| Autor: |
Perova, T. S., Wasyluk, J., Lyutovich, K., Kasper, E., Oehme, M., Rode, K., Waldron, A. |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; Feb2011, Vol. 109 Issue 3, p033502, 11p, 1 Diagram, 4 Charts, 9 Graphs |
| Abstrakt: |
Micro-Raman spectroscopy was employed for the determination of the germanium content, x and strain, [variant_greek_epsilon], in ultrathin SiGe virtual substrates grown directly on Si by molecular beam epitaxy. The growth of highly relaxed SiGe layers was achieved by the introduction of point defects at a very low temperature during the initial stage of growth. SiGe virtual substrates with thicknesses in the range 40-200 nm with a high Ge content (up to 50%) and degree of relaxation, r, in the range 20%-100% were investigated using micro-Raman spectroscopy and x-ray diffraction (XRD) techniques. The Ge content, x, and strain, [variant_greek_epsilon], were estimated from equations describing Si-Si, Si-Ge, and Ge-Ge Raman vibrational modes, modified in this study for application to thin SiGe layers. The alteration of the experimentally derived equations from previous studies was performed using independent data for x and r obtained from XRD reciprocal space maps. A number of samples consisting of a strained-silicon (s-Si) layer deposited on a SiGe virtual substrate were also analyzed. The stress value for the s-Si varied from 0.54 to 2.75 GPa, depending on the Ge-content in the virtual substrates. These results are in good agreement with theoretically predicted values. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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