• 제목/요약/키워드: $O_2$ partial pressure

검색결과 488건 처리시간 0.025초

Zinc acetate를 precursor로 한 고저항 ZnO막의 제조 및 습도감지 특성 (Fabrication of High-resistive ZnO Films Using Zinc acetate as Precursor and Their Humidity-sensing Properties)

  • 마대영;김상현;김영일
    • 센서학회지
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    • 제5권1호
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    • pp.37-42
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    • 1996
  • 기존의 진공증착 방법으로 $SiO_{2}$ 막이 성장된 Si웨이퍼 위에 ZnO막을 제조하였다. Anhydrous zinc acetate를 자체 제작한 황동보트안에 넣고 가열하여 승화시켰다. 기판온도는 $200^{\circ}C$에서 $600^{\circ}C$까지 변화시켰으며 공정중에 산소를 주입하여 챔버내 산소 분압을 증가시켰다. 증가된 산소분압에 의해 고저항의 ZnO막을 얻을 수 있었다. 제조된 막의 결정성 및 성분을 알기 위해 XRD, EDS 및 RBS 측정을 하였다. 고저항의 ZnO막은 70%이상의 상대습도에 매우 민감한 저항감소를 나타내었다.

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Modeling of Electrical Conductivity from $\sigma$tot vs. Po21/4 Plot in Wet Atmosphere for High-Temperature Proton-Conducting Oxides

  • Baek, Hyun-Deok
    • The Korean Journal of Ceramics
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    • 제4권2호
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    • pp.136-140
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    • 1998
  • This work demonstrates a method for modeling of electrical conductivity in high-temperature proton-conducting oxides. Total conductivity was calculated assuming that it comprises partial conductivities contributed by protons, oxygen ions and electron holes. From the polt $\sigma_{tot}$ vs. $po_2\;{1/4}$ in wet atmosphere, thermodynamic and kinetic parameters were obtained representing transport properties such as concentration and mobility of the charge-carrying defects. The formulas for the calculation of partial conduction were derived based on the defect structure of HTPCs. Illustrative calculation were made for $SrCe_{0.95}Yb_{0.05}O_{2.975}$ system.

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반응성 r.f. 스퍼터링에 의한 마이크로 박막 전지용 산화바나듐 박막의 제작 및 전기화학적 특성 평가 (Fabrication and electrochemical characterization of amorphous vanadium oxide thin films for thin film micro-battery by reactive r.f. sputtering)

  • 전은정;신영화;남상철;윤영수;조원일
    • 한국진공학회지
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    • 제9권1호
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    • pp.42-47
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    • 2000
  • The amorphous vanadium oxide thin films for thin-film rechargeable lithium batteries were fabricated by r.f. reactive sputtering at room temperature. As the experimental parameter, oxygen partial pressure was varied during sputtering. At high oxygen partial pressures(>30%), the as-deposited films, constant current charge/discharge characteristics were carried out in 1M $LiPF_6$, EC:DMC+1:1 liquid electrolyte using lithium metal as anode. The specific capacity of amorphous $V_2O_5$ after 200cycles of operation at room temperature was higher compared to crystalline $V_2O_5$. The amorphous vanadium oxide thin film and crystalline film showed about 60$\mu$Ah/$\textrm{cm}^2\mu\textrm{m}$ and about 38$\mu$Ah/$\textrm{cm}^2\mu\textrm{m}$, respectively. These results suggest that the battery capacity of the thin film vanadium oxide cathode strongly depends on the crystallinity.

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코딩-열분해법에 의해 제조한 BaTiO$_3 $ 박막의 결정 성장을 위한 낮은 산소 분압에서의 열처리 (Annealing under low oxygen partial pressure for crystal growth of BaTiO$_3 $thin films prepared by coating-pyrolysis process)

  • 김승원
    • 한국결정성장학회지
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    • 제10권2호
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    • pp.111-115
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    • 2000
  • Ba과 Ti의 금속 유기 화합물을 이용하여 (100) $SrTiO_3$ 기판 위에 $BaTIO_3$ 박막을 코팅-열분해법으로 제조하였다. $450^{\circ}C$에서 사전 열처리한 비정질상의 박막은 $2\times 10^{-4}$ atm으로 조정된 산소 분압 하에서 $700^{\circ}C$ 이상의 온도로 열처리함으로써 결정화되었다. $800^{\circ}C$ 이하에서 제조한 박막의 기판에 수직한 면의 격자상수는 cubic $BaTIO_3$의 a 값에 가까우면 $800^{\circ}C$ 이하에서 제조한 박막의 tetragonal $BaTIO_3$ 의 a 값에 가까 웠다. 박막과 기판의 정렬상태를 XRD $\beta$ scan과 pole-figure로 분석한 결과 $BaTIO_3$ 박막은 $SrTiO_3$ 기판과 에피택시 관계가 있었다. $800^{\circ}C$에서 열처리한 박막의 표면은 0.4${\mu}m$ 정도의 섬 형태의 입자로 구성되어 있었고 약 0.8$\mu\textrm{m}$의 두께를 가진 단면은 구형의 입자가 층을 이루고 있었다.

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The Effect of CVD Reaction Variable on SnO2 Powder Characteristics

  • Kim, Kyoo-Ho
    • The Korean Journal of Ceramics
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    • 제4권3호
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    • pp.235-239
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    • 1998
  • Ultrafine $SnO_2$ powder was prepared by the diffusion mixing gas-phase reaction of $SnCl_4$(g) and water vapor. The effects of reaction variables, such as the chloride partial pressure, the reaction temperature, and the residence time is the reactor, on the powder size were examined systematically. Calculated concentration and distribution of chemical species, using the Burke-Schumann diffusion mixing model, were compared with the experimetal results. The effects of the reaction variables on the powder size were also discussed qualitatively.

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Phase Stability and Electronic Properties of $Bi_2BaLnCuO_{6+δ}$ Cuprates with Structure 2201 Type

  • V. E. Fedorov;N. G. Naumov;P. P. Samoilov;N. F. Zakharchuk;N. I. Matskevich;백우현
    • Bulletin of the Korean Chemical Society
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    • 제16권6호
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    • pp.484-489
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    • 1995
  • The synthesis of new bismuth-barium containing members of layered cuprates with 2201 type structure was reported. By solution calorimetry the formation enthalpies for Bi2MLaCuO6.5 (M=Ba, Ba0.5Sr0.5, Sr) were obtained. Crucial influence of partial oxygen pressure and size of lanthanoid on stability of layered cuprates was shown. Electronic states of variable valence atoms were studied by voltammetry of solids.

이온선 스퍼터 증착법에 의하여 제초된 CrOX의 전기적 특성에 관한 연구 (Study on The Electrical Characteristics of Chromium Oxide Film Produced by ton Beam Sputter Deposition)

  • 조남제;장문식;이규용
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1999년도 추계학술대회 논문집
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    • pp.409-414
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    • 1999
  • The influence of ion beam energy and reactive oxygen partial pressure on the electrical and crystallographic characteristics of transition metal oxide compound(Cr0x) film was studied in this paper. Chromium oxide films were prepared onto the coverglass using Ion Beam Sputter Deposition(1BSD) technique according to the processing conditions of the partial pressure of reactive oxygen gas and ion beam energy. Crystallinity and grain size of as-deposited films were analyzed using XRD analysis. Thickness and Resistivity of the films were measured by $\alpha$-step and 4-point probe measurement. As results, according to the XRD, XPS and resistivity measurement, the deposited films were the cermet type films which has a crystal structure including amorphous oxide(a-oxide) phase and metal Cr phase simultaneously. The increasernent of the ion b m energy during the deposition process happened to decreasernent of metal Cr grain size and the rapid change of resistivity above the critical $O_2$ partial pressure.

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양축 정렬된 Ni기판 위에 MOCVD법에 의한 YBCO 초전도 선재용 Ce$O_{2}$ 완충층의 증착 (Deposition of Ce$O_{2}$ buffer layer for YBCO coated conductors on hi-axially textured Ni substrate by MOCVD technique)

  • 김호진;주진호;전병혁;정충환;박순동;박해웅;홍계원;김찬중
    • 한국초전도저온공학회:학술대회논문집
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    • 한국초전도저온공학회 2002년도 학술대회 논문집
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    • pp.91-94
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    • 2002
  • Textured Ce$O_{2}$ buffers for YBCO coated conductors were deposited on biaxially textured Ni substrate by metalorganic chemical vapor deposition The texture of deposited Ce$O_{2}$ films was varied with deposition temperature(T) and oxygen partial pressure($Po_{2}$). ($\ell$ 00) textured Ce$O_{2}$ films were deposited at T= 500~$520^{\circ}C$, $Po_{2}$= 0.90~3.33 Torr. The growth rate of the Ce$O_{2}$ films was 150~200 nm/min at T= $520^{\circ}C$ and $Po_{2}$= 2.30 Torr, which was much faster than that prepated by other physical deposition method.

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스퍼터된 바나듐 산화막의 구조적 특성에 미치는 진공 어닐링의 효과 (Effects of Vacuum Annealing on the Structural Properties of Sputtered Vanadium Oxide Thin Films)

  • 황인수;최복길;최창규;권광호;김성진
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 춘계학술대회 논문집 센서 박막재료 반도체재료 기술교육
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    • pp.70-73
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    • 2002
  • Thin films of vanadium oxide($VO_{x}$) have been deposited by r.f. magnetron sputtering from $V_{2}O_{5}$ target in gas mixture of argon and oxygen. The oxygen/(oxygen+argon) partial pressure ratio of 0% and 8% is adopted. Crystal structure, chemical composition, molecular structure and optical properties of films sputter-deposited under different oxygen gas pressures and in-situ annealed in vacuum at $400^{\circ}C$ for 1h and 4h are characterized through XRD. RBS, FTlR and optical absorption measurements. The films as-deposited are amorphous and those annealed for time longer than 4h are polycrystalline. $V_{2}O_{5}$ and lower oxides co-exist in sputter-deposited films and as the oxygen partial pressure is increased the films become more stoichiometric $V_{2}O_{5}$. When annealed at $400^{\circ}C$, the as-deposited films are reduced to a lower oxide. It is observed that the oxygen atoms located on the V-O plane of $V_{2}O_{5}$ layer participate more readily in the oxidation and reduction process. The optical transmission of the films annealed in vacuum decreases considerably than the as-deposited films and the optical absorption of all the films increases rapidly between 400 and 550nm.

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마그네트론 스퍼터링에 의해 성장된 ZnO 박막의 산소 분압 의존성 (Dependency of oxygen partial pressure on the characteristics of ZnO films grown by magnetron sputtering)

  • 안철현;김영이;강시우;공보현;조형균
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2007년도 춘계학술발표회 초록집
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    • pp.67-68
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    • 2007
  • 마그네트론 스퍼터링을 이용하여 사파이어 기판위에 $O_2$의 분압에 따른 성장된 ZnO박막의 특성에 대해 연구하였다. $O_2$의 분압은 $Ar/O_2$의 비율에 의해 조절을 하여 성장을 하였으며, $O_2$의 분압이 감소함에 따라 결정성이 좋아지는 결과를 얻었다. PL측정결과에서 순수한 Ar분위기에서 성장된 ZnO박막에서 UV 발광과 더불어 Deep 1evel에 기인하는 Green 발광을 보였고, UN-Visible spectroscopy 측정결과 순수한 Ar분위기를 제외한 샘플에서 $60{\sim}80%$의 투과도를 보였다. SEM과 TEM의 이미지를 통해 미세 힐락들을 관찰되었는데, 이로 인해 투과도의 저하 원인으로 분석된다.

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