Investigation of magnetron-sputtered titanium nitride films using positron annihilation spectroscopy

Positron annihilation spectroscopy in conjunction with a variable-energy beam has been used to investigate the variation of the vacancy-type defect density of titanium nitride films with varying nitrogen concentrations. Decreases in the Doppler-broadened lineshape parameter were observed as the nitrogen partial pressure used in the manufacture of the samples was increased from 0.01 Pa to 0.1 Pa indicating a decrease in the positron trapping at vacancy defects in this range. It is suggested that the positrons are trapped in Ti vacancies with the variation in trapping being due to increasing N-atom migration onto Ti sublattice vacancy sites as the nitrogen partial pressure is increased.