Ionized magnetron sputter deposition of hard nanocomposite TiN/amorphous-silicon nitride films

Abstract

Thin films of Ti–Si–N have been deposited by ionized magnetron sputter deposition using separate Ti and Si targets in an Ar/N2 gas mixture. A built-in rf coil generated an inductively coupled plasma close to the substrate. With this setup, the ion flux and energy can be controlled by adjusting the rf power to the coil and the dc substrate bias. Deposition was carried out under various conditions to investigate the effects of different operational parameters on film structure and mechanical properties. Crystallography, grain size, and film texture have been characterized by x-ray diffraction, showing that the addition of Si to TiN films transforms the (111)-oriented structure to a preferred (200)-oriented structure. The nanocrystallite domain size of the TiN, calculated from peak broadening, was found to be less than 10 nm. No signals from crystalline Si3N4 or other phases of titanium silicide were observed. The hardness of the films, measured using nanoindentation, increased to as much as twice that of pure TiN films.