Preparation of amorphous Si3N4-C plate by chemical vapour deposition

Chemical vapour deposition of a Si-N-C system has been studied by using SiCl₄, NH₃, H₂ and C₃H₈ as source gases at deposition temperatures (T _dep) of 1100 to 1600° C, and total gas pressures (P _tot) of 30 to 100 torr. To control the amount of carbon in these deposits the propane gas flow rate FR(C₃H₈)] was varied from 0 to 200 cm³ min^–1. Homogeneous plate-like amorphous deposits were successfully prepared atT _dep=1100 to 1300° C,P _tot=30 to 70 torr andFR(C₃H₈)=25 to 100 cm³ min^–1. The deposits were composed of amorphous silicon nitride and carbon and the carbon content increased up to 10 wt% with increasingFR(C₃H₈). The surfaces of the deposits had a pebble-like structure.