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On The Melting of Amorphous Ge and Si

Published online by Cambridge University Press:  15 February 2011

David Turnbull
David Turnbull*
Affiliation:
Division of Applied Sciences, Harvard University, Cambridge, MA 02138, USA
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Abstract

The amorphous semiconducting phase (a-sc) of Si or Ge is so resistant to crystallization that rapid heating may bring it into a temperature regime in which it melts. Such melting might occur in one or the other of two ways, either homogeneously, by the reverse of the glass transition, to a viscous semi-conducting melt (ℓ-sc) or by transition, probably by nucleation and growth, to the molten metallic state (ℓm). Using the self-diffusion constant of the crystalline elements in conjunction with the Stokes-Einstein equation, upper limiting values of the glass transition (a-sc→ℓ-sc) temperatures of Si and Ge were calculated. These were of the order 0.6 to 0.65 Tcℓ for slow and 1.1 Tcℓ for ultra rapid heating, where Tcℓ is the equilibrium melting temperature of the crystal. Arguments are given that superheating to a temperature 1.15 to 1.25 Taℓ (a-sc↔ℓm in equilibrium at temperature T = Taℓ< Tcℓ) may be required for copious internal nucleation of im in a-sc. At lesser superheating the transition must be initiated at internal flaws (e.g. voids) or at the external surface of the a-sc film. Therefore the superheating at perceptible onset of the transition during rapid heating can vary widely from specimen to specimen, depending on the flaw concentration and how the external surface of a-sc was treated.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 7 , 1981 , 103
Copyright
Copyright © Materials Research Society 1982

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References

REFERENCES

1.Bagley, B.G. and Chen, H.S., “Laser-Solids Interactions and Laser Processing” (eds. Ferris, S.D., Leamy, H.J. and Poate, J.M.) Am. Inst. Phys. Conf. Proc. 5097 (1979).Google Scholar
2.Spaepen, F. and Turnbull, D., ibid. 50, 73 (1979).Google Scholar
3.Fan, John C.C. and Anderson, Carl H. Jr., J. Appl. Phys. 52, 4003 (1981).Google Scholar
4.Donovan, E.P. and Poate, J.M., Reported at the “NATO Institute on Surface Modification and Alloying”, Trevi, Italy, August 1981, to be a NATO publication.Google Scholar
5.Liu, J.M., Yen, R., Bloembergen, N. and Hodgson, R.T., Appl. Phys. Letters 34, 864 (1979).Google Scholar
6.Liu, J.M., Yen, R., Donovan, E.P., Bloembergen, N. and Hodgson, R.T., Appl. Phys. Letters 38, 617 (1981).Google Scholar
7.Spaepen, F. and Turnbull, D. in “Laser and Electron Beam Processing of Semiconductor Structures”, Academic Press, N.Y., in press.Google Scholar
8.Baeri, P., Foti, G., Poate, J.M. and Cullis, A.G., Phys. Rev. Letters 45, 2036 (1980).Google Scholar
9.Knapp, J.A. and Picarux, S.T., Appl. Phys. Letters 38, 873 (1981).Google Scholar
10.Kokorowski, S.A., Olson, G.L., Hess, L.D., submitted to J. Appl. Phys.Google Scholar
11.Letaw, H. Jr., Portnoy, W.M. and Slifkin, L., Phys. Rev. 102, 636 (1956).Google Scholar
12.Fairfield, J.M. and Masters, B.J., J. Appl. Phys. 38, 3148 (1967).Google Scholar
13.Czepregi, L., Kennedy, E.F., Mayer, J.W. and Sigmon, T.W., J. Appl. Phys. 49, 3906 (1978).Google Scholar