• Title/Summary/Keyword: Kink effect

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Stability Enhancement of Polysilicon Thin-Film Transistors with A Source-tied-to-body

  • Choi, B.D.;Choi, D.C.;Jung, J.Y.;Park, H.H.;Chung, H.K.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.293-293
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    • 2005
  • The differences between floating and grounded body effects in polycrystalline silicon thin-film transistors (polysilicon TFTs) are investigated by making a body contact. The floating body effects such as kink effect, subthreshold slope change, and body current characteristics are explained and modeled by impact ionization, which causes source body turn on, and activates the parasitic bipolar junction transistors (BJTs). These effects become crucial for channel lengths of 4㎛ or shorter. Our data show that making a body contact reduces kink effects significantly and identifies impact ionization mechanism in polysilicon TFTs.

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Lateral Far-field Characteristics of Narrow-width 850 nm High Power GaAs/AlGaAs Laser Diodes

  • Yang, Jung-Tack;Kwak, Jung-Geun;Choi, An-Sik;Kim, Tae-Kyung;Choi, Woo-Young
    • Current Optics and Photonics
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    • v.6 no.2
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    • pp.191-195
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    • 2022
  • We investigate the lateral far-field pattern characteristics, including divergence angle change and far-field pattern analysis as output power increases, of narrow-emitter-width 850 nm GaAs/AlGaAs laser diodes (LDs). Each LD has a cavity of 1200 and 1500 ㎛ and narrow emitter width of 2.4 ㎛ for the top and 4.6 ㎛ for the bottom. The threshold currents are 35 and 40 mA, and L-I kinks appear at power levels of 326 and 403 mW, respectively. The divergence angle tends to increase due to the occurrence of first-order lateral mode and the thermal lensing effect. But with the L-I kink, the divergence angle decreases and the far-field pattern becomes asymmetric. This is due to coherent superposition between the fundamental and the first-order lateral mode. We provide detailed explanations for these observations based on high-power laser diode simulation results.

Design of Mini-LVDS Output Buffer using Low-Temperature Poly-Silicon (LTPS) thin-film transistor (TFT)

  • Nam, Young-Jin;Min, Kyung-Youl;Yoo, Chang-Sik
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.685-688
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    • 2008
  • Mini-LVDS has been widely used for high speed data transmission because it provides low EMI and high bandwidth for display driver. In this paper, a Mini-LVDS output buffer with LTPS TFT process is presented which provides sufficient performance in the presence of large variation in the threshold voltage and mobility and kink effect.

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A simple model and parameter extraction method for the description of ON-current of LT-PS TFT

  • Chung, De-Will;Park, Jun-Young;Park, Sang-Gyu
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.759-762
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    • 2006
  • A simple SPICE model for the description of the on-current of low-temperature poly-silicon thin film transistors is proposed. By employing constant mobility, $V_GS$ dependent alpha parameter, and exponential kink effect, very good agreements between the model and measurement were obtained.

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Fabrication of the Recrystallized Poly Silicon nMOSFET and Its Electrical Characteristics (재결정화된 다결정 nMOSFET의 제작 및 그 전기적 특성)

  • Kim, Joo-Young;Kang, Moun-Sang;Kim, Gi-Hong;Ku, Yong-Seo;An, Chul
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.29A no.11
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    • pp.91-96
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    • 1992
  • The technology of LOCOS(LOCal Oxidation of Silicon) was used to form the island of SOI film. After this, the SOI film was recrystallized by CO$_2$ laser and metal gate nMOSFETs were fabricated on this SOI film and their electrical characteristics were measured. The kink effect was not nearly observed and edge channel effect was found in the SOI nMOSFETs. The threshold voltage was about 0.5V, the electron mobility was about 340cm$^2$V$\cdot$S and an ON/OFF ratio above 10$^{5}$ was obtained at V_{DS}$=4V. The electrical characteristics were improved by laser recrystallization.

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Shielding Effects of Bimaterial Interfaces by Crack Surface Asperities (균열 표면거칠기에 의한 이종재료 계면의 차단효과)

  • 채영석;권용수;최병선
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.3
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    • pp.540-547
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    • 1994
  • Contact and frictional locking conditions and the effect of shielding due to contact at the facet, which could be represented by the difference in energy release rate, as a function of phase angle of loading are analyzed in this study for the case of interfacial cracks by assuming single crack-kink model. The analysis of contact effects on interfacial fracture resistance shows that relative shielding increases as the shear component was increased, which indicates a qualitative agreement with the previous experimental results.

Memory Characteristics of 1T-DRAM Cell by Channel Structure (채널 구조에 따른 1T-DRAM Cell의 메모리 특성)

  • Jang, Ki-Hyun;Jung, Seung-Min;Park, Jin-Kwon;Cho, Won-Ju
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.2
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    • pp.96-99
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    • 2012
  • We fabricated fully depleted (FD) SOI-based 1T-DRAM cells with planar channel or recessed channel and the electrical characteristics were investigated. In particular, the dependence of memory operating mode on the channel structure of 1T-DRAM cells was evaluated. As a result, the gate induced drain leakage current (GIDL) mode showed a better memory property for planar type 1T-DRAM. On the other hand, the impact ionization (II) mode is more effective for recessed type.

Reliability of Low Temperature Poly-Si TFT employing Counter-doped Lateral Body Terminal (저온 다결정 실리콘 박막 트랜지스터의 신뢰도 향상을 위한 Counter-doped Lateral Body Terminal (CLBT) 구조)

  • Kim, J.S.;Yoo, J.S.;Kim, C.H.;Lee, M.C.;Han, M.K.
    • Proceedings of the KIEE Conference
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    • 2001.07c
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    • pp.1442-1444
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    • 2001
  • A new low-temperature poly-Si TFT employing a counter-doped lateral body terminal is proposed and fabricated, in order to enhance the stability of poly-Si TFT driving circuits. The LBT structure effectively suppresses the kink effect by collecting the counter-polarity carriers and suppresses the hot carrier effect by reducing the peak lateral field at the drain junction. The proposed device is immune to dynamic stress, so that it is suitable for low voltage and high speed driving circuits of AMLCD.

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Feasibility Study of Non-volatile Memory Device Structure for Nanometer MOSFET (나노미터 MOSFET비휘발성 메모리 소자 구조의 탐색)

  • Jeong, Ju Young
    • Journal of the Semiconductor & Display Technology
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    • v.14 no.2
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    • pp.41-45
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    • 2015
  • From 20nm technology node, the finFET has become standard device for ULSI's. However, the finFET process made stacking gate non-volatile memory obsolete. Some reported capacitor-less DRAM structure by utilizing the FBE. We present possible non-volatile memory device structure similar to the dual gate MOSFET. One of the gates is left floating. Since body of the finFET is only 40nm thick, control gate bias can make electron tunneling through the floating gate oxide which sits across the body. For programming, gate is biased to accumulation mode with few volts. Simulation results show that the programming electron current flows at the interface between floating gate oxide and the body. It also shows that the magnitude of the programming current can be easily controlled by the drain voltage. Injected electrons at the floating gate act similar to the body bias which changes the threshold voltage of the device.

Influence of AC Frequency on the Liquid Breakup in Electrohydrodynamic Atomization (전기수력학적 미립화에서 교류 주파수가 액적 분열에 미치는 영향)

  • Sung, K.A.;Lee, C.S.
    • Journal of ILASS-Korea
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    • v.9 no.2
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    • pp.41-49
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    • 2004
  • Liquid breakup under the variation of AC frequency has been studied experimentally in the electrohydrodynamic atomization. The effect of parameters such as charging voltage, flow rate, nozzle tip inner diameter and power frequency have been considered. This work was performed to investigate the experimental analysis for the effect of AC frequency on breakup process, the mapping of occurrence of disintegration region, and the relationship between the applied power and the droplet radius. The experimental results show that the increase of applied voltage in a certain frequency band leads to a reduction in the droplet size within the limits from 50Hz to 400Hz. The transition phenomena from dripping mode to spindle mode were observed under the band of sudden fall of droplet radius changing ratio, and the synchronous region were produced within the range of applied voltage from 5kV to 6kV.

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