Activation Energy of Point Defect Diffusion in Low-Temperature Deposited TiN

Abstract

Low-temperature deposited titanium nitride layers exhibiting increased and distorted lattices are subjected to in situ X-ray diffraction investigations at different temperatures. Annealing at about 450 °C leads to a complete lattice relaxation due to diffusion of point defects in the lattice. The activation energy for this diffusion can be calculated to be 1.23 ± 0.07 eV (while the reported activation energy of vacancy diffusion in TiN films is 2.09 eV). This proves that lattice widening and distortion in titanium nitride films deposited by dc magnetron sputtering at temperatures below 200 °C is mainly due to atoms on interstitial sites, and that the density of vacancies is high enough that most of the interstitial atoms find a vacancy to recombine, which leads to the observed relaxation.