This study employs Ag solid solution to enhance the mechanical strength of nanotwinned copper (nt-Cu) films. We deposited a thin silver layer onto the nt-Cu film and annealed it at low temperatures. Depth profile reveals that Ag atoms diffused 100 nm after annealing. The Ag atoms interdiffused into nt-Cu film and strengthened it. A significant enhancement in hardness (45.9%) was obtained using the Ag layer and heat treatment. This could be attributed to the Ag diffusion, grain boundary segregation, and twin density increase. The study delivers a pioneer approach to strengthen the nt-Cu films.
- Grain boundaries
- Nanotwinned copper-silver