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Afterglow Chemical Processing for Oxide Growth on Silicon Carbide

Published online by Cambridge University Press:  01 February 2011

Andrew M Hoff
Affiliation:
[email protected], University of South Florida, Electrical Engineering, Tampa, Florida, United States
Eugene Short
Affiliation:
[email protected], University of South Florida, Electrical Engineering, Tampa, Florida, United States
Helen B Thomas
Affiliation:
[email protected], University of South Florida, Electrical Engineering, Tampa, Florida, United States
Elena I Oborina
Affiliation:
[email protected], University of South Florida, Electrical Engineering, Tampa, Florida, United States
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Abstract

The unique capabilities and characteristics provided by afterglow or remote plasma chemical oxide growth processing of silicon carbide are reviewed. Such processing provides for thermal growth of oxide films at temperatures far below those employed by conventional atmospheric processing methods. Overshadowing this growth capability is the ability to create chemistries, sequential procedures, and specific process environments to address material and defect issues in a manner not possible under conventional atmospheric conditions. The details and outcomes of multi-step afterglow oxidation processing of SiC will be discussed. An example sequence might include; 1) surface conditioning, 2) film growth at 850C and 1 Torr total pressure, and 3) reduced pressure unexcited media post-growth treatments. Surface conditioning impacts the thickness uniformity of the final oxide film and the oxidation rate. The film growth interval produces a nominal 500Å of oxide film in 90 minutes at 850C, a temperature that would not produce any significant oxide film at atmospheric pressure. And the post-growth processing improves the performance of the dielectric film. Using in-line corona-Kelvin metrology the electrical characteristics stemming from these processes have been determined. Electrical effective oxide thickness results were used to assess thickness uniformity and to estimate process rate constants for comparison to other process methods. Fowler-Nordheim, F-N, characteristics determined with the same metrology demonstrate that afterglow, AG, oxides require higher field levels to produce the same F-N current as thermal oxides and that AG films are less susceptible to stress fluence. Process extensions from these and other results are discussed and related to chemical, physical, and electrical film outcomes and potential pathways to improve control over dielectric SiC structures.

Type
Research Article
Copyright
Copyright © Materials Research Society 2010

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References

[1] Deal, B. E. and Grove, A. S., “General Relationship for Thermal Oxidation of Silicon,” Journal of Applied Physics, vol. 36, pp. 3770-&, 1965.Google Scholar
[2] Song, Y., Dhar, S., Feldman, L. C., Chung, G., and Williams, J. R., “Modified Deal Grove model for the thermal oxidation of silicon carbide,” Journal of Applied Physics, vol. 95, pp. 49534957, May 2004.Google Scholar
[3] Hoff, A. M., Tibrewala, A., and Saddow, S. E., “Afterglow Thermal Oxidation of Silicon Carbide,” Silicon Carbide 2002--Materials, Processing and Devices, MRS Proceedings 742, 2002.Google Scholar
[4] Hoff, A. M., “Growth and Metrology of Silicon Oxides on Silicon Carbide,” Materials Research Society, MRS Proceedings 815, pp. 189198, 2004.Google Scholar
[5] Cook, J. M. and Benson, B. W., “Application of Electron-Paramagnetic-Res Spectroscopy to Oxidative Removal of Organic Materials,” Journal of the Electrochemical Society, vol. 130, pp. 24592464, 1983.Google Scholar
[6] Oborina, E. I. and Hoff, A. M., “Non-contact interface trap determination of SiO2-4H-SiC structuresJournal of Applied Physics, vol. 106, 15 Dec 2009.Google Scholar
[7] Savtchouk, A., Oborina, E., Hoff, A. M., and Lagowski, J., “Non-contact doping profiling in epitaxial SiC,” in Silicon Carbide and Related Materials 2003, Pts 1 and 2. vol. 457–460, 2004, pp. 755758.Google Scholar
[8] Kern, W. and Puotinen, D. A., “Cleaning Solutions Based on Hydrogen Peroxide for Use in Silicon Semiconductor Technology,” Rca Review, vol. 31, pp. 187-&, 1970.Google Scholar
[9] Chang, K., Witt, T., Hoff, A. M., Woodin, R., Ridley, R., Dolny, G., Shanmugasundaram, K., Oborina, E., and Ruzyllo, J., “Surface roughness in silicon carbide technology,” in Cleaning Technology in Semiconductor Device Manufacturing IX. vol. T200500103, Ruzyllo, J., Hattori, T., and Novak, R., Eds. Los Angeles, California: The Electrochemical Society, 2005, p. 228.Google Scholar
[10] Peeters, J. and Li, L., “Oxidation of Silicon in Plasma Afterglows - New Model of Oxide-Growth Including Recombination of Diffusing O-Atoms,” Journal of Applied Physics, vol. 73, pp. 24772485, Mar 1993.Google Scholar
[11] Spencer, J. E., Borel, R. A., and Hoff, A. M., “High-Rate Photoresist Stripping in an Oxygen Afterglow,” Journal of the Electrochemical Society, vol. 133, pp. 19221925, Sep 1986.Google Scholar
[12] Spencer, J. E., Jackson, R. L., and Hoff, A., “New Directions in Dry Processing Using the Flowing Afterglow of a Microwave-Discharge,” Journal of the Electrochemical Society, vol. 133, pp. C310–C310, Aug 1986.Google Scholar
[13] Spencer, J. E., Jackson, R. L., and Hoff, A. M., “New Directions in Plasma Processing,” 170th ECS Meeting, 6th Symposium on Plasma Processing, PV198706, p. 186, 1986.Google Scholar
[14]SDI, “FAaST Tools,” Semilab SDI LLC, http://www.sditampa.com, 2010.Google Scholar
[15] Oborina, E. I., Benjamin, H. N., and Hoff, A. M., “Fowler--Nordheim analysis of oxides on 4H-SiC substrates using noncontact metrology,” Journal of Applied Physics, vol. 106, p. 083703, 2009.Google Scholar
[16] Hoff, A. M. and Oborina, E., “Fast Non-Contact Dielectric Characterization for SiC MOS Processing,” Devaty, R. P., Larkin, D. J., and Saddow, S. E., Eds., 2006, pp. 10351038.Google Scholar
[17] Seyller, T., “Electronic properties of SiC surfaces and interfaces: some fundamental and technological aspects,” Applied Physics a-Materials Science & Processing, vol. 85, pp. 371385, Dec 2006.Google Scholar
[18] Losurdo, M., Giangregorio, M. M., Capezzuto, P., Bruno, G., Brown, A. S., Kim, T. H., and Yi, C. H., “Modification of 4H-SiC and 6H-SiC(0001)(Si) surfaces through the interaction with atomic hydrogen and nitrogen,” Journal of Electronic Materials, vol. 34, pp. 457465, Apr 2005.Google Scholar
[19] Hoff, A. M., “XPS Measurements of 4H-SiC Comparing Excited Forming Gas Surface Treatment with Standard Clean Treatment,” 2009.Google Scholar
[20] Boisse-Laporte, C., Chave-Normand, C., and Marec, J., “A microwave plasma source of neutral nitrogen atoms,” Plasma Sources Sci. Technol., vol. 6, pp. 7077, 1997.Google Scholar