Electron energy loss spectrometry scanning

Once the breakdown location is identified using DBIE, electron energy loss spectrometry (EELS) was performed using a FEI-TITAN 300 kV TEM/STEM to analyze the chemical nature of the percolation path [10,11]. Fig. 2 illustrates a close-up view of the sample configuration and beam-sample interaction. STEM/EELS spectra were collected at 80 keV beam voltage using point-to-point vertical and horizontal scans as shown in Fig. 2b across the dielectric layer at the breakdown site identified by a DBIE and at the non-breakdown site that were far away from the DBIE. 

This article will focus on the use of electron energy loss spectrometry (EELS) in a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM). In a TEM or STEM, a beam of electrons is accelerated to energies typically between 100 keV and IMeV. The beam of electrons is transmitted through a sample that consists of a thin piece of material (typically less than 50 nm thickness). Interaction of the beam with the sample enables the operator to learn something about the sample, such as the chemical elements present, stoichiometry, energy levels, electronic structure, and more. 

Fig. 1. Experimental techniques available for surface studies. SEM = Scanning electron microscopy (all modes) AES = Auger electron spectroscopy LEED = low energy electron diffraction RHEED = reflection high energy electron diffraction ESD = electron stimulated desorption X(U)PS = X-ray (UV) photoelectron spectroscopy ELS = electron loss spectroscopy RBS = Rutherford back scattering LEIS = low energy ion scattering SIMS = secondary ion mass spectrometry INS = ion neutralization spectroscopy.

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