• 제목/요약/키워드: bias dependence

검색결과 194건 처리시간 0.025초

Relationship between Magnetic Properties of YIG Ferrites and Intermodulation Characteristics of Microwave Isolators

  • Nukaga, Masako;Henmi, Sakae
    • The Korean Journal of Ceramics
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    • 제6권3호
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    • pp.300-303
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    • 2000
  • The generation of the intermodulation noises in microwave isolators has been studied in relation to the characteristics of YIG ferrites designed for this application. We have investigated the influences of porosity and crystalline anisotropy related to the magnetic loss, which causes the generation of intermodulation signals. The power dependence of the intermodulation power level is stressed as the crystalline anisotropy decreases. These results are consistent with the nonlinear effects of a single normal mode before the excitation of the spin-waves. It also appears that this power level is proportional to the magnitude of dc bias magnetic field.

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자기인지 신경회로망에서 아날로그 기억소자의 선형 시냅스 트랜지스터에 관한연구 (A Study on the Linearity Synapse Transistor of Analog Memory Devices in Self Learning Neural Network Integrated Circuits)

  • 강창수
    • E2M - 전기 전자와 첨단 소재
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    • 제10권8호
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    • pp.783-793
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    • 1997
  • A VLSI implementation of a self-learning neural network integrated circuits using a linearity synapse transistor is investigated. The thickness dependence of oxide current density stress current transient current and channel current has been measured in oxides with thicknesses between 41 and 112 $\AA$, which have the channel width $\times$ length 10 $\times$1${\mu}{\textrm}{m}$, 10 $\times$ 0.3${\mu}{\textrm}{m}$ respectively. The transient current will affect data retention in synapse transistors and the stress current is used to estimate to fundamental limitations on oxide thicknesses. The synapse transistor has represented the neural states and the manipulation which gaves unipolar weights. The weight value of synapse transistor was caused by the bias conditions. Excitatory state and inhitory state according to weighted values affected the drain source current.

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Frequency Dependency of Multi-layer OLED Current Density-voltage Shift and Its Application to Digitally-driven AMOLED

  • Kim, Hyunjong;Kim, Suhwan;Hong, Yongtaek
    • Journal of the Optical Society of Korea
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    • 제16권2호
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    • pp.181-184
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    • 2012
  • We report, for the first time, operation frequency dependence of current density-voltage ($J_{OLED}-V_{OLED}$) shift for multi-layer organic light-emitting diodes (OLEDs). When the OLEDs were electrically stressed for 21 hours with 50% duty voltage pulses at 60, 120, 240, and 360 Hz, the JOLED-VOLED shifts were suppressed by half for 360 Hz operation compared with 60 Hz operation, but with little change in emission efficiencies. This frequency dependent $J_{OLED}-V_{OLED}$ shift is believed to be commonly observed for typical multi-layer OLEDs and can be used to further improve lifetime of digitally-driven active-matrix OLED displays.

Recent Development of MRAM Technology

  • Miyazaki, T.;Ando, Y.;Kubota, H.
    • Journal of Magnetics
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    • 제8권1호
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    • pp.36-44
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    • 2003
  • Three topics which are related to technologies for developing of large capacity MRAM over Gbits are reviewed. First, it is stressed that inelastic-electron-tunnel-tunneling spectroscopy(IETS) is a powerfull method to investigate the interface state between magnetic electrodes and insulator. Second, magnetic tunnel junctions with small bias voltage dependence are introduced. Finally, fabrication method of carbon masks for very small magnetic tunnel junctions is demonstrated. These three topics were presented at 47^{th} MMM 2002 conference and each paper will appear in the proceedings.

저온 제작 다결정 실리콘 박막 트랜지스터의 off-current메카니즘에 관한 연구 (A study on the off-current mechanism of poly-Si thin film transistors fabricated at low temperature)

  • 진교원;김진;이진민;김동진;조봉희;김영호
    • E2M - 전기 전자와 첨단 소재
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    • 제9권10호
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    • pp.1001-1007
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    • 1996
  • The conduction mechanisms of the off-current in low temperature (.leq. >$600^{\circ}C$) processed polycrystalline silicon thin film transistors (LTP poly-Si TFT'S) have been systematically studied. Especially, the temperature and bias dependence of the off-current between hydrogenated and nonhydrogenated poly-Si TFT's were investigated and compared. The off-current of nonhydrogenated poly-Si TF's is because of a resistive current at low gate and drain voltage, thermally activated current at high gate and low drain voltage, and Poole-Frenkel emission current in the depletion region near the drain at high gate and drain voltage. After hydrogenation it has shown that the off -current mechanism is caused mainly by thermal activation and that the field-induced current component is suppressed.

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Characteristics of Trap in the Thin Silicon Oxides with Nano Structure

  • Kang, C.S.
    • Transactions on Electrical and Electronic Materials
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    • 제4권6호
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    • pp.32-37
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    • 2003
  • In this paper, the trap characteristics of thin silicon oxides is investigated in the ULSI implementation with nano structure transistors. The stress and transient currents associated with the on and off time of applied voltage were used to measure the distribution of high voltage stress induced traps in thin silicon oxide films. The stress and transient currents were due to the charging and discharging of traps generated by high stress voltage in the silicon oxides. The transient current was caused by the tunnel charging and discharging of the stress generated traps nearby two interfaces. The stress induced leakage current will affect data retention in electrically erasable programmable read only memories. The oxide current for the thickness dependence of stress current, transient current, and stress induced leakage currents has been measured in oxides with thicknesses between 113.4nm and 814nm, which have the gate area 10$\^$-3/ $\textrm{cm}^2$. The stress induced leakage currents will affect data retention, and the stress current and transient current is used to estimate to fundamental limitations on oxide thicknesses.

자기인지 신경회로망에서 선형 시냅스 트랜지스터에 관한 연구 (A Study on the Linearity Synapse Transistor in Self Learning Neural Network)

  • 강창수;김동진;김영호
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 하계학술대회 논문집
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    • pp.59-62
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    • 2000
  • A VLSI implementation of a self-learning neural network integrated circuits using a linearity synapse transistor is investigated. The thickness dependence of oxide current density, stress current, transient current and channel current has been measured in oxides with thicknesses between 41 and 112 $\AA$, which have the channel width$\times$length 10$\times$1${\mu}{\textrm}{m}$ respectively. The transient current will affect data retention in synapse transistors and the stress current is used to estimate to fundamental limitations on oxide thicknesses. The synapse transistor has represented the neural states and the manipulation which gave unipolar weights. The weight value of synapse transistor was caused by the bias conditions. Excitatory state and inhitory state according to weighted values affected the drain source current.

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The Trap Characteristics of SILC in Silicon Oxide for SoC

  • Kang C. S.
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
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    • pp.209-212
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    • 2004
  • In this paper, The stress induced leakage currents of thin silicon oxides is investigated in the nano scale structure implementation for Soc. The stress and transient currents associated with the on and off time of applied voltage were used to measure the distribution of high voltage stress induced traps in thin silicon oxide films. The stress and transient currents were due to the charging and discharging of traps generated by high stress voltage in the silicon oxides. The channel current for the thickness dependence of stress current, transient current, and stress induced leakage currents has been measured in oxides with thicknesses between $41\square\;and\;113.4\square,$ which have the channel width x length 10x1um, respectively. The stress induced leakage currents will affect data retention and the stress current, transient current is used to estimate to fundamental limitations on oxide thicknesses. The weight value of synapse transistor was caused by the bias conditions. Excitatory state and inhitory state according to weighted values affected the channel current. The stress induced leakage currents affected excitatory state and inhitory state.

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In0.5(Ga1-xAlx)0.5P/GaAs 이중 이종접합 구조의 Contactless Electroreflectance에 관한 연구 (Contactless Electroreflectance Spectroscopy of In0.5(Ga1-xAlx)0.5P/GaAs Double Heterostructures)

  • 김정화;조현준;배인호
    • 한국진공학회지
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    • 제19권2호
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    • pp.134-140
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    • 2010
  • Metal-organic chemical vapour deposition (MOCVD)법으로 성장된 $In_{0.5}(Ga_{1-x}Al_x)_{0.5}P$/GaAs 이중 이종접합 구조의 특성을 contactless electroreflectance (CER) 분광법으로 조사하였다. CER 측정은 변조전압($V_{ac}$), 온도 및 dc 바이어스 전압($V_{bias}$)의 함수로 수행하였다. 상온에서는 5개의 신호가 관측되었는데, 이 신호들은 각각 GaAs, $In_{0.5}Ga_{0.5}P$, $In_{0.5}(Ga_{0.73}Al_{0.27})_{0.5}P$, $In_{0.5}(Ga_{0.5}Al_{0.5})_{0.5}P$$In_{0.5}(Ga_{0.2}Al_{0.8})_{0.5}P$ 전이에 관련된 것이다. CER 스펙트럼의 온도 의존성으로부터 Varshni 계수 및 평탄인 자를 구하였다. 그리고 인가전압에 따른 신호의 진폭은 순방향 바이어스 전압 인가시 점차로 감소하나, 역방향 바이어스 전압 인가시에는 반대의 경향을 보였다.