Strain in a single ultrathin silicon layer on top of SiGe islands: Raman spectroscopy and simulations
| E. Bonera, F. Pezzoli, A. Picco, G. Vastola, M. Stoffel, E. Grilli, M. Guzzi, A. Rastelli, O. G. Schmidt, L. Miglio Phys. Rev. B 79, 075321 (2009) URL PDF |
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| Abstract | ||
| By means of resonant Raman spectroscopy we investigated the strain on a single ultrathin crystalline silicon layer, locally induced by buried SiGe nanostructures. The spectrum of a 5-nm-thick silicon layer on top of SiGe islands shows a single highly strained feature attributed to the out-of-plane phonon. The direct comparison of the experimental results with finite-element methods through spectral simulation shows excellent agreement that clarifies the physical origin of the spectrum. An increase in the silicon layer thickness up to 40 nm results in a progressive reduction in the strain. |