Improvement of Ag films with highly (111) surface orientation for metal direct bonding technique: Nanotwinned structure and ion bombardment effect

High-density nanotwinned structure are introduced into Ag films with over 95% of (111) surface orientation. Different substrate biases were applied to the nanotwinned Ag films during the deposition process in order to optimize the nanostructure and properties of nanotwinned Ag films, while maintain the strong (111) surface orientation. The formation of undesirable transition region, which is consisted of random-oriented nanocrystalline...