|
|
Growth of metastable fcc Fe thin films on Cu/Si(100) substrates
Horký, Michal ; Cháb, Vladimír (referee) ; Urbánek, Michal (advisor)
This diploma thesis deals with the preparation of epitaxially grown metastable paramagnetic Fe films alloyed by Ni on Cu/Si(100) substrates at RT. Molecular beam epitaxy of Cu(100) buffer layer was performed on H-Si(100) native SiO2 free samples treated by etching in HF or thermal treatment. The epitaxially grown Cu layers with thickness ranging from 50 up to 130 nm serves as suitable substrate for the deposition of 44-ML-thick paramagnetic Fe78Ni22. The film growth was taking place in CO atmosphere and as well as Ni it led to paramagnetic film stabilization. The structural and magnetic ion-beam-induced transformation of desired Fe-Ni structure was performed and propeties of irradiated films were characterized afterwards by MOKE. Then some specific patterns on Si(100) by e-beam litography were fabricated and they served as suitable matrix for Cu(100) buffer layer and paramagnetic Fe. Prepared Si(100), globally and locally deposited metal films were examined by LEED, XPS, AFM, AES, SEM a STM. The recorded results showed the possibility of paramagnetic films preparation on H-Si(100) where it was possible to make ferromagnetic patterns on paramagnetic background by irradiation of specific ion dose.
|
|
|
Microdefects in Czochralski Silicon
Válek, Lukáš ; Fejfar, Antonín (referee) ; Mikulík, Petr (referee) ; Spousta, Jiří (advisor)
Disertační práce se zabývá studiem defektů v monokrystalech Czochralskiho křemíku legovaných bórem. Práce studuje vznik kruhových obrazců vrstevných chyb pozorovaných na povrchu křemíkových desek po oxidaci. Hlavním cílem práce je objasnit mechanismy vzniku pozorovaného rozložení vrstevných chyb na studovaných deskách a vyvinout metody pro řízení tohoto jevu. Na základě experimentálních analýz a rozborů obecných mechanismů vzniku defektů jsou objasňovány vazby mezi vznikem defektů různého typu. Tyto jsou pak diskutovány v souvislosti s parametry krystalu i procesu jeho růstu. Takto sestavený model je využit pro vývoj procesu růstu krystalů, kterým je potlačen nadměrný vznik defektů ve studovaných deskách. Za účelem studia defektů jsou zaváděny a vyvíjeny nové analytické metody. Disertační práce byla vytvořena za podpory ON Semiconductor Czech Republic, Rožnov pod Radhoštěm.
|
|
|
Characteristic of photovoltaic system
Pokorný, Marek ; Dolenský, Jan (referee) ; Vaněk, Jiří (advisor)
The aim of this work is informed first about photovoltaics universally, works to inform the photovoltaic panels and complete plants. The work also includes instructions on how to implement PVP in accordance with law. Another part is the rough draft of the photovoltaic power 30 kWp, which can be placed on the house, computation and calculation of investment and them profitable investments to time. Design is made in two separate forms of the Fronius Solar and Sunny Design, their outputs are compared. The practical part of this work cooperates with the company SOLARTEC Ltd. for experimental measurements of the photovoltaic system and develop a methodology for setting the properties of real solar systems in operation from the measured data then stored in a database. These data further evaluate and compare the similar operating conditions. This data will show as the course of production of electricity during the typical day in percentage terms, depending on the incident irradiance, cell temperature, angle of incident radiation, etc. We can compare what it looks like an ideal day in terms of production of photovoltaic power, with the other days. Further are in work mentioned histograms achievement panel behind classical day and behind all - time investigation.
|
|
| |
|
|
Selective growth of metallic materials.
Šimíková, Michaela ; Schneeweiss, Oldřich (referee) ; Čechal, Jan (advisor)
The diploma thesis deals with selective growth of cobalt thin films on lattices created by focused ion beam on Si(111) substrates with thin film of silicon dioxide. Further, the growth and morphology of iron thin films growing on Si/SiO2 substrate without modification was studied. In the last part, thin film of a-C:H, influence of preparation parameters on their growth and ratio of sp2 and sp3 bonds, was investigated. For analysis of those films XPS, AFM, and SEM metods were used.
|
|
|
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.
|
|
|
Detection and analysis of crystal defects in Si wafer for electronics
Páleníček, Michal ; Tichopádek, Petr (referee) ; Urbánek, Michal (advisor)
The thesis deals with the study and analysis of crystallographic defects on the surface of silicon wafers produced by Czochralski method. It focuses primarily on growth defects and oxygen precipitates, which play an important role in the development of appropriate nucleation centers for growth of stacking faults. The growth of stacking faults near the surface of silicon wafers is supported by their oxidation and selective etching. Such a highlighted stacking faults are known as the OISF (Oxidation Induced Stacking Fault). Spatial distribution of OISF on the wafer gives feedback to the process of pulling silicon single crystal and wafers surface quality. Moreover the work describes the device for automatic detection and analysis of OISF, which was developed for ON Semiconductor company in Rožnov Radhoštěm.
|
|
|
Design of a photovoltaic power plant with battery storage for a family house in area Ústrašice
Wiesner, Lukáš ; Jandová, Kristýna (referee) ; Vaněk, Jiří (advisor)
The master thesis covers the design of a photovoltaic solar power plant for a selected family house in Ústašice in Tábor’s region The theoretical part summarizes the photovoltaic phenomenon, production, and differences of various technologies of photovoltaic panels and different types of battery storages. The project also includes the legislative and subsidy conditions in the Czech Republic related to the PV topic. The practical part of the thesis starts with information about the layout of the family house with an analysis of household consumption data for the last five years. The analysis is followed by the selection of a suitable type of system for photovoltaic water heating. Using multi-criteria analysis, the most suitable solar controller and PV panels are then selected. The proposed system is updated with other necessary components. Finally, a simulation of the system is created in PV*SOL to determine the lighting conditions and to evaluate the economics side of the entire project.
|
|
|
Vliv technologie pěstování chmele (Humulus lupulus L.) na kvalitu produktu a využití produktu
KLÍMA, Tomáš
The thesis is focused on the technology of hop growing and the quality of the product of hops, i.e., hop cones. The theoretical part of the thesis defines the hop plant in general and varieties produces in the Czech Republic. It also deals with protection against insect and diseases, fertilization of hops and the technology used in cultivation. Finally, the theoretical part deals with the processing of the hop product. In the practical part, the thesis establishes generally valid rules in hop cul-tivation technology. The effect of NanoFYT Si, which contains SiO2 particles, is then tested in a field experiment. This experiment is then evaluated and discussed with previous research on the effect of silicon on field crops.
|
|
|
Study of microdefects in Czochralski silicon
Španělová, Klára ; Cába, Vladislav (referee) ; Másilko, Jiří (advisor)
The bachelor's thesis deals with the study of microdefects in Czochralski silicon in cooperation with the company onsemi Rožnov pod Radhoštěm. The main objectiv is to find knowledge about microdefects in Czochralski silicon and their influence on the properties of semiconductor components. The experimental part deals with the characterization of microdefects in Czochralski silicon ingots doped by B, P and Sb and grown in the company onsemi. Specifically, the measurement of radial resistivity is performance using a four-point probe with subsequent conversion to dopant concentration (according to ASTM F 723-99). The radial and axial distribution of microdefects in Czochralski silicon ingots is evaluated using the precipitation test and the OISF test. The position of the vacant-interstitial interface was also detected as part of microdefect study.
|
guest ::
