Elementary steps and application of the CVD of SiC/BN double layers

Thermal decomposition mechanisms of Methyltrichlorosilane MTS and Trimethylborate has been studied by online gas chromatography and in situ infrared spectroscopy. These precursors are used to deposit SiC or BN mono layers and double layer systems by CVD on multifilament substrates. The knowledge of existing gas phase reactions and deposition mechanisms is fundamental to online process control. Our investigations led to some new mechanistic notions. The reactions taking place at the CVD of silicon carbide can be divided in four parts: initial decomposition of Methyltrichlorosilane, silicon pathway, carbon pathway, and surface reactions. The initial step is suggested without formation of radicals. First investigation on Trimethylborate were carried out with respect to dependence of layer composition from process parameters.