Comparative study of field emission-scanning electron microscopy and atomic force microscopy to assess self-assembled monolayer coverage on any type of substrate

In this work, we show how field emission-scanning electron microscopy (FE-S EM) can be a useful tool for the study of self-assembled monolayer systems. We have carried out a comparative study using FE-SEM and atomic force micr oscopy (AFM) to assess the morphology and coverage of self-assembled monola yers (SAM) on different substrates. The results show that FE-SEM images pre sent the same qualitative information obtained by AFM images when the SAM i s deposited on a smooth substrate (e.g., mica). Further experiments with ro ugh substrates (e.g., Al grains on glass) show that FE-SEM is capable of un ambiguously identifying SAMs on any type of substrate, whereas AFM has sign ificant difficulties in identifying SAMs on rough surfaces.