Journal of the Korean Physical Society

pISSN 0374-4884 eISSN 1976-8524


Condensed Matter

J. Korean Phy. Soc. 2006; 49(1): 167

Published online July 15, 2006

Copyright © The Korean Physical Society.

One-Dimensional Ordered Structure of C2H4 on a Si(001) Surface

J. H. Seo, J. Y. Park, C. N. Whang, K.-H. Yoo, S. S. Kim, D. S. Choi and K. H. Chae


A one-dimensional (1-D) ordered structure of ethylene (C$_{2}$H$_{4}$) molecules on a Si(001) surface has been investigated by using coaxial impact collision ion scattering spectroscopy (CAICISS) and computer simulations. In a previous paper, the di-$sigma$ on-top site of the Si(001)-(2 $ imes$ 1) surface was exposed at room temperature (RT) to 100L (1L $=$ 10$^{-6}$ Torr$% cdot $sec)of C$_{2}$H$_{4}$ molecules, which were intially absorbed on that surface. With increasing number of C$_{2}$H$_{4}$ molecules, a structural change of C$_{2}$H$_{4}$/Si(001)-(2 $ imes$ 1) surface was observed by using the low-energy electron diffraction (LEED). When the Si(001)-(2 $ imes$ 1) surface at RT to 200L of C$_{2}$H$_{4}$ molecules, the C$_{2}$H$_{4}$ molecules occupied the di-$sigma$ on-top site on the Si(001)-(2 $ imes$ 1) surface. With the help of a computer simulation, the C--C and Si--C bond lengths were found to be $1.61~pm~0.05$ AA and $1.81~pm~0.05$ AA , respectively. The C$_{2}$H$_{4}$ molecules were also found to be adsorbed on the Si(001) surface on in tandem along the direction of Si dimer-rows. This result provides evidence supporting the mechanism of 1-D nano-structure formation based on the C$_{2}$H$_{4}$ molecules on Si(001) surface.vspace{-0.2cm}