• Journal of the Korean Vacuum Society
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• v.18 no.2
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• pp.97-101
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• 2009

In the modem semiconductor industry, the progress that consumes the most capital and labor is cleansing process. Cleansing process is to remove impurities that can affect the operation of the device and deteriorate its function. Especially, Photoresist (PR) progress that etches the device always requires cleansing at the end of the progress. Also, HDI-PR (High-Dose Ion-implanted Photoresist) created from PR progress is difficult to remove. Thus, in modem IC cleansing, many steps of cleansing are used, including dry and wet cleansing. In this paper, we suggested to combine existing dry-cleansing and wet-cleansing, each represented by plasma cleansing and stripper solution, as Plasma Liquid-Vapor Activation (PLVA). This PLVA method enhances the effect of existing cleansing solution, and decreases the amount of solution and time required to strip. We stripped HDI-PR by activated solution and measured surface hardness and Young's modulus by Nano-indenter. Nano-indenter is the equipment that determines the hardness and the modulus of elasticity by indenting nano-sized tip with specific shape into the surface and measuring weight and z-axis displacement. We measured the change of surface hardness and Young's modulus before and after the cleansing. As a result, we found out that the surface hardness of the sample sharply decreased after the cleansing by plasma-activated PR stripper solution. It can be considered that if physical surface-cleansing process is inserted after this, more effective elimination of HDI-PR is possible.

• Journal of the Korean Vacuum Society
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• v.19 no.4
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• pp.281-286
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• 2010

Thickness effects on the structural and optical properties of ZnO thin films fabricated by spin coating method have been carried out. With increase in the thickness of the ZnO thin films, the width and density of striation shape are increased. The ZnO thin film with thickness of 450 nm has a smooth surface morphology. For the ZnO thin film with a smooth surface, orientation factor ${\alpha}_{(002)}$ is sharply increased and FWHM of (002) diffraction peak is decreased compared to the ZnO thin films with a striation shape surface. Thickness and surface morphology of the ZnO thin films hardly affect the NBE peak position. However, the DLE peak position is blue-shifted as the surface morphology is changed from striation to smooth surface. The PL intensity ratio of the NBE to DLE is increased and the FWHM of NBE peak is decreased as the thickness of the ZnO thin films is increased.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.38.3-38
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• 2001

In the planetary surface exploration , micro-rovers or nano-rovers are very attractive choices for a surface exploration system providing mobility functions and other features required in the surface probe missions at small mass and relatively small cost. This paper surveys and summarizes the requirements for Mars exploration rovers in micro or nano scale and outlines the control concepts for navigation including the obstacle/hazard avoidance and the path planning. In this context, autonomous reaction capabilities are the key elements to control design in conjunction with the remote control schemes to deal with the significant signal propagation delays. Other navigation and control aspects such as the instrument fine positioning and the flip-over of the rovers are also briefly introduced. The current technical limitations of the micro- and nano-rovers are summarized.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.5
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• pp.848-854
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• 2012

SCM420 steel cutting gear to improve the durability is quenched. When quenching, increases surface hardness, a change of the physical properties and machinability or fall. This study, using a solid carbide hobs skiving hobbing gear cutting finishing. And cutting tool solid carbide TiAlN coating hove when TiAlN coating on the surface of multi-con polishing hob conducted aero lap nano polishing for each cutting. Experimental results conducted aero lap nano coating on the surface polishing tool machinability was excellent. And aero lap nano polishing tool results were reduced 2.5 times the tool wear compared to TiAlN coated tools. Excellent results were 1.42 times longer tool life.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.60-60
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• 2014

By the pre-doping technique on graphene/copper foil, we obtained the pristine sheet resistance and optical transmittance of the chlorine doped-single layer graphene $245{\Omega}/sq$ and 97% at 550 nm wavelength, respectively. X-ray photoelectron spectroscopy revealed that an extremely high Cl coverage of 47.3% of monolayer graphene surface was achieved as the highest surface-coverage graphene doping material ever reported.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.187-187
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• 2014

In this study, we investigated mechanical properties and surface characteristics of Ti-25Ta-xHf alloys. The samples were manufactured for composition of Ti-25Ta-xHf(x=0 to 15 wt. %) alloys. Each alloy was melted twenty times in an arc-melting vacuum furnace. The microstructural phases and phase transformation of Ti-25Ta-xHf alloys were identified with the aid of an XRF, XRD and DSC. And mechanical properties were investigated using Vickers hardness, nanoindentation, and tensile test.

• Journal of Surface Science and Engineering
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• v.57 no.2
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• pp.98-104
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• 2024

In order to overcome the urban heat island effect, highly functional paint is attracting attention as a promising means by shielding heat on the structure (building) surface. When a paint was prepared containing nano-sized silica particles, the heat-insulating performance was relatively higher than that of paints with other sizes. In addition, developed paints showed enhanced properties such as chemical resistance and abrasion resistance test because of the presence of nano-sized silica included in functional paint.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.39-40
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• 2009

The patterned vertical alignment (PVA) display showed good electro-optic properties such as wide viewing angle, fast response time, high Contrast Ratio. However, the device has patterned electrode on both top and bottom electrodes which requires high accuracy of assembling of top and bottom substrates in order to exhibit a high performance. So, they have disadvantage about low yield. In order to resolve these problem, in this paper, we studied about top substrate pattern free vertical alignment device associated with surface polymer stabilization using the UV curable monomer. This method shows simple progress, low cost and good electro-optic properties such as high transmittance and fast response time.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.10a
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• pp.31.2-31.2
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• 2011

We studied a method of manufacturing an anode to restrict contraction in reducing NiO/YSZ by uniformly mixing. In order to mix Ni and YSZ, a sub-micron Ni core surface was coated at high-speed by a mixture of nano-sized YSZ and a spherical core-shell was subsequently formed. The micron-sized core-shell anode powder was then heat treated at $400{\sim}1,450^{\circ}C$ in an air atmosphere and Ni was extruded and synthesized in nano-size. Subsequently, when the nano-sized mixture of the anode was heat treated and maintained at a temperature of $1,450^{\circ}C$, the anode was manufactured, where Ni and YSZ were uniformly distributed with the nano-structure. According to the nano-sized anode powder synthesis process, Ni particles were oxidized at $400{\sim}500^{\circ}C$ and became spherical by surface tension. In the case of the spherical core Ni powder, the heat treatment temperature rose to $1,250^{\circ}C$ and then a gap between the internal and external pressures occurred due to thermal and tensile stresses. A crack subsequently appeared on the surface, and the heat treatment temperature was increased continuously to increase the pressure gap and then the core Ni extruded as a nano-sized powder, Ni and YSZ uniformly distributed. It was found that the anode of 50~200 nm with a consistent structure obtained in this study has electric conductivity that is approximately 3 times larger than that of a commercial anode.

• Korean Journal of Materials Research
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• v.19 no.4
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• pp.220-223
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• 2009

Lithium dihydrogen phosphate ($LiH_2PO_4$) powder was purchased from Aldrich Chemical Co. From the scanning electron microscope (SEM) observation, these polycrystals have dimensions in the range of $25-250{\mu}m$. The electrical conductivity was measured at a measuring frequency of 1 kHz on heating polycrystalline lithium dihydrogen phosphate ($LiH_2PO_4$) from room temperature to 493 K. Two anomalies appeared at 451 K ($T_{p1}$) and 469 K ($T_{p2}$). The electrical conductivity reached the magnitude of the superprotonic phases: $3{\times}10^{-2}{\Omega}^{-1}cm^{-1}$ at 451 K ($T_{p1}$) and $1.2{\times}10{\Omega}^{-1}cm^{-1}$ at 469 K ($T_{p2}$). It is uncertain whether the superprotonic phase transformations are due to polymorphic transitions in the bulk, surface transitions, or chemical reactions (thermal decomposition) at the surface. Considering several previous thermal studies (differential scanning calorimetry and thermogravimetry), our experimental results seem to be related to the last case: chemical reactions (thermal decomposition) at the surface with the progressive solid-state polymerization.