Scanning transmission low-energy electron microscopy

0367292 - ÚPT 2012 RIV US eng J - Journal Article
Müllerová, Ilona - Hovorka, Miloš - Konvalina, Ivo - Unčovský, M. - Frank, Luděk
Scanning transmission low-energy electron microscopy.
IBM Journal of Research and Development. Roč. 55, č. 4 (2011), 2:1-6. ISSN 0018-8646. E-ISSN 2151-8556
R&D Projects: GA AV ČR IAA100650902; GA MŠMT ED0017/01/01
Institutional research plan: CEZ:AV0Z20650511
Keywords : TEM * STEM * SEM
Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering
Impact factor: 0.723, year: 2011

We discuss an extension to the transmission mode of the cathode-lens-equipped scanning electron microscope, enabling operation down to the lowest energies of electrons. Penetration of electrons through free-standing ultrathin films is examined along the full energy scale, and the contribution of the secondary electrons (SEs), released near the bottom surface of the sample, is shown, enhancing the apparent transmissivity of the sample to more than 100%. Provisional filtering off of the SEs, providing the dark-field signal of forward-scattered electrons, was made using an annular 3-D adjustable detector inserted below the sample. Demonstration experiments were performed on the graphene flakes and on a 3-nm-thick carbon film. Electron penetrability at the lowest energies was measured on the graphene sample.
Permanent Link: http://hdl.handle.net/11104/0202028