Page 60 - Semiconductor Manufacturing Handbook

Geng(SMH)_CH05.qxd 04/04/2005 19:37 Page 5.9

FUNDAMENTALS OF SILICIDE FORMATION ON Si

FUNDAMENTALS OF SILICIDE FORMATION ON Si 5.9

straight at all. It is possible that we may be able to grow straight nano-Si wires via the nano-Pd Si
2
particles.
It is known that NiSi and CoSi have the CaF cubic crystal structure and they have a very small
2 2 2
lattice misfit to Si. Superlattice of CoSi /Si/ CoSi /Si with nanoscale period has been grown. On the
2 2
38
other hand, nanoscale NiSi particles on (111) Si have been observed. Nevertheless, superlattice or
2
epitaxial growth of CoSi and NiSi thin films on (100) Si is much more difficult; furthermore, the
2 2
growth in nanoscale has not been studied.
5.4 CONCLUSIONS
The application of silicides is essential for modern microelectronics. The main requirements for sili-
cides are good conductivity, reliability, and manufacturability. In order to form good silicides with
low resistivity and low contact resistance, a detailed knowledge of their thermodynamic, electrical,
and mechanical properties, and their stability at high temperature is needed. Based on the criteria
mentioned in this chapter, the RTA silicide process has been introduced in detail with standard
CMOS integrated-circuit fabrication. Due to a more complicated demand for submicron CMOS
technology, novel silicide development has received much attention for next generation VLSI.

REFERENCES

1. Maex, K., and M. V. Rossum, Properties of Metal Silicides, United Kingdom: INSPEC, the Institution of
Electrical Engineers, 1995.
2. Yamaguchi, Y., et al., “Self-aligned silicide technology for ultra-thin SIMOX MOSFETs,” IEEE Trans.
Electron Dev., Vol. 39, p. 1179, 1992.
3. Murarka, S. P., et al., “Resistivities of thin film transition metal silicides,” J. Electrochem. Soc., Vol. 129,
p. 293, 1982.
4. Nava, F., et al., “Electrical and optical properties of silicide single crystals and thin films,” Mater. Sci. Rep.,
Vol. 9, pp. 141–200, 1993.
5. Sze, S. M., Physics of Semiconductor Devices, 2d ed., New York: Wiley, 1981.
6. Liehr, M., et al., “Correlation of Schottky-barrier height and microstructure in the epitaxial Ni silicide on
Si(111),” Phys. Rev. Lett., Vol. 54, p. 2139, 1985.
7. Ho, P. S., “Chemical bonding and Schottky barrier formation at transition metal-silicon interfaces,” J. Vac.
Sci. Technol. A, Vol. 1, p. 745, 1983.
8. Ottaviani, G., K. N. Tu, and J. W. Mayer, “Barrier heights and silicide formation for Ni, Pd, and Pt on sili-
con,” Phys. Rev. B, Vol. 34, p. 3354, 1981.
9. Thompson, R. D., and K. N. Tu, “Comparison of the three classes (rare earth, refractory and near-noble) of
silicide contacts,” Thin Solid Film, Vol. 93, p. 265, 1982.
10. Taur, Y., and T. H. Ning, Fundamentals of Modern VLSI Devices, p. 243, United Kingdom: Cambridge
University Press, 1998.
11. Murarka, S. P., Silicides for VLSI Applications, Orlando: Academic Press, 1983.
12. NBS Monograph 25 (USA) No. 21, p. 126, 1984.
13. Wong-Ng, W., et al., NBS Grant-in-Aid Report, 1987.
14. Ishida, K., T. Nishizawa, and M. E. Schlesinger, “The Co-Si (Cobalt-Silicon) System,” J. Phase Equilibria,
Vol. 12, p. 578, 1991.
15. d’Heurle, F., et al., “Formation of thin films of NiSi: Metastable structure, diffusion mechanisms in inter-
metallic compounds,” J. Appl. Phys.,Vol. 55, p. 4208, 1984.
16. Nash, P., and A. Nash, Bull. Alloy Phase Diagrams, Vol. 8, p. 6, 1987.
17. Samsonov, G. V., and I. M. Vinitskii, Handbook of Refractory Compounds, New York: IFI/Plenum, 1980.

Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com)
Copyright © 2004 The McGraw-Hill Companies. All rights reserved.
Any use is subject to the Terms of Use as given at the website.