Nanocrystalline silicon (nc-Si) embedded a-SiC:H films were deposited by hot-wire chemical vapor deposition (HWCVD) using SiH 4 , CH 4 and H 2 gas precursors. The films were characterized by small-angle X-ray scattering, X-ray diffraction (XRD) and Raman spectroscopy to analyze their structural and fractal nature. The analysis of a-SiC:H films indicated the scattering from mass fractal aggregates of amorphous and nanocrystalline domains of nano-Si. The XRD results indicated that the size and crystallite fraction of nanocrystallites decreased with increasing CH 4 flow rate. Nc-Si changed from the mass fractal to the surface fractal with increasing CH 4 flow rate. The inter-diffusion correlation length between nc-Si embedded a-SiC:H varies from 2.4nm to 5.7nm with a CH 4 flow rate.