Hostname: page-component-78c5997874-mlc7c Total loading time: 0 Render date: 2024-11-19T08:35:44.855Z Has data issue: false hasContentIssue false
  • English
  • Français

Role of Phosphoric Acid in Copper Electrochemical Mechanical Planarization Slurries

Published online by Cambridge University Press:  31 January 2011

Serdar Aksu
Serdar Aksu*
Affiliation:
ser_aksu@yahoo.comsaksu@solopower.com, SoloPower, Inc., R&D, 5981 Optical Court, San Jose, California, 95138, United States, 408-966 5459, 408-934 1500
Get access

Abstract

In this paper, the electrochemical behavior of copper in aqueous solutions containing phosphoric acid (H3PO4) is investigated to elucidate the role of H3PO4 in the Cu ECMP slurries. Aqueous solubility and potential-pH diagrams were constructed for copper-phosphate-water system. Good correlations were found between the diagrams and the experimental polarization data. It was found that H3PO4 might not able to sufficiently increase the solubility of copper alone. A complexing agent is needed to ensure the high solubility of copper, especially as the slurry pH and dissolved copper concentration increase. Specific conductance measurements revealed that phosphoric acid was the key constituent responsible for increasing the conductivity of the ECMP electrolyte. In situ electrochemical polarization experiments showed that the planarization mechanism during the ECMP process was similar to that observed in conventional copper CMP.

Keywords

CuCMPslurry
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 1157: Symposium E – Science and Technology of Chemical Mechanical Planarization (CMP) , 2009 , 1157-E12-03
Copyright
Copyright © Materials Research Society 2009

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1 Chen, K. W., Wang, Y. L., Liu, C. P., Chang, L., Li, F. Y., Thin Solid Films, 498, 50 (2006).Google Scholar
2 Hong, Y., Roy, D., Babu, S. V., Electrochem. Solid-State Lett., 8, G297 (2005).Google Scholar
3 Tripathi, A., Burkhard, C., Suni, II., Li, Y., Doniat, F., Barajas, A., and McAndrew, J., J. Electrochem. Soc, 155, H918 (2008).Google Scholar
4 West, A. C., Shao, I., Deligianni, H., J. Electrochem. Soc., 152, C652 (2005).Google Scholar
5 Aksu, S., Emesh, I., Uzoh, C. and Basol, B., ECS Trans. 2, 417 (2006).Google Scholar
6 Liu, F. Q., Tsai, S. D., Hu, Y., Neo, S. S., Wang, Y., Duboust, A., Chen, L-Y, US Patent No. 7,128,825 (October 31, 2006).Google Scholar
7 Wang, M. T., Tsai, M. S., Liu, C., Tseng, W. T., Chang, T. C., Chen, L. J., Chen, M. C., Thin Solid Films 308, 518 (1997).Google Scholar
8 Lee, J-W., Kang, M-C, Kim, J. J., J. Electrochem. Soc, 152, C827 (2005).Google Scholar
9 Shattuck, K. G., Lin, J-Y, Cojocaru, P., West, A. C., Electrochim. Acta, 53, 8211 (2008).Google Scholar
10 Smith, R. M. and Martell, A. E., NIST Critically Selected Stability Constants of Metal Complexes Database Software, Version 8.0, May 2004.Google Scholar
11 Ball, J. W. and Nordstrom, D. K., WATEQ4F Database, U. S. Geological Survey, Menlo Park, California (1991).Google Scholar
12 Tamilmani, S., Huang, W., Raghavan, S., and Small, R., J. Electrochem. Soc., 149, G638 (2002).Google Scholar
13 Aksu, S. and Doyle, F. M., J. Electrochem. Soc., 149, G352 (2002).Google Scholar