Properties of TiN films grown by atomic-layer chemical vapor deposition with a modified gaseous-pulse sequence

The TiN films were grown on p-type Si(1 0 0) and thermal oxide substrates by atomic-layer chemical vapor deposition (ALCVD) using TiCl4 and NH3 as precursors. Two kinds of gaseous-pulse cycles with four-steps and six-steps were adopted. The six-steps ALCVD adds a pump-down step between reactant pulse and purge pulse to improve the removal efficiency of residual reactants and by-products. The results show that the growth rate is about 0.03 nm per deposition cycle, and almost independent of deposition temperature and the pump-down steps. The film resistivity and the Cl residues in TiN films, however, depend on both deposition temperature and pump-down steps. The implementation of pump-down steps into gaseous-pulse cycle effectively lowers the film resistivity and the Cl residues. TiN films with Cl concentration lower than 1 at.% can be obtained at low deposition temperature of 350 °C by the six-steps ALCVD. The relationships between film crystallinity, resistivity, Cl concentration, and process parameters were discussed.