Nanostructuring enforced sandwich-tubular CNT-Cu interconnects. (15th December 2021)

• Record Type: Journal Article
• Authors: Wang, Pengjie; Cao, Qiang; Lan, Yucheng; Zhu, Hanxing; Liu, Sheng; Peng, Qing
• Is Part Of: Composite structures. Volume 278(2021)
• Publication Date: 2021-12-15
• Subjects: CNT-sandwiched nanocomposite -- Mechanical behaviors -- Young's modulus -- Tensile toughness -- Nanointerconnects; Composite construction -- Periodicals; Composites -- Périodiques; 624.18
• DOI: 10.1016/j.compstruct.2021.114705
• Languages: English
• ISSNs: 0263-8223

Abstract

Graphical abstract: Highlights: Enhancement for the Young's modulus, ultimate tensile strength, and tensile toughness for 4, 10, and 6 folds, respectively. New sandwich-tubular of structure. Mechanics enhancement via structure engineering. Atomistic insights including vibration density state analysis. Outstanding properties promising for applications in interconnects. Abstract: The miniaturization of microchips requires high strength and conductivity of nanoscale interconnects. With utmost mechanical strength, carbon nanotubes (CNTs) are a common reinforcement. An open issue is how to improve the mechanical strength of CNT-metal composites in nanoscale. Here, via structure engineering, we introduce a novel CNT-sandwiched tubular copper nanocomposite. Theoretical enhancement factor referring to 5-nm-wire copper is approximately 4, 10, and 6 folds for Young's modulus, ultimate tensile strength, and tensile toughness, respectively, using single-walled CNT reinforcers. The enhancement can be further increased with the number of walls of CNT, as well as the reduction of the cross-section size. The reinforcement is proportional to CNT volume fraction, which is higher than that of conventional Halpin-Tsai model, up to 2 times. Even at the high temperature of 900 K, the nanocomposite structure still has a considerably high Young's modulus (219.8 GPa), ultimate tensile strength (26.0 GPa) and tensile toughness (2.22 GJ m −3 ), suggesting advanced high-temperature applications. Vibration density of state analysis reveals the origin of the enhancement and the change of CC bonds state during tensile process. The abnormally high reinforcement suggests the essential role of nanostructure engineering.