SiC epitaxial mesa structures have been grown on 4H-SiC (0001) and (11 (2) over bar0) substrates using a carbon mask for mesa growth. The carbon mask can be removed by thermal oxidation without surface degradation, resulting in the successful formation of SiC epitaxial mesa structures on SiC substrates. The lateral growth on the carbon mask was observed along the <11 (2) over bar0> direction on off-axis (0001) and along the <0001> direction on (11 (2) over bar0) substrates. On the off-axis (0001) substrate, 3C-SiC inclusion was detected by Raman scattering on the SiC mesa structure at the upside of [11 (2) over bar0] off-direction. On the (11 (2) over bar0) substrate, 3C-SiC growth also occurred in the part of lateral growth along the <0001> direction, which was examined by XTEM.