From the previous study, we established that crystalline r-B4C grows on both the C-face and Si-face of 4H-SiC. The r-B4C film grown on the Si-face has a faceted surface morphology (Fig. ), while the surface morphology of the film grown on the C-face appears to consist of individual columns separated by voids (Fig. ). The cross-section in Fig shows a dense film on the Si-face, while the cross-section in Fig. shows discernable voids, emphasized by dotted lines in the figure, that extend almost to the film/substrate interface. The cross-sections show that a thicker film, around 2 µm, grows on the Si-face (Fig ), as compared to a thinner film, around 0.9 µm, grows on the C-face (Fig. ).