Characterization of 3C-SiC epitaxial layers on TiC(111) by Raman scattering

3C-SiC epitaxial layers of 0.3-4 mu m thickness deposited on TiC(111) have been investigated by Raman microprobe. Relatively thick layers showed TO-and LO-phonon bands with peak frequencies higher than those of bulk reference by about 5.8 cm(-1) and 3.6 cm(-1), respectively. This frequency upshift is due to residual stress in the epi-layers. The in-plane, compressive, biaxial stress is estimated to be 1.7 GPa, and there are 0.24% in-plane compressive strain and 0.10% tensile strain in the normal direction. The in-plane strain is 2-3 times smaller than those expected from the lattice mismatch, or from the difference in thermal expansion coefficient between the epi-layer and the substrate. In spite of a small lattice mismatch between 3C-SiC and Tie, the residual in-plane stress is larger than that reported for SC-SIG on Si which has much larger lattice mismatching.