High-speed homoepitaxy of SiC from methyltrichlorosilane by chemical vapor deposition

Silicon carbide was deposited homoepitaxially at high growth rates (up to 90 μm/h) with methyltrichlorosilane (MTS) as the precursor in chemical vapor deposition. The substrates were 6H- and 4H-SiC (0 0 0 1) wafers with different misorientation (<0.5°, 3.5° and 8°) tilts toward (112¯0). At a growth temperature of 1400 °C, the grown film was composed of faceted grains and the surface was very rough. As the growth temperature increased, the crystal grains were enlarged and the films' surfaces became smoother and smoother. At 1600 °C, on 8° misoriented substrate, a very smooth film with mirror-like surface was generated. Raman spectroscopy showed that the polytypes of the films were affected by the substrate misorientation. When the 6H-SiC substrates were well oriented, i.e. with the offset angle of less than 0.5°, 3C-SiC was deposited with numerous triangular stacking faults (TSFs). When the offset angle of substrates was 3.5°, mixtures of 3C- and 6H-SiC polytypes were deposited. When the offset angle was 8°, the epitaxial growth perfectly replicated the substrates' polytypes, i.e. high-quality 6H- and 4H-SiC epilayers were generated on the 6H- and 4H-SiC substrates, respectively. The full-width half-maximum (FWHM) of X-ray diffraction rocking curves for the c-plane of pure smooth 6H- and 4H-SiC layers was in the range of 15-20 arcsecs. Photoluminescence (PL) confirmed the polytypes of 6H- and 4H-SiC layers: Both exhibited clear near-band edge emission at room temperature. These results demonstrate that MTS is a suitable precursor for the rapid, high quality SiC epitaxy.