AVS 49th International Symposium
    Surface Science Wednesday Sessions
       Session SS2-WeA

Paper SS2-WeA8
Growth and O@sub 2@ Reactivity of the Cu/Si(5 5 12) System

Wednesday, November 6, 2002, 4:20 pm, Room C-110

Session: Structure and Chemistry at Metal Surfaces
Presenter: A.A. Baski, Virginia Commonwealth University
Authors: P.H. Woodworth, Virginia Commonwealth University
J.C. Moore, Virginia Commonwealth University
A.A. Baski, Virginia Commonwealth University
Correspondent: Click to Email
Our group has extensively studied the growth behavior of Group IB metals such as Ag and Au on the row-like template provided by the clean Si(5 5 12) surface.@footnote 1@ Here, this work is extended to the remaining IB metal of Cu. Our scanning tunneling microscopy studies show that Cu forms two distinct phases on Si(5 5 12): a lower temperature phase (< 600 °C) where Cu decorates the underlying (5 5 12) surface, and a higher temperature phase (> 600 °C) where it induces faceting to the nearby (113) plane. Similar to the Ag and Au systems, the lower temperature phase results in the formation of Cu "nanowires" with a spacing equal to the 5.4 nm periodicity of the (5 5 12) surface. When the annealing temperature is increased, however, the (5 5 12) orientation is no longer stable to (113) faceting. At lower Cu coverages (< 0.5 ML), (113) planes appear to coexist with (5 5 12), but at higher coverages (> 0.5 ML) these planes form sawtooths with opposing (111) faces. The occurrence of (113) planes has also been seen for the higher temperature growth of Au on Si(5 5 12), indicating the inherent stability of this plane. We have also studied the O@sub 2@ reactivity of the Cu-induced (113)/(111) sawtooths at exposures of 50 to 200 Langmuirs and temperatures of 600 to 800 °C. As expected, an amorphous oxide appears to grow on the surface at lower temperatures (<650 °C), and etching occurs at higher temperatures (>650 °C). For the case of etching, the sawtooths are gradually removed to produce trapezoidal (113)/(111) islands. The density of these islands decreases with increasing temperature, providing a possible route for the controlled fabrication of such nanostructures on the surface.@footnote 1@ A.A. Baski, K.M. Saoud, K.M. Jones, Appl. Surf. Sci. 182, 216 (2001).