Hostname: page-component-586b7cd67f-rdxmf Total loading time: 0 Render date: 2024-11-25T18:02:12.888Z Has data issue: false hasContentIssue false
  • English
  • Français

MechanicalModeling of the 2D Interfacial Slurry Pressure in CMP

Published online by Cambridge University Press:  01 February 2011

C. Fred Higgs III ,
Sum Huan Ng ,
Inho Yoon ,
Lei Shan ,
Lipkong Yap  and
Steven Danyluk
C. Fred Higgs III
Affiliation:
The George W. Woodruff School of Mechanical EngineeringGeorgia Institute of TechnologyAtlanta, GA. 30332-0405
Sum Huan Ng
Affiliation:
The George W. Woodruff School of Mechanical EngineeringGeorgia Institute of TechnologyAtlanta, GA. 30332-0405
Inho Yoon
Affiliation:
The George W. Woodruff School of Mechanical EngineeringGeorgia Institute of TechnologyAtlanta, GA. 30332-0405
Lei Shan
Affiliation:
The George W. Woodruff School of Mechanical EngineeringGeorgia Institute of TechnologyAtlanta, GA. 30332-0405
Lipkong Yap
Affiliation:
The George W. Woodruff School of Mechanical EngineeringGeorgia Institute of TechnologyAtlanta, GA. 30332-0405
Steven Danyluk
Affiliation:
The George W. Woodruff School of Mechanical EngineeringGeorgia Institute of TechnologyAtlanta, GA. 30332-0405
Get access

Abstract

Chemical mechanical polishing (CMP) is a manufacturing process used to remove or planarize metallic, dielectric, or barrier layers on silicon wafers. During polishing, a wafer is pressed against an elastic pad that is flooded with slurry. Prior work has shown that an asymmetrical, subambient pressure develops at the interface between the silicon and the pad during polishing. Since the slurry pressure is on the order of the wafer-on-pad contact stress, the total contact pressure is asymmetrical. This promotes a non-uniform polishing rate, since Preston's equation states that the material removal rate is proportional to the total contact pressure. In order to determine the total contact pressure, experiments were conducted to measure the two-dimensional fluid pressure. A superposition method was then employed to calculate the slurry film thickness by performing an equilibrium analysis of the forces and moments created by the fluid and solid interactions. The film thickness obtained by this method is used to model the slurry pressure using the polar Reynolds' equation. Modeling results qualitatively agree with experiments.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 767: Symposium F – Chemical-Mechanical Planarization , 2003 , F7
Copyright
Copyright © Materials Research Society 2003

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. Levert, J., Danyluk, S., and Tichy, J., Mechanism for subambient interfacial pressures while polishing with liquids. Journal of Tribology, 2000. 122: p. 450.Google Scholar
2. Levert, J., Baker, A., Mess, F., Danyluk, S., Salant, R., and Cook, L., Slurry Film Measurements for Chemical Mechanical Polishing. Proc. of the Am. Soc. of Precision Engineering, 1996. 14: p. 80–85.Google Scholar
3. Shan, L., Levert, J., Meade, L., Tichy, J., Danyluk, S., Interfacial Fluid Mechanics and Pressure Prediction in Chemical Mechanical Polishing. Journal of Tribology, 2000. 122: p. 539–543.Google Scholar
4. Greenwood, J.A. and Williamson, J.B., Contact of Nominally Flat Rough Surfaces. Proc. Royal Society of London, 1966. A295: p. 300–319.Google Scholar
5. Shan, L., Mechanical interactions at the interface of chemical mechanical polishing. 2000, Ph.D. Thesis, Georgia Institute of Technology: Atlanta.Google Scholar
6. Kim, A., Seok, J., Sukam, C., Tichy, J., Cale, T. Multiscale material removal modeling of chemical mechanical polishing. in Adv. Metallization Conf. 2001.Google Scholar
7. Streator, J. A Model of Mixed Lubrication with Capillary Effects. in Proceedings of the 28th Leeds-Lyon Symposium on Tribology--Boundary and Mixed Lubrication: Science and Applications. 2001. Leeds, England.Google Scholar
8. Johnson, K.L., Contact Mechanics. 1985, Cambridge, UK: Cambridge University Press.Google Scholar
9. Hamrock, B.J., Fundamentals of Fluid Film Lubrication. 1994: McGraw-Hill.Google Scholar
10. Patir, N. and Cheng, H., An Average Flow Model for Determining Effects of Three-Dimensional Roughness on Partial Hydrodynamic Lubrication. ASME J. Lubrication Technology. 1978. Vol. 100(1): p. 12–17.Google Scholar
11. Higgs, C. III, Ng, S.H., Yoon, I., Yap, L., and Danyluk, S.. Predicting the Hydrodynamic Slurry Pressure in CMP: Modeling and Experiments. In Preparation for the Journal of Tribology, 2003.Google Scholar