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Tesi sul tema "Electron microscope"

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Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 28 luglio 2024

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1

Morgan, Scott Warwick. "Gaseous secondary electron detection and cascade amplification in the environmental scanning electron microscope /". Electronic version, 2005. http://adt.lib.uts.edu.au/public/adt-NTSM20060511.115302/index.html.

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2

Martin, Geoffrey Clive. "Virtual Scanning Electron Microscope : a web-based teaching and training solution for the Scanning Electron Microscope". Thesis, University of Cambridge, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.611878.

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3

Duckett, Gordon Richard. "Electron microscope studies of organic pigments". Thesis, University of Glasgow, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305588.

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4

Skoupý, Radim. "Quantitative Imaging in Scanning Electron Microscope". Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-432610.

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Abstract (sommario):

Tato práce se zabývá možnostmi kvantitativního zobrazování ve skenovacím (transmisním) elektronovém mikroskopu (S|T|EM) společně s jejich korelativní aplikací. Práce začíná popisem metody kvantitativního STEM (qSTEM), kde lze stanovenou lokální tloušťku vzorku dát do spojitosti s ozářenou dávkou, a vytvořit tak studii úbytku hmoty. Tato metoda byla použita při studiu ultratenkých řezů zalévací epoxidové pryskyřice za různých podmínek (stáří, teplota, kontrastování, čištění pomocí plazmy, pokrytí uhlíkem, proud ve svazku). V rámci této části jsou diskutovány a demonstrovány možnosti kalibračního procesu detektoru, nezbytné pozadí Monte Carlo simulací elektronového rozptylu a dosažitelná přesnost metody. Metoda je pak rozšířena pro použití detektoru zpětně odražených elektronů (BSE), kde byla postulována, vyvinuta a testována nová kalibrační technika založená na odrazu primárního svazku na elektronovém zrcadle. Testovací vzorky byly různě tenké vrstvy v tloušťkách mezi 1 až 25 nm. Použití detektoru BSE přináší možnost měřit tloušťku nejen elektronově průhledných vzorků jako v případě qSTEM, ale také tenkých vrstev na substrátech - qBSE. Obě výše uvedené metody (qSTEM a qBSE) jsou založeny na intenzitě zaznamenaného obrazu, a to přináší komplikaci, protože vyžadují správnou kalibraci detektoru, kde jen malý posun úrovně základního signálu způsobí významnou změnu výsledků. Tato nedostatečnost byla překonána v případě qSTEM použitím nejpravděpodobnějšího úhlu rozptylu (zachyceného pixelovaným STEM detektorem), namísto integrální intenzity obrazu zachycené prstencovým segmentem detektoru STEM. Výhodou této metody je její použitelnost i na data, která nebyla předem zamýšlena pro využití qSTEM, protože pro aplikaci metody nejsou potřeba žádné zvláštní předchozí kroky. Nevýhodou je omezený rozsah detekovatelných tlouštěk vzorku způsobený absencí píku v závislosti signálu na úhlu rozptylu. Obecně platí, že oblast s malou tloušťkou je neměřitelná stejně tak jako tloušťka příliš silná (použitelný rozsah je pro latex 185 - 1 000 nm; rozsah je daný geometrií detekce a velikostí pixelů). Navíc jsou v práci prezentovány korelativní aplikace konvenčních a komerčně dostupných kvantitativních technik katodoluminiscence (CL) a rentgenové energiově disperzní spektroskopie (EDX) spolu s vysokorozlišovacími obrazy vytvořenými pomocí sekundárních a prošlých elektronů.

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5

Löfgren, André. "Detection of electron vortex beams : Using a scanning transmission electron microscope". Thesis, Uppsala universitet, Materialteori, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-255330.

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Electron vortex beams (EVBs) are electron beams with a doughnut-like intensity profile, carrying orbital angular momentum due to their helical phase shift distribution. When employed in an electron microscope, they are expected to be efficient for the detection of magnetic signals. In this report I have investigated high angle annular dark field (HAADF) images obtained using EVBs. This was done for 300 K and 5K. For 5 K, I also compared HAADF images from an ordinary electron beam with HAADF images from an electron vortex beam. What was found was that EVBs produced doughnuts around the atomic columns. However, when taking the size of the electron source into account, this phenomena could no longer be observed. When comparing images from EVBs with images from ordinary electron beams, I found that the intensity of scattered electrons around atomic columns was broader for EVBs. This was persistent even after taking the source size into account.
Elektronvirvelstrålar (EVS) är elektronstrålar med en munk-liknande intensitetsprofil. Dessa bär på rörelsemängdsmoment på grund av sin fasdistribution. När de används i ett elektronmikroskop förväntas de vara effektiva för detektering av magnetiska signaler. I denna uppsats har jag undersökt high angle annular dark field (HAADF) bilder som erhållits med hjälp av EVS. Detta gjordes för 300 K och 5K. För 5 K, jämförde jag även HAADF bilder från en vanlig elektronstråle med HAADF bilder från en elektronvirvelstråle. Vad jag fann var att EVS producerade en munkformad intensitetsfördelning runt atomerna. Men när hänsyn till storleken på elektronkällan togs i beaktande kunde inte detta fenomen observeras längre. När bilder från EVS jämfördes med bilder från vanliga elektronstrålar, fann jag att intensiteten av spridda elektroner runt atomkolumnerna var bredare för EVS. Detta kunde observeras även efter att jag tagit hänsyn till elektronkällans storlek.

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6

Chen, Li. "Fabrication of electron sources for a miniature scanning electron microscope". Thesis, University of York, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313904.

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7

Johnson, Lars. "Nanoindentation in situ a Transmission Electron Microscope". Thesis, Linköping University, Department of Physics, Chemistry and Biology, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-8333.

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The technique of Nanoindentation in situ Transmission Electron Microscope has been implemented on a Philips CM20. Indentations have been performed on Si and Sapphire (α-Al2O3) cut from wafers; Cr/Sc multilayers and Ti3SiC2 thin films. Different sample geometries and preparation methods have been evaluated. Both conventional ion and Focused Ion Beam milling were used, with different ways of protecting the sample during milling. Observations were made of bending and fracture of samples, dislocation nucleation and dislocation movement. Basal slip was observed upon unloading in Sapphire. Dislocation movement constricted along the basal planes were observed in Ti3SiC2. Post indentation electron microscopy revealed kink formation in Ti3SiC2 and layer rotation and slip across layers in Cr/Sc multilayer stacks. Limitations of the technique are presented and discussed.

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8

Lyster, Martin. "Electron microscope studies of cadmium mercury telluride". Thesis, University of Oxford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238271.

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9

Dellith, Meike. "Electron microscope investigations of defects in DRAMs". Thesis, University of Oxford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334379.

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10

Christensen, K. N. "Electron microscope studies of oxygen implanted silicon". Thesis, University of Oxford, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292615.

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11

Elliott, Sarah Louise. "Dopant profiling with the scanning electron microscope". Thesis, University of Cambridge, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270885.

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12

Babich, I. M. "Short history of the scanning electron microscope". Thesis, Видавництво СумДУ, 2012. http://essuir.sumdu.edu.ua/handle/123456789/27513.

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13

Agarwal, Akshay. "A nanofabricated amplitude-division electron interferometer in a transmission electron microscope". Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/107101.

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Thesis: S.M., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2016.
"September 2016." Cataloged from PDF version of thesis.
Includes bibliographical references (pages 56-62).
Wavefront-division electron interferometry with the electron biprism has enabled many applications such as electron holography, exit-wave reconstruction, and demonstration of the Aharonov-Bohm effect. However, wavefront-division interferometry is limited by the requirement of high source coherence. Amplitude-division electron interferometers, first demonstrated by Marton and co-workers in 1954, can overcome this limitation. The implementation of these interferometers is hindered by the precise rotational and translational alignment required. This thesis develops a self-aligned, monolithic electron interferometer consisting of two 45 nm thick silicon layers separated by 20 gm and fabricated from a single crystal silicon cantilever on a transmission electron microscope grid by gallium focused ion-beam milling. Using this interferometer, beam path-separation and interference fringes of lattice periodicity and a maximum contrast of 15% in an unmodified 200 kV transmission electron microscope was demonstrated. This interferometer design can potentially be scaled to millimeter-scale and used in electron holography. It can also be applied to perform fundamental physics experiments such as interaction-free measurement with electrons, with the aim of significantly reducing the damage suffered by biological samples during high-resolution microscopy. Thus, the interferometer can serve as a proof-of-concept of the recently proposed 'Quantum Electron Microscope'.
by Akshay Agarwal.
S.M.

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14

Caldwell, N. H. M. "Knowledge-based engineering for the scanning electron microscope". Thesis, University of Cambridge, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.597224.

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The dissertation is an account of the author's research into the analysis, design, and implementations of knowledge-based (expert) systems for applications in the field of scanning electron microscopy. The specific tasks of interest have been fault diagnosis and instrument control. This research represents the first utilisation of knowledge-based techniques within electron microscopy. The dissertation begins by providing background material on the scanning electron microscope and surveying the expert systems literature with regard to critical areas of system design. The target applications and the associated research objectives are next summarised. A set of novel algorithms for improving the microscope by enhanced automatic control of fundamental instrument parameters, namely tungsten filament saturation and alignment, are presented, and the area of automatic focus algorithms is reinvestigated. Research into the design and implementation of an expert system for microscope fault diagnosis, including mechanisms for interfacing the expert system to the Internet, is discussed. This is followed by a detailed presentation of the development of a knowledge-based approach to instrument control. The next segment of this dissertation concentrates upon theoretical issues arising from the preceding work. A proposal is made to classify network-aware expert systems, and the impact of the Internet and the World Wide Web upon such systems is discussed within this context. An analysis of the work is performed to indicate how the practical portions of the research may be generalised to other tasks within scanning electron microscopy and outwith to other scientific instruments.

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15

Ali, Saleh Mahdi. "Quantitative analysis of information in electron-microscope images". Thesis, King's College London (University of London), 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.401716.

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16

McLaren, Mathew Jonathon. "Transmission electron microscope characterisation of iron-rhodium epilayers". Thesis, University of Leeds, 2014. http://etheses.whiterose.ac.uk/8281/.

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Iron-rhodium (FeRh) alloys exhibit an unusual magnetostructural transition, making them a fascinating topic of research. When the alloy is approximately equiatomic (Fe48Rh52 to Fe56Rh44) it is in a caesium chloride (CsCl) structure. At room temperature it is antiferromagnetic (AFM), making a first-order phase transition to a ferromagnetic (FM) state when heated above ~350K. There is also a 1% increase in unit lattice volume upon heating to the FM phase, as well as an increase in entropy and decrease in resistivity. The transition can be modified by doping, applied strain and applied magnetic field among other methods. Thin film FeRh has potential uses as part of a spin valve system for magnetic data storage and as a suitable choice for a memristor. The work presented here demonstrates the methods approached to preparing a variety of sputter-deposited thin film FeRh samples for characterisation in a transmission electron microscope (TEM) as well as by techniques such as X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). These include samples capped with epitaxial chromium (Cr) and tungsten (W) to raise and lower the transition temperature respectively. After cross-section or plan-view preparation using either a conventional ion polishing method or a focused ion beam, the samples were characterised using a variety of methods in the TEM. Initial characterisation has examined the crystal structure, layer thickness and interfacial roughness of these films, confirming results from bulk X-ray measurements. It has been found that FIB-prepared samples do not exhibit the phase transition whereas ion polished samples are unaffected. Compositional analysis of the interface FeRh makes with a magnesium oxide (MgO) substrate finds a change in iron-to-rhodium ratio while characterising the FeRh/cap interface finds significant Fe diffusion into Cr-capped samples with no interdiffusion seen in identical W-capped FeRh films. Analysis of the transition dynamics observing changes in strain and ferromagnetic domains via heating experiments have confirmed the nucleation and growth of the phase change at the interfaces. Finally, there is some evidence to suggest that a martensitic change is occurring in FeRh through the transition. The presence of twins in the FeRh as well as extra ordering spots in a FIB-prepared cross-section allude to a more complex transition than previously thought.

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17

Rosolen, Grahame Craig. "The development of a combined scanning electron microscope and scanning tunnelling microscope for nanotechnology". Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241061.

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18

Yu, Enhua. "Crossed and uncrossed retinal fibres in normal and monocular hamsters : light and electron microscopic studies /". [Hong Kong : University of Hong Kong], 1990. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13014316.

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19

Marturi, Naresh. "Vison and visual servoing for nanomanipulation and nanocharacterization using scanning electron microscope". Thesis, Besançon, 2013. http://www.theses.fr/2013BESA2014/document.

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Avec les dernières avancées en matière de nanotechnologies, il est devenu possible de concevoir, avec une grande efficacité, de nouveaux dispositifs et systèmes nanométriques. Il en résulte la nécessité de développer des méthodes de pointe fiables pour la nano manipulation et la nano caractérisation. La d´étection directe par l’homme n’ étant pas une option envisageable à cette échelle, les tâches sont habituellement effectuées par un opérateur humain expert `a l’aide de microscope électronique à balayage équipé de dispositifs micro nano robotiques. Toutefois, en raison de l’absence de méthodes efficaces, ces tâches sont toujours difficiles et souvent fastidieuses à réaliser. Grâce à ce travail, nous montrons que ce problème peut être résolu efficacement jusqu’ à une certaine mesure en utilisant les informations extraites des images. Le travail porte sur l’utilisation des images électroniques pour développer des méthodes automatiques fiables permettant d’effectuer des tâches de nano manipulation et nano caractérisation précises et efficaces. En premier lieu, puisque l’imagerie électronique à balayage est affectée par les instabilités de la colonne électronique, des méthodes fonctionnant en temps réel pour surveiller la qualité des images et compenser leur distorsion dynamique ont été développées. Ensuite des lois d’asservissement visuel ont été développées pour résoudre deux problèmes. La mise au point automatique utilisant l’asservissement visuel, développée, assure une netteté constante tout au long des processus. Elle a permis d’estimer la profondeur inter-objet, habituellement très difficile à calculer dans un microscope électronique à balayage. Deux schémas d’asservissement visuel ont été développés pour le problème du nano positionnement dans un microscope électronique. Ils sont fondés sur l’utilisation directe des intensités des pixels et l’information spectrale, respectivement. Les précisions obtenues par les deux méthodes dans diff érentes conditions expérimentales ont été satisfaisantes. Le travail réalisé ouvre la voie à la réalisation d’applications précises et fiables telles que l’analyse topographique,le sondage de nanostructures ou l’extraction d’ échantillons pour microscope électronique en transmission
With the latest advances in nanotechnology, it became possible to design novel nanoscale devicesand systems with increasing efficiency. The consequence of this fact is an increase in the need for developing reliable and cutting edge processes for nanomanipulation and nanocharacterization. Since the human direct sensing is not a feasible option at this particular scale, the tasks are usually performedby an expert human operator using a scanning electron microscope (SEM) equipped withmicro-nanorobotic devices. However, due to the lack of effective processes, these tasks are always challenging and often tiresome to perform. Through this work we show that, this problem can be tackle deffectively up to an extent using the microscopic vision information. It is concerned about using the SEM vision to develop reliable automated methods in order to perform accurate and efficient nanomanipulation and nano characterization. Since, SEM imaging is affected by the non-linearities and instabilities present in the electron column, real time methods to monitor the imaging quality and to compensate the time varying distortion were developed. Later, these images were used in the development of visual servoing control laws. The developed visual servoing-based autofocusing method ensures a constant focus throughout the process and was used for estimating the inter-object depth that is highly challenging to compute using a SEM. Two visual servoing schemes were developed toperform accurate nanopositioning using a nanorobotic station positioned inside SEM. They are basedon the direct use of global pixel intensities and Fourier spectral information respectively. The positioning accuracies achieved by both the methods at different experimental conditions were satisfactory.The achieved results facilitate in developing accurate and reliable applications such as topographic analysis, nanoprobing and sample lift-out using SEM

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20

Tanaka, H., T. Kojima, H. Tsuruta, J. Chen, T. Tanji e M. Ichihashi. "Development of a Real-Time Stereo Transmission Electron Microscope". Cambridge University Press, 2005. http://hdl.handle.net/2237/10297.

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21

Meaden, Graham M. "Cathodoluminescence studies of diamond in the scanning electron microscope". Thesis, University of Bristol, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357826.

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22

Farley, A. N. "An environmental control stage for the scanning electron microscope". Thesis, University of Bristol, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379674.

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23

Vaughn, Joel M. "Manipulation Of Nanoscale Objects in the Transmission Electron Microscope". Ohio University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1191525305.

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24

Gaudenzi, de faria Marcelo. "Robust control for manipulation inside a scanning electron microscope". Thesis, Besançon, 2016. http://www.theses.fr/2016BESA2068/document.

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Cette thèse étudie le problème de nano-positionnement à l'intérieur d'un microscope électronique à balayage (MEB). Pour obtenir des informations de position avec rapidité et précision, une installation dédiée composée d’un vibromètre placé à l'intérieur du MEB a été mise en œuvre. Cette approche diffère de méthodes basées sur le traitement d'images, car elle permet de saisir des données en temps réel sur le comportement dynamique des structures étudiées. Dans une première étude, les perturbations mécaniques agissant à l'intérieur de la chambre à vide du microscope ont été caractérisées et leurs sources ont été identifiées. Cela a démontré comment les vibrations mécaniques externes et les bruits acoustiques peuvent influer largement sur les composants à l'intérieur du MEB par couplage mécanique, limitant ainsi la précision des manipulateurs. Dans un deuxième temps, une micro-pince du commerce a été étudiée. Une différence entre ses comportements dans l'air et dans le vide a été mise en évidence, ce qui a permis d'obtenir deux modèles dynamiques pour cet organe terminal, un pour chaque environnement. Deux lois de commande ont été proposées (commande H-infini et commande basée sur un observateur d'état étendu), afin d'obtenir en temps réel un positionnement précis dans le vide, et d'atténuer les effets des perturbations mécaniques externes. Les résultats ont été validés en simulation et expérimentalement
This work studies the nano-positioning problem inside the scanning electron microscope (SEM). To acquire fast and accurate positional information, a dedicated setup was implemented consisting of a vibrometer placed inside the SEM. This approach differs from methods based on image processing, as it allows to capture real-time data on the dynamic behavior of structures. In a first study, the mechanical disturbances acting inside the microscope’s vacuum chamber were characterized and its sources were identified. This demonstrated how external mechanical vibrations and acoustic noises can largely influence the components inside the SEM through mechanical coupling, limiting the effective positioning precision of manipulators. Next, a commercial micro-gripper was studied, both in air and in vacuum, and the differences between its response were highlighted. This allowed to obtain two dynamic models for this end-effector, one for each environment. Two control laws were proposed (H-infinity control and Extended State Observer based control) for the system, to obtain a real-time, precise positioning in the vacuum environment and to attenuate the effects of the external mechanical disturbances. Results were demonstrated through simulation and experimental validation

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25

Mattiazzo, Serena. "Performances of the Ion Electron Emission Microscope at SIRAD". Doctoral thesis, Università degli studi di Padova, 2008. http://hdl.handle.net/11577/3425031.

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When an energetic ion strikes a microelectronic device it induces current transients that may lead to a variety of undesirable Single Event Effects (SEE). An important part of the activity of the SIRAD heavy ion facility at the 15 MV Tandem accelerator of the INFN Laboratories of Legnaro (Italy) concerns SEE studies of microelectronic devices destined for radiation hostile environments. An Ion Electron Emission Microscope (IEEM) is working at the SIRAD facility. In the IEEM technique, a broad ion beam irradiates a device under test (DUT) and the secondary electrons emitted by the target surface by each ion impact are collected and focused by a commercial electron emission microscope onto a fast electron detector. The spatial (x and y coordinates) and the temporal information of the ion impacts are then correlated to the SEE induced in the device under test and a SEE sensitivity map is obtained. An IEEM can achieve resolutions better than 1um, comparable to the ones achieved by nuclear microprobes techniques where the DUT is systematically scanned with micrometric precision with a microfocused beam. For a heavy ion microbeam to work one must meet severe requirements in terms of beam monochromaticity and stability. The IEEM poses no such requests. In this thesis we describe in detail the IEEM apparatus working at SIRAD facility and the performed experiments, with an initial discussion on the physical aspects involved in radiation hardness testing.

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26

Bélisle, Jonathan. "Design and assembly of a multimodal nonlinear laser scanning microscope". Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=100765.

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The objective of this thesis is to present the fabrication of a multiphoton microscope and the underlying theory responsible for its proper functioning. A basic introduction to nonlinear optics will give the necessary knowledge to the reader to understand the optical effects involved. Femtosecond laser pulses will be presented and characterized. Each part of the microscope, their integration and the design of the microscope will be discussed. The basic concepts of laser scanning microscopy are also required to explain the design of the scanning optics. Fast scanning problems and their solutions are also briefly viewed. As a working proof, the first images taken with the microscope will be presented. Fluorescent beads, rat tail tendon, gold nanoparticles and pollen grain images using various nonlinear effects will be shown and discussed.

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27

Gass, Mhairi Hope. "Low-loss electron energy loss spectroscopy in a scanning transmission electron microscope of GaInNAs". Thesis, University of Liverpool, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.415656.

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Chang, Michael Ming Yuen. "A computer-controlled system in transmission electron microscopy". Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292941.

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29

Somodi, Philippa Katherine. "Interpretation of electron holograms of doped semiconductors and phase retrieval in the transmission electron microscope". Thesis, University of Cambridge, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.613846.

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30

Hurm, Christian. "Towards an unambiguous electron magnetic chiral dichroism (EMCD) measurement in a transmission electron microscope (TEM)". Berlin Logos-Verl, 2008. http://d-nb.info/992155444/04.

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31

Staniewicz, Lech Thomas Leif. "Transmission-mode imaging in the environmental scanning electron microscope (ESEM". Thesis, University of Cambridge, 2012. https://www.repository.cam.ac.uk/handle/1810/242281.

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Electron microscopy was first conducted in the 1930s with the advent of theTEM and later the STEM. In 1969, the first commercial SEM was released,with the possibility of retrofitting it to behave like a STEM following soonafterwards. In 1979, Danilatos and Robinson advanced electron microscopyby creating a new type of SEM which allowed a controlled quantity of gasinto the sample chamber, termed ESEM. The most recent evolution in thisline was the combination of ESEM and STEM in 2005, a procedure termedWet STEM.The focus of this work is on investigating applications of this new technique,along with the contrast mechanisms involved in forming an image. Tothat end, a wide variety of samples will be imaged. Clay and paint suspensions(colloids) are used to test Wet STEM’s capacity to image submergedobjects, as well as thin objects which are stacked together. Diblock copolymerfilms are used to test Wet STEM’s ability to distinguish chemically similarmaterials without staining, the physical effects of heavy metal staining andto demonstrate the necessity of gas for the purpose of charge neutralisation. Single cell biological samples are also investigated. Internal contrast inmammalian cells is visible without recourse to staining, but chemical fixationis required despite maintaining a high relative humidity. Bacteria are moreresilient and as such are easier to image than animal cells, requiring no priortreatment. When exposed to low relative humidity, bacteria are found tocollapse. The collapse pattern is observed to differ between wild-type andcytoskeletal-deficient bacteria of the same species and strain, so it is likelythat dehydration-induced collapse offers information about the position andshape of the bacterial cytoskeleton.

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32

Murphy, Michael James. "Low-dimensional electron systems fabricated with an atomic force microscope". Thesis, University of Cambridge, 2007. https://www.repository.cam.ac.uk/handle/1810/265511.

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Over the past quarter-century, there has been intensive research into electron transport in low dimensional systems, especially those fabricated in semiconductor material. This research has added to our understanding of electrical transport properties outside of the macroscopic regime, and allowed exploration of potential device designs and fabrication methods. To define devices on micron and nanometer length scales, powerful lithographic techniques such as photolithography and electron-beam lithography have been widely employed to pattern semiconductor material. A newer technique is exploited in this research, where an atomic force microscope (AFM) performs local anodic oxidation on the surface of a shallow GaAs/ AlGaAs heterostructure. At cryogenic temperatures the resulting oxide lines define in-plane electrostatic gates of submicron size, and one-dimensional ballistic channels exhibiting quantized conduction. These techniques are also used to fabricate T-shaped quantum mechanical transistors. The conductance through these devices can be modulated by adjusting the voltage on a nearby in-plane gate, which changes the geometry of the transistor. This in turn shifts the energy of a bound electron state within the channel, causing reflection of the conduction electrons when this state is brought into resonance with the channel. For optimum operation, this device requires a hard-wall potential profile, which is a benefit of the AFM local anodic oxidation technique. The AFM oxidation technique is also used to pattern wafers of GaAs which are later cleaned and regrown in a molecular beam epitaxy system. GaAs and InAs are deposited on top of the patterned semiconductor material; the InAs self-assembles into quantum dots with zero-dimensional electron and hole states. These quantum dots, if buried under subsequent GaAs growth, are optically active and potentially useful in a wide variety of optoelectronic devices. The presence of the oxide patterns is shown to locally vary the dot density, and by careful calibration of oxide lithography and growth parameters, site selection of single dots or small populations of InAs quantum dots can be achieved.

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33

Gold, Daniel Patrick. "Transmission electron microscope studies of emitters of silicon bipolar transistors". Thesis, University of Oxford, 1989. http://ora.ox.ac.uk/objects/uuid:ec5f58c3-ced6-44fe-8f1f-d042cdb7b7b7.

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Transmission Electron Microscope (TEM) studies have been carried out of emitter regions in polysilicon contacted emitter bipolar transistors. The preparation of suitable TEM thin foils is described. In addition a technique is developed for the observation and quant jtative interpretation of the break-up of the interfacial oxide layers observed in these samples. The effect of annealing the samples prior to emitter dopant implantation (pre-annealing) is investigated for phosphorus and arsenic doped samples, implanted into a polysilicon layer 0.4μm thick, with a dose of 1x10¹⁶cm². Two wafer pre-cleans have been used prior to polysilicon deposition to produce a thin oxide (0-8Å) and a thicker oxide (14Å). In the presence of the thinner oxide, the phosphorus doped samples enhance epitaxial regrowth of the polysilicon layer compared with the arsenic doped or undoped samples. In the presence of the thicker oxide, no difference is observed between the samples. A mechanism is proposed to explain this. The mechanisms controlling the gain of a phosphorus doped device are investigated and a model proposed to explain the observed electrical characteristics. It is concluded that there are two mechanisms responsible for the observed supression of hole current. Firstly tunnelling through the interfacial oxide and secondly some blocking effect of the interface. Carrier transport in the polysilicon is not believed to contribute to this supression. A dopant sensitive etch has been applied to TEM thin foils containing fully processed emitters in state-of-the-art devices. The shape of the emitter dopant distribution is revealed in such devices for the first time, and a 2-D profile is obtained from the emitter. It is shown that reduction in the emitter depth to 8OOÅ or less does not alter the emitter dopant geometry. The technique is demonstrated to be capable of resolving spatial separations of dopant iso-concentration contours of 100Å or less.

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34

Ravichandran, M. V. "Electron microscope investigation of SiC-whisker reinforced-oxide ceramic composites". Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239253.

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35

Kazemian, Payam. "Progress towards quantitative dopant profiling with the scanning electron microscope". Thesis, University of Cambridge, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.613999.

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36

Pratt, Neil Victor. "Luminescence and scanning electron microscope studies of III-V semiconductors". Thesis, Imperial College London, 1988. http://hdl.handle.net/10044/1/47222.

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37

于恩華 e Enhua Yu. "Crossed and uncrossed retinal fibres in normal and monocular hamsters: light and electron microscopic studies". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1990. http://hub.hku.hk/bib/B31232449.

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38

Sasaki, Katsuhiro, e Hiroyasu Saka. "A simple method of the electric/magnetic field observation by a conventional transmission electron microscope". Trans Tech Publications Inc, 2005. http://hdl.handle.net/2237/5299.

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39

Arai, Shigeo, Shunsuke Muto, Takayoshi Tanji, Katuhiro Sasaki, Yahachi Saito, Michiko Kusunoki, Jiro Usukura e Nobuo Tanaka. "Development of an environmental high-voltage electron microscope for reaction science". Oxford University Press, 2013. http://hdl.handle.net/2237/20833.

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40

Buggy, T. W. "Theoretical and experimental studies using a prototype scanning transmission electron microscope". Thesis, University of Glasgow, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375453.

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41

Reid, Stephen Alastair. "A study of human skeletal maturation using the scanning electron microscope". Thesis, University College London (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288391.

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42

Jackson, Michael David. "Scanning tunnelling microscope and electron spectroscopy studies of selected GaAs systems". Thesis, University of Liverpool, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338676.

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43

Kenny, Peter Gerard. "The acquisition and analysis of multi-spectral analytical electron microscope images". Thesis, University of York, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.276346.

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44

Rogers, Peter John. "Backscatter Electron Microscope, palynofacies and geochemical analysis of Mesozoic black shales". Thesis, University of Southampton, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296422.

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45

Chuah, Joon Huang. "A multi-pixel CMOS photon detector for the scanning electron microscope". Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608077.

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46

Antypas, Ioanna. "Theoretical approaches to magnetic induction mapping in the transmission electron microscope". Thesis, University of Cambridge, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.611855.

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47

Zaggout, Fatima Nouh. "Quantification of SE dopant contrast in low voltage scanning electron microscope". Thesis, University of York, 2007. http://etheses.whiterose.ac.uk/11013/.

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48

Nye, Philip. "Computer instrumentation for voltage contrast measurement in the scanning electron microscope". Thesis, University of Edinburgh, 1990. http://hdl.handle.net/1842/15545.

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The scanning electron microscope is widely used in industry as a tool in both development and production stages of integrated circuit manufacture, firstly for very high magnification topographical inspection of circuits and secondly for various diagnostic techniques in which the electron beam interacts in some way with the circuit. The most used of these techniques is voltage contrast, in which the scanning electron microscope is used to measure voltages and waveforms within the operating circuit. There are an increasing number of systems available for making voltage contrast measurements. This thesis describes the designing, building, interconnecting and operating of instrumentation to improve the speed and accuracy and above all the usability of a computer based voltage contrast scanning electron microscope. A fast and efficient technique was developed for making accurate quantitative measurements on ICs which avoids the problems of drift due to contamination and charging which usually hamper voltage contrast instruments in real situations. Studies of the mechanisms of oxide charging and its effects on readings are made. Finally a scheme for integration of these methods into a fully computerised scanning electron microscope is proposed.

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49

Worlock, Stephen. "A model of VLSI specimen charging in the scanning electron microscope". Thesis, University of Edinburgh, 1992. http://hdl.handle.net/1842/14704.

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When VLSI devices are viewed using a Scanning Electron Microscope (SEM) with a low energy (1keV) primary beam, exposed dielectric surfaces can undergo charging. Such charging can have an adverse effect on voltage contrast testing of the device. The aim of this thesis is to improve understanding of charging behaviour. By adopting common VLSI materials and typical voltage contast SEM configurations, it makes a qualitative study of the factors that influence VLSI specimen charging. A model of specimen charging, based on the study, is then formulated and assessed.

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50

Cornille, Olivier. "Accurate 3D shape and displacement measurement using a scanning electron microscope". Toulouse, INSA, 2005. http://www.theses.fr/2005ISAT0021.

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Avec le développement actuel des nano-technologies, la demande en matière d'étude du comportement des matériaux à des échelles micro ou nanoscopique ne cesse d'augmenter. Pour la mesure de forme ou de déformations tridimensionnelles à ces échelles de grandeur, l'acquisition d'images à partir d'un Microscope électronique à Balayage (MEB) couplée à l'analyse par corrélation d'images numériques s'est avérée une technique intéressante. Cependant, un MEB est un outil conçu essentiellement pour de la visualisation et son utilisation pour des mesures tridimensionnelles précises pose un certain nombre de difficultés comme par exemple le calibrage du système et la correction des fortes distorsions (spatiales et temporelles) présentes dans les images. De plus, le MEB ne possède qu'un seul capteur et les informations tridimensionnelles souhaitées ne peuvent pas être obtenues par une approche classique de type stéréovision. Cependant, l'échantillon à analyser étant monté sur un support orientable, des images peuvent être acquises sous différents points de vue, ce qui permet une reconstruction tridimensionnelle en utilisant le principe de vidéogrammétrie pour retrouver à partir des seules images les mouvements inconnus du porte-échantillon. La thèse met l'accent sur la nouvelle technique de calibrage et de correction des distorsions développée car c'est une contribution majeure pour la précision de la mesure de forme et de déformations 3D aux échelles de grandeur étudiées. Elle prouve que, contrairement aux travaux précédents, la prise en compte de la dérive temporelle et des distorsions spatiales d'images est indispensable pour obtenir une précision de mesure suffisante. Les principes permettant la mesure de forme par vidéogrammétrie et le calcul de déformations 2D et 3D sont aussi présentés en détails. Enfin, et dans le but de valider nos travaux et démontrer en particulier la précision de mesure obtenue, des résultats expérimentaux issus de différentes applications sont présentés
With the current development of nano-technology, there exists an increasing demand for three-dimensional shape and deformation measurements at this reduced-length scale in the field of materials research. Images acquired by Scanning Electron Microscope (SEM) systems coupled with analysis by Digital Image Correlation (DIC) is an interesting combination for development of a high magnification measurement system. However, a SEM is designed for visualization, not for metrological studies, and the application of DIC to the micro- or nano-scale with such a system faces the challenges of calibrating the imaging system and correcting the spatially-varying and time-varying distortions in order to obtain accurate measurements. Moreover, the SEM provides only a single sensor and recovering 3D information is not possible with the classical stereo-vision approach. But the specimen being mounted on the mobile SEM stage, images can be acquired from multiple viewpoints and 3D reconstruction is possible using the principle of videogrammetry for recovering the unknown rigid-body motions undergone by the specimen. The dissertation emphasizes the new calibration methodology that has been developed because it is a major contribution for the accuracy of 3D shape and deformation measurements at reduced-length scale. It proves that, unlike previous works, image drift and distortion must be taken into account if accurate measurements are to be made with such a system. Necessary background and required theoretical knowledge for the 3D shape measurement using videogrammetry and for in-plane and out-of-plane deformation measurement are presented in details as well. In order to validate our work and demonstrate in particular the obtained measurement accuracy, experimental results resulting from different applications are presented throughout the different chapters. At last, a software gathering different computer vision applications has been developed

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