Thin and semithin sections were extensively examined by the secondary electron (SE) detector in a conventional scanning electron microscope (SEM), and in a transmission electron microscope with a scanning attachment (STEM). Various para-meters, in particular the beam voltage, were shown to affect the final SE image (SEI). As for SEM observation, a surface contrast was imaged at low primary electron (PE) voltages (0.6-2 kV), whereas a subsurface contrast predominated at higher energies (15-30 kV). In STEM, significant differences were not detected by varying the PE in the 20-100 kV range. Surface and subsurface in-formation was simultaneously imaged even though the SEI were better resolved at the highest energy.
Scala, C.; Pasquinelli, G.; Preda, P.; and Laschi, R.
"Beam Voltage Effects in the Study of Embedded Biological Materials by Secondary Electron Detectors,"
Scanning Electron Microscopy: Vol. 1986
, Article 17.
Available at: https://digitalcommons.usu.edu/electron/vol1986/iss3/17