Spatial modulation of nanopattern dimensions by combining interference lithography and grayscale-patterned secondary exposure

Abstract

Functional nanostructures are exploited for a variety of cutting-edge fields including plasmonics, metasurfaces, and biosensors, just to name a few. Some applications require nanostructures with uniform feature sizes while others rely on spatially varying morphologies. However, fine manipulation of the feature size over a large area remains a substantial challenge because mainstream approaches to precise nanopatterning are based on low-throughput pixel-by-pixel processing, such as those utilizing focused beams of photons, electrons, or ions. In this work, we provide a solution toward wafer-scale, arbitrary modulation of feature size distribution by introducing a lithographic portfolio combining interference lithography (IL) and grayscale-patterned secondary exposure (SE). Employed after the high-throughput IL, a SE with patterned intensity distribution spatially modulates the dimensions of photoresist nanostructures. Based on this approach, we successfully fabricated 4-inch wafer-scale nanogratings with uniform linewidths of <5% variation, using grayscale-patterned SE to compensate for the linewidth difference caused by the Gaussian distribution of the laser beams in the IL. Besides, we also demonstrated a wafer-scale structural color painting by spatially modulating the filling ratio to achieve gradient grayscale color using SE.

Design of a high-resolution magneto-plasmonic biosensor for analyte detection

“…Fabrication of sub-10 nm structures is possible using high resolution techniques such as electron beam lithography [25], and focused ion beam [26]. Unlike finesse in engraving, these methods are not efficient due to the type of serialization [27]. A more suitable fabrication method is laser-assisted lithography, which includes nanoimprint lithography [28] and laser interference lithography (LIL) [29].…”

Flexible Manipulated Interference Lithography Incorporating Modulated Optical Fourier Transform System

“…For instance, by proper selection of the interference intensity distribution or grayscale-patterned secondary exposure, the metastructures with different feature shapes can be obtained. [27,28] By varying the intersectional angle with steering beams through gimbal/reflective mirrors, metasurfaces with tunable periodicities can be produced. [29][30][31][32][33][34] By adjusting the distance between the cylindrical lens and the grating sample as well as by changing the exposure angle between the two beams, varied-line-spacing switchable meta-grating is achieved.…”

Ultralong, High Aspect Ratio Graphene Nanoribbon Arrays Fabricated by Laser Interference Lithography: Implications for Integrated Nanocircuits

“…Typically, lithography with light interference can get large scale fabrication of periodic nanostructures. 22 Meanwhile, designed structures like nanodots and nanostrips arrays can also be achieved on sample surfaces by multiple laser sources interaction. 23,24 It should be noted that strong surface electromagnetic fields can be generated at the near field under ultrafast laser irradiation, 25,26 which can be further manipulated in structures with designed dielectric environments.…”

“…Recently, optical methods (e.g., ultrafast laser lithography) have been widely used for precise structure fabrication in the micro/nanoscale range. − In order to achieve mass production of nanostructures, special optical modulation (e.g., spatial or temporal) of laser beams is normally needed. Typically, lithography with light interference can get large scale fabrication of periodic nanostructures . Meanwhile, designed structures like nanodots and nanostrips arrays can also be achieved on sample surfaces by multiple laser sources interaction. , It should be noted that strong surface electromagnetic fields can be generated at the near field under ultrafast laser irradiation, , which can be further manipulated in structures with designed dielectric environments.…”