• 센서학회지
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• 제22권2호
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• pp.105-110
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• 2013

We fabricated an a-IGZO thin film transistor (TFT) with AZO/Ag/AZO transparent multilayer source/drain contacts by rf magnetron sputtering. a-IGZO TFT with AZO/Ag/AZO multilayer S/D electrodes (W/L = 400/50 ${\mu}m$) showed a subs-threshold swing of 3.78 V/dec, a minimum off-current of $10^{-12}$ A, a threshold voltage of 0.41 V, a field effect mobility of $10.86cm^2/Vs$, and an on/off ratio of $9{\times}10^9$. From the ultraviolet photoemission spectroscopy, it was revealed that the enhanced electrical performance resulted from the lowering of the Schottky barrier between a-IGZO and Ag due to the insertion of an AZO layer and thus the AZO/Ag/AZO multilayer would be very appropriate for a promising S/D contact material for the fabrication of high performance TFTs.

• 한국통신학회논문지
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• 제25권5B호
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• pp.985-991
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• 2000

본 논문에서는 인덕터의 면적을 극소화시키고 인덕턴스와 Q값을 극대화시키기 위한 최적구조의 2GHz 자성박막 인덕터를 설계하고 제작하였다. Eddy-current 표피효과를 위해서 Co90Fe10와 SiO2의 multilayer를 사용하고, multilayer를 적용한 새로운 lumped 소자모델을 고려하여 최적설계를 수행하였다. 2GHz에서 동작하는 새로운 자성박막 인덕터는 photo-lithography와 lift-off기술을 이용하여 Si 기판위에 제작되었다. 50개 이상의 동일한 인덕터들의 주파수 특성은 RF Impedance Analyzer로, 자기공진주파수는 Vector Network 분석기(HP8510)로 측정되었다. 개발된 인덕터들은 1.8~2.3GHz 범위의 자기공진주파수, 47~68nH 범위의 L값, 그리고 1GHz이상의 주파수에서 70~80정도의 Q값을 가지므로 L과 Q가 극대화된 아주 우수한 최적구조의 소형(면적=30.8$\times$30.8mil2) 박막인덕터가 성공적으로 제작되었다.

• 한국재료학회지
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• 제30권6호
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• pp.285-291
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• 2020

Recent advances in technology using ultra-thin noble metal film in oxide/metal/oxide structures have attracted attention because this material is a promising alternative to meet the needs of transparent conduction electrodes (TCE). AZO/Ag/AZO multilayer films are prepared by magnetron sputtering for Cu₂ZnSn(S,Se)₄ (CZTSSe) of kesterite solar cells. It is shown that the electrical and optical properties of the AZO/Ag/AZO multilayer films can be improved by the very low resistivity and surface plasmon effects due to the deposition of different thicknesses of Ag layer between oxide layers fixed at AZO 30 nm. The AZO/Ag/AZO multilayer films of Ag 15 nm show high mobility of 26.4 ㎠/Vs and low resistivity and sheet resistance of 3.58^⁎10^-5 Ωcm and 5.0 Ω/sq. Also, the AZO/Ag (15 nm)/AZO multilayer film shows relatively high transmittance of more than 65 % in the visible region. Through this, we fabricated CZTSSe thin film solar cells with 7.51 % efficiency by improving the short-circuit current density and fill factor to 27.7 mV/㎠ and 62 %, respectively.

• 한국결정성장학회지
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• 제31권2호
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• pp.73-77
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• 2021

RF 마그네트론 스퍼터링 공정에 의해 Ga-doped ZnO 박막이 O2 및 Ar 분위기 하에서 증착 조건에 따라 합성되었으며, N2 분위기에서, 600℃에서 급속열처리(RTA)를 실시하였다. 증착된 ZnO : Ga 박막에 대해 두께를 측정하였고, XRD 패턴 분석에 의해 결정상을 조사하였으며, FE-SEM, AFM 이미지에 의해 박막의 미세구조를 관찰하였다. O2 및 Ar 분위기 기체 종류별로 형성된 박막들의 증착 조건에 따라 X-선 회절 패턴의 (002)면의 세기는 상당한 차이를 나타냈다. O2 조건에서는 Ga doping이 이루어진 단일 박막의 경우에서는 강한 세기의 회절피크가 관찰되었다. O2 및 Ar 조건에서는 Ga doping이 이루어진 다층박막의 경우에서는 다소 약한 세기의 (002) 면의 피크만을 나타내었다. FE-SEM image에서는 박막의 표면입자의 크기는 두께가 증가함에 따라 입자크기가 다소 증가하는 것으로 관찰되었다. O2 및 Ar 분위기 조건 하에서, Ga doping이 이루어진 다층박막의 경우에서는, 비저항은 6.4 × 10-4Ω·cm을 나타냈고, O2 분위기 조건하에서, Ga doping이 이루어진 단일 박막의 경우에서는 저항값이 감소하였고, Ga-doped ZnO 박막의 두께가 2 ㎛로 증가하면서 저항이 감소하였으며, 1.0 × 10-3 Ω·cm의 비교적 낮은 비저항 값을 나타내었다.

• 한국레이저가공학회지
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• 제7권2호
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• pp.11-18
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• 2004

We propose a novel application of optical coherence tomography (OCT) to monitor pit formation in laser irradiated optical storage materials. A multilayer optical storage recordable compact disk, is composed of multiple layers, each of different structure. Disks were irradiated with aQ-Switched Nd:YAG laser with an energy of 373 mJ. Post-irradiated disks were evaluated by OCT and those images were compared with optical microscopy. Our results indicate that OCT is a useful instrument to investigate pit formation in multilayer optical storage disks and might also provide information to optimize optical memory technology.

• 열처리공학회지
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• 제13권5호
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• pp.324-329
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• 2000

Microstructure, mechanical and fatigue behaviors of TiCN and TiN/TiCN thin films, deposited on quenched and tempered STD61 tool steel, were investigated by using XRD, XPS, hardness, adhesion and fatigue tests. The TiCN thin film is grown along the (100), (111) orientation, whereas the TiN/TiCN thin film is grown along the (111) orientation. The preferred orientation of TiN/TiCN thin film strongly depends on the TiN buffer layer whose orientation is (111), as is well-known. The TiN/TiCN thin film showed the higher adhesion compared with TiCN single layer because the TiN buffer layer, having good toughness, reduces the effects of the lower hardness of substrate. In the high cycle tension-tension fatigue test, the fatigue life of the TiCN and the TiN/TiCN coated steel increased approximately two to four times and five to nine times respectively compared with uncoated specimens. The TiN buffer layer in multilayer thin films plays an important role in reducing residual stress and fatigue crack initiation, and then in restraining the fatigue propagation.

• 전기학회논문지
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• 제65권12호
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• pp.2014-2018
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• 2016

Transparent, conductive electrode films, showing the particular characteristics of good conductivity and high transparency, are of considerable research interest because of their potential for use in opto-electronic applications, such as smart window, photovoltaic cells and flat panel displays. Multilayer transparent electrodes, having a much lower electrical resistance than widely-used transparent conducting oxide electrodes, were prepared by using RF/DC magnetron sputtering system. The multilayer structure consisted of three layers, [NiInZnO(NIZO)/Ag/NIZO]. The optical and electrical properties of the multilayered NIZO/Ag/NIZO structure were investigated in relation to the thickness of each layer. The optical and electrical characteristics of multilayer structures have been investigated as a function of the Ag and NIZO film thickness. High-quality transparent conductive films have been obtained, with sheet resistance of $9.8{\Omega}/sq$ for Ag film thickness of 8 nm. Also the multilayer films of inserted Ag 8 nm thickness showed a high optical transmittance above 93% in the visible range. The electrical and optical properties of the new multilayer films were mainly dependent on the thickness of Ag insertion layer.

• 한국전기전자재료학회논문지
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• 제30권3호
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• pp.162-169
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• 2017

Indium tin oxide (ITO) thin films show a low sheet resistance and high transmittance in the visible range of the spectrum. Therefore, they play an important role as transparent electrodes for flat panel displays. However, their resistivity is rather high for use as a transparent electrode in large displays. One way to improve electrical and optical properties in large displays is to use ITO/Ag/ITO multilayer films. ITO/Ag/ITO multilayer films have lower sheet resistance than single layer ITO films with the same thickness. Prior to the ITO/Ag/ITO multilayer experiments, optimal condition for thickness change are necessary. Their thicknesses were deposited differently in order to analyze electrical and optical properties. However, when optimal single film characteristics are applied to ITO/Ag/ITO multilayer films, other phenomena appeared. After analyzing the electrical and optical properties by changing ITO and Ag film thickness, ITO/Ag/ITO multilayer films were optimized. By combining ITO film at $586\;{\AA}$ and Ag film at 10 nm, the ITO/Ag/ITO multilayer films showed optimized high optical transmittance of 87.65%, and the low sheet resistance of $5.5{\Omega}/sq$.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.201-201
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• 2006

In this study the glass transition temperature in thin polymer films has been studied. Ellipsometry has been used to measure $T_{g}$ of thin film as a function of film thickness. Empirical equation has been proposed to fit the measured $T_{g}$ pattern with thickness. Also, a continuous multilayer model was proposed and derived to describe the effect of surface on the observed $T_{g}$ reduction in thin films, and the depth-dependent $T_{g}$ profile was obtained. These results showed that $T_{g}$ at the top surface was much lower than the bulk $T_{g}$ and gradually approached the bulk $T_{g}$ with increasing distance from the edge of the film. The model and equation were modified to apply for the polymer coated on the strongly favorable substrate and the freely standing film.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2003년도 학술대회 논문집
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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).).