• Proceedings of the Optical Society of Korea Conference
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• 2003.07a
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• pp.36-37
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• 2003

To increase the high-density data storage, a new technique of Super-resolution near-field structure (Super-RENS) consisted of glass／SiN／Sb or AgOx／SiN has been proposed and investigated intensively as a promising structure for near-field ultrahigh-density optical storage. Hence it is important to determine the optical properties of AgOx by using ellipsometry. AgOx thin films were prepared by using magnetron sputtering technique while oxygen flow rate was varied, and the film growth of AgOx were monitored by using in situ ellipsometer. (omitted)

• Journal of Electrochemical Science and Technology
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• v.3 no.4
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• pp.185-189
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• 2012

A.c. impedances of mechanically polished CP-Ti specimens were measured at open-circuit potential (OCP) with immersion time and under applied anodic potentials between -0.2 and 1 $V_{Ag/AgCl}$ in 0.1 M NaOH solution. Capacitances of native oxide films ($C_{ox,na}$) grown naturally and capacitances of anodic oxide films ($C_{ox,an}$) formed under applied anodic potentials were obtained to examine the growth of native and anodic oxide films in 0.1 M NaOH solution and how to use $C_{ox,na}$ for the surface area measurement of Ti specimen. $1/C_{ox,na}$ and $1/C_{ox,an}$ appeared to be linearly proportional to OCP and applied potential ($E_{app}$), with proportional constants of 0.086 and 0.051 $uF^{-1}\;V^{-1}$, respectively. The $C_{ox,na}$ also appeared to be linearly proportional to geometric surface area of the mechanically polished CP-Ti fixture specimen, with proportional constants of 11.3 and $8.5{\mu}F\;cm^{-2}$ at -0.45 $V_{Ag/AgCl}$ and -0.25 $V_{Ag/AgCl}$ of OCPs, respectively, in 0.1 M NaOH solution. This linear relationship between $C_{ox,na}$ and surface area is suggested to be applicable for the measurement of real surface area of Ti specimen.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.424.2-424.2
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• 2014

Ag-modified BiOX (X=Cl, Br and I) nanoplates were synthesized by an ion-exchange reaction. We examined the fundamental properties by scanning electron microscopy (SEM), electron transmission microscopy (TEM), X-ray diffraction, UV-visible absorption, Fourier-transform infrared and photoluminescence spectroscopy. The adsorption and photocatalytic performances of the catalysts were tested with dyes under UV and visible light. A chemical scavenger method was employed to test the roles of active species (${\cdot}OH$, ${\cdot}O2-$ and h+) and understand photodegradation mechanism. Photoluminescence spectroscopy was used to examine ${\cdot}OH$ radical formation using terephthalic acid during photoirradiation.

• Journal of the Microelectronics and Packaging Society
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• v.31 no.2
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• pp.1-8
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• 2024

Bonding wires are composed of conductive metals of Au, Ag & Cu with excellent electrical conductivities for transmitting power and signals to wafer chips. Wire metals do not provide electrical insulation, adhesion promoter and corrosion passivation. Adhesion between metal wires is extremely weak, which is responsible for wire cut failures during thermal cycling. Organic coating for electrical insulation does not satisfy bondability and manufacturability, and it is complex to apply very thin organic coating on metal wires. Automotive packages require enhanced reliability of packages under harsh conditions. LED and power packages are susceptible to wire cut failures. Contrary to conventional OCB behaviors, forming gas was not required for free air ball formation for both Ag and Pd-coated Cu wires with Al₂O₃ passivation.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.238-238
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• 2012

Ag (silver)의 일함수는 T-OLED (Top Emission Organic Light Emitting Diode)의 전극소자로 사용하기에는 다소 낮다는 단점이 있다(~4.3 eV). 이러한 단점을 해결하기 위한 대안으로 Ag 박막의 표면을 플라즈마 처리, UV 처리 및 열처리를 통하여 일함수를 높이는 연구가 진행 되어왔다(>5.0 eV). 하지만 현재의 대부분 연구는 후 처리된 박막의 일함수에 초점을 맞춰 연구가 진행 되어 박막의 nano-mechanical property에 대한 연구는 매우 부족하다. 따라서 본 논문에서는 AgOx 박막의 nano-mechanical property에 초점을 맞춰 분석을 실시하였다. 연구에 사용된 샘플은 Ag 박막을 유리기판 위에 rf-magnetron sputter 장치를 이용하여 100 W의 power로 150 nm 두께로 증착하였다. 증착된 Ag 박막은 $O_3$ 발생 UV 램프를 이용하여, 다양한 시간동안 UV 처리하였다(0~9분). 증착된 샘플은 Four-point probe, nanoindenter 장비를 이용하여 nano-mechanical property를 분석하였다. 실험 결과 UV 처리 시간이 0, 1분에서 면저항이 0.16, 0.50 ${\Omega}$/sq로 급격한 변화가 나타났으나, 반면 3분 이후 9분의 샘플의 경우, 0.55 ${\Omega}$/sq에서 0.24, 0.20, 0.15 ${\Omega}$/sq로 감소하여 전기적 특성변화를 볼 수 있었다. 또한 nanoindenting 결과 UV 처리한 박막의 극 표면 경도 값의 변화는 0~5분 처리한 샘플의 경우, 물리적인 경도가 증가하는 형태를 보이며 UV 처리를 5분간 했을때 7.89 GPa로 최고의 경도를 가진다. 그 이후부터는 6.97, 3.46 GPa의 결과로 박막의 경도가 감소되는 결과를 얻었다. 이러한 결과로부터 Ag 박막의 후처리에 따른 Ag 물질의 산화 및 결정상태에 따라 박막 내에 존재하는 residual stress를 분석할 수 있다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1990.10a
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• pp.26-30
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• 1990

Bi$\_$0.7/Pb$\_$0.3/Sr$_1$Ca$_1$Cu$\_$1.8/Ox thick films were screen printed on magnesia(MgO), silver and yttrium stabilized zirconia (YSZ) substrates and were sintered in a boat with cover to prevent the evaporation. The high-Tc phase increase and the low-Tc phase and Ca$_2$PbO$_4$ decrease with an increase in sintering temperature from 835$^{\circ}C$ to 860$^{\circ}C$. YSZ substrate interact strongly with the oxide resulting in poor superconductor, while the Ag and MgO substrates were satisfactory to make screen printed superconductors. The Bi$\_$0.7/Pb$\_$0.3/Sr$_1$Ca$_1$Cu$\_$1.8/Ox thick films screen printed both on Ag and MgO substrates show high Tc phase of ~85% and Tc of 96K.

• Journal of the Korean Ceramic Society
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• v.31 no.12
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• pp.1483-1490
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• 1994

YBa2Cu3Ox-Ag(YBCO-Ag) thick films were fabricated on the zirconia substrate by a screen printing method. The starting powder was a mixture of YBCO, prepared by a coprecipitation in oxalic acid, and Ag2O. The influence of heat treatment conditions on properties of thick films was investigated. It was observed that Jc of thick films was directly proportional to the orientation factor of thick films and the optimimum preparation condition was the heat treatment of thick films at 100$0^{\circ}C$ for 3 min in O2. The improvement of Jc by the addition of Ag was considered as a result of the suppression of microcracks in the films.

• Journal of the Korean Chemical Society
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• v.65 no.2
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• pp.125-132
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• 2021

An electrochromic nickel oxide thin film was fabricated on a flexible PET/ITO substrate using a nanocrystallite- dispersed coating sol and bar coater. Nanocrystalline NiOx of 3-4 nm crystallite size was first synthesized by base precipitation and thermal conversion. This NiOx nanocrystallite powder was mechanically dispersed in an alcoholic solvent mixed with a silane binder to prepare a coating sol for thin film. This sol method is different from the normal sol-gel method in that it does not require the conversion of precursor by heat treatment. Therefore, this method provides a very facile method to prepare NiOx thin films on any kind of substrate and it can be easily applied to mass production. The electrochromic performance of this NiOx thin film on PET/ITO electrode with a thickness of about 400 nm was investigated in a nonaqueous LiClO4 electrolyte solution by cyclic voltammetric and repeated chronoamperometric measurements in conjunction with spectrophotometry. The visible light modulation of 44% and the colorization efficiency of 41 ㎠/C at 550 nm were obtained at the step potentials of -0.8/+1.2 V vs Ag and a duration of 30 s.

• Journal of the Semiconductor & Display Technology
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• v.23 no.1
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• pp.1-6
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• 2024

Recently, artificial neural networks have been playing a crucial role and advancing across various fields. Artificial neural networks are typically categorized into feedforward neural networks and recurrent neural networks. However, feedforward neural networks are primarily used for processing static spatial patterns such as image recognition and object detection. They are not suitable for handling temporal signals. Recurrent neural networks, on the other hand, face the challenges of complex training procedures and requiring significant computational power. In this paper, we propose memristors suitable for an advanced form of recurrent neural networks called reservoir computing systems, utilizing a mask processor. Using the characteristic equations of Ti/TiOx/TaOy/Pt, Pt/TiOx/Pt, and Ag/ZnO-NW/Pt memristors, we generated current-voltage curves to verify their memristive behavior through the confirmation of hysteresis. Subsequently, we trained and inferred reservoir computing systems using these memristors with the NIST TI-46 database. Among these systems, the accuracy of the reservoir computing system based on Ti/TiOx/TaOy/Pt memristors reached 99%, confirming the Ti/TiOx/TaOy/Pt memristor structure's suitability for inferring speech recognition tasks.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.54.1-54.1
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• 2010

산화물 기반의 TFT는 유리, 금속, 플라스틱 등 기판 종류에 상관없이 균일한 제작이 가능하며, 상온 및 저온에서 대면적으로 제작이 가능하고, 저렴한 비용으로 제작 가능하다는 장점 때문에 최근 많은 연구가 이루어지고 있다. 현재 TFT 물질로 많이 연구되고 있는 산화물은 ZnO (3.4 eV)나 InOx (3.6 eV), GaOx (4.9 eV), SnOx(3.7 eV)등의 물질과 각각의 조합으로 구성된 재료들이 주로 사용되고 있으며, 가장 많은 연구가 이루어진 ZnO 기반의 TFT는 mobility와 switching 속도에서 우수한 특성을 보이나, 트렌지스터의 안정성이 떨어지는 것으로 보고 되고 있다. 그러나 IGZO 물질의 경우 결정학적으로 비정질이며 상온 및 저온에서 대면적으로 제작이 가능하고, 높은 전자 이동도의 특성을 가지고 있는 장점 때문에 최근 차세대 산화물 트렌지스터로 각광받고 있다. IGZO TFT 소자의 경우 Ag, Au, In, Pt, Ti, ITO 등 다양한 전극 물질이 사용되고 있는데, 이들 중 active channel과 ohmic contact을 이루는 Al, Ti, Ag의 적용을 통해 향상된 성능을 얻을 수 있다. 하지만 이들 전극 재료는 TFT 소자 제작시 필수적인 열처리 공정에 노출되면서 active channel 과 전극 사이 계면에 문제점을 야기할 수 있다. 특히, Ti의 경우 산화가 잘되기 때문에 전극계면에 TiO2를 형성하여 contact resistance의 큰 영향을 미치는 것으로 보고 되고 있다. 본 연구에서는 ohmic 전극재료인 Ti 또는 Ti/Au를 적용하여 TFT 소자 제작 및 특성에 대한 평가를 진행했으며, 열처리에 따른 전극과 IGZO 계면 사이의 미세구조와 전기적인 특성간의 상관관계를 연구하였다. 이를 통해, 소자 제작 공정을 최적화하고 신뢰성 있는 소자 특성을 얻을 수 있었다.