Large area patterning using interference and nanoimprint lithography

Abstract

Interference lithography (IL) is the best suited technology for the origination of large area master structures with high resolution. In prior works, we seamlessly pattern areas of up to 1.2 x 1.2 m2 with periodic features, i.e. a diffraction grating with a period in the micron range. For this process we use an argon ion laser emitting at 363.8 nm. Thus, feasible periods are in the range of 100 μm to 200 nm. Edge-defined techniques or also called (self-aligned) double patterning processes can be used to double the spatial frequency of such structures. This way, we aim to reduce achievable periods further down to 100 nm. In order to replicate master structures, we make use of nanoimprint lithography (NIL) processes. In this work, we present results using IL as mastering and NIL as replication technology in the fields of photovoltaics as well as display and lighting applications. In photovoltaics different concepts like the micron-scale patterning of the front side as well as the realization of rear side diffraction gratings are presented. The benefit for each is shown on final device level. In the context of display and lighting applications, we realized various structures ranging from designed, symmetric or asymmetric, diffusers, antireflective and/or antiglare structures, polarization optical elements (wire grid polarizers), light guidance and light outcoupling structures

Stencil Lithography for Scalable Micro- and Nanomanufacturing

“…The patterning coverage area can also be expanded by longer expansion of the beams with a higher laser power. Recently, Bläsi et al [ 87 ] demonstrated the fabrication of nanostructures of 200 nm in periodicity uniformly over a surface area of 1.2 m × 1.2 m. After the creation of the nanopatterns, a mixture solution of hydrogen peroxide and ammonia were used to release the membrane from the silicon substrate via bubbling [ 88 ]. This results in the floatation of the membrane on the solution-free surface ( Figure 9 a).…”

Large-Area Nanoimprint Lithography and Applications

“…Moreover, it has become a perfect match for some emerging application fields that are in great need of largearea patterning of submicro and nanoscale features at a low cost, such as patterned magnetic media, high-brightness light-emitting diodes (HB-LEDs), anti-reflective coatings or films, flexible electronics, printed electronics, OLED, wire grid polarizer, flat panel display, microfluidic devices, etc. In particular, this technique has demonstrated great commercial prospects in several market segments, HB-LEDs, anti-reflective coatings or films with moth-eye structures, flexible electronics, solar cells, architectural glass, WGP, optical elements, patterned media, micro-lens arrays, and functional polymer devices [1][2][3][4][5][38][39][40][41]. Large-Area Nanoimprint Lithography and Applications http://dx.doi.org/10.5772/intechopen.72860…”

“…Large-area nanopatterning has demonstrated great potential which can significantly enhance the performance of many devices and create innovative products, such as LEDs, solar cells, hard disk drives, laser diodes, displays, sub-wavelength optical elements, antireflective glass with moth's eye structures, flexible electronics, OLED, etc. [1][2][3][4][5][6][7]. For example, the solar cells with submicro anti-reflective coating exhibited higher photocurrent and higher power conversion efficiency compared to those without nanostructures [8].…”

Methylated Silica Surfaces Having Tapered Nipple-Dimple Nanopillar Morphologies as Robust Broad-Angle and Broadband Antireflection Coatings

“…Ideal moldable materials gathering all the required properties can be found in organic polymers. They can be processed with high throughput soft-nano imprint lithography (NIL) methods 19,20,21 ,…”