SECONDARY ELECTRON SPECTROSCOPY INSIDE THE SCANNING ELECTRON MICROSCOPE AND ITS MATERIAL SCIENCE APPLICATIONS

Abstract

The scanning electron microscope (SEM) is a powerful high resolution imaging instrument used in multiple fields of study today. The low energy scattered electrons inside it, used mainly for topographic image of a sample’s surface, contain valuable information in the emitted energy spectrum. In this thesis, we extract out this spectral information by using an electron energy analyser attachment. We first present experimental secondary electron (SE) spectral signals, demonstrating the possibility of using them to perform elemental identification, and how SE energy spectroscopy can track and mitigate beam induced contamination. We then present experimental results that lead to new semiconductor characterization possibilities: in-situ native oxide thickness measurements, mapping space-charge regions, characterising the dopant concentration of silicon wafers and junctions that agree well with conventional techniques. It does this by overcoming longstanding problems in the subject of SEM dopant contrast, such as oxide scattering and image contrast reversal.