Mechanical strengthening of nanotwinned Cu films with Ag solid solution

• Published in: Materials letters Vol. 313; p. 131775
• Main Authors: Lee, Kang-Ping, Tran, Dinh-Phuc, Chen, Fu-Chian, Hsu, Wei-You, Lin, Yi-Quan, Liu, Hung-Che, Chen, Chih
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.04.2022; Elsevier BV
• Subjects: Annealing; Copper; Diffusion; Diffusion layers; Grain boundaries; Grain Boundary Segregation; Hardness; Heat treatment; Low temperature; Materials science; Metal films; Nanotwinned copper-silver; Silver; Solid solutions; Thin films; Grain boundaries; Nanotwinned copper-silver; Diffusion; Hardness
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2022.131775

[Display omitted] •This study employs Ag solid solution to enhance the mechanical strength of Cu films.•The Ag atoms interdiffused into the nt-Cu films and strengthened them.•The hardness was enhanced by 45.9% using the Ag layer and heat treatment.•This is attributed to Ag diffusion, grain segregation, and twin-spacing reduction. 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.