Raman analysis of a crystalline SiC sample prepared from carbon-saturated melt of silicon

Crystalline SiC samples were prepared in solidification of silicon melt sat urated by carbon solved from the inner wall of a graphite crucible. The cry stalline structure of the samples was analysed in Raman spectroscopy and co nfirmed as 3C-SiC both in x-ray diffraction and x-ray photoelectron spectro scopy (XPS). The Raman spectra of the samples present a strong sharp peak l ocated at 796.3 cm(-1) with a full width at half maximum about 6 cm(-1) and three weak peaks broadened around 1525.6, 1631.4 and 1719.1 cm(-1), respec tively. The former belongs to the transverse optical phonons of 3C-SiC, whi le the latter can be attributed to the second-order scattering. However, th e longitudinal optical mode of 3C-SiC has not been found for our samples. A n additional broadened peak at 532.2 cm(-1) may imply the existence of some lattice defect in the samples, which is related to nitrogen introduced uni ntentionally into the lattice in the growth process and confirmed in XPS of N 1s binding energy centred at 400.9 eV.