SAXS analysis of the effect of H2 dilution on microstructural changes of HWCVD deposited a-SiC : H

Hydrogenated amorphous silicon carbon (a-SiC : H) films were deposited by hot wire chemical vapor deposition (HWCVD) and their porosity was investigated by small-angle X-ray scattering (SAXS), XRR and FTIR. SAXS measurement was analyzed by Guiner plot, Porod plot, Debye plot and scaling factor. The measurement of the SAXS results assumed a distribution of spherical pores. This analysis suggested that the maximum of pore size distributions occur for radius of gyration of 5–6 Å. As the H2 flow rate increases, the pore size distribution narrows and the volume occupied by the pores decreases. A direct relation between the atomic density of a-SiC : H films deposited by HWCVD and the pore volume fraction was also obtained. The low scattering intensity observed for the films deposited by HWCVD showed that they were compact and homogeneous regardless of the H2 dilution.