Electron beam damage of chemisorbed surface species: A tunneling spectroscopy study

Electron beam damage is a problem for low-energy electron diffraction, Auger electron spectroscopy, and electron microscopy. We have used tunneling spectroscopy to study the damage caused by 30 keV incident electrons on chemisorbed monolayer films of hexanoic acid, 2,4-hexadienoic acid, and benzoic acid. Our results on monolayer films are compared to existing work on bulk samples. Damage cross sections are similar to bulk values; molecules with more delocalized electrons are more resistant to damage. In contrast to bulk results, however, we find little if any conjugation or cross linking after irradiation.