Low Resistance and High Electromigration Lifetime of Cu-To-Cu Joints Using (111)-Oriented Nanotwinned Copper Low Resistance and High Electromigration Lifetime of Cu-To-Cu Joints Using (111)-Oriented Nanotwinned Copper
1Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan 30010, ROC
2Department of Materials Science and Engineering, University of California at Los Angeles, Los Angeles, California 90095, USA
Adv. Mater. Lett., 2021, 12 (8), 21081654
Publication Date (Web): Jul 05, 2021
Copyright © IAAM-VBRI Press
Cu-to-Cu joints of 30 mm in diameter were fabricated using (111)-oriented nanotwinned copper at 300 °C for 20 min in N2 ambient. The joints possess excellent electrical properties. The average resistance and specific contact resistivity are 4.1 mΩ and 3.98 × 10-8 Ω·cm2, respectively for an as-fabricated Cu joint. With a second step annealing at 400 °C, the resistance can be reduced to 3.27 mΩ due to grain growth across the joint interface. There is 50% resistance reduction compared to SnAg solder joints with the same diameter. The electromigration lifetime for Cu-to-Cu joints is at least 750 times longer than solder joints.
Cu-to-Cu direct bonding, nanotwinned Cu, grain growth, electromigration, resistance.