Preparation of SiC whiskers deposited by CVD process

SiC whiskers were deposited on RB-SiC substrate in a hot-wall chemical vapor deposition furnace, using methyltrichloride silicane (MTS) as precursor gas, H₂ as carrier gas and argon as dilute gas, at 1100°C and 1150°C respectively. The effects of deposition temperature and dilute gas on the morphology of deposits were studied. The morphologies and composition of the deposits were determined by scanning electron microscope (SEM) and X-ray diffraction (XRD) respectively. As a result, the deposits at 1100°C are composed of whiskers and the deposits at 1150°C are of whiskers and grains. The mean diameter of the whiskers increases with the rise of the temperature between 1100°C and 1150°C. With the addition of dilute gas, the number of the curly defects of whiskers at 1100°C and grains in the deposits at 1150°C decrease. The as-obtained whiskers at 1100°C are determined as β-SiC. Furthermore, the growing mechanism of the deposits and the reason of the variation of morphologies were explained theoretically.