Kinetics and microstructure of TiN coatings by CVD

Titanium nitride (TiN) coatings obtained by chemical vapor deposition with TiCl4, H2, and N2 as gas sources at the atmospheric pressure have been examined in this study. The results showed that the deposition rate increased and reached a saturated value with increasing TiCl4 partial pressure at different process parameters including deposition temperatures and partial pressures of H2 and N2. The reaction orders of TiCl4, H2, and N2 were extracted by the least-square regression approximation of the experimental data. For TiCl4 on N2, their reaction order is influenced by the partial pressure of the other. A degraded growth rate at a high temperature of 1200°C was mainly related to the endothermic CVD TiN reaction and the hot-wall reactor. Microstructural examination by scanning electron microscope revealed the surface morphology changed with process parameters. Compositional analysis of the CVD TiN showed non-stoichiometric at low temperatures and 1200°C, but stoichiometric at 1000°C. The TiN stoichiometry could be affected by the partial pressures of N2 and H2.