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Scintillation SE detector for ESEM
Odehnal, Adam ; Špinka, Jiří (referee) ; Jirák, Josef (advisor)
Thesis deals with theoretical knowledge about scanning electron microscopy and environmental scanning electron microscopy. It describes principle of operation, signals generated by interaction between primary electron beam and specimen and means of detection of secondary electron signal in environmental conditions using scintillation detector. Furthermore, thesis focuses on optimization of detection od secondary electrons by adjusting electrode system of scintillation detector. Computer program Simion is used for modelling signal electron trajectories for proper adjustments. Simulation were starting-point for adjusting the design of the detector. Detection efficiency of adjusted detector was determined by evaluating signal magnitude from captured images, secondary electron detection capability from voltage contrast and quality of the captured images from signal/noise ratio.
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Nozzle separation valve design for rasterization electron microscope
Hoffman, Petr ; Navrátil, Václav (referee) ; Foltýnová, Dana (advisor)
The aim of the thesis is a design and subsequent construction of a vacuum separation valve for a scanning electron microscope. The introduction describes the functions of an isolating valve. The function of the scanning electron microscope is described in the overview of the current state of knowledge. The following chapters focus on conceptual designs of the valve, their descriptions, advantages and disadvantages. Based on the comparison, the most suitable solution was selected. A force analysis of the selected variant is also performed and described. The end of the thesis contains the whole structure design and processed drawing documentation.
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Optimization of UHV SEM for nanostructure study in wide temperature range
Axman, Tomáš ; Zigo,, Juraj (referee) ; Bábor, Petr (advisor)
This diploma thesis deals with the optimization of ultra-high vacuum scanning electron microscope - UHV SEM, which is developed within the Amispec project in cooperation with BUT, Institute of Scientific Instruments of the Czech Academy of Science and Tescan Brno, s.r.o. The theoretical part deals with the description of the actual state of the developed equipment and the research of competing systems. The next part describes the optimization of the sample holder and the pallet receptor for studying nanostructures over a wide range of temperatures. Part of the optimization is the sapphire thermal diode development and experimental verification of the functionality of the designed components. This is followed by the verification of the functionality of the whole system for the transport of samples to the UHV area, deposition with effusion cell and in-situ observations.
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Thermal stability of sputtered yttrium oxide layers
Kršňák, Jiří ; Boušek, Jaroslav (referee) ; Hégr, Ondřej (advisor)
This work deals with behavior of deposited yttrium oxide thin film after heat stress. Within solution thin yttrium oxide films were deposited at silicon substrates, which were exposed to various cycles of heat stress. Tested structures were investigated before and after heat stress in term of surface topography stability with the hepl of electron microscopy.
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Detection of signal electrons in ESEM
Šváb, Martin ; Špinka, Jiří (referee) ; Jirák, Josef (advisor)
This bachelor's thesis deals with problems of environmental scanning electron microscopy and with detection of signal electrons at higher pressure in working chamber. In this thesis I will focus on comparison of detected signal level achieved under different working conditions.
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Influence of working conditions on the signal level detected by BSE detector
Bednář, Eduard ; Zimáková, Jana (referee) ; Čudek, Pavel (advisor)
This thesis deals with the evaluation of the quality of the signal level of backscattered electrons detected by the scintillation backscattered electron detector depending on the working conditions in low vacuum scanning electron microscope. The theoretical part describes the issue of environmental scanning electron microscopy, the principle of generation the signal and detection of backscattered electrons. The experimental part of the thesis is to measure the properties of the scintillation detector of backscattered electrons. A series of experiments is evaluated the influence of working conditions on the stability and function of the detector of backscattered electron.
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Nozzle separation valve design for rasterization electron microscope
Hoffman, Petr ; Navrátil, Václav (referee) ; Foltýnová, Dana (advisor)
The aim of the thesis is a design and subsequent construction of a vacuum separation valve for a scanning electron microscope. The introduction describes the functions of an isolating valve. The function of the scanning electron microscope is described in the overview of the current state of knowledge. The following chapters focus on conceptual designs of the valve, their descriptions, advantages and disadvantages. Based on the comparison, the most suitable solution was selected. A force analysis of the selected variant is also performed and described. The end of the thesis contains the whole structure design and processed drawing documentation.
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Analysis and characterisation of spirally-arranged field-emission nanostructure
Ondříšková, Martina ; Sobola, Dinara (referee) ; Knápek, Alexandr (advisor)
Katody obsahující pole emitorů s vysokým poměrem stran budí velký zájem jako elektronové zdroje pro vakuová zařízení. Ve snaze maximalizovat proud a proudovou hustotu byly navrženy hustší pole emitorů. To však vedlo k nežádoucím účinkům, jako je stínění pole, způsobené přítomností okolních emitorů v poli. Pro snížení efektu stínění, a tím pádem zvýšení proudové hustoty, bylo navrženo pole emitorů s uspořádáním inspirovaným přírodním principem fylotaxe. Takto navržená struktura mikropilířů byla vytvořena pomocí elektronové litografie a reaktivního iontového leptání. K vytvoření ultra ostrých hrotů s poloměrem v řádu desítek nanometrů na vrcholu každého mikropilíře byla použita technika leptání black siliconu. Analýza topografie vzorku byla provedena pomocí rastrovacího elektronového mikroskopu. Pro stanovení výstupní práce byla použita ultrafialová fotoelektronová spektroskopie. Pro zjištění emisních vlastností vyrobených struktur byl zkonstruován emisní mikroskop, jehož elektronové dělo bylo upraveno tak, aby vyrobená struktura sloužila jako katoda. Graf Murphy-Good byl použit k analýze dat o emisních vlastnostech, na které byl aplikován ortodoxní test pro kontrolu validity. Pro sledování fluktuací proudu bylo provedeno měření stability.
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Fabrication and characterisation of plasmonic antennas on selected thin film with aim to get enhanced absorption due to presence of strong coupling
Vodička, Martin ; Kepič, Peter (referee) ; Liška, Jiří (advisor)
Strong coupling systems offer many important applications in various fields such as photonics, chemistry, nonlinear optics and others. This Bachelor's thesis focuses on the fabrication of metal plasmonic structures suitable for the formation of strong coupling between localized surface plasmon antennas and hexagonal boron nitride (hBN) thin film phonons in the infrared region. In the case of inducing a strong coupling, an increase in absorption should occur, which makes it possible to use this system to fabricate an infrared detector, the so-called microbolometer. The thesis summarizes important findings from electromagnetic field theory, describes the formation of strong coupling from the perspective of classical physics and gives examples of systems with strong coupling. Furthermore, the formation of surface plasmon polaritons and localized surface plasmons (LSPs) is theoretically described. Plasmonic antennas, their fabrication, applications and physical properties of hBN are described. In the practical part of the thesis, fabrication of plasmonic antennas under or on hBN thin film has been realized. The fabricated samples were characterized by scanning electron microscopy and the spectral response was measured by Fourier transform infrared spectroscopy. In the spectra, the absorption of hBN at 7.3 m was confirmed and additional transmittance minima corresponding to the presence of antennas were detected. The presence of a strong coupling between the LSPs antennas and the phonons of the native SiO2 layer was probably observed. Whether there was a strong coupling between the LSPs antennas and the hBN phonons cannot be inferred from the the obtained results.
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