• Title/Summary/Keyword: Deposition temperature

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Chemical Beam Deposition of $MgF_2$ Thin Films (화학선 증착법에 의한 $MgF_2$ 박막제조)

  • 박보현;백성기
    • Journal of the Korean Ceramic Society
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    • v.33 no.3
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    • pp.299-306
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    • 1996
  • We invesgated the fesibility of thin films deposition by pyrolysis of metalorganic precursors using chemical beam deposition (CBD) process. We attempted to understand the effects of deposition variables such as substrate temperature operating pressure effusion cell temperature and H2 partial pressure on the properties of MgF2 grown by CBD. Mg(tfac)2 was used as a precursor. MgF2 thin films were always grown in an amorphous state and crystallized bypost-annealing. he higher the substrate temperature and the lower the operating pressure the less the impurities I the deposited MgF2 thin films. H2 gas has to be supplied for the pyrolitic reaction of Mg(tfac)2 decomposition. MgF2 films annealed in H2 have lower C impurity than those annealed in O2. But their crysatllinity was independent of annealing atmosphere. The optimum conditions for the prepara-tion of MgF2 films by CBD process were as following : The substrate temperature 55$0^{\circ}C$ the operating pressure 10-4 torr; effusion cell temperature 21$0^{\circ}C$ the percentage of H2 100% Post-annealing in H2 gas was required to remove residual carbon and to form MgF2 crystalline phase.

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A Study on the Effect of MgO Deposition Conditions and Ambient Temperature on the Firing Voltage and Discharge Characteristics of AC PDP (AC PDP의 MgO 증착조건과 고온하의 방전 안정성에 관한 연구)

  • Ryu, S.N.;Shin, M.K.;Kim, Y.K.;Heo, J.E.;Kim, D.H.;Lee, H.J.;Park, C.H.
    • Proceedings of the KIEE Conference
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    • 2002.07c
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    • pp.1644-1648
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    • 2002
  • The relationships between MgO deposition conditions and firing voltage of AC PDP were investigated as a function of ambient temperature. Substrate temperature and growth rate were selected as the major parameters that can affect the properties of MgO most significantly. Firing voltages increase with increasing temperature regardless of deposition conditions of the MgO layer. However, the relative magnitude of the firing voltage variation decrease with increasing substrate temperature and decreasing deposition speed. It was also found that the sample obtained at the condition of lower deposition rate shows better dynamic margin characteristics.

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Density and Corrosion Property Improvement of Zn-Mg Coatings by Controlling the Substrate Temperature during the Deposition (증착 기판 온도 제어에 따른 Zn-Mg 박막의 치밀도 및 내식성 향상에 관한 연구)

  • Song, Myeon-Kyu;La, Joung-Hyun;Kim, Hoe-Kun;Lee, Sang-Yul
    • Journal of the Korean institute of surface engineering
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    • v.50 no.4
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    • pp.266-271
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    • 2017
  • In this study, the corrosion resistance of Zn-3wt.%Mg coating was enhanced by controlling the density of coating. During the deposition the substrate temperature was controlled via an intermittent deposition process, resulting in the improvement of coating density. The maximum substrate temperature during this intermittent deposition process could be controlled from $200^{\circ}C$ to $80^{\circ}C$, depending upon the number of coating layer. The density of Zn-3 wt.%Mg coating increased from 76.1 % to 95.8 % as the substrate temperature was controlled. The salt spray test results revealed that the corrosion resistance of Zn-Mg coated steel could increase 3 times by increasing the density in coatings, while adhesion strength of coating was not changed significantly during 0-T bending test.

Low Pressure Chemical Vapor Deposition of Silicon Carbide (탄화규소의 저압 화학증착)

  • 송진수;김영욱;김동주;최두진;이준근
    • Journal of the Korean Ceramic Society
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    • v.31 no.3
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    • pp.257-264
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    • 1994
  • The objectives of this study were to develop the low pressure chemical vapor deposition(LPCVD) process of SiC and to fabricate pure and dense SiC layer onto graphite substrate at low temperature. The deposition experiments were performed using the MTS-H2 system (30 torr) in the deposition temperature ranging from 100$0^{\circ}C$ to 120$0^{\circ}C$. The deposition rate of SiC was increased with the temperature. The rate controlling step can be classified from calculated results of the apparent thermal activation energy as follows; surface reaction below 110$0^{\circ}C$ and gas phase diffusion through a stagnant layer over 110$0^{\circ}C$. The deposited layer was $\beta$-SiC with a preferred orientation of (111) and the strongly faceted SiC deposits were observed over 115$0^{\circ}C$.

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Numerical analysis of chromium deposition through the SOFC cathode channel (고체 산화물 연료전지의 공기극 유로내 크롬 피독에 관한 전산해석)

  • Park, Joon-Guen;Bae, Joong-Myeon;Lee, Shin-Ku;Nabielek, Heinz
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.11a
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    • pp.372-375
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    • 2006
  • SOFC is a high temperature fuelcell with many advantages, but it also have several demerits. One of the Issues is cathode poisoning of Cr coming from stainless steel interconnects. Diffusion process of Cr evaporated from the surface of interconnect steel was calculated by using CFD technique to understand factors for Cr deposition. It has been cleared that factors concerned in Cr deposition and how they affect Cr deposition. Major variables for Cr deposit ion are diffusion coefficient, air velocity and temperature If diffusion coefficient decreases, Cr concentration increases in the air but decreases on the cathode surface. Increasing in air velocity, Cr concentration decreases in the air and on the cathode surface. Increase in temperature leads to rising Cr concentration on the cathode surface because of diffusion coefficient increment.

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A study on the physical characteristics and conductivities of $\alpha$ -Sexithienyl thin films with various deposition conditions (성막조건에 따른 $\alpha$-Sexithienyl 박막의 물리적 특성 및 전기전도도에 관한 연구)

  • 박용인;권오관;오세운;최종선;김영관;신동명;강도열
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.04a
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    • pp.91-94
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    • 1997
  • $\alpha$-sexithienyl($\alpha$-6T) thin films were deposited by Organic Molecular Beam Deposition(OMBD) technique, where the $\alpha$-6T was synthesized and purified by the sublimation method. The thin films of the $\alpha$-6T were deposited under various deposition conditions. The effects of deposition rate, substrate temperature. and vacuum pressure an the formation of these films have been studied. The molecular orientations of $\alpha$-6T films were investigated with the polarized electronic absorption spectroscopy. The molecules in the $\alpha$-6T film deposited at a low deposition rate under a high vacuum were aligned almost perpendicular to the substrate. The film deposited at an elevated substrate temperature (~9 $O^{\circ}C$) showed higher conductivity than the film deposited at room temperature.

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Electrical and Optical Properties of $SnO_2$ Thin Films by Chemical Vapor Deposition (화학증착법에 의한 $SnO_2$ Film의 전기적 및 광학적 성질)

  • 김광호;김태옥;천성순
    • Journal of the Korean Ceramic Society
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    • v.23 no.5
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    • pp.81-85
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    • 1986
  • $SnO_2$ thin films have been prepared by chemical vapor deposition technique. Electrical and optical properties of the films have been investigated. It is found that the electrical condictivity and optical transparency of the films are most affected by deposition temperature and more affected by $SnCl_4$ partial pressure than by $O_2$ partial pressure. Experimental results show that the conductivity increases with high optical transparency as deposition temperature increases up to 50$0^{\circ}C$ but the conductivity decreases with the loss of transparency as deposition temperature increases above $600^{\circ}C$.

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The Effect of Deposition Temperature on the Growth behavior of TiN deposited by PECVD (TiN 박막 성장거동에 미치는 증착온도의 영향)

  • Lee, In Woo;Nam, O.H.;Kim, Moon Il
    • Journal of the Korean Society for Heat Treatment
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    • v.6 no.4
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    • pp.223-229
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    • 1993
  • Extensive reseach has been performed on the process condition-micro structure-stress relations of TiN film. The various proposed models are mainly base on physical vapor deposition processes. Especially the study on the micro-structure and deposition condition has not been sufficient in TiN deposited by PECVD. In this study, therefore, we discussed the morphological changes of TiN films by PECVD with different temperature and pressure, and compared it with the structure zone model. We could find out that the oxygen and chlorine contents and the texture coefficient increased with deposition temperature, and the morphology of TiN transformed from Zone 1 to Zone T, but deposition pressure didn't remarkly affected.

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Effect of Annealing Temperature on the Luminescence of Si Nanocrystallites Thin Films Prepared by Pulsed Laser Deposition (펄스 레이저 증착법으로 성장된 실리콘 박막의 어닐링 온도 변화에 따른 발광 특성연구)

  • 김종훈;전경아;이상렬
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.1
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    • pp.75-78
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    • 2002
  • Si thin films on p-type (100) Si substrate have been prepared by a pulsed laser deposition technique using a Nd:YAG laser. The pressure of the environmental gas during deposition was 1 Torr. After deposition, Si thin film has been annealed again at 400-840$^{\circ}C$ in nitrogen ambient. Strong blue photoluminescence (PL) have been observed at room temperature. We report the PL properties of Si thin films with the variation of the annealing temperature.

Simulation of the Particle Deposition on a Circular Cylinder in High-Temperature Particle-Laden Flow (원형 실린더 주위의 고온 유동에서 입자의 부착 해석)

  • Jeong, Seok-min;Kim, Dongjoo
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.18 no.2
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    • pp.73-81
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    • 2019
  • Numerical simulations are performed for the thermal fluid flow around a circular cylinder, and the particle trajectories are calculated to investigate the particle motions and deposition characteristics. We aim to understand the effects of three important parameters (particle Stokes number, temperature difference in the flow and on the cylinder surface, and thermal conductivity ratio between the fluid and the particles) on the deposition efficiency. The results show that the thermophorectic effect is insignificant for particles with large Stokes numbers, but it affects particles with small Stokes numbers. The deposition efficiency increases with the increase in temperature difference between the flow and the cylinder or the decrease in ratio of thermal conductivity of the particles to the fluid. When thermophoresis becomes significant, the particles are deposited even on the back side of the cylinder.