Self-assembly of parallel atomic wires and periodic clusters of silicon on a vicinal Si(111) surface

Silicon self-assembly at step edges in the initial stage of homoepitaxial growth on a vicinal Si(111) surface is studied by scanning tunneling microscopy. The resulting atomic structures change dramatically from a parallel array of 0.7 nm wide wires to one-dimensionally aligned periodic clusters of diameter ∼2nm and periodicity 2.7 nm in the very narrow range of growth temperatures between 400 and 300°C. These nanostructures are expected to play important roles in future developments of silicon quantum computers. Mechanisms leading to such distinct structures are discussed.