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Difraction in a scanning electron microscopie
Řiháček, Tomáš ; Mika, Filip ; Matějka, Milan ; Krátký, Stanislav ; Müllerová, Ilona
Manipulation with the primary beam phase in a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM) has drawn significant attention in the microscopy community in the recent years. Although a few applications were found long before, some are still subjects of a future research. One of them is the use of electron vortex beams, which has very promising potential. It ranges from probing magnetic materials and manipulating with nanoparticles to spin polarization of a beam in an electron microscope.\nThe methods for producing electron vortex beams have undergone a lot of development in recent years as well. The most versatile way is holographic reconstruction using computer-generated holograms modifying either phase or amplitude. As the method is\nbased on diffraction, beam coherence is a very important parameter here. It is usually performed in TEM at energies of about 100 – 300 keV which are well suited for diffraction on artificial structures for two reasons. The coherence of the primary beam is often reasonable, and the diffraction pattern is easily observed. This is however not the case for a standard scanning electron microscope (SEM) with typical energy up to 30 keV.
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Large-area gray-scale structures in e-beam writer versus area current homogeneity and deflection uniformity
Kolařík, Vladimír ; Horáček, Miroslav ; Matějka, Milan ; Krátký, Stanislav ; Bok, Jan
The high stability and good current homogeneity in the spot of the e-beam writer is crucial to the exposure quality, particularly in the case of large-area structures when gray-scale lithography is used. Even though the deflection field distortion is calibrated regularly and beam focus and beam astigmatism is dynamically corrected over the entire deflection field,\nwe can observe disturbances in the exposed relief for both nowadays types of e-beam writers, the shaped e-beam writing system and the Gaussian e-beam writing system. A stable and homogeneous angular current density distribution in the spot is important especially in the case of shaped e-beam lithography systems. A non-homogeneity of the spot over deflection field is seen alongside the field boundaries of both lithography systems.
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Properties study of periodic gratings prepared by electron-beam lithography
Krátký, Stanislav ; Opletal, Petr (referee) ; Matějka, Milan (advisor)
This study examines the process of the relief periodic structures creation by way of electron beam lithography. It describes how to design these structures by means of a computer and subsequently how to create them by electron beam lithograph. Moreover, this study explores the methods by which these structures are measured and evaluated. These methods are used to measure and evaulate binary periodic gratings and thanks to obtained data it can be determined the dependence of the depth of grating on its period. The study also contains measurement of diffraction efficiency on manufactured gratings and comparison of the dependence of its diffraction efficiency on the depth of grating.
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The silicon etching technology
Krátký, Stanislav ; Ježek,, Jan (referee) ; Matějka, Milan (advisor)
This thesis deals with the silicon etching technology. It Examines using of water solution of potassium hydroxide. It focuses on plasma etching of silicon using mixture of CF4 and O2 as the dry way of etching. Important parameters of etching like etching rate of silicon and masking materials, etching selectivity, surface roughness and underetching of mask are determined for both ways. Some additional processes has been examined as well, namely creating of mask of resist and silicon dioxide, lithography process and etching of resist using oxygen plasma.
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Observation of Insulators in ESEM
Matějka, Milan ; Špinka, Jiří (referee) ; Jirák, Josef (advisor)
This graduation theses in introduction deals with principle and problems of electron signal detection in scanning electron microscopy and charging of insulating specimens in SEM. The experimental part of the thesis describe the methods of qualification and quantification of insulating specimen charging effect observed in environmental scanning electron microscope through the use of ionisation and scintillation detector in dependence on water vapour pressure in specimen chamber. The goal of the thesis is formation of the methodics useful to evaluate charging effect at insulating specimens observing and on the basis of measuring, determine optimal conditions for insulating specimen observation with ionisation and scintillation detector.
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SMV-2015-15: Development of combined amplitude/phase photo masks
Horáček, Miroslav ; Kolařík, Vladimír ; Matějka, Milan ; Krátký, Stanislav ; Chlumská, Jana ; Meluzín, Petr ; Král, Stanislav
Research and development in the field of physical realization of transparent and opaque optical structures by means of electron beam lithography in a recording material supported by a glass substrate. The research covers the analysis of the graphical motive, its topology and morphology, research and application of binary and relief structures performing required graphical and optical properties, development of technology for the preparation of combined photo masks that process both the amplitude and the phase of the light beam, verification of optical properties of such masks.
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SMV-2015-14: Development of e-beam lithography technology
Horáček, Miroslav ; Kolařík, Vladimír ; Matějka, Milan ; Krátký, Stanislav ; Chlumská, Jana ; Meluzín, Petr ; Král, Stanislav
Development of the devices for electron beam lithography technology. Research and development cover the complete lithography system, in particular Schottky Zro/W electron emitter, electron optical column including beam forming system, X-Y stage, high vacuum system, control system electronics.
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SMV-2015-13: Relief structures based on diffractive optics
Krátký, Stanislav ; Kolařík, Vladimír ; Horáček, Miroslav ; Matějka, Milan ; Chlumská, Jana ; Meluzín, Petr ; Král, Stanislav
Research and development in the field of physical realization of optical structures based on the principle of diffractive optics by means of electron beam lithography in a recording material supported by a silicon or glass board. The research covers the analysis of the optical motive, research and application of relief structures implementing the required optical properties, research and modeling of the physical possibilities of implementation of relief structures, preparation and analysis of technology of implementation of relief structures with regard to the limits of current scientific instruments, verification of theoretical considerations by means of relief structure sample exposure.
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SMV-2015-12: Relief structures based on diffractive optics
Horáček, Miroslav ; Kolařík, Vladimír ; Matějka, Milan ; Krátký, Stanislav ; Chlumská, Jana ; Meluzín, Petr ; Král, Stanislav
Research and development in the field of physical realization of graphic and optical structures based on the principle of diffractive optics by means of electron beam lithography in a recording material supported by a silicon or glass board. The research covers the analysis of the graphical or optical motive, research and application of relief structures implementing the required graphic and optical properties, research and modeling of the physical possibilities of implementation of relief structures, preparation and analysis of technology of implementation of relief structures with regard to the limits of current scientific instruments, verification of theoretical considerations by means of relief structure sample exposure.
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