X-Ray Absorption Studies of Strain in Epitaxial (Si-Ge) Atomic Layer Superlattice and Alloy Films

Authors

T. Tyliszczak, McMaster UniversityFollow
A. P. Hitchcock, McMaster University
Z. H. Lu, National Research Council, Ottawa
J. -M. Baribeau, National Research Council, Ottawa
T. E. Jackman, McMaster University

Abstract

The Si 1s (K-shell) X-ray absorption spectra of a series of strained Si_xGe_100-x alloy thin films and several {(Si)_m(Ge)_n}_p atomic layer superlattices (ALS) grown epitaxially on Si(100) and Ge(100) substrates have been investigated using plane polarized synchrotron radiation. Polarization dependent components of the signal are attributed to anisotropic states associated with strain-induced tetragonal distortions. The sense of the polarization is shown to be identical for all compositions (x = 25 to 92) of SiGe alloys grown on Si(100) substrates. The opposite polarization dependence is found to occur for all Si_xGe_100-x alloys (x = 12 to 50) grown on Ge(100) substrates. The polarization dependence and shape of the near edge spectral features of alloy and ALS samples which have similar (average) chemical composition are remarkably similar. A preliminary comparison of the alloy results with literature band structure calculations is made.

Recommended Citation

Tyliszczak, T.; Hitchcock, A. P.; Lu, Z. H.; Baribeau, J. -M.; and Jackman, T. E. (1994) "X-Ray Absorption Studies of Strain in Epitaxial (Si-Ge) Atomic Layer Superlattice and Alloy Films," Scanning Microscopy: Vol. 8: No. 4, Article 5.
Available at: https://digitalcommons.usu.edu/microscopy/vol8/iss4/5