AVS 50th International Symposium
    Surface Science Thursday Sessions
       Session SS1-ThM

Paper SS1-ThM10
Growth of Gd on the High-Index Si(113) and Si(5 5 12) Surfaces

Thursday, November 6, 2003, 11:20 am, Room 310

Session: Patterned Growth and Etching of Semiconductors
Presenter: J.W. Dickinson, Virginia Commonwealth University
Authors: E. Morris, Virginia Commonwealth University
J.W. Dickinson, Virginia Commonwealth University
A.A. Baski, Virginia Commonwealth University
Correspondent: Click to Email
The growth of rare earth metals on the low-index Si(001) surface has been of recent interest due to the appearance of silicide "nanowires."@footnote 1@ This nanowire formation is presumably due to a close lattice match between the rare earth silicide and Si lattice along the [1bar10] row direction, and poor match perpendicular to it. In this study, we have used scanning tunneling microscopy (STM) to examine the growth of the rare earth metal Gd on two high-index Si surfaces: Si(113) and Si(5 5 12). These two surfaces are oriented 25.2° and 30.5° down from (001) towards (111), respectively. When very low coverages of Gd are deposited onto these surfaces and annealed at 600°C, (113) terraces with a well-ordered 2x2 reconstruction are formed. In the case of Si(5 5 12), the reconstructed (113) terraces are opposed by other facet orientations. When the coverage is increased to approximately 0.5 ML, isolated nanowires nucleate at step edges and extend along the [1bar10] direction. These nanowires are 5 to 15 nm wide, 1 to 2 nm tall, and grow up to 0.5 micron in length. Because the lattice periodicity along the nanowire direction is identical for the (001), (113), and (5 5 12) surfaces, the appearance of such nanowires on the high-index surfaces provides further evidence for a lattice mismatch mechanism. Interestingly, the anisotropic structure of these high-index surfaces results in nanowire growth that causes fewer disruptions to the initial step morphology than observed for (001). @FootnoteText@ @footnote 1@ C. Ohbuchi, J. Nogami, Phys. Rev. B 66, 165323 (2002) and references therein.