S step growth mechanism on the reconstructed 001/surfaces of B diamond structure crystals

The SB step growth mechanism on 001.surfaces of diamond structure crystals was elucidated precisely. This SB step growth occurs as the following process: q2C q2C SBstep type I ª SBstep type IIªSB step type I with a missing dimer ª SB step type I The process of filling the missing dimer at the SB step type I edge was investigated in detail by using quantum chemical calculation. Because the SB step type I has a diene structure, two stable positions are available for migrating adatoms at the edge of the SB step type I. When two adatoms occupy the two stable positions, a dimer cluster is formed and migrates to fill the missing dimer and a normal SB step type I structure is reproduced. Since the potential energy barriers appearing in the processes of a single adatom and the subsequent cluster migrations at the SB step type I with a missing dimer are lower than that which appeared in the single adatom migration process along the dimer rows on terraces of 001.surfaces, the filling of the missing dimer occurs easily in the SB step growth. q1998 Elsevier Science B.V. All rights reserved.