• International Journal of Precision Engineering and Manufacturing
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• v.6 no.4
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• pp.49-54
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• 2005

In this paper, micro structuring technique using localized electrochemical deposition (LECD) with ultra short pulses was investigated. Electric field in electrochemical cell was localized near the tool tip end region by applying pulses of a few hundreds of nano second duration, Pt-Ir tip was used as a counter electrode and copper was deposited on the copper substrate in mixed electrolyte of 0.5 M $CuSO_4$ and 0.5 M $H_2SO_4$, The effectiveness of this technique was verified by comparison with ECD using DC voltage. The deposition characteristics such as size, shape, surface, and structural density according to applied voltage and pulse duration were investigated. The proper condition was selected based on the results of the various experiments. Micro columns less than $10{\mu}m$ in diameter were fabricated using this technique. The real 3D micro structures such as micro spring and micro pattern were made by the presented method.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.745-748
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• 1995

Magnetic nanoparticles of iron and iron oxide have been prepared in a modified upward thermal diffusion cloud chamber using pulsed laser evaporation. SEM/TEM studies of these particles reveal a size distribution with a mean diameter of about $60\;{\AA}$. FTIR spectrum measurements are used to investigate the difference in oxidation level between nanoparticles prepared at different partial oxygen pressures. The complex magnetic behaviour of these particles was studied using DC- and AC-susceptibility measurements. All samples exhibit superparamagnetism with blocking temperatures ranging from 50 K to above room temperature. The coercivity fields as well as the dependence of the blocking temperature on measuring frequency have been studied. magnetic anisotropy constants are found to be one order of magnitude higher than is known for the bulk values. The mean particle size estimated from the magnetic data is found to be in perfect agreement with the TEM observations.

• Journal of the Semiconductor & Display Technology
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• v.16 no.2
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• pp.89-93
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• 2017

For various process pressures, aluminum doped zinc oxide(AZO) films were deposited by in-line pulsed-DC sputtering. The deposited AZO films were optically and electrically investigated and analyzed for the window layers of CIGS solar cell systems. As the pressure was increased from 9 mtorr to 15 mtorr, the thickness of AZO was decreased as a result of scattering and its sheet resistance was rapidly increased. The transmittance of AZO was slightly decreased as the pressure was increased and the calculation of figure of merit(F.O.M) was dependent on the sheet resistance. The structural characteristics of AZO thin films analyzed by X-ray diffraction(XRD) showed no significant dependency according to the pressure.

• Journal of the Semiconductor & Display Technology
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• v.16 no.4
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• pp.16-19
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• 2017

For the economical and environmental-friendly fabrication of polisher, Mo mask layer were sputtered on glass substrate instead of Cr mask material. Mo mask layers were sputtered by pulsed-DC sputtering and Photoresist patterns were formed on Mo mask layer for different develop times and optimized. After Mo mask layer were patterned and exposed glass was wet etched by HF solution for different etching times, the remaining Mo mask was stripped by using Al etchant. Develop time of 30 sec and HF wet etching time of 3 min were selected as optimized process condition and applied to the fabrication of polisher.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.137.2-137.2
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• 2003

Dendritic cells (DCs) are known to professional antigen presenting cell (APC). Due to the role as an effective activator of cytotoxic T Lymphocytes by expressing MHC, adhesion and co-stimulatory molecules, DCs are now widely recognized to play an important role in the immune responses to tumors.We investigated the effect of cultured DCs in murine melanoma pulmonary metastasis model. To follow the metastasis protocol, syngenic melanoma cells were inoculated intra-venously into the mouse (B16F10 into the C57BL/6)8 days prior to the first DC injection (1$\times$106 DCs/ mouse, i.p.) and the autologous tumor cell lysate pulsed-DCs were injected as a therapeutic module twice in two weeks. (omitted)

• Journal of the Korean institute of surface engineering
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• v.53 no.6
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• pp.306-311
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• 2020

In this work, diamond-like carbon (DLC) films are coated onto plasma nitrided AISI 4140 steel by DC-pulsed PECVD. One problem of DLC films is their very poor adhesion on steel substrates. The purpose of the nitriding was to enhance adhesion between the substrate and the DLC films. The white layer formation is avoided. Plasma nitriding increased adhesion from 8 N for DLC coating to 25 N for duplex coating. Duplex plasma nitriding/DLC coating was proven to be more effective in improving the adhesion. The purpose of the bond layer was to enhance adhesion between the substrate and the DLC films.

• Journal of the Korean institute of surface engineering
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• v.39 no.5
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• pp.206-209
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• 2006

Indium tin oxide (ITO) films were synthesized on polymer (PES, polyethersulfone) at room temperature by pulsed DC magnetron sputtering. By the control of introducing hydrogen to argon atmosphere, the resistivity of ITO films was obtained at $5.27\;{\times}\;10^{-4}\;{\Omega}{\cdot}cm$ without substrate heating in comparison with $2.65\;{\times}\;10{-3}\;{\Omega}{\cdot}cm$ under hydrogen free condition. ITO film synthesized at Ar condition was changed from amorphous to crystalline. These result from the enhancement of electron temperature in $Ar\;+\;H_2$ plasma, which induces the increase of ionization of target materials and argon. The dominant increase of ions such as In II and O II and neutral Sn I was monitored by optical emission spectroscopy (OES). Thermal energy required for the crystalline film formation is compensated by kinetic energy transfer through ion bombardments to substrate.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.10
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• pp.2359-2368
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• 2013

In this paper, an IRD (internal read data) circuit preventing the reentry into the read mode while keeping the read-out DOUT datum at power-up even if noise such as glitches occurs at signal ports such as an input signal port RD (read) when a power IC is on, is proposed. Also, a pulsed WL (word line) driving method is used to prevent a DC current of several tens of micro amperes from flowing into the read transistor of a differential paired eFuse OTP cell. Thus, reliability is secured by preventing non-blown eFuse links from being blown by the EM (electro-migration). Furthermore, a compared output between a programmed datum and a read-out datum is outputted to the PFb (pass fail bar) pin while performing a sensing margin test with a variable pull-up load in consideration of resistance variation of a programmed eFuse in the program-verify-read mode. The layout size of the 8-bit eFuse OTP IP with a $0.18{\mu}m$ process is $189.625{\mu}m{\times}138.850{\mu}m(=0.0263mm^2)$.

• Korean Journal of Materials Research
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• v.8 no.3
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• pp.263-267
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• 1998

In this study, we have fabricated in-situ multilayer $YBa_2Cu_3O_{7-\delta}$/$SrTiO_{3}$/$YBa_2Cu_3O_{7-\delta}$ ramp edge type junctions by using a metal mask and pulsed laser deposition method and studied the junction properties. The junctions showed RSJ-like I-V characteristics. The normal state junction resistance R, of $18 \omega$ was nearly constant with temperature. The dc-SQUID sensors fabricated with the junctions show a sensitivity that transfer function dV/$d\Phi$)~$22\mu$V/$\Phi_{0}$, indicating that the in-situ ramp edge type junction is potentially useful for sensor application.

• Archives of Pharmacal Research
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• v.22 no.4
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• pp.340-347
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• 1999

Dendritic cells (DCs) are potent professional antigen-presenting cells (APC) capable of inducing the primary T cell response to antigen. Although tumor cells express target antigens, they are incapable of stimulating a tumor-specific immune response due to a defect in the costimulatory signal that is required for optimal activation of T cells. In this work, we describe a new approach using tumor-DC coculture to improve the antigen presenting capacity of tumor cells which does not require a source of tumor-associated antigen. Immunization of a weakly immunogenic and progressive tumor cocultured with none marrow-derived DCs generated an effective tumor vaccine. Immunization with the cocutured DCs was able to induce complete protectiv immunity against tumor challenges and was effective for the induction of tumor-specific CTL (cytotoxic T lymphocyte) activity. Furthermore, high NK cell activity was observed in mice in which tumors were rejected. In addition, immunization with tumor-pulsed DC s induced delayed tumor growth, but not tumor eradication in tumor-bearing mice. Our results demonstrate that coculture of DCs with tumors generated antitumor immunity due to the NK cell activation as well as tumor-specific T cell. This approach would be used for designing tumor vaccines using DCs when the information about tumor antigens is limited.