Experimental secondary electron spectra under SEM conditions

Abstract

SummarySecondary electron spectra have been collected from both pure elements and from compounds examined under conditions approximating those found in a scanning electron microscope. Despite the presence of substantial surface contamination these spectra are found to be reproducible and characteristic of the underlying material. Typically the peak in such spectra is found to be at an energy of about 5 eV, and 50% of the total secondary electron emission falls within the range 0-12 eV. These data may be of value for the design of detectors for scanning microscopy and might have applications for microanalysis.

Monte Carlo Simulation of SEM and SAM Images

“…In our previous studies reasonable values of secondary yield and satisfactory energy distribution curves as well as backscattering energy spectra (Ding et al, 2001;Ding et al, 2004b) have been successfully obtained, which has proved the reasonability of this MC model. For Si considered here, by using the full-Penn algorithm instead of single-pole approximation for the energy loss and considering more accurate SE excitation process, a good agreement had been obtained for absolute SE yield (Joy, 1995) and the SE spectrum (Joy et al, 2004) with experimental ones (Fig. 13).…”

“…Comparison on (a) the SE yield and (b) the SE energy spectra between experimental measurements and the calculations for Si. Experimental data are represented by solid symbols in (a) (Joy, 1995) and solid line in (b) (Joy et al, 2004). Shishido et al, 2002;Tanaka et al, 2003).…”

Numerical Modelling of the Electron Backscattering at the Variable Gas Pressure

“…4, concerning the SE initial energy distribution normalized by SE yields (areas under curves are unitary) for Al and Pd, two metals of substantially different densities. The data utilized for these diagrams were taken from [7]. Particular electron energy fractions taken from the diagrams were multiplied by proper values of the extraction coefficients τ e from Fig.…”

Low-Energy Secondary Electron Filtering with Immersion Lens SEM

“…As an example of this effort, this paper will describe the use of energy filtering of the secondary electron (SE) signal using an immersion lens SEM. Applications of this technique include visualizing dopant contrast [2] and improving the sensitivity of passive voltage contrast, Figure 1, as well as the potential for increasing the contrast between key materials of interest by exploiting the different SE energy distributions from different materials (see for example, [3] for experimental measurements of SE spectra).To better understand the complete imaging process Monte-Carlo simulations have been undertaken that include a 3D modeling of the SEM column, including the electromagnetic fields, so that the trajectories of the emitted SE and back-scattered electrons (BSE) from the beam-sample interaction can be accurately followed back into the SEM detection system [4]. Once such a model is in place virtual experiments can be carried to determine the optimum beam and detector conditions for a particular sample type.…”

“…As an example of this effort, this paper will describe the use of energy filtering of the secondary electron (SE) signal using an immersion lens SEM. Applications of this technique include visualizing dopant contrast [2] and improving the sensitivity of passive voltage contrast, Figure 1, as well as the potential for increasing the contrast between key materials of interest by exploiting the different SE energy distributions from different materials (see for example, [3] for experimental measurements of SE spectra).…”