Abstract
The evolution of sidewall roughness (SWR) during reactive ion etching (RIE) was simulated using a Monte Carlo method. It was discovered that the sidewall roughness established during an earlier etch period represents a historical archive of the moment during which the etch front passes by and is not affected by further etching. We also found that the behavior of SWR follows two distinct trends. At the initial stages, SWR increases with etch time, or its equivalent, the etch depth, but, beyond a certain etch depth, SWR of etched surfaces stabilizes and does not change with further etching. This is related to the change of the number of shadowing and reemitted particles as the etch depth increases. When the shadowing sticking coefficient decreases significantly, SWR increases beyond a certain critical depth due to reemission. Additionally, the noise also increases as the sticking coefficient decreases because of an increased number of reemitted particles. The simulated results support very well the assertions and mechanisms of the experimental findings and an etch model based on shadowing and first-order reemission effects at low RIE pressure.
Similar content being viewed by others
References
Y. Zhao, F. Wang, Z.C. Cui, J. Zheng, H.M. Zhang, D.M. Zhang, S.Y. Liu, M.B. Yi, Microelectron. J. 35, 605 (2004)
S.K. Pani, C.C. Wong, K. Sudharsanam, S.G. Mhaisalkar, V. Lim, S. Mohanraj, P.V. Ramana, Thin Solid Films 462–463, 471 (2004)
S.K. Pani, C.C. Wong, K. Sudharsanam, Appl. Phys. Lett. 85, 1295 (2004)
S.K. Pani, C.C. Wong, K. Sudharsanam, C.S. Premachandran, M.K. Iyer, J. Vac. Sci. Technol. 24, 163 (2006)
S.K. Pani, C.C. Wong, K. Sudharsanam, V. Lim, Appl. Surf. Sci. 239, 445 (2005)
K.K. Lee, D.R. Lim, H. Luan, A. Agarwal, J. Foresi, L.C. Kimerling, Appl. Phys. Lett. 77, 1617 (2000)
F. Family, T. Vicsek (eds.), Dynamics of Fractal Surfaces (World Scientific, Singapore, 1991)
Y.P. Zhao, T.M. Lu, G.C. Wang, Measurement of Surface Roughness (Academic, New York, 2000)
N. Agarwal, S. Ponoth, J. Plawsky, P.D. Persans, Appl. Phys. Lett. 78, 2294 (2001)
N. Agarwal, S. Ponoth, J. Plawsky, P.D. Persans, J. Vac. Sci. Technol. A 20, 1587 (2002)
J.H. Yao, H. Guo, Phys. Rev. E 47, 1007 (1993)
J.T. Drotar, Y.-P. Zhao, T.-M. Lu, G.-C. Wang, Phys. Rev. B 62, 2118 (2000)
Author information
Authors and Affiliations
Corresponding author
Additional information
PACS
52.65.Pp; 52.77.Bn; 81.65.Cf
Rights and permissions
About this article
Cite this article
Pani, S., Tjiptoharsono, F., Wong, C. et al. Monte Carlo simulation studies of sidewall roughening during reactive ion etching. Appl. Phys. A 88, 401–407 (2007). https://doi.org/10.1007/s00339-007-3997-6
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00339-007-3997-6