STUDY OF DEFECTS IN THIN TITANIUM FILMS BY POSITRON-ANNIHILATION SPECTROSCOPY

The positron lifetime technique has been used for studying the defect structure of titanium (Ti) thin films obtained by d.c. magnetron sputt ering on Ti substrates. It was found that for non-annealed samples lar ge voids exist in the Ti films. Sample annealing for 1 h at 450 degree s C leads to a decrease of the void concentration. By checking the lin earity of the valence annihilation parameter S versus the core annihil ation parameter W we have shown that the type of the defects in the fi lms of different thickness is the same. Comparison of the characterist ic slope R(d) for non-annealed and annealed samples demonstrates that annealing changes the defect types in the films.