National Repository of Grey Literature 15 records found  1 - 10next  jump to record: Search took 0.00 seconds. 
SMV-2019-06: Development of test specimens for SEM
Matějka, Milan ; Horáček, Miroslav ; Meluzín, Petr ; Chlumská, Jana ; Král, Stanislav ; Kolařík, Vladimír ; Krátký, Stanislav ; Knápek, Alexandr
Contract research is concerned with the development of precision relief structures in silicon for testing of scanning electron microscopy (REM) imaging. Micro lithographic techniques for silicon processing and other related technological processes have been developed for the calibration specimen preparation.
Silver micro drop structured twice around the earth
Meluzín, Petr ; Tryhuk, V. ; Horáček, Miroslav ; Knápek, Alexandr ; Krátký, Stanislav ; Matějka, Milan ; Kolařík, Vladimír
Planar micro structuring of thin metallic layers allows to achieve required surface properties of metallic layers covering bulk materials. Recently, the arrangement of micro holes or pillars placed around the primary spiral according to a phyllotactic model was presented. This deterministically aperiodic planar arrangement was used for benchmarking purposes of the e-beam writer patterning. This arrangement based on single primary spiral and a variety of derived secondary spirals has several interesting properties. One of them is a very low ratio between the area populated by individual micro elements and the length of the primary phyllotactic spiral. This paper presents analysis of the phyllotactic spiral length and the rising gradient at the spiral outer edge. The practical part of the presented work deals with the patterning of a thin silver layer deposited on the silicon or glass substrates using e-beam pattern generation, lithography techniques and related technologies. An interesting impact of the mentioned spiral properties on the e-beam writing strategies and the exposure ordering strategy are also discussed.
SMV-2018-05: Development of test specimens for SEM
Matějka, Milan ; Horáček, Miroslav ; Meluzín, Petr ; Chlumská, Jana ; Král, Stanislav ; Kolařík, Vladimír ; Krátký, Stanislav ; Knápek, Alexandr
Development in the field realization of precise relief structures in the silicon dedicated to the testing of the scanning electron microscopes (SEM) deflection field and accuracy. Micro-lithographic techniques for the recording of patterns in the silicon were used. New tools for handling during technological operations of resist deposition and etching were developed. Optimization was reached in the process of transfer of the relief structure into silicon via anisotropic etching, due modification of etching apparatus. Standardized procedures for inspection and quality control were developed.
Hiding e-beam exposure fields by deterministic 2D pattering
Horáček, Miroslav ; Knápek, Alexandr ; Matějka, Milan ; Krátký, Stanislav ; Urbánek, M. ; Mika, Filip ; Kolařík, Vladimír
The high stability and good current homogeneity in the spot of the e-beam writer is crucial to\nthe exposure quality, particularly in the case of large-area structures when gray-scale\nlithography is used. Even though the deflection field distortion is calibrated regularly and\nbeam focus and beam astigmatism is dynamically corrected over the entire deflection field, we can observe disturbances in the exposed relief.\nRecently, we presented a method that makes use of e–beam exposure imperfection by\nintroducing marginally visible high–frequency diffraction gratings of variable pitch that fill in\nseparate orthogonal exposure fields. The actually presented approach follows up our\nresearch on aperiodic arrangements of optical primitives, especially on the phyllotactic–\nlike arrangement of sub–micron relief optical elements. This approach is extended from the\ndiffraction element arrangement to the higher level of exposure fields arrangements.
Field emission from W5O14 nanowires
Saqib, M. ; Knápek, Alexandr ; Jelenc, J. ; Pirker, L.
The W5O14 (O/W=2.8) nanowires are metallic oxides with specific resistivity of 25 microOhm/cm and\ndiameters bellow 100 nm [1]. They were synthesized by iodine transport method using nickel\nas a growth promoter and WO3 as source of tungsten and oxygen. The field emission\ncharacteristics of single nanowires [2] and the films composed of these nanowires have been\nreported [3]. The emitting current densities up to 6.4 mA/cm2 have been obtained at relatively\nlow average electric field of about 3 V/Ohm*m. The samples were allowed to emit for more than\n100 hours without showing significant decays of the emitting current and without substantial\ncurrent oscillations. Here, we present field emission properties of single W5O14 nanowires\nexposed to two ranges of average electric fields (0.7–0.85 V/Ohm*m and up to 37–39 V/Ohm*m.
Noise behaviour of field emission cathode based on lead pencil graphite
Knápek, Alexandr ; Horáček, Miroslav ; Hrubý, František ; Šikula, J. ; Kuparowitz, T. ; Sobola, D.
The paper describes electrical noise of experimental field emission cathodes based on “polymer” pencil leads which have a high content of hybridized carbon with a low degree of surface oxidation and silicon monoxide (SiO). Charge transport within experimental samples is evaluated based on results provided by the noise spectroscopy method. The paper also briefly describes the experimental preparation method of graphite tips based on ion milling which allow obtaining ultrasharp tips of a diameter lower than 100 nm.
SMV-2017-06: Development of test specimens for SEM
Matějka, Milan ; Horáček, Miroslav ; Meluzín, Petr ; Chlumská, Jana ; Král, Stanislav ; Kolařík, Vladimír ; Krátký, Stanislav ; Knápek, Alexandr
Research and development in the field realization of precise relief structures in the silicon dedicated to the testing of the scanning electron microscopes (SEM) deflection field and accuracy.
Deterministic Aperiodic Image Device
Horáček, Miroslav ; Meluzín, Petr ; Krátký, Stanislav ; Knápek, Alexandr ; Mika, Filip ; Chlumská, Jana ; Matějka, František ; Král, Stanislav ; Brunn, Ondřej ; Giričová, D. ; Kopal, Jaroslav ; Kolařík, Vladimír
The paper deals with the analysis, design and preparation of a diffractive optically variable imaging device consisting of a deterministic aperiodic mesh formed by basic optical elements. The theoretical basis is complemented by numerical analysis and presentation of the implemented master and its replicas.
Scanning very low energy electron microscopy for the characterization of polycrystalline metal samples
Pokorná, Zuzana ; Knápek, Alexandr
We explored the possibility of a Scanning Electron Microscopy technique for the determination of crystallographic orientation, based on the measurement of the reflectivity of very low energy electrons. Our experiments are based on the concept that in the incident electron energy range 0–30 eV, electron reflectivity can be correlated with the electronic structure of the material, which varies with the local crystallographic orientation of the specimen.\nThe motivation for the development of this technique was to achieve a quick and highresolution means for determining the crystallographic orientation of very small grains in a polycrystalline material. The key limiting factor was the cleanliness of the sample surface and also the geometrical setup of the experiment.
Field emission from the surface of highly ordered pyrolytic graphite
Knápek, Alexandr ; Pokorná, Zuzana
This paper deals with the electrical characterization of highly ordered pyrolytic graphite (HOPG) surface based on field emission of electrons. The effect of field emission, occurs only at disrupted surface, i.e. surface containing ripped and warped shreds of the uppermost layers of graphite. These deformations provide the necessary field gradients which are required for measuring tunneling current caused by field electron emission. Results of the field emission measurements are correlated with other surface\ncharacterization methods such as scanning near-field optical microscopy (SNOM) or atomic force microscopy. A simple method utilizing the field emission of electrons has been devised to characterize the sample surface. Electron and probe microscopies were used to determine the structure of both the bulk sample and the partially exfoliated shreds of the uppermost layers of graphite in locations where field emission is observed.

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See also: similar author names
1 Knapek, Adam
1 Knápek, A.
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