Investigation of Ti/TiN multilayered films in a reactive mid-frequency dual-magnetron sputtering

Abstract

Influence of the process parameters like (i) sputtering gas pressure, (ii) target current, (iii) substrate bias voltage and (iv) substrate temperature of a reactive mid-frequency dual-magnetron sputtering on (a) surface defects and (b) mechanical properties of Ti/TiN multilayered films was investigated. The forming mechanisms of the observed droplets and craters were analyzed. Results showed when: (1) pressure of Ar/N2 gases PAr/N2 was at 0.31Pa and substrate temperature was in certain range, the size and the density of the surface defects on the TiN films tended to decrease with increasing the target current and the pulsed bias voltage; (2) the optimal deposition parameters for accomplishing fewer surface defects were used, increasing the thickness of the Ti buffer layer decreased the microhardness in certain level, and the adhesion was firstly increased and then decreased as thickness reaching and/or beyond a critical value. Results also showed that selection of optimized process parameters evidently minimized the surface defects and improved the mechanical properties of the film.