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Structural Colors of Self-Similar Nano Patterns
Meluzín, Petr ; Horáček, Miroslav ; Krátký, Stanislav ; Kolařík, Vladimír
E-beam lithography is a flexible technology for various diffraction gratings origination. The e-beam patterning typically allows for the creation of optical diffraction gratings in the first diffraction order. However, the very high resolution enables also the patterning of structures providing the zero-order diffraction. Recently, we presented a work on the structural colors of metallic layers covering both regular-line structures and CGH (computer generated hologram) structures. This work presents a study dealing with zero-order diffraction structures with self-similar properties. The practical part of the work is focused on two aspects: design parameters and technological issues. Variations in design parameters include the tone of the structure (positive or negative),\nthe density of filling, the filling factor, and the depth of the structures. The achieved gamut of colors may by primarily extended by the proper selection of metal deposition technology and its parameters, and further by the proper selection of the metal and the thickness of its layer, these are the technological issues.
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Phyllotactic Model Linking Nano and Macro World
Horáček, Miroslav ; Meluzín, Petr ; Krátký, Stanislav ; Urbánek, Michal ; Bok, Jan ; Kolařík, Vladimír
Recently, the arrangement of diffraction primitives according to a phyllotactic model was presented. This arrangement was used to benchmarking purposes of the e-beam writer nano patterning. The phyllotactic arrangement has several interesting properties. One of them is related with the coherence between the nanoor microscopic domain of individual optical primitives and the properties of visually perceived images crated by these structures in the macro domain. This paper presents theoretical analysis of the phyllotactic arrangement in the referred context. Different approaches enabling the creation of diffractive optically variable images are proposed. The practical part of the presented work deals with the nano patterning of such structures using two different types of the e-beam pattern generators. One of them is a system with a variable shaped beam of electrons, while the other one is a system with a Gaussian-shaped beam. E-beam writing strategies and the use of inherent spiral patterns for exposure ordering and partitioning are also discussed.
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SMV-2016-03: Přesné reliéfní struktury
Matějka, Milan ; Horáček, Miroslav ; Meluzín, Petr ; Chlumská, Jana ; Král, Stanislav ; Kolařík, Vladimír ; Krátký, Stanislav ; Fořt, Tomáš ; Oulehla, Jindřich ; Šerý, Mojmír
Vývoj v oblasti realizace přesných reliéfních struktur pomocí elektronové litografie a dalších ultra precizních mikrovýrobních technik.
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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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Bandpass filter for secondary electrons in SEM - experiments
Mika, Filip ; Konvalina, Ivo ; Krátký, Stanislav ; Müllerová, Ilona
Bandpass energy filtering using a through-the-lens secondary electron (TLD) detector in a field emission gun SEM (FEG-SEM) has been known over a decade. During energy filtering, image contrast is changed and new information about the material can be observed. Our motivation for this study was to compare theoretical calculations with the experimental data\nof the SE bandpass energy filter in Magellan 400 FEG SEM. The TLD detector works as a bandpass energy filter for the special setup of electrode potentials inside the objective lens, with the positive potential on the specimen regulating the energy window.
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