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Adaptive scanning based on lower resolution images
Dymáček, Michal ; Klapetek, Petr (referee) ; Pavera, Michal (advisor)
Tato diplomová práce se zabývá vývojem metody adaptivního skenování založené na obrázcích s nižším rozlišením, která má za cíl zkrátit dobu měření a otevřít tak nové možnosti metod SPM, konkrétně mikroskopie atomárních sil (AFM), pro aplikace např. v biologii a polovodičovém průmyslu. V prvním kroku navrhovaného přístupu je pořízen obrázek s nižším rozlišením, který je uměle zvětšen s využitím interpolace a dále zpracován pro tvorbu rychlostní mapy, která určuje rychlost skenování pro jednotlivé řádky druhého měření. Řádky protínající vyvýšené struktury jsou skenovány pomalu, čímž je zachována nutná přesnost, ale celková doba měření je snížena, jelikož jsou řádky obsahující pouze povrch substrátu skenovány zvýšenou rychlostí. Na základě rešeršní studie a provedených experimentů byl navržen přístup adaptivního skenování využívající skriptovací modul SPM mikroskopu LiteScope založený na programovacím jazyce Python. S využitím tohoto přístupu bylo dosaženo redukce doby měření o 30 % pro kalibrační mřížku TGQ1.
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Evaporation of thin films using intense laser light observed operando in a scanning electron microscope
Boleloucká, Eliška ; Ukropcová, Iveta (referee) ; Nováček, Zdeněk (advisor)
This work focuses on the modification of the sample surface using intense laser light. This is one of the desired features of the new generation of multifunctional SPM probes, which are under development. In the first chapter is introduced the SPM probe itself, which allows correlative measurements. Following section contains the implementation of the intense laser light into the electron microscope chamber, together with the modification made to the detection branch of the microscope. The COMSOL Multiphysics software environment is used to simulate the interaction of the laser light with the sample surface. The results of the simulations of the temperature field in the sample are then compared with the results of the direct interaction of the sample surface with the laser light in the electron microscope chamber.
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Development of a method for simultaneous measurement of cathodoluminescence and topography of nanostructures
Vacek, Martin ; Klok, Pavel (referee) ; Nováček, Zdeněk (advisor)
The bachelor thesis focuses on the combined use of SPM and SEM techniques using an optical fiber used to collect cathodoluminescence radiation. The thesis contains of a section summarising the used techniques with more detailed description of the cathodoluminescence phenomenon. Following sections describe the development of the method, including the design and construction of the probe, tuning fork and optical fibre modifications. The results show that the newly developed method is capable of providing accurate and reliable results, thus contributing to the expanded capabilities of nanostructure characterization at the Institute of Physical Engineering.
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Application of hollow core optical fibers for the production and modification of nanostructures
Dejmek, Michael ; Průša, Stanislav (referee) ; Spousta, Jiří (advisor)
This bachelor thesis deals with the development of a new generation of SPM probes, specifically the creation and modification of nanostructures in SEM. In the framework of the presented work, we describe the light guidance in standard optical fibers and the light and gas guidance through photonic crystal fibers. We also describe the methods used (electron beam induced deposition, chemical vapour deposition) for the creation of nanostructures. In the experimental part we discuss the design and subsequent testing of the setups used for the creation of nanostructures. The results show that our method is successful and thus offers a new possibility for the creation of nanostructures at the Institute of Physical Engineering, FME BUT.
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Preparation and testing of SNOM probes
Bobek, Juraj ; Pavera, Michal (referee) ; Spousta, Jiří (advisor)
The area of research that deals with surface modification and preparation of nanostructures is still very unexplored. And only a little contribution to this field is discussed in this bachelor thesis. Its goal is to manufacture and to test a probe made off hollow optical fibre that is used in Scanning Probe Microscopy. Optical fibre parameters in combination with proper and unique techniques allow the breakthrough off very interesting applications. It's worth mentioning the gas injection in the proximity of the surface of a sample (GIS) and thus its modification by use of electrons (FEBID), ions (FIBID) or laser beams.
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The Use of AFM Measurement Method in Crystalline Silicon Solar Cells Technology
Mojrová, Barbora ; Boušek, Jaroslav (referee) ; Hégr, Ondřej (advisor)
This thesis deals with the use of Atomic Force Microscopy (AFM) and Kelvin Probe Force Microscopy (KPFM) in solar cells production. Both techniques measure surface properties using interactions between surface and tip that progressively scans entire surface of the sample. Atomic force microscopy allows three dimensional imaging of surface structure. Kelvin probe force microscopy is used to measure the contact potential difference on the sample surface. There are described experimental measurements of monocrystalline and multicrystalline substrates after various etching processes using AFM. By using KPFM the contact potential difference was measured on dielectric layers PSG, SiOX, SiNX and Al2O3 and on selective emitter structures. All experiments described in this work were carried out at the Solartec Ltd. workplace and they completely correspond with the actual technology of crystalline solar cells production.
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Assemblage and testing of the device for water ozonizing and its application for silicon wafer cleaning
Ředina, Dalibor ; Mikulík, Petr (referee) ; Voborný, Stanislav (advisor)
Deionised-ozonated water, so-called DIO3 appears to be an ideal alternative for usage in semiconductor industry. The utilisation of DIO3 for removal of photoresist from silicon wafers is faster, cheaper, and more environmental-friendly compared to classical technology based on mixture of sulphuric acid with hydrogen peroxide, so-called SPM. The diploma thesis deals firstly with research into ozone and ozonated water and their possible applications. Next sections describe two prototypes of generators for DIO3, that were assembled in CSVG a.s. Testing of parameters for generators on dissolved-ozone concentration is also a part of this thesis. Moreover, thesis involves tests, that were carrier out in ON Semiconductor in Rožnov pod Radhoštěm. These tests compare efficiency of cleaning by classical technology based on SPM and DIO3 approach.
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Noise and artifact suppression in fMRI data based on multi-echo data and independent component analysis
Pospíšil, Jan ; Gajdoš, Martin (referee) ; Mikl, Michal (advisor)
The main task of this work is to design an algorithm for suppressing unwanted noise and artifacts in fMRI data using the analysis of independent components and multi-echo data. The theoretical part deals with the basic principles of magnetic resonance, including construction and image data processing. The practical part presents a pilot design of a method inspired by a professional publication in the Matlab software environment, where this design is subsequently tested on real fMRI data provided by the Laboratory of Multimodal and Functional Imaging, CEITEC MU.
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Processing of MREG MRI data
Lampert, Frederik ; Mikl, Michal (referee) ; Gajdoš, Martin (advisor)
MR-encephalography (MREG) is an innovative method of ultrafast magnetic resonance imaging. Most of the publications about this method are concerning about acquisition and reconstruction of raw data. Studies dedicated to standardization of preprocessing MREG data have not been published yet, which led to motivation of creating this bachelor thesis. The main goal of this thesis is to set an optimal way of preprocessing MREG data, which could be advised for future studies utilizing this method. The main goal of this work was divided into several subgoals, consisting of making a literary review, implementation of general method for data preprocessing and suggesting an alternative ways of data preprocessing and their implementation into MATLAB programming language. Suggested ways of data preprocessing were evaluated by created criteria, described in this work. Results of the evaluation were discussed and interpreted by graphs. Based on the results of the evaluation, an optimal way for preprocessing data was set. It consists of movement and geometric distortion correction accomplished by SPM Realign & UNWARP function, spatial normalisation to EPI MNI template and spatial smoothing by Gaussian kernel.
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Nonlinear phenomena in optical fibers
Burian, Radek ; Horváth, Tomáš (referee) ; Münster, Petr (advisor)
The subject of this thesis is to describe nonlinear phenomena in the optic fiber. The theoretical part describes a principle of transmission in optical fibers. Optics modules, fibers and their parameters are described marginally. Except nonlinear phenomena, there is also described linear phenomena such as attenuation, dispersion, scattering. In terms of nonlinear phenomena there is described second order phenomena such as Second harmonic generation (SHG), Sum and difference harmonic generation (SFG and DFG) and third order phenomena, such as Kerr effect, Third harmonic generation (THG), Four-wave mixing (FWM) and Cross phase modulation (XPM). There are also described nonlinear scattering, such as Raman´s and Brillouin´s scattering. The Four-wave mixing is simulated in the first half of the practical part. Four-wave mixing occurs in DWMD systems, where can invoke cross-talks between channels. In the second half of the practical part is measured this nonlinear phenomenon. The aim of the measurement is to understand the behaviour of the FWM and find the way how to eliminate its power. The Four-wave mixing measurement is based on the simulation. Second measurement is designed for Brillouin scattering. The conclusion from simulated and laboratory part from both measurements are compared with theoretical knowledge.
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