• Title/Summary/Keyword: low-k materials

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Characterization of Sol-Gel Derived Antimony-doped Tin Oxide Thin Films for Transparent Conductive Oxide Application

  • Woo, Dong-Chan;Koo, Chang-Young;Ma, Hong-Chan;Lee, Hee-Young
    • Transactions on Electrical and Electronic Materials
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    • v.13 no.5
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    • pp.241-244
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    • 2012
  • Antimony doped tin oxide (ATO) thin films on glass substrate were prepared by the chemical solution deposition (CSD) method, using sol-gel solution synthesized by non-alkoxide precursors and the sol-gel route. The crystallinity and electrical properties of ATO thin films were investigated as a function of the annealing condition (both annealing environments and temperatures), and antimony (Sb) doping concentration. Electrical resistivity, carrier concentration, Hall mobility and optical transmittance of ATO thin films were improved by Sb doping up to 5~8 mol% and annealing in a low vacuum atmosphere, compared to the undoped tin oxide counterpart. 5 mol% Sb doped ATO film annealed at $550^{\circ}C$ in a low vacuum atmosphere showed the highest electrical properties, with electrical resistivity of about $8{\sim}10{\times}10^{-3}{\Omega}{\cdot}cm$, and optical transmittance of ~85% in the visible range. Our research demonstrates the feasibility of low-cost solution-processed transparent conductive oxide thin films, by controlling the appropriate doping concentration and annealing conditions.

Synthesis of Nano-Sized Cu Powder by PVA Solution Method and Thermal Characteristics of Sintered Cu Powder Compacts (PVA 용액법을 통한 나노 Cu 분말합성 및 소결체의 열적 특성)

  • Oh, Bok-Hyun;Ma, Chung-Il;Lee, Sang-Jin
    • Korean Journal of Materials Research
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    • v.30 no.2
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    • pp.93-98
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    • 2020
  • Effective control of the heat generated from electronics and semiconductor devices requires a high thermal conductivity and a low thermal expansion coefficient appropriate for devices or modules. A method of reducing the thermal expansion coefficient of Cu has been suggested wherein a ceramic filler having a low thermal expansion coefficient is applied to Cu, which has high thermal conductivity. In this study, using pressureless sintering rather than costly pressure sintering, a polymer solution synthesis method was used to make nano-sized Cu powder for application to Cu matrix with an AlN filler. Due to the low sinterability, the sintered Cu prepared from commercial Cu powder included large pores inside the sintered bodies. A sintered Cu body with Zn, as a liquid phase sintering agent, was prepared by the polymer solution synthesis method for exclusion of pores, which affect thermal conductivity and thermal expansion. The pressureless sintered Cu bodies including Zn showed higher thermal conductivity (180 W/m·K) and lower thermal expansion coefficient (15.8×10-6/℃) than did the monolithic synthesized Cu sintered body.

Tribological Behavior of Automotive Brake Pads with Different Sizes of zircon Particles (마찰재에 사용되는 지르콘($ZrSiO_4$) 입자의 크기에 따른 마찰특성)

  • Hong, Young-Suk;Ko, Kil-Ju;Park, Sang-Jin;Jang, Ho
    • Tribology and Lubricants
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    • v.18 no.3
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    • pp.204-210
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    • 2002
  • Automotive brake pads with four different sizes of zircon particles (average sizes of 1㎛, 6㎛, 75㎛, and 140㎛, respectively) were investigated to evaluate the size effect of abrasive particles on friction performance. Results showed that the brake pads with the larger size of zircon particles tend to show better frictional stability and low pad wear. However, the rotor surface was severely abraded in the case of using larger zircon particles. On the other hand, the small zircon particles in the pads showed the fast increase of the coefficient of friction with friction force oscillation and the tendency was pronounced at low sliding speeds. The brake pads with small particle sizes also exhibited strong fade phenomena at elevated temperatures.

Spectral Classification of Man-made Materials in Urban Area Using Hyperspectral Data

  • Kim S. H.;Kook M. J.;Lee K. S.
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.10-13
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    • 2004
  • Hyperspectral data has a great advantage to classify various surface materials that are spectrally similar. In this study, we attempted to classify man-made materials in urban area using Hyperion data. Hyperion imagery of Seoul was initially processed to minimize radiometric distortions caused by sensor and atmosphere. Using color aerial photographs. we defined seven man-made surfaces (concrete, asphalt road. railroad, buildings, roof, soil, shadow) for the classification in Seoul. The hyperspectral data showed the potential to identify those manmade materials that were difficult to be classified by multispectral data. However. the classification of road and buildings was not quite satisfactory due to the relatively low spatial resolution of Hyperion image. Further, the low radiometric quality of Hyperion sensor was another limitation for the application in urban area.

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Electrical Properties of Organic Materials as Low Dielectric Constant Materials

  • Oh Teresa;Kim Hong Bae;Kwon Hak Yong;Son Jae Gu
    • Proceedings of the Korean Society Of Semiconductor Equipment Technology
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    • 2005.05a
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    • pp.67-72
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    • 2005
  • The bonding structure of organic materials such as fluorinated amorphous carbon films was classified into two types due to the chemical shifts. The electrical properties of fluorinated amorphous carbon films also showed very different effect of two types notwithstanding a very little difference. Fluorinated amorphous carbon films with the cross-link breakage structure existed large leakage current resulting from effect of the electron tunneling. Increasing the cation due to the electron-deficient group increased the barrier height of the films with the cross-link amorphous structure, therefore the electric characteristic of the final materials with low dielectric constant was also improved. The lowest dielectric constant is 2.3 at the sample with the cross-link amorphous structure.

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Research Progress of Antibiotic Pollution and Adsorption Materials in Aquatic environment

  • Zheng, Kun;Deng, ChengXun;Deng, Xu;Yu, ZhiMin
    • Journal of Urban Science
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    • v.8 no.2
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    • pp.1-5
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    • 2019
  • China is the great powers of use and production of antibiotics.The current process of sewage treatment plants can not effectively remove antibiotics in water. Chinese scholars have detected different kinds of antibiotics in major waters of the country, which have potential harm to human body. Among all kinds of antibiotic treatment technologies, adsorption removal technology has the advantages of simple operation, low cost and high removal efficiency. It is a widely concerned antibiotic removal technology. However, at present, few materials have been put into practical application, and more materials with low cost and high efficiency need to be found. Different adsorptive materials have different adsorptivity to different antibiotics. For different antibiotics, different adsorptive materials can be integrated in the future, and the theory can be extended to application.