J 2019

Statistical Coulomb interactions in multi-beam SEM

STOPKA, Jan a Pieter KRUIT

Základní údaje

Originální název

Statistical Coulomb interactions in multi-beam SEM

Autoři

STOPKA, Jan a Pieter KRUIT

Vydání

INTERNATIONAL JOURNAL OF MODERN PHYSICS A, SINGAPORE, WORLD SCIENTIFIC PUBL CO PTE LTD, 2019, 0217-751X

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Utajení

není předmětem státního či obchodního tajemství

Impakt faktor

Impact factor: 1.486

DOI

UT WoS

000516718800022

Klíčová slova anglicky

Coulomb interactions; trajectory displacement; multi-beam SEM; electron optics; slice method

Štítky

Příznaky

Mezinárodní význam, Recenzováno
Změněno: 20. 7. 2020 18:14, Mgr. Jan Stopka, Ph.D.

Anotace

V originále

Statistical Coulomb interactions in conventional scanning electron microscopy mostly affect the probe size via energy spread and virtual source broadening in the emitter vicinity. However, in a multi-beam probe forming system such as a multi-beam scanning electron microscopes (MBSEM), the trajectory displacement due to interactions in the whole column can give a contribution to the final probe size. For single-beam systems, this can be expressed using approximate formulae for the total trajectory displacement in a beam segment (Jansen's theory) or by integrating contributions of infinitesimally thin beam slices (the slice method). We build on Jansen's theory of statistical Coulomb interactions and develop formulae for the trajectory displacement in a multi-beam system. We also develop a more precise semi-analytical result using the slice method. We compare both approaches with a Monte Carlo simulation and show a good agreement with the results of the slice method. Finally, we discuss the implications of our results for the optical design of multi-beam SEM. In a multi-beam with probe size dominated by Coulomb interactions, an increase in the number of beamlets does not necessarily provide an increase of throughput, because the probe size is limited by the total current. Furthermore, we disprove the notion of "the fewer the crossovers - the less the Coulomb interactions" by showing the quadratic dependence of trajectory displacement on segment length.