Self-Aligned Plasmonic Lithography for Maskless Fabrication of Large-Area Long-Range Ordered 2D Nanostructures

Abstract

This paper proposes a one-step maskless 2D nanopatterning approach named self-aligned plasmonic lithography (SPL) by line-shaped ultrafast laser ablation under atmospheric conditions for the first time. Through a theoretical calculation of electric field and experimental verification, we proved that homogeneous interference of laser-excited surface plasmon polaritons (SPPs) can be achieved and used to generate long-range ordered 2D nanostructures in a self-aligned way over a wafer-sized area within several minutes. Moreover, the self-aligned nanostructures can be freely transferred between embossed nanopillars and engraved nanoholes by modulating the excitation intensity of SPPs interference through altering the incident laser energy. The SPL technique exhibits further controllability in the shape, orientation, and period of achievable nanopatterns on a wide range of semiconductors and metals by tuning processing parameters. Nanopatterned films can further act as masks to transfer structures into other bulk materials, as demonstrated in silica.

Line‐Shaped Laser Lithography for Efficiently Fabricating Flexible Transparent Electrodes with Hierarchical Metal Grids across λ/10 to Microscale

“…Then the line‐shaped laser pulses are spatially separated for discrete ablation by tuning the relationship between laser repetition frequency and scanning speed. [ 29 ] For film materials, their ablation thresholds will significantly decrease with the reduction of the film thickness. [ 30 ] This makes it easy to find laser fluence low enough to completely remove the metal film without obvious damage to the substrate.…”

Laser Constructing Short‐Range Disordered Metagratings for Visible Near‐Infrared Polarization‐Independent Absorption

“…Notably, the periodic energy deposition can be stably achieved on GST upon various substrates, including metal, semiconductor, and dielectric materials (Figure 2b,d and Figure S3, Supporting Information), as the phase-matching condition can be satisfied from the grating coupling effect. [18][19][20] During laser-induced periodic ablation, the laser-induced thermal effect can further cause the LIPSS melt and reorganization including dewetting and crystallization and finally results in the short-range disordered formation of LIPSS (Figure 2a2,a3). The Rayleigh-Plateau hydrodynamic instability contributes to the wavy-like morphology of LIPSS during the thermal reorganization, as observed in Figure 2b.…”

“…[21] Meanwhile, the GST, as a kind of phase-changing material, can locally crystallize from an amorphous state under laser irradiation. [18,32] The local crystallization can also lead to the disordered formation of LIPSS with fluctuant morphology, which can be clearly observed on the LIPSS consisting of many crystallized nanograins after etching in Tetramethylammonium hydroxide (TMAH) solution (Figure 2a4,c). To verify the complete crystallization of GST LIPSS, we conducted Raman tests an amorphous GST film, a crystalline GST film, and three randomly selected regions on the GST LIPSS area (named GST LIPSS 1, 2, 3).…”

“…Generally, multi-layers or complicated structures with an elaborated design are usually required to meet the wide bandwidth absorption demands, whose low-cost and high-efficient fabrication methods are still a long-pending challenge to overcome.A well-known light-driven self-organization phenomenon called laser-induced periodic surface structures (LIPSS) has attracted growing attention due to the advance of mask-free large-area surface patterning ability of subwavelength structures with long-range order. [18][19][20][21] These merits endow this laser nanopatterning technique to be potent for scalable, low-cost, and fast manufacturing of metasurfaces. [22][23][24][25][26] Nevertheless, most LIPSS are usually nanogratings that exhibit an obvious anisotropic property.…”

Optimization mechanism and applications of ultrafast laser machining towards highly designable 3D micro/nano structuring

“…4 Additionally, there is no development and rinsing in ultrafast laser processing; therefore, it has the advantages of few steps, no mask, fast processing and environmental friendliness. [5][6][7] These merits lead to many applications in a variety of aspects, such as the use of ultrafast laser-induced microexplosion to create and recover high-density polymorphs, 8 ultrafast laser pulse for building photonic lattices, 9 and direct nanowriting in air. 10 Also, these characteristics enable ultrafast laser to achieve ultrahigh precision in the processing of three-dimensional (3D) micro/nano structures.…”