The effects of initial gas composition and pressure on the growth behavior of CVD SiC films

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.