Hostname: page-component-848d4c4894-ndmmz Total loading time: 0 Render date: 2024-05-01T05:14:24.049Z Has data issue: false hasContentIssue false
  • English
  • Français

The Mechanism of Excimer Laser-Induced Amorphization of Ultra-Thin Si Films

Published online by Cambridge University Press:  15 February 2011

T. Eiumchotchawalit  and
James S. Im
T. Eiumchotchawalit
Affiliation:
Columbia University, Department of Chemical Engineering, Materials Science and Mining Engineering, New York, NY
James S. Im
Affiliation:
Columbia University, Department of Chemical Engineering, Materials Science and Mining Engineering, New York, NY
Get access

Abstract

To better understand the involved phase transformation Mechanism, we are studying the excimer laser-induced amorphization (ELA) of ultra-thin Si films on oxidized Si substrates. In this paper, we show that the onset of amorphization of hydrogen-free Si films on SiO2 substrates upon increases in the energy density is associated with the onset of complete melting of the film. Once complete melting occurs, further increases in the incident energy density and/or increases in the substrate temperature can lead to incomplete amorphization of the film. Planar view TEM analysis of nearly-amorphized Si films reveals a heterogeneous microstructure, which consists of a mixture of densely dispersed amorphous-like annular regions (∼20 to 40 μm−2), embedded within and typically separated by a region containing finegrained small crystals. Such a cellular microstructure strongly suggests that amorphization occurred not via a homogeneous but via a heterogeneous transformation. In particular, the microstructure paints a scenario in which amorphization proceeded via nucleation of solids, which is then followed by interfacial amorphization. The experimental results unambiguously reveal (1) that the previously proposed criteria of the melt duration and the vertical temperature gradient are irrelevant in determining amorphization of supercooled liquid Si films and (2) that the quenching rate, not surprisingly, is the important parameter.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 321: Symposium E – Crystallization and Related Phenomena in Amorphous Materials—Ceramics, Metals, Polymers, and Semiconductors , 1993 , 725
Copyright
Copyright © Materials Research Society 1994

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

REFERENCES

1. Sameshima, T. and Usui, S., Appl. Phys. Lett. 59 2724 (1991).Google Scholar
2. Sameshima, T. and Usui, S., J. Appl. Phys. 74, 6592 (1993).Google Scholar
3. Dutartre, D., J. Appl. Phys. 59, 1977 (1986).Google Scholar
4. Süffler, S. R., Thompson, M. O., Peercy, P. S., Phys. Rev. Lett. 60, 2519 (1988).Google Scholar
5. Thompson, M. O., Mayer, J. W., Cullis, A. G., Webber, H. C., Chew, N. G., Poate, J. M. and Jacobson, D. C., Phys. Rev. Lett. 50, 896, (1983).Google Scholar
6. Kim, Yeon-Wook, Lin, Hong-Ming and Kelly, T. F., Actametall 37, 247 (1989).Google Scholar
7. Evans, P. V., Devaud, G., Kelly, T. F., and Kim, Yeon-Wook, Actametall 38, 719 (1990).Google Scholar
8. Im, James S., Kim, H. J., and Thompson, M. O., Appl. Phys. Lett. 63, 1969 (1993).Google Scholar
Kim, H. J., Im, James S., and Thompson, M. O., Mat. Res. Soc. Symp. Proc 283, 703 (1993).Google Scholar
9. Gettis, A. and Boots, B., Models of Spatial Processes (Cambridge, UK: Cambridge University Press, 1979).Google Scholar
10. Süffler, S. R., Thompson, M. O., Peercy, P. S., Phys. Rev. B 43, 9851 (1991).Google Scholar
11. Stolk, P. A., Polman, A., and Sinke, W. C., Phys. Rev. B 47, 5 (1993).Google Scholar
12. Turnbull, D., Mat. Res. Soc. Symp. Proc. 51, 71 (1985).Google Scholar
13. Poate, J. M., Mat. Res. Soc. Symp. Proc. 13, 263 (1983).Google Scholar
14. Broughton, J. Q. and Li, X. P., Phys. Rev. B 35, 9120 (1987).Google Scholar