Optimizing and quantifying dopant mapping using a scanning electron microscope with a through-the-lens detector

Abstract

Although dopant contrast in the scanning electron microscope has been known for a long time, its quantification is still a matter of debate mainly due to the lack of understanding of the contrast mechanism. Here we show that dopant contrast can be usefully increased at low extraction voltages. The effect may be related to the different angular and energy distribution of secondary electrons emitted from the p and n regions and for quantitative work should be studied over the full range of extraction potential.