Manipulating the thermal stability of the {111}-oriented nanotwinned Ag films by ion bombardment

Abstract

Materials with nanotwinned structures have been known to possess high strength, high ductility, and low resistivity. Tailoring their mechanical and thermal stabilities has become a critical technique based on their practical applications in the electronic industry. In this study, we propose to manipulate the thermal stability of the nanotwinned Ag thin films with the assistance of ion bombardment. The {111}-oriented nanotwinned Ag films were fabricated on Si (100) substrate with 100 nm-thick Ti adhesion layer using different applied ion bombardment energies. We found that the thermal stability of highly {111}-oriented nanotwinned Ag films can be tailored by using different levels of ion bombardment during deposition. The sample with the highest ion bombardment energy exhibits exceptional thermal stability, which can sustain {111}-oriented nanotwinned structure and high mechanical strength after 450 °C annealing. On the other hand, the {111} to {100} texture transformation with large grain coarsening can be triggered at low temperature of 150 °C without introducing ion bombardment during the deposition. This study not only advances the fundamental understanding of the thermal stability of the nanotwinned Ag films after high-temperature annealing but also provides valuable insights into manipulating the thermal stability of sputtered nanostructured Ag films through ion bombardment based on the demands of their applications.