FIB is currently the economic methods to produce nano-structure below 100nm. In the past, FIB manufactures nano-structure patterns also unsatisfactory. In this study, the influence of twice deposited mask layer on the aspect ratio of nano-structure and verticality of side wall contour was discussed. The single mask layer is used for pattern transfer. Pattern distortion may occur during etching due to several factors like improper parameter setting, limitation of machine table, etc. The most common situations are aciculate and salient shape on the top and angle of slope which is too big to be vertical. In order to improve above-mentioned situations, a mask layer of multi-deposition was designed to protect the side wall so that it could retard etching. In addition to modifying verticality of side wall, the aspect ratio could be raised indirectly because the second deposition had reduced the interval between patterns. In the aspect of using machine table, the first mask layer, chromium, which was deposited by the sputtering machine. And the etching pattern was directly written on the first mask layer by focused ion beam. The silicon was uncovered at etched place, and then the second mask layer, silica (SiO2), which was deposited by the sputtering machine. The surface contour was directly covered with silica layer. Right after that, the top and bottom of silica were removed through vertical etching by inductively coupled plasma machine. The silica on the side wall of structure was retained to protect the side wall and raise aspect ratio. Eventually, the silicon was etched by the same way of inductively coupled plasma machine that it was researched on the difference in etching gas. And there was a comparison between chlorine and fluorine gases. After optimizing parameters, the nano-structure was made under 100nm.

Magnetic nano-clusters in silicon involving iron and cobalt were synthesized using low energy (50 keV) ion implantation technique and post-implantation thermal annealing. Before the irradiation, multiple ion-solid interaction simulations were carried out to estimate optimal ion energy and fluence for each experiment. For high-fluence low-energy irradiation of heavy ions in a relatively lighter substrate, modeling the ion irradiation process using dynamic code SDTrimSP showed better agreement with the experimental results compared to the widely used static simulation code TRIM. A saturation in concentration (~ 48%) profile of the 50 keV Fe or Co implants in Si was seen at a fluence of ~ 2 × 1017 ions/cm2. Further study showed that for structures with a curved surface, particularly for nanowires, better simulation results could be extracted using a code "Iradina" as the curve geometry of the target surface can be directly defined in the input file. The compositional, structural, and magnetic properties were studied using Rutherford backscattering spectrometry, X-ray photoelectron spectroscopy, X-ray diffraction, atom probe tomography, and vibrating sample magnetometry. Irradiation of high-current (~ 2 μA/cm2) 50 keV Fe ions into Si at a fluence of 2 × 1017 ions/cm2 showed the formation of Fe5Si3 nano structures in the near-surface region of the substrate. Post-implantation thermal annealing in vacuum at 500 οC for one hour showed a significant enhancement in structural and magnetic properties. Similar high-current irradiation of 50 keV Co with a fluence of 3.2 × 1016 ions/cm2 into Si substrate showed the formation of superparamagnetic structure even at room temperature in the as-implanted samples. The simulation results for irradiation of Co and Fe on the curved surface were validated by ion irradiation on pre-fabricated Si nano tip followed by atom probe tomography analysis.

Abstract Negative index structures could be implemented through surface Plasmon polariton waves generated by nanostructures. We are interested in PMMA grating structure on curved metal surface. In order to fabricate this kind of samples, a series process parameters have been tested and also the lift-off process has been developed. Our results show superlens effect under optical microscope(OM). The sub-wavelength grating image is reconstructed in the non-grating region where the PMMA dielectric layer is not uniform. Surface Plasmon(SPP) waves generated in the grating region propagate to the non-grating region and are scattered out through the non-uniform PMMA layer. The grating information is not resolvable under OM but clear in the reconstructed region. It shows that SPP waves can show super resolution and a simple batch process should be developed in the future.

The microstructure and electrochemical behavior of boron doped and undoped ultra thin diamond film electrodes have been studied in this work. The ultra thin diamond films are deposited on porous silicon (PSi) by microwave plasma chemical vapor deposition (MPCVD). In order to enlarge the surface area of diamond electrodes, the deposition of nano structured diamond thin films is performed only in a short time deposition under a negative bias, so that diamond nuclei grew from the tips of PSi nano structures and the thin film surface remained rough and nano fine structured. Diamond thin films were analyzed by Raman spectroscopy and SEM, and then fabricated to the electrode device. From SEM analysis, the morphology of diamond thin films on PSi reveals in the shape of nano rods diamond crystallites. The electro-chemical response was evaluated by performing cyclic voltammetry in the inorganic K4[Fe(CN)6] and a K2HPO4 buffer solution. Boron doped diamond thin film on porous silicon has demonstrated a high redoxidation current of cyclic voltammetry, which may be due to the rough surface providing more electrochemical surface area and more sp2 conducting bonds exposed on the surface.

In this thesis, the leakage-mechanism after O2-plasma treatments was investigated. And the mechanism is transformed from Schottky emission into ionic conduction due to moisture uptake after porous silica film undergoes O2 plasma ashing. Besides, CMP process can to recover the damaged films by removed the degraded parts. From the result, we know that O2 plasma causing the bulky damage. Finally, the resistance of metal penetration of O2 plasma treated POSG is performed by utilizing BTS test. It was found that the moisture uptake in POSG films assisting metals in ionization process. Then, the penetrated metal ions in POSG film causes the leaky characters degraded.

The fabrication characteristic of focused ion beam (FIB) for fused quartz was investigated. With the progress of nanotechnology, new technologies and devices are invented constantly. In nanofabrication, FIB has several advantages such as high material removal rate, high resolving power and direct fabrication in some selected areas without etching mask. Therefore, it had been studied in detail to fabricate nano-structures by FIB. In this study, we found out the effect of nano-machining by adjusting the parameters of FIB system such as: beam current, overlap, and dwell time. The fabricated features together with their surface morphology and profile were investigated by scanning electron microscope (SEM) and atomic force microscope (AFM). Results show that when beam current was smaller, overlap was 50% and dwell time was 10£gs could get best performance by FIB.

Highly repellent surfaces are constantly being sought in a number of industrial sectors, where accumulation of unwanted material (ice, debris, insects etc…) can cause seriously detrimental effects on these function. The chemistry and physics of such surfaces is relatively well-understood, yet their industrial adoption is still very limited, due to their poor durability. Emerging technologies for nanostructured coatings have significant potential for the development of advanced surfaces, where high repellency can be combined with mechanical robustness. However, lack of understanding of the wear mechanism in such coatings and lack of recognised test methodologies to enable comparison of various approaches hinders effective progress in advanced surfaces development. Furthermore, there is no comprehensive classification system that allows categorization of highly repellent surfaces. New multi-variable analysis methodology for the evaluation of durability in highly repellent coatings was developed in this study. Key coating parameters were identified, including initial wettability, abrasive wear, adhesive wear and ability to retain repellency. Coating characteristics were examined with FTIR, SEM, AFM, DSA, Taber Abrader, roughness profilometer and goniometer. Furthermore, these characteristics were presented in a form of spider diagrams and performance indices and are used to generate plot of performance indices. In this study, six types of TWI coating anti-soiling materials (based on patented TWI’s Vitolane® technology, containing silsesqioxanes and functionalized silica nanoparticles) and two commercial easy clean products were prepared and subjected to new assessment methodology. It has been found that this novel methodology for evaluation of highly repellent surfaces allows comparison and categorizing different families of coatings. The data obtained from plot of performance indices supports the statement that there is an inverse relation between repellency and durability of hydrophobic surfaces. It has been found that coatings with low Ra value (no more than 10nm) and symmetric distribution of peaks and valleys are the most durable, yet their WCA value doesn’t exceed more than 105°. It has been also found that some nanostructured coatings behave beyond this inverse relationship. Addition of novel inorganic building blocks with controlled size (Ra in a range of 200nm and symmetric distribution in roughness profile) and functionalities (3-(trimethoxysilyl)propyl methacrylate and 1H 1H 2H 2H-perfluorooctyltriethoxysilane) improves overall coating performance by linking mechanical robustness with desired wetting characteristics (WCA reaches 112°C). The progress in testing and classification criteria of repellent coatings enables further development of next generation of materials. This novel knowledge-based approach for highly repellent coatings validation has the potential to accelerate uptake. The findings open a promising new direction in materials development, where advanced coatings and surface treatments can be developed by design, reducing the number of development iterations, ultimately leading to reduced cost and development time.

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第15389号 / 工博第3268号 / 新制||工||1492(附属図書館) / 27867 / 京都大学大学院工学研究科物質エネルギー化学専攻 / (主査)教授 江口 浩一, 教授 井上 正志, 教授 垣内 隆 / 学位規則第4条第1項該当

Le champ biomédical n’a pas échappé à l’évolution de la technologie, elle cherche aussi à intégrer plusieurs fonctions dans un espace restreint. Un des points forts du développement est la massification de points de service, afin d'obtenir un diagnostic rapide des maladies. Le diagnostique aux premières étapes de son évolution permettra réduire considérablement les coûts associés aux traitements des patients. Le présent document exprimera une alternative à l'évolution de la technologie des biocapteurs qui sont basés sur le phénomène optique appelé résonance par plasmons de surface. Ce projet de recherche vise l’étude de l’intégration monolithique des deux tiers des composants principaux qui conforment normalement à ce type de biocapteurs optiques. Tandis que d'autres projets de recherche ont centré leurs travaux sur l’intégration de la surface de réaction et le détecteur, notre travail a pris en compte l’intégration de la source de lumière et la surface de réaction biologique. Deux types de sources ont été employés au moment de faire la conception, l’étude de matériaux, la fabrication et la caractérisation de la performance de notre dispositif. La première source a employé des puits quantiques à l’intérieur d’une gaufre de GaAs qui nécessitait un pompage optique pour son fonctionnement. La deuxième source a eu une gaufre commerciale employée pour la fabrication des diodes d’émission lumineuse verticale, qui a dû être excitée par un courant électrique. On a découvert que les deux types de sources sont complémentaires. La source avec des puits quantiques a démontré une amélioration de la performance en comparaison à notre système commercial de référence. La deuxième source a démontré la faisabilité d’intégration monolithique en permettant se rapprocher à la fabrication d’un prototype commercial. La porte reste donc ouverte pour la poursuite du développement de cette technologie en cherchant un nouveau système employant ces deux sources, mais usant de meilleures caractéristiques.

Current micro-scale electronics technology has been approaching rapidly towards its technological limit. This has shifted the focus towards nano-scale technology in recent years. More and more researchers around the globe are working in pursuit of bringing nano-scale technology into mainstream. The research carried out here is a small step towards a similar goal. The remarkable optical properties exhibited by certain nano-scale structures are in stark contrast to their bulk form and this provides the basis for this research. Two kinds of nanostructures are developed and investigated for their optical properties. One of these is nanofibers processed from a polymer known as polyaniline (PANI). The focus of this study is to investigate its optical and conductive properties under different conditions of doping environments, temperature and polymerization conditions. Optical characterization technique such as UV-Visible spectroscopy is developed to carry out the investigation. The developed nanofibers have been demonstrated to possess optical and conductive properties to be dependent on doping variables. Study of these optical properties could prove very useful in the development of electrochromic devices and gas sensors. Later in the research, UV-Visible spectroscopy has been improved into a low cost Raman spectroscopy setup which is validated by experimentation carried out on some samples. The second type of nano-structure developed and investigated, is an array of nanoparticles of noble metals such as gold and silver. Such an array is shown to exhibit a phenomenon called plasmon resonance effect when excited by light. UV-Visible spectroscopy technique is utilized to investigate this effect for metal nano-arrays. A biologically nano-structured surface (wing of an insect called cicada) is used as the substrate for the fabrication of metal array. A serious attempt has also been made to do 'Surface Enhanced Raman Spectroscopy (SERS)', making use of the metal nano-array developed. This technique improves the raman lines intensities of certain less sensitive samples such as thiophenol, which are known to give weak raman lines. This is carried out by adsorbing the sample on the metal nano-array.