AVS 45th International Symposium
    Surface Science Division Thursday Sessions
       Session SS1+NS-ThM

Paper SS1+NS-ThM6
The Atomistics of Homoepitaxial Growth on bcc(110)-Surfaces

Thursday, November 5, 1998, 10:00 am, Room 308

Session: Growth and Thin Films
Presenter: U.K. Koehler, Ruhr-Universitaet Bochum, Germany
Authors: U.K. Koehler, Ruhr-Universitaet Bochum, Germany
C. Jensen, Ruhr-Universitaet Bochum, Germany
A. v. Stockhausen, Ruhr-Universitaet Bochum, Germany
Correspondent: Click to Email
Time lapsed STM-movies, which allow a direct observation of the kinetics of growth processes on an atomic level up to 500°C, SPA-LEED and Monte-Carlo simulations are used to study the nucleation and growth behavior of homoepitaxy on the bcc(110)-surface. For Fe on Fe(110) and W on W(110) a strongly anisotropic growth with islands elongated in [001]-direction is found. A very effective Schwoebel-barrier leads to a nearly perfect statistical growth at RT with increasing island anisotropy in upper layers. At higher coverage a complete facetting of the surface is found and analyzed with SPA-LEED. A quantitative analysis of the STM-movies together with a kinetic Monte-Carlo simulation, which includes the full crystallographic symmetry of the bcc(110)surface, is used to extract information on the atomic diffusion behavior governing growth. A variety of growth features like the rugged appearance of the island edges and changes in the island shape with temperature are correctly reproduced in the simulation and can be assigned to the local diffusion energetics at step edges. Especially an anisotropic diffusion, which strongly suppresses diffusion along [001], is needed to reproduce the observed island anisotropies. A comparison of the layer distribution in the simulation with the one found with STM is used to determine the Schwoebel-barrier. Lateral island coarsening and an atom flux across the step edge following a temperature increase after growth is directly observed in STM.