Assembly of metallic nanoparticle arrays on glass via nanoimprinting and thin-film dewetting.

Sun-Kyu Lee,Sori Hwang,Yong-Jun Oh,Yoon-Kee Kim

doi:10.3762/bjnano.8.106

Sun-Kyu Lee, Sori Hwang + Show 2 more

Open Access

https://doi.org/10.3762/bjnano.8.106

Copy DOI

Abstract

We propose a nanofabrication process to generate large-area arrays of noble metal nanoparticles on glass substrates via nanoimprinting and dewetting of metallic thin films. Glass templates were made via pattern transfer from a topographic Si mold to an inorganically cross-linked sol–gel (IGSG) resist on glass using a two-layer polydimethylsiloxane (PDMS) stamp followed by annealing, which turned the imprinted resist into pure silica. The transparent, topographic glass successfully templated the assembly of Au and Ag nanoparticle arrays via thin-film deposition and dewetting at elevated temperatures. The microstructural and mechanical characteristics that developed during the processes were discussed. The results are promising for low-cost mass fabrication of devices for several photonic applications.

Highlights

Highresolution lithography techniques – such as electron beam lithography (EBL) or laser interference lithography (LIL) – with a conventional multistep etching process on a silicon wafer are still required to fabricate templates with nanostructured surface topographies that determine the features of the dewetted nanoparticles [1,12,13,14,15]
The applicability of a self-assembly technique that uses dewetting largely depends on how it can be combined with appropriate template materials that have both functionality and dewettability
Thin films of noble metals were deposited on imprinted resists that were converted to sol–gel silica at 550 °C and dewetted at high temperatures (≈300–500 °C) to form nanoparticles

Summary

Introduction

Substrates with periodic topography can be used to direct or control the dewetting process to form ordered arrays of nanoparticles governed by the topographic features of the underlying surface [1,2]. Noble metals (Au and Ag) were sputter-deposited onto the imprinted resist with the periodic array of inverted pyramidal pits and annealed in a furnace at ≈300–500 °C to assemble nanoparticle arrays via solid-state dewetting of the deposited films.

Objectives

Results

Conclusion