Hostname: page-component-76fb5796d-22dnz Total loading time: 0 Render date: 2024-04-25T11:44:42.223Z Has data issue: false hasContentIssue false
  • English
  • Français

A Model for Silicon Dendrite Growth During Laser/Plasma Deposition from a Silane Discharge

Published online by Cambridge University Press:  28 February 2011

Harold M. Anderson  and
Philip J. Hargis Jr.
Harold M. Anderson
Affiliation:
Department of Chemical & Nuclear Engineering, University of New Mexico, Albuquerque, NM 87131
Philip J. Hargis Jr.
Affiliation:
Sandia National Laboratories, Albuquerque, NM 87185
Get access

Abstract

A model for dendrite growths in polycrystalline Si films formed during laser/plasma deposition with a silane discharge and a pulsed KrF laser has been developed. The model assumes a thin (less than 10 nm) amorphous silicon (a-Si) film is deposited on a substrate prior to phase transformation due to laser heating. The observed dendritic structure of the overall polycrystalline Si films is attributed to Si crystals shooting from an excessively supercooled Si liquid bath. Supercooled liquid forms since the melting point for a-Si can be reached at relatively low KrF laser fluences. Latent heat evolved at the solid-liquid interface induces an interface temperature higher than that of the melt and the requisite negative temperature gradient for absolute bath supercooling. Since the formation of an undercooled liquid by fast melting a-Si is also an important first step in explosive crystal regrowth studies, these results may have important implications for crystal growth and transient annealing. A conical approximation model is used in this study to characterize the stability of the dendrite tip in terms of local temperature gradients, i.e., the degree of undercooling at the tip of the parabolic dendrite. The degree of undercooling and hence the tip radius appears to be significantly affected by small changes in the laser fluence. Stability criteria lead to a relationship between regrowth velocity, V, and the tip radius, R, of the form VR2= constant. The size and stability of the dendrite tip is determined from a balance between the destabilizing force due to thermal diffusion and the stabilizing capillary force. Based on the observed tip radii formed at laser fluences from 0.13 to 0.25 J/cm2, the model predicts regrowth velocities in a range between 2.0 and 20 m/s – values consistent with transient annealing studies of a-Si

Type
Articles
Information
MRS Online Proceedings Library (OPL) , Volume 75: Symposium B – Photon, Beam, and Plasma Stimulated Chemical Processes at Surfaces , 1986 , 755
Copyright
Copyright © Materials Research Society 1987

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. Gee, J.M. and Hargis, P.J. Jr., in SPIE Vol.459, Laser Assisted Deposition, Etching, and Doping (SPIE, Bellingham, WA, 1984) p. 132.CrossRefGoogle Scholar
2. Hargis, P.J. and Gee, J.M., Solid State Tech., 27(11), 127 (1984).Google Scholar
3. Huang, S.-C. and Glicksman, M.E., Acta Met., 29, 701 (1981).CrossRefGoogle Scholar
4. Trevedi, R., J. Crystal Growth, 73, 289 (1985).CrossRefGoogle Scholar
5. Poate, J.M., in Mat. Res. Soc. Symp. Vol.13, edited by Narayan, J., Brown, W.L., and Lemmons, R.A. (Elsevier Science Publishers, NY, 1983), p. 263.Google Scholar
6. Cullis, A.G., in Mat. Res. Soc. Symp. Vol 35, edited by Biegelsen, D.K.,Rozgonyi, G., Shank, C. (Materials Research Soc., Pittsburgh, 1985), p. 18.Google Scholar
7. Wood, R.F. and Geist, G.A., Phys. Rev. B, 34(4), 2606 (1986).CrossRefGoogle Scholar
8. Narayan, J., White, C.W., Aziz, M.J., Stritzker, B., and Walthius, A., J. Appl. Phys., 57(2), 564 (1985).CrossRefGoogle Scholar
9. Lee, El-Hang, in Mat. Res. Soc. Symp. Vol.35, edited by Biegelsen, D.K.,Rozgonyi, G., Shank, C. (Materials Research Soc., Pittsburgh, 1985), p. 564.Google Scholar
10. Oldfield, W., Mater. Sci. Engng, 11, 211 (1973).CrossRefGoogle Scholar
11. Skapski, A.S., Acta Met. 4, 576 (1956).CrossRefGoogle Scholar