Classical interatomic potential model for Si/H/Br systems and its application to atomistic Si etching simulation by HBr{sup +}
- Department of Aeronautics and Astronautics, Graduate School of Engineering, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501 (Japan)
An interatomic potential model for Si/H/Br systems has been developed for performing classical molecular dynamics simulations of Si etching processes by HBr plasmas. The potential form used here is the improved Stillinger-Weber potential function involving a correction term in order to predict the reaction dynamics more accurately. Parameters were determined based on ab initio data obtained from previous works on Si/Br systems by [Ohta et al. J. Appl. Phys. 104, 073302 (2008)]. By using this model, we performed Si etching simulations by monoenergetic HBr{sup +} and Br{sup +} beams. H atom has about 1% of the translational energy of cluster ions due to the small H/Br mass ratio (=1.0/79.9); therefore, H atoms in HBr{sup +} behave like H radicals. This results in higher etch yields by HBr{sup +} than those by Br{sup +} in the low-energy region (less than 100 eV). This can be attributed to the chemical enhancement induced by the formation of Si-H bonds. On the other hand, yields by HBr{sup +} and Br{sup +} were almost the same in the high-energy region (more than 100 eV), where physical sputtering was relatively dominant and the contribution of H was small.
- OSTI ID:
- 21185977
- Journal Information:
- Journal of Applied Physics, Vol. 105, Issue 2; Other Information: DOI: 10.1063/1.3056391; (c) 2009 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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