Optical proximity correction (OPC) in near-field lithography with pixel-based field sectioning time modulation

Abstract

Subwavelength features have been successfully demonstrated in near-field lithography. In this study, the point spread function (PSF) of a near-field beam spot from a plasmonic ridge nanoaperture is discussed with regard to the complex decaying characteristic of a non-propagating wave and the asymmetry of the field distribution for pattern design. We relaxed the shape complexity of the field distribution with pixel-based optical proximity correction (OPC) for simplifying the pattern image distortion. To enhance the pattern fidelity for a variety of arbitrary patterns, field-sectioning structures are formulated via convolutions with a time-modulation function and a transient PSF along the near-field dominant direction. The sharpness of corners and edges, and line shortening can be improved by modifying the original target pattern shape using the proposed approach by considering both the pattern geometry and directionality of the field decay for OPC in near-field lithography.

Plasmonic Lithography: Recent Progress

“…Progress in the past few years of plasmonic lithography has reached a bottleneck, with transfer of many of the methods into production or manufacturing being hindered by limitations such as the extreme sensitivity of plasmonic effects to nanoscale surface roughness or the requirements for near‐field mask‐resist contact. Many researchers focus their attention on characterizing and perfecting existing superlens lithography processes regarding silver surface roughness and proximity correction due to object–image distance . Claims about potentials to fabricate nanostructures on the order of sub‐10 nm had been made for reducing exposure wavelength from blue—near UV (g/h/i line at 442/405/365 nm) to industrial mainstream 193 nm deep UV light.…”

“…By calibrating the ridge gap size, the theoretical resolution of bowtie aperture lithography can be reduced to 7 nm . An optical proximity correction method by modulating dosage control of the exposure reported most recently has demonstrated significantly improved image quality ( Figure ) . Applications of direct‐write plasmonic lithography for making nanoimprint masters has been demonstrated, showing that this is a viable alternative to vacuum‐based changed‐particle (e‐beam or ion‐beam) lithography techniques …”

“…Lithographic results after proximity correction exhibited distinct improvement in the resolution, especially around corners and edges. Reproduced with permission . Copyright 2018, IOP Publishing.…”

Quantitative analysis and modeling of line edge roughness in near-field lithography: toward high pattern quality in nanofabrication

“…Near-field lithography (NFL) is a sub-diffraction-limited nanopatterning technology by exploiting surface plasmon polaritons (SPPs) and the diffracted field such as quasi-spherical waves (QSWs) [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. These waves are excited by an incident light and confined in the horizontal plane and the perpendicular direction through strong near-field coupling via evanescent photons.…”

“…The advances in nanoscale feature-size controllability and scalability allow NFL to be used for 1-to 2.5-dimensional surface nanofabrication [2,3,6,15]. Furthermore, optical proximity correction methods have also been proposed to achieve high pattern fidelity control by adjusting the proximity effects caused by evanescent waves [16][17][18]. However, the previously reported experimental results suffer from a critical issue in terms of line edge roughness (LER) even over a small patterning area, which can limit the applications of NFL [2,3,6,16,19,20].…”