Sub-100â
nm pixel pitch via STED photolithography with a nanoprinting-at-expansion/employments-at-recovery strategy.
Opt Express
; 31(2): 2892-2901, 2023 Jan 16.
Article
in En
| MEDLINE
| ID: mdl-36785292
ABSTRACT
Featured with its extraordinary super-resolution capability, the advent of stimulated emission depletion (STED) lithography has allowed for vastly reduced minimum feature size of a single pixel down to the deep sub-diffraction scale so as to produce unprecedented nanofeatures. However, the anticipated sub-diffraction pixel pitch down below 100â
nm remains out of reach due to redundant polymerization of adjacent exposures at a short distance, so called memory effect. In this work, a nanoprinting-at-expansion/employments-at-recovery strategy is applied in the dual-beam STED lithography technique to surmount the memory effect and break adjacent-exposure limit imposed on minimizing the pixel pitch. The implementation of a femtosecond laser at a wavelength of 532â
nm, the same as the inhibition laser beam, working as the initiation laser beam, can drastically reduce the saturated inhibition laser intensity by 74% for abating redundant polymerization subjected to multiple exposures in realizing nanoscale pixel pitch. The adjacent-exposure zone can be separated by isotropically expanding an elastic PDMS substrate for further diminishing redundant polymerization. Applying stretching ratio of 30%, a minimum super-resolved nanodots pixel pitch of 96â
nm was achieved with single-dot size of 34â
nm on both planar and hierarchical substrate, which offers a record-close distance for printing adjacent pixels. With its nanometer discernibility, this method holds great promise for future versatile utilization in advanced nanoimprinting, high density data storage, etc.
Full text:
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Database:
MEDLINE
Language:
En
Year:
2023
Type:
Article