A study comparing SiO(2) and Si(3)N(4) masks for selective epitaxial growth of 3C-SiC films on Si wafers using a HCl-free APCVD process is reported. Selective growth of SiC films using SiO(2) masks can be achieved, but the microstructure of the SiC films in the unmasked Si areas is polycrystalline. In addition, delamination of the SiO(2) mask was often observed. For dry-etched Si(3)N(4) masks, heteroepitaxial growth of 3C-SiC can be achieved inside the unmasked regions, but deposition of polycrystalline SiC on the mask was also observed. Selective epitaxial growth of 3C-SiC films was obtained using wet-etched Si(3)N(4) masks. No delamination was found on these masks; however, holes and polycrystalline structures were found in regions where lateral overgrowth fronts converge.