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Metallic nanostructures with three-dimensional topography for plasmonics
Rovenská, Katarína ; Kvapil, Michal (referee) ; Ligmajer, Filip (advisor)
Due to high concentration of free electrons, metallic nanostructures can support plasmonic resonances. The spectral shape of plasmonic resonances may be tuned by many factors and because of it, the field of their application, given by their capability of focusing light under the diffraction limit, broadens. This thesis deals with fabrication of gold nanostructures by electron beam litography on top of a silicon substrate. The topography of the substrate is subsequentially modified by wet anistropic etching. A part of this thesis also briefly reviews methods for fabrication of nanostructures with planar or three-dimensional topography. Using the infrared spectroscopy, this thesis further analyzes the effect of size, shape, spacing of the nanostructures, and also the substrate topography on the optical response of the fabricated nanostructures. The outcomes of this thesis verify previously described tendencies of spectral relations between optical properties and named parameters in the mid-infrared region.
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Preparation of graphene nanostructures for applications
Dubnická Midlíková, Jana ; Procházka, Pavel (referee) ; Lišková, Zuzana (advisor)
The thesis deals with preparation of graphene nanostructures and their applications in the measurement of electrical transport properties of graphene. Graphene layers are prepared by mechanical exfoliation in two ways, by using adhesive tape or elastomeric film. The contacts for measurement of graphene layers resistance are fabricated by electron beam litography on exfoliated graphene flakes. Measurements of graphene transport properties take place in two environments, in air and in vacuum. Mobility and concentration of charge carriers of prepared graphene nanostructure are determined from the measured values.
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Characterization of structures fabricated by selective wet etching of silicon
Metelka, Ondřej ; Mikulík, Petr (referee) ; Šamořil, Tomáš (advisor)
The task of master’s thesis was to perform optimalization process for preparing metal etching mask by electron beam litography and subsequent selective wet ething of silicon with crystalographic orientation (100). Further characterization of etched surface and fabricated structures was performed. In particular, attention was given to the morphology demonstrated by scanning electron microscopy and study changes of the optical properties of gold plasmonic antennas due to their undercut.
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Fabrication of micro- and nanostructures by different etching methods
Těšík, Jan ; Urbánek, Michal (referee) ; Šamořil, Tomáš (advisor)
The selective etching is currently very widely used method for the preparation of micro- and nanostructures. This thesis deals with the principles of the etching methods, their applications and also the possibilities of dry and wet etching at the Institute of Physical Engineering. The experimental part is devoted to the preparation of the etching masks to ensure etching selectivity and to the preparation of pre-defined micro- and nanostructures. Important parameters were determined from the results, e.g. Si etch rate, selectivity of the masks etc. Further, the suitability of the used methods and etching masks were compared.
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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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