Fabrication of Size-Tunable Gold Nanoparticles Array with Nanosphere Lithography, Reactive Ion Etching, and Thermal Annealing

Abstract

Two-dimensional ordered arrays of gold (Au) nanoparticles were fabricated using two different variants of the nanosphere lithography technique. First, ordered arrays of polystyrene nanospheres on Si substrate were used as deposition masks through which gold films were deposited by electron beam evaporation. After the removal of the nanospheres, an array of triangular Au nanodisks was left on the Si substrate. After thermal annealing at increasing temperature, systematic shape transition of the nanostructures from original triangular Au nanodisks to rounded nanoparticles was observed. This approach allows us to systematically vary the size and morphology of the particles. In the second and novel technique, we made use of reactive ion etching to simultaneously reduce the dimension of the masking nanospheres and create arrays of nanopores on the substrate prior to the deposition of the Au films. These samples were subsequently annealed, which resulted in size-tunable and ordered Au nanoparticle arrays with the nanoparticles nested in the nanopores of the templated substrate. With the nanoparticles anchored in the nanopores, the substrate could be useful as a template for growth of other nanomaterials.

Colloidal Lithography

“…Using colloidal crystals as masks for catalytic etching, Zhu et al have fabricated large-scale periodic arrays of silicon nanowires and the diameters and heights of the nanowires and the center-to-center distances between the nanowires can be accurately controlled [57]. Using colloidal crystals as masks to create arrays of nanopores on supporting solid substrates via RIE, followed by consecutively deposition of gold films and removal of the colloidal masks, Ong et al have fabricated 2D ordered arrays of gold nanoparticles nested in the nanopores of the templated substrate [58]. One potential extension of having gold nanoparticles confined in nanopores is to use them as catalysts for growth of nanowires of other materials such as ZnO nanowires.…”

Window-assisted nanosphere lithography for vacuum micro-nano-electronics

“…Nanosphere lithography (NSL) [9][10][11][12] is a promising nanofabrication technology that is inexpensive, high-throughput, materials general a Author to whom correspondence should be addressed. and has been demonstrated to be well suited to fabricate nanoholes, [13][14][15] metallic nanomesh electrodes, 16,17 or silicon, [18][19][20] noble metal, 21 cobalt, 22,23 and gallium nitride nanorod arrays. 24 The function of NSL relies on templates for nanostructure patterning.…”

Large-scale Patterning of Hydrophobic Silicon Nanostructure Arrays Fabricated by Dual Lithography and Deep Reactive Ion Etching

“…The most commonly used is nanosphere lithography (NSL) [9][10][11][12][13], which has been demonstrated as an efficient way to produce nanoscale patterns over a large area with high throughput and low cost. Nanospheres can be introduced onto substrates by spin-coating [14] or created during annealing a thin metallic (Au) layer [15], or linked on wafers using self-assembling [16]. However, the shapes and the sizes of the nanoparticles created by these techniques are not as well defined as the features created by using traditional lithography, and the placing of the nanoparticles is also inexact.…”