Elastic Properties Study of Si/Ge Superlattices by Brillouin Light Scattering Spectroscopy

✍ Scribed by de Bernabé, A; Prieto, C.

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 290 KB
• Volume: 25
• Category: Article
• ISSN: 0142-2421
• DOI: 10.1002/(sici)1096-9918(199705)25:5<324::aid-sia239>3.0.co;2-r

✦ Synopsis

The elastic properties of Si/Ge strained-layer superlattices have been studied by means of Brillouin light scattering spectroscopy in order to verify the validity of the most reliable explanations for the so-called "supermodulus e †ectÏ. The superstructures, grown along the [ 001 ] direction, have composition modulation wavelengths ranging from 1.4 to 5.6 nm and Si/Ge ratios 1/1, 3/1, 4/1 and 1/4. The study has been carried out in three di †erent stages : a check of the non-inÑuence of the substrate on the determination of the elastic properties ; the angular dependence of the surface sound velocity within the surface plane ; the variation of the phase velocity with the modulation wavelength. No evidence of the anomalous supermodulus e †ect has been found in these superlattices, which can be explained on the basis of the latest theoretical predictions. In addition, the obtained data of hypersonic surface waves are in good agreement with previous results reported in Si and Ge pure single crystals.

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