Scanning tunneling microscopy study of Si growth on a Si(111)root 3x root 3-B surface

Scanning tunneling microscopy is used to study the growth of Si on a Si(111) root 3x root 3-B surface at Si coverages from submonolayer range up to a few monolayers and in an temperature range from 20 to 600 degrees C. Already at room temperature the deposited Si atoms are very mobile on the Si(111) root 3x root 3-B surface. As a result, the amorphous Si islands are formed, leaving the root 3x root 3 reconstruction between islands intact. The dangling bond ''bright'' adatoms of the Si(111) root 3x root 3-B surface were found to be preferential sites for island nucleation. At temperatures of Si(111) epitaxy (greater than or equal to 400 degrees C) Si islands grow amorphously up to a certain critical size and then ''crystallize'' to form epitaxial islands. The structure on top of epitaxial Si islands is always root 3x root 3, which suggests B segregation to the surface. The island shape (random below 600 degrees C) is considered to be governed by the structure and properties of the Si(111) root 3x root 3-B surface.