Observation of Si(111) Surfaces Using Energy-analyzed Electrons.

Abstract

A stepped Si(111) surface consisted of atomically flat terraces and step bands where atomic steps bunched was prepared by direct-current heating in UHV. An electron-emission spectrum, generated with a field-emission-type electron gun, was observed in situ with a scanning Auger microscope (SAM). The electron-emission spectrum obtained in the direct mode included only characteristic Auger electron (AE) peaks of silicon and a secondary-electron (SE) peak. The AE/SE spectrum obtained from the atomically flat Si(111) terrace between the steps was different from the spectra from sputtered clean silicon (111) and (100) surfaces as to the background shape and the relative intensities of the characteristic peaks. We also found that the stepped surface morphology could be imaged by using only the energy-analyzed SEs when the intensity was defined as the difference between the peak height and the background intensity.