Preferred orientation of chemical vapor deposited polycrystalline silicon carbide films

We investigated the mechanism that determines the preferred orientation of polycrystalline silicon carbide (SiC) films prepared by CVD from a mixture of dichlorodimethylsilane (DDS) and He. X-ray diffraction (XRD) measurements indicated that the major growth direction is either the (220) or the (111) plane. We developed a numerical model for predicting the preferred orientation, assuming Langmuir-type adsorption and reaction of the growth species. This model suggests that the (111) plane appears under reaction-limited deposition, while the (220) plane appears under adsorption-limited deposition. Our experimental and numerical results show good qualitative agreement with experimental results for films prepared from methyltrichlorosilane (MTS) and H₂.