• Title/Summary/Keyword: Vacuum condition

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Quantum Confimement Effect in $SiO_2$ Thin Films Embedded with Semiconductor Microcrystallites

  • Wu-Xuemei;Chen-Jing;Ahuge-Lanjian
    • Journal of the Korean Vacuum Society
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    • v.7 no.s1
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    • pp.25-29
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    • 1998
  • $SiO_2$ thin films embedded with Ge microcrystallites (Ge-$SiO_2$) were prepared by use of r.f. co-sputtering technique from a Ge, $SiO_2$ composite target. The size of Ge crystallites can been modulated by the experiment parameters. The optical absorption and non-linear optical properties of Ge-$SiO_2$ films were measured. The blue shift of the optical absorption edge, the saturated absorption and two-photon absorption under the condition of resonant absorption have been observed, and are discussed according to the quantum confinement effect.

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Efficiency Analysis of Knudsen Pump According to Hanji Membrane (한지 멤브레인을 사용한 누센펌프의 효율 분석)

  • Yun, Dong-Ik;Huh, Hwan-Il
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2010.11a
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    • pp.618-619
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    • 2010
  • Thermal transpiration device(Knudsen pump) having no moving parts can self-pump the gaseous propellant by temperature gradient only (cold to hot). We designed, fabricated the Knudsen pump and analyzed pressure gradient efficiency of membrane according to Knudsen number under vacuum condition. In this paper, we measured presented pumping efficiency of Knudsen pump according to Hanji membrane.

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Deposition Technology of Copper Thin Films for Multi-level Metallizations (다층배선을 위한 구리박막 형성기술)

  • 조남인;정경화
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • 2002.05a
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    • pp.180-182
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    • 2002
  • Copper thin films are prepared by a chemical vapor deposition technology for multi-level metallzations in ULSI fabrication. The copper films were deposited on TiN/Si substrates in helium atmosphere with the substrate temperature between $120^{\circ}C$ and $300^{\circ}C$. In order to get more reliable metallizations, effects on the post-annealing treatment to the electrical properties of the copper films have been investigated. The Cu films were annealed at the $5\times$10^{-6}$ Torr vacuum condition, and the electrical resistivity and the nano-structures were measured for the Cu films. The electrical resistivity of Cu films shown to be reduced by the post-annealing. The electrical resistivity of 2.2 $\mu$$\Omega$.cm was obtained for the sample deposited at the substrate temperature of $180^{\circ}C$ after vacuum annealed at $300^{\circ}C$. The resistivity variations of the films was not exactly matched with the size of the nato-structures of the copper grains, but more depended on the deposition temperature of the copper films.

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Relationship between Optical Properties Analyzed by Photoluminance of Bonding Structure Analyzed by X-ray Diffractometer (XRD 분석에 의한 결정구조와 PL 분석에 의한 광학적 특성의 상관성)

  • Oh, Teresa
    • Journal of the Semiconductor & Display Technology
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    • v.15 no.1
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    • pp.70-75
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    • 2016
  • GZO films prepared on ITO glasses were annealed at various temperatures in a vacuum condition to research the relationship between oxygen vacancies and optical properties. GZO films after annealing in a vacuum showed the various optical-chemical properties depending on the annealing temperatures and oxygen gas flow rate during the deposition. The oxygen vacancy of GZO film prepared by oxygen gas flows of 22 sccm increased with increasing the annealing temperatures, because of the extraction of oxygen by the annealing. But the intensity of photoluminance of GZO with 22 sccm decreased in accordance with the annealing temperature, because of the reduction of ionized charge carriers. The oxygen vacancy by the extraction of oxygen enhanced a depletion, so the widen depletion had the strong Schottky barrier and the PL intensity due to the low carrier density decreased.

The Stream and Exhaust Gas Characteristics for Variation of Exhaust Gas Temperature of Marine Incinerator Ejector (선박용 소각로 이젝터의 배출온도 변화에 따른 유동과 배기특성)

  • 김태한
    • Journal of Ocean Engineering and Technology
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    • v.14 no.2
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    • pp.60-64
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    • 2000
  • An experimental study was performed to investigate the optimal ejector and operating condition of vessel incinerator. Exhaust gas temperature and secondary air which makes vacuum pressure at ejector throat regions were considered as an important factor. According to the measurement of pressure temperature and nitrogen oxides between non combustion and combustion we found the stream and exhaust gas characteristics of incinerator. This results can give us the exhaust gas temperature control system air pollutant reduction method and the optimum ejector design.

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Surface properties of epoxy/glass Eber composites by environmental conditions (사용 환경조건에 따른 Epoxy/Glass Fiber 복합재료의 표면특성)

  • 임경범;이백수;황명환;김윤선;유도현;이덕출
    • Journal of the Korean Vacuum Society
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    • v.9 no.3
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    • pp.279-284
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    • 2000
  • In order to analysis the degradation process of epoxy/glass fiber for outdoor condition, FRP laminate was exposed to high temperature and water. Then the degradation process was evaluated by comparing contact angle, surface potential decay, and surface resistivity. For the change of wettability, the contact angle of thermal-treated specimen with the high temperature of $200^{\circ}C$ increased. But that of water-treated specimen decreased. The characteristic of surface potential decay shows the tendency of the remarkable decrease on water-treated specimens, but increase on thermal-treated specimen compared with untreated one. Also, for the surface resistivity, it shows the same trend compared with the change of contact angle.

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Effects of RF pulsing and axial magnetic field onionized magnetron sputtering

  • Joo. Junghoon
    • Journal of Korean Vacuum Science & Technology
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    • v.2 no.2
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    • pp.133-138
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    • 1998
  • To enhance the ionization level of I-PVD and reduce the coil voltage two approaches were tried and as a diagnostic, optical emission spectroscopy and impedance analysis of the plasma was done with a range of Ar pressures and RF power along with XRD analysis of deposited Ag films. RF sputtering power was pulsed with various on/off time scales to recover the ICP quenched by sputtered metals. This in average enhances the ionization of the sputtered atoms with 10 ms/10 ms and 100 ms/100ms pulse on/off time duration and gives higher (200) preferred orientation over (111) in deposited Ag films. Secondly, Small axial B field about 8G remarkably reduced RF coil sputtering and showed scaled relationship between RF power and magnetic field strength for optimal process condition. From OES of Ar0 and Ar+, wave-like dispersion structure appeared and reduced the coil voltage about 20% at very weak field strength of 8G. This should be studied further to have nay relation with low mode helicon wave launching.

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Interface Characteristics of Ion Beam Mixed Cu/polyimide system

  • G.S.Chang;Jung, S.M.;Lee, Y.S.;Park, I.S.;Kang, H.J.;J.J.Woo;C.N.Whang
    • Journal of the Korean Vacuum Society
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    • v.4 no.S2
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    • pp.1-7
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    • 1995
  • Cu(400$\AA$)/Polyimide has been mixed with 80 keV Ar+ and N2+from 1.0X1015ions/$\textrm{cm}^2$ to 2.0X1016 ions/$\textrm{cm}^2$. The changes of chemical bond and internal properties of sample are investigated by X-ray photoelectron spectroscopy(XPS). The quantitative adhesion strength is measured by using scratch test. The optimized mixing condition is that Cu/PI is irradiated with 80 keV N2+ at a dose of 1.0X1015 ions/$\textrm{cm}^2$, because N2+ ions can product more pyridine-like moiety, amide group, and tertiary amine moiety which are known as adesion promoters than Ar+.

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Effect of rapid thermal annealing on CdS films prepared by RF magnetron sputtering

  • Hwang, Dong-Hyeon;Gam, Dae-Ung;An, Jeong-Hun;Son, Yeong-Guk
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.164-164
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    • 2010
  • Cds films were deposited on glass substrates using rf magnetron sputtering method followed by rapid thermal annealing(RTA). Effects of annealing temperature on surface characteristic, structural, electrical and optical property of CdS films were investigated at different temperatures ranging from 250 to $550^{\circ}C$ with various holding time. The film annealed at $450^{\circ}C$ with less than 1 min holding time is attributed to the improved crystalline quality of CdS film due to the effective relaxation of residual compressive stress and achieving maximum grain size. The results show that RTA treatments under optimal annealing condition can provide significant improvements in the properties of CdS films.

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Characterization of In-Situ Film Thickness and Chamber Condition of Low-K PECVD Process with Impedance Analysis

  • Kim, Dae Kyoung;Jang, Hae-Gyu;Kim, Yong-Tae;Kim, Hoon-Bae;Chae, Hee-Yeop
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.461-461
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    • 2010
  • For a low dielectric constant inter-metal dielectric application, the low-k SiCOH film with a dielectric constant of 2.8-3.2 has been deposited by plasma-enhanced chemical vapor deposition with decamethylcyclopentasiloxane, cyclohexane, and helium which is carrier gas. In this work, we investigated chemical deposition rate, dielectric constant, characterization of plasma polymer films according to temperature(25C-200C) of substrate and change of component concentration. We measured impedance by using V-I prove during process. From experimental result, deposition rate decrease with increasing temperature. Through real time impedance analysis of chamber, we find corelation between film thickness and impedance by assuming equivalent circuit.

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