Microstructure and texture of polycrystalline 3C–SiC thick films characterized via EBSD

Cubic silicon carbide (3C-SiC) is an excellent protective film on graphite and has been fabricated via laser chemical vapor deposition (LCVD) with an extremely high deposition rate by our research group. To understand comprehensively its growth behavior, the polycrystalline 3C-SiC thick films with the preferred orientation of < 111 > and < 110 > were characterized by diverse measurements, especially electron back-scatter diffraction (EBSD). Along the growth direction of the < 110 >-oriented 3C-SiC, the microstructure changed from equiaxed grains to elongated grains with < 111 > orientation, and eventually the < 110 >-oriented columnar grains. The stacking faults in the < 110>-oriented 3C-SiC could be marked as < 11-20 >-oriented 6H-SiC. On the other hand, in the < 111 >-oriented 3C-SiC films, the microstructure changed from mainly equiaxed grains to large columnar grains. The high-density stacking faults in < 111 >-oriented 3C-SiC films may lead to the identification of the nominal 2H, 4H and 6H polytypes by Raman spectra and EBSD. The (0001) planes of 2H-, 4H-SiC are perpendicular to the growth direction, while that of 6H-SiC are parallel.