This paper discusses the growth and characterization of 3C-SiC films on Si (100) and (111) substrates using hexamethyldisilane (HMDS) as the source material in a resistance-heated furnace as well as the formation and microstructure of various types of unusual defects. Apart from common triangular and square voids, some unusual shaped voids like hexagonal, truncated octahedron, etc. and some irregular features (like hockey stick or pipes) were observed regularly, which are related to voids. SiC whiskers and wires with a wide range of diameters (nm to μm) were formed inside cracked regions as well as within voids. Optical microscopy, scanning electron microscopy (SEM) and Raman spectroscopy were used to study these features.