Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-22T19:45:32.186Z Has data issue: false hasContentIssue false

Polyurethane Pad Degradation and Wear Due to Tungsten and Oxide CMP

Published online by Cambridge University Press:  18 March 2011

Amy L. Moy
Affiliation:
University of New Mexico, Department of Chemical and Nuclear Engineering, 209 Farris Engineering Center, Albuquerque, NM 87131, U.S.A.
Joseph L. Cecchi
Affiliation:
University of New Mexico, Department of Chemical and Nuclear Engineering, 209 Farris Engineering Center, Albuquerque, NM 87131, U.S.A.
Dale L. Hetherington
Affiliation:
Sandia National Laboratories, P.O. Box 5800, Albuquerque, NM 87123, U.S.A.
David J. Stein
Affiliation:
Sandia National Laboratories, P.O. Box 5800, Albuquerque, NM 87123, U.S.A.
Get access

Abstract

Polyurethane polishing pads are commonly used for chemical-mechanical polishing (CMP) of semiconductor wafers. Structural, chemical, and mechanical property changes of the polishing pads due to CMP are examined. Tungsten and oxide film layers are polished from the wafer surface using the polishing pad and abrasive slurry system. The polishing pad surface is flattened with polishing, and hence, reducing the effective area for slurry transport. The abrasive is used for abrading off the film from the surface. W, Al, I, and K accumulate in the polishing pad after tungsten CMP and Si accumulates after oxide CMP. Material accumulates in the pad pores and grooves. Electron Microprobe X-ray Analysis and Wavelength Dispersive Spectrometry (WDS) were used to examine the changes across the thickness of the pad. Fourier Transform Infrared Spectroscopy (FTIR) was used to determine the changes to the polyurethane isocyanate group. The reduction in the isocyanate group and increase in the hydroxyl group after tungsten CMP indicates that a hydrolysis reaction of the isocyanate to form carboxylic acid occurs.

Type
Research Article
Copyright
Copyright © Materials Research Society 2001

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

REFERENCES

[1] Cumbo, M. J., Fairhurst, D., Jacobs, S. D., and Puchebner, B. E., Applied Optics, 34 (19), 3743 (July 1, 1995).Google Scholar
[2] Subramanian, R., Zhang, L., and Babu, S., J. Electrochem. Soc., 146(11), 4263 (1999); D. J. Stein, D. L. Hetherington, T. Guilinger, and J. L. Cecchi, 145(9), 3195 (September 1998).10.1149/1.1392626Google Scholar
[3] Cook, L. M., Wang, J., James, D., and Sethuraman, A., Semiconductor International (1995).Google Scholar
[4] Moy, A. L., Cecchi, J. L., Hetherington, D. L., and Stein, D. J., presented at the 2001 Spring CMP-MIC Conference, Santa Clara, CA, 2001 “Polyurethane Pad Degradation and Wear Due to Tungsten and Oxide Chemical Mechanical Polishing (CMP).”Google Scholar
[5] Young, R. J. and Lovell, P. A., in Introduction to Polymers, 2nd Edition (Chapman & Hall, London, 1991).10.1007/978-1-4899-3176-4Google Scholar
[6] Montgomery, D. C., in Design and Analysis of Experiments, 5th Edition (Wiley & Sons, New York, 2001).Google Scholar