Low-cost Fresnel microlens array fabricated by a home-built maskless lithography system

The design and manufacture of cost-effective miniaturized optics at wafer level, usingadvanced semiconductor-like techniques, enables the production of reduced form-factor cameramodules for optical devices. However, suppressing the Fresnel reflection of wafer-level microlensesis a major challenge. Moth-eye nanostructures not only satisfy the antireflection requirementof microlens arrays, but also overcome the problem of coating fracture. This novel fabricationprocess, based on a precision wafer-level microlens array mold, is designed to meet the demandfor small form factors, high resolution, and cost effectiveness. In this study, three different kinds ofaluminum material, namely 6061-T6 aluminum alloy, high-purity polycrystalline aluminum, and purenanocrystalline aluminum were used to fabricate microlens array molds with uniform nanostructures.Of these three materials, the pure nanocrystalline aluminum microlens array mold exhibited auniform nanostructure and met the optical requirements. This study lays a solid foundation for theindustrial acceptation of novel and functional multiscale-structure wafer-level microlens arrays andprovides a practical method for the low-cost manufacture of large, high-quality wafer-level molds.

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Realization of Three-Dimensional Nanostructure Fabrication by Nanoimprint on Silicon Substrate

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.211-212.1105 ◽

2011 ◽

Vol 211-212 ◽

pp. 1105-1109

Author(s):

Xi Qiu Fan

Keyword(s):

Silicon Substrate ◽

Low Cost ◽

Three Dimensional ◽

Microlens Array ◽

Optical Lithography ◽

High Fidelity ◽

Fabrication Method ◽

Nanostructure Fabrication ◽

Large Area ◽

3D Nanostructures

Traditional optical lithography techniques to fabricate three-dimensional (3D) nanostructures are complicated and time consuming. Due to the capability to replicate nanostructures repeatedly in a large area with high resolution and uniformity, nanoimprint (NI) has been recognized as one of the promising approaches to fabricate 3-D nanostructures with high throughput and low cost. This paper introduces a novel 3-D nanostructure fabrication method by nanoimprint on silicon substrate. Nanoscale gratings and microlens array are taken as examples of 3-D nanostructures fabricated by nanoimprint. High fidelity demonstrates the possibility of nanoimprint to fabricate 3-D nanostructures on silicon substrate.

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Design and investigation of a maskless lithography system for printing patterns on the inside surface of a long pipe

Photomask Japan 2019: XXVI Symposium on Photomask and Next-Generation Lithography Mask Technology ◽

10.1117/12.2532442 ◽

2019 ◽

Author(s):

Toshiyuki Horiuchi ◽

Kousuke Akitani ◽

Kazumi Imahashi ◽

Yuta Suzuki ◽

Jun-ya Iwasaki ◽

...

Keyword(s):

Inside Surface ◽

Maskless Lithography ◽

Lithography System

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Design and Fabrication of Wafer-Level Microlens Array with Moth-Eye Antireflective Nanostructures

Nanomaterials ◽

10.3390/nano9050747 ◽

2019 ◽

Vol 9 (5) ◽

pp. 747 ◽

Cited By ~ 4

Author(s):

Shuping Xie ◽

Xinjun Wan ◽

Bo Yang ◽

Wei Zhang ◽

Xiaoxiao Wei ◽

...

Keyword(s):

Nanoimprint Lithography ◽

Production Efficiency ◽

Low Cost ◽

Microlens Array ◽

Wafer Level ◽

Lens Array ◽

Wafer Level Packaging ◽

High Production ◽

Aspherical Lenses ◽

Profile Accuracy

Wafer-level packaging (WLP) based camera module production has attracted widespread industrial interest because it offers high production efficiency and compact modules. However, suppressing the surface Fresnel reflection losses is challenging for wafer-level microlens arrays. Traditional dielectric antireflection (AR) coatings can cause wafer warpage and coating fractures during wafer lens coating and reflow. In this paper, we present the fabrication of a multiscale functional structure-based wafer-level lens array incorporating moth-eye nanostructures for AR effects, hundred-micrometer-level aspherical lenses for camera imaging, and a wafer-level substrate for wafer assembly. The proposed fabrication process includes manufacturing a wafer lens array metal mold using ultraprecise machining, chemically generating a nanopore array layer, and replicating the multiscale wafer lens array using ultraviolet nanoimprint lithography. A 50-mm-diameter wafer lens array is fabricated containing 437 accurate aspherical microlenses with diameters of 1.0 mm; each lens surface possesses nanostructures with an average period of ~120 nm. The microlens quality is sufficient for imaging in terms of profile accuracy and roughness. Compared to lenses without AR nanostructures, the transmittance of the fabricated multiscale lens is increased by ~3% under wavelengths of 400–750 nm. This research provides a foundation for the high-throughput and low-cost industrial application of wafer-level arrays with AR nanostructures.

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A high-speed exposure method for digital micromirror device based scanning maskless lithography system

Optik ◽

10.1016/j.ijleo.2019.04.009 ◽

2019 ◽

Vol 185 ◽

pp. 1036-1044 ◽

Cited By ~ 4

Author(s):

Chao Peng ◽

Zezhou Zhang ◽

Jianxiao Zou ◽

Wenming Chi

Keyword(s):

High Speed ◽

Maskless Lithography ◽

Digital Micromirror Device ◽

Exposure Method ◽

Lithography System

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Rapid Fabrication of Micro Optical Elements Using DMD-Based Maskless Lithography Technique

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.146-147.143 ◽

2010 ◽

Vol 146-147 ◽

pp. 143-146 ◽

Cited By ~ 1

Author(s):

Xiao Wei Guo ◽

Qi Ming Dong

Keyword(s):

Low Cost ◽

Maskless Lithography ◽

Optical Elements ◽

Rapid Fabrication ◽

Lithography Technique

A low-cost microfabrication tool based on digital mirror device(DMD) is presented in this paper. The imaging principle of the system is described and the fabrication methods for binary and nonbinary micro optical elements(MOE) are also discussed in detail. It is expected to provide an understanding of MOEs fabrication using DMD-based maskless lithography technique.

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