Atomic-hydrogen-induced self-organization processes of the In/Si(111) surface phases studied by scanning tunneling microscopy

Abstract

We have investigated the initial processes of the interaction of atomic hydrogen with the 4×1 and the 31 × 31 surface phases in the In/Si(111) system at substrate temperature around 300°C using scanning tunneling microscopy. It has been revealed that the atomic-hydrogen-induced self-organization processes of these surface phases are strongly dependent on the substrate Si reconstruction. The adsorption of atomic hydrogen on the 4×1-In surface, which has a reconstruction of 2 ML of Si layers, involves removal of In atoms from the surface but no Si movement, resulting in the formation of hydrogen-terminated bared zigzagging Si chains with the preservation of the 4×1 periodicity. On the other hand, the adsorption of atomic hydrogen on the 31 × 31 surface, which has a reconstruction of 1 ML of Si layer, exhibits peculiar self-organization processes depending on the hydrogen exposure: at the initial stage of the hydrogen exposure only the half-unit of the 31 × 31 lattice is preferably attacked by hydrogen atoms with the preservation of the 31 × 31 periodicity, while upon prolonged hydrogen exposure, the 31 × 31 periodicity is destroyed as a result of the movement of the Si reconstructed layer, forming hydrogen-terminated quasi-1D Si chains. These results suggest the possibility of atomic-hydrogen-induced self-organization of substrate Si atoms.