AMPLIFICATION MEASUREMENTS OF ALTERNATIVE IMAGING GASES IN ENVIRONMENTAL SEM

In this paper, we present quantitative data on the amplification behav iour of alternative imaging gases in environmental SEM and describe th e experimental methods used to obtain them. We investigated the gases' amplification abilities over the pressure range 0-12 Torr with respec t to the primary beam energy, detector gap distance and detector accel erating field, in order to isolate optimum imaging conditions for each gas. The gases investigated were, in addition to water vapour, nitrou s oxide, carbon dioxide, nitrogen and helium.