AVS 45th International Symposium
    Surface Science Division Friday Sessions
       Session SS1-FrM

Paper SS1-FrM6
The Strain Effect on Ge-covered Si(001) Surface

Friday, November 6, 1998, 10:00 am, Room 308

Session: Surface Structure and Strain
Presenter: F.-K. Men, National Chung Cheng University, Republic of China
Authors: F.-K. Men, National Chung Cheng University, Republic of China
C.-R. Hsu, National Chung Cheng University, Republic of China
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By loading the free end of a cantilevered bar, we have studied the effect of strain on the Ge-covered Si(001) surface. On this surface, strain produces a reversible change in the relative population of the 2xn and nx2 domains. This change is driven by the relaxation of the energy associated with a long-range strain field extending into the bulk due to the anisotropy of the intrinsic stress tensor of the two reconstructed domains. The dependence of the surface stress anisotropy, defined as the difference of the components of the surface stress tensor parallel and perpendicular to the dimer bond, on the Ge overlayer thickness has been studied. By varying the separation between two neighboring dimer vacancy lines (DVL's) we have investigated the DVL-DVL interaction. Based on a linear-dipole-force model for the step-step interaction and the theory of long-range elastic relaxation of orientationally inequivalent domains, we have estimated the DVL formation energy and the DVL-DVL interaction strength. We have also studied the change in the relative population of the two orthogonal domains as a function of time at different temperatures. Results on the kinetics of the step migration will be presented.