Variable-Energy Positron Studies of Vacancy-Type Defects in TiN Films on Si

A variable-energy (0–30 keV) positron beam has been used as a nondestructive probe for titanium nitride (TiN) films with a thickness of 800 nm deposited on Si substrates by a reactive sputter deposition in a DC-planar-magnetron-type apparatus. Doppler broadening profiles of positron annihilation radiation are measured as a function of incident positron energy. It is found that the density of titanium vacancies depends on the concentration of titanium in the TiN film. Titanium vacancies are abundant in the titanium-deficient TiN film. The precipitation of metallic titanium is not involved in the specimens.