Scanning tunneling microscopy has been used to investigate the site of domain boundary on Si (111) 7×7. Within a 0.4μm×0.4μm area, six domain boundaries are observed, and all of them are located at the terraces constricted by zig-zag steps. From the step configuration, the observed surface is defined as a vicinal (111) misoriented by 0.40°towards [101]. Discussion is focused on the shape of the vicinal (111) surface and the effect of the domain boundary on the step configuration.
