Korean Journal of Materials Research (한국재료학회지)

Materials Research Society of Korea (한국재료학회)
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Effect of Post-CMP Cleaning On Electrochemical Characteristics of Cu and Ti in Patterned Wafer

  • Noh, Kyung-Min (Department of Materials Science and Engineering, Korea University) ;
  • Kim, Eun-Kyung (Department of Nano/IT Engineering, Seoul National University of Technology) ;
  • Lee, Yong-Keun (Department of Nano/IT Engineering, Seoul National University of Technology) ;
  • Sung, Yun-Mo (Department of Materials Science and Engineering, Korea University)
  • Published : 2009.03.27
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Abstract

The effects of post-CMP cleaning on the chemical and galvanic corrosion of copper (Cu) and titanium (Ti) were studied in patterned silicon (Si) wafers. First, variation of the corrosion rate was investigated as a function of the concentration of citric acid that was included in both the CMP slurry and the post-CMP solution. The open circuit potential (OCP) of Cu decreased as the citric acid concentration increased. In contrast with Cu, the OCP of titanium (Ti) increased as this concentration increased. The gap in the OCP between Cu and Ti increased as citric acid concentration increased, which increased the galvanic corrosion rate between Cu and Ti. The corrosion rates of Cu showed a linear relationship with the concentrations of citric acid. Second, the effect of Triton X-$100^{(R)}$, a nonionic surfactant, in a post-CMP solution on the electrochemical characteristics of the specimens was also investigated. The OCP of Cu decreased as the surfactant concentration increased. In contrast with Cu, the OCP of Ti increased greatly as this concentration increased. Given that Triton X-$100^{(R)}$ changes its micelle structure according to its concentration in the solution, the corrosion rate of each concentration was tested.

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References

  1. R. Rosenberg, D. C. Edelstein, C. K. Hu and K. P. Rodbell, Annu. Rev. Mater. Sci., 30, 229 (2000) https://doi.org/10.1146/annurev.matsci.30.1.229
  2. J. M. Steigerwald, S. P. Murarka, R. J. Gutmann and D. J. Duquette, Mater. Chem. Phys., 41, 217 (1995) https://doi.org/10.1016/0254-0584(95)01516-7
  3. P. B. Zantye, A. Kumar and A. K. Sikder, Mat. Sci. Eng. R., 45, 89 (2004) https://doi.org/10.1016/j.mser.2004.06.002
  4. F. Zhang, A. A. Busnaina and G. Ahmadi, J. Electrochem. Soc., 146, 2665 (1999) https://doi.org/10.1149/1.1391989
  5. Y. K. Hong, D. H. Eom, S. H. Lee, T. G. Kim, J. G. Park and A. A. Busnaina, J. Electrochem. Soc., 151, G756 (2004) https://doi.org/10.1149/1.1802493
  6. D. Ng, S. Kundu, M. Kulkarni and H. Liang, J. Electrochem. Soc., 155, H64 (2008) https://doi.org/10.1149/1.2806173
  7. S. Kondo, N. Sakuma, Y. Homma and N. Ohashi, Jpn. J. Appl. Phys., 39, 6216 (2000) https://doi.org/10.1143/JJAP.39.6216
  8. P. L. Chen, J. H. Chen, M. S. Tsai, B. T. Dai and C. F. Yeh, Microelectron. Eng., 75, 352 (2004) https://doi.org/10.1016/j.mee.2004.06.006
  9. G. E. Tiller, T. J. Mueller, M. E. Dockter and W. G. Struve, Anal. Biochem., 141, 262 (1984) https://doi.org/10.1016/0003-2697(84)90455-X
  10. A. J. Bard and L. R. Faulkner, Electrochemical Methods: Fundamentals and Applications, 2nd Ed., P. 92, David Harris, John Wiley & Sons, New York, (2001)
  11. D. H. Eom, I. K. Kim, J. H. Han and J. G. Park, J. Electrochem. Soc., 154, D42 (2007)
  12. E. Acosta, M. Bisceglia and D. H. Kurlat, Phys. Chem. Liq., 43, 269 (2005) https://doi.org/10.1080/00319100500066133
  13. P. S. Denkova, L. Van Lokeren, I. Verbruggen and R. Willem, J. Phys. Chem. B., 112, 10935 (2008) https://doi.org/10.1021/jp802830g