Hostname: page-component-77c89778f8-n9wrp Total loading time: 0 Render date: 2024-07-23T08:54:01.145Z Has data issue: false hasContentIssue false

Metrology Study of Sub 20Å Oxynitride by Corona-Oxide-Silicon (COS) and Conventional C-V Approaches

Published online by Cambridge University Press:  01 February 2011

Pui Yee Hung
Affiliation:
International Sematech, Austin, TX 78741, U.S.A.
George A. Brown
Affiliation:
International Sematech, Austin, TX 78741, U.S.A.
Michelle Zhang
Affiliation:
KLA-Tencor Corporation, San Jose, CA 95134, U.S.A.
Joe Bennett
Affiliation:
International Sematech, Austin, TX 78741, U.S.A.
Husam N. AL-Shareef
Affiliation:
International Sematech, Austin, TX 78741, U.S.A.
Chadwin Young
Affiliation:
International Sematech, Austin, TX 78741, U.S.A.
Chris Oroshiba
Affiliation:
KLA-Tencor Corporation, San Jose, CA 95134, U.S.A.
Alain Diebold
Affiliation:
International Sematech, Austin, TX 78741, U.S.A.
Get access

Abstract

This work aims to develop an in-line corona-oxide-silicon (COS) monitoring strategy for the sub 20 Å oxynitride gate dielectrics. The oxynitride gate dielectrics were composed of In-Situ Steam Generated oxide (ISSG) oxide at thickness of 16Å and 20Å which were exposed to Remote Plasma Nitridation (RPN) for various time durations. The nitrogen density in the oxynitride established by SIMS and nuclear reaction analysis (NRA), was correlated with the non-contact electrical measurements taken by Quantox™. The non-contact electrical parameters included interface trap density (Dit), flatband voltage (Vfb), total charge (Qtot), equivalent oxide thickness (EOT) and leakage current. The pre-anneal Dit measurements exhibited a strong correlation with the nitrogen density and was the most sensitive process monitoring parameter. The Vfb and Qtot, on the other hand, showed little correlation. The ISSG/RPN oxynitride process required further optimization because there was no significant reduction in EOT for the annealed samples. Furthermore, the leakage current in the pre-annealed samples increased with the RPN exposure possibly indicating plasma damage. Conventional MOS C-V measurements were also conducted. Similar to the Qunatox™ results, there were no reductions in EOT or current density. A comparison between the C-V and the Quantox™ data indicated no simple linear relationship between these two techniques. Due to the limited samples used for the Quantox™/ C-V comparison, a more extensive work is required to confirm the present observation.

Type
Research Article
Copyright
Copyright © Materials Research Society 2002

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. Cartier, E, Buchanan, D. A., and Dunn, G. J., Appl.Phys. Lett. 64, 901(1994)Google Scholar
2. Gusev, E. P., Lu, H. C., Garfunkel, E, Gustafsson, T., and Green, M., IBM J Research and Development, 43, 265 (1999)Google Scholar
3. AL-Shareef, H.N., Karamcheti, A, Luo, T. Y., Bersuker, G., Brown, G. A., and Murto, R. W., Appl. Phys. Lett. 78, 1 (2001)Google Scholar
4. Hauser, J. R. and Ahmed, K, in Characterization and Metrology for ULSI Technology:1998 International Conference, Raleigh, NC, 1998, pp. 235239.Google Scholar