Purity Evaluation of Highly Oriented Cubic Silicon Carbide Using Micro-Raman Spectroscopy

The purity level of 3C-SiC (β phase) powder is an important factor for its use as a raw material for fabricating high-quality single crystals. Herein, we used micro-Raman spectroscopy to systematically investigate the purity of 3C-SiC powders subjected to three different purification treatments. The transverse optical (TO; 795 cm −1 ) and longitudinal optical (LO; 970 cm −1 ) phonon modes of 3C-SiC were measured, and the peak intensity ratio (TO/LO) showed good correlation with the purity. The highly purified 3C-SiC had a TO/LO value of 1.0 at a narrow full width half maximum of the LO peak. Furthermore, the pristine 3C-SiC powder exhibited Raman peaks corresponding to the D and G bands, indicating carbon bonding by graphite impurities. Thus, we demonstrated that the proposed micro-Raman spectroscopy is an effective analysis technique for characterizing the crystal quality and purity level of 3C-SiC powders.