Influence of Stacking Disorder on the Raman Spectrum of 3C-SiC

Abstract

We measured Raman spectra of as-deposited and laser-annealed polycrystalline 3C-SiC layers. Compared to single crystal 3C-SiC the Raman lines are considerably broader and an additional signal at frequencies corresponding to a high density-of-states is found. We discuss the influence of stacking disorder on the Raman spectrum by comparing our results with computer simulated Raman intensity profiles of one-dimensionally disordered SiC structures. The broadening of the linewidth and the disorder-induced peak shift, as well as the density-of-states feature can be explained with stacking disorder. After laser annealing above 1900 K the Raman lines narrow irreversibly and the density-of-states feature disappears. We ascribe both observations to a reduction of stacking disorder.