GOLD-INDUCED FACETING OF SI(111)

We report an STM investigation of the morphology of Au-covered vicinal Si(111) surfaces. High-resolution STM images of the Si(111)(5 X 2)-Au reconstruction are presented and compared to various structural model s. Depending on coverage, annealing temperature, and inclination angle of the substrate surface we observed the occurrence of two different high-Miller-index Si facets which are stabilized by Au, namely a (2 X 1) reconstructed (775) facet and a (3 X 1) reconstructed (995) facet. A comparison of high-resolution STM images of the facets with images o f the (5 X 2) reconstruction of the (111) terraces indicates that the different structures are closely related.