MICROSCOPY Vol.43▶No.3 2008
â– Feature Articles: Image formation and detection of signal in SEM

Signal Detection in Low Vacuum Scanning Electron Microscopy

Miki Nakamura and Milos Toth

Abstract: Recent advances in low vacuum scanning electron microscopy (LVSEM) have enabled ultra-high resolution secondary electron (SE) imaging of non-conductors, low voltage scanning transmission electron microscopy (STEM) of hydrated and liquid materials, and SE imaging at gas pressures greater than 1kPa. These developments, driven by novel detection strategies that extend the operating parameter space of conventional LVSEM systems, are discussed and illustrated using state-of-the-art images of material systems such as photolithographic masks, aero gels, nanowires, fake snow and influenza virus.

Key words: LVSEM, WET STEM, high resolution