In-plane micro-supercapacitors (MSCs), as promising power candidates for micro-devices, typically exhibit high power densities, large charge/discharge rates, and long cycling lifetimes. The high areal/volumetric capacitances, high energy/power densities, high rate capability, as well as flexibility are the main scientific pursue in recent years. Among diverse electrode materials for MSCs, coordination polymer frameworks are emerging due to the designable porous structure and tunable functionality. However, the unsatisfied electrochemical performance still hinders their practical applications. In this work, we demonstrate the first time an efficient in-situ growth approach to precisely modify the vacancy of Prussian-blue nano-thin films with pyridine by coordination reaction for high energy-density MSCs. Confirmed by the experimental results and density functional theory calculation, the vacancy modification within Prussian-blue network improved the film-forming property, hydrophilicity, and electrochemical activity of the thin films. The resultant MSCs based on pyridine-modified Prussian-blue exhibited an ultrahigh energy density of up to 12.1 mWh cm⁻³ and an ultra-low time constant (t₀) of 0.038 ms, which are the best values among the state-of-the-art in-plane MSCs. This work provides an attractive solution for structural engineering of promising active materials on molecule level toward high-performance micro-energy devices.

New concepts in assembly technology boost our daily life in an unknown way. High end semiconductor industry today deals with functional structures down to a few nanometers. ITRS roadmap predicts an ongoing decrease of the “DRAM half pitch” over the next decade. Packaging of course is not intended to realize pitches at the nanometer scale, but has to face the challenges of integrating such semiconductor devices with smallest pitch and high pin counts into systems. Advanced techniques of nondestructive evaluation (NDE) with resolutions in volume better than 1 micrometer vixen size are urgently needed for the safety and reliability of electronic systems, especially those that are used in long living applications. The development speed of integrated circuits is still very high and is not expected to decrease in the next future. The integration density of microelectronic devices is increasing, the dimensions become smaller and the number of I/O's is getting higher. The development of new types of packages must be done with respect to reliability issues. Potential damage sources must be identified and finally avoided in the new packages. In power electronics production the condition monitoring receives a lot of interest to avoid electrical shortcuts, dead solder joints and interface crac king. It is also desired to detect and characterize very small defects like transportation phenomenon or Kirkendall voids. For this purpose, imaging technologies with resolutions in the sub-micron range are required.

In der vorliegenden Arbeit wird die Entwicklung eines kinetischen Energy Harvesters vorgestellt, der auf Grundlage des elektrostatischen Wandlerprinzips aus Vibrationen elektrische Energie generiert. Für die Umsetzung wurde eine Siliziummikrostruktur entworfen, die für Arbeitsfrequenzen unter 100 Hz ausgelegt ist. Die Zahnstruktur der verwendeten Elektroden ermöglicht Spaltabstände im Submikrometerbereich und folglich große Kapazitätsänderungen, die durch die Elektrodengeometrie zusätzlich mit einer höheren Frequenz als die mechanische Bewegung stattfinden. Vergleichsweise große Leistungsausbeuten und geringe Quellimpedanzen sind dadurch erreichbar. Die geometrischen Parameter der Elektroden wurden unter Berücksichtigung der auftretenden Fertigungstoleranzen und Wechselwirkungen zueinander optimiert. Für die Ausnutzung einer ausreichend großen Inertialmasse wurde ein feinwerktechnisch hergestellter Hebelmechanismus an die Mikrostruktur angekoppelt. Über diesen wird zusätzlich ein neuer Ansatz zur Abstimmung der Eigenfrequenz des Harvesters umgesetzt. Experimentelle Untersuchungen zeigten Ausgangsleistungen im einstelligen Mikrowattbereich bei Anregungen im Zehntel m/s²-Bereich. Durch fortschreitende Optimierungen der Fertigungstechnologie sind noch deutliche Leistungssteigerungen um mindestens zwei Größenordnungen möglich. Weiterhin wird ein Energiemanagementsystem vorgestellt, welches die effiziente Übertragung der Energie auf den Verbraucher ermöglicht. / In this work the development of a kinetic energy harvester using the electrostatic conversion principle is presented. The silicon microstructure is designed to work in frequency ranges below 100Hz. Its toothed electrode structure enables gap distances in the sub micrometer range and consequently high changes of capacitance. Additionally, due to the electrode geometry the frequency of the capacitance changes is higher then the frequency of the mechanical movement. Thus high power outputs and low source impedances can be reached. The electrodes geometric parameters were optimized considering manufacturing tolerances and interactions of the parameters. To reach a sufficient inertial mass, a lever mechanism manufactured by precision engineering was connected to the microstructure. This mechanism also allows the implementation of a new method of frequency tuning. In experimental tests power outputs in the single digit microwatt range under excitations of 0.3 m/s² were reached. In accordance of further optimizations of the manufacturing technology significantly higher outputs, by at least two orders of magnitude, are possible,. Furthermore an energy management system is presented, that allows the efficient transfer of the electrical energy to the consumer.

Flera företag använder sig än idag av mjukvarusystem som är uppbyggda med äldre mjukvaruarkitektur som den monolitiska. Ett av dessa företag är Consid vars personalsystem är uppbyggt med det utdaterade ramverket klassisk ASP och där användargränssnitt samt logik kan direkt kommunicera med varandra. Detta medför begränsningar som uppstår till följd av brister i modularitet på grund av valet av mjukvaruarkitektur, vilket försvårar vidareutveckling och ändringar i ett system. Dessa begränsningar påverkar i sin tur parametrar som prestanda, skalbarhet, säkerhet, robusthet samt integrering med modernare tekniker.  I denna rapport presenteras en litteraturstudie samt en semistrukturerad intervjustudie, i syfte att undersöka vilka mjukvaruarkitekturer som är lämpliga att implementera vid en modernisering av en monolitisk mjukvaruarkitektur. Arbetet diskuterade också vilka utmaningar som kan uppstå vid en sådan modernisering och hur de hanteras på ett effektivt sätt. Ett bedömningsschema med önskvärda parametrar, med avseende på skalbarhet, prestanda, säkerhet och robusthet, togs fram för att underlätta avgörandet vid val av mjukvaruarkitektur. Utifrån detta, beslutades det att en prototyp med en REST-baserad arkitektur skulle implementeras och utvärderas.  Resultatet av prototypen, till följd av re-architecting, visade en ökad modularisering av mjukvaruarkitekturen. I jämförelse mot med det tidigare systemet har den nya prototypen ingen större påverkan på prestanda i form av responstid. Däremot bidrog prototypen till förbättrad skalbarhet när det gäller vidareutvecklingen av systemet, eftersom det förenklar införandet av ny funktionalitet. Prototypen hade också högre säkerhet genom att isolera lager ifrån varandra samt dölja underliggande detaljer i implementationen. Dessutom blev prototypen inte bara mer robust till följd av modulariseringen, men även enklare att utföra integrationstester samt destruktiva tester mot. / Several companies still use software systems that are built with older software architecture such as the monolithic one. One of these companies is Consid, whose personnel system is built with the outdated framework Classic ASP and where the user interface and logic can directly communicate with each other. This entails limitations that arise because of shortcomings in modularity due to the choice of software architecture, which complicates further development and changes in a system. These limitations in turn, affect parameters such as performance, scalability, security, robustness, and integration with modern technologies. In this work, a literature study was conducted as well as a semi-structured interview study in order to investigate which software architectures are suitable to implement when a modernization of a monolithic software architecture, is carried out. The work also discussed the challenges that may arise in a modernization of the software architecture and how they are handled efficiently. An assessment scheme with desirable parameters regarding scalability, performance, security, and robustness, was developed to facilitate the decision in the choice of software architecture. Based on this, it was decided that a prototype with a REST-based architecture would be implemented and evaluated. The result of the prototype, following re-architecting, showed an increased modularization of the software architecture. Compared to the previous system, the new prototype has no major impact on performance in terms of response time. However, the prototype contributed to better scalability in the further development of the system as it simplifies the introduction of new functionality. The prototype also had higher security by isolating layers from each other and hiding the underlying details in the implementation. In addition, the prototype not only became more robust because of the modularization, but also easier to perform destructive tests against.

The diploma thesis focuses on the topic of cultivating microgreens in nursery school. Microgreens are young plants of various species of vegetable, that are grown in soil and are harvested approximetely after ten days. The simplicity of growing microgreens makes it an appropriate activity for preeschool-age children. Besides rewarding the children with nutricious food, it brings children the oppoturnity to develop key competences and pre- literacies. The theoretical part is an information base for growing microgreens in kindergarten conditions. It describes cultivating plants in kindergarten, it deals with historicaly, legislatively and didactic point of wiew and also describe kinds of microgreens, possibilities of use and cultivation procedures suitable for kindergarten. The aim of the diploma thesis is to present the possibility of growing microgreens in nursery school with preschool children. The empirical part focuses on the design and implementation of a set of activities in which children in kindergarten grow microgreens. In addition to cultivation, other activities are also included, in which children use the topic of microgreens in individual stages of growth. The set of activities aims primarily on reaching environmental education goals and is created using a logical model. It is...

Biologiska processer hos olika organismer påverkas av ultraviolett-B-strålning (UV-B). Kunskapen om förändringar i UV-B-flödet som nått planetens yta under det geologiska tidsspann sedan flercelligt liv uppstod är dock begränsad. Följaktligen har olika biologiska proxies använts som ett sätt att försöka rekonstruera UV-B-flödet som når jordens yta. Växter reagerar på fluktuationen av UV-B genom att variera produktionen av fenolföreningar såsom parakumarsyra (pCA) och ferulinsyra, och därför kan dessa beståndsdelar användas som UV-B-proxys. UV-B-absorberande föreningar (UAC) finns i växternas yttersta skikt, den så kallade kutikulan men även i pollen och sporer, vilka oftaär välbevarade i det geologiska arkivet. Ändå är användningen av kutikula som UV-B-proxy inte lika undersökt. Därför syftar denna magisteruppsats till att analysera kemiska förändringar i fossila växters från trias – jura-gränsen (c. 200 miljoner år gamla)  och deras potential som UV-B-proxys. Eftersom de fossila löven behövde rengöras från sediment och från förkolnat mesofyll, gjordes också en analys av de kemiska förändringarna som orsakades av de olika rengöringsstegen. Icke-destruktiva tekniker, som mikro-FTIR och konfokalt Raman-mikroskop, användes för analysen. Försöken visade att analysen endast kunde utföras med mikro-FTIR på grund av den höga auto-fluorescensen hos de fossila bladen  vilketförhindrade analys med Raman. Signifikanta förändringar orsakades då Schulzes reagens användes för borttagning av mesofyllet, vilket ledde till nitrering av kutikulan. Ett mindre aggressivt och mer hållbart alternativ till denna process har visat sig vara väteperoxid, vilket orsakade mindre förändringar av den fossila kutikulans kemiska sammansättning. Dessutom upptäcktes indikation på förekomst av UAC endast i Ginkgoites regnellii, vilket indikerar att eventuell nedbrytning av dessa föreningar inträffade under diagenesen av de andra analyserade fossilerna. / Biological processes of different organisms are impacted by ultraviolet-B radiation (UV-B). However, knowledge about alterations in the UV-B flux reaching the planet’s surface during the geological past is limited. Consequently, different biological proxies have been used as an approach to attempt reconstructing the UV-B flux reaching Earth’s surface. Plants respond to the fluctuation of UV-B by varying the production of phenolic compounds such as p-coumaric acid (pCA) and ferulic acid, and therefore these constituents can be used as UV-B proxies. UV-B-absorbing compounds (UACs) can be found in the cuticle, pollen, and spores, which are all well-preserved in the geological record. Nevertheless, the use of cuticles as UV-B proxy is not as explored. Hence, this Master’s thesis aimed to analyse chemical changes in the plant cuticles from the Triassic–Jurassic boundary and their potential as UV-B proxies. Moreover, as the cuticles needed to be cleaned from rocks and isolated from coalified mesophyll, an analysis of the chemical changes caused by the cleaning steps was also done. Non-destructive techniques, as micro-FTIR and confocal Raman microscope, were used for the analysis.  Yet, the analysis could only be conducted with micro-FTIR due to auto-fluorescence of the leaves preventing success with Raman. Main changes during the cleaning steps were caused using Schulze’s reagent, which led to nitration of the cuticles. A less aggressive and more sustainable alternative to this process is shown to be hydrogen peroxide, which caused minor alteration of the fossil cuticle’s chemical composition.  Moreover, indication of the presence of UACs was detected only in Ginkgoites regnellii, indicating that possible degradation of these compounds occurred during diagenesis of the other fossils analysed.

All organizations, regardless of size, are affected by information security awareness. Information security awareness is an important component, especially for organizations in the IT industry, to be able to respond to new cyber threats but also comply with requirements and regulations for handling customer data. The purpose of the study is to improve awareness-raising measures used by Swedish micro and small companies in the IT industry to increase information security awareness among employees. The study is performed through semi-structured interviews and then analyzed using the Grounded theory-method. The study highlights the awareness measures used in the IT industry and how they are used among companies to make employees aware of information security. In addition, the companies' underlying motives for their choice of awareness measure and their perspective on adapting the measure are examined. The study's conclusions present recommendations that can be used by micro and small companies in the IT industry to improve their awareness-raising measures. The study highlights the importance of adapting training measures, but also that companies should present reality-based scenarios to employees. In addition, it is also emphasized that incentives should be used by information security officers for employees to ensure compliance. / Alla organisationer, oavsett storlek påverkas av informationssäkerhetsmedvetenhet. Medvetenhet om informationssäkerhet är en viktig komponent i synnerhet för organisationer inom IT-branschen för att kunna bemöta nya cyberhot men också efterleva krav och regleringar för hantering av kunddata. Syftet med studien är att förbättra medvetenhetshöjande åtgärder som används av svenska mikro- och småbolag inom IT-branschen för att öka informationssäkerhetsmedvetenheten bland anställda. Studien utförs genom semistrukturerade intervjuer och analyseras sedan med hjälp av Grundad teori-metoden. Studien synliggör vilka medvetenhetsåtgärder som används inom IT-branschen och hur de används bland bolagen för att göra anställda medvetna gällande informationssäkerhet. Dessutom framgår bolagens bakomliggande motiv för deras val av medvetenhetsåtgärd samt deras perspektiv på anpassning av åtgärd. Studiens slutsatser presenterar rekommendationer som kan användas av mikro- och småbolag inom IT-branschen för att förbättra deras medvetenhetshöjande åtgärder. Studien lyfter fram betydelsen av anpassning av utbildningsåtgärder, men även att bolagen bör presentera verklighetsförankrade scenarier till de anställda. Därtill framhävs även att incitament bör användas av informationssäkerhetsansvariga till anställda för att säkerställa efterlevnad.

In this contribution, a methodology for particle tracing based on computed tomography and digital image processing is presented. It enables the tracing of particles in opaque structures using laboratory X-ray microcomputed tomography (μCT) systems that are not capable of time-resolved particle tracking. Through the development, it becomes apparent that an X-ray source with a cone beam geometry and the ability to perform fast, dynamic scans is a prerequisite for generating parabolic motion artefacts. Moreover, experimental tests are used to acquire data from simple particle sedimentations as well as from self-developed filter structures based on deep bed filtration. These experiments confirm that the particle position is located at the apex of the motion artefacts. Following the data assessment, multiple options for the particle coordinate extraction are discussed, and strategies thoroughly examined. A combination of random sample consensus (RANSAC) and the least squares method proves to be the most useful for determining the particle position. Besides, the developed methodology is validated using artificially generated data in which the motion artefact parameters of size, spatial orientation, and curvature, as well as noise, are varied. Supplementary, data is analysed manually in order to draw a comparison. In addition, to the presentation and discussion of the application of the methodology, a comparison with an artificial neural network (ANN) and the advantages and disadvantages of both methods are discussed. Finally, a first comparison of an extracted particle trace with a flow simulation through the complex structure is carried out, which shows that the particle trace follows the flow.:Table of Contents List of Figures ............................................................................................................................. i List of Tables ............................................................................................................................. vi List of Formula Symbols ......................................................................................................... vii List of Abbreviations ................................................................................................................. x 1 Introduction ....................................................................................................................... 1 2 Fundamentals .................................................................................................................... 5 2.1 Methods for Particle Tracking and Tracing .............................................................. 5 2.2 Computed Tomography .......................................................................................... 10 2.2.1 Tomography Design and Functional Principle ................................................ 10 2.2.2 Data Reconstruction ......................................................................................... 15 2.3 Digital Image Processing .......................................................................................... 18 3 Material............................................................................................................................. 30 3.1 Laboratory X-ray Tomography System TomoTU ................................................... 30 3.2 Experimental Setup .................................................................................................. 33 3.3 Choice of Particles and Medium ............................................................................. 34 4 Method development ...................................................................................................... 36 4.1 Characterisation of the Motion Artefacts ............................................................... 38 4.2 Method Consideration ............................................................................................. 45 4.3 Pre-processing .......................................................................................................... 46 4.4 Combination of Random Sample Consensus and Least Squares Method.......... 48 4.5 Multiple Particle Tracing .......................................................................................... 51 4.6 Coordinate Processing ............................................................................................. 53 4.7 Method Validation .................................................................................................... 53 5 Results and Discussion .................................................................................................... 59 5.1 Evaluation experimental data ................................................................................. 59 5.2 Comparison with Computational Fluid Dynamics (CFD) ....................................... 68 5.3 Comparison of Artificial Neural Networks with the Developed Classical Digital Image Processing Approach ............................................................................................... 70 6 Summary, Conclusion and Outlook ............................................................................... 74 7 References ........................................................................................................................ 76 / Die vorliegende Arbeit stellt eine auf Computertomografie und digitaler Bildverarbeitung basierte Methodik für die Partikelverfolgung dar. Diese ermöglicht es, mittels Labor- Microcomputertomografie (μCT) Anlagen, welche nicht dazu in der Lage sind, zeitaufgelöste Partikelverfolgung zu realisieren, Partikel in opaken Strukturen zu verfolgen. Durch die Methodenentwicklung ergibt sich, dass eine Röntgenquelle mit Kegelstrahlgeometrie sowie die Durchführungsmöglichkeit von schnellen, dynamischen Scans Voraussetzungen sind, um parabelförmige Bewegungsartefakte zu erzeugen. Dafür werden durch experimentelle Untersuchungen Daten erzeugt, die sowohl von einfachen Partikelsedimentationen als auch von eigens entwickelten Filterstrukturen, die sich an der Tiefenfiltration orientieren, abgeleitet werden. Diese Experimente bestätigen, dass sich die Partikelposition am Scheitelpunkt der Bewegungsartefakte befindet. Auf Grundlage der ersten Messungen werden verschiedene Möglichkeiten für die Partikelkoordinatenbestimmung diskutiert und Ansätze kritisch betrachtet. Dabei hat sich eine Kombination aus dem Random Sample Consensus (RANSAC) Algorithmus und der Methode der kleinsten Quadrate als am sinnvollsten für die Bestimmung der Partikelposition ergeben. Zudem wird die entwickelte Methodik anhand von künstlich erzeugten Daten validiert, bei welchen die Bewegungsartefakt-Parameter Größe, Raumorientierung und Krümmung sowie Rauschen variiert werden. Zusätzlich werden auch Daten manuell ausgewertet, um einen Vergleich ziehen zu können. Neben der Präsentation und Diskussion der Anwendung der Methodik wird außerdem ein Vergleich zu künstlichen neuronalen Netzen (KNNs) und die Vor- und Nachteile beider Methoden diskutiert. Abschließend wird ein erster Vergleich einer extrahierten Partikelspur mit einer Strömungssimulation durch die komplexe Struktur durchgeführt, welche zeigt, dass die Partikelspur der Strömung folgt.:Table of Contents List of Figures ............................................................................................................................. i List of Tables ............................................................................................................................. vi List of Formula Symbols ......................................................................................................... vii List of Abbreviations ................................................................................................................. x 1 Introduction ....................................................................................................................... 1 2 Fundamentals .................................................................................................................... 5 2.1 Methods for Particle Tracking and Tracing .............................................................. 5 2.2 Computed Tomography .......................................................................................... 10 2.2.1 Tomography Design and Functional Principle ................................................ 10 2.2.2 Data Reconstruction ......................................................................................... 15 2.3 Digital Image Processing .......................................................................................... 18 3 Material............................................................................................................................. 30 3.1 Laboratory X-ray Tomography System TomoTU ................................................... 30 3.2 Experimental Setup .................................................................................................. 33 3.3 Choice of Particles and Medium ............................................................................. 34 4 Method development ...................................................................................................... 36 4.1 Characterisation of the Motion Artefacts ............................................................... 38 4.2 Method Consideration ............................................................................................. 45 4.3 Pre-processing .......................................................................................................... 46 4.4 Combination of Random Sample Consensus and Least Squares Method.......... 48 4.5 Multiple Particle Tracing .......................................................................................... 51 4.6 Coordinate Processing ............................................................................................. 53 4.7 Method Validation .................................................................................................... 53 5 Results and Discussion .................................................................................................... 59 5.1 Evaluation experimental data ................................................................................. 59 5.2 Comparison with Computational Fluid Dynamics (CFD) ....................................... 68 5.3 Comparison of Artificial Neural Networks with the Developed Classical Digital Image Processing Approach ............................................................................................... 70 6 Summary, Conclusion and Outlook ............................................................................... 74 7 References ........................................................................................................................ 76

Focusing on the problem of Drone vs. Unknown classification based on radar frequency-amplitude spectra using Deep Learning (DL), especially 1-Dimensional Convolutional Neural Networks (1D-CNNs), this thesis aims at reducing the current gap in the research related to adequate pre-processing techniques for hardware deployment. The primary challenge tackled in this work is determining a pipeline that facilitates industrial deployment while maintaining high classification metrics. After presenting a comprehensive review of existing research on radar signal classification and the application of DL techniques in this domain, the technical background of signal processing is described to provide a practical scenario where the solutions could be implemented. A thorough description of technical constraints, such as Field Programmable Gate Array (FPGA) data type requirements, follows the entire project justifying the necessity of a learning-based pre-processing technique for highly skewed distributions. The results demonstrate that data-adaptive preprocessing eases hardware deployment and maintains high classification metrics, while other techniques contribute to noise and information loss. In conclusion, this thesis contributes to the field of radar frequency-amplitude spectra classification by identifying effective methods to support efficient hardware deployment of 1D-CNNs, without sacrificing performance. This work lays the foundation for future studies in the field of DL for real-world signal processing applications. / Med fokus på problemet med klassificering av drönare kontra okänt baserat på radarfrekvens-amplitudspektra med Deep Learning (DL), särskilt 1-Dimensional Convolutional Neural Networks (1D-CNNs), syftar denna avhandling till att minska det nuvarande gapet i forskningen relaterad till adekvata förbehandlingstekniker för hårdvarudistribution. Den främsta utmaningen i detta arbete är att fastställa en pipeline som underlättar industriell driftsättning samtidigt som höga klassificeringsmått bibehålls. Efter en omfattande genomgång av befintlig forskning om klassificering av radarsignaler och tillämpningen av DL-tekniker inom detta område, beskrivs den tekniska bakgrunden för signalbehandling för att ge ett praktiskt scenario där lösningarna kan implementeras. En grundlig beskrivning av tekniska begränsningar, såsom krav på datatyper för FPGA (Field Programmable Gate Array), följer hela projektet och motiverar nödvändigheten av en inlärningsbaserad förbehandlingsteknik för mycket skeva fördelningar. Resultaten visar att dataanpassad förbehandling underlättar hårdvaruimplementering och bibehåller höga klassificeringsmått, medan andra tekniker bidrar till brus och informationsförlust. Sammanfattningsvis bidrar denna avhandling till området klassificering av radarfrekvens-amplitudspektra genom att identifiera effektiva metoder för att stödja effektiv hårdvarudistribution av 1D-CNN, utan att offra prestanda. Detta arbete lägger grunden för framtida studier inom området DL för verkliga signalbehandlingstillämpningar.

AlGaAs/GaAs- und AlGaAs/GaAs/InGaAs-Quantengraben-Strukturen mit dotiertem Kanal sowie modulationsdotierte AlGaAs/InGaAs/GaAs- Heterostrukturen auf Halbleitermaterialien mit hoher Elektronendriftgeschwindigkeit werden erfolgreich zur Herstellung von Mikro-Hall-Bauelementen eingesetzt. Mit Blick auf ihre Eignung als Magnetfeldsensoren werden die Signal-Linearität, die Sensitivität und das Rauschen bei schwachen und starken elektrischen Feldern untersucht. Auch bei höheren elektrischen Feldern von mehr als 1.8 kV/cm zeigen die Bauelemente mit dotiertem Kanal eine ausgezeichnete Linearität des Signals. Magnetische Empfindlichkeiten von bis zu 600 V/A/T werden im Konstantstrombetrieb gemessen. Unter Verwendung eines Si-δ-dotierten pseudomorphen InGaAs-Quantengrabens wird sowohl eine bessere Sensitivität als auch ein besseres Rauschverhalten erzielt als bei homogen dotiertem GaAs-Kanal. Als beste Signal-Rausch-Empfindlichkeit wird ein Wert von 138 dB/T erreicht für ein Bauelement von 10·10 µm Fläche (bei 300 K, 100 kHz Messfrequenz und 1 Hz Bandbreite). Da das elektrische Verhalten dieser Strukturen besonders durch die hohen Elektronendriftgeschwindigkeiten bestimmt wird, tritt auch bei hohen elektrischen Feldern bis zu 2.4 kV/cm keine Degradation des Bauelementes auf. Als niedrigste Nachweisgrenze für Magnetfelder wird ein Wert von 127 nT/√Hz bestimmt. Verglichen damit, zeigen die modulationsdotierten Bauelemente von 20·20 µm Größe zwar eine höhere Signal-Rausch-Empfindlichkeit von 141 dB/T bei geringen elektrischen Feldern, die sich aber bei höheren Feldstärken stark verschlechtert. Daher haben die Bauelemente mit dotiertem Kanal und pseudomorph verspanntem InGaAs-Quantengraben unter Ausnutzung hoher Elektronendriftgeschwindigkeit bei hohen elektrischen Feldern einige Vorteile gegenüber den modulationsdotierten Strukturen mit hoher Elektronenbeweglichkeit. Untersuchungen der thermischen Stabilität von Bauelementen mit modulationsdotiertem Quantengraben zeigen, dass eine dicke InGaAs-Schicht (innerhalb fixierter Gesamtdicke des GaAs/InGaAs-Kanals) erforderlich ist, um die parasitäre Parallel-Leitfähigkeit des GaAs-Kanals zu vermeiden. Unter Berücksichtigung dieser Erkenntnis und bei Verwendung eines hohen Dotierungsgrades werden ausgezeichnete Temperaturstabilitäten von 90 ppm/K im Konstantstrombetrieb und 192 ppm/K im Konstantspannungsbetrieb erzielt. Unabhängig davon zeigen optische Untersuchungen mit Photolumineszenz-Spektroskopie und Raman-Streuung einen hohen Fehlordnungsgrad in dünnen InGaAs-Quantengräben, der dagegen für dicke pseudomorphe InGaAs-Schichten vernachlässigbar ist. Daher resultiert eine dickere InGaAs-Schicht nicht nur in einer höheren absoluten magnetischen Sensitivität und besseren thermischen Stabilität, sondern auch in geringerem 1/f-Rauschen als Ergebnis von Leitfähigkeitsfluktuationen. Besondere Anstrengungen werden unternommen zum Einsatz der Rauschspektroskopie tiefer Zentren zur Untersuchung der Qualität von Halbleitervolumina bzw. -schichten. In Kombination mit den Untersuchungen der betriebsstromabhängigen Sensitivität erweist sich diese Methode als am Besten geeignet für die Optimierung von Mikro-Hall-Bauelementen. Der Einfluss der Skalierung des Bauelementes auf seine Charakteristika wie Rauschen und magnetische Empfindlichkeit wird untersucht. Sowohl die Signal-Rausch-Empfindlichkeit als auch die Grenzempfindlichkeit sind größenabhängig. Der Einfluss der Geometrie auf die Verteilung des elektrischen Feldes wird für die Form eines Griechischen Kreuzes durch numerische Rechnungen simuliert und diskutiert. Abgerundete Ecken erweisen sich als am Besten geeignet für die Herstellung hochsensitiver und rauscharmer Mikro-Hall-Bauelemente. / Doped-channel quantum well (QW) AlGaAs/GaAs and AlGaAs/GaAs/InGaAs as well as modulation-doped AlGaAs/InGaAs/GaAs heterostructures based on high electron drift velocity semiconductors are successfully applied to the fabrication of micro-Hall devices. Considering these devices as magnetic sensors, their properties were characterized in terms of signal linearity, sensitivity and noise at low and high electric fields. Even at electric fields higher than 1.8 kV/cm, the doped-channel devices exhibit an excellent signal linearity. Magnetic sensitivities up to 600 V/T/A in current drive mode are measured. The usage of a Si-δ-doped pseudomorphic InGaAs QW results in better sensitivity and noise performance than does uniformly doped GaAs. A maximal signal-to-noise sensitivity (SNS) of 138 dB/T is achieved in 10 μm square size device at 300 K, 100 kHz frequency and 1 Hz bandwidth. Because the performance in these structures is driven in part by the high electron drift velocity, it does not degrade even at high electric fields up to 2.4 kV/cm and corresponds to a lowest detection limit of 127 nT/√Hz. Comparatively, the modulation-doped devices of 20 μm square size exhibit a higher SNS of 141 dB/T at low electric fields, but degrade at higher fields. Thus, the doped-channel pseudomorphically strained InGaAs QW high-velocity devices have several advantages over modulation-doped high-mobility structures at high electric fields. Thermal stability studies of doped-channel QW devices reveal a thick InGaAs layer (within a fixed total thickness of the GaAs/InGaAs channel) necessary to avoid the parasitic parallel conductivity in GaAs channel. Using this result and a high doping level, superior temperature stabilities of 90 ppm/K in the current drive mode and 192 ppm/K in the voltage drive mode are attained. Independently, optical studies like photoluminescence and Raman scattering reveal a high degree of disorder in thin InGaAs QWs, being negligible for thick pseudomorphic InGaAs layers. Hence, a thick InGaAs layer causes not only a higher absolute magnetic sensitivity and a better thermal stability, but also lower 1/f noise being a result of conductivity fluctuations. Special effort is devoted to the application of deep level noise spectroscopy as a very sensitive probe for semiconductor bulk and layer quality. Combined with supply-current-related sensitivity studies, this method is most suitable for micro-Hall device optimization. The effect of device scaling on device characteristics like noise and absolute magnetic sensitivity is studied. Both the SNS and detection limit are shown as size-dependent. Additionally, geometry effects on the electric field distribution for Greek cross shapes are simulated by numerical calculations and discussed. Rounded corners appear as most appropriate for the fabrication of highly sensitive low-noise micro-Hall devices.