Treatment of surfaces with slow electrons

0460200 - ÚPT 2017 RIV CZ eng C - Conference Paper (international conference)
Frank, Luděk - Mikmeková, Eliška
Treatment of surfaces with slow electrons.
Proceedings of the 15th International Seminar on Recent Trends in Charged Particle Optics and Surface Physics Instrumentation. Brno: Institute of Scientific Instruments CAS, 2016 - (Mika, F.), s. 10-11. ISBN 978-80-87441-17-6.
[International Seminar on Recent Trends in Charged Particle Optics and Surface Physics Instrumentation /15./. Skalský dvůr (CZ), 29.05.2016-03.06.2016]
R&D Projects: GA TA ČR(CZ) TE01020118; GA MŠMT(CZ) LO1212; GA MŠMT ED0017/01/01
Institutional support: RVO:68081731
Keywords : electron microscopy * SEM * STEM
Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering
http://www.trends.isibrno.cz/

Historically, the most annoying obstacle to acquiring SEM micrographs, in particular higher magnification micrographs taken with the ambition of resolving the finest observable details, may be said to be carbonaceous contamination “highlighting” the previous field of view with a black rectangle contoured by an even darker frame. This contamination is generated by decomposition of adsorbed hydrocarbon molecules with incident electrons leaving a crosslinked
layer of carbon atoms as a surface coating. The darker contours come from high surface mobility of hydrocarbon molecules from outside the field. The situation has been improved in recent decades by a lower pressure and dryer vacuum in specimen chambers, but even under ultrahigh vacuum (UHV) conditions the phenomenon occurs due to hydrocarbon molecules deposited on the specimen when loaded. Therefore, only in-situ cleaning with an
attachment producing an ion beam solves this problem in UHV, while some plasma cleaners have also started appearing in standard-vacuum SEM chambers. The goal of complete removal of hydrocarbons is motivated by the supposed unavoidability of their decomposition with primary electrons. However, we have found hydrocarbon molecules being released, rather than their decomposition, when the energy of the impinging electrons drops beneath 50 eV or so.
Permanent Link: http://hdl.handle.net/11104/0260332