Experimental conditions for surface microanalysis with reflection electron energy-loss spectroscopy.

Experimental conditions for obtaining the optimum signal-to-background (S/B) ratio in reflection electron energy-loss spectroscopy (REELS) are investigated. It is shown that the S/B ratio can be improved by lowering the incident energy of the electrons. The spectra taken from the GaAs (660) specular reflection spot under the surface resonance condition is demonstrated to have the best S/B ratio and lowest surface plasma excitation, which is capable of providing structural information on the top few atomic layers.