• 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.

• 한국결정학회지
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• 제9권2호
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• pp.131-137
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• 1998

결정결함의 밀도가 낮은 GaN epitaxy 막을 MOCVD(metal organic chemical vapour deposition) 방법에 의해 성장시켰다. 기판은 6H-SiC를 사용하였으며, AlN과 GaN으로 구성된 이중 buffer 층을 도입하였다. GaN buffer 층은 반응원료인 trimethyl gallium(TMG)과 NH3 가스를 교호식펄스공급(alternating pulsative supply, APS)방법에 의해 만들었다. AlN buffer/6H-SiC 위에 초기단계에 형성되는 GaN 섬은 APS처리에 의해 크기가 커지는 것을 AFM(atomic force microscope)으로 관찰하였다. Buffer 층의 역할은 그 위에 성막시킨 GaN epitaxy 막의 결정성과 결함밀도에 의해 조사하였다. 성막된 GaN의 결정구조와 결정성은 DCXRD(double crystal X-ray diffractormeter)에 의해 측정되었다. 결정결함은 EPD(etching pit density)를 측정하는 방법으로 알칼리혼합용에서 처리된 막을 SEM(scanning electron microscope)으로 관찰하였다.

• International Journal of Internet, Broadcasting and Communication
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• 제12권2호
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• pp.30-36
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• 2020

We demonstrated a successful fabrication of 4" Gallium Nitride (GaN)/Diamond High Electron Mobility Transistors (HEMTs) incorporated with Inner Slot Via Hole process. We made in manufacturing technology of 4" GaN/Diamond HEMT wafers in a compound semiconductor foundry since reported [1]. Wafer thickness uniformity and wafer flatness of starting GaN/Diamond wafers have improved greatly, which contributed to improved processing yield. By optimizing Laser drilling techniques, we successfully demonstrated a through-substrate-via process, which is last hurdle in GaN/Diamond manufacturing technology. To fully exploit Diamond's superior thermal property for GaN HEMT devices, we include Aluminum Nitride (AlN) barrier in epitaxial layer structure, in addition to conventional Aluminum Gallium Nitride (AlGaN) barrier layer. The current collapse revealed very stable up to Vds = 90 V. The trapping behaviors were measured Emission Microscope (EMMI). The traps are located in interface between Silicon Nitride (SiN) passivation layer and GaN cap layer.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.5-5
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• 2010

Gallium Nitride(GaN)는 LED, Laser 등에 사용되는 광학적 특성뿐만 아니라 Wide Bandgap의 전기적 특성 또한 주목받고 있다. 본 논문은 600V급 GaN(Gallium Nitride) Power SIT(Static Induction Transistor)에 대해서 Design Parameter 변환에 따른 전기적 (Breakdown Voltgage, On-state Voltage Drop)특성과 열적 (Lattice Temperature Distribution)특성변화를 분석하여 소자가 갖는 구조적 손실을 최소화하였다. 또한, 기존 실리콘 기반 전력소자와 특성 비교를 통하여 GaN Power SIT의 우수성을 증명하였다. GaN Power SIT 소자 설계 및 최적화를 위해서 Silvaco사의 소자 시뮬레이터인 ATLAS를 사용하였다. 실험 결과 수 ${\mu}m$의 소자 두께만으로도 실리콘 전력소자에 비해 더 뛰어난 열 특성과 더 적은 전력소모를 갖는 600V급 GaN Power SIT 소자를 구현할 수 있었다.

• Journal of Power Electronics
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• 제15권6호
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• pp.1489-1498
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• 2015

Gallium nitride (GaN)-based power switching devices, such as high-electron-mobility transistors (HEMT), provide significant performance improvements in terms of faster switching speed, zero reverse recovery, and lower on-state resistance compared with conventional silicon (Si) metal-oxide-semiconductor field-effect transistors (MOSFET). These benefits of GaN HEMTs further lead to low loss, high switching frequency, and high power density converters. Through simulation and experimentation, this research thoroughly contributes to the understanding of performance characterization including the efficiency, loss distribution, and thermal behavior of a 160-W GaN-based synchronous boost converter under various output voltage, load current, and switching frequency operations, as compared with the state-of-the-art Si technology. Original suggestions on design considerations to optimize the GaN converter performance are also provided.

• 전기화학회지
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• 제17권1호
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• pp.1-6
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• 2014

본 총설은 질화 갈륨(GaN)을 이용한 광전기화학적 물분해 연구에 대해 정리하였다. GaN는 화학적으로 안정하고 에너지 띠간격 조절이 자유롭다는 장점으로 최근 물분해를 위한 새로운 광전극 물질로 연구되고 있다. 다른 화합물 반도체 물질은 강산 혹은 강염기 전해액에 의해 쉽게 부식되기 때문에 광산화전극(photoanode)으로는 사용이 어려운 반면, n형 GaN는 뛰어난 안정성 덕분에 산화 분위기의 산소 발생 전극으로도 활용이 가능하다. 또한, 최근에는 p형 GaN을 환원전극으로 이용한 광전극에 대한 연구도 보고되었다. GaN 물질이 실제 응용되기 위해 필요한 과제들에 대해 다루었다.

• 전기학회논문지
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• 제65권10호
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• pp.1664-1671
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• 2016

This paper presents the analysis of the gate-source voltage of the gallium nitride high electronic mobility transistor (GaN HEMT) in the half bridge structure focused on the mutual effects of two switching operation. Especially low side gate-source voltage is analyzed mathematically according to the high side switch turn-on and turn-off operation. Moreover, the influence of each gate resistance and parasitic component on the switching characteristic of other side switch is investigated, and the formula, simulation and experimental results are compared with theoretical data.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(2)
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• pp.217-220
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• 2001

Modified Materka-Kacprzak 대신호 MODFET(modulation-doped field-effect transistor) model을 사용하여 GaN(gallium nitride) MODFET 대신호 모델링을 수행하였다. Dambrine(3)이 제안한 방법에 따라 45㎒에서 40㎒의 주파수 범위에 걸쳐 S-parameter 및 DC특성을 측정하였으며, 측정결과를 토대로 cold FET 방법［4］에 의해 측정된 기생성분들을 de-embedding 함으로써 소신호 파라미터를 추출하였고, 추출된 소신호 파라미터는 함수를 사용하여 측정결과를 재현하는 맞춤함수 모델의 일종인 modified Materka 모델을 사용하여 모델링하였다. 수행된 대신호 모델링을 검증하기 위하여 모델링된 GaN MODFET의 DC 및 S-파라미터, 전력특성을 측정값과 각각 비교해 보았을 때 비교적 일치하고 있음을 보여서 GaN 대신호 모델링을 검증하였으며, modified Materka 모델이 GaN MODFET 대신호 모델링에 유용하게 사용될 수 있음을 보였다.

• 전력전자학회논문지
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• 제19권3호
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• pp.283-289
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• 2014

This paper carries out a series of analysis of power system using Gallium Nitride (GaN) FET which has wide band gap (WBG) characteristics comparing to conventional Si MOSFET-used power system. At first, for comparison of each semiconductor device, the switching-transient parameter is quantitatively extracted from released information of GaN FET. And GaN FET model which reflect this dynamic property is configured. By using this model, the performance of GaN FET is analyzed comparing to Si MOSFET. Also, in order to enable a representative assessment on the power system level, Si MOSFET and GaN FET are applied to the most common structure of power system, full-bridge, and each power systems are compared based on various criteria, such as performance, efficiency and power density. The entire process is verified with the aid of mathematical analysis and simulation.

• 한국재료학회지
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• 제21권5호
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• pp.268-272
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• 2011

Due to their novel properties, GaN based semiconductors and their nanostructures are promising components in a wide range of nanoscale device applications. In this work, the gallium nitride is deposited on c-axis oriented sapphire and porous SWCNT substrates by molecular beam epitaxy using a novel single source precursor of $Me_2Ga(N_3)NH_2C(CH_3)_3$ with ammonia as an additional source of nitrogen. The advantage of using a single molecular precursor is possible deposition at low substrate temperature with good crystal quality. The deposition is carried out in a substrate temperature range of 600-750$^{\circ}C$. The microstructural, structural, and optical properties of the samples were analyzed by scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and photoluminescence. The results show that substrate oriented columnar-like morphology is obtained on the sapphire substrate while sword-like GaN nanorods are obtained on porous SWCNT substrates with rough facets. The crystallinity and surface morphology of the deposited GaN were influenced significantly by deposition temperature and the nature of the substrate used. The growth mechanism of GaN on sapphire as well as porous SWCNT substrates is discussed briefly.