Browsing by Author "Gerasimov V."

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Electron beam deflection control system of a welding and surface modification installation
    (2018-04-05) Koleva E.; Dzharov V.; Gerasimov V.; Tsvetkov K.; Mladenov G.
    In the present work, we examined the patterns of the electron beam motion when controlling the transverse with respect to the axis of the beam homogeneous magnetic field created by the coils of the deflection system the electron gun. During electron beam processes, the beam motion is determined the process type (welding, surface modification, etc.), the technological mode, the design dimensions of the electron gun and the shape of the processed samples. The electron beam motion is defined by the cumulative action of two cosine-like control signals generated by a functional generator. The signal control is related to changing the amplitudes, frequencies and phases (phase differences) of the generated voltages. We realized the motion control by applying a graphical user interface developed by us and an Arduino Uno programmable microcontroller. The signals generated were calibrated using experimental data from the available functional generator. The free and precise motion on arbitrary trajectories determines the possible applications of an electron beam process to carrying out various scientific research tasks in material processing.
  • No Thumbnail Available
    Item
    Modeling approaches for electron beam lithography
    (2018-10-19) Koleva E.; Vutova K.; Asparuhova B.; Kostic I.; Cvetkov K.; Gerasimov V.
    In this paper, a study based on the mathematical modelling, applying different process simulation tools (CASINO, TREM, SELID) for characterization of PMMA resist and for the improvement of the resolution concerning the critical dimensions of nano-patterning by electron beam lithography (EBL) is presented. Data for important EBL characteristics (energy deposition function, proximity effect parameters, solubility rate, etc.) are obtained by applying different approaches (Monte Carlo methods, regression models, etc.).