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Aplikace grafénové membrány v nanoelektronických zařízeních
Kormoš, Lukáš ; Drbohlavová, Jana (oponent) ; Bartošík, Miroslav (vedoucí práce)
Táto diplomová práca je zameraná na aplikácie a výrobu grafénovej membrány z grafénu vyrobeného pomocov chemickej depozície z plynnej fáze. Teoretická časť sa zaoberá transportnými vlastnosťami grafénu a viacerými rozptylovými procesmi, ktoré obmedzujú pohyblivosť nosičov náboja v tomto materiáli. Súčasťou teoretickej časti je krátka recenzia aplikácií grafénových membrán. Experimentálna časť prezentuje výrobný proces pre dosiahnutie zaveseného grafenového zariadenia s využitím elektrónové litografie, fokusovaného zväzku iónov, chemického leptania a tvarovanie grafenovej vrstvy. Grafénová membrána je charakterizovaná meraním transportných vlastností a tieto sú následne porovnané s grafénom položeným na substráte.
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The preparation and characterisation of electrical properties of graphene CVD monocrystals
Hulva, Jan ; Rezek, Bohuslav (oponent) ; Mach, Jindřich (vedoucí práce)
Chemical Vapor Deposition (CVD) of graphene is the method of graphene synthesis capable of producing predominantly single layer graphene of large area. Part of the experimental work of this thesis is focused on the deposition and analysis of single-crystalline graphene domains grown by CVD on a copper foil. These domains are analyzed by the optical microscopy, scanning electron microscopy, atomic force microscopy and Raman spectroscopy. The next part of the work was devoted to iden- tification of defects present on the Cu foil after the deposition of graphene by means of energy dispersive X-ray spectroscopy. The amount of the defects was reduced by the adjustment of the deposition system although not all types of the defects were completely removed. Electronic transport properties of deposited graphene layers were performed in the last part. The results contain measurement of graphene in vacuum with applied back gate voltage and low temperature measurement with applied magnetic field.
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Characterization of VTR-7000 deposition furnace
Petrová, Lenka ; Ulrych, Jan (oponent) ; Semiconductor, Vlastimil Hanáček, ON (vedoucí práce)
This bachelor’s thesis deals with the problem of adjusting of a CVD (chemical vapor deposition) reactor for operations in a given plant. The problem is that precise machines such as a CVD reactor have to be adjusted for function in the place, where they will be operated. This can be done by using statistical tools such as the DOE (design of experiment). There is a range of inputs that can affect the results of the deposition process. From these some will have to be selected as constants and some will become variables in the DOE. The target of this project is to introduce the reader to the topic of CVD, then, from previous DOE done on such machine in the COM1, design an experiment to adjust the machine in CZ4 WFAB for production, evaluate the acquired data and obtain the ideal setting for the reactor. The reader will be indirectly introduced also to DMAIC process since the DMAIC was used to evaluate the actual experiment in ON Semiconductor, Rožnov pod Radhoštěm, CZ4 WFAB.
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Příprava grafenových vzorků pro experimenty v UHV podmínkách
Mareček, David ; Mach, Jindřich (oponent) ; Čechal, Jan (vedoucí práce)
Tato bakalářská práce pojednává o elektrické vodivosti grafenu a přípravě grafenového polem řízeného tranzistoru. Teoretická část popisuje elektrické vlastnosti grafenu, jeho přípravu pomocí metody CVD a přenos na SiO_2. Experimentální část této práce se zabývá přípravou grafenového polem řízeného tranzistoru s velkou vzdáleností elektrod. Kapitola se věnuje návrhu držáku vzorku a přivedením kontaktů v UHV podmínkách. Poslední část popisuje naměření závislosti vodivosti grafenové vrstvy na hradlovém napětí se zřetelem na polohu Diracova bodu při úpravě vzorku v UHV podmínkách.
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Microscopic characterization of graphene material and electronic quality across neighbouring, differently oriented copper grains
Čermák, Jan ; Yamada, T. ; Ganzerová, Kristína ; Rezek, Bohuslav
We study graphene grown across the boundary of three such grains having bright, medium, and dark color in reflection. Raman micro-spectroscopy proves presence of mostly a monoor bi-layer graphene on all the grains. Yet intensity of Raman 2D band is grain-dependent: highest at the darkest grain and lowest at the brightest one. Contrary, conductive atomic force microscopy detects the highest conductivity at the brightest grain and the lowest current at the darkest grain. This is attributed to dominant electrical current path through graphene and underlying oxide thickness of which also depends on the type of copper grain. We correlate and discuss the results with view to better understanding of graphene growth and electronic properties on large area copper substrates.
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Growth of diamond thin films: a review
Kromka, Alexander ; Potocký, Štěpán ; Rezek, Bohuslav
Diamond is shown as an extraordinary material which offers promising solution for variety of fundamental studies and industrial uses. Here, growth of synthetic diamond films at low pressures (1 atm) and low temperatures (<1000°C) from carbon consisting gas mixtures is discussed. Variety of chemical vapor deposition techniques are reviewed, their advantages and disadvantages are pointed out too.
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Diamond chemical vapor deposition
Kromka, Alexander
Present paper reviews growth of diamond thin films by various chemical vapor deposition processes. Basic characteristics and common features of processes are pointed out with a respect to quality of grown films and standard process parameters. Novel and non-standard diamond syntheses techniques are briefly discussed.
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