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Optimization of Material Removal Efficiency in Low Pressure CMP

Published online by Cambridge University Press:  31 January 2011

Dinçer Bozkaya  and
Sinan Müftü
Dinçer Bozkaya
Affiliation:
bozkaya@coe.neu.edu, Northeastern University, Mechanical Engineering, Boston, Massachusetts, United States
Sinan Müftü
Affiliation:
smuftu@coe.neu.edu, Northeastern University, Mechanical Engineering, 334 SN, Department of Mechanical & Industrial Engineering, 334 SN, Boston, Massachusetts, 02115, United States, 6173734743
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Abstract

In chemical-mechanical polishing (CMP) the material removal efficiency (MRE) can be defined as the fraction of the total pressure distributed on the abrasives, and it depends on the interplay between the direct contact of the pad-to-wafer, and the contact of the abrasives with the wafer. The MRE can be increased by minimizing pad-wafer direct contact, as this is not likely to help material removal, significantly. The objective of this work is to investigate parameters that control MRE. This may be especially important for low-pressure CMP used in the polishing of (ultra-low-k) ULK dielectric materials. The optimization of CMP parameters to maximize the MRE is described by modeling the contact interactions between pad, abrasives and wafer. A relationship for optimal abrasive concentration is presented for the external load values that mark the transition from pure pad-wafer-abrasive contact to mixed contact (combination of pad-wafer-abrasive and pad-wafer contacts) and for given pad porosity and pad surface parameters.

Keywords

tribologyCMPpassivation
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 1157: Symposium E – Science and Technology of Chemical Mechanical Planarization (CMP) , 2009 , 1157-E12-02
Copyright
Copyright © Materials Research Society 2009

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References

1 Bozkaya, D., and Müftü, S., 2008. The effects of interfacial particles on the contact of an elastic sphere with a rigid flat surface. ASME Journal of Tribology, 130, 4, 041401.Google Scholar
2 Kim, A.T., Seok, J., Tichy, J.A., Cale, T.S., 2003. A multiscale elastohydrodynamic contact model for CMP. J Electrochem Soc, 150, 570–576.Google Scholar
3 Greenwood, J. A., Williamson, J. B. P., 1966. Contact of nominally flat surfaces. Proceedings of the Royal Society of London, Series A295, 300–319.Google Scholar
4 Guo, L., Subramanian, R.S., 2004. Mechanical removal in CMP of copper using alumina abrasives. J Electrochem Soc, 151, 104–108.Google Scholar
5 Bielmann, M., Mahajan, U., Singh, R. K., 2002. Effect of particle size during tungsten chemical mechanical polishing. Electrochem Solid State Letters, 2, 401–403.Google Scholar