Site-specific dopant profiling in a scanning electron microscope using focused ion beam prepared specimens

Abstract

Site-specific dopant profiling across a silicon p-n junction has been performed in the scanning electron microscope (SEM) on samples prepared using focused ion beam (FIB) milling. The results are compared with the dopant contrast obtained after using non-site-specific cleaving and tripod polishing of specimens. FIB milling generates a damaged surface layer which reduces the dopant contrast observed in the SEM using secondary electron imaging. These results show that two dimensional dopant contrast can be observed from FIB-prepared membranes, thereby extending the application of SEM dopant profiling to the examination of complex nanometer-scale device structures for which site selection is essential.