The effects of pressure from 5 torr to 40 torr and the alteration of diluent gas species on the growth rate and structure of deposits have been studied. The experimental results showed that the deposition rate increased with increasing total pressure for a H2 diluent system and decreased for N2. The reactant depletion effect increased especially with an ambient H2 diluent gas. As the diluent gas was added, the deposition rate decreased parabolically, especially for H2 ambient. The theoretical relation between deposition rate and partial pressures of methyltrichlorosilane (MTS) and H2 was in a good accordance with experimental results.

Keywords: CVD, Silicon Carbide, reactant depletion, boundary layer, deposition rate