Printing sub-micron structures using Talbot mask-aligner lithography with a 193 nm CW laser light source

Abstract

A continuous improvement of resolution in mask-aligner lithography is sought after to meet the requirements of an ever decreasing minimum feature size in back-end processes. For periodic structures, utilizing the Talbot effect for lithography has emerged as a viable path. Here, by combining the Talbot effect with a continuous wave laser source emitting at 193 nm, we demonstrate successfully the fabrication of periodic arrays in silicon substrates with sub-micron feature sizes. The excellent coherence and the superior brilliance of this light source, compared to more traditional mercury lamps and excimer lasers as light source, enables the efficient beam shaping and a reduced minimum feature size at a fixed gap of 20 µm. We present a comprehensive study of proximity printing with this system, including simulations and selected experimental results of prints in up to the fourth Talbot plane. This printing technology can be used to manufacture optical metasurfaces, bio-sensor arrays, membranes, or microchannel plates.

Fabrication of metal three-dimensional periodic nanostructures by diffraction phenomenon

“…On the other hand, there have been several studies on the photo lithography using diffraction phenomenon, which is one of the large area processing methods for 3D periodic nanostructures of resins [11,12] . This processing method utilizes the periodic light intensity distribution generated by plane wave transmission via a grating mask [12,13] . However, it is difficult to fabricate metal 3D periodic nanostructures because the processing method is confined for the photosensitive resin as the material to be processed.…”

Fabrication of three-dimensional high-aspect-ratio structures by oblique-incidence Talbot lithography

“…One alternative, known as the Talbot lithography process, makes use of grating masks to generate multiple-wave interference and is considered well-suited to the fabrication of 3D structures [24]. In this process, which was reported for the first time by Jeon et al in 2004 [24,25], 3D periodic nanostructures can be fabricated over a large area at one time by a process known as "printing periodic light intensity distribution", which is generated by plane wave transmission via a grating mask [26,27]. However, this Talbot method is disadvantageous in terms of fabrication flexibility because the aspect ratios of fabricated structures are limited by the Talbot effect period.…”

Spin-wave Talbot effect in thin ferromagnetic film

“…In recent years, this effect has been extensively revisited, e.g., see 18 and references therein. It has been used to improve x-ray imaging 19 and advance the process of lithographic patterning [20][21][22] , and proposed for realization of some physical models and computing scenarios [23][24][25] , the applications of which can be interesting also for magnonics. Apart from electromagnetic waves propagating in a medium, the Talbot effect has already been demonstrated for plasmons 26 , waves in fluids 27,28 , and exciton-polaritons 29 , but for SWs it has not been shown so far.…”