Location of adatoms on Si(100) surface using the electron channeling effect on Auger electron emission

Abstract

Atomic-site location by channeling enhanced microanalysis (ALCHEMI) is a powerful technique for identifying both the atomic number and the location of impurity atoms in crystals. The principle of the technique is simple: electron intensities on particular crystallographic sites within unit cell oscillate with variation of the incident beam direction. The corresponding characteristic emission spectra from atoms at those atomic sites follow these oscillations if the inelastic scattering events are localized. By careful analyzing the spectra of the impurity species and those of the reference atoms on known sites at various tilting angles, the location of the impurity atoms can be obtained. However, most applications of this technique have used the channeling effect on characteristic x-ray emission or energy loss spectra for location of impurity atoms in bulk crystals Here we study the possibility of applying this technique for locating adatom positions on a crystal surface, using the channeling effect on characteristic Auger emissions.