• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.02a
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• pp.287-290
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• 2003

For microwave device applications, c-axis oriented high temperature superconducting YBa$_2$Cu$_3$O$_{7-{\delta}}$ (HTS-YBCO) epitaxial thin films on the r-cut sapphire substrate(Al$_2$O$_3$) were prepared. In order to reduce the lattice mismatch with a substrate and to enhance the crystallity of HTS thin films, CeO$_2$ buffer layer on the r-cut sapphire substrate was grown by the RF-magnetron sputtering. The YBCO films on the CeO$_2$ buffer layer were deposited using the pulsed-laser deposition (PLD) method. These HTS YBCO /CeO$_2$/Al$_2$O$_3$ multilayer thin films(30 $\times$ 30 mm$^2$) routinely exhibited a critical temperature(T$_{c}$) of 89 K from the R-T measurement. Using HTS YBCO/CeO$_2$ /Al$_2$O$_3$ multilayer thin film. We fabricated and characterized the microwave passive devices (planar type filters) with cryopack-age such as the coupled -line type low-pass filter (LPF) and the open-loop meander type bandpass filter (BPF).filter (BPF).).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05c
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• pp.291-294
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• 2003

The circuit substrate was made from the Low Temperature Cofired Ceramics(LTCC) that a $\varepsilon_\gamma$ was 7.8. Accumulated Varactor and the low noise transistor which were a Surface Mount Device-type element on LTCC substrate. Let passive element composed R, L, C with strip-line of three dimension in the multilayer substrate circuit inside, and one structure accumulate band-pass filter, resonator, a bias line, a matching circuit, and made it. Used Screen-Print process, and made Strip-line resonator. A design produced and multilayer-type VCO(Voltage Controlled Oscillator), and recognized a characteristic with the Spectrum Analyzer which was measurement equipment. Measured multilayer structure VCO is oscillation frequency 1292[MHz], oscillation output -28.38[dBm], hamonics characteristic -45[dBc] in control voltage 1.5[V], A phase noise is -68.22[dBc/Hz] in 100 KHz offset frequency. The oscillation frequency variable characteristic showed 30[MHz/V] characteristic, and consumption electric current is approximately 10[mA].

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.5
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• pp.347-350
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• 2013

By inserting a very thin metal layer of Ag between two outer oxide layers of amorphous silicon indium zinc oxide (SIZO), we fabricated a highly transparent SIZO/Ag/SIZO multilayer on a glass substrate. In order to find the optimized thickness of Ag layers, we investigated the variation of optical properties depending on Ag thickness. It was found that the transition of Ag layer from island formation to a continuous film occurred at a critical thickness. Continuity of the Ag film is very important for optical properties in SIZO/Ag/SIZO multilayer. With about 15 nm thick Ag layer, the multilayer showed a high optical transmittance of 80% at 550 nm and low emissivity in IR.

• Tribology and Lubricants
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• v.37 no.6
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• pp.240-245
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• 2021

Ceramic coatings with high hardness and excellent chemical stability have been successfully applied to various machine elements, tools, and implants. However, in the case of monolayer coating on soft substrates, a high-stress concentration at the interface between the coating and the substrate causes delamination of the coating layer. Recently, to overcome this problem, multilayer coatings with a metal layer with a low modulus of elasticity added between the ceramic and the substrate have been widely applied. This study presents the third part of a recent study and focuses on the effect of the number of coating layers on the Brinell hardness of multilayered coating with TiN/Ti, following the two previous studies on a new Brinell hardness test method for a coated surface and on the influence of substrate and coating thickness. Indentation analyses are performed using finite element analysis software, von Mises stress and equivalent plastic strain distributions, load-displacement curves, and residual indentation shapes are presented. The number of TiN/Ti layers considerably affect the stress distributions and indentation shapes. Moreover, the greater the number of TiN/Ti layers, the higher is the Brinell hardness. The stress and plastic strain distributions confirm that the multilayer coatings improve the wear resistance. The results are expected to be used to design and evaluate various coating systems, and additional study is required.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.658-659
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• 2006

Magnetron sputtered TiN, (Ti, Al)N and TiN/(Ti, Al)N multilayer coatings grown on cemented carbide substrates have been characterized by using electron probe microanalysis (EPMA), X-ray diffraction (XRD), scanning electron spectroscopy (SEM), nanoindentation, scratcher and cutting tests. Results show that TiN coating is bell mouth columnar structures, (Ti, Al)N coating is straight columnar structures and the modulation structure has been formed in the TiN/(Ti, Al)N multilayer coating. TiN/(Ti, Al)N multilayer coating exhibited higher hardness, better adhesion with substrate and excellent cutting performance compared with TiN and (Ti, Al)N coating.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.385-386
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• 2007

We prepared the Al doped ZnO coating Ag multilayer thin films on glass without substrate heating using FTS system. The structure of multilayer thin films has Al doped ZnO/Ag/Al doped ZnO(AZO/Ag/AZO). The thickness of top and bottom AZO thin films were fixed to 50 nm, respectively and controlled the thickness of Ag thin films with deposition time. As-doped multilayer thin films were prepared at 1mTorr and input power (DC) of 100W at room temperature. To investigate the film properties, we employed four-point probe, UVNIS spectrometer, X-ray diffractometer (XRD), scanning electron microscopy (SEM), Hall Effect measurement system and Atomic Force Microscope (AFM).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.9
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• pp.798-801
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• 2007

Multilayer transparent electrodes, having a much lower electrical resistance than the widely used transparent conducting oxide electrodes, were prepared by using radio frequency magnetron sputtering. The multilayer structure consisted of five layers, indium tin oxided (ITO)/zinc oxide (ZnO)/Ag/zinc oxide (ZnO)/ITO. With about 50 nm thick ITO films, the multilayer showed a high optical transmittance in the visible range of the spectrum and had color neutrality. The electrical and optical properties of ITO/ZnO/Ag/ZnO/ITO multilayer were changed mainly by Ag film properties, which were affected by the deposition process of the upper layer. Especially ZnO layer was improved to adhesion of Ag and ITO. A high quality transparent electrode, having a resistance as low as and a high optical transmittance of 91% at 550 nm, was obtained. It could satisfy the requirement for the flexible OLED and LCD.

• Journal of the Semiconductor & Display Technology
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• v.13 no.2
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• pp.13-16
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• 2014

We prepared the ITO/Ag multilayer thin films on soda-lime glass substrate by the Facing Target Sputtering System (FTS) at room temperature. To confirm the effect of Ag layer in ITO/Ag multilayer thin films, we have prepared various range of Ag layer in its thickness and investigated prior to the setting of ITO/Ag multilayer thin films. The thickness of Ag layer was controlled by the sputtering deposition time. Properties of as-prepared samples were investigated by using a four-point probe, UV-Visual spectrometer with a spectral visual range (400 - 800 nm) and X-ray diffractometer (XRD). As a result, the transmittance of as-prepared samples turned out to be very low in the visible range due to light-scattering on the surface of thin film as the thickness of Ag layer got increased. However, reduction of phenomenon of light-reflection in visual range was observed around 20nm of Ag thickness. We prepared the ITO/Ag multilayer thin film with a resistivity of about $8{\times}10^{-5}[{\Omega}-cm]$ and a transmittance of more than 80 % at 550 nm.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.7
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• pp.510-514
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• 2013

In order to prevent heat loss that occurs through the glass, low-emissivity (Low-E) coating methods with good insulating properties and high transmittance were used. InGaZnO/Ag/InGaZnO (IGZO/Ag/IGZO) multilayer thin films have been deposited on XG glass substrate by RF magnetron sputtering. Depending on the different thickness of Ag in multilayer films, the structural and optical properties of Low-E multilayer films were analyzed. By XRD analysis results, the multilayer thin films were observed to be amorphous structure regardless of Ag thickness. According to the AFM results, surface morphology of the multilayer films was observed and compared. Using UV-VIS spectroscopy, low emissivity property has been observed clearly with the transmittance of higher than 85% at visible range and lower than 30% at IR range.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.1
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• pp.27-32
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• 2021

In this study, we fabricated multilayer graphene on a glass substrate by stacking the monolayer graphene synthesized via chemical vapor deposition. The electrical sheet resistance and optical transmittance were evaluated to confirm the quality of the stacked multilayer graphene. Using the fabricated multilayer graphene/glass structure, we characterized its thermal radiative property in terms of the integrated emissivity. The integrated emissivity of the multilayer graphene/glass structure was tuned from 0.91 to 0.72 when the number of graphene layers was changed from 1 to 12. We also demonstrated that the emissivity tunability provided a way to control the apparent temperature of an object that can be used in infrared stealth applications.