Optical and material properties of sandwiched Si/SiGe/Si heterostructures

Si1−xGex layers sandwiched between Si were grown at low temperature of 450 °C by molecular beam epitaxy. A comprehensive characterization has been performed on these heterostructures by multiple techniques, including X-ray diffraction (XRD), photoluminescence, Raman scattering, Fourier transform infrared (FTIR) spectroscopy, Rutherford backscattering spectrometry (RBS), ion channeling and secondary ion mass spectroscopy (SIMS). XRD confirmed the single crystallinity and the (100) orientation of the Si1−xGex layer. The Ge compositions and layer thicknesses were precisely determined by RBS. FTIR measurements revealed the vibration modes of Si–O–Si from the oxidation on surface and Si–H due to the hydrogenization during growth.