• Title/Summary/Keyword: Depletion region

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Characterization of Thin $SiO_2/Si_3N_4$ Film on $WSi_2$ (텅스텐 실리사이드 상의 얇은 $SiO_2/Si_3N_4$ 막의 특성 평가)

  • 구경원;홍봉식
    • Journal of the Korean Vacuum Society
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    • v.1 no.1
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    • pp.183-189
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    • 1992
  • The characteristics of N/O(SiOz/SisN4) film on WSi2 are compared with storage node Poly-Si. Leakage current and breakdown voltage are improved and storage capacitance is decreased. The oxidation rate of WSiz is more rapid than polycrystalline silicon. Thus the thick bottom oxide on the WSiz causes to the decrease of capacitance. The out diffusion of dopant impurity in polycrystalline silicon through the silicide leads to the formation of a depletion region in the polycrystalline silicon and the decrease of depletion capacitance. That results in the decrease of the overall storage capacitance.

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Current Saturation Improvement of Poly-Si TFTs for Analog Circuit Integration

  • Nam, Woo-Jin;Han, Sang-Myeon;Lee, Hye-Jin;Han, Min-Koo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.289-292
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    • 2005
  • New poly-Si TFTs have been proposed and fabricated in order to increases the output channel resistance ($r_o$). The counter-doped($p^+$) source is tied to the $n^+$ source and is extended into the channel region so that it employs the reverse bias depletion in the channel. As $V_{DS}$ is increased, the depletion width is increased and the effective channel width is reduced. Therefore, the output current saturates well and the $r_o$ is increased successfully. The proposed CMOS devices may improve the amplifier gain of data driver in active-matrix displays

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Calculation of Forward Voltage Drop of IGBTs (IGBT 순방향 전압강하의 계산)

  • Choe, Byeong-Seong;Jeong, Sang-Gu
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.49 no.3
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    • pp.161-164
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    • 2000
  • A simple methode for calculating the forward voltage drop of IGBTs is presented, on the voltage drops on the p+ body, the reverse biased depletion region between p+body and epi-layer, the epi layer, and the forward biased collector junction. The decrease of the total current density in the epi layer near the p+ body is taken into account. The proposed methode allows a simple but accurate determination of the forward voltage drop in IGBTs, avoiding the complex path taken in the previous model for the forward voltage drops on channel, accumulation region, and epi region. Numerical simulations for 1kV NPT-IGBT with a uniformly doped collector are shown to support the analytical results.

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Quantum modulation of the channel charge and distributed capacitance of double gated nanosize FETs

  • Gasparyan, Ferdinand V.;Aroutiounian, Vladimir M.
    • Advances in nano research
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    • v.3 no.1
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    • pp.49-54
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    • 2015
  • The structure represents symmetrical metal electrode (gate 1) - front $SiO_2$ layer - n-Si nanowire FET - buried $SiO_2$ layer - metal electrode (gate 2). At the symmetrical gate voltages high conductive regions near the gate 1 - front $SiO_2$ and gate 2 - buried $SiO_2$ interfaces correspondingly, and low conductive region in the central region of the NW are formed. Possibilities of applications of nanosize FETs at the deep inversion and depletion as a distributed capacitance are demonstrated. Capacity density is an order to ${\sim}{\mu}F/cm^2$. The charge density, it distribution and capacity value in the nanowire can be controlled by a small changes in the gate voltages. at the non-symmetrical gate voltages high conductive regions will move to corresponding interfaces and low conductive region will modulate non-symmetrically. In this case source-drain current of the FET will redistributed and change current way. This gives opportunity to investigate surface and bulk transport processes in the nanosize inversion channel.

The Analysis of I-V characteristics on n-channel offset gated poly-Si TFT`s (Offset 구조를 갖는 n-채널 다결정 실리콘 박막 트랜지스터의 I-V 분석)

  • 변문기;이제혁;김동진;조동희;김영호
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.26-29
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    • 1999
  • The I-V characteristics of the n-channel offset gated poly-Si TETs have been systematically investigated in order to analyse the effects of offset region. The on currents are reduced due to the series resistance by the offset length and there is no kink phenomenon in offset devices. The off currents of the offset gated TFTs are remarkably reduced to 10$^{-12}$ A independent of gate and drain voltage because the electric field is weakened by the increase of the depletion region width near the drain region. It is shown that the offset regions behave as a series resistance and reduce lateral and vertical electric field.

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Effects of Peripheral Pentacene Region on C-V Characteristics of Metal-Oxide-Pentacene Capacitor Structure

  • Jung, Keum-Dong;Jin, Sung-Hun;Park, Chang-Bum;Shin, Hyung-Cheol;Park, Byung-Gook;Lee, Jong-Duk
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.1284-1287
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    • 2005
  • Peripheral pentacene region gives a significant influence on C-V characteristics of metal-oxide-pentacene capacitor structure. When the gate voltage goes toward negative, the effect of peripheral pentacene region becomes larger. Remaining gate DC bias constant and changing small signal frequency, the capacitance of peripheral pentacene changes along with frequency so that the total capacitance value also changes. The influence of peripheral pentacene region should be removed to measure accurate C-V characteristics, because it is hard to take into account the effect of the region quantitatively. After removing the influence of peripheral pentacene region, acceptor concentration, flat band voltage and depletion width of pentacene thin film are extracted from an accurate C-V curve as $1.58{\times}10^{17}cm^{-3}$, -1.54 V and 39.4 nm, respectively.

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Dietary Tea Catechin Inclusion Changes Plasma Biochemical Parameters, Hormone Concentrations and Glutathione Redox Status in Goats

  • Zhong, Rongzhen;Xiao, Wenjun;Ren, Guopu;Zhou, Daowei;Tan, Chuanyan;Tan, Zhiliang;Han, Xuefeng;Tang, Shaoxun;Zhou, Chuanshe;Wang, Min
    • Asian-Australasian Journal of Animal Sciences
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    • v.24 no.12
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    • pp.1681-1689
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    • 2011
  • The beneficial effects of tea catechins (TCs) are related not only to their antioxidant potential but also to the improvement of animal meat quality. In this study, we assessed the effects of dietary TC supplementation on plasma biochemical parameters, hormone responses, and glutathione redox status in goats. Forty Liuyang goats were randomly divided into four equal groups (10 animals/group) that were assigned to four experimental diets with TC supplementation at 4 levels (0, 2,000, 3,000 or 4,000 mg TC/kg DM feed). After a 60-day feeding trial, all goats were slaughtered and sampled. Dietary TC treatment had no significant effect on blood biochemical parameters, however, low-density lipoprotein cholesterol (p<0.001), triglyceride (p<0.01), plasma urea nitrogen (p<0.01), and glucose (p<0.001) decreased and total protein (p<0.01) and albumin (p<0.05) increased with the feeding time extension, and day 20 was the turning point for most of changes. Interactions were found in glutathione (p<0.001) and the ratio of reduced and oxidized glutathione (p<0.05) in whole blood between treatment and feeding time. Oxidized glutathione in blood was reduced (p<0.05) by 2,000 mg TC/kg feed supplementation, and a similar result was observed in longissimus dorsi muscle. Though plasma glutathione peroxidase (p<0.01) and glutathione reductase (p<0.05) activities were affected by treatment and feeding time interactions, and glutathione S-transferases activity increased with feeding day extension, no changed values appeared in longissimus dorsi muscle. In conclusion, dietary TC supplementation affected the concentrations of some blood metabolites and accelerated GSH depletion in the blood of goats. In terms of less high-density lipoprotein cholesterol, the highest insulin and IGF-I concentrations, the highest ratio of reduced and oxidized glutathione in plasma, the dosage of 2,000 mg TC/kg feed might be desirable for growing goats to prevent glutathione depletion and keep normal physiological metabolism.

Can relativistic electrons be accelerated in the geomagnetic tail region?

  • Lee, J.J.;Parks, G.K.;Min, K.W.;Lee, E.S.;McCarthy, M.P.;Hwang, J.A.;Lee, C.N.
    • Bulletin of the Korean Space Science Society
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    • 2008.10a
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    • pp.31.1-31.1
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    • 2008
  • While some observations in the geomagnetic tail region supported electrons could be accelerated by reconnection processes, we still need more observation data to confirm electron acceleration in this region. Because most acceleration processes accompany strong pitch angle diffusion, if the electrons were accelerated in this region, strong energetic electron precipitation should be observed near earth on aurora oval. Even though there are several low altitude satellites observing electron precipitation, intense and small scale precipitation events have not been identified successfully. In this presentation, we will show an observation of strong energetic electron precipitation that might be analyzed by relativistic electron acceleration in the confined region. This event was observed by low altitude Korean STSAT-1, where intense several hundred keV electron precipitation was seen simultaneously with 10 keV electrons during storm time. In addition, we observed large magnetic field fluctuations and an ionospheric plasma depletion with FUV aurora emissions. Our observation implies relativistic electrons can be generated in the small area where Fermi acceleration might work.

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FAR-INFRARED CHARACTERISTICS OF GIANT MOLECULAR CLOUDS (거대 분자운의 원적외선 특성)

  • Jung, Jae-Hoon;Kim, Hyun-Goo;Kim, Bong-Gyu
    • Publications of The Korean Astronomical Society
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    • v.21 no.2
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    • pp.27-33
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    • 2006
  • Infrared color-color diagram of 10 giant molecular clouds are examined to explore the dust property from the COBE Diffuse Infrared Background Experiment of the 100, 140, and $240{\mu}m$ emission. Four of them, Taurus, Mon OB1, Gem OB1, and Chameleon, show the anti-correlation in $R_{100/140}-R_{140/240}$ plot and the horizontal distribution in $R_{100/240}-R_{140/240}$ plot, which disagree with those of theoretical calculation. These could be explained by the depletion of $100{\mu}m$ and the excess of $140{\mu}m$ emission, though no existing dust model could support them. Mean color temperature of the anti-correlation region appears to be lower than that of the linear region, whose temperatures are 15.3, 17.0 K, respectively. And the linear region shows large dispersion in the plot of intensity relation. Both imply that a star formation would be more active, but not homogeneous, in the linear region compared to the anti-correlation region.

Effect of Heat Treatments on Tungsten Polycide Gate Structures (텅스텐 폴리사이드 게이트 구조에서의 열처리 효과)

  • 고재석;천희곤;조동율;구경완;홍봉식
    • Journal of the Korean Vacuum Society
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    • v.1 no.3
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    • pp.376-381
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    • 1992
  • Tungsten silicide films were deposited on the highly phosphorus-doped poly Si/SiO2/Si substrates by Low Pressure Chemical Vapor Deposition. They were heat treated in different conditions. XTEM, SIMS and high frequency C-V analysis were conducted for characterization. It can be concluded that outdiffusion of phosphours impurity throught the silicide films lead to its depletion in the poly-Si gate region near the gate oxide, resulting in loss of capacitance and increase of effective gate oxide thickness.

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