A flow-modulated carbonization process is applied to grow a 3C-SiC thin film of high crystal quality on the Si (1 0 0) substrate using low pressure chemical vapor deposition. The flow-modulated carbonization was performed by flowing intermittent carbon-based precursor. The crystal quality of the so-obtained 3C-SiC is compared with that fabricated via the conventional carbonization process, using X-ray diffractometry and Raman spectra data, indicates a better crystal quality using this flow-modulated carbonization process. Moreover, Si out-diffusion from Si substrates is suppressed in the flow-modulated carbonization process, resulting in a reduced density of voids. Consequently, the flow-modulated carbonization process plays an active role in enhancing the crystal quality and reducing the void formation. This is the first report of the heteroepitaxial growth of 3C-SiC layers using the flow-modulated carbonization process.