Dissertations / Theses on the topic 'Vacuum optical thin-film coating'

Дисертація на здобуття наукового ступеня кандидата технічних наук (Ph.D) за спеціальністю 05.17.11 – технологія тугоплавких неметалічних матеріалів. – Національний технічний університет "Харківський політехнічний інститут", Харків, 2019. Дисертація присвячена створенню оптичних кольорових стекол зі спектральними параметрами – коефіцієнтом пропускання на довжині хвилі 1060 τ(λ₁₀₆₀) >65 %, поглинанням у спектральному діапазоні до 950 нм та технологіям їх отримання. На цей час існуючі стекла лише частково виконують ці умови, або технології їх отримання є нерентабельними для масового виробництва, тому було поставлена задача про створення стекол, які б могли задовольняти ці умови з фактором технологічності у виробництві. Вирішення досягнуто завдяки дослідженням поглинальної дії системи барвників Cr₂O₃-Mn₂O₃ у системі R₂O-PbO-SiO₂ та додатковому нанесенню оптичного покриття. Завдяки дослідженням було встановлено механізми забарвлення з урахуванням впливу домішок-барвників (Fe₂O₃/FeO), а також знайдені оптимальні концентрації барвників у склі. При розробці технології отримання оптичного кольорового скла були дослідженні основні технічні операції та методи контролю якості скла, що дозволяє отримувати дане скло у виробничому масштабі. Розроблені параметри контролю протікання процесів гомогенізації та освітлення розплаву скла з метою підвищення якості продукції. Також були розроблені методики обробки деталей зі скла та нанесення оптичних покриттів. Для автоматизації виробництва даної продукції та зменшення впливу людського фактору було розроблено програмне забезпечення автоматичної системи керування технологічними процесами (АСК ТП).
Dissertation for the Ph.D. degree in specialty 05.17.11 – "Technology of refractory nonmetallic materials". – National Technical University "Kharkiv Polytechnic Institute", Kharkiv, 2019. The dissertation is devoted to the development of infrared optical glasses with next spectral characteristics, as well as the creation of technologies for their production. The spectral characteristics are transmittance at a wavelength of 1060 nm 1060 τ (λ₁₀₆₀)>65% and absorption in the spectral range up to 950 nm. The solution to this problem was achieved due to the addition of the Cr₂O₃-Mn₂O₃ colorant system to the glass matrix of the R₂O-PbO-SiO₂ system, as well as the additional optical thin-film coatings. For production implementation optical color glass a pot regenerator furnace was used. The ceramic vessel with a volume of 500 liters was chosen. The temperature of the production was 1420 ± 20 °С. To improve the quality of optical glass practical studies were carried out. These studies devote to the modes of batch filling, mixing and temperature parameters. Fundamental researches were conducted on the mode of cooling of colored optical glass. For the first time for such glasses the stage of cooling made by inertia cooling of the furnace construction without gas. Due to introduction of the results and improving of the spectral parameters the volume of quality glass yield has increased. The software was developed to control the technological processes of the furnace in automatic mode.

Дисертація на здобуття наукового ступеня кандидата технічних наук (Ph.D) за спеціальністю 05.17.11 – технологія тугоплавких неметалічних матеріалів. – Національний технічний університет "Харківський політехнічний інститут", Харків, 2019. Дисертація присвячена створенню оптичних кольорових стекол зі спектральними параметрами – коефіцієнтом пропускання на довжині хвилі 1060 τ(λ₁₀₆₀) >65 %, поглинанням у спектральному діапазоні до 950 нм та технологіям їх отримання. На цей час існуючі стекла лише частково виконують ці умови, або технології їх отримання є нерентабельними для масового виробництва, тому було поставлена задача про створення стекол, які б могли задовольняти ці умови з фактором технологічності у виробництві. Вирішення досягнуто завдяки дослідженням поглинальної дії системи барвників Cr₂O₃-Mn₂O₃ у системі R₂O-PbO-SiO₂ та додатковому нанесенню оптичного покриття. Завдяки дослідженням було встановлено механізми забарвлення з урахуванням впливу домішок-барвників (Fe₂O₃/FeO), а також знайдені оптимальні концентрації барвників у склі. При розробці технології отримання оптичного кольорового скла були дослідженні основні технічні операції та методи контролю якості скла, що дозволяє отримувати дане скло у виробничому масштабі. Розроблені параметри контролю протікання процесів гомогенізації та освітлення розплаву скла з метою підвищення якості продукції. Також були розроблені методики обробки деталей зі скла та нанесення оптичних покриттів. Для автоматизації виробництва даної продукції та зменшення впливу людського фактору було розроблено програмне забезпечення автоматичної системи керування технологічними процесами (АСК ТП).
Dissertation for the Ph.D. degree in specialty 05.17.11 – "Technology of refractory nonmetallic materials". – National Technical University "Kharkiv Polytechnic Institute", Kharkiv, 2019. The dissertation is devoted to the development of infrared optical glasses with next spectral characteristics, as well as the creation of technologies for their production. The spectral characteristics are transmittance at a wavelength of 1060 nm 1060 τ (λ₁₀₆₀)>65% and absorption in the spectral range up to 950 nm. The solution to this problem was achieved due to the addition of the Cr₂O₃-Mn₂O₃ colorant system to the glass matrix of the R₂O-PbO-SiO₂ system, as well as the additional optical thin-film coatings. For production implementation optical color glass a pot regenerator furnace was used. The ceramic vessel with a volume of 500 liters was chosen. The temperature of the production was 1420 ± 20 °С. To improve the quality of optical glass practical studies were carried out. These studies devote to the modes of batch filling, mixing and temperature parameters. Fundamental researches were conducted on the mode of cooling of colored optical glass. For the first time for such glasses the stage of cooling made by inertia cooling of the furnace construction without gas. Due to introduction of the results and improving of the spectral parameters the volume of quality glass yield has increased. The software was developed to control the technological processes of the furnace in automatic mode.

Evaluation of the wet etching properties of several different thin film oxidesgrown by physical vapour deposition was performed in this work. MgO, Al2O3,SiO2, TiO2, HfO2 ZrO2 and Y2O3 were coated on two types of substrates; Si andborosilicate glass and etching tests were performed in different etchingsolutions. MgF2 thin films have also been evaluated. Important aspects of the choice of the thin films was taken into account in orderto match to good optical properties such as refractive index (n), extinction coefficient (k) and optical thickness (TP) as well as good chemical properties in the wet etching process. A description is made of the physics of optical filters and how a combination of different oxides stacked onto each other can create interference filters. A description of the manufacturing process of the thin films where physical vapour deposition (PVD) was used is presented. Thermal shift of the optical spectra caused by porous coatings was investigated and analyses of the thin films by ellipsometry, surface profilometry and transmission spectrophotometry have been performed. The wet etching properties were evaluated by monitoring the transmission insituon transparent borosilicate glass substrates. A method of how to measure the wet etching rate for different thin films is described. A computer software was used to calculate the Pourbaix diagrams in order to understand the chemical behaviour of the etching solutions. The pH can have a significant impact on the etching behaviour. In case of TiO2, it can be dissolved in an alkaline solution of H2O2. The catalytically process behind this is evaluated. Etching rate for both Y2O3 andSiO2 were matched by adjusting the etchant concentration as a case example. The group IVB oxides are difficult to etch. The catalytic etching of TiO2 with peroxide is slow but detectable. Al2O3, Y2O3 and MgO are reasonably easy to etch but have too low refractive indices to be useful in multilayer optical filters. The In-situ etching instrument was found to be very useful for measuring etching rates.
Utvärdering av våtkemiska egenskaper för flera olika oxidtunnfilmer utfördes idetta arbete på tunnfilmer av MgO, Al2O3, SiO2, TiO2, HfO2 ZrO2 and Y2O3 vakuumdeponerade på både kiselwafers och borosilikatglas. Etstester gjordes med ett flertal etslösningar. Även MgF2-tunnfilmer utvärderades. Både optiska och kemiska egenskaper togs i beaktande vid utvärderingen av tunnfilmerna. De optiska lagar som gäller för tunnfilmer redovisas, bl a hur kombinationer av olika oxider kan skapa interferrensfilter. En beskrivning av tillverkningsprocessen varvid PVD användes presenteras. Termiskt skift av det optiska transmissionsspektrat orsakat av porositet undersöktes. Analyser av tunnfilmerna med ellipsometri, profilometri och transmissions spektroskopi utfördes. Våtetsningsegenskaperna utvärderades genom att mäta in-situ vid etsprocessen på transparenta borosilikatglassubstrat. Metoden för att mäta etshastigheten för olika oxider är beskriven. Datorberäkningar av pourbaixdiagram användes för att skapa en förståelse av de kemiska egenskaperna för etslösningarna. Etsegenskaperna påverkas till stordel av lösningens pH. TiO2 kan etsas i basisk lösning av peroxid. Denna process utvärderades, likaså utvärderades etshasigheten för Y2O3 och SiO2 för att erhålla matchande par avoxider som en fallstudie. Grupp IVB oxiderna är mycket svåra att etsa. Katalytisk etsning av TiO2 med peroxid är detekterbar men långsam. Al2O3, Y2O3 och MgO är förhållandevis enkla att etsa men har för låga brytningsindex för att var praktiskt använbara i optiska multilagerfilter. In-situ etsinstrumentet befanns vara ett utmärkt verktyg för att mäta etshastigheten för tunnfilmer.

This thesis treats the development of packaging and integration methods for the cost-efficient encapsulation and packaging of microelectromechanical (MEMS) devices. The packaging of MEMS devices is often more costly than the device itself, partly because the packaging can be crucial for the performance of the device. For devices which contain liquids or needs to be enclosed in a vacuum, the packaging can account for up to 80% of the total cost of the device. The first part of this thesis presents the integration scheme for an optical dye thin film NO2-gas sensor, designed using cost-efficient implementations of wafer-scale methods. This work includes design and fabrication of photonic subcomponents in addition to the main effort of integration and packaging of the dye-film. A specific proof of concept target was for NO2 monitoring in a car tunnel. The second part of this thesis deals with the wafer-scale packaging methods developed for the sensing device. The developed packaging method, based on low-temperature plastic deformation of gold sealing structures, is further demonstrated as a generic method for other hermetic liquid and vacuum packaging applications. In the developed packaging methods, the mechanically squeezed gold sealing material is both electroplated microstruc- tures and wire bonded stud bumps. The electroplated rings act like a more hermetic version of rubber sealing rings while compressed in conjunction with a cavity forming wafer bonding process. The stud bump sealing processes is on the other hand applied on completed cavities with narrow access ports, to seal either a vacuum or liquid inside the cavities at room temperature. Additionally, the resulting hermeticity of primarily the vacuum sealing methods is thoroughly investigated. Two of the sealing methods presented require permanent mechanical fixation in order to complete the packaging process. Two solutions to this problem are presented in this thesis. First, a more traditional wafer bonding method using tin-soldering is demonstrated. Second, a novel full-wafer epoxy underfill-process using a microfluidic distribution network is demonstrated using a room temperature process.

QC 20130325

Thin polymer films and their properties have been investigated. The characteristics of crystalline polymers according to film thickness have been improved using polycaprolactone (PCL). The melting enthalpy of PCL has increased when the film thickness decreased and the peak melting temperature showed no significant changes with film thickness. Film thickness variation influenced surface roughness and crystal size. Optical microscope images showed the rougher surface of thicker films. The spinning time has shown no influence on film thickness and no significant changes to surface roughness. Thin films of block copolymers were used in the surface modification study; films studied included poly(styrene-b-butadiene-b-styrene) (SBS) and poly(styrene-b-isoprene-b-styrene) (SIS) and their surface modifications have been controlled using different methods of treatment. Films of SIS heated at different temperatures have shown different surface texture and roughness. Films treated at low temperature (45 °C) had smooth surfaces when compared with films heated at high temperature (120 °C and 160 °C). Phase separation of SIS heated at (120 °C and 160 °C) caused bulges of different sizes to cover the surface. The height and width of the bulges showed variation with film thickness and heating. Substrate interaction with SBS and SIS block copolymer films showed different surface texture when using the same type of substrate and different texture were obtained when SBS solutions were spun onto different substrates. It has been demonstrated that using different solvents in copolymer preparation caused different texture. Thermal and surface property variations with film thickness have been improved using amorphous polymers. Surface roughness of poly(methyl methacrylate) PMMA and disperse red 1-poly(methyl methacrylate) DR1-PMMA, PMMA has improved using thickness variation. Glass transition temperature measurement has increased when film thickness was increased. The glass transition temperature (Tg) and surface roughness of UV15 UV - curable coating polymer has been modified using UV curing and heating methods. Tg variation was observed when curing time and curing intensity were changed causing the optical properties of the polymer to be more variable. A plasma etcher caused wrinkles to occur on the surface of unheated UV15. Tg of UV15 increased when curing time increased. The Fourier Transform Infrared Spectroscopy (FTIR) spectra of cured UV15 film have shown peak variations of the ester and carbon double bond regions over the range of 1850-1700 cm-1. Urethane-Urea (UU) Polymer thin films were used to investigate optical properties and develop an optical waveguide. Absorption and transmission properties of light using non-linear optical (NLO) polymer was investigated and used in optical waveguide fabrication. Refractive indices were measured to examine UU films at two different wavelengths. A UU film of 1 µm thickness caused a maximum absorption at max = 471 nm also obtained at 810 nm wavelength. Many methods of fabrication were used; photolithography, plasma etching in a barrel reactor and thin film deposition using sputtering and evaporation. Etched depths from 1 μm to 100 μm were obtained. An optical waveguide has been prepared using plasma etching of a cured UV15 as a cladding layer on a silicon substrate.

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2014.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 124-129).
For the class of nondispersive, nonabsorbing, multilayer thin-film optical systems, this thesis work develops a parallel branch-and-bound computational system on Amazon's EC2 platform, using the Taylor model mathematical/computational system due to Berz and Makino to construct tight rigorous bounds on the merit function on subsets of the search space (as required by a branch-and-bound algorithm). This represents the first, to the best of our knowledge, deterministic global optimization algorithm for this important class of problems, i.e., the first algorithm that can guarantee that a global solution to an optimization problem in this class has been found. For the particular problem of reducing reflection using multilayer systems, it is shown that a gradient index constraint on the solution can be exploited to significantly reduce the search space and thereby make the algorithm more practical. This optimization system is then used to design a broadband omnidirectional antireflection coating for silicon solar energy. The design is experimentally validated using RF sputtering, and shows performance that is competitive with existing solutions based on impractical sophisticated nano-deposition techniques, as well as the more practical but also more narrowly applicable solutions based on texturing. This makes it arguably the best practical solution to this important problem to date. In addition, this thesis develops a mathematical theory for cheaply (in the computational sense) and tightly bounding solutions to parametric weakly-coupled semilinear parabolic (reaction-diffusion) partial differential equation systems, as motivated by the design of tandem organic solar cell structures (which are governed by the drift-diffusion-Poisson system of equations). This represents the first theoretical foundation, to the best of our knowledge, to enable guaranteed global optimization of this important class of problems, which includes, but is broader, than many semiconductor design problems. A serial branch-and-bound algorithm implementation illustrates the applicability of the bounds on a pair of simple examples.
by Paul Azunre.
Ph. D.

The major part of my dissertation consists of thin films deposited using atomic layer deposition on flat and powder substrates. It details the various optimization experiments for process parameters like dose time, purge time, temperature, and pressure on silicon shards and powder substrates. Spectroscopic ellipsometry (SE) was used to characterize these films over a wide wavelength range (191-1688 nm). An optical model with a BEMA (Bruggeman effective medium approximation) layer was used to fit the ellipsometric data to investigate the optical properties of the alumina surface. The optimized process parameters on the flat surfaces were used for coating powder substrates. I propose a set of experiments to optimize the conditions for coating of powders and high aspect ratio structures by atomic layer deposition (ALD). The coated powders were analyzed by surface analytical techniques like X-ray photoelectron spectroscopy, spectroscopic ellipsometry, transmission electron microscopy, energy X-ray dispersive spectroscopy (EDAX), and BET. The first chapter introduces the technique of atomic layer deposition, and details its advantages and limitations over conventional thin film deposition techniques like chemical vapor deposition and physical vapor deposition. The second chapter details the initial deposition experiments performed on flat surfaces and characterization of thin films using surface analytical tools. I conducted multi-sample analysis on eleven different thin films for calculation of optical constants of alumina. The third chapter introduces thin film deposition experiments performed on powder substrates, several challenges associated with achieving conformal thin films and characterization. The fourth chapter details the experiments to achieve unilateral ALD achieved on one side of the substrates. The fifth chapter details various unconventional materials including liquid water, Coca-Cola, a coffee bean, nitrogen gas, human tooth, and printed office paper, which were analyzed by near ambient pressure XPS (NAP-XPS). This dissertation contains appendices of other tutorial articles I wrote on obtaining optical constants liquid samples using spectroscopic ellipsometry, and good experimental techniques for maintenance of vacuum equipment.

Ultrathin film nanocomposites are becoming increasingly important for specialized performance of commercial coatings. Critical challenges for ultrathin film nanocomposites include their synthesis and characterization as well as their performance properties, including surface roughness, optical properties (haze, refractive index as examples), and mechanical properties. The objective of this work is to control the surface roughness of ultrathin film nanocomposites by changing the average particle size and the particle volume fraction (loading) of monomodal particle size distributions. This work evaluated one-layer and two-layer films for their surface properties. Monodispersed colloidal silica nanoparticles were incorporated into an acrylate-based monomer system as the model system. Ultrathin nanocomposites were prepared with three different size colloidal silica (13, 45, and 120 nm nominal diameters) at three different particle loadings (20, 40, and 50 vol. % inorganic solids). Silica particles were characterized using DLS and TEM. AFM was used to measure the root mean square roughness (Rq), ΔZ, and location-to-location uniformity of one-layer and two-layer nanocomposite coatings. Developing an understanding about the properties affected by the type and amount of particles used in a nanocomposite can be used as a tool with nanocharacterization techniques to quickly modify and synthesize desired ultrathin film coatings.

Interference filters are multilayer thin film devices. They use interference effects between the incident and reflected radiation waves at each layer interface to select wavelengths. The production of interference filters depend on the precise deposition of thin material layers on substrates which have suitable optical properties. In this thesis, the main target is to design and produce two optical filters (short-pass filter and long-pass filter) for the CCDs that will be used in the electronics of a space camera. By means of these filters, it is possible to take image in different bands (RGB and NIR) by identical two CCDs. The filters will be fabricated by plasma ion-assisted deposition technique.

Die vorliegende Dissertation behandelt Charakterisierung, Modellbildung sowie Anwendung einer magnetfeldgestützten Hohlkathoden-Bogenentladung. Hohlkathoden sind seit den 1960er Jahren Gegenstand grundlagen- sowie anwendungsorientierter Forschung und werden seit 20 Jahren am Fraunhofer-Institut für Elektronenstrahl- und Plasmatechnik für die Anwendung auf dem Gebiet der Vakuumbeschichtung weiterentwickelt. Ziel dieser Arbeit ist es, die technologischen Fortschritte physikalisch zu verstehen und gezielte Weiterentwicklungen für spezifische Einsatzgebiete zu ermöglichen. In der untersuchten Hohlkathodenbauform ist das aus Tantal bestehende, vom Arbeitsgas Argon durchströmte Kathodenröhrchen koaxial von einer Ringanode sowie von einer Magnetfeldspule umgeben. Die Entladung wird durch Hochspannungspulse gezündet, worauf sich ein diffuser Bogen im Röhrchen (internes Plasma) ausbildet. Das Röhrchen wird von Plasmaionen auf hohe Temperaturen geheizt, die eine thermionische Emission von Elektronen ermöglichen, welche das Plasma speisen. Das technologisch nutzbare externe Plasma wird im Vakuumrezipienten durch Wechselwirkung der Gasteilchen mit Strahlelektronen aus der Kathode erzeugt. Bei starker Reduktion des Arbeitsgasflusses wird die Entladung durch das Magnetfeld der Spule stabilisiert. Der experimentelle Befund, dass dadurch Plasmadichte und -reichweite sowie ggf. die Ladungsträgerenergien im Rezipienten aufgrund des intensiveren Elektronenstrahls wesentlich gesteigert werden können, wird durch ortsaufgelöste Langmuir-Sondenmessung, optische Emissionsspektroskopie und energieaufgelöste Massenspektrometrie ausführlich belegt und nach der Lösung von Strom- und Wärmebilanzgleichungen durch die Verhältnisse im Kathodenröhrchen begründet. Neben Argon werden auch typische Reaktivgase der Vakuumbeschichtung im Hohlkathodenplasma betrachtet: zum einen Stickstoff und Sauerstoff, die in reaktiven PVD-Prozessen (physikalische Dampfphasenabscheidung) zur Beschichtung mit Oxid- bzw. Nitridschichten zum Einsatz kommen und durch Ionisation, Dissoziation und Anregung im Hohlkathodenplasma verbesserte Schichteigenschaften ermöglichen; zum anderen Azetylen, das bei PECVD (plasmagestützte chemische Dampfphasenabscheidung) von amorphen wasserstoffhaltigen Kohlenstoffschichten z. B. für tribologische oder biokompatible Beschichtungen genutzt wird. Azetylen wird durch Streuprozesse mit Elektronen und Ionen im Plasma aufgespalten, wodurch schichtbildende Spezies erzeugt werden, die am Substrat kondensieren. Durch die Wahl der Plasmaparameter sowie durch abgestimmte Substratbiasspannung und Substratkühlung lassen sich die Beschichtungsrate einstellen sowie polymer-, graphit- oder diamantartige Eigenschaften erzielen. Neben der Plasmadiagnostik mittels energieaufgelöster Massenspektrometrie werden die erzeugten Kohlenstoffschichten vorgestellt und hinsichtlich Härte, Zusammensetzung und Morphologie analysiert
In the present thesis, characterization, modeling and application of a magnetically enhanced hollow cathode arc discharge are presented. Since the 1960s, hollow cathodes are being studied in basic and applied research. At Fraunhofer Institute for Electron Beam and Plasma Technology, further development concerning the application in vacuum coating technology has been carried out for about twenty years. The present work targets on physically understanding the technological progress in order to enable specific further development and application. In the investigated hollow cathode device, a ring-shaped anode and a magnetic field coil are arranged coaxially around the tantalum cathode tube, which is flown through by argon as the working gas. The discharge is ignited by high voltage pulses establishing a diffuse arc within the cathode tube (internal plasma). The cathode is being heated by the plasma ions to high temperatures, which leads to thermionic emission of electrons sustaining the plasma. The external plasma in the vacuum chamber, which can be used for technological applications, is generated by collisions of gas atoms with beam electrons originating from the cathode. In the case of strongly reduced working gas flow, the discharge is stabilized by the magnetic field of the coil; the related experimental findings such as significantly increased plasma density and range as well as higher charge carrier energies in the external plasma are extensively proved by spatially resolved Langmuir probe measurements, optical emission spectroscopy, and energy-resolved ion mass spectrometry. Furthermore, the results are correlated to the conditions within the cathode tube by solving the current and heat balance equations. Besides argon, typical reactive gases used in vacuum coating are examined in the hollow cathode plasma, too. First, nitrogen and oxygen, which are applied in PVD (physical vapor deposition) processes for the deposition of oxide and nitride layers, are ionized, dissociated, and excited by plasma processes. In the case of practical application, this plasma activation leads to improved film properties. Second, acetylene is used as a precursor for PECVD (plasma-enhanced chemical vapor deposition) of amorphous hydrogenated carbon films, e.g. for tribological or biocompatible applications. Acetylene is cracked by electron and ion scattering in the plasma providing film-forming species to be deposited on the substrate. The deposition rate as well as the polymeric, graphitic, or diamond-like properties can be controlled by plasma parameters, a defined substrate bias, and substrate cooling. The hollow cathode-generated acetylene plasma has been characterized by energy-resolved ion mass spectrometry, and the carbon films obtained are analyzed regarding hardness, film composition, and morphology

Les oxydes de cuivre cuxo formes a la surface d'une lame de cuivre sont etudies afin de preciser les mecanismes physiques de la selectivite spectrale et le role joue par chacun des deux oxydes cu2o et cuo. Influence des conditions de preparation et des methodes d'oxydation. Le phosphure de zinc (zn3p2) apparait comme un candidat potentiel pour la realisation de cellules solaires. Elaboration de couches minces a l'etat amorphe ou cristallise. Caracterisation des couches (structure cristalline, etat de surface, composition). Etude des proprietes optiques et electriques

碩士
國立中正大學
物理系研究所
107
We fabricated self-assembled SiO2 opal photonic crystals and deposited TiO2 films with different thickness on their surfaces. We characterized the optical properties of the opal with angularly resolved reflection spectra. We found that besides the reflection peaks resulted from the photonic stop band of the opal in the (111) direction of the face-centered cubic crystalline, we also observed anomalous peaks in shorter wavelength range. Then we investigate their behaviors as a function of TiO2 film thickness, and we found that these reflection peaks behave like Wood’s anomaly that results from the guided mode resonance of the incident light with the corrugated TiO2 films conformed to the opal structure.

碩士
國立臺灣科技大學
電子工程系
87
To design an optical multilayer interference system, it is important to know in advance the optical constants of all the materials used. Generally speaking, the optical constants of the film differ from those of the bulk materials. Therefore, one needs a convenient method to determine the optical constants. In the past many years, measurements of optical constants of thin films have been extensively investigated, which are based on photometric, ellipsometric, interferometric measurements or Kramer- Kronig relation and so on, but these methods are more complicated. Hence we bring up a different method for determining the optical constants of a thin film, which is based on the analytical calculation. Only the measured reflectance extreme and the corresponding transmittance at the same wavelength are required. We will simulate the reflectance and corresponding transmittance of nonabsorbing(SiO2) and weakly absorbing(TiO2) films when the optical thickness of the film is an odd number of quarter wavelengths. Using these spectra data, we calculate the optical constants of SiO2 and TiO2 films successfully by using analytical method. This method is more accurate and simpler than others. Chapter 2 Basic theory 3 2.1 Basic optical formula 4 2.1.1 Normal incidence 4 2.1.1.1 Single surface 4 2.1.1.2 Thin-film coating 5 2.1.2 Oblique incidence 6 2.1.2.1 Single surface 7 2.1.2.2 Thin-film coating 8 2.1.3 Reflection at two or more surfaces 8 2.2 Dispersion equation 9 Chapter 3 Methods of determination of optical constants 16 3.1 General discussion of methods for determination of optical constants 16 3.1.1 Single-wavelength methods 16 3.1.2 Multi-wavelength methods 17 3.2 Analytical method 17 Chapter 4 Simulation and results 24 4.1 Simulation of reflectance and transmittance 24 4.1.1 Nonabsorbing film 24 4.1.2 Weakly absorbing film 33 4.2 Numerical results 42 4.2.1 Nonabsorbing film 42 4.2.2 Weakly absorbing film 43 Chapter 5 Conclusion 44 Bibliography 45

碩士
國立臺灣大學
化學工程學研究所
91
Titania solutions were prepared by thermal hydrolysis, sol-gel method, and obtained from P25-suspension, Hombikat XXS100 and Hombikat UV100WP TiO2 solution (Sachtleben Chemie GmbH Com., Germany). The TiO2 films were coated on glass plates and optical fibers by the dip-coating method. The thickness of films ranged from 60~600 nm after calcinations at 500°C. Process parameters for coating TiO2, such as the concentration of TiO2 solution, the rate of dipping and the times of coating were studies. The films became thicker, and the crystal size increased by increasing the concentration of TiO2 solution, the dipping rate and the numbers of coating. However, films were found crack or aggregate when the film thickness was thick. From SEM micrographs, AFM surface profiles and the ASTM adhesion tests, the films coated by thermal hydrolysis and Hombikat XXS100 solution were among the best, following by the films coated by sol-gel, P25-suspension, and Hombikat UV100WP solution. From the result of XRD, the anatase phase was found for all films. Furthermore, the wavelength of absorption was under 400nm from the UV-Vis spectra. For TiO2 superhydrophilicity property, it was found that the contact angle of water decreased to near zero under UV-light irradiation, and recovered to the initial contact angle in darkness. An optical-fiber reactor (OFR) with TiO2-coated fibers was designed and assembled to transport UV light to fiber-supported TiO2 and conducted a photocatalytic reaction. Gas-phase ammonia was decomposed in the OFR under UV-light irradiation showing a good photocatalytic reactivity of TiO2-coated fibers.

碩士
崑山科技大學
機械工程研究所
96
To solar cell, reducing the reflection rate on the panel surface has been playing a very important role all the time. Using the anti reflection coating to increase the incident light penetration the cell surface is one of best methods. In this study, multilayer nano thin film is coated on the glass of Silicon-based thin film solar cell. It can increase the absorb range of the photo wave length and anti UV ability, and form this obtain better anti reflecting rate and PV transfer rate. This research adopts the thin film analysis software, TFCale, to find out the suitable coating material for anti reflection coating from initial analysis, and figure out the optical properties of single layer and multi layer coatings. In the experiment, a vacuum spatter is adopted to coat the compound layer of dioxide silicon and nitride silicon. By adjust and control the proportion of nitrogen and oxygen and the use of 99.999% purity P type silicon target, the anti reflection coating of multi. layer structure dioxide silicon and nitride silicon is foamed. This design of multilayer coating, can make the absorb spectrum range lie from 380nm to 1200nm. In visible light spectrum range of 380nm to 780nm, the average penetration rate reaches 93%. Relative to 90% of uncoated glass, the average penetration rate increases 3%. And same coating on the TCO glass, in visible light spectrum range of 380nm to 780nm, the average penetration rate reaches 68.4%, relative to 67.6% of uncoated glass, the average penetration rate increases 0.8%; in spectrum range of 570nm to 640nm, the average penetration rate reaches 75.4%, relative to 67.6% of uncoated glass, the average penetration rate increases 8%.

碩士
國立虎尾科技大學
材料科學與綠色能源工程研究所
101
The thersis is investigated on the application of Cu1ZnxSn1-xSe2 for solar cell absorber layer materials.In this study on copper,zinc, tin, selenium the four elements of the target, prepared by melting into the quaternary mixture,The ink is prepared using wet-ball milling,three categories of ink were x=0.3,x=0.5,x=0.7,by spin coating.The precursor layer is placed in RTP furnace, and then heated at the temperature between 400℃and 600℃ to form the compound layer with Kesterite structure that fabricating CZTSe thin film without long heat treatment and selenization. Finally elemental composition of films was determined using EDS, surface morphology and cross-section of the films were observed by SEM, and crystal structure was analyzed by XRD optical properties of films was recorded using UV-vis-NIR spectrophotometer, the band gap energy. Based on the analysis results of this experiment x=0.7,CZTSe. thin film with Kesterite structure can be obtained by heating at 500℃ for 10 minutes. show higher crystallinity with a larger grain size,and the band gap is 1.14eV.

碩士
國立臺灣科技大學
自動化及控制研究所
93
The objective of this research is to study an innovative lithography using the effect of thermal-induced super resolution, and to demonstrate that the technique can effectively reduce the exposed pit width on the photoresist layer. The technique makes use of a thin metallic mask layer deposited on the top of the photoresist layer. After illuminating with a focused laser beam, the mask layer opens an aperture in melting temperature area around the center of the laser spot. Because the aperture size is much smaller than the laser spot and the optical properties of solid mask layer are different from those of melting one, the intensity distribution of the transmission light would become narrower than that of the incident light and forms a below spot size. Can be found from the result of imitating, the range plating the indium membrane and reducing with the width of the mark not plating the indium can have been up to about 15%, but because simulation this processing depth too shallow, so FWHM to is it have trend of increase instead to reduce while being wide. This text to adjust probe bore and exposure time and power and development time and indium thin film thickness and energydensity above parameter. To observe this parameter of effect for pit width and FWHM. According to the simulation results, Indium thin film with a range of thickness 10 nm was evaporated on the photoresist layer as metallic mask layer. the pit width on the photoresist layer could be shrunk by more than 15% and FWHM could be shrunk 2.2%.

Die vorliegende Dissertation behandelt Charakterisierung, Modellbildung sowie Anwendung einer magnetfeldgestützten Hohlkathoden-Bogenentladung. Hohlkathoden sind seit den 1960er Jahren Gegenstand grundlagen- sowie anwendungsorientierter Forschung und werden seit 20 Jahren am Fraunhofer-Institut für Elektronenstrahl- und Plasmatechnik für die Anwendung auf dem Gebiet der Vakuumbeschichtung weiterentwickelt. Ziel dieser Arbeit ist es, die technologischen Fortschritte physikalisch zu verstehen und gezielte Weiterentwicklungen für spezifische Einsatzgebiete zu ermöglichen. In der untersuchten Hohlkathodenbauform ist das aus Tantal bestehende, vom Arbeitsgas Argon durchströmte Kathodenröhrchen koaxial von einer Ringanode sowie von einer Magnetfeldspule umgeben. Die Entladung wird durch Hochspannungspulse gezündet, worauf sich ein diffuser Bogen im Röhrchen (internes Plasma) ausbildet. Das Röhrchen wird von Plasmaionen auf hohe Temperaturen geheizt, die eine thermionische Emission von Elektronen ermöglichen, welche das Plasma speisen. Das technologisch nutzbare externe Plasma wird im Vakuumrezipienten durch Wechselwirkung der Gasteilchen mit Strahlelektronen aus der Kathode erzeugt. Bei starker Reduktion des Arbeitsgasflusses wird die Entladung durch das Magnetfeld der Spule stabilisiert. Der experimentelle Befund, dass dadurch Plasmadichte und -reichweite sowie ggf. die Ladungsträgerenergien im Rezipienten aufgrund des intensiveren Elektronenstrahls wesentlich gesteigert werden können, wird durch ortsaufgelöste Langmuir-Sondenmessung, optische Emissionsspektroskopie und energieaufgelöste Massenspektrometrie ausführlich belegt und nach der Lösung von Strom- und Wärmebilanzgleichungen durch die Verhältnisse im Kathodenröhrchen begründet. Neben Argon werden auch typische Reaktivgase der Vakuumbeschichtung im Hohlkathodenplasma betrachtet: zum einen Stickstoff und Sauerstoff, die in reaktiven PVD-Prozessen (physikalische Dampfphasenabscheidung) zur Beschichtung mit Oxid- bzw. Nitridschichten zum Einsatz kommen und durch Ionisation, Dissoziation und Anregung im Hohlkathodenplasma verbesserte Schichteigenschaften ermöglichen; zum anderen Azetylen, das bei PECVD (plasmagestützte chemische Dampfphasenabscheidung) von amorphen wasserstoffhaltigen Kohlenstoffschichten z. B. für tribologische oder biokompatible Beschichtungen genutzt wird. Azetylen wird durch Streuprozesse mit Elektronen und Ionen im Plasma aufgespalten, wodurch schichtbildende Spezies erzeugt werden, die am Substrat kondensieren. Durch die Wahl der Plasmaparameter sowie durch abgestimmte Substratbiasspannung und Substratkühlung lassen sich die Beschichtungsrate einstellen sowie polymer-, graphit- oder diamantartige Eigenschaften erzielen. Neben der Plasmadiagnostik mittels energieaufgelöster Massenspektrometrie werden die erzeugten Kohlenstoffschichten vorgestellt und hinsichtlich Härte, Zusammensetzung und Morphologie analysiert.
In the present thesis, characterization, modeling and application of a magnetically enhanced hollow cathode arc discharge are presented. Since the 1960s, hollow cathodes are being studied in basic and applied research. At Fraunhofer Institute for Electron Beam and Plasma Technology, further development concerning the application in vacuum coating technology has been carried out for about twenty years. The present work targets on physically understanding the technological progress in order to enable specific further development and application. In the investigated hollow cathode device, a ring-shaped anode and a magnetic field coil are arranged coaxially around the tantalum cathode tube, which is flown through by argon as the working gas. The discharge is ignited by high voltage pulses establishing a diffuse arc within the cathode tube (internal plasma). The cathode is being heated by the plasma ions to high temperatures, which leads to thermionic emission of electrons sustaining the plasma. The external plasma in the vacuum chamber, which can be used for technological applications, is generated by collisions of gas atoms with beam electrons originating from the cathode. In the case of strongly reduced working gas flow, the discharge is stabilized by the magnetic field of the coil; the related experimental findings such as significantly increased plasma density and range as well as higher charge carrier energies in the external plasma are extensively proved by spatially resolved Langmuir probe measurements, optical emission spectroscopy, and energy-resolved ion mass spectrometry. Furthermore, the results are correlated to the conditions within the cathode tube by solving the current and heat balance equations. Besides argon, typical reactive gases used in vacuum coating are examined in the hollow cathode plasma, too. First, nitrogen and oxygen, which are applied in PVD (physical vapor deposition) processes for the deposition of oxide and nitride layers, are ionized, dissociated, and excited by plasma processes. In the case of practical application, this plasma activation leads to improved film properties. Second, acetylene is used as a precursor for PECVD (plasma-enhanced chemical vapor deposition) of amorphous hydrogenated carbon films, e.g. for tribological or biocompatible applications. Acetylene is cracked by electron and ion scattering in the plasma providing film-forming species to be deposited on the substrate. The deposition rate as well as the polymeric, graphitic, or diamond-like properties can be controlled by plasma parameters, a defined substrate bias, and substrate cooling. The hollow cathode-generated acetylene plasma has been characterized by energy-resolved ion mass spectrometry, and the carbon films obtained are analyzed regarding hardness, film composition, and morphology.