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The preparation of Grafen by method CVD
Procházka, Pavel ; Kromka,, Alexander (referee) ; Mach, Jindřich (advisor)
This diploma thesis is mainly focused on the fabrication of graphene layers on the copper foil by the Chemical Vapor Deposition (CVD). For this purpose the high-temperature chamber for the production of the graphene was completed and fully automated. The production of the high area graphene on the copper foil was experimentally achieved. The Raman microscopy and X-ray photoelectron spectroscopy measurements proved that the produced graphene is mostly a monolayer. Graphene layer was transferred on non-conductive substrate.
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Modern cutting cemented carbide tools
Štefek, Jaromír ; Kalivoda, Milan (referee) ; Píška, Miroslav (advisor)
This thesis deals with modern cutting cemented carbide tools. In the first section are stated several basic innovations already used tools for basic machining operations, which is turning, milling and drilling. It continues with analysis of single materials for production of cemented carbides, non coated as well as coated and with comparing of their properties. There are listed the basic cutting properties of the cutting tools after that. The penultimate point of the work is optimization of the basic machining operations, namely roughing and finishing, for a given application, which is in this case turning on the lamp stand. Finally, everything is summed up and evaluated in the conclusion.
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Modern cutting cemented carbide tools
Vopařil, Josef ; Humár, Anton (referee) ; Píška, Miroslav (advisor)
This thesis is focused on cutting tools made of cemented carbides. It contains analysis of cemented carbides for uncoated and coated cutting tools. It contains examples of modern tools for turning, milling and drilling. Practical part of this thesis evaluates and compares cutting properties of two types of spiral drills.
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Characterization of VTR-7000 deposition furnace
Petrová, Lenka ; Ulrych, Jan (referee) ; Semiconductor, Vlastimil Hanáček, ON (advisor)
Tato práce je zaměřena na problém nastavení CVD pece pro produkci ve výrobním závodu. Problém je, že přesná zařízení jako depoziční pece musíbýt pro produkci nastaveny až na místě, kde budou provozovány. Toho je možno docílit pomocí statistických nástrojů jako například DOE (design of experiment). Vstupní hodnoty procesu ovlivňují výstupy. Úkolem DOE je definovat, jakým způsobem. Z předchozího DOE provedeného v závodě COM1 vyplývají některá nastavení proměnných. Jiné proměnné musí být nastaveny dle předchozích zkušeností. Úkolem práce je seznámit čtenáře se základy depozice z plynné fáze a konceptem DOE. Následně je navržen vlastní experiment. Tento je vyhodnocen a výstupem práce je pak ideální nastavení reaktoru. Čtenáři bude též nepřímo představen proces DMAIC, který byl použit při samotném experimentu a vyhodnocování v ON Semiconductor, Rožnov pod Radhoštěm, CZ4 WFAB.
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Barier films based on polyparaxylylene and their properties
Horák, Jakub ; Mazánková, Věra (referee) ; Přikryl, Radek (advisor)
This diploma thesis is focused on preparation and characterization of parylene C barrier properties. The layers were prepared by chemical vapour deposition (CVD). The interest in characterization of those layers is huge mainly because of their possible use in museology for the protection of the museum archives against the corrosion. Chlorinated dimer of para-xylylene was used as a precursor. Polypropylene foils, metal sheets and silica wafers were used as tested substrates for thin film preparation. Polypropylene foils were used for oxygen transmission rate measurements, metal sheets were used for corrosion tests and silica wafers were used for Fourier transform infrared spectroscopy (FTIR), confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM) and stylus profilometry.
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Poly-para-xylylene films preparation and characterization of their properties
Menčík, Přemysl ; Salyk, Ota (referee) ; Přikryl, Radek (advisor)
Poly-p-xylylene is a basic polymer of parylene family. It was discovered in 50s of the 20th century. In practical applications, there are used several derivates. Most of them are discussed in this thesis. Poly-p-xylylene has many utility properties, like barrier, thermal and mechanical properties. It can be used for conservation and protection of electronic equipments, medical tools and devices or museum exhibits. The most important property of parylene is its low dielectric constant which enables parylene to have good insulating properties in form of very thin layer. The most common precursor used for parylene coatings by Chemical Vapor Deposition (CVD) is [2,2]paracyclophane. Special device invented for this process was described in this thesis, including every part and assembly. The main aim of this thesis was to test properties of thin parylene layers on metal samples. High degree of polymer crystallinity was confirmed by confocal laser microscopy and optical microscopy in the polarized light measurements. Problems in the conventional method of production of parylene layers were found during the measurement of thickness of layers. Purity of deposited films was determined using Infrared spectroscopy (IR). Parylene barrier properties were quantified by the measurement of Oxygen Transmission Rate through a layer deposited on the surface of PP foil. Because the research has been mainly focused on protection of museum exhibits, the corrosion resistance test is the most important. Metal samples with thin parylene film were compared to samples with conventional restoration coating. The samples with parylene protection were slowly corroded by point corrosion. In contrast to them, the samples conserved by conventional restoration method were almost destroyed by corrosion.
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Schottky solar cells with interface graphene/Si modified by gallium
Hlavička, Ivo ; Lišková, Zuzana (referee) ; Mach, Jindřich (advisor)
Main focus of this bachelor thesis is on fabrication, characterization and modification of graphene-on-silicon Schottky solar cells. By transfering CVD graphene onto silicon wafer with electrodes, a basic Schottky junction was created. The junction was then modified by annealing in UHV chamber as well as by gallium deposition. Information about power conversion efficiency of such Schottky solar cells was then obtained by IV measurement. Schottky junction itself was analyzed using X-EBIC method.
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HSS milling cutters deposited by nanocomposite coatings
Ludvík, Radek ; Kolář, Ladislav (referee) ; Jaroš, Aleš (advisor)
This bachelor thesis deals with nanocomposite coatings deposited on cutting tools of high speed steel. The paper describes the fundamentals of milling, tools for milling and their division and clamping. Gradually, there are analyzed problems of high speed steels (their classification, marking, properties and uses, chemical composition and heat treatment). Then there is described the main characteristics of coating methods (division of coatings into generations, surface preparation before the coating and PVD and CVD methods). The last part of the thesis focuses on the properties of nanocomposite materials and to companies dealing with their application to the high-speed steel.
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Study of interface graphene-on-silicon by EBIC method
Hammerová, Veronika ; Lišková, Zuzana (referee) ; Mach, Jindřich (advisor)
This bachelor thesis is dedicated to study of interface graphene-on-silicon located on solar cell with graphene layer. The interface was studied by EBIC method and Raman spectroscopy. Solar cells with graphene sheet was fabricated using electron litography, chemical etching and graphene made by CVD method. The thesis describes fabrication of solar cells with graphene layer, method EBIC measured on SEM and analysis of changes graphene-on-silicon interface caused by enlightenment electron beam by Raman spectroscopy. In theorethical part is described p-n junction and Schottky junction of solar cell, graphene and its fabrication, as well as EBIC method fundamentals.
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New generations of PVD coatings
Kantar, Filip ; Kolář, Ladislav (referee) ; Jaroš, Aleš (advisor)
Bachelor thesis deals with methods of coating, cutting tools and a new generation of coatings. In the first part are listed and described basic coating methods. The next part is aimed on coating of PVD methods. In the third part are listed basic tool materials and their characteristics. The last part is focused on new generation of coatings, their application, properties and structures.
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