Atomic scale Ph chains on Si(100)

The growth of Pb on Si(100) 2x1 is found by scanning tunneling microscopy t o form one-dimensional ad-dimer chains at a coverage far below a monolayer, analogous to the behavior of group-III elements (Ga, Al, In) on the same s urface but with a buckled dimer configuration. The asymmetric dimerized str ucture is retained for c(8x4) and c(4X4) reconstructions of higher coverage . Tunneling spectra for the Pb dimers exhibit a surface-state band gap of s imilar to1.2 eV and thus suggest a nonmetallic property for the Pb chains, in agreement with the dimerization and buckling feature of Pb atoms. The pa rallel ad-dimer adsorption structure also suggests an approach to obtaining long atomic lines via the selection of the single domain Si(100) as substr ates. (C) 2000 American Vacuum Society. [S0734-211X(00)00505-9].