The design principles of a new, experimental e-beam tester are described. Using the magnetic field of an immersion objective lens the secondary electrons are guided to an energy analyser between the condenser lenses and the objective lens. The latter can now have a short working distance and small aberrations. The electron energies are analysed by a combination trochoidal motion - retarding field analyser, which enables detection of the faster secondary electrons on one detector and detection of the slower secondary electrons on a second detector. The benefit of this set up is a possibility for voltage contrast isolation, normalization with respect to primary beam current and an improved signal to noise ratio in voltage measurements. The use of a variable axis immersion lens allows a large field of view.
Kruit, P. and Dubbeldam, L.
"An Electron Beam Tester with Dispersive Secondary Electron Energy Analyser,"
Scanning Microscopy: Vol. 1
, Article 15.
Available at: https://digitalcommons.usu.edu/microscopy/vol1/iss4/15