Skip to main content Accessibility help

Epitaxial CoSi2/Porous-Si Strained Layer Structres Grown by Mbe

  • Y. C. Kao (a1), D. Jamieson (a2), G. Bai (a2), C. W. Nieh (a2), T. L. Lin (a1) (a3), B. J. Wu (a1), H. Y. Chen (a1) and K. L. Wang (a1)...


CoSi2 epitaxial layers with thickness ranging from 24 nm to 170 nm have been grown onto porous Si substrates by molecular beam epitaxy. The X-ray rocking curves and transmission electron microscopy (TEM) are used to examine the strain relaxation and interface quality. Backscattering with channeling is used to characterize the crystallinity of the epilayers. The results show that it is necessary to grow a thin buffer Si layer in order to improve the interfacial sharpness and crystallinity of the epilayers; near perfect crystallinity is then obtained as the thickness of the CoSi2 films exceed 50 nm. TEM results reveal that both CoSi2/Si and CoSi2/porous-Si interfaces are flat and layer thickness is uniform. It is found by TEM that the dislocation density of CoSi2 grown on porous Si is much lower than that on single-crystal Si. For thin CoSi2 grown on porous Si, the TEM and strain measurement results imply that part of the film is pseudomorphic where no dislocations are observed. Average strains of CoSi2 films grown on porous Si substrates with thicknesses greater than 30 nm show a lower strains comparing to that on crystalline Si. This suggests that by using porous Si as substrates the stress energy in the epilayer can be accommodated by the Si buffer layer that bridged over the trenches of porous Si.



Hide All
1. Tang, R., Poate, J., Bean, J., Gibson, J., and Jacobson, D., Thin Solid Films, 93, 77 (1982).
2. Kao, Y. C., Tejwani, M., Xie, Y. H., Lin, T. L., and Wang, K. L., J. Vac. Sci. Technol., B3(2), 596 (1985).
3. Jamieson, D., Bai, G., Kao, Y. C., Nieh, C. W., Nicolet, M-A., and Wang, K. L., to be presented in Mat. Res. Soc. Spring meeting, 1987.
4. Luryi, S. and Suhir, E., Appl. Phys. Lett. 49, 140 (1986).
5. Ishizaka, A., Nakagawa, K., and Shiraki, Y., Proceeding of Conference on Molecular Beam Epitaxy and Clean surface Techniques (Japanese Society of Applied Physics, Tokyo, Japan, 1982), p. 183.
6. Unagami, T., Jpn, J. Appl. Phys. 19, 231 (1980).
7. Lin, T. L., Chen, S. C., Kao, Y. C., and Wang, K. L., Appl. Phys. Lett. 48, 1793 (1986);
Tabe, M., Jpn. J. Appl. Phys. 21, 534 (1982).
8. Speriosu, V. S., and Vreeland, T. Jr., J. Appl. Phys. 56, 1591 (1984).
9. Kao, Y. C., Wang, K. L., de Fresart, E., Hull, R., Bai, G., Jamieson, D., and Nicolet, M-A., J. Vac. Sci. Technol. (in press)


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed