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Study of chemical cleaning of surfaces by LEIS method
Staněk, Jan ; Polčák, Josef (referee) ; Bábor, Petr (advisor)
This thesis deal with studying chemical etched surfaces of cadmium telluride crystals (CdTe crystals) by low-energy ion scattering spectroscopy (LEIS method). In the theoretical part, there is description of physical essence of LEIS method, including experimental arrangement of Qtac100 instrument, on which the experiment is measured. The LEIS method is also compared with X-ray photoelectron spectroscopy (XPS). There is summary of properties and structure of CdTe crystals including principle of X-ray detectors, which are the primary use of the crystals. In experimental part there is a description of measuring process, starting with a calibration measurement, ongoing with a chemical etching and ending with a surface analysis. There are examples of LEIS spectra with comments and interpretation including comparison with XPS data.
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Calibration of SIMS method by implantation profiles
Janák, Marcel ; Průša, Stanislav (referee) ; Bábor, Petr (advisor)
This bachelor thesis is concerned with a quantitative analysis of the dopant (C, H, Mg, O) distribution in MOCVD-grown AlGaN HEMTs by TOF.SIMS 5 instrument with cesium and oxygen sputtering. The main reason for the development of RSF SIMS measurement quantification method is a hardly predictable phenomenon of preferential sputtering and matrix effect. Calibration samples, prepared by ion implantation technique into homogeneous and periodic III-nitride AlN, GaN structures, are reproduced by an ion-atom interaction program TRIM. A part of this work is likewise a quantification of AlGaN matrix.
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Surface modification by nano-droplets controlled by electron tweezers
Dao, Radek ; Šik, Ondřej (referee) ; Bábor, Petr (advisor)
This master's thesis is focused on the study of the consequences of electron beam induced motion of Au-Ge alloy nanodroplets on germanium surface. The text consists of two parts. The theoretical part gives an overview of measurement and fabrication techniques used for the experiments. The description of these techniques is mainly focused on topics needed to understand the ideas behind the experiments and their results. The topics covered here are the Atomic Force Microscopy, Scanning Electron Microscopy and Electron Beam Lithography. These are followed by an introduction to the gold-germanium material system and the movement of Au-Ge alloy nanodroplets. The practical part gives a roughly chronological guide throughout the whole experimental process, including the search for a suitable sample fabrication method, the surface modification itself and its measurement. Temperature calibration of the heating system is also mentioned.
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Optimization of UHV SEM for nanostructure study in wide temperature range
Axman, Tomáš ; Zigo,, Juraj (referee) ; Bábor, Petr (advisor)
This diploma thesis deals with the optimization of ultra-high vacuum scanning electron microscope - UHV SEM, which is developed within the Amispec project in cooperation with BUT, Institute of Scientific Instruments of the Czech Academy of Science and Tescan Brno, s.r.o. The theoretical part deals with the description of the actual state of the developed equipment and the research of competing systems. The next part describes the optimization of the sample holder and the pallet receptor for studying nanostructures over a wide range of temperatures. Part of the optimization is the sapphire thermal diode development and experimental verification of the functionality of the designed components. This is followed by the verification of the functionality of the whole system for the transport of samples to the UHV area, deposition with effusion cell and in-situ observations.
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Design of the new type of thermal atomic source for oxygen atoms
Šikula, Marek ; Bábor, Petr (referee) ; Mach, Jindřich (advisor)
Ultrathin oxid layers (especially high-k layers) are studied and fabricated by using atomic oxygen sources. These high-k ultrathin layers are integrated into CMOS transistors and DRAM capacitors. In this thesis theory of atomic oxygen beams and ways of theirs creation is summarized. On the basis of the obtained knowledge the engineering design of a unique type of the thermal atomic oxygen source is created. The design was tested by simple experiments. The 3D model and complete engineering drawings are included.
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Testing of the new UHV scanning electron microscope and design of its effusion cel
Šárközi, Rudolf ; Mach, Jindřich (referee) ; Bábor, Petr (advisor)
This work focus on the development and the design of the effusion cell that is able to deposit different materials in downward orientation. The Cell itself should be placed into the ultra-vacuum microscope (UHV-SEM) developed in TESCAN company in the collaboration with Institute of Physical Engineering. Theoretical part is devoted to the description of the electron microscope and its, in the future installed, parts, which will be used for the preparation and the analysis of the nanostructures. In this work, the first measurements with the electron microscope are presented, and the influence of mechanical vibrations to image quality is discussed.
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2D and 3D analysis of semiconductor devices by SIMS
Vařeka, Karel ; Šamořil, Tomáš (referee) ; Bábor, Petr (advisor)
The chemical analysis of semiconductor structures using the SIMS method is the main part of this bachelor thesis. It allows the user to make a depth profiling and a creation of 2D or 3D material images. During the analysis of the chip from the TIGBT semiconductor, there is a sputtering of a heterogeneous structure in the material with different sputtering rates. It is convenient to make a cut through the material using a focused ion beam to create a profile, which grants the user to perform a tomographic measurement. This new surface enables a chemical analysis of a depth profile of semiconductor structures without the need for sputtering beam in dynamic SIMS mode. By reconstructing individual two-dimensional images, it is possible to assemble a three-dimensional pattern of the analysed sample area. Also, the preparation and removal of the lamella from the TIGBT chip were accomplished and analysed via a detector of transmission electrons.
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Quantitative analysis of matrix elements using SIMS and LEIS methods
Staněk, Jan ; Šik, Ondřej (referee) ; Bábor, Petr (advisor)
This thesis studies comparison and connection of two spectrometric methods – low energy ion scattering spektrometry (LEIS) and secondary ion mass spectrometry (SIMS). SIMS method, despite its many positive qualities, suffers of so called matrix effect, which makes quantifiaction of data very difficult. LEIS method on the other hand is immune to this effect and so it’s suitable completion of SIMS method. As a convenient sample have been chosen AlGaN samples with various concentration of gallium and aluminium. In the first part of thesis is introduced physical essence of SIMS and LEIS method, experimental details and studied samples. In second part of the thesis there’s a description of measurements and comparison of data gained by each method.
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Complex ion beam based depth profiling of anticorrosive layers
Holeňák, Radek ; Král, Jaroslav (referee) ; Bábor, Petr (advisor)
Předložená diplomová práce se zabývá implementací metody rentgenové emisne indukované částicemi do experimentálního uspořádání za účelem doplnění rodiny metod založených na iontových technikách, tj. Rutherfordovy zpětné rozptylové spektrometrie, spektrometrie elastického zpětného rozptylu a analýzy detekce doby letu/energie elastického odrazu. Výhoda více-metodického přístupu je demonstrována na vrstvách ze slitin přechodných kovů obsahujících lehké prvky, kde samo-konzistentní analýza poskytuje výrazně zlepšené a přesné informace o stechiometrii, hloubkovém rozložení a tloušťce slitiny. Hmotnostní spektrometrie sekundárních iontů je použita pro porovnání a doplnění získaných výsledků.
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Electron Beam Micromachining of Nonmetalic Materials
Dupák, Libor ; Mrňa, Libor (referee) ; Bábor, Petr (referee) ; Lencová, Bohumila (advisor)
The thesis deals with electron beam micromachining of nonmetallic materials like glass, ceramics and plastics. A brief description of the device on which the experiments were carried out is included; the author has participated on its development. Main topic is experimental study of influence of main electron beam parameters on results of machining. Examined parameters include accelerating voltage, beam current, focusing and speed of machining. Influence of beam deflection is analyzed. Method of sequential machining by repeated passes of the electron beam is presented. Main examined materials are quartz glass, alumina and selected plastics. The usefulness of the technology is shown by several practical applications.
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