• 한국표면공학회지
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• 제51권6호
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• pp.400-404
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• 2018

A metal 3D printer has been developed on its own to electrodeposit the localized area. Nozzles were used to selectively laminate the electrolytic plating method. To analyze the factors affecting the deposition, the stack height, thickness and surface roughness were experimentally analyzed according to the current density and the temperature of the electrolyte. Electrolytic temperature and current are electrodeposited when the deposition conditions are dominant over the etching conditions, but the thickness is kept constant. On the contrary, when the etching conditions are dominant, the electrodeposited shape is rather the etched. As a result, the uniformity of surface quality and electrodeposition rate could be improved by conducting experiments under constant conditions of electrolyte temperature and current density.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2010년도 임시총회 및 하계학술연구발표회
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• pp.70-71
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• 2010

In this study, We fabricated FePt-based perpendicular patterned media using a selective combination of E-beam lithography and either Ar plasma etching (deposition-first process) or FePt lift-off (deposition-last process). We employed the deposition-last process to avoid chemical and structural disordering by impinging Ar ions (deposition-first process). For a patterned medium with 100 nm patterns made by this process, the out-of-plane coercivity was measured to be 5 fold larger than its in-plane value. The deposition-last process may be a promising way to achieve ultra-high density patterned media.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 기술교육전문연구회
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• pp.82-85
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• 2003

This dissertation describes an optimization method for fabricating thick films with superconducting YBCO powders by electrophoresis technique. The lateral alternating applied voltage caused to shake the superconducting powder vertically to the deposition field during the process of the oriented deposition so that it was deposited along the c-axis on the silver tape with shaky-aligned EPD. As the result, the optimized thin film fabrication method was obtained to get more dense and uniform surface morphology as well as the improved critical current density. For commercial utilization and efficiency, in this dissertation, alternating voltage of 25-120 V/cm in frequency of 60Hz was proposed to apply it as a subsidiary source for shaky-flow deposition so that the fabricated thin film showed uniform surface morphology with less voids and cracks and $T_{c.zero}$ of 90 K and the critical current density of $3419A/cm^2$.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1243-1245
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• 1994

SiN films were deposited in $Si_2H_6$(99.9%), $NH_3$(99.99%) gas mixture with carrier gas $N_2$ on Si substrate by ArF Excimer Laser CVD. SiN film deposition conditions that are substrate temperature and Laser average power were varied in order to investigate the dependence of SiN film on the condition. A post-deposition anneal was performed to examine variation of fixed charge density in the films. The deposition rate was increased as the substrate temperature and Laser power were increased during film deposition. The refractive index was increased with increasing substrate temperature, but it didn't have the dependence on Laser power. The fixed charge density was decreased when a post-deposition anneal was performed.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2000년도 추계학술발표회 초록집
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• pp.12-12
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• 2000

This paper investigated the effect of the film deposition rate for $CrN_x$ microstructure and mechanical properties. For these purpose, pure Cr an stoichiometric CrN films were deposited with various target power density on Si hardened M2 tool steel. The variation of ni trogen concentration in $CrN_x$ f analyzed by AES and deposition rate was calculated by measuring of thickness using ${\alpha}-step$ profilometer. The microstructure was analyzed by X-Ray Diffract and Scanning Electron Microscopy(SEM), and mechanical properties were evalua residual stress, microhardness and adhesion tests. Deposition rate of Cr and CrN increased as an almost linear function of target power density from $0.25\mu\textrm{m}/min$ and $0.15\mu\textrm{m}/min$ to $0.43\mu\textrm{m}/min$. Residual stresses of Cr and CrN films were from tensi Ie to compressive stress with an increase of deposi tion rate a compressive stresses were increased as more augmentation of deposition r maximum hardness value of $2300kg/\textrm{mm}^2$ and the best adhesion strength correspond HF 1 were obtained for CrN film synthesized at the highest target densitY($13.2W/\textrm{mm}^2$) owing to high residual compressive stress and increasing mobility.

• 한국초전도ㆍ저온공학회논문지
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• 제10권2호
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• pp.12-15
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• 2008

Nano-sized dots have been formed on the buffered metal substrates using the novel approach of the electro-spray deposition, to modulate the substrate surface and induce the columnar defects in REBCO films grown on it. The $BaZrO_3$ precursor solution was synthesized and electro-sprayed out onto the negatively charged substrate surface. Using the electrostatic force, nano-sized dots can be grown and uniformly distributed on the buffered metal substrate. The height of BZO nanodots was observed above the 200nm, which are beneficial to induce the columnar defects onto the BZO as a seed. The density of BZO nanodots was also investigated and ${\sim}7.8/{\mu}m^2$ was obtained. As the deposition distance of electro-spray was shortened there was ${\sim}8times$ increase of density of nanodots. The optimization of process variables in electro-spray deposition are discussed in respect to the superconducting REBCO films processed by the Metal-Organic Deposition with the effective flux pinning properties.

• Progress in Superconductivity
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• 제11권1호
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• pp.62-66
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• 2009

Introduction of proper impurity into $YBa_2Cu_3O_{7-x}$ (YBCO) thin films is an effective way to enhance its flux-pinning properties. We investigate effect of $Y_2O_3$ nanoparticles on the critical current density $J_c$ of the YBCO thin films. The $Y_2O_3$ nanoparticles were created perpendicular to the film surface (parallel with the c-axis) either between YBCO and substrate or on top of YBCO, YBCO/$Y_2O_3$/LAO or $Y_2O_3$/YBCO/STO, by pulsed laser deposition. The deposition temperature of the YBCO films were varied ($780^{\circ}C$ and $800^{\circ}C$) to modify surface morphology of the YBCO films. Surface morphology characterization revealed that the lower deposition temperature of $780^{\circ}C$ created nano-sized holes on the YBCO film surface which may behave as intrinsic pinning centers, while the higher deposition temperature produced much denser and smoother surface. $J_c$ values of the YBCO films with $Y_2O_3$ particles were either remained nearly the same or decreased for the samples in which YBCO is grown at $780^{\circ}C$. On the other hand, $J_c$ values were enhanced for the samples in which YBCO is grown at higher temperature of $800^{\circ}C$. The difference in the effect of $Y_2O_3$ can be explained by the fact that the higher deposition temperature of $800^{\circ}C$ reduces intrinsic pinning centers and $J_c$ is enhanced by introduction of artificial pinning centers in the form of $Y_2O_3$ nanoparticles.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2014년도 추계학술대회 논문집
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• pp.273-273
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• 2014

Quantum-dot sensitized solar cells (QDSCs) are an emerging class of solar cells owing to their easy fabrication, low cost and material diversity. Despite of the fact that the maximum conversion efficiency of QDSCs is still far less than that of Dye-Sensitized Solar Cells (>12 %), their unique characteristics like Multiple Exciton Generation (MEG), energy band tune-ability and tendency to incorporate multiple co-sensitizers concurrently has made QDs a suitable alternative to expensive dyes for solar cell application. Lead Sulfide (PbS) Quantum dot sensitized solar cells are theoretically proficient enough to have a photo-current density ($J_{sc}$) of $36mA/cm^2$, but practically there are very few reports on photocurrent enhancement in PbS QDSCs. Recently, $Hg^{2+}$ incorporated PbS quantumdots and Cadmium Sulfide (CdS) co-sensitized PbS solarcells are reported to show an improvement in photo-current density ($J_{sc}$). In this study, we explored the efficacy of $In_2S_3$ as an interfacial layer deposited through SILAR process for PbS QDSCs. $In_2S_3$ was chosen as the interfacial layer in order to avoid the usage of hazardous CdS or Mercury (Hg). Herein, the deposition of $In_2S_3$ interfacial layer on $TiO_2$ prior to PbS QDs exhibited a direct enhancement in the photo-current (Isc). Improved photo-absorption as well as interfacial recombination barrier caused by $In_2S_3$ deposition increased the photo-current density ($J_{sc}$) from $13mA/cm^2$ to $15.5mA/cm^2$ for single cycle of $In_2S_3$ deposition. Increase in the number of cycles of $In_2S_3$ deposition was found to deteriorate the photocurrent, however it increased $V_{oc}$ of the device which reached to an optimum value of 2.25% Photo-conversion Efficiency (PCE) for 2 cycles of $In_2S_3$ deposition. Effect of Heat Treatment, Normalized Current Stability, Open Circuit Voltage Decay and Dark IV Characteristics were further measured to reveal the characteristics of device.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.297-297
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• 2008

Buffer layers play an important role in the development of high critical current density coated conductor. $LaMnO_3$, $SrTiO_3$ and $BaZrO_3$ buffer layers were compatible with MgO surfaces and also provide a good template for growing high current density REBCO(RE=Rare earth) films. Systematic studies on the influences of pulsed laser deposition parameters (deposition temperature, deposition pressure, processing gas, laser energy density, etc.) on microstructure and texture properties of $LaMnO_3$, $SrTiO_3$ and $BaZrO_3$ films as buffer layer deposited on ion-beam assisted deposition MgO (IBAD_MgO) template by pulse laser deposition method, were carried out. These results will be presented together with the discussion on the possible use of this material in HTS coated conductor as buffer.

• 한국전기전자재료학회논문지
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• 제18권9호
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• pp.793-797
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• 2005

This study introduces Electro-chemical Mechanical Deposition(ECMD) lot making Cu interconnect. ECMD is a novel technique that has ability to deposit planar conductive films on non-planar substrate surfaces. Technique involves electrochemical deposition(ECD) and mechanical sweeping of the substrate surface Preferential deposition into the cavities on the substrate surface nay be achieved through two difference mechanisms. The first mechanism is more chemical and essential. It involves enhancing deposition into the cavities where mechanical sweeping does not reach. The second mechanism involves reducing deposition onto surface that is swept. In this study, we demonstrate ECMD process and characteristic. We proceeded this experiment by changing of distribution of current density on divided water area zones and use different pad types.