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The photoluminescence properties measurement of ultrathin films
Metelka, Ondřej ; Mach, Jindřich (referee) ; Šamořil, Tomáš (advisor)
The thesis briefly describes the principles and types of luminescence. In the first following research of study is also discussed the equipment which is applicable to photoluminescence experiments, including the arrangement. The second research focuses on the influence of the properties of gallium nitride (GaN) (ultra) thin films and other structures prepared by various ways on shape of photoluminescence spectra. The paperwork also describes the further optimization of photoluminescent apparatus used for the measurement of photoluminescence spectrum in the UV light radiation which is located at the Institute of Physical Engineering at the Technical University. The extension of measurements at low temperatures (design and construction of its own cryostat) is added. The conclusion concernes the test measurements to determine the effect of various settings of the apparatus on the resulting measured photoluminescence spectrum.
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Electron beam lithography on non-conductive substrates
Hovádková, Zuzana ; Šamořil, Tomáš (referee) ; Dvořák, Petr (advisor)
The expansion of electron beam lithography has been really fast during last years. It is mostly because its capability to create big structures with a fine resolution. This study focuses on electron beam lithography on non-conductive substrates, exactly on glass. The lithography on glass is mostly used in life sciences. Because of the transparence of the substrate and its non-toxicity it can be used for cell adhesion. In the experimental section there are shown and compared two techniques how to compensate the charge accumulated on the top of the surface.
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Development of Atomic- and Ion Beam Sources
Šamořil, Tomáš ; Lencová, Bohumila (referee) ; Mach, Jindřich (advisor)
The objective of this master thesis was to provide the optimization of an ion-atom beam source for the improvement of its properties. The improvement of the parameters increases the efficiency of the source during the deposition of gallium nitride ultrathin films (GaN) being important in microeletronics and optoelectronics. After optimization, the depositions of GaN ultrathin films on Si(111) 7x7 at lower temperatures (
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Influence of underetching of plasmonic antennas on their optical response
Novák, Martin ; Nebojsa, Alois (referee) ; Šamořil, Tomáš (advisor)
Influence optical response on underetching of plasmonic antennas is observed in this thesis. When light falls with resonant wavelength on the optical antennas, the electromagnetic field is amplified near this antennas. The resonant wavelength depends on the length of the antenna and on effective refractive index given by the ambient properties around the antenna. The contact surface with substrate (dielectric) is reduced by underetching the antenna and the effective refractive index is changed and thus the optical response of the antenna is changed.
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Application onf the Focused Ion on Electron Beam in Nanotechnologies
Šamořil, Tomáš ; Mikulík, Petr (referee) ; Jiruše, Jaroslav (referee) ; Šikola, Tomáš (advisor)
Nowadays, the systems that allow simultaneous employment of both focused electron and ion beams are very important tools in the field of micro- and nanotechnology. In addition to imaging and analysis, they can be used for lithography, which is applied for preparation of structures with required shapes and dimensions at the micrometer and nanometer scale. The first part of the thesis deals with one lithographic method – focused electron or ion beam induced deposition, for which a suitable adjustment of exposition parameters is searched and quality of deposited metal structures in terms of shape and elemental composition studied. Subsequently, attention is paid also to other types of lithographic methods (electron or ion beam lithography), which are applied in preparation of etching masks for the subsequent selective wet etching of silicon single crystals. In addition to optimization of mentioned techniques, the application of etched silicon surfaces for, e.g., selective growth of metal structures has been studied. The last part of the thesis is focused on functional properties of selected 2D or 3D structures.
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Comparison of the imaging capabilities of the transmission and scanning electron microscope
Maňka, Tadeáš ; Šamořil, Tomáš (referee) ; Zlámal, Jakub (advisor)
The aim of this work is to compare the imaging capabilities of the transmission and scanning electron microscope. The theoretical part describes the construction and the principle of each type of microscope. There is a list of the signal detectors, and the principle of imaging is described. The samples and their preparation are described. The practical part is aimed to imaging possibilities of both microscopes. A standard calibration samples were used for comparison. The advantages and disadvantages of both microscopes were discussed.
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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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2D and 3D analysis of semiconductor devices by SIMS
Vařeka, Karel ; Šamořil, Tomáš (referee) ; Bábor, Petr (advisor)
The chemical analysis of semiconductor structures using the SIMS method is the main part of this bachelor thesis. It allows the user to make a depth profiling and a creation of 2D or 3D material images. During the analysis of the chip from the TIGBT semiconductor, there is a sputtering of a heterogeneous structure in the material with different sputtering rates. It is convenient to make a cut through the material using a focused ion beam to create a profile, which grants the user to perform a tomographic measurement. This new surface enables a chemical analysis of a depth profile of semiconductor structures without the need for sputtering beam in dynamic SIMS mode. By reconstructing individual two-dimensional images, it is possible to assemble a three-dimensional pattern of the analysed sample area. Also, the preparation and removal of the lamella from the TIGBT chip were accomplished and analysed via a detector of transmission electrons.
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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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