Secondary electron spectroscopy for imaging semiconductor materials

The “fountain detector (FD)”, which is a low-pass secondary electron detector in a scanning electron microscope (SEM), has been developed in order to visualize the surface potential variation or the dopant density for semiconductor materials. A 4H-SiC p-n junction, which has different dopant densities in the p-region, was observed and energy spectra with FD were compared to the spectra with Auger spectra across the p-n junction. The energy spectra with FD shows the same tendency on those spectra with Auger and clearly identify differences between not only p- and n-regions but the different dopant densities in p-region.