Near Field-Emission Scanning Electron Microscopy with Energy Analysis

We report on new results about near field-emission scanning electron microscopy (NFESEM) which emphasize the potential of generating secondary electrons using a primary electron beam of low energy electrons. Based on scanning tunneling microscopy technology NFESEM uses a sharp W-tip as a cold field emitter, which scans the surface at constant distance, usually in the range of 5 to 40 nm. An applied voltage between tip and sample induces field emission at the tip. These primary electrons are then accelerated towards the target and successively scattered by its surface generating secondary electrons. The last ones, which carry information of the sample, are emitted and energy analyzed. Spatially resolved analysis of energy and polarization of secondary electrons may provide new insight into surface microscopy.