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Application of Graphene Membrane in Nanoelectronic Devices
Kormoš, Lukáš ; Drbohlavová, Jana (referee) ; Bartošík, Miroslav (advisor)
This diploma thesis is focused on the applications and fabrication of graphene membrane from graphene prepared by the chemical vapor deposition. Theoretical part deals with transport properties of the graphene and multiple scattering processes limiting the charge carrier mobility in this material. Included is short review of graphene membrane applications. Experimental part provides fabrication process for achieving suspended graphene device by utilizing electron beam lithography, focused ion beam, chemical etching and patterning of graphene. Graphene membrane is characterized by transport properties measurement and compared to non-suspended graphene.
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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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Fabrication of Nanostructures and Nanodevices for Nanoelectronics and Spintronics
Lišková, Zuzana ; Červenka, Jiří (referee) ; Čech, Vladimír (referee) ; Šikola, Tomáš (advisor)
The thesis deals with preparation of graphene nanostructures and their applications in the measurement of transport properties of graphene. The contacts for measurement of resistance are fabricated by electron beam lithography on graphene exfoliated flakes, CVD graphene layers and grains. Graphene is also shaped using the same method. Resistivity of the layer, concentration and mobility of charge carriers are determined by different approaches. Hysteresis appearing in dependence of resistivity on the gate voltage is discussed as well. A significant part of the work is dedicated to monitoring the response of graphene resistance to relative humidity changes and potential use of graphene as a sensor of relative humidity.
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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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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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Study of 3D modulated magnetic structures
Dočkalová, Lucie ; Staňo, Michal (referee) ; Turčan, Igor (advisor)
This bachelor’s thesis deals with an experimental preparation and static characterization of the magnetization of 3D modulated magnetic nanostructures. The aim of the thesis is to use innovative methods in nanofabrication to devise magnetic structures that exhibit properties that cannot be achieved by standard lithography methods. In the beginning, the reader is acquainted with the micromagnetism theory. Emphasis is put on a magnetic anisotropy. The preparation of the sample is described in the second part of the thesis, together with used techniques, such as electron-beam lithography (EBL) and focused electron beam induced deposition (FEBID), are stated. In the experimental part, Kerr microscopy is used for the evaluation of static magnetic responses of prepared 3D modulated magnetic structures. They are compared with static responses of planar magnetic structures. Besides other things, amplitudes of modulations are measured using an atomic force microscope (AFM), and the influence of amplitude on the induced magnetic anisotropy is evaluated. It is found out that prepared 3D modulations induced the uniaxial anisotropy field, which can influence a preferred direction of a vector of magnetization.
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Optical response of asymmetric plasmonic structures
Babocký, Jiří ; Kolařík, Vladimír (referee) ; Čechal, Jan (advisor)
This diploma thesis deals with study of resonance modes of plasmonic structures. First part provides an overview of theoretical models, which explain the resonanace modes in plasmonic structures. Next part describes technology of electron beam lithography. First section of experimental part deas with technological processes leading to an improvement of resulting structures made by electron beam lithography that is followed by lift-off process. Last part focuses on a study of reflectance spactra of plasmonic antenas and the identification of resonance modes.
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Creation of plasmonic micro- and nanostructures by electron beam lithography
Babocký, Jiří ; Dvořák, Petr (referee) ; Kvapil, Michal (advisor)
This beachelor’s thesis deals with a fabrication of plasmonic antennas using electron beam lithography. First section consists of summary of a technologies that can be used for production of metallic micro and nanostructures on silicon and glass substrate. Second section provides a description of electron beam lithography method and technologies that are used for it. Final part describes experiments, that were done and empiric model describing dependance of dimension of fabricated structures on lithographic parameters.
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