AVS 46th International Symposium
    Surface Science Division Thursday Sessions
       Session SS2+EM+NS-ThM

Paper SS2+EM+NS-ThM3
Interdiffusion During Growth of Ge on Si(100)

Thursday, October 28, 1999, 9:00 am, Room 607

Session: Nucleation and Growth
Presenter: H. Jonsson, University of Washington
Authors: H. Jonsson, University of Washington
B.P. Uberuaga, University of Washington
M. Leskovar, University of Washington
B.R. Schroeder, University of Washington
S. Meng, University of Washington
M.A. Olmstead, University of Washington
Correspondent: Click to Email
We present both experimental evidence and a theoretical explanation of sub-monolayer Ge epitaxy on Si(100) interdiffusion to the 4th layer of the Si substrate. XPD measurements at both 500 C and 700 C show the presence of Ge atoms in the 4th layer. DFT/GGA calculations of the energetics of a Ge atom in the Si surface, together with a statistical model of Ge occupation of the lattice sites, predict occupation of sub-surface sites, with enhanced occupation in the sites under tensile strain. The calculations indicate that the formation energy of a Ge interstitial near the surface (about 1 eV higher energy than the adatom) is significantly reduced as compared with an interstitial in bulk Si, thus lowering the energy barrier for the interstitial diffusion mechanism near the surface. This work was supported by the National Science Foundation, the University of Washington Royalty Research Fund and the Japanese New Energy and Technology Development Organization.