Initial stage of Si 111/-B surface reconstruction studied by scanning tunnelling microscopy

Scanning tunnelling microscopy has been used to study the interaction of elemental B with Si 111. 7=7 surface. Elemental B is evaporated at desired temperature room temperature RT., 800–10008C., and the amount of B is varied with the evaporation time. The shapes and structures of the reconstructed areas are only dependent on B coverages. The reconstructed areas which mostly consist of the two types of ring structures bright ring and dark ring.are formed in very small B coverage. When larger amount of B is evaporated, the reconstructed areas containing a mixture of various adatom structures such asʹ3 =ʹ3 R308, 2=2, c 4=2.and the two types of ring structures are formed. These areas grow larger over the surface in proportion to the amount of B until overall of the surface changes to these areas. When much more B is evaporated, the number of the ʹ3 =ʹ3 R308 unit cells increases in these reconstructed surface and well-ordered ʹ3 =ʹ3 R308 surface is formed finally. q1998 Elsevier Science B.V. All rights reserved.