Layers which had been deposited at low temperatures were found to have expanded and distorted lattices. These were studied by means of  in situ  X-ray diffraction at various temperatures. It was found that annealing at about 450C led to complete lattice relaxation, due to the diffusion of point defects in the lattice. The activation energy for this migration was deduced to be 1.23eV. It was noted that the published activation energy for vacancy diffusion in this nitride was 2.09eV. This suggested that lattice expansion and distortion, in nitride films which were deposited by direct-current magnetron sputtering at temperatures below 200C, was due mainly to atoms on interstitial sites. Also, the density of vacancies was sufficiently high that most of the interstitial atoms found a vacancy with which to recombine. This then led to the observed relaxation.

Activation Energy of Point Defect Diffusion in Low-Temperature Deposited TiN. F.Elstner, H.Kupfer, F.Richter: Physica Status Solidi A, 1995, 147[2], 373-7