• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1917-1921
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• 2008

Ultraviolet-nanoimprint lithography (UV-NIL) is promising technology for cost effectively defining micro/nano scale structure at room temperature and low pressure. In addition, this technology is fascinating because of it's possibility for high-throughput patterning without complex processes. However, to acquire good micro/nano patterns using this technology, there are some challenges such as uniformity and fidelity of patterns, etc. In this paper, we have focused on uniform contact mechanism and performed contact mechanics analysis. The dimension of the flexible sheet to get adequate uniform contact area has been obtained from contact mechanics simulation. Based on this analysis, we have made a uniform pressurizing device and confirmed its uniform pressurized zone using a pressure sensing paper.

• Journal of the Korean institute of surface engineering
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• v.43 no.4
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• pp.170-175
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• 2010

The GaAs epitaxial layers were grown on Si(100) substrates by molecular beam epitaxy(MBE) using the two-step method. The Si(100) substrates were cleaned with different surface cleaning method of vacuum heating, As-beam, and Ga-beam at the substrate temperature of $800^{\circ}C$. Growth temperature and thickness of the GaAs epitaxial layer were $800^{\circ}C$ and 1 ${\mu}m$, respectively. The surface structure and epitaxial growth were observed by reflection high-energy electron diffraction(RHEED) and scanning electron microscope(SEM). Just surface structure of the Si(100) substrate cleaned by Ga-beam at $800^{\circ}C$ shows double domain ($2{\times}1$). RHEED patterns of the GaAs epitaxial layers grown on Si(100) substrates with cleaning method of vacuum heating, As-beam, and Ga-beam show spot-like, ($2{\times}4$) with spot, and clear ($2{\times}4$). From SEM, it is found that the GaAs epitaxial layers grown on Si(100) substrates with Ga-beam cleaning has a high quality.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.12
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• pp.1002-1009
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• 2011

The light extraction efficiency of top-emitting organic light-emitting diode (OLED) was improved by insertion of corrugation patterns between indium tin oxide and organic layers. The corrugation patterns was fabricated by nanosphere lithography, which could form a self-assembled particle monolayer over a large area. The electrical and optical properties for the OLED devices fabricated by vacuum evaporation, were investigated. We have demonstrated the enhancement of the power efficiency of corrugated OLED. As a result, the power efficiency of the corrugated OLED was found to be more than 42%.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.419-420
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• 2009

The authors fabricated the nanostructural patterns on the surface of SiN antireflection layer of polycrystalline Si solar cell and the surface of crystalline Si wafer using anodic aluminum oxide (AAO) masks in an inductively coupled plasma(ICP) etching process. The AAO nanopattern mask has the hole size of about 70~80nm and an ave rage lattice constant of 100nm. The transferred nano-patterns were observed by the scanning electron microscope (SEM) and the enhancement of solar cell efficiency will be presented.

• International Journal of Precision Engineering and Manufacturing
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• v.4 no.5
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• pp.22-26
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• 2003

In this work, a new non-photolithographic micro-fabrication technique is presented. The motivation of this work is to overcome the demerits of the most commonly used photolithographic techniques. The micro-fabrication technique presented in this work is a two-step process which consists of mechanical scribing followed by chemical etching. This method has many advantages over other micro-fabrication techniques since it is simple, cost-effective, rapid, and flexible. Also, the technique can be used to obtain a metal structure which has sub-micrometer width patterns. In this paper, the concept of this method and its application to microsystem technology are described.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.11
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• pp.228-233
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• 2002

In this work, a new non-photolithographic micro-fabrication technique is presented. The motivation of this work is to overcome the demerits of the most commonly used photolithographic techniques. The micro-fabrication technique presented in this work is a two-step process which consists of mechanical scribing followed by chemical etching. This method has many advantages over other micro-fabrication techniques since it is simple, cost-effective, rapid, and flexible. Also, the technique can be used to obtain a metal structure which has sub-micrometer width patterns. In this paper, the concept of this method and its application to microsystem technology are described.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.12 s.189
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• pp.128-134
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• 2006

Two-dimensional nano-patterns are fabricated using immersion holographic lithography. The photoresist layer is exposed to an interference pattern generated by two incident laser beams($\lambda$=441.6 nm, He-Cd laser) of which the pitch size is less than 200 nm. Good surface profiles of the 2 dimensional patterns are achieved by trimming the lithography process parameters, such as, exposure time, developing time and refractive index of medium liquid.

• Journal of the Optical Society of Korea
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• v.20 no.2
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• pp.245-250
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• 2016

In this paper, we demonstrate a self-imaging technique that can visualize longitudinal interference patterns behind periodically-structured objects, which is often referred to as Talbot carpet. Talbot carpet is of great interest due to ever-decreasing scale of interference features. We demonstrate experimentally that Talbot carpets can be imaged in a single exposure configuration revealing a broad spectrum of multi-scale features. We have performed rigorous diffraction simulations for showing that Talbot carpet print can produce ever-decreasing structures down to limits set by mask feature sizes. This demonstrates that large-scale pattern masks may be used for direct printing of features with substantially smaller scales. This approach is also useful for characterization of image sensors and recording media.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.940-944
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• 2003

With the increasing demand for plastic micro components, micro-/nano-molding using the mother stamper has received much attention. If the replication temperature is too high, the adhesion between the stamper and the polymer melt may deteriorate the surface quality of the replicated part, excessively wearing down the stamper. In this paper, an experimental method analyzes the temperature dependency of the anti-adhesion property between the actual stamper with patterns of sub-micrometer and the polymer melt. As a practical example, a correlation between the contact angle of the stamper and the surface quality of the molded substrates as a function of the replication temperature, respectively, was obtained quantitatively.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1963-1966
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• 2008

We fabricate and evaluate the metal-oxide-semiconductor (MOS) transistor probe with the focused-ionbeam (FIB) for surface electric properties. The probes are designed with the rectangular and V-shaped structures, and their dimensions are determined considering the contact mode operation. The conductive nano tip is grown with FIB system, and deposition condition is controlled for the sharp tip. The fabricated device is applied to the various test patterns like the metal lines and PZT poling regions, and the results show the well defined measurement patterns.