• Title/Summary/Keyword: carrier trapping

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A Study on Radiation Hardening of a Infrared Detector (적외선 탐지소자의 내방사선화 연구)

  • Lee, Nam-Ho;Kim, Seung-Ho;Kim, Young-Ho
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.54 no.11
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    • pp.490-492
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    • 2005
  • A study on radiation hardening of infrared(IR) detector, the chief component of IR camera was performed. The radiation test on IR sensor passivated with the ZnS by Co$^{60}$ gamma-ray over 1 Mrads showed the reduction in Ro by 1/100 which was related to the noise level. This effect that was caused by carrier trapping in the ZnS passivation layer increased the leakage current and resulted in degradation in the device performance. For the radiation hardening of IR devices we suggested the ones with CdTe passivation layer which had a tendency to reluctant to carrier trapping in its layer and developed test patterns. Radiation test to the patterns showed that the our CdTe passivated device could survived over 1 Mrad gamma-ray dose.

A Study on Carrier Injection and Trapping by the High Field for MAS (Al-Al2O3-Si(n)) Structure ($Al-Al_2O_3-Si$(N형)의 MAS 구조에 있어서 고전계에 의한 Carrier 주인과 트?에 관한 연구)

  • 이영희;박성희
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.35 no.10
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    • pp.465-472
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    • 1986
  • The present study was carried out to investigate the mechanism which control the voltage instability and the breakdown of CVD Al2O3 on Si substrates. Our sample were metal-Al2O3-Oi Capacitors with both Al and Au field plates. Electron injection and trapping, with resultant positive flatband voltage shift, occur at fields as low as 1-2[MV/cm.] We developed an approximate method for computing the location of the centroid of the trapped electrons. Our results indicate that the electrons are trapped near the injecting interface, at least for fields less than about 5[MV/cm ] Because of continued charging, a true steady state is probably never reached, and the only unique I-V curve is the one obtained initially, when the traps are empty. We measured this I-V curve for both polarities of applied voltage, using a fresh sample for each point. The observed current densities are much larger than those obtained in thermally grawn SiO2.

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Algorithm for Halftone Generation for Gravure Engraving (그라비어 조각용 망점화 알고리즘)

  • 윤종태
    • Journal of the Korean Graphic Arts Communication Society
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    • v.16 no.1
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    • pp.13-24
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    • 1998
  • The color difference caused by the overprinting sequence of ink in multicolor printing is due to both trapping and optical properties of ink layers. Hence the effect of optical properties only cannot be analyzed without removing the effect of ink trapping This study was carrier out for the purpose of analyzing optically the color difference caused by only the optical properties of ink under the various printing sequence. The present optical analysis for overprints showed a good agreement with the experimental result. It is expected that this study may contribute to decreasing the color difference between the original and the printed reproduction in multi-color printing.

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A Study on Characteristics of Wet Oxide Gate and Nitride Oxide Gate for Fabrication of NMOSFET (NMOSFET의 제조를 위한 습식산화막과 질화산화막 특성에 관한 연구)

  • Kim, Hwan-Seog;Yi, Cheon-Hee
    • The KIPS Transactions:PartA
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    • v.15A no.4
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    • pp.211-216
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    • 2008
  • In this paper we fabricated and measured the $0.26{\mu}m$ NMOSFET with wet gate oxide and nitride oxide gate to compare that the charateristics of hot carrier effect, charge to breakdown, transistor Id_Vg curve, charge trapping, and SILC(Stress Induced Leakage Current) using the HP4145 device tester. As a result we find that the characteristics of nitride oxide gate device better than wet gate oxide device, especially hot carrier lifetime(nitride oxide gate device satisfied 30 years, but the lifetime of wet gate oxide was only 0.1 year), variation of Vg, charge to breakdown, electric field simulation and charge trapping etc.

Analysis of Positive Bias Temperature Instability Degradation Mechanism in n+ and p+ poly-Si Gates of High-Voltage SiO2 Dielectric nMOSFETs (고전압 SiO2 절연층 nMOSFET n+ 및 p+ poly Si 게이트에서의 Positive Bias Temperature Instability 열화 메커니즘 분석)

  • Yeohyeok Yun
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.16 no.4
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    • pp.180-186
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    • 2023
  • Positive bias temperature instability (PBTI) degradation of n+ and p+ poly-Si gate high-voltage(HV) SiO2 dielectric nMOSFETs was investigated. Unlike the expectation that degradation of n+/nMOSFET will be greater than p+/nMOSFET owing to the oxide electric field caused by the gate material difference, the magnitude of the PBTI degradation was greater for the p+/nMOSFET than for the n+/nMOSFET. To analyze the cause, the interface state and oxide charge were extracted for each case, respectively. Also, the carrier injection and trapping mechanism were analyzed using the carrier separation method. As a result, it has been verified that hole injection and trapping by the p+ poly-Si gate accelerates the degradation of p+/nMOSFET. The carrier injection and trapping processes of the n+ and p+ poly-Si gate high-voltage nMOSFETs in PBTI are detailed in this paper.

Characterization of Hot Carrier Mechanism of Nano-Scale CMOSFETs (나노급 소자의 핫캐리어 특성 분석)

  • Na Jun-Hee;Choi Seo-Yun;Kim Yong-Goo;Lee Hi-Deok
    • Proceedings of the IEEK Conference
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    • 2004.06b
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    • pp.327-330
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    • 2004
  • It is shown that the hot carrier degradation due to enhanced hot holes trapping dominates PMOSFETs lifetime both in thin and thick devices. Moreover, it is found that in 0.13 ${\mu}m$ CMOSFET the PMOS lifetime under CHC (Channel Hot Carrier) stress is lower than the NMOSFET lifetime under DAHC (Drain Avalanche Hot Carrier) stress. Therefore. the interface trap generation due to enhanced hot hole injection will become a dominant degradation factor. In case of thick MOSFET, the degradation by hot carrier is confirmed using charge pumping current method and highly necessary to enhance overall device lifetime or circuit lifetime in upcoming nano-scale CMOS technology.

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Charge Confinement and Interfacial Engineering of Electrophosphorescent OLED

  • Chin, Byung-Doo;Lee, Chang-Hee
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08b
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    • pp.1203-1205
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    • 2007
  • Confinement of charge carrier and exciton is the essential factor for enhancing the efficiency and stability of the electrophosphorescent devices. The interplay between the properties of emitters and other adjacent layers are studied based on the physical interpretation with difference of energy level, charge carrier mobility, and corresponding charge-trapping behavior.

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Current Status in Light Trapping Technique for Thin Film Silicon Solar Cells (박막태양전지의 광포획 기술 현황)

  • Park, Hyeongsik;Shin, Myunghoon;Ahn, Shihyun;Kim, Sunbo;Bong, Sungjae;Tuan, Anh Le;Hussain, S.Q.;Yi, Junsin
    • Current Photovoltaic Research
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    • v.2 no.3
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    • pp.95-102
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    • 2014
  • Light trapping techniques can change the propagation direction of incident light and keep the light longer in the absorption layers of solar cells to enhance the power conversion efficiency. In thin film silicon (Si) solar cells, the thickness of absorption layer is generally not enough to absorb entire available photons because of short carrier life time, and light induced degradation effect, which can be compensated by the light trapping techniques. These techniques have been adopted as textured transparent conduction oxide (TCO) layers randomly or periodically textured, intermediate reflection layers of tandem and triple junction, and glass substrates etched by various patterning methods. We reviewed the light trapping techniques for thin film Si solar cells and mainly focused on the commercially available techniques applicable to textured TCO on patterned glass substrates. We described the characterization methods representing the light trapping effects, texturing of TCO and showed the results of multi-scale textured TCO on etched glass substrates. These methods can be used tandem and triple thin film Si solar cells to enhance photo-current and power conversion efficiency of long term stability.

Effects of Doping in Organic Electroluminescent Devices Doped with a Fluorescent Dye

  • Kang, Gi-Wook;Ahn, Young-Joo;Lee, Chang-Hee
    • Journal of Information Display
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    • v.2 no.3
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    • pp.1-5
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    • 2001
  • The effect of doping on the energy transfer and charge carrier trapping processes has been studied in organic light-emitting diodes (OLEDs) doped with a fluorescent laser dye. The devices consisted of N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1-biphenyl-4,4'-diamine (TPD) as a hole transporting layer, tris(8-hydroxyquinoline) aluminum ($Alq_3$) as the host, and a fluorescent dye, 4-dicyanomethylene-2-methyl-6-[2-(2,3,6,7-tetrahydro-1 H,5H-benzo[i,j]quinolizin-8-yl) vinyl]-4H-pyran) (DCM2) as the dopant. Temperature dependence of the current-voltage-luminescence (I-V-L) characteristics, the electroluminescence (EL) and photoluminescence (PL) spectra are studied in the temperature ranging between 15 K and 300 K. The emission from DCM2 was seen to be much stronger compared with the emission from $Alq_3$, indicative of efficient energy transfer from $Alq_3$ to DCM2. In addition, the EL emission from DCM2 increasd with increasing temperature while the emission from the host $Alq_3$ decreased. The result indicates that direct charge carrier trapping becomes efficient with increasing temperature. The EL emission from DCM2 shows a slightly sublinear dependence on the current density, implying the enhanced quenching of excitons at high current densities due to the exciton-exciton annihilation.

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Study on the Trap Parameters according to the Nitridation Conditions of the Oxide Films (산화막의 질화 조건에 따른 트랩 파라미터에 관한 연구)

  • Yoon, Woon-Ha;Kang, Seong-Jun;Joung, Yang-Hee
    • The Journal of the Korea institute of electronic communication sciences
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    • v.11 no.5
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    • pp.473-478
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    • 2016
  • In this paper, the MIS(: Metal-Insulator-Semiconductor) Capacitor with the nitrided-oxide by RTP are fabricated to investigate the carrier trap parameters due to avalanche electron injection. Two times turn-around phenomenon of the flatband voltage shift generated by the avalanche injection are observed. This shows that electron trapping occurs in the oxide film at the first stage. As the electron injection increases, the first turn-around occures due to a positive charge in the oxide layer. After further injection, the curves turns around once again by electron captured. Based on the experimental results, the carrier trapping model for system having multi-traps is proposed and is fitting with experimental data in order to determine trap parameter of nitrided-oxide.