Hallmark of quantum skipping in energy filtered lensless scanning electron microscopy

We simulate the electronic system of ejected electrons arising when a tip, positioned few 10 amp; 8201;nm away from a surface, is operated in the field emission regime. We find that, by repeated quantum reflections quantum skipping , electrons produced at the nanoscale primary site are able to reach the macroscopic environment surrounding the tip surface region. We observe the hallmark of quantum skipping in an energy filtered experiment that detects the spin of the ejected electron

Identification of artefacts in Auger electron spectroscopy due to surface topography

The application of Auger electron spectroscopy to sharp topographies, such as microfabricated field emitters, leads to two analysis artifacts; edge enhancement and shadowing. As a result, the detected Auger electron peak heights can change by more than 100%; potentially giving rise to the wrong conclusions being drawn about the elemental surface concentrations. A single-pass cylindrical mirror analyzer has been modified for use in the rapid identification of such artifacts. The modifications comprises a multichannel electron detector divided into six segments spanning 360° of azimuth and an electrostatic lens that passes electrons to the electron detector along the same exit trajectory independently of their energy. Preliminary results of the use of the instrument in the analysis of a tungsten coated volcano-shaped silicon field-emitter structure are reported. The analysis simultaneously shows two different edge artifacts in the six spectra due to edge enhancement and shadowing. The experiment demonstrated here shows a rapid method for identifying these artifacts and avoids the need to repeat the experiment using a different angle of incidence, as was conventionally the case

Very-low-energy electron microscopy of doped semiconductors

Imaging of As- and B-doped silicon regions has been performed in a scanning electron microscope operated in the cathode lens mode, with incident electron energies (EP) as low as 15 eV. The doped regions of n+ (As, 2.5×1020 cm–3) and p+ (B, 8×1019 cm–3) on n-type silicon (~1015 cm–3) show distinct contrast with electron energies of about 3 keV. The brightest region is n+ followed by p+, then the n-type substrate. The highest contrast for the p+ and n+ type regions is reached at about EP = 300 and 15 eV, respectively. The contrast mechanisms are explained in terms of metal-semiconductor contact assuming an adventitious carbon film at the surface