Single crystalline Si with buried porous layers was utilized as a substrate for the epitaxy of 100-nm -thick Si0.73 Ge0.27. Raman spectroscopy revealed that the strain status in SiGe systematically changes according to the variation in the porosity of the substrate and that the strain relaxation in SiGe was found to proceed with increasing porosity. Furthermore, Si was found to be tensilely strained to reduce the compressive strain in SiGe. These results suggest that the appropriate design of the porosity and the thickness of the thin Si layer on the buried porous layer offers an alternative way to control strain status in SiGe.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)