Microstructure and Electrical Property of Copper Nanowires Fabricated by Pulsed Electrodeposition at Low Temperature

• Main Author: 林彥妙
• Other Authors: 廖建能
• Format: Others
• Language: en_US
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/28963978618249585342

碩士 === 國立清華大學 === 材料科學工程學系 === 100 === Copper (Cu) metallization possesses good electrical conductivity and has been utilized as an interconnecting material in microelectronic devices. Besides, one-dimensional (1D) Cu nanostructures have received great attention due to their different physical properties compared to traditional bulk Cu, and have shown attractive potential in nanoelectronic devices these days. However, while the dimension of devices is narrowing down to nanoscale, the material should have high mechanical strength but also remain decent electrical conductivity at the same time, in order to lower the probability of device failure by electromigration, and then extend the device lifetime. Copper with high-density nanotwins is well known to have higher mechanical strength compared to fine-grained Cu, good electrical conductivity, and moreover, better electromigration resistance. We have successfully fabricated Cu nanowires with high density of nanoscale traverse twinning structures in home-made AAO using pulsed electrodeposition. And the texture and microstructure of Cu nanowires are related to several deposition factors, such as current density and deposition temperature. X-ray diffraction (XRD) analysis on the Cu nanowires revealed a [111] preferred orientation. The average twin spacing from 10 to 30 nm have been observed by high-resolution transmission electron microscopy (TEM), and the spacing is larger when the peak current density increases. Moreover, under the same current density, the spacing becomes narrower while deposition is conducted at a lower temperature. From I-V electrical measurement, the Cu nanowires with high density of nanotwins can sustain larger density of current before failure than those without dense nanotwins.