National Repository of Grey Literature 15 records found  1 - 10next  jump to record: Search took 0.01 seconds. 
Automation and control of multilayers deposition by IBS/IBAD
Pavera, Michal ; Sobota, Jaroslav (referee) ; Urbánek, Michal (advisor)
This diploma thesis deals with the automation of the deposition process by ion beam sputtering and ion beam assisted deposition. This work contains drawings of mechanical adjustments of the deposition chamber designed to control shutter and rotation of the target using stepper motors. There are presented ways to control stepper motors and troubleshoot their exact settings. Another task is to design a system for computer control of the deposition process. There are discussed ways to control the ion sources, pressure meter, flow meter and thickness meter, and their connection to a PC via RS-232 and analog-digital converters. It is also designed control program in LabVIEW, which allow automated multilayer deposition. Last part of the thesis deals with testing automatic deposition and results are commented.
Development and Application of an UHV Equipment for Deposition of Thin Films (Atomic and Ion Systems)
Mach, Jindřich ; Čech, Vladimír (referee) ; Lencová, Bohumila (referee) ; Šikola, Tomáš (advisor)
In the thesis the development of two equipment for preparation of ultrathin films under ultrahign vacuum conditions (UHV) is discussed. Here, additionally to a brief description of theoretical principles, more details on the design of these units are given. In the first part the design of a thermal source of oxygen or hydrogen atomic beams is discussed. Further, a design and construction of an ion–atomic beam source for ion-beam assisted deposition of thin films is detailed. The source combines the principles of an efusion cell and electron-impact ion beam source generating ions of (30 – 100) eV energy. The source has been successfully applied for the growth of GaN on the Si(111) 7x7 substrate under room temperature.
The deposition of Ga and GaN nanostructures on silicon and graphene substrate
Novák, Jakub ; Jarý, Vítězslav (referee) ; Mach, Jindřich (advisor)
The thesis is focused on the study of properties of GaN nanocrystals and Ga structures on the surface of silicon and graphene substrate. In the theoretical part of this thesis, the basic properties of Ga/GaN and graphene are described, as well as their applications or connection of both structures together in different devices. The ability of metal nanoparticles to enhance not only photoluminescence, due to the interaction of the material with surface plasmons, is also shown in several examples. The experimental part of the work first deals with the production and characterization of graphene sheets prepared by Chemical Vapor Deposition. Ga/GaN growth on both types of substrates was performed in a UHV chamber using an effusion cell for Ga deposition and an atomic ion source for nitridation. Prepared structures were characterized using various methods (XPS, SEM, AFM, Raman spectroscopy or photoluminescence). In the last step, GaN nanocrystals were coated with Ga islands to study the photoluminescence enhancement.
Computer control of the deposition process
Pavera, Michal ; Voborný, Stanislav (referee) ; Urbánek, Michal (advisor)
This bachaloers thesis deals with automation of the deposition process of the ultrathin layers by IBAD method. One of the tasks is to design motorized target and shutter manipulator. The thesis therefore contain drawings of these manipulators. Which enable their control by stepper motors. Second task is to design of electronics and program control of primary and secondary ion source. In this part is described connection of the system with the computer using AD/DA converters and the appropriate programming. Last part of the thesis deals with differences between automated and manual control of the system, their advantages and disadvantages.
Deposition of GaN nanocrystals with Ga droplets
Novák, Jakub ; Voborný, Stanislav (referee) ; Mach, Jindřich (advisor)
This bachelor thesis deals with preparation and characterization of Ga structures and GaN nanocrystals. In the theoretical part, properties and applications of GaN are introduced. Further, some substrates for the growth and some techniques used for manufacturing of these structures are stated. Further, is also mentioned the photoluminiscence of GaN. The experimental part deals with preparation of Ga and GaN structures and combination of both. These structures were further analyzed by various methods such as XPS, SEM or photoluminiscence.
Fabrication of plasmonic antennas for analytical transmission electron microscopy by focused ion beam lithography
Foltýn, Michael ; Kejík, Lukáš (referee) ; Horák, Michal (advisor)
This bachelor thesis is focused on sputtering of thin gold layers and manufacturing of plasmonic antennas using focused ion beam lithography. I optimised the process of sputtering of gold layers by ion beam assisted deposition. Furthermore, I optimised processes connected to manufacturing of plasmonic antennas by focused ion beam lithography. I sputtered thin gold layers 20, 30 and 40 nm thick by various deposition rates. In terms of grain size, the best layers were those deposited with rate of 2 /s. From view of crystallographic composition, the best results were achieved by using deposition rates of 0.2 and 3 /s. I made 3 types of antennas. Rod shaped antennas of 240 nm in length and widths of 40 and 80 nm, and bowtie antenna with 20 nm gap in between its wings. I further optimised parameters of ion etching for each thickness and deposition rate of sputtered layers used for creating antennas mentioned before. The highest quality of antennas was achieved when using layers 20 and 40 nm thick. For manufacturing of bowtie antennas however, layers of all thicknesses deposited by rate of 3 /s were optimal. I discovered, that for layers deposited with rate of 2 /s a lot of redeposited material got sputtered back on to antennas, which can bring the diameters of antennas closer to the desired value at least in one axis.
The deposition of thin films by the ion sputtering IBS/IBAD
Hudeček, Jan ; Pavera, Michal (referee) ; Dvořák, Petr (advisor)
The submitted bachelor’s thesis are dealed with concept and design of holder of new palette, which is determine for deposition equipment, which belongs to institue of physical engineering and which is called as Kaufmann. Introductory chapters of bachelor’s thesis deals about possibilities of production of thin films, ways of growth of thin films and introduction to vakuum physics. Next chapter is given to current deposition and current deposition equipment Kaufmann. In the next chapter are descriptions of construct solution of holder of new palette and construct solution of palette. The last chapter is given to calibration and optimalization of deposition with new palette.
Fabrication of plasmonic antennas for analytical transmission electron microscopy by focused ion beam lithography
Foltýn, Michael ; Kejík, Lukáš (referee) ; Horák, Michal (advisor)
This bachelor thesis is focused on sputtering of thin gold layers and manufacturing of plasmonic antennas using focused ion beam lithography. I optimised the process of sputtering of gold layers by ion beam assisted deposition. Furthermore, I optimised processes connected to manufacturing of plasmonic antennas by focused ion beam lithography. I sputtered thin gold layers 20, 30 and 40 nm thick by various deposition rates. In terms of grain size, the best layers were those deposited with rate of 2 /s. From view of crystallographic composition, the best results were achieved by using deposition rates of 0.2 and 3 /s. I made 3 types of antennas. Rod shaped antennas of 240 nm in length and widths of 40 and 80 nm, and bowtie antenna with 20 nm gap in between its wings. I further optimised parameters of ion etching for each thickness and deposition rate of sputtered layers used for creating antennas mentioned before. The highest quality of antennas was achieved when using layers 20 and 40 nm thick. For manufacturing of bowtie antennas however, layers of all thicknesses deposited by rate of 3 /s were optimal. I discovered, that for layers deposited with rate of 2 /s a lot of redeposited material got sputtered back on to antennas, which can bring the diameters of antennas closer to the desired value at least in one axis.
The deposition of Ga and GaN nanostructures on silicon and graphene substrate
Novák, Jakub ; Jarý, Vítězslav (referee) ; Mach, Jindřich (advisor)
The thesis is focused on the study of properties of GaN nanocrystals and Ga structures on the surface of silicon and graphene substrate. In the theoretical part of this thesis, the basic properties of Ga/GaN and graphene are described, as well as their applications or connection of both structures together in different devices. The ability of metal nanoparticles to enhance not only photoluminescence, due to the interaction of the material with surface plasmons, is also shown in several examples. The experimental part of the work first deals with the production and characterization of graphene sheets prepared by Chemical Vapor Deposition. Ga/GaN growth on both types of substrates was performed in a UHV chamber using an effusion cell for Ga deposition and an atomic ion source for nitridation. Prepared structures were characterized using various methods (XPS, SEM, AFM, Raman spectroscopy or photoluminescence). In the last step, GaN nanocrystals were coated with Ga islands to study the photoluminescence enhancement.
Deposition of GaN nanocrystals with Ga droplets
Novák, Jakub ; Voborný, Stanislav (referee) ; Mach, Jindřich (advisor)
This bachelor thesis deals with preparation and characterization of Ga structures and GaN nanocrystals. In the theoretical part, properties and applications of GaN are introduced. Further, some substrates for the growth and some techniques used for manufacturing of these structures are stated. Further, is also mentioned the photoluminiscence of GaN. The experimental part deals with preparation of Ga and GaN structures and combination of both. These structures were further analyzed by various methods such as XPS, SEM or photoluminiscence.

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