Raman scattering has been used to characterize ultrathin films of β-SiC, ranging in thickness from 38 nm to 240 nm. These films were prepared on the surface of a <100> Si substrate by a carbonization process at a temperature of 1300°C. In each case, the LO phonon near 970 cm−1 and the TO phonon near 795 cm−1 are observed, indicating the formation of β-SiC crystal. The Raman linewidths and peak positions indicate evidence of nonuniform stress and disorder. The Raman intensity of the TO phonon is nearly twice the intensity of the LO phonon measured both with and without the Si substrate, which indicates that the crystal growth was not entirely confined in the <100> direction.