• 한국전기전자재료학회논문지
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• 제22권8호
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• pp.654-658
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• 2009

For investigation of surface leakage currrent of AlGaN/GaN heterostructures through etched GaN buffer surface and mesa wall, three kind of surface-leakage-test-patterns were fabricated. and we measured the surface leakage current of each patterns. In result of our work, the surface leakage current of pattern of which Schottky contact is formed on etched mesa wall is the largest. the leakage current through schottky contact on etched mesa wall is predominant in AlGaN/GaN heterostructures.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
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• pp.299-302
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• 1995

Recently, we proposed a 3-D range-image measuring system for a slowly moving object by mechanically scanning a laser light beam emitted from a self mixing laser diode. In this paper, we introduced that every object moves along a straight line course, which is set diagonally against the semiconductor laser beam so that we can recognize each shape and size parameters of objects separately from the acquired 3-D range-image. We measured a square mesa on a square plane as an object. The measured velocity was 4.44mm/s and 4.63mm/s with an error of 0.56mm/s to 0.37mm/s. And thickness error of the mesa was 0.5mm to 0.6mm, which was obtained from the 3-D range-image of the standstill or moving object with thickness of 17.Omm.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 춘계학술대회 논문집
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• pp.89-90
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• 2009

Three kind of surface-leakage-test-patterns were fabricated and measured in order to investigate the surface leakage current of AlGaN/GaN heterostructures through etched GaN buffer surface and mesa wall. The pattern which contain the mesa wall has the largest surface leakage current among them. The leakage current due to the mesa wall is predominant source of the leakage current of AlGaN/GaN devices.

• TTA 저널
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• 통권87호
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• pp.191-200
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• 2003

• 전자공학회논문지A
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• 제31A권1호
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• pp.71-76
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• 1994

Schottky diodes have been fabricated using the SDB wafer, and their characteristics have been investigated. For comparison, conventional planar and etched most structure were made on the same substrate. The ideality factor and barrier height of the fabricated devices are found to be 1.03 and 0.77eV, respectively. Breakdown volttge of the etched mesa Schottky diode has been increased to 180V. whereas it is 90V for the planar diode. Schottky diode with an etched mesa exhibits twice improvement in breaktown voltage.

• 방재와보험
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• 통권103호
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• pp.72-74
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• 2004

• Clinical and Experimental Reproductive Medicine
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• 제21권3호
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• pp.267-272
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• 1994

We studied the role of assisted fertilization(subzonal insemination, intracytoplasmic sperm injection) in enhancing fertilization and pregnancy rate in obstructive azoospermia. MESA was performed in the patients with congenital absence of the vas deferens and unreconstructable obstructive azoospermia. Sperm were aspirated microsurgically from various sites along the epididymal stump. Sperm were then washed on a mini-PercoH gradient or swim-up method and treated by 2-deoxyadenosine and pentoxifylline. Conventional IVF(group I, 14 cycles), SUZI(group II, 13 cycles) and ICSI(gruop III, 28 cycles) were carried out in 55 treatment cycles. The clinical results are as follows: 1. Fertilization rates for group I, II and III were 16.1 %,31.4% and 48.6%, retrospectively (p<0.05). 2. Clinical pregnancy rates for group I, II and III were 7.1 %,7.7%, and 32.1 'Yo, retrospectively. 3. In 5 of MESA-ICSI cycles, epididymal sperm from alloplastic spermatocele were used and 2 clinical pregnancies (40%) were obtained. According to our results the combined MESA-ICSI procedure is highly effcient in improving fertilization and pregnancy rate in congenital absence of the vas deferens and unreconstructable obstructive azoospermia.

• 디지털융복합연구
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• 제19권11호
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• pp.341-349
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• 2021

최근 조명 산업이 중요한 분야로 인식되면서 PQR (Photonic Quantum Ring) 소자는 LED(Light Emitting Diode)를 대체할 수 있는 차세대 광원이 될 전망이다. 본 연구에서는 기존 연구와 유사한 결과를 검증하고, 소자의 광특성을 분석하기 위해 광섬유가 연결된 스테이지에 x, y, z 좌표를 입력하면 자동으로 이동하며, 또한, 소자에 광섬유를 근접시키는 NSOM (Near field scanning optical microscopy) 장치를 추가한 측정 시스템을 이용하여 소자의 광특성 실험과 공진 및 어레이 소자의 광특성 시뮬레이션을 통해 조명용 소자로 가능성을 검증하고자 하였다. 이를 위해 메사와 홀 형태가 동시에 존재하는 메사 직경 40㎛, 홀 직경 3㎛의 소자를 제작하여 소자의 근접장으로 PQR 소자는 ㎂에서 동작하며, 메사와 홀 소자는 서로 독립적으로 구동됨을 관찰하였다. 위치에 따른 소자의 광파장 스펙트럼을 측정하여 메사와 홀 소자에 의한 커플링 현상을 처음으로 확인하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 영호남학술대회 논문집
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• pp.25-28
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• 2000

A capacitance-type humidity sensors in which porous silicon layer is used as humidity-sensing material was developed. This sensors was fabricated monolithically to be compatible with the typical IC process technology except for the formation of porous silicon layer. As the sensors is made as a mesa structure, the correct measurement of capacitance is expected because it can remove the effect of the parasitic capacitance from the bottom layer and another junctions. To do this, the sensor was fabricated using process steps such as localized formation of porous silicon, oxidation of porous silicon layer and etching of oxidized porous silicon layer. From completed sensors, capacitance response was measured on the relative humidity of 25 to 95% at room temperature. As the result the measured capacitance showed the increase over 300% at the low frequency of 120Hz, and showed little dependence on the temperature between 10 to $40^{\circ}C$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.286-289
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• 2003

In the case of high voltage devices, junction termination plays an important role in determining the breakdown voltage of the device. The mesa junction termination has been demonstrated to yield nearly ideal breakdown voltage for 6H-SiC p-n junctions. However, such an approach may not be attractive because of the nonplanar surface, which is difficult to passivate. Moreover, In case of 4H-SiC, ideal breakdown voltage could not be achieved using mesa junction termination. For 4H-SiC planar junction termination technique is more useful one rather than mesa junction termination. In this paper, breakdown characteristics of the 4H-SiC device with planar junction termination, such as FLR(Field Limiting Ring), FP(Field Plate) and JTE(Junction Termination Extension), is presented. In the case of the FLR, breakdown voltage of 1800V is obtained. And breakdown voltage of 1000V and 1150V is also obtained for the case of FP and JTE case, respectively.