Raman Scattering on SiC Polytypes —Probe for Evaluation of the Lattice Vibrational Amplitudes—

Abstract

Long period SiC polytypes exhibit a number of Raman bands which reflect their stacking sequence of atomic planes. The Raman spectra of these polytypes can provide information on the phonon frequencies and vibrational amplitudes in the basic polytype (cubic, zincblende structure). Assuming a zincblende type structure as an approximate structure of SiC polytypes, the relative Raman intensity of folded modes in two SiC polytypes is calculated with several models of lattice dynamics and compared with the observed spectra. In the framework of a simple bond-polarizability model we show how the analysis of intensities can be used to rate different phenomenological models.