Fabrication of Orderly Copper Particle Arrays on a Multi-Electrolyte-Step Anodic Aluminum Oxide Template

Chun-Ko Chen,Cheng-Chung Lee,Sheng-Hui Chen,Der-Sheng Chan

doi:10.1155/2013/784927

Chun-Ko Chen, Cheng-Chung Lee + Show 2 more

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https://doi.org/10.1155/2013/784927

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Abstract

A multi-electrolyte-step (MES) anodic aluminum oxide (AAO) method was used to achieve nanochannel arrays with good circularity and periodic structure. The nano-channel array fabrication process included immersion in a phosphoric acid solution with a 120–150 bias voltage. Bowl-shaped structures were then formed by removing the walls of the nano-channel arrays. The nano-channel arrays were grown from the bottom of the bowl structure in an oxalic solution using a 50 V bias voltage. A comparison of this new MES process with the one-step and five-step AAO process showed a 50% improvement in the circularity over the one-step process. The standard deviation of the average period in the MES array was 25 nm which is less than that of one-step process. This MES method also took 1/4 of the growing time of the five-step process. The orderliness of the nano-channel arrays for the five-step and MES process was similar. Finally, Cu nanoparticle arrays with a 200 nm period were grown using an electroplating process inside the MES nano-channel arrays on fluorine doped tin oxide glass. Stronger surface plasmon resonance absorption from 550 nm to 750 nm was achieved with the MES process than was possible with the one-step process.

Highlights

In recent years, surface plasmon resonance (SPR) in nanoparticle array has attracted a lot of attention because of the adjustable absorption band [1, 2]
Analysis of the scanning electron microscope (SEM) images of nanochannel arrays grown through the traditional onestep and five-step processes and the MES anodic aluminum oxide (AAO) process was carried out
It was found that the circularity in the nanochannel arrays grown using the one-step AAO process (120–140 V) was less than 50% of that obtained with the five-step or MES methods

Summary

Introduction

Surface plasmon resonance (SPR) in nanoparticle array has attracted a lot of attention because of the adjustable absorption band [1, 2]. There have been some methods for growing good quality AAO nanochannel arrays developed. They require either an increase in circularity or improvement in the period of the channels, so it becomes a long process [6]. The problem is the thickness of the raw material, Al, has to be greater than 1 μm, which is too thick for the deposition of a good quality of film Another method involves using mixed electrolytes to improve the circularity of the nanochannel arrays. The limitations of this method are that the period of the arrays that can be grown is less than 150 nm and the arrangement of the arrays is irregular [8, 9]. A nanochannel template was applied for the masking of antireflectance structures on a large area [12]

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