Hostname: page-component-586b7cd67f-rdxmf Total loading time: 0 Render date: 2024-11-25T18:01:34.487Z Has data issue: false hasContentIssue false

Reduced-Pressure UV Photo-Oxidation of Organic Contaminants on Si Surfaces

Published online by Cambridge University Press:  15 February 2011

Satish Bedge
Affiliation:
Department of Chemical Engineering and Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695-7905
H. Henry Lamb
Affiliation:
Department of Chemical Engineering and Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695-7905
Get access

Abstract

A reduced-pressure ultraviolet (UV) photo-oxidation process is described for the removal of organic contamination from Si surfaces with concomitant growth of an ultra-thin oxide passivation layer. As in situ photo-generation of ozone (O3) from dioxygen (O2) is impractical at millitorr pressures, a 2% O3/O2 mixture from an ozone generator is fed to the surface conditioning chamber. UV/O3 surface conditioning employing simultaneous 254/185 nm UV irradiation results in essentially complete removal of carbon contamination in 180 s at 100 mTorr and 100–200°C. Kinetics studies employing cyclohexane-contaminated Si(100) surfaces suggest that carbon removal occurs via two consecutive first-order processes: initial fast photo-oxidation of adsorbed cyclohexane to readily desorbed products and slower photo-oxidation of adsorbed carbonyl intermediates to CO2 and H2O. The activation energies for both processes are 2–3 kcal/mol, consistent with the involvement of photo-generated atomic oxygen species. Self-limiting growth of an ultra-thin oxide passivation layer occurs concomitantly with carbon removal. At saturation, the oxide layer is only 3–4 Å thick, and the growth kinetics are described by a first-order Langmuirian adsorption model.

Type
Research Article
Copyright
Copyright © Materials Research Society 1995

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. Kasi, S. R. and Liehr, M., J. Vac. Sci. Technol. A, 10 (4), 795 (1992).Google Scholar
2 Offenberg, M., Liehr, M., and Rubloff, G. W., J. Vac. Sci. Technol. A, 9 (3), 1058 (1991).Google Scholar
3 Kern, W. and Puotinen, D. A., RCA Rev. 31, 187 (1970).Google Scholar
4 Schneider, T. P., Bernhard, B. L., Chen, Y. L., and Nemanich, R. J., Mat. Res. Soc. Symp. Proc. 259, 213 (1992).Google Scholar
5 Liu, H. X., Schneider, T. P., Montgomery, J., Chen, Y. L., Buczkowski, A., Shimura, F., Nemanich, R. J., Maher, D. M., Korzec, D. and Engemann, J., Mat. Res. Soc. Symp. Proc. 315, 231 (1993).Google Scholar
6 Ma, Y., Yasuda, T., Habermehl, S., He, S. S., Stephens, D. J. and Lucovsky, G., Mat. Res. Soc. Symp. Proc. 259, 69 (1992).Google Scholar
7 Vig, J. R., in Treatise on Clean Surface Technology; edited by Mittal, K. L. (Plenum Press, New York, 1987) pp 126.Google Scholar
8 Ruzyllo, J., Duranko, G., and Hoff, A., J. Electrochem. Soc. 134, 2052 (1987).Google Scholar
9 Tabe, M., Appl. Phys. Lett. 45, 1073 (1984).Google Scholar
10 Bedge, S., Ruggles, G. A., and Lamb, H. H.in Proceedings of the Second International Symposium on Cleaning Technology in Semiconductor Device Manufacturing, edited by Ruzyllo, J. and Novak, R. (The Electrochemical Society, Pennington, NJ, 1991) pp. 112121.Google Scholar
11 Bedge, S. and Lamb, H. H., to be published.Google Scholar
12 Davis, L. E., MacDonald, N. C., Palmberg, P. W., Riach, G. E., and Weber, R. E., Handbook of Auger Electron Spectroscopy; (Physical Electronics, Eden Prairie, MN, 1976).Google Scholar
13 Finlayson-Pitts, B. and Pitts, J., Atmospheric Chemistry: Fundamentals and Experimental Techniques; (Wiley Press, New York, 1986).Google Scholar
14 Bedge, S., McFadyen, J., and Lamb, H. H., Mat. Res. Soc. Symp. Proc. 259, 207 (1992).Google Scholar
15 Warneck, P., Chemistry of the Natural Atmosphere; (Academic Press, San Diego, 1987).Google Scholar
16 Wayne, R. P., in Singlet Oxygen: Physical-Chemical Aspects; edited by Frimer, A. A. (CRC Press, Boca Raton, FL, 1985).Google Scholar
17 Kasi, S. R. and Liehr, M., Appl. Phys. Lett. 57, 2095 (1990).Google Scholar
18 Himsel, F. J., McFeely, F. R., Taleb-Ibrahimi, A., Yarmoff, J. A., Phys. Rev. 38, 6084 (1988).Google Scholar
19 Engstrom, J. R., Bonser, D. J., and Engel, T., Surf. Sci. 268, 238 (1992).Google Scholar