• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.13-18
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• 2004

전력계통 분야에서는 HVDC 전력변환소, BTB, UPFC 및 SVC의 안정성 향상 및 안정적인 운용을 위한 체계적인 유지보수 및 관리가 필요하다. 특히 전력계통에 접속된 대용량 전력반도체 소자인 사이리스터 밸브는 운전중에 열적, 전기적인 스트레스를 받게 되며, 이로 인해 밸브의 수명이 감소하여 전력계통의 안정적인 운용을 어렵게 만드는 요인이 된다. 따라서 전력계통 운용의 안정성을 확보하기 위해서는 대용량 사이리스터 밸브의 열적, 전기적 스트레스에 따른 수명 변화를 예측하는 열화진단 기법의 개발이 중요하다. 본 고에서는 대용량 사이리스터 소자의 열화진단 기법에 대한 국내외 현황과 현재 연구가 진행중인 열화 진단 기법에 대해 서술하였으며, 1500V급 사이리스터 소자의 가속열화 실험을 통해 소자의 수명을 예측한 결과를 나타내었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.95-95
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• 2008

본 연구에서는 SiGe p-MOSFET을 제작하여 I-V 특성과 게이트 길이, $V_D$, $V_G$의 변화에 따른 저주파 노이즈특성을 측정하였다. Si 기판위에 성장한 $Si_{0.88}Ge_{0.12}$으로 제작된 SiGe p-MOSFET의 채널은 게이트 산화막과 20nm 정도의 Si Spacer 층으로 분리되어 있다. 게이트 산화막은 열산화에 의해 70$\AA$으로 성장되었고, 게이트 폭은 $25{\mu}m$, 게이트와 소스/드레인 사이의 거리는 2.5때로 제작되었다. 제작된 SiGe p-MOSFET은 빠른 동작 특성, 선형성, 저주파 노이즈 특성이 우수하였다. 제작된 SiGe p-MOSFET의 ESD 에 대한 소자의 신뢰성과 내성을 연구하기 위하여 SiGe P-MOSFET에 ESD를 lkV에서 8kV까지 lkV 간격으로 가한 후, SiGe P-MOSFET의 I-V 특성과 게이트 길이, $V_D$, $V_G$의 변화에 따른 저주파 노이즈특성 변화를 분석 비교하였다.

• 한국전기전자재료학회논문지
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• 제28권4호
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• pp.218-221
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• 2015

Power MOSFETs (metal oxide semiconductor field effect transistor) operate as energy control semiconductor switches. In order to reduce energy loss of the device during switch-on state, it is essential to increase its conductance. In this study we have investigated a structure to reduce the on-resistance characteristics of the MOSFET. We have a proposed MOSFET structure of active cells region buried under the gate pad. The measurement are carried out with a EDS to analyze electrical characteristics, and the proposed MOSFET are compared with the conventional MOSFET. The result of proposed MOSFET was 1.68[${\Omega}$], showing 10% improvement compared to the conventional MOSFET at 700[V].

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.187-187
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• 2007

This paper presents the electrical properties of SiGe HBTs designed with bottom collector and single metal layer structure for RF power amplifier. Base layer was formed with graded-SiGe/Si structures and the collector place to the bottom of the device. Bottom collector and single metal layer structures could significantly simplify the fabrication process. We studied about the influence of SiGe base thickness, number of emitter fingers and temperature dependence (< $200^{\circ}C$) on electrical properties. The feasible application in 1~2GHz frequency from measured data $BV_{CEO}$ ~10V, $f_r$~14 GHz, ${\beta\simeq}110$, NF~1 dB using packaged SiGe HBTs. We will discuss the temperature dependent current flow through the e-b, b-c junctions to understand stability and performance of the device.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1996년도 제11회 학술발표회 논문개요집
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• pp.40-41
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• 1996

Nitridation technique has been receiving much attention for the formation of a thin nitrided buffer layer on which high quality nitride films can be formedl. Particularly, gallium nitride (GaN) has been considered as a promising material for blue-and ultraviolet-emitting devices. It can also be used for in situ formed and stable passivation layers for selective growth of $GaAs_2$. In this work, formation of a thin nitrided layer is investigated. Nitrogen electron cyclotron resonance(ECR)-plasma is employed for the formation of thin nitrided layer. The plasma source used in this work is a compact ECR plasma gun3 which is specifically designed to enhance control, and to provide in-situ monitoring of plasma parameters during plasma-assisted processing. Microwave power of 100-200 W was used to excite the plasma which was emitted from an orifice of 25 rnm in diameter. The substrate were positioned 15 em away from the orifice of plasma source. Prior to nitridation is performed, the surface of n-type (001)GaAs was exposed to hydrogen plasma for 20 min at $300{\;}^{\circ}C$ in order to eliminate a native oxide formed on GaAs surface. Change from ring to streak in RHEED pattern can be obtained through the irradiation of hydrogen plasma, indicating a clean surface. Nitridation was carried out for 5-40 min at $RT-600{\;}^{\circ}C$ in a ECR plasma-assisted molecular beam epitaxy system. Typical chamber pressure was $7.5{\times}lO^{-4}$ Torr during the nitridations at $N_2$ flow rate of 10 seem.(omitted)mitted)

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.355-356
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• 2008

In this work, ZnO films doped with different contents of Indium (0.1at.%, 0.3at.%, 0.6at.%, respectively) were deposited on Si (111) substrate that has 1~20 $\Omega$cm by pulsed laser deposition (PLD) at $600^{\circ}C$ for 30min. The thickness of the films are about 250 nm. The structural, optical and electrical properties of the films were investigated using X-ray Diffraction (XRD), Atomic force microscope (AFM), Photoluminescence (PL) and Hall measurement. It has been found that RMS of the films is decreased and grain size is increased with increasing the contents of doped Indium. The results of the Photoluminescence properties were indicated that the films have UV emission about 380nm and shows a little red shitf with increasing contents of doped indium. The result of the Hall measurement shows that the concentration and resisitivity in doped ZnO are as changing as one order, respectively ${\sim}10^{18}/cm^2$, ${\sim}10^{-2}cm{\Omega}cm$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.154-154
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• 2009

Cr capping layer를 이용하여 Titanium germanide의 열적 안정성을 향상시키는 연구를 수행하였다. n-type Ge(100) 기판 위에 전자빔 증착기를 이용하여 30nm 두께의 Ti와 Cr capping layer를 증착하고 $400\;^{\circ}C$에서 $800\;^{\circ}C$까지 30초간 N2 분위기로 급속 열처리하여 Ti germanide를 형성하였다. XRD결과로부터 Cr capping layer의 유무에 관계 없이 Ti germanide가 형성된 것을 관찰할 수 있었다. Ge 기판 위에 CTLM 패턴을 형성하고 실험을 진행하여 Ti germanide의 I-V 측정 데이터를 통해 Ohmic 특성을 알아보았고, contact resistance, sheet resistance, specific contact resistance를 구하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(I)
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• pp.549-552
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• 1987

TO INCREASE THE CELL CAPACITANCE Of SMALL GEOMETRY DRAMS. HIGH DIELECTRIC MATERIAL HAS BEEN USED RECENTLY. THE PURPOSE Of THIS WORK IS TO INVESTIGATE THE STRUCTURAL AND ELECTRICAL CHARACTERISTICS Of SiO2/Si3N4/SiO2 STACKED FILM UTILIZING HIGH DIELECTRIC MATERIAL Si3N4(${\epsilon}=7.5$). IN RESULT, THE DIELECTRIC CONSTANT Of STACKED FILM IS 4.0 - 5.0 AND CAPACITANCE AND BREAKDOWN FIELD WERE MORE INCREASED THAN THOSE Of SiO2 FILM.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.40-41
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• 2005

In this study, we proposed CMP micro-scratches generated by contaminative particle which existed on the wafer surface prior to CMP process. The CMP micro-scratches are one of the slurry abrasive related damage. To reduce the micro-scratches, research efforts have been devoted to the optimization of slurry abrasive size distribution. In addition of slurry abrasive, it was found that contaminative particles also were major CMP micro-scratch source.

• 대한산업공학회지
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• 제34권3호
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• pp.296-307
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• 2008

A semiconductor production system has sophisticated manufacturing operations and needs high capital investment for its expensive equipment, which warrants efficient real-time flow control for wafers. In the bay, we consider material handling equipment that can handle multiple carriers of wafers. The dispatching logic first determines the transportation time of each carrier to its destination by each unit of transportation equipment and uses this information to determine the destination machine and target carrier. When there is no available buffer space at the machine tool, the logic allows carriers to stay at the buffer of a machine tool and determine the delay time, which is used to determine the destination of carriers in URL. A simulation study shows this dispatching logic performs better than the procedure currently in use to reduce the mean flow time and average WIP of wafers and increase efficiency of material handling equipment.