Abstract
High quality epitaxial Sil−xGex/Si (x = 0.09 to 0.27) samples were studied with polarized Raman scattering technique. The LO (longitudinal optical) -TO (transversal optical) phonon mode splitting due to the tetragonal strain imposed by the lattice mismatch between Sil−xGex and Si was observed for the first time in such structures. In contrast to the case of uniaxial stress, the biaxial stress induces a larger strain frequency shift for the LO mode than for the TO mode. The phonon strain shift coefficient for the LO mode was found to be 1010 cm−1, which is larger than most of the values reported in the literatures, and almost composition independent throughout the range of x≤0.27. We argue that the smaller LO strain shift coefficients indicate that the Sil−xGex films used in previous work were partially relaxed.
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References
- 1.
M. A. G. Halliwell, M. H. Lyons, S. T. Davey, M. Hockly, C. G. Tuppen, and C. J. Gibbings, Semicon. Sci. Technol. 4, 10 (1989).
- 2.
D. J. Lockwood and J.-M. Baribeau, Phys. Rev. B45, 8565 (1992).
- 3.
J.C. Tsang, P.M. Mooney, F.H. Dacol, and J.O. Chu, J. Appl. Phys. 75, 8088 (1994).
- 4.
Ran Liu, S. Zollner, M. Liaw, D. O’Meara, and N. Cave, Epitaxy and Applications of Si-Based Heterostructures, MRS Symp. Proc. Vol. 533, pp. 63–68 (1998).
- 5.
P. Yu and M. Cardona, Fundamentals of Semiconductors, (Springer, Berlin, 1995).
- 6.
J.P. Dismukes, L. Ekstrom, and R.J. Paff, J. Phys. Chem. 10, 3021 (1964).
- 7.
For a review see, E. Anastassakis, Acta Physica Hungarica 74, 83 (1994).
- 8.
M.I. Alonso, Ph.D. thesis, University of Stuttgart, 1989 (unpublished).
- 9.
O. Madelung, Semiconductors - Basic Data, (Springer, Berlin, 1996).
- 10.
E. Anastassakis, A. Cantarero, and M. Cardona, Phys. Rev. B 41,7529 (1990).
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Liu, R., Tillack, B. & Zaumseil, P. Raman Characterization of Composition and Strain in Si1−xGex/Si Heterostructures. MRS Online Proceedings Library 591, 260–265 (1999). https://doi.org/10.1557/PROC-591-277
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