing in high resolution depth profiling under low energy argon ion sputtering. / Di neng liang ya li zi jian she yu biao mian qing jie ji gao jie xiang shen du pou xi shi suo chan sheng de sun shang ji li zi hun he de yan jiu

January 2000 (has links)
by Kwok-fung Kan = 低能量氬離子濺射於表面淸潔及高解像深度剖析時所產生的損傷及離子混合的硏究 / 簡國豐. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references. / Text in English; abstracts in English and Chinese. / by Kwok-fung Kan = Di neng liang ya li zi jian she yu biao mian qing jie ji gao jie xiang shen du pou xi shi suo chan sheng de sun shang ji li zi hun he de yan jiu / Jian Guofeng. / Abstract --- p.ii / 論文摘要 --- p.iii / Acknowledgement --- p.iv / Table of Contents --- p.v / List of Figures --- p.ix / List of Tables --- p.xi / Chapter Chapter 1 --- Background and Goals of the Thesis Work --- p.1 / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.1.1 --- Surface contamination of semiconductors --- p.1 / Chapter 1.1.2 --- Common surface cleaning methods --- p.2 / Chapter 1.1.3 --- Quality control in ultrathin gate dielectrics --- p.3 / Chapter 1.1.4 --- High-resolution depth profiling --- p.5 / Chapter 1.2 --- Energy range limitation in sputtering --- p.5 / Chapter 1.3 --- Goals of this thesis study --- p.6 / References for Chapter1 --- p.7 / Chapter Chapter 2 --- Theoretical Background and Instrumentation --- p.9 / Chapter 2.1 --- Ion Bombardment --- p.9 / Chapter 2.1.1 --- Bombardment mechanism --- p.9 / Chapter 2.1.2 --- Ion beam induced damage --- p.10 / Chapter 2.1.2.1 --- Region of damage --- p.10 / Chapter 2.1.2.2 --- Structural changes --- p.11 / Chapter 2.1.3 --- Assessment methods on ion beam damage and ion mixing --- p.12 / Chapter 2.1.3.1 --- Assessment methods on ion beam damage --- p.12 / Chapter 2.1.3.2 --- Assessment of ion mixing in the sample --- p.13 / Chapter 2.1.4 --- Minimizing the sputtered damage and ion mixing --- p.14 / Chapter 2.1.5 --- Ion gun --- p.15 / Chapter 2.1.5.1 --- Mechanism of the generation of an argon ion beam --- p.15 / Chapter 2.1.5.2 --- Description of ion gun --- p.16 / Chapter 2.1.5.3 --- Calibration of current density provided by the ion gun --- p.16 / Chapter 2.1.5.4 --- Sputtering time --- p.16 / Chapter 2.2 --- X-ray photoelectron spectroscopy(XPS) --- p.18 / Chapter 2.2.1 --- Principle of XPS --- p.18 / Chapter 2.2.1.1 --- Qualitative analysis of XPS --- p.18 / Chapter 2.2.1.2 --- Quantitative analysis of XPS --- p.20 / Chapter 2.2.2 --- Angle-resolved XPS --- p.24 / Chapter 2.2.3 --- Set-up --- p.25 / Chapter 2.2.3.1 --- UHV system --- p.27 / Chapter 2.2.3.2 --- X-ray source --- p.27 / Chapter 2.2.3.3 --- Electron energy analyser --- p.27 / Chapter 2.2.3.4 --- Detector --- p.28 / Chapter 2.2.4 --- Calibration of XPS --- p.28 / References for Chapter2 --- p.29 / Chapter Chapter 3 --- Damages induced by ion sputtering --- p.31 / Chapter 3.1 --- Introduction --- p.31 / Chapter 3.2 --- Experimental --- p.31 / Chapter 3.2.1 --- Sample preparation --- p.31 / Chapter a. --- Surface cleaning and oxidization --- p.31 / Chapter b. --- HF etching --- p.32 / Chapter c. --- Indium back contact --- p.32 / Chapter 3.2.2 --- XPS analysis --- p.33 / Chapter 3.2.2.1 --- Data acquisition --- p.33 / Chapter 3.2.2.2 --- Peak deconvolution --- p.33 / Chapter 3.2.3 --- Ion sputtering --- p.34 / Chapter 3.3 --- Results and discussion --- p.34 / Chapter 3.3.1 --- Spectral width of In3d and P2p peak --- p.34 / Chapter 3.3.2 --- Deconvolution of In3d signal at take-off angle of 90° --- p.37 / Chapter 3.3.2.1 --- In in bulk InP --- p.37 / Chapter 3.3.2.2 --- In metal --- p.37 / Chapter 3.3.2.3 --- In in damaged InP region --- p.37 / Chapter 3.3.3 --- Deconvolution of P2p signal at take off angle of 45° --- p.37 / Chapter 3.3.3.1 --- P in bulk InP --- p.37 / Chapter 3.3.3.2 --- P in damaged InP region --- p.37 / Chapter 3.3.4 --- Relative composition of deconvoluted components --- p.38 / Chapter 3.3.5 --- Fermi level shift --- p.39 / Chapter 3.3.6 --- Analysis at take-off angle of 45° --- p.40 / Chapter 3.3.7 --- Stoichiometry in sputtered InP --- p.43 / Chapter 3.4 --- Conclusions --- p.45 / References for Chapter3 --- p.46 / Chapter Chapter 4 --- Ion mixing in sputtered depth profiling --- p.47 / Chapter 4.1 --- Introduction --- p.47 / Chapter 4.2 --- Experimental --- p.47 / Chapter 4.2.1 --- Sample description --- p.47 / Chapter 4.2.2 --- Acquisition conditions --- p.47 / Chapter 4.2.3 --- Raw data --- p.48 / Chapter 4.2.4 --- Data treatments --- p.48 / Chapter 4.2.4.1 --- Depth calibration --- p.48 / Chapter 4.2.4.2 --- Calibration procedure --- p.55 / Chapter A. --- Overlayer region --- p.55 / Chapter B. --- Substrate region --- p.56 / Chapter 4.3 --- Results and discussions --- p.57 / Chapter 4.3.1 --- Study of ion mixing using depth profile --- p.57 / Chapter A. --- Comparing the carbon profiles at two ion sputtering energies --- p.59 / Chapter B. --- Comparing the nitrogen profiles at two ion sputtering energies --- p.59 / Chapter C. --- Comparing the oxygen profiles at two ion sputtering energies --- p.59 / Chapter 4.3.2 --- Study of ion mixing from a change in sputtering rate --- p.60 / Chapter 4.3.3 --- Approximation on ion mixing --- p.64 / Chapter 4.3.4 --- Conclusions --- p.66 / References for Chapter4 --- p.67 / Chapter Chapter 5 --- Conclusions --- p.68
3

Chemical-mechanical planarization of lithium gallate

Taylor, Andre D. 12 1900 (has links)
No description available.
4

Chemical reactions at the interfaces of semiconductors and catalysts with solutions: I. Tin-palladium catalysts in electroless copper plating. II. Dissolution of crystalline gallium-arsenide in solutions containing complexing agents.

Pierson, Bruce Gregory. January 1989 (has links)
The concentration of tin and palladium in catalysts used in electroless copper plating have been determined by Rutherford backscattering spectrometry with high energy (2-5) MeV ⁴He⁺. The tin:palladium ratio in the catalyst decreases when exposed to an alkaline solution. X-ray photoelectron spectroscopy has confirmed this result and has shown the palladium in the catalyst is present as palladium metal and the tin is present, probably as an oxidized species, to a depth of about 30 Å. Catalysts for the electroless plating of copper are obtained by the reaction of Pd(II) and Sn(II). The extent of the reaction and the concentrations of the reaction products depend on the solution conditions. Conflicting results obtained in previous investigations of tin-palladium catalysts can be explained on this basis. Single crystals of gallium arsenide (GaAs(100)) were found to dissolve in synthetic lung fluid (Gamble solution). The concentrations of arsenic and gallium in the Gamble solution as well as the arsenic:gallium ratio on the GaAs surface increased continuously as the time of exposure to the Gamble solution increased. X-ray photoelectron spectroscopic studies of the gallium arsenide surface showed that arsenic migrated to the surface and it was oxidized to a species resembling As₂O₃ and finally solubilized by the Gamble solution. The solubility of gallium was governed primarily by the formation of stable complexes with the citrate and phosphate ions in the Gamble solution. Zinc that was present in the single crystals of gallium arsenide also migrated to the surface.
5

Physical damage and damage removal on indium phosphide and gallium arsenide surfaces using low energy ions. / Physical damage and damage removal on InP and GaAs surfaces using low energy ions / CUHK electronic theses & dissertations collection

January 2001 (has links)
Thesis (Ph.D.)--Chinese University of Hong Kong ,2001. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.
6

Surface charge spectroscopy: 表面電荷解譜儀. / 表面電荷解譜儀 / CUHK electronic theses & dissertations collection / Surface charge spectroscopy: Biao mian dian he jie pu yi. / Biao mian dian he jie pu yi

January 1999 (has links)
by Raymon, Wai-man Chan. / "March 1999." / Thesis (Ph.D.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese. / by Raymon, Wai-man Chan.
7

Visualization of colloidal particle dynamics at a solid-liquid interface

Zettner, Claudia Margaret 12 1900 (has links)
No description available.
8

Reordering at the gas-phase polysulfide-passivated InP and GaAs surfaces.

January 1996 (has links)
by So King Lung, Benny. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaves 102-109). / ABSTRACT --- p.v / ACKNOWLEDGEMENTS --- p.vii / LIST OF FIGURES --- p.viii / LIST OF TABLES --- p.xiii / Chapter Chapter 1 --- Background of the study --- p.1 / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.2 --- Surface passivation techniques --- p.3 / Chapter 1.2.1 --- Sulfide solution passivation --- p.3 / Chapter 1.2.2 --- Gas-phase sulfide passivation --- p.4 / Chapter 1.3 --- Surface structure of sulfide-passivated surface --- p.5 / Chapter 1.4 --- Objectives of the present study --- p.7 / Chapter Chapter 2 --- Instrumentation --- p.9 / Chapter 2.1 --- Introduction --- p.9 / Chapter 2.2 --- X-ray photoelectron spectroscopy (XPS) --- p.9 / Chapter 2.2.1 --- The development of XPS --- p.9 / Chapter 2.2.2 --- Basic principle of XPS --- p.9 / Chapter 2.2.3 --- Quantitative analysis of XPS --- p.14 / Chapter 2.2.3.1 --- Atomic concentration of a homogenous material --- p.14 / Chapter 2.2.3.2 --- Layer structure --- p.15 / Chapter 2.2.3.3 --- Simulation of XPS atomic concentration ratios from proposed surface structural models --- p.17 / Chapter 2.2.4 --- XPS experiment --- p.19 / Chapter 2.3 --- Low energy electron diffraction (LEED) --- p.21 / Chapter 2.3.1 --- The development of LEED --- p.21 / Chapter 2.3.2 --- Basic principle of LEED --- p.23 / Chapter 2.3.3 --- LEED experiment --- p.28 / Chapter 2.3.3.1 --- The ultra high vacuum chamber (UHV) --- p.28 / Chapter 2.3.3.2 --- The electron gun --- p.28 / Chapter 2.3.3.3 --- The sample --- p.30 / Chapter 2.3.3.4 --- The detector system --- p.30 / Chapter Chapter 3 --- Surface treatments --- p.31 / Chapter 3.1 --- Semiconductor wafers --- p.31 / Chapter 3.2 --- Cleaning procedure --- p.31 / Chapter 3.3 --- Polysulfide passivation --- p.33 / Chapter Chapter 4 --- Gas-phase polysulfide passivation of the InP(100) surface --- p.37 / Chapter 4.1 --- Introduction --- p.37 / Chapter 4.2 --- Sulfide-assisted reordering at the InP(100) surface --- p.38 / Chapter 4.2.1 --- Gas-phase polysulfide-treated InP( 100) surface --- p.38 / Chapter 4.2.2 --- Further annealing of the gas-phase polysulfide-treated surface --- p.47 / Chapter 4.2.3 --- Comparison with the UV/O3-HF treatment --- p.48 / Chapter 4.2.4 --- Sulfide at the interface of SiNx/InP --- p.49 / Chapter 4.3 --- Conclusions --- p.53 / Chapter Chapter 5 --- Gas-phase polysulfide passivation of the GaAs(lOO) surface --- p.55 / Chapter 5.1 --- Introduction --- p.55 / Chapter 5.2 --- Gas-phase poly sulfide-passivated GaAs( 100) surface --- p.56 / Chapter 5.2.1 --- Surface structure of the as-treated surface --- p.56 / Chapter 5.2.2 --- Surface structure after further annealing --- p.64 / Chapter 5.2.3 --- Mechanism of the gas-phase polysulfide passivation --- p.67 / Chapter 5.3 --- Conclusions --- p.68 / Chapter Chapter 6 --- Gas-phase polysulfide passivation of the GaAs(100) surface --- p.69 / Chapter 6.1 --- Introduction --- p.69 / Chapter 6.2 --- Reordering at the gas-phase polysulfide-passivated GaAs(100) surface --- p.70 / Chapter 6.2.1 --- Adsorption of polysulfide on the GaAs(100) surface --- p.70 / Chapter 6.2.2 --- Ordered sulfide at the GaAs(l 10) surface --- p.73 / Chapter 6.2.3 --- Further analysis of the LEED pattern --- p.80 / Chapter 6.3 --- Conclusions --- p.83 / Chapter Chapter 7 --- Sulfide Solution passivation of the GaAs(100) surface --- p.84 / Chapter 7.1 --- Introduction --- p.84 / Chapter 7.2 --- Sulfide solution passivation on the GaAs(l 10) surface --- p.85 / Chapter 7.2.1 --- Etching of sulfide solution on the GaAs(l 10) surface --- p.85 / Chapter 7.2.2 --- Annealing of sulfide solution-passivated GaAs( 110) surface --- p.88 / Chapter 7.2.3 --- Further analysis of the LEED pattern --- p.92 / Chapter 7.2.4 --- Shift of XPS peak position during annealing --- p.95 / Chapter 7.3 --- Conclusions --- p.97 / Chapter Chapter 8 --- Conclusions and further work --- p.99 / Chapter 8.1 --- Conclusions --- p.99 / Chapter 8.2 --- Further work --- p.100 / References --- p.102
9

Sulfide and UV/ozone treatments on III-V semiconductors =: 用硫及紫外光/臭氧處理III-V 族半導體. / 用硫及紫外光/臭氧處理III-V 族半導體 / Sulfide and UV/ozone treatments on III-V semiconductors =: Yong liu ji zi wai guang/xiu yang chu li III-V zu ban dao ti. / Yong liu ji zi wai guang/xiu yang chu li III-V zu ban dao ti

January 1998 (has links)
by Choy Wing Hong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 95-102). / Text in English; abstract also in Chinese. / by Choy Wing Hong. / ABSTRACT --- p.vi / ACKNOWLEDGEMENTS --- p.x / LIST OF FIGURES --- p.xi / LIST OF TABLES --- p.xiii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- Surface passivation techniques --- p.2 / Chapter 1.2.1 --- Sulfide solution passivation --- p.2 / Chapter 1.2.2 --- Gas-phase sulfide passivation --- p.3 / Chapter 1.2.3 --- Ultra-violet and ozone exposure --- p.4 / Chapter 1.3 --- Surface structure of sulfide-passivated surface --- p.5 / Chapter 1.4 --- Surface structure of ultra-violet/ozone oxidation --- p.8 / Chapter 1.5 --- Objectives of present study --- p.10 / Chapter Chapter 2 --- Instrumentation --- p.12 / Chapter 2.1 --- Introduction --- p.12 / Chapter 2.2 --- Atomic force microscopy (AFM) --- p.12 / Chapter 2.2.1 --- The development of AFM --- p.12 / Chapter 2.2.2 --- Basic principles of AFM --- p.12 / Chapter 2.2.3 --- Forces and their relevance to atomic force microscopy --- p.13 / Chapter 2.2.3.1 --- Van Der Waals forces --- p.15 / Chapter 2.2.3.2 --- Repulsive forces --- p.15 / Chapter 2.2.3.3 --- Capillary forces --- p.15 / Chapter 2.2.4 --- Displacement sensor of AFM --- p.15 / Chapter 2.2.4.1 --- Electron tunneling --- p.16 / Chapter 2.2.4.2 --- Optical interference --- p.16 / Chapter 2.2.4.3 --- Laser beam deflection --- p.16 / Chapter 2.2.5 --- Instrument specification --- p.17 / Chapter 2.2.5.1 --- Contact mode AFM --- p.17 / Chapter 2.3 --- X-ray photoelectron spectroscopy --- p.19 / Chapter 2.3.1 --- The development of XPS --- p.19 / Chapter 2.3.2 --- Basic principles of XPS --- p.19 / Chapter 2.3.3 --- XPS experiments --- p.23 / Chapter 2.3.4 --- Quantitative analysis --- p.26 / Chapter 2.3.4.1 --- Atomic concentration of a homogenous materials --- p.26 / Chapter 2.3.4.2 --- Layer structure --- p.27 / Chapter 2.4 --- Rutherford backscattering spectrometry (RBS) --- p.29 / Chapter 2.4.1 --- Basic principles --- p.29 / Chapter 2.4.2 --- Kinematics --- p.29 / Chapter 2.4.3 --- Channeling --- p.31 / Chapter Chapter 3 --- Surface treatments --- p.32 / Chapter 3.1 --- Semiconductor wafer --- p.32 / Chapter 3.2 --- Cleaning procedures --- p.32 / Chapter 3.3 --- Polysulfide passivation --- p.34 / Chapter 3.4 --- UV/Ozone oxidation --- p.39 / Chapter Chapter 4 --- Surface roughness and oxide contents of sulfide passivation --- p.41 / Chapter 4.1 --- Introduction --- p.41 / Chapter 4.2 --- Experimental methodology --- p.42 / Chapter 4.3 --- Etching --- p.44 / Chapter 4.3.1 --- Etching effect of polysulfide solution --- p.45 / Chapter 4.3.2 --- Possible consequences of the etching effect --- p.45 / Chapter 4.4 --- Oxide contents --- p.47 / Chapter 4.4.1 --- Oxide gained during polysulfide solution treatment --- p.47 / Chapter 4.4.2 --- Oxide gained after polysulfide passivation --- p.47 / Chapter 4.5 --- Surface roughness --- p.49 / Chapter 4.5.1 --- Surface roughness after different passivation methods --- p.49 / Chapter 4.5.2 --- The sticking probability after different passivations --- p.51 / Chapter 4.6 --- The spiral ladder of solution-phase passivation --- p.55 / Chapter 4.7 --- Conclusions --- p.58 / Chapter Chapter 5 --- Sulfide on Ge/GaAs heterojunction --- p.59 / Chapter 5.1 --- Introduction --- p.59 / Chapter 5.1.1 --- Band structure of Ge/GaAs heteroj unction --- p.59 / Chapter 5.1.2 --- Lattice match of Ge/GaAs heteroj unction --- p.60 / Chapter 5.1.3 --- The growth of Ge on GaAs using molecular beam epitaxy --- p.62 / Chapter 5.2 --- The growth of Ge on GaAs using thermal pulse annealing --- p.63 / Chapter 5.3 --- Sulfide as an atomic interdiffusion barrier --- p.65 / Chapter 5.3.1 --- Experimental methodology --- p.65 / Chapter 5.3.2 --- Crystallinity of Ge --- p.67 / Chapter 5.3.3 --- Results and discussions --- p.67 / Chapter 5.3.3.1 --- RBS and XPS results --- p.67 / Chapter 5.3.3.2 --- AFM and I-V results --- p.71 / Chapter 5.4 --- Conclusions --- p.71 / Chapter Chapter 6 --- UV/03 on Ge/GaAs heterojunction --- p.72 / Chapter 6.1 --- Introduction of UV/o3 oxidation --- p.72 / Chapter 6.2 --- UV/o3 oxidation on GaAs --- p.74 / Chapter 6.3 --- Ge on UV/o3 treated GaAs --- p.76 / Chapter 6.3.1 --- Experimental methodology --- p.76 / Chapter 6.3.2 --- Crystallinity of Ge --- p.77 / Chapter 6.3.3 --- AFM results --- p.77 / Chapter 6.3.4 --- RBS results --- p.80 / Chapter 6.4 --- Diodes --- p.82 / Chapter 6.4.1 --- Fabrication of diode --- p.82 / Chapter 6.4.2 --- Diode characteristics --- p.84 / Chapter 6.4.3 --- I-V characteristics --- p.90 / Chapter 6.5 --- Conclusions --- p.90 / Chapter Chapter 7 --- Conclusion and future work --- p.93 / Chapter 7.1 --- Conclusions --- p.93 / Chapter 7.2 --- Future works --- p.94 / Reference --- p.95
10

Two-dimensional CCD position sensor system for active magnetic bearings

Sithole, Phila Elvis January 2007 (has links)
M. Tech. Digital Technology. / This dissertation reports on an optical-based two-dimensional position sensor for use in Active Magnetic Bearings (AMB) to measure the position of the levitated rotor. The motivation for the deployment of optical technology is the well-known advantage of high precision contactless displacement measurement. The radial and axial edges of the rotor are illuminated by red and green laser beams respectively. The position of the rotor is determined from its image projected on a Charge Coupled Device (CCD) sensor. The measuring principle is demonstrated as a position sampler in the closed loop control of an active magnetic bearing model. The image representing the position is processed with a real-time algorithm on a Field Programmable Logic Gate Array. The principle of operation of a CCD as a position sensor is analysed in order to establish how the image captured by the CCD can be processed to determine the position of the rotor. A simple AMB is modelled in which the sensor acts as a feedback position device. The main objective of the model is to evaluate the accuracy of the system. The purpose of the overall sensing technique to be used is to achieve highly accurate and precise measurements with CCD-based optical metrology.

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