Classical interatomic potential model for Si/H/Br systems and its application to atomistic Si etching simulation by HBr{sup +}

Journal Article · Thu Jan 15 04:00:00 EST 2009 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3056391· OSTI ID:21185977

Nagaoka, T; Eriguchi, K; Ono, K; Ohta, H ^[1]

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1. 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, Journal Name: Journal of Applied Physics Journal Issue: 2 Vol. 105; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BROMINE IONS
ETCHING
EV RANGE 10-100
EV RANGE 100-1000
HYDROBROMIC ACID
HYDROGEN
INTERATOMIC FORCES
ION BEAMS
ION PAIRS
MOLECULAR DYNAMICS METHOD
POTENTIALS
RADICALS
SEMICONDUCTOR MATERIALS
SILICON
SIMULATION
SPUTTERING