Energy resolved secondary electron imaging of semiconductor pn junctions using fountain detector

Abstract

We have developed low energy secondary electron (SE) detector for outlens-type scanning electron microscope and named it as fountain detector (FD). Using this FD, we observed pn-junctions in SiC. p-region is darker than n-region in SE images lower than 2 eV, while brighter in those images higher than 2 eV. The comparison of SE spectra indicates the SE spectrum of p-region shifts about 2 eV higher than that of n-region. This FD may open up the new surface potential imaging using low energy SEs.