Experiments and simulations of electron transport in materials

0456254 - ÚPT 2016 CZ eng A - Abstract
Walker, Christopher - Mika, Filip - Konvalina, Ivo - Müllerová, Ilona - Frank, Luděk
Experiments and simulations of electron transport in materials.
Mikroskopie 2015. Praha: Československá mikroskopická společnost, 2015. s. 23-24.
[Mikroskopie 2015. 12.05.2015-13.05.2015, Lednice]
R&D Projects: GA TA ČR(CZ) TE01020118; GA MŠMT(CZ) LO1212; GA MŠMT ED0017/01/01
Institutional support: RVO:68081731
Keywords : electron transport in materials
Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

Although there have been many studies and Monte Carlo (MC) simulations undertaken to simulate the transport of electrons with energies above 5 keV through materials, the simulation of electron transport in order to achieve quantification in a Scanning Electron Microscope (SEM) is much rarer. The reason for this is twofold. First, up to now, it has been difficult to obtain a quantified signal in a Scanning Electron Microscope (SEM) and second, the uncertainties and complications of simulating low energy electrons are much greater. Among the simulation problems that are faced are increased influence of the crystallinity, (e.g. band structure and diffraction), uncertainities in the elastic scattering probabilities, apparent reduction in the inelastic mean free path below that which is predicted. Even though these problems are most acute at energies below 50eV, quantification at higher energies in an SEM also presents difficulties. As a test of quantification procedures at higher energies, a comparison of experimental and MC simulation for electron beams transmitted through thin films was carried out. The SEM used was an FEI Magellan 400 [1] and a detector consisting of several annular rings was placed under the beam. The thin film specimen was placed between the electron column and the STEM detector. The electron trajectories are heavily influenced by the magnetic field of the objective lens, and have to be taken into account in the simulation. MC simulations were carried out using the program of ref. and the simulations in the magnetic field used EOD. Fig. 3 shows an experiment-simulation comparison for the case of Au 100nm film at 15keV primary energy and shows reasonable agreement. The goal is now to explore energies at lower primary beam energies.
Permanent Link: http://hdl.handle.net/11104/0256812