Amplification measurements of alternative imaging gases in environmental SEM

In this paper, we present quantitative data on the amplification behaviour of alternative imaging gases in environmental SEM and describe the experimental methods used to obtain them. We investigated the gases' amplification abilities over the pressure range 0-12 Torr with respect to the primary beam energy, detector gap distance and detector accelerating field, in order to isolate optimum imaging conditions for each gas. The gases investigated were, in addition to water vapour, nitrous oxide, carbon dioxide, nitrogen and helium.