AVS 54th International Symposium | |
Surface Science | Monday Sessions |
Session SS2-MoM |
Session: | Surface Structure, Growth, and Etching of Silicon and Germanium |
Presenter: | M. Albao, National Sun Yat-Sen University, Taiwan |
Authors: | M. Albao, National Sun Yat-Sen University, Taiwan J.W. Evans, Iowa State University F. Chuang, National Sun Yat-Sen University, Taiwan |
Correspondent: | Click to Email |
A lattice-gas model was developed incorporating a recently observed oxide island shape transformation from linear to two-dimensional1 during initial stages of oxidation of Si(001). Kinetic Monte Carlo (KMC) simulations of such a model offers clues as to the nature of the pinning of steps and their subsequent transformation into finger-like structures2,3 during prolonged etching of vicinal Si(100) by exposure to molecular oxygen. KMC results suggest that the initial linear shape of oxide clusters might allow them to protect slightly wider sections of the steps against erosion than would a similar 2D island of the same number of atoms. This proposal follows from comparison of the width of the "fingers" that subsequently evolved from the pinning by these two cluster types. Thus, the initial shape of the islands as much as their size appears to be key in stabilization and long-term survival of fingers. Additionally, the same model was used to uncover potential mechanisms for boosting oxide cluster nucleation and thus cluster populations at step edges. In turn, this increased concentration of oxide clusters at the steps sets the stage for increased chances of pinning.
1H. Togashi, H. Asaoka, T. Yamazaki, M. Suemitsu, Jpn. J. App. Phys. 44 (2005) 1377.
2J.V. Seiple and J. Pelz, Phys. Rev. Lett. 73 (1994) 999.
3M.A. Albao, D.-J. Liu, M.S. Gordon, and J.W. Evans, Phys. Rev. B 72 (2005) 195420.