Infrared ellipsometry of SiC/Si heterostructures with Ge modified interfaces

Cubic silicon carbide films grown heteroepitaxially by solid source molecular beam epitaxy on silicon with one monolayer of germanium predeposited on silicon at different temperatures prior to the carbonization were investigated with infrared ellipsometry, Fourier transform infrared reflection measurements and atomic force microscopy. From the infrared ellipsometry, the phonon frequencies extracted from the fitting results were lower then the phonon frequencies for single crystalline material. This is due to tensile stress in the grown SiC layers. A similar behavior was found in the case of Fourier transform infrared reflection measurements. With increasing germanium predeposition temperature the determined phonon frequencies shifts to higher values indicating on a stress reduction in the heteroepitaxial system