• 제목/요약/키워드: Buffer layer

검색결과 1,097건 처리시간 0.026초

Improvement of the Spin Transfer Induced Switching Effect by Copper and Ruthenium Buffer Layer

  • Nguyen T. Hoang Yen;Yi, Hyun-Jung;Joo, Sung-Jung;Jung, Myung-Hwa;Shin, Kyung-Ho
    • Journal of Magnetics
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    • 제10권2호
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    • pp.48-51
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    • 2005
  • The spin transfer induced magnetization switching has been reported to occur in magnetic multilayer structures whose scope usually consists of one stack of ferromagnetic / non-ferromagnetic / ferromagnetic (F / N / F) materials. In this work, it is shown that: 1) Copper used as a buffer layer between the free Co and the Au cap-layer can clearly increase the probability to get the spin transfer induced magnetization switching in a simple spin valve Co 11 / Cu 6/ Co 2 (nm); 2) Furthermore, when Ruthenium is simultaneously applied as a buffer layer on the Si-substrate, the critical switching currents can be reduced by $30\%$, and the absolute resistance change delta R $[{\Delta}R]$ of that stack can be enlarged by $35\%$. The enhancement of the spin transfer induced magnetization switching can be ascribed to a lower local stress in the thin Co layer caused by a better lattice match between Co and Cu and the smoothening effect of Ru on the thick Co layer.

Optoelectrical Properties of HgCdTe Epilayers Grown by Hot Wall Epitaxy

  • Yun, Suk-Jin;Hong, Kwang-Joon
    • 센서학회지
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    • 제13권4호
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    • pp.277-281
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    • 2004
  • $Hg_{1-x}Cd_{x}Te$ (MCT) was grown by hot wall epitaxy. Prior to the MCT growth, the CdTe (111) buffer layer was grown on the GaAs substrate at the temperature of $590^{\circ}C$ for 15 min. When the thickness of the CdTe buffer layer was $5{\mu}m$ or thicker, the full width at half maximum values obtained from the x-ray rocking curves were found to significantly decrease. After a good quality CdTe buffer layer was grown, the MCT epilayers were grown on the CdTe (111)/GaAs substrate at various temperatures in situ. The crystal quality for those epilayers was investigated by means of the x-ray rocking curves and the photocurrent experiment. The photoconductor characterization for the epilayers was also measured. The energy band gap of MCT was determined from the photocurrent measurement and the x composition rates from the temperature dependence of the energy band gap were turned out.

Effects of PEDOT:PSS Buffer Layer in a Device Structure of ITO/PEDOT:PSS/TPD/Alq3/Cathode

  • Ahn, Joon-Ho;Lee, Joon-Ung
    • Transactions on Electrical and Electronic Materials
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    • 제6권1호
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    • pp.25-28
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    • 2005
  • We have investigated the effects of hole-injection buffer layer in organic light-emitting diodes using poly(3,4-ethylenedioxythiophene):poly(stylenesulfonate)(PEDOT:PSS) in a device structure of $ITO/PEDOT:PSS/TPD/Alq_{3}/cathode$. Polymer PEDOT:PSS buffer layer was made by spin casting method. Current-voltage, luminance-voltage characteristics and efficiency of device were measured at room temperature with a variation of cathode materials; Al, LiF/Al, LiAl, and Ca/Al. The device with LiF/Al cathode shows an improvement of external quantum efficiency approximately by a factor of ten compared to that of Al cathode only device. Our observation shows that cathode is important in improving the efficiency of the organic light-emitting diodes.

$TaN/Al_{2}O_{3}$ 박막 저항소자 개발에 관한 연구 (A study on TCR characteristic of $TaN/Al_{2}O_{3}$ thin film resistors)

  • 김인성;조영란;민복기;송재성
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 춘계학술대회 논문집 센서 박막재료 반도체재료 기술교육
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    • pp.82-85
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    • 2002
  • In recent years, the tantalum nitride(TaN) thin-film has been developed for the electronic resistor and capacitor. In this papers, this study presents the surface profile and sheet-resistance property relationship of reactive-sputtered TaN thin film resistor processed by buffer of Ti and Cr on alumina substrate. The TCR properties of the TaN films were discussed in terms of reactive gas ratio, ratio of nitrogen, crystallization and thin films surface morphology due to annealing temperature. It is clear that the TaN thin-films resistor electrical properties are low TCR related with it's buffer layer condition. Ti buffer layer thin film resistor having a good thermal stability and lower TCR properties then Cr buffer expected for the application to the dielectric material of passive component.

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토양의 산/염기 완충능의 모델링 (Modeling of Acid/Base Buffer Capacity of soils)

  • 김건하
    • 한국토양환경학회지
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    • 제3권3호
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    • pp.3-10
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    • 1998
  • 토양의 산/염기 완충능은 토양-오염물질-공극수로 이루어진 시스템의 pH에 직접적인 영향을 미치므로 오염물질의 토양내 거동예측시에 많은 영향을 미치는 매우 중요한 토양의 성질이다. 본 연구는 이중확산층이론과 two layer electrostatic 흡착모델을 응용하여 토양의 산/염기 완충능의 이론모델을 유도하고 이 모델의 적용절차를 제시하였다. 산-염기 적정실험을 통하여 두 종류의 카올리나이트의 완충능을 실측하고 이를 본 연구에서 개발된 모델의 예측치와 비교하였다.

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RF 스퍼터링으로 Si 기판위에 제작된 ZnO 박막에서 ZnO 버퍼층의 가스분위기 영향 (Effects of the Gas Atmosphere of ZnO Buffer Layers in the ZnO films grown on Si Substrates by RF Magnetron Sputtering)

  • 박태은;조형균;공보현;홍순구
    • 한국전기전자재료학회논문지
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    • 제18권7호
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    • pp.656-661
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    • 2005
  • The effects of gas atmosphere and in-situ thermal annealing in buffet layers on the characteristic of the ZnO grown by RF magnetron sputtering have been investigated. It was shown that the introduction of buffer layers grown at the gas atmospheres of the mixed $Ar/O_2$ and the in-situ thermal treatment of the ZnO buffer layer improved the structural and optical properties. In addition, the ZnO films on the buffer layer thermal-annealed at $N_2$ gas ambience showed the strong emission of the near band gap exciton with narrow linewidth by combining the high-temperature growth of the ZnO film.

GaN-on-Si 기술을 위한 탄화텅스텐 버퍼층의 성장에 관한 연구 (Investigation on the Growth of Tungsten Carbide Layer as a Buffer for GaN-on-Si Technology)

  • 조성민;최정훈;최성국;조영지;이석환;장지호
    • 한국전기전자재료학회논문지
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    • 제30권1호
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    • pp.1-6
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    • 2017
  • Tungsten carbide (WC) has been suggested as a new buffer layer for the GaN-on-Si technology. We have investigated and optimized the sputtering condition of WC layer on the Si-substrate. We confirmed the suppression of the Si melt-back phenomenon. In addition, surface energy of WC/Si layer was measured to confirm the possibility as a buffer layer for GaN growth. We found that the surface energy(${\gamma}=82.46mJ/cm^2$) of WC layer is very similar to that of sapphire substrate(${\gamma}=82.71mJ/cm^2$). We grow GaN layer on the WC buffer by using gas-source MBE, and confirm that it is available to grow a single crystalline GaN layer.