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Lee, Joon-Sub;Park, Woo-Jae;Lee, Ji-Whan;Song, Soek-Ho;Lee, Sung-Jin;Kim, Oui-Serg
- Korean Journal of Optics and Photonics
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- v.20 no.1
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- pp.23-28
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- 2009
In this study, we propose an image stitching method for large-area holographic photo lithography. In this method, a hologram medium become a hologram mask for lithography. And the mask has information for stitched images. These images are recorded by signal images which are controlled with DMD (digital micro-mirror device), and serial hologram recording is achieved with a motorized linear stage. Using this method, fringe seams appear on the stitching area. To remove these fringe seams, double exposure holographic lithography is tried. Each stitched image is recorded and reconstructed with a different reference beam. The experiments confirm that fringe seams are removed.
https://doi.org/10.3807/HKH.2009.20.1.023 인용 PDF KSCI

Park, Sungmin;Nam, Gyungmok;Kim, Jonghun;Yoon, Sang-Hee
- Transactions of the Korean Society of Mechanical Engineers A
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- v.40 no.8
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- pp.731-736
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- 2016
Three-dimensional (3D) high-aspect-ratio (HAR) microstructures for biomedical applications (e.g., microneedle, microadhesive, etc.) are microfabricated using the hybrid ultraviolet (UV) lithography in which inclined, rotational, and reverse-side UV exposure processes are combined together. The inclined and rotational UV exposure processes are intended to fabricate tapered axisymmetric HAR microstructures; the reverse-side UV exposure process is designed to sharpen the end tip of the microstructures by suppressing the UV reflection on a bottom substrate which is inevitable in conventional UV lithography. Hybrid UV lithography involves fabricating 3D HAR microstructures with an epoxy-based negative photoresist, SU-8, using our customized UV exposure system. The effects of hybrid UV lithography parameters on the geometry of the 3D HAR microstructures (aspect ratio, radius of curvature of the end tip, etc.) are measured. The dependence of the end-tip shape on SU-8 soft-baking condition is also discussed.
https://doi.org/10.3795/KSME-A.2016.40.8.731 인용 PDF KSCI

Seo, Young-Ho;Choi, Doo-Sun;Lee, Joon-Hyoung;Je, Tae-Jin;Whang, Kyung-Hyun
- Proceedings of the KSME Conference
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- 2004.04a
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- pp.978-982
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- 2004
We present high aspect ratio 100nm-scale nickel stamper using e-beam lithography process and Cr/Qz mask for the injection molding process of nano grating patterns. Conventional photolithography blank mask (CrON/Cr/Qz) consists of quartz substrate, Cr layer of UV protection and CrON of anti-reflection layer. We have used Cr/Qz blank mask without anti-reflection layer of CrON which is non-conductive material and ebeam lithography process in order to simplify the nickel electroplating process. In nickel electroplating process, we have used Cr layer of UV protection as seed layer of nickel electroplating. Fabrication conditions of photolithography mask using e-beam lithography are optimized with respect to CrON/Cr/Qz blank mask. In this paper, we have optimized e-beam lithography process using Cr/Qz blank mask and fabricated nickel stamper using Cr seed layer. CrON/Cr/Qz blank mask and Cr/Qz blank mask require optimal e-beam dosage of $10.0{\mu}C/cm^2$ and $8.5{\mu}C/cm^2$, respectively. Finally, we have fabricated $116nm{\pm}6nm-width$ and $240nm{\pm}20nm-height$ nickel grating stamper for the injection molding pattern.
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