• 전기전자학회논문지
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• 제20권2호
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• pp.181-183
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• 2016

탄화규소(Silicon Carbide) 기반의 1200 V급 Merged Pin Schottky(MPS) 다이오드의 구조를 2D-atlas simulation tool을 사용하여 최적화 및 설계하였다. 최적화된 항복전압과 온-저항 값을 얻기 위해 본 소자에서 중요한 파라미터인 P-Grid의 도핑농도와 에피층의 도핑농도를 각각 $2{\sim}10{\times}10^{17}cm^{-3}$, $2{\sim}10{\times}10^{16}cm^{-3}$으로 변화시키면서 소자의 전기적 특성을 분석하였으며, 그 후 P-Grid의 Space값을 $1{\sim}5{\mu}m$로 설계하여 이에 따른 항복전압과 온-저항의 값을 확인하였다. 항복전압과 온-저항은 서로 trade-off 관계에 있기 때문에 각 변수에서 도출된 값들을 Baliga's Figure Of Merit (BFOM)식에 대입하여 비교하였다. 그 결과 고전압 소자에 적용 가능한 1200 V급 4H-SiC MPS다이오드를 최적화 및 설계를 도출하였다.

• Transactions on Electrical and Electronic Materials
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• 제17권5호
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• pp.293-296
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• 2016

Using capacitance-voltage (C-V) and conductance-voltage (G/ω-V) measurements, the electrical properties of Cu/n-InP Schottky diodes were investigated. The values of C and G/ω were found to decrease with increasing frequency. The presence of interface states might cause excess capacitance, leading to frequency dispersion. The negative capacitance was observed under a forward bias voltage, which may be due to contact injection, interface states or minority-carrier injection. The barrier heights from C-V measurements were found to depend on the frequency. In particular, the barrier height at 200 kHz was found to be 0.65 eV, which was similar to the flat band barrier height of 0.66 eV.

• 전자공학회논문지A
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• 제33A권4호
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• pp.106-111
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• 1996

Schottky diodes are fabricated on laser annealed and unannealed polysilicon substrate and their electrical characteristics are studied and analyzed. Current of laser annealed devices are larger than that of unannealed devices because of grain growth, decrease of grain boundary and trap density, lowering of grain boundary barrier height, decrease of dopant segregation. At low forward bias (<0.7V), currents of unanealed devices are larger. Soft breakdown voltages of laser annealed devices are larger than that of unannealed devices.

• JSTS:Journal of Semiconductor Technology and Science
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• 제4권2호
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• pp.124-127
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• 2004

W/n-GaN Schottky diodes were irradiated with $^{60}Co\;{\gamma}-rays$ to doses up to 315Mrad. The barrier height obtained from current-voltage (I-V) measurements showed minimal change from its estimated initial value of ${\sim}0.4eV$ over this dose range, though both forward and reverse I-V characteristics show evidence of defect center introduction at doses as low as 150 Mrad. Post irradiation annealing at $500^{\circ}C$ increased the reverse leakage current, suggesting migration and complexing of defects. The W/GaN interface is stable to high dose of ${\gamma}-rays$, but Au/Ti overlayers employed for reducing contact sheet resistance suffer from adhesion problems at the highest doses.

• 한국전기전자재료학회논문지
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• 제24권4호
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• pp.280-284
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• 2011

Silicon carbide (SiC)-based gas sensors can be operated at very high temperatures. So far, catalytic metal-schottky diodes respond fast to a change between a reducing and an oxidizing atmosphere. Therefore SiC diodes have been suggested for high temperature gas sensor applications. In this work, the effect of reactivity of the catalytic surface on the 4H-SiC sensor-structures in 375 K~775 K have been studied and some fundamental simulations have also been performed.

• 한국전기전자재료학회논문지
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• 제14권7호
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• pp.533-538
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• 2001

The barrier height is found to increase from 0.25 to 0.690 eV for Schottky contacts on n-InGaAs using deposition of Ag on a substrate cooled to 77K(LT). Surface analysis leads to an interface model for the LT diode in which there are oxide compounds of In:O and As:O between the metal and semiconductor, leading to behavior as a metal-insulator-semiconductor diode. The metal film deposited t LT has a finer and more uniform structure, as revealed by scanning electron microscopy and in situ metal layer resistance measurement. This increased uniformity is an additional reason for the barrier height improvement. In contrast, the diodes formed at room temperature exhibit poorer performance due to an unpassivated surface and non-uniform metal coverage on a microscopic level.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1733-1736
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• 2008

ZnO thin films with preferred orientation along the (0 0 2) plane were fabricated by a sol-gel method. The effects of the annealing temperature, time, and thickness were studied by investigating UV-visible spectra, FT-IR spectra, and XRD of ZnO films. The films were dried and annealed ed at $100^{\circ}C,\;200^{\circ}C$, and $300^{\circ}C$ for 1hr, 2hrs, and 3hrs, respectively. The film showed the preferred (0 0 2) orientation and high transmittance near 90% in the visible range. Also, SEM images of the films exhibited very smooth surfaces without holes and cracks. Schottky diodes were fabricated by using ZnO sol-gel material. Au and Al were used as electrodes to make Ohmic and Schottky contacts, respectively. The annealing temperature, time and the thickness dependent I-V characteristics were presented in this article.

• Transactions on Electrical and Electronic Materials
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• 제16권4호
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• pp.187-189
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• 2015

A charge-trap flash (CTF) thin film transistor (TFT) memory is proposed at a low-temperature process (≤ 450℃). The memory cell consists of a sputtered oxide-nitride-oxide (ONO) gate dielectric and Schottky barrier (SB) source/drain (S/D) junctions using nickel silicide. These components enable the ultra-low-temperature process to be successfully achieved with the ONO gate stacks that have a substrate temperature of room temperature and S/D junctions that have an annealing temperature of 200℃. The silicidation process was optimized by measuring the electrical characteristics of the Ni-silicided Schottky diodes. As a result, the Ion/Ioff current ratio is about 1.4×10⁵ and the subthreshold swing and field effect mobility are 0.42 V/dec and 14 cm²/V·s at a drain voltage of −1 V, respectively.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.192-195
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• 2001

In this report, we firstly have investigated the electrical characteristics of silicon carbide (SiC) schottky barrier diode and compared the characteristics to those of conventional Si diode through simulation and experiment. Secondly we have investigated the influence of two kinds of diodes to the power conversion circuit of the systems. From the investigation results it is verified that SiC schottky barrier diode is more superior to Si diode in thermal and reverse recovery, characteristics, which are the important factors in the size reduction and higher reliability of the systems. Finally though the experiment applied to PFC(Power Factor Correction) circuits, we precisely verified excellency to thermal characteristic of SiC schottky barrier diode any other diode.

• 한국진공학회지
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• 제16권3호
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• pp.197-204
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• 2007

p-형 실리콘 기판 위에 수 ${\AA}$ 두께의 어븀 금속을 증착하고, 후열처리 과정을 통하여 어븀-실리사이드/p-형 실리콘 접합을 형성하였다. 초고진공 자외선 광전자 분광 실험을 통하여 증착한 어븀의 두께에 따라 어븀-실리사이드의 일함수가 4.1 eV까지 급하게 감소하는 것을 관찰하였으며, X-ray 회절 실험에 의하여 형성된 어븀 실리사이드가 주로 $Er_5Si_3$상으로 구성되어 있음을 밝혔다. 또한, 어븀-실리사이드/p-형 실리콘 접합에 알루미늄 전극을 부착하여 쇼트키 다이오드를 제작하고, 전류전압 곡선을 측정하여 쇼트키 장벽의 높이를 산출하였다. 산출된 쇼트키 장벽의 높이는 $0.44{\sim}0.78eV$이었으며 어븀 두께 변화에 따른 상관 관계를 찾기 어려웠다. 그리고 이상적인 쇼트키 접합을 가정하고 이미 측정한 일함수로부터 산출한 쇼트키 장벽의 높이는 전류-전압 곡선으로부터 산출한 값에 크게 벗어났으며, 이는 어븀-실리사이드가 주로 $Er_5Si_3$ 상으로 구성되어 있고, $Er_5Si_3/p-$형 실리콘 계면에 존재하는 고밀도의 계면 상태에 기인한 것으로 사료된다.