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The graphene structures suitable for field effect transistors
Kurfürstová, Markéta ; Bartošík, Miroslav (referee) ; Mach, Jindřich (advisor)
This bachelor’s thesis is focused on preparation of graphene structures suitable for field effect transistors. In the first section, graphene is characterized in terms of its properties and prepataion methods. The second part sums up semiconductor technology, focusing on transistors with graphene layer. Next, electron beam litography method is presented, which had been used for preparation of the structures. Finally, an experimental procedure of graphene structures manufacture is described.
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Properties study of periodic gratings prepared by electron-beam lithography
Krátký, Stanislav ; Opletal, Petr (referee) ; Matějka, Milan (advisor)
This study examines the process of the relief periodic structures creation by way of electron beam lithography. It describes how to design these structures by means of a computer and subsequently how to create them by electron beam lithograph. Moreover, this study explores the methods by which these structures are measured and evaluated. These methods are used to measure and evaulate binary periodic gratings and thanks to obtained data it can be determined the dependence of the depth of grating on its period. The study also contains measurement of diffraction efficiency on manufactured gratings and comparison of the dependence of its diffraction efficiency on the depth of grating.
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Fabrication of SiO2 by anisotropic etching of silicon
Balajka, Jan ; Kolíbal, Miroslav (referee) ; Urbánek, Michal (advisor)
The aim of the bachelor's thesis is the fabrication of silicon dioxide (SiO2) membranes on silicon (Si) substrate by anisotropic etching of silicon. Masks for anisotropic silicon etching were prepared by electron beam litography and SiO2 wet etching. Individual steps of membrane fabrication are described, including used experimental conditions. In order to optimize the fabrication process, etch rates of Si/SiO2 in several solutions were measured. Results of the measurements are included in the thesis. Fabricated membranes were characterised by optical microscopy, scanning electron microscopy and spectroscopic reflectometry. Methods used for fabrication and analysis of defined structures created by anisotropic silicon etching are briefly summarized.
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Plasmonic structures fabricated by e-beam lithography
Šimík, Marcel ; Urbánek,, Michal (referee) ; Krátký, Stanislav (advisor)
The presented study deals with the process of the formation of plasmonic structures using electron beam lithography. The main aim of this work is to create a structure published in NatureNanotechnology using PMMA resist. It has been created several variants of these structures with different exposure doses and shapes in order to determine the best option. From these variants it is concluded which one is the most effective by using optical and electron microscopy. With this information are created and evaluated large-scale exposure.
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Industrial applications of optical nanoantennas
Binková, Petra ; Édes, Zoltán (referee) ; Babocký, Jiří (advisor)
This bachelor's thesis deals with fabrication of optical nanoantennas using electron beam lithography and their industrial applications. We have designed optical components that can be used as optical security elements to prevent forgery of plastic bank notes, ID cards, credit cards etc. Designed structures were succesfully fabricated and tested.
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Plasmonically active nanostructures for optical filtering
Idesová, Beáta ; Liška, Jiří (referee) ; Rovenská, Katarína (advisor)
This bachelor’s thesis deals with optical color filters composed of plasmonically active nanostructures and studies the parameters which influence the performance of such filters. Using electron beam litography and selective reactive ion etching, plasmonic hole-like filters were prepared in alumina film on fused silica substrate. The fabricated arrays of nanostructures, acting as optical filters, varied in shape and size of the nanostructures, distances among the nanostructures and their lateral arrangement within the arrays. The influence of these factors on transmission spectra of plasmonic filters was experimentally analysed using optical spectroscopy. A majority of the observed alternations of the measured transmission spectra was consistent with the research study which is, as well, part of this thesis. The highest color filtering selectivity was observed in arrays with divided square structure shape which also exhibited decent transmittance.
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The contrast curves determination for e-beam writer with Gaussian beam
Šuľan, Dušan ; Horáček,, Miroslav (referee) ; Krátký, Stanislav (advisor)
This work deals with technological process of structures creating by using of electron beam lithography. The main focus of the work is contrast curves of PMMA resist determination for electron beam lithography system Vistec EBPG 5000+ ES. Contrast curves are determined for different developers, developing times and the depths of resist. Sensitivity and the contrast of resist are determined from these contrast curves for each resist-developer system. Sensitivity curves are applied to the proximity effect correction on real structures, specifically the periodic diffraction gratings and then they are evaluated.
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Electrostatic Deflection and Correction Systems
Badin, Viktor ; Oral, Martin (referee) ; Zlámal, Jakub (advisor)
The aim of this master's thesis is to explore and study dynamic aberration correction options in electron-beam lithography systems. For the calculations, the thesis uses the optical column of the BS600 electron-beam writer. The thesis focuses on corrections of the third order field curvature, astigmatism, and distortion aberrations of the currently used magnetic deflection system and a newly designed electrostatic deflection system. The parameters of the two deflection and correction systems were compared.
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Transport properties of single graphene domains
Vysocký, Filip ; Kormoš, Lukáš (referee) ; Procházka, Pavel (advisor)
This bachelor thesis is focused on the preparation of single graphene domains by chemical vapor deposition method, its transfer onto non-conductive substrates and subsequent fabrication of the grapehene field effect transistors. The theoretical part of the tesis deals predominantly with different procedures of graphene production. The practical part of the thesis describes the production of graphene field effect transistors by electron beam lithography and the measurement of their transport properties.
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