Structural analysis of Si(111)-7 x 7 domain boundaries with takayanaki cores

Regular domain boundaries (RDBs) on a Si(111)-7 x 7 surface are investigate d both theoretically and experimentally. Based on the assumption that the R DBs form from a relative shift between two adjacent parts of the perfectly reconstructed lattice, a set of indexes is proposed to classify, the RDBs. The irreducible indexes are obtained according to the constraints derived f rom the lattice-matching condition and the symmetry of the Si(111)-7 x 7 st ructure. Along the RDBs, dimer rows should be constructed serving as backbo nes, and the defects in the RDB should be accompanied by a dimer-adatom sta cking fault subunit or unit spanning the RDB as a matching bridge. Most of the RDBs we obtained by direct annealing of the: Si(111) surface and throug h solid phase growth have such features. The atomic structural models compa red to the STM images of several examples are presented, (C) 2000 American Vacuum Society. [S0734-2101(00)08202-6].