Secondary electron hyperspectral imaging: Nanostructure and chemical analysis for the LV-SEM

Abstract

Materials engineers have increasing control over nanoscale chemical composition and nanostructures. The latter can be easily analysed by the scanning electron microscope (SEM) yet nanoscale chemical analysis in the SEM poses challenges. Nevertheless, nanoscale chemical analysis capabilities have been developed in the LV-SEM by secondary electron hyperspectral imaging (SEHI). In this article, the insights that SEHI has provided into well characterised semiconductor, photovoltaic, polymer and hard carbon materials are reviewed. Instrument and experimental considerations for the obtainment of secondary electron hyper-spectra are discussed and recommendations for future analyses in the LV-SEM by SEHI are made.

Optimized dopant imaging for GaN by a scanning electron microscopy

“…Numerical results have shown that the doping contrast is mainly a function of bulk built-in voltages of the p-n junction. [23][24][25] However, the doping contrast formation is also dependent on the local external electric field, 26,27 surface band-bending field, 28,29 metal-semiconductor contacts, [30][31][32][33] refraction effects at the semiconductor-vacuum interface 34,35 and the collection solid angle of the SE detector. 24,36,37 Gallium nitride (GaN), one of the third-generation wide bandgap semiconductors, has received much attention owing to its high breakdown electric fields, high thermal conductivity, good chemical stability and strong irradiation resistance (related to its high internal and external quantum efficiencies).…”

“…Numerical results have shown that the doping contrast is mainly a function of bulk built‐in voltages of the p‐n junction 23–25 . However, the doping contrast formation is also dependent on the local external electric field, 26,27 surface band‐bending field, 28,29 metal–semiconductor contacts, 30–33 refraction effects at the semiconductor–vacuum interface 34,35 and the collection solid angle of the SE detector 24,36,37 …”