Structural Identification of SiC Polytypes by Raman Scattering: 27R and 33R Polytypes

Abstract

Raman scattering spectra of SiC polytypes 27R and 33R have been measured with a back scattering geometry using a (0001) face. The relative Raman intensities of folded modes in transverse acoustic (TA) and transverse optic (TO) branches have been calculated with the aid of a linear chain model. The calculated Raman profile for each branch agrees semi-quantitatively with the observed spectrum. The result indicates that the Raman intensity analysis of the folded modes can be used to identify the polytype of SiC with longer period.