Talbot photolithography optimization with engineered hybrid metal-dielectric mask: High-contrast and highly-uniform Talbot stripes

TL;DR

This paper introduces a hybrid amplitude-phase mask for Talbot lithography that produces highly uniform, high-contrast stripes with sub-wavelength resolution, demonstrating robustness and reproducibility through numerical simulations.

Contribution

It presents a novel hybrid mask design that enhances stripe uniformity, contrast, and resolution in Talbot lithography, surpassing traditional mask capabilities.

Findings

Achieves spatial resolution better than one-third of laser wavelength

Demonstrates robustness against mask deviations and light angle variations

Reproducible results for 1D and 2D metal-dielectric masks

Abstract

Conventional projection Talbot lithography usually employs opaque (amplitude) or transparent (phase) masks for creating a periodic array of Fresnel diffraction fringes in the photosensitive substrate. For particular mask design the longitudinal periodicity of Talbot carpet can be avoided producing quasi uniform striped pattern (Talbot stripes). We propose a novel hybrid amplitude-phase mask which is engineered for obtaining extremely smooth Talbot stripes and simultaneously high lateral optical contrast and extreme spatial resolution better than a third of laser wavelength. By means of the numerical simulations, we demonstrate the robustness of produced striped diffraction patterns against mask design deviation and light incidence angle variations. The reproducibility of the Talbot stripes is reported also for 1D and 2D metal-dielectric projection masks.