AVS 45th International Symposium
    Surface Science Division Tuesday Sessions
       Session SS1-TuM

Paper SS1-TuM1
Effect of Tensile Strain on B-type Step Energy on Si(001)-(2x1) Surfaces Determined by Switch-Kink Counting

Tuesday, November 3, 1998, 8:20 am, Room 308

Session: Semiconductor Surface Structure
Presenter: E. Heller, Ohio State University
Authors: E. Heller, Ohio State University
J.P. Pelz, Ohio State University
D.E. Jones, Company
Y.H. Xie, Company
P.J. Silverman, Company
Correspondent: Click to Email
Several years ago Xie et al.@footnote 1@ suggested that applied strain could strongly influence the creation energy of so-called S@sub B@ steps on Si(001)-(2x1) surfaces, which could dramatically affect surface roughening during strain-layer growth. Swarzentruber et al.@footnote 2@ and then later Zandvliet et al.@footnote 3@ showed that step energies on unstrained Si(001)-(2x1) surfaces could be estimated by counting kinks (a kink being a small perpendicular jump in a surface step edge) on samples annealed at elevated temperatures. In order to directly test the proposal of Xie et al., we have used kink-counting in STM images of strained Si(001) surfaces to quantify the effect of strain of the S@sub B@ step energy. For this purpose, we have developed a new kink-counting method (called switch-kink counting), which is more accurate than previous methods when the azimuthal miscut angle changes across the surface. This can be problematic when there is macroscopic surface roughness, due to cross-hatch or imperfect surface preparation. I will describe both the method used by Zandvliet et al. and our new method as well as why it is more accurate for non-constant azimuthal miscut angle. I will then give an analysis of data using both of these methods on a large data set we have collected from STM images. We find an energy for these kinks that is significantly higher than that found by Zandvliet et al. for unstrained silicon, and appears to increase with increasing tensile strain, although possibly not as fast as Xie et al. predict. @FootnoteText@ @footnote 1@Xie et al., Phys. Rev. Lett. 73, 3006 (1994). @footnote 2@B. S. Swartzentruber, Y.-W. Mo, R. Kariotis, M. G. Lagally, and M. B. Webb, Phys. Rev. Lett. 65, 1913 (1990). @footnote 3@H. J. W. Zandvliet, H. B. Elswijk, E. J. van Loenen, and D. Dijkkamp, Phys. Rev. B, 45, 5965 (1992).