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Si + SiH4 Reactions and Implications for Hot-Wire CVD of a-Si:H: Computational Studies

Published online by Cambridge University Press:  17 March 2011

Richard P. Muller
Affiliation:
Materials and Process Simulation Center
Jason K. Holt
Affiliation:
Department of Chemical Engineering
David G. Goodwin
Affiliation:
Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California, 91125
William A. Goddard III
Affiliation:
Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California, 91125
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Abstract

Gas phase chemistry is believed to play an important role in hot-wire CVD of amorphous silicon, serving to convert the highly-reactive atomic Si produced at the wire into a less-reactive species by reaction with ambient SiH4. In this paper, we use quantum chemistry computations (B3LYP/cc-pvTZ) to examine the energetics and rates of possible gas-phase reactions between Si and SiH4. The results indicate that formation of disilyne (Si2H2) is energetically favorable. Unlike other products of this reaction, Si2H2 does not require collisional stabilization, and thus this species is the most likely candidate for a benevolent precursor that participates in the growth of high-quality Si films.

Type
Research Article
Copyright
Copyright © Materials Research Society 2000

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References

REFERENCES

1. Doyle, J., Robertson, R., Lin, G. H. et al. , “Production of High-Quality Amorphous Silicon Films by Evaporative Silane Surface Decomposition”, Journal of Applied Physics 64 (6), 32153223 (1988).Google Scholar
2. Mahan, A. H., Nelson, B. P., Salamon, S. et al. , “Deposition of Device Quality, Low H Content a-Si:H by the Hot Wire Technique”, Journal of Non-Crystalline Solids 137/138, 657660 (1991).Google Scholar
3. Molenbroek, E. C., Mahan, A. H., Johnson, E. J. et al. , “Film Quality in Relation to Deposition Conditions of a-Si:H Films Deposited by the “Hot Wire” Method Using Highly Diluted Silane”, Journal of Applied Physics 79 (9), 72787292 (1996).Google Scholar
4. Molenbroek, E. C., Mahan, A. H., and Gallagher, A., “Mechanism Influencing “Hot-Wire” Deposition of Hydrogenated Amorphous Silicon”, Journal of Applied Physics 82 (4), 19091917 (1997).Google Scholar
5. Schropp, R.E. I., Feenstra, K. F., Molenbroek, E. C. et al. , “Device-Quality Polycrystalline and Amorphous Silicon Films by Hot-Wire Chemical Vapour Deposition”, Philosophical Magazine B 76 (3), 309321 (1997).Google Scholar
6. Goodwin, D. G., “Simulation of Hot-Wire Chemical Vapor Deposition of Hydrogenated Amorphous Silicon”, Electrochemical Society Proceedings 98 (23), 227232 (1998).Google Scholar
7. Hohenberg, P. and Kohn, Walter, “Inhomogeneous Electron Gas”, Physics Review 136, B864 (1964).Google Scholar
8. Kohn, Walter and Sham, L. J., “Self-Consistent Equations Including Exchange and Correlation Effects”, Physics Review 140, A1133 (1965).Google Scholar
9. Becke, Axel D., “Density Functional Thermochemistry III: The Role of Exact Exchange”, Journal of Chemical Physics 98, 5648, (1993).Google Scholar
10. Dunning, T.H., “Gaussian Basis Sets for use in Correlated Molecular Calculations. 1. The Atoms Boron Through Neon and Hydrogen”, Journal of Chemical Physics 90 (2), 10071023 (1989).Google Scholar
11. Ringnalda, Murco N., Langlois, Jean-Marc, Murphy, Robert B. et al. , Jaguar v3.0 (Schrodinger, Inc., Portland, Oregon, 1997, ).Google Scholar