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http://dx.doi.org/10.3740/MRSK.2010.20.11.617

Effect of Saw-Damage Etching Conditions on Flexural Strength in Si Wafers for Silicon Solar Cells  

Kang, Byung-Jun (Department of Materials Science and Engineering, Korea University)
Park, Sung-Eun (Department of Materials Science and Engineering, Korea University)
Lee, Seung-Hun (Department of Materials Science and Engineering, Korea University)
Kim, Hyun-Ho (Department of Materials Science and Engineering, Korea University)
Shin, Bong-Gul (Department of Materials Science and Engineering, Seoul National University of Technology)
Kwon, Soon-Woo (R&D Center, TS Corporation)
Byeon, Jai-Won (Department of Materials Science and Engineering, Seoul National University of Technology)
Yoon, Se-Wang (R&D Center, TS Corporation)
Kim, Dong-Hwan (Department of Materials Science and Engineering, Korea University)
Publication Information
Korean Journal of Materials Research / v.20, no.11, 2010 , pp. 617-622 More about this Journal
Abstract
We have studied methods to save Si source during the fabrication process of crystalline Si solar cells. One way is to use a thin silicon wafer substrate. As the thickness of the wafers is reduced, mechanical fractures of the substrate increase with the mechanical handling of the thin wafers. It is expected that the mechanical fractures lead to a dropping of yield in the solar cell process. In this study, the mechanical properties of 220-micrometer-solar grade Cz p-type monocrystalline Si wafers were investigated by varying saw-damage etching conditions in order to improve the flexural strength of ultra-thin monocrystalline Si solar cells. Potassium hydroxide (KOH) solution and tetramethyl ammonium hydroxide (TMAH) solution were used as etching solutions. Etching processes were operated with a varying of the ratio of KOH and TMAH solutions in different temperature conditions. After saw-damage etching, wafers were cleaned with a modified RCA cleaning method for ten minutes. Each sample was divided into 42 pieces using an automatic dicing saw machine. The surface morphologies were investigated by scanning electron microscopy and 3D optical microscopy. The thickness distribution was measured by micrometer. The strength distribution was measured with a 4-point-bending tester. As a result, TMAH solution at $90^{\circ}C$ showed the best performance for flexural strength.
Keywords
solar cell; ultra-thin silicon wafer; saw damage etching; flexural strength;
Citations & Related Records
Times Cited By KSCI : 2  (Citation Analysis)
Times Cited By SCOPUS : 1
연도 인용수 순위
1 R. M. Swanson, Prog. Photovolt. Res. Appl., 14, 443 (2006).   DOI   ScienceOn
2 R. Mertens, in Proceedings of the International Symposium on the Physical and Failure Analysis of Integrated Circuits (Singapore, July, 2008), p. 1-5.
3 K. A. Munzer, K. T. Holdermann, R. E. Schlosser and S. Sterk, IEEE Trans. Electron Dev., 46(10), 2055 (1999).   DOI   ScienceOn
4 J. S. Lee, S. Kwon, H. Park, Y. D. Kim, H. Kim, H. Lim, S. Yoon and D. Kim, Kor. J. Mater. Res., 19(1), 18 (2009) (in Korean).   DOI   ScienceOn
5 L. D. Partain, Solar Cells and Their Applications, p. 60, John Willey & Sons, NJ, USA (1995).
6 S. Kwon, J. Yi, S. Yoon and D. Kim, J. KSNRE, 5(1), 26 (2009) (in Korean). ISSN : 1738-3935.
7 Korean Industrial Standard, KS L 1591, Fine ceramics (advanced ceramics, advanced technical ceramics)-Test method for flexural strength of monolithic ceramics at room temperature, p. 1-13, Agency for Technology and Standards, Ministry of Knowledge Economy, (2008).