Fabrication and Characterization of Copper Nanowires: An Overview

Abstract

Copper (Cu) is one of the most important metals in modern electronic technology. Keeping in view its role in nanoelectronics, we have fabricated copper nanowires of diameters 100 and 200 nm using Anodic Alumina and polymer membranes as templates. Template-based growth of copper nanowires has been realized using conventional electro deposition technique in an electrochemical cell designed in our laboratory. Fabrication of copper nanowires is one of the most important thrust areas of nanotechnology because of their potential use in the micro/nanoelectronics industry and, in particular, for interconnection in electronic circuits. Many methods have been developed for the fabrication of copper nanowires but template synthesis is considered to be the most suitable and useful for growth of nanowires. Electrochemical deposition route is easy, low-cost as well as less cumbersome compared to other fabrication techniques, namely, pulsed laser deposition (PLD), vapour-liquid-solid (VLS) method and chemical vapour deposition (CVD).Scanning Electron Microscope (SEM) is used to calculate the aspect ratio of nanowires. Field Emission Scanning Electron Microscope (FESEM) images and Energy Dispersive X-ray Analysis (EDX) reveal morphology and chemical composition of fabricated nanowires. The morphology of nanowires shows some interesting features. X-ray diffraction (XRD) spectrum reveals crystalline nature of Cu nanowires with crystallite size of 1.12 nm. During our experiments, we observed that when we failed to fabricate nanowires in polymer templates, what we got was some exotic patterns of metallic copper in the shape of copper buds and flowers on the cathode surface. There is as yet no specific theory to explain exotic patterns developed during electrodeposition of copper in anodic alumina or polymer templates. It is speculated that overdeposition of copper results in formation of exotic patterns.

Keywords: Electrodeposition, Anodic alumina   membrane, Cu nanowires, nanoflowers and nanobuds, Polycrystalline Cu crystals, XRD.