• Title/Summary/Keyword: Vaccum

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Surface Elemental change of dental Ni-Cr Alloy for Porcelain after Heat Treatment (도재용 Ni-Cr 합금표면의 열처리후 원소성분 변화)

  • Nam, Sang-Yong
    • Journal of Technologic Dentistry
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    • v.17 no.1
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    • pp.5-9
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    • 1995
  • This study was carried out by obsorving to the conditions of an oxide on the surface of alloy according to the conditions of its heat treatment and analysing the change in composition on its surface. The result of this study is summarized as fellows. 1. It was shown that the higher the more the generated metal oxide while the higher the temperature of heat treatment. 2. The metal oxide was manily composed of Ni and Cr oxides. 3. The Ni composition indicated reduction while the higher the heat treatment in vaccum condition. 4. The Cr composition indicated increase while the higher the heat treatment in vaccum condition.

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Strong Electric Field in Ultra High Vaccum

  • Shin, Sunghwan;Kim, Youngsoon;Kang, Hani;Kang, Heon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.262-262
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    • 2013
  • In surface chemistry area, many scientists studied the electrochemical reaction by changing work-function of metal; however, these methods had the weakness that it did not create the electric field. Unlike earlier studies, our capacitor-method makes a strong electric field in ice film. This electric field was induced by soft landing $Cs^+$ ions on ice film, and the strength was measured by the vibrational Stark shift of acetonitrile. In our system, the electric field strength is $10^9$ V/m and it is almost same in the electrochemical cell. This capacitor model provides new method to investigate the electrochemical reaction in vacuum system.

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Correlation between Capacitance and Structure-optical Properties of Semiconductor with Zero Leakage Current (누설전류 Zero인 반도체 물질의 구조적 광학적 특성과 전도성과의 상관성)

  • Yun, Tae Hwan;Oh, Teresa
    • Journal of the Semiconductor & Display Technology
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    • v.14 no.3
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    • pp.27-31
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    • 2015
  • It was the electrical properties of ZnS treated by the annealing in a vaccum and an atmosphere conditions to reseached the leakage current effect of semiconductor devices. Most samples were shown the non-linear with unipolar properties, but the ZnS annealed at $100^{\circ}C$ in a vaccum was only observed no leakage current in a range of -20 V< voltage < 15 V. The crystallinity of ZnS with no leakage current was improved and optical property was also improved. Because the ambipolar characteristics and low leakage currents originated from the extension effect of a depletion width by electron-hole combination in the depletion layer.

A Study on the Effect of Si Surface on Diamond Film Growth by AES (Diamond 박막 성장에 미치는 Si 표면 영향의 AES에 의한 연구)

  • Lee, Cheol-Ro;Sin, Yong-Hyeon;Im, Jae-Yeong;Jeong, Gwang-Hwa;Cheon, Byeong-Seon
    • Journal of the Korean Vacuum Society
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    • v.2 no.2
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    • pp.199-208
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    • 1993
  • The effect of nucleation free energy related to Si surface states on diamond film growth behavior has been studied. Ar first, the three kinds of diamond thin films (A, B, C) were deposited on various Si substrates (A-Si, B-Si, C-Si) whose surfaces were polished with 1 ${\mu}m$ diamond paste, 6 ${\mu}m$ Al_2O_3$ powder and 12 ${\mu}m$ Al_2O_3$ powder respectively. And then, relative nucleation free energy calculated is ${\Delta}G_{A-Si}<{\Delta}G_{B-Si}<{\Delta}G_{C-Si}$. Although there are some difference in grain size, shape and nucleated size, the thin films on A-Si and B-Si were diamond including a small amount of DLC which was confirmed by AES, SEM, XRD, and RHEED. Namely, the diamonds of films (B) were not nucleated in scratches but in dents and larger in grain size compare with the film (C) of which diamond sere nucleated not only scratches but also dents. And, the sphere diamond which is not general shape was grown on C-Si. After all, the sphere was turned out to be the diamond including much graphite as a result of the AES in situ depth profiling. Consequently, the diamond shape and quality grown on Si were Changed from the crystal which the (100) and (110) planes were predominent to the crystal in which (111) plane was predominent, and newt to sphere shape diamond including much graphite according as the nucleation free energy increases.

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Drypumping of Semiconductor Processes-Clean and Arduous Applications (반도체 공정에서의 건식 펌프)

  • Troup, A.P.
    • Journal of the Korean Vacuum Society
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    • v.1 no.2
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    • pp.302-313
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    • 1992
  • 10-9Torr 정도의 압력에서 작동하는 반도체 공정 도구들을 펌프하기 위해 주로 사용되는 기술들을 살펴보고, 이 분야에서 진공을 만드는 기술적 방향에 대해 언급한다. 특히, Roots, Claw, Roots/claw 펌프의 작동원리와 자기 부양식 turbomolecular 펌프를 다루었다.

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