Interplay between elastic interactions and kinetic processes in stepped Si (001) homoepitaxy
- Harvard University
- ORNL
A vicinal Si (001) surface may form stripes of terraces, separated by monatomic-layer-high steps of two kinds, S-A and S-B. As adatoms diffuse on the terraces and attach to or detach from the steps, the steps move. In equilibrium, the steps are equally spaced due to elastic interaction. During deposition, however, S-A is less mobile than S-B. We model the interplay between the elastic and kinetic effects that drives step motion, and show that during homoepitaxy all the steps may move in a steady state, such that alternating terraces have time-independent, but unequal, widths. The ratio between the widths of neighboring terraces is tunable by the deposition flux and substrate temperature. We study the stability of the steady-state mode of growth using both linear perturbation analysis and numerical simulations. We elucidate the delicate roles played by the standard Ehrlich-Schwoebel (ES) barriers and inverse ES barriers in influencing growth stability in the complex system containing (S-A+S-B) step pairs.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- DE-AC05-00OR22725
- OSTI ID:
- 931902
- Journal Information:
- Physical Review B, Vol. 74, Issue 23
- Country of Publication:
- United States
- Language:
- English
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