Microstructures Formation by Fluorocarbon Barrel Plasma Etching

El amrani, A.; Tadjine, R.; Moussa, F. Y.

doi:https://doi.org/10.1155/2008/371812

International Journal of Plasma Science and Engineering

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Research Article | Open Access

Volume 2008 | Article ID 371812 | https://doi.org/10.1155/2008/371812

Microstructures Formation by Fluorocarbon Barrel Plasma Etching

A. El amrani,¹R. Tadjine,²and F. Y. Moussa¹

Academic Editor: Rami A. Kishek

Received27 Mar 2007

Revised07 Aug 2007

Accepted17 Sept 2007

Published21 Nov 2007

Abstract

The aim of our study is to generate microstructures in order to improve optical properties of monocrystalline silicon. By mean of fluorocarbon plasma barrel texturing and under certain process conditions, silicon turned black. As a result of silicon surface-plasma particles reactions, porous microstructures are formed, while a longer process time microspikes are developed. These microstructures are responsible of the high level of light trapping on almost the whole range of the usable portion of the solar spectrum. In the wavelength range of 400–1100 nm, the AM1.5G weighted reflection has been reduced to 6.20%. In addition to good trapping, this surface morphology leads to superior absorption, which is about 95% in the 600–1000 nm range and decreases to 36% at 1200 nm. This material is thus less transparent and absorbs near infrared light far more than the untreated silicon. Secondary ion mass spectrometry shows that elements from the ambient gas are deposited or superficially introduced into the silicon. In addition to surface texturing, these impurities are probably the reason of absorptance enhancement. Moreover, a pore formation mechanism is proposed.

References

A. R. Burgers, R. Kinderman, J. D. Hylton, W. C. Sinke, and H. H. C. de Moor, “Light-trapping in saw-damage etched silicon wafers,” in Proceedings of the 14th European Photovoltaic Solar Energy Conference Exhibition (EPVSEC '97), pp. 143–145, Barcelona, Spain, June-July 1997.
View at: Google Scholar
D. S. Ruby, S. H. Zaidi, and S. Narayanan, “Plasma-texturization for multicrystalline silicon solar cells,” in Proceedings of the 28th IEEE Photovoltaic Specialists Conference (PVSC '00), pp. 75–78, Anchorage, Alaska, USA, September 2000.
View at: Publisher Site | Google Scholar
C. Wu, C. H. Crouch, and L. Zhao et al., “Near-unity below-band-gap absorption by microstructured silicon,” Applied Physics Letters, vol. 78, no. 13, pp. 1850–1852, 2001.
View at: Publisher Site | Google Scholar
J. D. Hylton, A. R. Burgers, and W. C. Sinke, “Alkaline etching for reflectance reduction in multicrystalline silicon solar cells,” Journal of the Electrochemical Society, vol. 151, no. 6, pp. G408–G427, 2004.
View at: Publisher Site | Google Scholar
J. W. Müller, A. Metz, and R. Hezel, “A new and simple approach for fabricating inverted pyramids on crystalline silicon solar cells,” in Proceedings of the 17th European Photovoltaic Solar Energy Conference and Exhibition (EUPVSEC '01), Munich, Germany, October 2001.
View at: Google Scholar
P. Panek, “Effect of macroporous silicon layer on opto-electrical parameters of multicrystalline silicon solar cell,” Opto-Electronics Review, vol. 12, no. 1, pp. 45–48, 2004.
View at: Google Scholar
S. W. Park, J. Kim, and S. H. Lee, “Application of acid texturing to multi-crystalline silicon wafers,” Journal of the Korean Physical Society, vol. 43, no. 3, pp. 423–426, 2003.
View at: Google Scholar
S. Lust, C. Lévy-Clément, and C. Vard et al., “First multicrystalline si solar cells with electrochemical macroporus texturization,” in Proceedings of the 17th European Photovoltaic Solar Energy Conference and Exhibition (EUPVSEC '01), pp. 1436–1439, Munich, Germany, October 2001.
View at: Google Scholar
R. Younkin, J. E. Carey, E. Mazur, J. A. Levinson, and C. M. Friend, “Infrared absorption by conical silicon microstructures made in a variety of background gases using femtosecond-laser pulses,” Journal of Applied Physics, vol. 93, no. 5, pp. 2626–2629, 2003.
View at: Publisher Site | Google Scholar
W. Jooß, “Multicrystalline and back contact buried contact silicon solar cells,” Doctor of the natural sciences thesis, University of Konstanz, Konstanz, Germany, July 2002.
View at: Google Scholar
A. Schneider, T. Pernau, K. Peter, and P. Fath, “Mechanical wafer stability enhancements and texturing effects of remote downstream plasma etching,” in Proceedings of the 3rd World Conference on Photovoltaic Energy Conversion (WCPEC '03), vol. 2, pp. 1419–1422, Osaka, Japan, May 2003.
View at: Publisher Site | Google Scholar
G. Kumaravelu, M. M. Alkaisi, and A. Bittar, “Surface texturing for silicon solar cells using reactive ion etching technique,” in Proceedings of the 29th IEEE Photovoltaic Specialists Conference (PVSC '02), pp. 258–261, New Orleans, La, USA, May 2002.
View at: Google Scholar
H. Jansen, M. de Boer, R. Legtenberg, and M. Elwenspoek, “Black silicon method: a universal method for determining the parameter setting of a fluorine-based reactive ion etcher in deep silicon trench etching with profile control,” Journal of Micromechanics and Microengineering, vol. 5, no. 2, pp. 115–120, 1995.
View at: Publisher Site | Google Scholar
K. Takahashi, M. Hori, and T. Goto, “Fluorocarbon radicals and surface reactions in fluorocarbon high density etching plasma. I. $O_{2}$ addition to electron cyclotron resonance plasma employing ${CHF}_{3}$ ,” Journal of Vacuum Science and Technology A, vol. 14, no. 4, pp. 2011–2019, 1996.
View at: Publisher Site | Google Scholar
Z. He and K. T. Leung, “Vibrational electron energy loss studies of surface processes on Si(111) $7 \times 7$ and vitreous ${Sio}_{2}$ ion-mediated in ${CF}_{4}$ and ${CH}_{2} F_{2}$ ,” Surface Science, vol. 523, no. 1-2, pp. 48–58, 2003.
View at: Publisher Site | Google Scholar
J. Bhardwaj, H. Ashraf, and A. McGuarrie, “Dry silicon etching for MEMS,” in Proceedings of the Meeting of the Electrochemical Society, Microstructures and Microfabricated Systems III Symposium, vol. 97-5, pp. 118–130, Montreal, Quebec, Canada, May 1997.
View at: Google Scholar
R. A. Morgan, Plasma Etching in Semiconductor Fabrication, vol. 1, Elsevier, Amsterdam, The Netherlands, 1985.
View at: Google Scholar

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Copyright © 2008 A. El amrani et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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