Improvement of mechanical properties of Ti/TiN multilayer film deposited by sputtering

Advanced functional (multi-layer) coatings, were conducted by r.f. magnetron sputtering. Ti–TiN multi-layer coatings were deposited on a silicon (100) by using multi cathodes. The total thickness was kept at 150 nm and the number of layers was changed from 4 to 40. The relief of internal stress in a film, which causes breaking of the film, and formation of a preferred orientation of the film by increasing the number of layers, was confirmed by measurements of scratching, nano-indenting tests and XRD. These phenomena were explained by minimization of total energy composed of interface and strain energies. The preferred orientation was predicted to change from (111) to (100) with increasing layer number, and XRD produced the expected result.