Effects of substrate bias on nanocrystal-(Ti, Al)Nx/amorphous-SiNy composite films

Abstract

Nanocrystal-(Ti, Al)Nx/amorphous-SiNy composite films were prepared in a codeposition process under different substrate bias voltages. The effects of substrate bias voltage on the deposition rate, composition, microstructure, and mechanical properties of nanocomposite films were investigated. Results indicated that the films with bias voltages caused resputtering due to the bombardment of high-energy ions on film surface. The resputtering effect had substantial influence on deposition rate, surface morphology, and composition of films. The films with (220) preferred orientation were also observed as the applied substrate bias voltages exceeded 50 V. As the substrate bias voltage increased, the nanocrystallite size increased, lattice strain raised, and the hardness decreased.