L. Frank et al., The scanning low-energy electron microscope: First attainment of diffraction contrast in the scanning electron microscope, SCANNING, 21(1), 1999, pp. 1-13
Using small Pb crystals deposited in situ on a partially contaminated Si (1
00) crystal, we demonstrate that a commercial scanning electron microscope
(SEM) can easily be converted into a scanning low-energy electron microscop
e (SLEEM). Although the contrast mechanism is much more complicated them th
at in nonscanning LEEM because not only one diffracted monochromatic beam a
nd its close environment are used for imaging, but several diffracted beams
and a wide energy spectrum of electrons of different origin (secondary ele
ctrons, inelastically and elastically scattered electrons) are used, SLEEM
is a valuable addition to the standard SEM because it provides an additiona
l structure- and orientation-sensitive contrast mechanism in crystalline ma
terials, a low sampling depth, and high intensity at low energies.