Raman scattering study on phonon anisotropic properties of SiC

Abstract

Phonon anisotropic properties of 4H, 6H and 15R-SiC were investigated by polarization Raman scattering, and Raman selection rules were explored both theoretically and experimentally. As a function of the relative angles between the incident and the scattered light, Raman intensity of E1, E2 and A1 modes were collected from the (0001) plane, the (11¯00) plane, and the (112¯0) plane of wurtzite SiC and the 15R-SiC region in the (0001) plane. Results showed that E1, E2 and A1 modes were anisotropic in the (112¯0) and the (11¯00) planes of 4H and 6H-SiC, while E2 modes were isotropous in the (0001) plane. Furthermore, E1 mode of 799 cm−1 in the (0001) plane appeared and exhibited anisotropic properties due to the stacking faults in SiC. Otherwise, the anisotropic properties of A1 and E modes of 15R-SiC in the (0001) plane were in agreement with that of wurtzite SiC.