• Title/Summary/Keyword: vacuum ultraviolet

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Development of the Most Optimized Ionizer for Reduction in the Atmospheric Pressure and Inert Gas Area (감압대기 및 불활성가스 분위기에서 적합한 정전기 제거장치의 개발)

  • Lee, Dong Hoon;Jeong, Phil Hoon;Lee, Su Hwan;Kim, Sanghyo
    • Journal of the Korean Society of Safety
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    • v.31 no.3
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    • pp.42-46
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    • 2016
  • In LCD Display or semiconductor manufacturing processes, the anti-static technology of glass substrates and wafers becomes one of the most difficult issues which influence the yield of the semiconductor manufacturing. In order to overcome the problems of wafer surface contamination various issues such as ionization in decompressed vacuum and inactive gas(i.e. $N_2$ gas, Ar gas, etc.) environment should be considered. Soft X ray radiation is adequate in air and $O_2$ gas at atmospheric pressure while UV radiation is effective in $N_2$ gas Ar gas and at reduced pressure. At this point of view, the "vacuum ultraviolet ray ionization" is one of the most suitable methods for static elimination. The vacuum ultraviolet can be categorized according to a short wavelength whose value is from 100nm to 200nm. this is also called as an Extreme Ultraviolet. Most of these vacuum ultraviolet is absorbed in various substances including the air in the atmosphere. It is absorbed substances become to transit or expose the electrons, then the ionization is initially activated. In this study, static eliminator based on the vacuum ultraviolet ray under the above mentioned environment was tested and the results show how the ionization performance based on vacuum ultraviolet ray can be optimized. These vacuum ultraviolet ray performs better in extreme atmosphere than an ordinary atmospheric environment. Neutralization capability, therefore, shows its maximum value at $10^{-1}{\sim}10^{-3}$ Torr pressure level, and than starts degrading as pressure is gradually reduced. Neutralization capability at this peak point is higher than that at reduced pressure about $10^4$ times on the atmospheric pressure and by about $10^3$ times on the inactive gas. The introductions of these technology make it possible to perfectly overcome problems caused by static electricity and to manufacture ULSI devices and LCD with high reliability.

Fabrication of reflectometer for vacuum ultraviolet spectral characteristic measurements of optical component (광학부품의 진공자외선특성 측정용 분광반사율계 제작)

  • 신동주;김현종;이인원
    • Korean Journal of Optics and Photonics
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    • v.15 no.4
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    • pp.325-330
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    • 2004
  • We fabricated a vacuum ultraviolet spectre-reflectometer which consists of a deuterium light source, a vacuum monochromator, and a sample chamber and detector module. The operation was performed in the ultraviolet spectral ranges between 115 nm and 330 nm at the vacuum pressure of 3.0 ${\times}$ 10$^{-4}$ Pa. The wavelength of the vacuum monochromator was calibrated with the line spectrum of a low pressure Mercury lamp of 253.652 nm and 184.95 nm wavelengths, and its resolution was 0.012 nm, and the precision of wavelength was $\pm$ 0.03 nm. With this reflectometer and a deuterium lamp, we measured the spectral regular transmittance and reflectance of materials(MgF$_2$, CaF$_2$, BaF$_2$, SiO$_2$, Sapphire) used as optical components over the spectral range between 115 nm and 230 nm.

Photoluminescence Characteristics of Eu-doped YBO3 Phosphor Prepared by Spray Pyrolysis under Vacuum Ultraviolet (분무열분해 공정에 의해 합성된 유로피움이 도핑된 YBO3 형광체의 진공자외선 하에서의 발광 특성)

  • Koo, Hye-Young;Kang, Yun-Chan
    • Korean Journal of Materials Research
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    • v.16 no.8
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    • pp.485-489
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    • 2006
  • The preparation conditions of $YBO_3$:Eu phosphor particles having the maximum photoluminescence intensity under vacuum ultraviolet in the spray pyrolysis were optimized. The $YBO_3$:Eu phosphor particles prepared from spray solution with stoichiometric amount of boric acid had the maximum photoluminescence intensity. The $YBO_3$:Eu phosphor particles with pure phases were formed at low post-treatment temperatures because of fast reaction of yttrium and boron components without volatilization of boron component. The prepared $YBO_3$:Eu phosphor particles by spray pyrolysis had fine size, narrow size distribution and regular morphology. The photoluminescence intensity of the prepared $YBO_3$:Eu phosphor particles under vacuum ultraviolet was 103% of the commercial $(Y,Gd)BO_3$:Eu phosphor particles.

Ultraviolet-emissive BaSiO3:Ce3+ Phosphor for VUV Excimer Lamp

  • Lee, Jugyeong;Afandi, Mohammad M.;Kim, Jongsu;Heo, Hoon
    • Journal of the Semiconductor & Display Technology
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    • v.20 no.2
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    • pp.1-5
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    • 2021
  • Ultraviolet (UVA)-emissive BaSiO3:Ce3+ phosphor was astonishingly reproducible by vacuum-sintering at a high temperature through a simple solid-state reaction method. It was conveniently formed in BaSiO3 phases. The compound showed the UVA emission and the UV-VUV excitation due to 5d-4f transitions from Ce3+ ions: emission peak at 380 nm with a 56 nm width. Its temperature dependence and vacuum UV excitability were examined for practical application as an excimer discharge lamp, which showed the high thermal stability (80% at 100℃) and the strong VUV excitations at 145 nm and 172 nm.