Step characterization on vicinal Si surfaces by reflection high-energy electron diffraction at arbitrary azimuths

Based on kinematic theory, we demonstrate the reflection high-energy electron diffraction RHEED.characterization of the step period on vicinal Si surfaces from the separation of the specular beam split spots at an arbitrary azimuth. Increasing the azimuthal angle between the electron beam and the step direction enlarges the separation between the split spots and thus enables the split spot separation discernible even at large step periods. Vicinal Si 001.surfaces with miscuts ranging from 0.328 nearly flat.up to 108 as well as a Si 113. surface with step periods up to about 100 nm have been successfully analyzed. It is found that a well prepared vicinal Si 001.surface always shows a double-layer period by RHEED. q1999 Elsevier Science B.V. All rights reserved.