Low Beam Energy SEM

Abstract

The incident beam energy is one of the most useful parameters over which the microscopist has control because it determines the lateral and depth sampling of the specimen properties by the critical imaging signals. The Kanaya–Okayama electron range varies strongly with the incident beam energy:

$$ {R}_{K-O}(nm)=\left(27.6\ A/{Z}^{0.89}\rho \right){E_0}^{1.67} $$

where A is the atomic weight (g/mol), Z is the atomic number, ρ is the density (g/cm³), and E₀ (keV) is the incident beam energy, which is shown graphically in Fig. 11.1a–c.