Formation of epitaxial 3C-SiC layers by microwave plasma-assisted carbonization

Epitaxial 3C-SiC (β-SiC) thin layers are grown on Si (001) substrates by carbonization in moderate-pressure microwave plasmas, typically used for diamond film deposition. The substrate temperature and the CH4 gas concentration diluted in H2 gas are varied from 1000 to 1200 °C and from 2 to 8 vol.%, respectively. The grown layers are characterized by scanning electron microscopy, Raman spectroscopy, x-ray diffraction, Fourier transform infrared spectroscopy, reflection high energy electron diffraction, and energy-dispersive x-ray spectroscopy. For 2% CH4, epitaxial 3C-SiC about 10 nm thick is grown only when the temperature is increased to 1200 °C, while polycrystalline 3C-SiC is grown for temperatures less than 1200 °C. For 8% CH4, epitaxial 3C-SiC is grown even for temperatures less than 1200 °C, but the thickness of the SiC layer is reduced. Some amounts of amorphous carbon and diamond phases are found to grow on the SiC layers.