• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.97-98
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• 2005

양성자 조사법에 의하여 고속 전력용 다이오드를 제작하기 위하여 punch-through 다이오드에 다양한 조건으로 양성자를 조사하였다. 동일한 소자에 전자선을 조사한 소자와 속도 향상을 위한 공정이 행하여지지 않은 동일한 소자 각각의 특성을 비교 분석하였다. 양성자 주입은 주입 에너지를 1 MeV 와 1.3 MeV로, 각 에너지 조건에서 도즈를 $1\times10^{12}cm^{-2}$, $1\times10^{13}cm^{-2}$로 변화 시켰다. 분석 결과 양성자 주입된 소자에서 역방향 회복시간은 최소 소자의 약 45%, 전자선이 조사된 소자에 비하여 약 73 %의 값으로 향상시킬 수 있었으며 역방향 항복 전압과 순방향 저항은 처리되지 않은 소자와 전자빔이 조사된 시편들의 값과 비슷한 값을 나타내었다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.19-20
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• 2005

고속 동작 다이오드를 제작하기 위해 Non punch trough 형 실리콘 pn 다이오드에 다양한 조건으로 양성자를 주입하고 조건에 따른 소자의 전류-전압 특성을 분석했다. 양성자 주입은 에너지를 2.32Mev, 2.55Mev, 2.97Mev 로 또, 각 에너지 조건에서 도즈를 $1\times10^{11}cm^{-2}$, $1\times10^{12}cm^{-2}$, $1\times10^{13}cm^{-2}$로 변화 시키며 수행했다. 분석 결과, 순방향 전류 5A에서 전압 강하는 1.1V로 주입하지 않은 최초 소자의 122%로 증가하였으며 역방향 항복전압은 양성자를 주입하지 않은 소자와 비슷한 값을 보였다. 소자의 역방향 회복시간은 50nsec로써 최초 소자의 20% 수준으로 감소했다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.41-44
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• 2004

양성자 주입 기술을 pn 다이오드의 동작 속도를 향상시키기 위한 방법 이용하였다. 양성자 주입은 에너지를 2.32 MeV, 2.55 MeV, 2.97 MeV로 변화시키며 수행하여, projection 범위를 각각 접합, 공핍, 중성영역에 위치하도록 하였다. 또한 각각의 에너지 조건에서 도즈를 $1{\times}10^{11}\;cm^{-2}\;1{\times}10^{12}\;cm^{-2},\;1{\times}10^{13}\;cm^{-2}$의 세가지 조건으로 변화시켰다. 양성자 주입 조건 변화에 따른 소자 동작특성의 변화를 관찰하기 위하여 소자의 전류-전압 특성, 용량-전압 특성, 역방향 회복시간 측정을 수행하였다. 분석결과 양성자를 주입하지 않은 소자에 비해 특성의 큰 열화없이 역방향 회복시간을 약 1/5 수준으로 단축시킬 수 있는 것으로 나타났다.

• Journal of the Korean Vacuum Society
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• v.13 no.1
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• pp.1-8
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• 2004

The SOI wafer fabrication technique has been developed by using ion-cut process, based on proton implantation and wafer bonding techniques. It has been shown by TRIM simulation that 65 keV proton implantation is required for the standard SOI wafer (200 nm SOI, 400 nm BOX) fabrication. In order to investigate the optimum proton dose and primary annealing condition for wafer splitting, the surface morphologic change has been observed such as blistering and flaking. As a result, effective dose is found to be in the 6∼$9\times10^{16}$ $H^{+}/\textrm{cm}^2$ range, and the annealing at $550^{\circ}C$ for 30 minutes is expected to be optimum for wafer splitting. The depth distribution of implanted hydrogen has been experimentally confirmed by ERD and SIMS measurements. The microstructure evolution in the damaged layer was also studied by X-TEM analysis.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.112-112
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• 2004

양전자 단층촬영(PETㆍ Positron Emission Tomography)에 가장 널리 사용되는 방사성의약품인 FDG는 방사성동위원소인$^{18}$ F가 사용되며, 이는 안정물질인 H$_2$$^{18}$ O을 액체표적에 주입한 후, 고 에너지의 양성자빔을 조사하여 생산한다. 표적은 내화학성 및 높은 인장강도론 가진 재질인 titanium으로 제조하며, 0.075mm의 얇은 박판이 양성자빔 입사부에 사용된다. H$_2$$^{18}$ O가 주입된 표적에 양성자빔이 입사되는 순간 표적 내부는 높은 에너지로 인하여 표적물은 고온상태로 기화가 일어나고 이것이 압력을 증가시켜 target window는 바깥쪽으로 팽창한다.(중략)

• Proceedings of the Korean Vacuum Society Conference
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• 2004.08a
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• pp.119-119
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• 2004

• Proceedings of the Korean Vacuum Society Conference
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• 2004.08a
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• pp.123-124
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• 2004

• Applied Chemistry for Engineering
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• v.21 no.4
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• pp.401-404
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• 2010

The ion-beam induced changes in the characteristics of gadolinium doped ceria (GDC) pellets have been studied by UV-visible spectroscopy (UV-vis), SEM, and XRD. Implanted ions were protons or Xe ions with the energy of 120 keV or 5 MeV. Densely sintered pristine GDC pellets have cubic fluorite structure and are brown in color. As the ion irradiation proceeded, its color gradually turned into light black and finally into dark black. XRD patterns of GDC pellets were closely related with ion energy and the penetration depth of X-ray. It showed that upon the ion irradiation (120 keV) the lattice parameter of the cubic fluorite phase just beneath the surface is increased.

• Journal of the Korean Vacuum Society
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• v.14 no.2
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• pp.91-96
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• 2005

The silicon-on-insulator (SOI) wafer fabrication technique has been developed by using ion-cut process, based on proton implantation and wafer bonding techniques. It has been shown by SRIM simulation that 65keV proton implantation is required for a SOI wafer (200nm SOI, 400nm BOX) fabrication. In order to investigate the optimum proton dose and primary annealing condition for wafer splitting, the surface morphologic change has been observed such as blistering and flaking. As a result, effective dose is found to be in the $6\~9\times10^{16}\;H^+/cm^2$ range, and the annealing at $550^{\circ}C$ for 30 minutes is expected to be optimum for wafer splitting. Direct wafer bonding is performed by joining two wafers together after creating hydrophilic surfaces by a modified RCA cleaning, and IR inspection is followed to ensure a void free bonding. The wafer splitting was accomplished by annealing at the predetermined optimum condition, and high temperature annealing was then performed at $1,100^{\circ}C$ for 60 minutes to stabilize the bonding interface. TEM observation revealed no detectable defect at the SOI structure, and the interface trap charge density at the upper interface of the BOX was measured to be low enough to keep 'thermal' quality.

• Neonatal Medicine
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• v.15 no.1
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• pp.22-31
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• 2008

Purpose : Bronchopulmonary dysplasia (BPD) is characterized by arrested vascular and alveolar growth in the premature lung. Considering the consequences of arrested lung growth, the idea of administering bone marrow cells to enhance the inborn repair mechanism is promising as this may reduce the morbidity and mortality of BPD. We followed enhanced green fluorescent protein (EGFP)-labeled bone marrow cells (BMC) injected intraperitoneally into non-EGFP mice in order to determine their fate after transplantation. Methods : An angiogenesis inhibitor, SU1498, was injected subcutaneously on day 3 in non-EGFP C57BL/6 newborn mice to create a model of arrested alveolar development. On the following day, $1{\times}10^6$ BMCs isolated from major histocompatibility complex (MHC)- matched syngenic EGFP mice were injected intraperitoneally to non-EGFP BPD mice. Morphometric analysis, immunostaining, and confocal microscopy were performed to determine the fate of EGFP-positive stem cells in the injured lung. Results : SU1498 injection reduced alveolar surface area and mean alveolar volume in newborn mice. BMC injection resulted in recovery of lung structure comparable to controls. EGFP-positive BMCs were identified in the lungs of the recipient mice after intraperitoneal injection. The injected EGFP cells were co-stained with endothelial and epithelial cells of the developing lung as determined by confocal microscopy. Conclusion : Our results illustrated that EGFP-positive BMCs engrafted and trans-differentiated into epithelial and endothelial cells after intraperitoneal injection in a mouse model of arrested alveolar development.