Spelling suggestions: "subject:"proximity"" "subject:"nroximity""
251 |
Mass spectra of halogenostyrylbenzoxazolesAyrton, Stephen T., Panova, Jekaterina, Michalik, Adam R., Martin, William H.C., Gallagher, R.T., Bowen, Richard D. 20 August 2012 (has links)
No / Several series of styrylbenzoxazoles of general formula XC6H3(NCO)CH=CHC6H4Y [X= F, Cl or Br; Y = H, F, Cl, Br, CH3 or CH3O] have been investigated by positive ion electrospray and electron ionization mass spectrometry. These compounds, many of which are biologically active or have pharmaceutical potential, show in their electrospray spectra strong peaks for MH+ ions, which undergo relatively little fragmentation. The electron ionization spectra are extremely clean, being dominated by the loss of an atom or radical, Y*, from the ortho position of the pendant ring, by a rearrangement that may be interpreted as a proximity effect. The resultant [M-Y](+) ions are exceptionally stable and rarely undergo further fragmentation. The analytical value of this proximity effect, which is analogous to intramolecular aromatic substitution, in revealing the presence of a substituent in the pendant ring and determining its position, is emphasized. Elimination of a species (including H* or F*) derived from an ortho substituent in the pendant ring occurs even when apparently more favourable alternative fragmentation is possible by direct cleavage of the C-X bond (X = Cl or Br) in the benzoxazole ring.
|
252 |
Locations of LTL-logistics service providers as urban consolidation centers in Western GermanyThiemermann, Andre, Holthaus, Tim, Mayregger, Patrick, Leerkamp, Bert 06 May 2024 (has links)
Proximity logistics represent a counter movement to logistics sprawl – the return of logistics to urban areas. In the case presented, a logistics service provider in the groupage and less-than-truckload (LTL) segment runs an urban consolidation center (UCC), offers receiver-led consolidation and additional service like stockholding to inner-city businesses in the city of Dusseldorf. The case shows that for the development of a UCC or a proximity logistics facility to succeed, no expensive space is necessarily required in immediate inner-city areas. The transfer to other locations of logistics service providers of the same segment shows that these could serve as possible locations for UCC in terms of cargo bike-relevant distances. We therefore conclude that the relevant locations of logistics infrastructure like ports and centrally located logistics facilities should be seen as crucial for the transformation to
sustainable freight transport and its initiation by municipal governments.
|
253 |
Nanoscale investigation of superconductivity and magnetism using neutrons and muonsRay, Soumya Jyoti January 2012 (has links)
The work presented in this thesis was broadly focussed on the investigation of the magnetic behaviour of different superconducting materials in the form of bulk (singe crystals and pellets) and thin films (nanomagnetic devices like superconducting spin valves etc). Neutrons and muons were extensively used to probe the structural and magnetic behaviour of these systems at the nanoscale along with bulk characterisation techniques like high-sensitive magnetic property measurements, scanning probe microscopy and magneto-transport measurements etc. The nanoscale interplay of Superconductivity and Ferromagnetism was studied in the thin film structures using a combination of Polarised Neutron Reflectivity (PNR) and Low Energy Muon Spin Rotation (LE-µSR) techniques while bulk Muon Spin Rotation (µSR) technique was used for microscopic magnetic investigation in the bulk materials. In the Fe/Pb heterostructure, evidence of the Proximity Effect was observed in the form of an enhancement of the superconducting penetration depth (λs) with an increase in the ferromagnetic layer thickness (dF) in both the bilayered and the trilayered structures. The existence of an Inverted Magnetic Region was also detected at the Ferromagnet-Superconductor (F/S) interface in the normal state possibly originating from the induced spin polarisation within the Pb layer in the presence of the neighbouring Fe layer(s). The spatial size (height and width) of the Inverted Magnetic Region did not change much while cooling the sample below the superconducting transition temperature(Tc)and it also stayed unaffected by an increase in the Fe layer thickness and by a change of the applied magnetic field. In the superconducting spin valve structure containing Permalloy (Py) as ferromagnetic layer and Nb as the superconducting layer, LE-µSR measurements revealed the evidence of the decay of magnetic flux density (as a function of thickness) within the Nb layer symmetrically from the Py/Nb interfaces towards the centre of the Nb layer in the normal state. The thickness dependent magnetisation decay occurred over two characteristic length scales in the normal state that stayed of similar values in the superconducting state also. In the superconducting state, an additional contribution towards the magnetisation was found in the vicinity of the Py/Nb interfaces possibly originating from the spin polarisation of the singlet Cooper pairs in these areas. The nanoscale magnetic investigation on a highly engineered F/S/F structure (where each of the F blocks made of multiple Co/Pd layers with magnetic moments aligned perpendicular to the plane of these layers and neighbouring magnetic blocks separated by Ru layers giving rise to antiferromagnetic alignment) using LE-µSR showed an antisymmetric thickness dependent magnetic flux density profile with two characteristic length scales. In the superconducting state, the magnetic flux density profile got modified within the superconducting Nb₆₇Ti₃₃ layer near the F/S interfaces in a way similar to that of observed in the case of Py/Nb system, most likely because of the spin polarisation of the superconducting electron pairs. The vortex magnetic phase diagram of Bi₂Sr₂Ca₂Cu₃O10-δ was studied using the Muon Spin Rotation (µSR) technique to explore the effects of vortex lattice melting and rearrangements for vortex transitions and crossover as a function of magnetic field and temperatures. At low magnetic fields, the flux vortices undergo a first order melting transition from a vortex lattice to a vortex liquid state with increasing temperature while another transition also occurred with increasing field at fixed temperature to a vortex glass phase at the lowest temperatures. Evidence of a frozen liquid phase was found in the intermediate field region at low temperature in the form of a lagoon in the superconducting vortex state which is in agreement with earlier observations made in BiSCCO-2212. The magnetic behaviour of the unconventional superconductor Sr₂RuO₄ was investigated using µSR to find the evidence of normal state magnetism and the nature of the vortex state. In the normal state, a weak hysteretic magnetic signal was detected over a wide temperature and field range believed to be supporting the evidence of a chiral order parameter. The nature of the vortex lattice structure was obtained in different parts of the magnetic phase diagram and the evidence of magnetic field driven transition in the lattice structure was detected from a Triangular→Square structure while the vortex lattice stayed Triangular over the entire temperature region below Tc at low fields with a disappearance of pinning at higher temperatures.
|
254 |
Regional airspace design: a structured systems engineering approachFulton, Neale Leslie, Aerospace & Mechanical Engineering, Australian Defence Force Academy, UNSW January 2002 (has links)
There has been almost fifteen years of political controversy surrounding changes to the rules and procedures by which aircraft conduct their flight within regional Australia. Decisions based on a predominately heuristic (rule of thumb) approach to design have had many adverse consequences for the integrity of the proximity warning function. A sound mathematical model is required to establish this function on a mature engineering foundation. To achieve this, the proximity warning function has been investigated as a hybrid-system. This approach recognises the dual nature of the design: that aircraft dynamics give rise to continuous mathematical models while the communication protocols controlling proximity require discrete mathematical approaches. The blending of each aspect has yielded a deeper insight into the operational limitations and failure modes of this function. The presentation of the thesis follows a design thread through the function. It begins with a description of existing standards and implementations. Risk models are then developed. The pilot interface is recognised as a primary design constraint. Mathematical models are then developed to describe the topology of flow, proximity dynamics, and the scheduling constraints associated with visual, voice, and data-link communications required by the proximity warning function. These analyses show that many aspects of design can be bounded by analytical formulae that bring new robustness to the design and resolve some of the misconceptions arising from the often inaccurate perceptions of present airspace operations. Failure modes, unaccounted for in existing designs are found to actually aggravate failure in the very situations in which the airspace design should be robust and should act to prevent collisions. In particular, there are divergences of performance between the demands required by the system design and the ability of the pilot to deliver such performances. In some cases, these failures may be traced to policy decisions such as service between Instrument Flight Rule and Visual Flight Rule category aircraft. On the basis of the conclusions of this research, a formal engineering review of the proximity warning function is required to assure the containment of the likelihood of mid-air collision for all future operations.
|
255 |
鄰近性、吸收能力與廠商創新績效之研究 / Proximity, absorptive capacity, and innovation performance of firms陳泓汝 Unknown Date (has links)
知識經濟的時代,創新已成為廠商競爭優勢的主要來源。知識的創造、傳遞、轉化和應用,促成廠商創新活動的產生。同時,連結地域空間與廠商創新績效的研究,已成為近代區域經濟與產業發展的重要議題。又,研究者逐漸意識到廠商個體的異質性,進而探求個別廠商的內部能力,吸收能力即成為研究焦點之一。
基此,本研究以全台灣生物技術產業為研究對象,透過廠商問卷之發放,運用因素分析與結構方程模型為分析工具,探討鄰近性-地理鄰近性和組織鄰近性的內涵,以及吸收能力如何扮演外部知識與廠商內部能力的介面,並結合外部知識、內部吸收能力與創新績效之影響路徑。
所得結果如下:
1.從外部知識層面,地理鄰近性扮演重要角色。對於組織鄰近性、創新績效有正面影響效果。其中,組織鄰近性隱含了組織網絡與社會網絡的成分;
2.觀察外部知識與內部能力的連結,外部知識獲取對於吸收能力有正面影響效果;
3.吸收能力對於創新績效亦有正向影響關係;
4.然而,考量到外部知識因素時,吸收能力對於創新績效的效果轉為正向卻不顯著,外部知識直接影響創新績效。
關鍵字:地理鄰近性、組織鄰近性、產業網絡、吸收能力、創新績效 / In the knowledge-based economy, innovation has become a key source of firms’ competitive advantage.The process of knowledge creation, transmission, transformation and application promotes the innovative activities. Meanwhile, the link geographical proximity and innovation performance of firms has become a modern issue of regional economic and industrial study. Also, the researchers gradually realized that the heterogeneity of individual firms, and then pay more ateentionon the internal capabilities of individual firms, thence the absorptive capacity seems to be a decisive element.
Our research regards bio-technology industry as the subject promptly.Through sending questionnaires and using factor analysis and structural equation modeling as analysis tool, we observe “proximity” – the nature of geographical proximity and organizational proximity, and how can absorptvie capacity play the interface role between external knowledge and internal capacity, and further connect the external knowledge with internal absorptive capacity and innovation performance.
The major results of study were found:
1. In the respect of external knowledge, geography proximity plays a crucial role in affecting organizational proximity and innovation performance.
2. External knowledge has a positive influence on absorptive capacity.
3. On the other hand, absorptive capacity affects the innovation permance of firms.
4. However, concerning the external knowledge, absorptive capacity results to positive but not significant on innovation performance.It implies that external knowledge directly impacts on innovation performance.
Keyword:Geographical proximity, Organizational proximity, Industerial network, Absorptive capacity, Innovation performance
|
256 |
Diminution of the lithographic process variability for advanced technology nodes / Diminution de la variabilité du procédé lithographique pour les noeuds technologiques avancésSzucs, Anna 10 December 2015 (has links)
A l’heure actuelle, la lithographie optique 193 nm arrive à ces limites de capacité en termes de résolution des motifs dans la fenêtre du procédé souhaitée pour les nœuds avancés. Des lithographies de nouvelle génération (NGL) sont à l’étude, comme la lithographie EUV (EUV). La complexité de mise en production de ces nouvelles lithographie entraine que la lithographie 193 nm continue à être exploitée pour les nœuds 28 nm et au-delà. Afin de suivre la miniaturisation le rôle des techniques alternatives comme le RET (en anglais Resolution Enhancement Technique) tels que l’OPC (Optical Proximity Correction) est devenu primordial et essentiel. Néanmoins, la complexité croissante de design et de la variabilité du procédé lithographique font qu’il est nécessaire de faire des compromis. Dans ce contexte de complexité croissante du procédé de fabrication, l’objectif de la thèse est de mettre en place une méthode de boucles de correction des facteurs de variabilité. Cela signifie une diminution de la variabilité des motifs complexes pour assurer une résolution suffisante dans la fenêtre de procédé. Ces motifs complexes sont très importants, car c’est eux qui peuvent diminuer la profondeur du champ commune (uDoF). Afin d'accomplir cette tâche, nous avons proposé et validé un enchainement qui pourra être plus tard implémenté en production. L’enchainement en question consiste en une méthodologie de détection basée sur la simulation des motifs les plus critiques étant impactés par les effets issus de la topographie du masque et du profil de la résine. En outre cette méthodologie consiste en une diminution et la compensation de ces effets, une fois que ces motifs les plus critiques sont détectés. Le résultat de l’enchaînement complété sont encourageants : une méthode qui détecte et diminue les variabilités du processus lithographique pour des nœuds de technologie de 28nm a été validée. En plus elle pourrait être adaptée pour les nœuds au-delà de 28 nm. / The currently used 193 nm optical lithography reaches its limits from resolution point of view. Itis despite of the fact that various techniques have been developed to push this limit as much aspossible. Indeed new generation lithography exists such as the EUV, but are not yet reliable to beapplied in mass production. Thus in orders to maintain a robust lithographic process for theseshrunk nodes, 28 nm and beyond, the optical lithography needs to be further explored. It ispossible through alternatives techniques: e.g. the RETs (Resolution Enhancement Techniques),such as OPC (Optical Proximity Correction) and the double patterning. In addition to theresolution limits, advanced technology nodes are dealing with increasing complexity of design andsteadily increasing process variability requiring more and more compromises.In the light of this increasing complexity, this dissertation work is addressed to mitigate thelithographic process variability by the implementation of a correction (mitigation) flow exploredmainly through the capability of computational lithography. Within this frame, our main objectiveis to participate to the challenge of assuring a good imaging quality for the process windowlimiting patterns with an acceptable gain in uDoF (usable Depth of Focus).In order to accomplish this task, we proposed and validated a flow that might be laterimplemented in the production. The proposed flow consists on simulation based detectionmethodology of the most critical patterns that are impacted by effects coming from the masktopography and the resist profile. Furthermore it consists of the mitigation and the compensationof these effects, once the critical patterns are detected. The obtained results on the completedflow are encouraging: a validated method that detects the critical patterns and then mitigates thelithographic process variability been developed successfully.
|
257 |
Nouvelles formes de valorisation territoriale en agriculture : le cas de l’arboriculture de la moyenne vallée du Rhône / News forms of territorial valorization in agriculture : the case of the arboriculture in the middle Rhône valleyPraly, Cécile 30 June 2010 (has links)
L’arboriculture de la Moyenne Vallée du Rhône, concurrencée par les pays à faible coût de production, subit une importante crise structurelle. Dans ce contexte, nous interrogeons les liens existants entre l’arboriculture et ses territoires. Ils peuvent en effet constituer des ressources mobilisées par les acteurs locaux pour développer des formes de valorisation territoriale.Le modèle productif historique de l’arboriculture de la Moyenne Vallée du Rhône, celui de bassin de production-expédition, est aujourd’hui remis en question par deux tensions opposées. La première, dite « centrifuge », est exercée par les principaux expéditeurs qui élargissent leur aire d’approvisionnement au-delà de celle du bassin de production pour être capables d’offrir des volumes de fruits standardisés satisfaisant à la demande des grands distributeurs. A l’inverse, un ensemble de tensions « centripètes » produisent un effet de morcellement interne au bassin, résultant des initiatives d’identification territoriale des fruits portées par les producteurs. A l’intersection de ces tensions, les arboriculteurs développent des stratégies pour maintenir la viabilité économique de leurs exploitations. La tendance est d’ajouter aux circuits d’expédition existants de nouveaux débouchés qui valorisent plusieurs proximités entre production et consommation. Nous décrivons ainsi des « circuits de proximité » pluriels et multi-scalaires, où interviennent différents types de professionnels (grossistes, détaillants, IAA), de consommateurs (habitants ou plus éloignés) et de modes de commercialisation. S’articulant entre concurrence et complémentarité au bassin de production-expédition, ces circuits bénéficient de soutiens de la part des collectivités territoriales. La conclusion de la thèse propose une caractérisation des différents circuits de proximité ainsi qu’un cadre théorique pour penser la diversité des formes de valorisation territoriale en agriculture. / The fruit growing sector in the Middle Rhône Valley, competed by low-cost-production countries, faces a serious structural crisis. Then, we analyze the links between the arboriculture and its territories which can constitue resources mobilized as territorial valorization forms by local actors.The historic productive model of the arboriculture in the Middle Rhône Valley, the production-shipping basin, is now questioned by two rival forces. The first, called « centrifugal », is exercised by the main shippers who enlarge their supply area to be able to deliver large volumes of standardized fruits, relevant for the main retailers demand. In the opposite, some « centripetal » forces produce a fragmentation effect in the basin. These result from territorial identification initiatives for fruits, lead by the producers.Between these forces, farmers develop some strategies to maintain economic viability of their farms. They add to the existing shipping-circuits news outlets which valorize various proximities between production and consumption. We describe multi-scale « proximity circuits », including different types of the fruits supply chain actors, of consumers and marketing chanels. These circuits are shaped by competition and complementarity relationships with the basin of production-shipping. They benefit from the local communities supports.The conclusion of the research displays a characterization of the different proximity circuits and a theorical model to analyze the diversity of territorial valorization forms in agriculture.
|
258 |
Kombinovaná elektronová litografie / Combined Electron Beam LithographyKrátký, Stanislav January 2021 (has links)
This thesis deals with grayscale e-beam lithography and diffractive optical elements fabrication. Three topics are addressed. The first topic is combined grayscale e-beam lithography. The goal of this task is combining exposures performed by two systems with various beam energies. This combined technique leads to a better usage of both systems because various structures can be more easily prepared by one electron beam energy than by the other. The next topic is the optimization of shape borders of exposing structures that are defined by image input. The influence of such optimization on exposure data preparation is evaluated, as well as the exposure time and the change of optical properties of testing structures. The possibility of deep multilevel diffractive optical element fabrication in plexiglass blocks is researched as the third topic. Plexiglass can replace the system of a resist and a substrate. A new approach to writing down the structures by electron beam is presented, minimizing thermal stress on the plexiglass block during the exposure. The writing method also improves the homogeneity of exposed motifs. A method for computing the exposure dose for specific multilevel structures was designed. This method is based on the existing model of proximity effect computation and it minimizes the computing time necessary to obtain the exposure doses.
|
259 |
Untersuchung der Auflösungsgrenzen eines Variablen Formstrahlelektronenschreibers mit Hilfe chemisch verstärkter und nicht verstärkter NegativlackeSteidel, Katja 02 September 2010 (has links)
Ziele wie eine hohe Auflösung und ein hoher Durchsatz sind bisher in der Elektronenstrahllithografie nicht gleichzeitig erreichbar; es existieren daher die Belichtungskonzepte Gaussian-Beam und Variable-Shaped-Beam (VSB), die auf Hochauflösung respektive Durchsatz optimiert sind. In dieser Arbeit wird der experimentelle Kreuzvergleich beider Belichtungskonzepte mit Hilfe chemisch verstärkter und nicht verstärkter Lacksysteme präsentiert. Als quantitativer Parameter wurde die Gesamtunschärfe eingeführt, die sich durch quadratische Addition der auflösungslimitierenden Fehlerquellen, also Coulomb-Wechselwirkungen (Strahlunschärfe), Lackprozess (Prozessunschärfe) und Proximity-Effekt (Streuunschärfe), ergibt. Für den Vergleich wurden wohldefinierte Prozesse auf 300 mm Wafern entwickelt und umfassend charakterisiert. Weitere Grundlage ist die Anpassung oder Neuentwicklung spezieller Methoden wie Kontrast- und Basedosebestimmung, Doughnut-Test, Isofokal-Dosis-Methode für Linienbreiten und Linienrauheit sowie die Bestimmung der Gesamtunschärfe unter Variation des Fokus. Es wird demonstriert, dass sich mit einer kleineren Gesamtunschärfe die Auflösung dichter Linien verbessert. Der direkte Vergleich der Gesamtunschärfen beider Belichtungskonzepte wird durch die variable Strahlunschärfe bei VSB-Schreibern erschwert. Da für die Bestimmung der Gesamtunschärfe keine Hochauflösung nötig ist, wird das Testpattern mit größeren Shots belichtet und induziert somit eine größere Gesamtunschärfe. Es wird gezeigt, dass die Prozessunschärfe den größten Anteil der Gesamtunschärfe stellt. Außerdem spielt die Streuunschärfe bei Lackdicken kleiner 100 nm und Beschleunigungsspannungen von 50 kV oder größer keine Rolle.:Titelblatt
Kurzfassung / Abstract
1 Motivation
2 Grundsätze und Fragestellungen der Elektronenstrahllithografie
2.1 Wirkprinzipien der Elektronenoptik
2.1.1 Köhlersche Beleuchtung
2.1.2 Linsenfehler
2.1.3 Raumladung, Coulomb-Wechselwirkungen und Strahlunschärfe
2.2 Proximity-Effekt
2.2.1 Streuprinzipien der Wechselwirkung Elektron-Materie
2.2.2 Strukturdefinition, Proximity-Effekt-Korrektur und Streuunschärfe
2.3 Lackeigenschaften und Lackchemie
2.3.1 Tonalität und Prozessierung
2.3.2 Kontrast und Empfindlichkeit
2.3.3 Chemisch nicht verstärkte Lacke
2.3.4 Chemisch verstärkte Lacke
2.3.5 Prozessunschärfe
2.4 Auflösung
2.4.1 Prinzip von Gaussian-Beam und Variable-Shaped Beam
2.4.2 Aufbau, Strahlengang, Intensitätsprofil und Auflösung beider Belichtungskonzepte
2.4.3 Messtechnische Bestimmung der Auflösung
2.4.4 Schlussfolgerung für die Auflösung und Definition der Gesamtunschärfe
3 Prozessentwicklung und -charakterisierung
3.1 Chemisch verstärkte Negativlacke einer Lackserie
3.1.1 Vergleich der Schichtdicken und -nonuniformitäten
3.1.2 Vergleich der Kontrastkurven und Charakteristika
3.1.3 Entwicklungseinfluss auf Kontrastkurven und Linienbreiten
3.1.4 Vergleichende Backempfindlichkeiten bezüglich PAB und PEB
3.1.5 Auswahl von Prozess und nCAR3 für weitere Experimente
3.1.6 Struktur des Lackmaterials und FTIR-Untersuchungen des nCAR3
3.2 HSQ als chemisch nicht verstärkter Lack
3.2.1 Prozessierung
3.2.2 Schichtdicken und -nonuniformitäten
3.2.3 Einfluss der Entwicklung und der Wartezeit nach dem Belacken auf Kontrastkurven und
Auflösung
3.2.4 Einfluss der Schichtdicke auf Kontrastkurven und Basedose
3.2.5 Mögliche Temperaturschritte
3.2.6 Auflösung
3.2.7 Struktur, Reaktion und grundlegende FTIR-Untersuchungen
4 Methodenentwicklung für späteren Vergleich
4.1 Kontrastbestimmung
4.2 Definition der Basedose und deren Bestimmung
4.3 Bestimmung der Modulationstransferfunktion
4.4 Doughnut-Test zur Rückstreuparameterbestimmung
4.5 Isofokal-Dosis-Methode
4.6 Erweiterte Isofokal-Dosis-Methode zur Bestimmung der Gesamtunschärfe unter Variation des Fokus
5 Experimenteller Kreuzvergleich
5.1 Prozessbedingungen für nCAR3 und HSQ
5.2 Prozessvergleich: Kontrast, Basedose, Prozessbreite
5.3 Isofokal-Dosis-Methode angewendet auf Linienbreite, Auflösung und Linienrauheit
5.4 Bestimmung der Gesamtunschärfe
5.5 Doughnut-Test für Variable-Shaped-Beam-Schreiber
5.6 Vergleich der Modulationstransferfunktionen
5.7 Auflösung isolierter und dichter Linien
5.8 Interpretation und Verknüpfung der experimentellen Ergebnisse
6 Zusammenfassung und Ausblick
Abkürzungen
Formelzeichen und Symbole
Literaturverzeichnis
Veröffentlichungen
Danksagung
Lebenslauf / Up to now, targets like high resolution and high throughput can not be achieved at the same time in electron beam lithography; therefore, the exposure concepts Gaussian-Beam and Variable-Shaped-Beam (VSB) exist, which are optimized for high resolution and throughput, respectively. In this work, the experimental cross-comparison of both exposure concepts is presented using chemically amplified and non-chemically amplified resist systems. For quantification the total blur parameter has been introduced, which is the result of the quadratic addition of the resolution limiting error sources, like Coulomb interactions (beam blur), resist process (process blur) and proximity-effect (scatter blur). For the comparison, well-defined processes have been developed on 300 mm wafers and were fully characterized. Further basis is the adaption or the new development of special methods like the determination of contrast and basedose, the doughnut-test, the isofocal-dose-method for line widths and line roughness as well as the determination of the total blur with variation of the focus. It is demonstrated, that the resolution of dense lines is improved with a smaller total blur. The direct comparison of the total blur values of both exposure concepts is complicated by the variable beam blur of VSB writers. Since high resolution is not needed for the determination of the total blur, the test pattern is exposed with larger shots on the VSB writer, which induces a larger total blur. It is shown that the process blur makes the largest fraction of the total blur. The scatter blur is irrelevant using resist thicknesses smaller than 100 nm and acceleration voltages of 50 kV or larger.:Titelblatt
Kurzfassung / Abstract
1 Motivation
2 Grundsätze und Fragestellungen der Elektronenstrahllithografie
2.1 Wirkprinzipien der Elektronenoptik
2.1.1 Köhlersche Beleuchtung
2.1.2 Linsenfehler
2.1.3 Raumladung, Coulomb-Wechselwirkungen und Strahlunschärfe
2.2 Proximity-Effekt
2.2.1 Streuprinzipien der Wechselwirkung Elektron-Materie
2.2.2 Strukturdefinition, Proximity-Effekt-Korrektur und Streuunschärfe
2.3 Lackeigenschaften und Lackchemie
2.3.1 Tonalität und Prozessierung
2.3.2 Kontrast und Empfindlichkeit
2.3.3 Chemisch nicht verstärkte Lacke
2.3.4 Chemisch verstärkte Lacke
2.3.5 Prozessunschärfe
2.4 Auflösung
2.4.1 Prinzip von Gaussian-Beam und Variable-Shaped Beam
2.4.2 Aufbau, Strahlengang, Intensitätsprofil und Auflösung beider Belichtungskonzepte
2.4.3 Messtechnische Bestimmung der Auflösung
2.4.4 Schlussfolgerung für die Auflösung und Definition der Gesamtunschärfe
3 Prozessentwicklung und -charakterisierung
3.1 Chemisch verstärkte Negativlacke einer Lackserie
3.1.1 Vergleich der Schichtdicken und -nonuniformitäten
3.1.2 Vergleich der Kontrastkurven und Charakteristika
3.1.3 Entwicklungseinfluss auf Kontrastkurven und Linienbreiten
3.1.4 Vergleichende Backempfindlichkeiten bezüglich PAB und PEB
3.1.5 Auswahl von Prozess und nCAR3 für weitere Experimente
3.1.6 Struktur des Lackmaterials und FTIR-Untersuchungen des nCAR3
3.2 HSQ als chemisch nicht verstärkter Lack
3.2.1 Prozessierung
3.2.2 Schichtdicken und -nonuniformitäten
3.2.3 Einfluss der Entwicklung und der Wartezeit nach dem Belacken auf Kontrastkurven und
Auflösung
3.2.4 Einfluss der Schichtdicke auf Kontrastkurven und Basedose
3.2.5 Mögliche Temperaturschritte
3.2.6 Auflösung
3.2.7 Struktur, Reaktion und grundlegende FTIR-Untersuchungen
4 Methodenentwicklung für späteren Vergleich
4.1 Kontrastbestimmung
4.2 Definition der Basedose und deren Bestimmung
4.3 Bestimmung der Modulationstransferfunktion
4.4 Doughnut-Test zur Rückstreuparameterbestimmung
4.5 Isofokal-Dosis-Methode
4.6 Erweiterte Isofokal-Dosis-Methode zur Bestimmung der Gesamtunschärfe unter Variation des Fokus
5 Experimenteller Kreuzvergleich
5.1 Prozessbedingungen für nCAR3 und HSQ
5.2 Prozessvergleich: Kontrast, Basedose, Prozessbreite
5.3 Isofokal-Dosis-Methode angewendet auf Linienbreite, Auflösung und Linienrauheit
5.4 Bestimmung der Gesamtunschärfe
5.5 Doughnut-Test für Variable-Shaped-Beam-Schreiber
5.6 Vergleich der Modulationstransferfunktionen
5.7 Auflösung isolierter und dichter Linien
5.8 Interpretation und Verknüpfung der experimentellen Ergebnisse
6 Zusammenfassung und Ausblick
Abkürzungen
Formelzeichen und Symbole
Literaturverzeichnis
Veröffentlichungen
Danksagung
Lebenslauf
|
260 |
The impact of knowledge capital on regional total factor productivityLeSage, James P., Fischer, Manfred M. 04 1900 (has links) (PDF)
This paper explores the contribution of knowledge capital to total factor productivity
differences among regions within a regression framework. The dependent variable is total factor
productivity, defined as output (in terms of gross value added) per unit of labour and physical
capital combined, while the explanatory variable is a patent stock measure of regional
knowledge endowments. We provide an econometric derivation of the relationship, which in the
presence of unobservable knowledge capital leads to a spatial regression model relationship. This
model form is extended to account for technological dependence between regions, which allows
us to quantify disembodied knowledge spillover impacts arising from both spatial and
technological proximity. A six-year panel of 198 NUTS-2 regions spanning the period from
1997 to 2002 was used to empirically test the model, to measure both direct and indirect effects
of knowledge capital on regional total factor productivity, and to assess the relative importance
of knowledge spillovers from spatial versus technological proximity. (authors' abstract)
|
Page generated in 0.0338 seconds