Improving the Detection and the Analysis of Energy Filtered and Spin Polarised Electrons with the implementation of a Miniature Energy Analyser

Abstract

With the aim of improving detection and analysis of energy filtered electrons in the Scanning Field-Emission Microscope (SFEM) and of the spin polarised electrons in the SFEM with Polarisation Analysis (SFEMPA) tests are performed on a miniature electron detection unit employing a Bessel Box energy analyser. Even in conventional electron microscopes, the detection of low-energy electrons (with kinetic energies of the order of 100eV or lower) is inherently difficult due to the presence of electrostatic (and magnetic) fields in proximity of the beam-target interaction region, inhibiting the escape of these electrons and complicating the interpretation of their detected signal. The reduced dimensions of such a compact energy analyser - with a length of 1&1/2 channeltrons - consent its employment close to the sample surface, thus minimising the aforementioned fields effects. Experimental results demonstrating the capability of this analyser to collect electron spectra are discussed.