Effect of the Fabrication Parameters of the Nanosphere Lithography Method on the Properties of the Deposited Au-Ag Nanoparticle Arrays

Abstract

The nanosphere lithography (NSL) method can be developed to deposit the Au-Ag triangle hexagonal nanoparticle arrays for the generation of localized surface plasmon resonance. Previously, we have found that the parameters used to form the NSL masks and the physical methods required to deposit the Au-Ag thin films had large effects on the geometry properties of the nanoparticle arrays. Considering this, the different parameters used to grow the Au-Ag triangle hexagonal nanoparticle arrays were investigated. A single-layer NSL mask was formed by using self-assembly nano-scale polystyrene (PS) nanospheres with an average radius of 265 nm. At first, the concentration of the nano-scale PS nanospheres in the solution was set at 6 wt %. Two coating methods, drop-coating and spin-coating, were used to coat the nano-scale PS nanospheres as a single-layer NSL mask. From the observations of scanning electronic microscopy (SEM), we found that the matrixes of the PS nanosphere masks fabricated by using the drop-coating method were more uniform and exhibited a smaller gap than those fabricated by the spin-coating method. Next, the drop-coating method was used to form the single-layer NSL mask and the concentration of nano-scale PS nanospheres in a solution that was changed from 4 to 10 wt %, for further study. The SEM images showed that when the concentrations of PS nanospheres in the solution were 6 and 8 wt %, the matrixes of the PS nanosphere masks were more uniform than those of 4 and 10 wt %. The effects of the one-side lifting angle of substrates and the vaporization temperature for the solvent of one-layer self-assembly PS nanosphere thin films, were also investigated. Finally, the concentration of the nano-scale PS nanospheres in the solution was set at 8 wt % to form the PS nanosphere masks by the drop-coating method. Three different physical deposition methods, including thermal evaporation, radio-frequency magnetron sputtering, and e-gun deposition, were used to deposit the Au-Ag triangle hexagonal periodic nanoparticle arrays. The SEM images showed that as the single-layer PS nanosphere mask was well controlled, the thermal evaporation could deposit the Au-Ag triangle hexagonal nanoparticle arrays with a higher quality than the other two methods.

Plasmonic Aluminum Nanohole Arrays as Transparent Conducting Electrodes for Organic Ultraviolet Photodetectors with Bias-Dependent Photoresponse

“…NSL inherently produces a hexagonal NHA with the pitch determined by the nanosphere diameter and the diameter controlled by the etch conditions. A critical step in NSL is the formation of a large area, close-packed monolayer of nanospheres, and many methods for achieving this have been reported, including directional rubbing, − convective dragging, spin-coating, drop-coating, − and the air–water interface method. − …”

Nanosphere lithography: the effect of chemical etching and annealing sequence on the shape and spectrum of nano-metal arrays

“…Different metals such as gold, silver and copper are widely used in previous works [33,34,35]. Also, in some studies two or more types of metals or metal alloys are applied [36,37]. In this work, first, sputtering deposition method is used to deposit 5 nm of 𝑇 𝑖 on the template by means of Magnetron Sputtering (78540 Vernouillet-France).…”

Etchless Fabrication of High‐Quality Refractory Titanium Nitride Nanostructures

“…Another route so far used for the fabrication of plasmonic nanostructures is nanosphere lithography (NSL). [ 26–44 ] NSL may be viewed as an intermediate route of patterning because it is not based on self‐assembly, such as the bottom‐up processes, nor involves any slicing and dicing of continuous layers, as all top‐down processes. In this technique, a close packed, colloidal mask consisting of polystyrene (PS) or silica nanospheres is deposited usually by spin coating on the substrate and allows the deposition of the desired material vapors through the gaps among the nanospheres.…”

“…[ 26 ] On the contrary, the formation of well‐defined nanostructures by combining NSL with magnetron sputtering (MS) is exceptionally scarce. [ 34 ] The combination of NSL and MS usually results in a quasi‐continuous hexagonal mesh instead of isolated nanostructures [ 41–44 ] due to the lack of directionality of vapor species, which originates from the high working pressure of MS resulting in gas phase collisions; as a result, vapor is covering the entire space around the nanospheres beyond the shadow among them. [ 41–44 ] Reactive MS has not been implemented in combination with NSL so far.…”