title: Two-dimensional carbon incorporation into Si(001): C amount and structure of Si(001)-c(4 x 4).
abstract: The C amount and the structure of the Si(001)-c(4 x 4) surface is studied using scanning tunneling microscopy (STM) and ab initio calculations. The c(4 x 4) phase is found to contain 1/8 monolayer C (1 C atom in each primitive unit cell). From the C amount and the symmetry of high-resolution STM images, it is inferred that the C atoms substitute the fourth-layer site below the dimer row. We construct a structure model relying on ab initio energetics and STM simulations. Each C atom induces an on-site dimer vacancy and two adjacent rotated dimers on the same dimer row. The c(4 x 4) phase constitutes the subsurface Si(0.875)C(0.125) delta layer with two-dimensionally ordered C atoms.
authors.affiliation: Korea Research Institute of Standards and Science, P.O. Box 102, Yuseong, Daejeon 305-600, Korea.
authors.forename: Hanchul
authors.initials: H
authors.lastname: Kim
authors.forename: Wondong
authors.initials: W
authors.lastname: Kim
authors.forename: Geunseop
authors.initials: G
authors.lastname: Lee
authors.forename: Ja-Yong
authors.initials: JY
authors.lastname: Koo