• 전자공학회논문지D
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• 제35D권8호
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• pp.24-30
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• 1998

A blue LED of $In_{x}Ga_{1-x}N$ multiple quantum well structure which had the blue emission spectrum of donor-acceptor pair transition generated form Si-Zn co-doped $In_{x}Ga_{1-x}N$ active layer, was fabricated. The $In_{x}Ga_{1-x}N$ MQW heterojunction LED structure was grown by MOCVD on the sapphire substrate with (0001) surface orientation at 800.deg. C. The fabricated LED exhibited forward cut-in voltage of 4~4.5V and reverse breakdown voltage of -13V. Its optical chracteristics showed that the center wavelength of peak emission occurred at 460nm and the optical intensity was increased linearly with respect to the injected electrical current above 5mA.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2014년도 추계학술대회 논문집
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• pp.185-186
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• 2014

본 논문에서는 Si MOSFET 대비 GaN FET의 특성을 비교 분석하고, GaN FET의 장점을 활용할 수 있는 방안을 모색하였다. 그 결과 GaN FET의 우수한 reverse recovery 특성을 활용할 수 있는 토템폴 구조의 브리지리스 부스트 PFC 컨버터를 선정하였고, 선정한 회로의 동작 및 효율을 5.5kW급 프로토타입을 통하여 확인하였다.

• 한국전기전자재료학회논문지
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• 제19권8호
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• pp.775-779
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• 2006

In this study, sputtered $Al_2O_3$ thin films were evaluated as a passivation layer in the process of InGaN-based blue LEDs in order to improve the brightness of LED lamps. In terms of packaged LED lamps, lamps with $Al_2O_3$ passivation layer emanated higher brightness than those with $SiO_2$ passivation layer, and LED lamps with 90 nm $Al_2O_3$ passivation layer were the brightest among four kinds of lamps. Although lamps with $Al_2O_3$ passivation had a slight increase in operating voltage, their brightness was improved about 13.6 % compare to the lamps made of conventional LEDs without the changes of emitting wavelength.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2019년도 전력전자학술대회
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• pp.279-280
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• 2019

본 논문에서는 3KW급 전력변환장치에 적용 가능한 650V급 GaN FET를 사용하여 Half-bridge 구조의 개발보드를 설계 및 제작하고, Double pulse test 실험을 통해 Turn-on 및 off 시스위칭 특성을 분석하였다. 또한 동기정류식 Buck 컨버터에 GaN FET을 적용하고, 유사한 전압 및 전류 정격의 Si MOSFET 소자와 시스템 효율을 비교하여 GaN FET 전력반도체의 성능을 평가하였다.

• KIEE International Transactions on Electrophysics and Applications
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• 제3C권2호
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• pp.66-69
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• 2003

Various semiconductor nanowires such as GaN, GaP, InP, Si$_3$N$_4$, SiO$_2$/Si, and SiC were coated conformally with aluminum oxide (Al$_2$O$_3$) layers by atomic layer deposition (ALD) using trimethylaluminum (TMA) and distilled water ($H_2O$) at a temperature of 20$0^{\circ}C$. Transmission electron microscopy (TEM) revealed that A1203 cylindrical shells conformally coat the semiconductor nanowires. This study suggests that the ALD of $Al_2$O$_3$ on nanowires is a promising method for preparing cylindrical dielectric shells for coaxially gated nanowire field-effect transistors.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2006년도 추계학술발표대회 및 제11회 신소재 심포지엄
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• pp.3.2-3.2
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• 2006

• Journal of Power Electronics
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• 제9권1호
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• pp.36-42
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• 2009

This paper presents a review of an improved high power-high frequency III-V wide bandgap (WBG) semiconductor device, Gallium Nitride (GaN). The device offers better efficiency and thermal management with higher switching frequency. By having higher blocking voltage, GaN can be used for high voltage applications. In addition, the weight and size of passive components on the printed circuit board can be reduced substantially when operating at high frequency. With proper management of thermal and gate drive design, the GaN power converter is expected to generate higher power density with lower stress compared to its counterparts, Silicon (Si) devices. The main contribution of this work is to provide additional information to young researchers in exploring new approaches based on the device's capability and characteristics in applications using the GaN power converter design.

• 전력전자학회논문지
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• 제25권6호
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• pp.451-458
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• 2020

In this study, a trade-off analysis of a power conversion system (PCS) is performed in accordance with a power semiconductor device to establish the suitable operating frequency range for the anyplace induction heating system. A resonant network is designed under each operating frequency condition to compare and analyze the PCS losses depending on the power semiconductor device. On the basis of the simulation results, the PCS losses and frequency condition are calculated. The calculated results are then used for a trade-off analysis between Si-MOSFET and GaN-HEMT based on PCS. The suitable operating frequency range is determined, and the validity of the analysis results is verified by the experiment results.

• 한국재료학회지
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• 제3권6호
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• pp.645-651
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• 1993

Bulk반절연 기판 웨이퍼에 이온 주입법에 의한 기존의 GaAs집적회로 제작시 발생하는 문제점을 보완하고자 반절연 기판 위에 반절연성의 고저항 GaAs 에피층을 성장하는 연구를 수행하였다. 먼저 반절연 기판의 EPD분포를 조사하고, MOCVD와 MBE법을 이용하여 undeped GaAs반절연성 에피층을 성장시켜 실제 집적회로의 제작에 적합한지를 평가하였다. 평가방법은 반절연성 에피\ulcorner을 buffer층으로 성장시킨 에피 기판에 ungated FET를 제작하여, 이 반절연성 에피\ulcorner을 통한 누설전류를 측정하고, 또한 반절연 기판의 EP분호의 영향을 조사하였다. 누설 전류의 측정결과 비교적 주설 전류가 큰 1$\mu\textrm{m}$ 두께의 MOCVD시료에서도 270nA/mm로 FET의 pinch-off에는 영향을 주지 못하는 매우 작은 누설 전류 값을 나타내었다. 또한 누설전류의 분포가 반절연 기판의 EPD분포와 일치하는 것을 발견하여, 에피층의 quality에 기판의 결함이 미치는 영향을 확인하였다. MBE법으로 성장한 2$\mu\textrm{m}$ 두께의 undoped burrer층 시료는 휠씬 좋은 특성을 나타내었으며, 매우 균일하고 낮은 누설전류(40nA/mm)가 측정되었다.

• 한국전기전자재료학회논문지
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• 제23권11호
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• pp.848-853
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• 2010

We have grown GaN nanowires by the low pressure MOCVD method on Ni deposited oxidized Si surface and have established optimum conditions by observing surface microstructure and its photoluminescence. Optimum growth temperature of $880^{\circ}C$, growth time of 30 min, TMG source flow rate of 10 sccm have resulted in dense nanowires on the surface, however further increase of growth time or TMG flow rate has not increased the length of nanowire but has formed nanocrystals. On the contrary, the increase of ammonia flow has increased the length of nanowires and the coverage of nanowire over the surface. The shape of nanowire is needle-like with a Ni droplet at its tip; the length is tens of micron with more than 40 nm in diameter. Low temperature photoluminescence obtained from the sample at optimum growth condition has revealed several peaks related to exciton decay near band-edge, but does not show any characteristic originated from one dimensional quantum confinement. Strong and broad luminescence at 2.2 eV is observed from dense nanowire samples and this suggests that the broad band is related to e-h recombination at the surface state in a nanowire. The current result is implemented to the nanowire device fabrication by nanowire bridging between micro-patterned neighboring Ni catalysis islands.