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Elektrostatické vychylovací a korekční systémy
Badin, Viktor ; Oral, Martin (oponent) ; Zlámal, Jakub (vedoucí práce)
Tato diplomová práce se věnuje prozkoumání možností dynamické korekce vad v elektronové litografii. Pro výpočty byl zvolen elektronový litograf BS600. Práce se zabývá korekcí vad vychýlení třetího řádu: zklenutí pole, astigmatismu a zkreslení. Aberace byly spočteny jak pro současný magnetický vychyolvací systém, tak pro nově navržený elektrostatický deflektor. Vlastnosti a vady obou vychylovacích a korekčních systémů byly porovnány.
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Parasitic Aberrations of Electrostatic Deflectors
Badin, Viktor ; Radlička, Tomáš (oponent) ; Sháněl, Ondřej (oponent) ; Lencová, Bohumila (vedoucí práce)
The present doctoral dissertation deals with parasitic aberrations in electrostatic multipole optical components arising due to mechanical misalignment of the electrodes. Manufacturing and alignment precision of the mechanical parts can have a significant influence on the performance of electron beam machines such as microscopes and lithography (EBL) systems. Defects, imprecisions, and all other symmetry violations generate so-called parasitic fields whose effects on the particle beam are referred to as parasitic aberrations. Perturbations of axially symmetric lenses are usually treated using Sturrock's principle. Displacement or tilt of an entire multipole component can be analyzed in a globally shifted or tilted coordinate system. The present thesis deals with the misalignment of individual electrodes, which cannot be easily described with the mentioned approaches and usually need to be solved in 3D. Calculations in 3D are generally slower and have higher computational requirements than 2D tools standardly used in charged particle optics programs. To calculate parasitic fields generated by electrode misalignment, a 2D perturbation method compatible with the finite element method (FEM) has been developed in this thesis based on shifting the coordinate system locally around the affected electrode. Electrodes misaligned in each axis of the cylindrical coordinate system (longitudinal, radial, and azimuthal) are studied. Possible applications of the derived general method are shown, such as ellipticity and transverse shift of the entire deflector. For each of these cases, the resulting parasitic axial field functions (AFF) calculated in 2D are validated against the 3D solution. In addition to comparing parasitic AFFs, a case study is provided where the effect of parasitic aberrations on the electron beam in an entire optical column of an EBL system is shown, again validated against the 3D solution. The proposed method of calculating parasitic fields in 2D allows understanding the effects of different manufacturing and assembling tolerances, characterizing these effects, designing aberration correction devices, and optimizing mechanical tolerance requirements. The developed method can be run on any standard PC and is 1--2 orders of magnitude faster than solving the perturbed system in 3D.
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Recent Trends in Charged Particle Optics and Surface Physics Instrumentation. Proceedings of the 16th International Seminar
Mika, Filip ; Pokorná, Zuzana
The origins of the seminar “Recent Trends in Charged Particle Optics and Surface Physics Instrumentation” date back into the eighties, when as a part of the isolated “Eastern Bloc”, we were short of English-language books, papers and conferences. In 1990, at the second Seminar, there were as many as 30 participants from 5 countries. The third Seminar in 1992 was moved to hotel Skalský dvur in the Bohemian-Moravian Highlands where it has been held as a biannual meeting ever since.\nThe Seminar takes place in a secluded lakeside hotel surrounded by beautiful nature and calm forests, so all participants have a great possibility to see each other every day and to discuss their topics of interest in more detail. This is a great advantage compared to the huge bustling conferences with their many parallel sections, which are a lively celebration of science but\nsometimes it is difficult to meet there the person with whom you want to discuss a particular scientific topic in more detail.\nFrom the very beginning, the Seminar has been conceived as a meeting devoted more to asking questions not answered yet, than to reporting results. This spirit is usually less present in the introductory presentations and posters but is dominant in the following discussions.\n
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Elektrostatické vychylovací a korekční systémy
Badin, Viktor ; Oral, Martin (oponent) ; Zlámal, Jakub (vedoucí práce)
Tato diplomová práce se věnuje prozkoumání možností dynamické korekce vad v elektronové litografii. Pro výpočty byl zvolen elektronový litograf BS600. Práce se zabývá korekcí vad vychýlení třetího řádu: zklenutí pole, astigmatismu a zkreslení. Aberace byly spočteny jak pro současný magnetický vychyolvací systém, tak pro nově navržený elektrostatický deflektor. Vlastnosti a vady obou vychylovacích a korekčních systémů byly porovnány.
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9th International Conference on Charged Particle Optics. Book of Abstracts
Mika, Filip ; Pokorná, Zuzana
The series of conferences on charged-particle optics was launched in 1980 by Hermann Wollnik together with the late Karl Brown and myself in an attempt to bring together the three main CPO communities, accelerator optics, spectrometer optics and electron optics. All three groups were pleased and somewhat surprised to discover how much they had in common, and it was decided to continue to meet at regular intervals. The fact that so many contributions have been submitted to this ninth meeting shows that the formula is as attractive as ever and the organisers have succeeded in producing a balanced programme with much original material in each of the domains of interest. Brno is well known for major contributions to software for CPO and for low-voltage scanning electron microscopy. There have been exciting developments in all the areas covered by the conference. In electron optics, the successful implementation of aberration correctors for electron microscopes has dominated the literature for the last few years but other aspects of the subject have not been neglected; a session is devoted to ion optics. The optics of accelerators and mass and energy spectrometers is likewise providing many surprises. These proceedings provide a unique snapshot of the world of charged-particle optics in 2014.
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Computations in Charged Particle Optics
Oral, Martin ; Radlička, Tomáš
The design of modern electron microscopes could not be possible without appropriate software tools. With the sub-nanometer resolution in SEM, and the sub-ångström resolution in TEM, one can see that the simulations involved in designing the instruments need to be tremendously accurate. A simulation starts with the computation of the electric and magnetic fields generated by various optical elements. That is followed by determinig the paraxial properties, aberrations and accurate particle trajectories (ray tracing). The distributions of the fields are mostly detemined with the Finite Element Method (FEM), the Boundary Element Method (BEM) or the Finite Difference Method (FDM). As the field data are at the input of all the subsequent calculations, they need to be very accurate, especially in the region close to the optical axis. Current expertise includes a set of rules that need to be applied in generating a FEM or BEM mesh. Advanced field interpolation techniques are necessary for accurate aberration analysis and particle tracing with high-order integration methods. Specialized software has been developped for the use in charged particle optics which aids the user in getting meaningful and accurate results. For instance, the EOD (Electron Optical Design) is a comprehensive package for particle optical sumulations. Field data produced by SIMION and Comsol need a specialized post-processing before their use in accurate ray tracing. Presented will be different methods of computing the optical aberrations, intensity distribution and probe size (resolution) on basic as well as more advanced examples (electron and ion optical columns, deflection systems, ToF spectrometers etc.) that were solved in the EOD and using custom programs.
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Současné trendy v elektronové optice a přístrojové technice pro povrchovou fyziku
Mika, Filip
Sborník semináře o současných trendech v elektronové optice a přístrojové technice pro povrchovou fyziku, který se uskutečnil ve dnech 14.–18. července 2008 v hotelu Skalský dvůr na Českomoravské vrchovině. Akci pravidelně pořádá oddělení Elektronové optiky Ústavu přístrojové techniky AV ČR, v. v. i., a je tradiční příležitostí k setkávání vědců, kteří pracují v oblastech týkajících se vytváření a formování svazků nabitých částic a jejich využití.
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