http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
분자선에피를 이용한 $In_{0.2}Ga_{0.8}N/GaN$ 이종접합구조의 성장에 미치는 플라즈마의 영향
심규환,Shim Kyu-Hwan 한국진공학회 2005 Applied Science and Convergence Technology Vol.14 No.2
분자선에피를 이용한 $In_{0.2}Ga_{0.8}N/GaN$ 이종접합 구조의 에피성장에 미치는 플라즈마의 rf전력의 영향에 대해 고찰하였다. 플라즈마를 발생시키는 rf 전력과 플라즈마 챔버압력의 조건에 따라 성장표면에 도달하는 분자나 원자의 에너지와 flux가 조절되어 에피성장 속도와 물질적 특성을 변화시킨다. 전력이 너무 낮거나 높은 조건에서 표면거칠기와 광특성이 각각 저하된 결과를 보였으며, 적정한 전력인 400W에서 성장한 $In_{0.2}Ga_{0.8}N/GaN$이 종접합 구조에서 날카로운 계면과 강한 photoluminescence 피크를 보였다. 이러한 현상에 대한 원인으로 고에너지 입자들이 성장표면에서 작용하는 기구들인 플라즈마에 의한 탈착과 표면확산, 성장표면의 하부에 주입되는 결함의 발생에 대하여 논하였다. The influence of plasma parameters on the growth of $In_{0.2}Ga_{0.8}N/GaN$ heterostructures has been investigated using plasma-assisted molecular beam epitaxy. Since plasma ejects plenty of energetic particles with different energy levels and flux density at various rf power levels, plasma modulated both growth rate and optical properties significantly. For instance, surface roughness and the emission spectrum of photoluminescence were degraded at low and high rf power. According to sharp interfaces between epitaxial films and strong peaks observed from photoluminescence spectra, our experimental setup presented optimal operation range of rf powers at around 400W. The phenomena could be explained by the presence of energetic particles modulating the rate of plasma stimulated desorption and surface diffusion, and energetic particles exceeding critical value resulted in the incorporation of defects at subsurface. The optimal rf power regime increased by 100W for $In_{0.2}Ga_{0.8}N/GaN$ growth in comparison with GaN. The effects of rf power were discussed in conjunction with kinetic processes being stimulated by energetic particles.
감압화학증착법으로 성장된 실리콘-게르마늄 반도체 에피층에서 붕소의 이차원 도핑 특성
심규환,Shim, Kyu-Hwan 한국전기전자재료학회 2004 전기전자재료학회논문지 Vol.17 No.12
Reduced pressure chemical vapor deposition(RPCYD) technology has been investigated for the growth of SiGe epitaxial films with two dimensional in-situ doped boron impurities. The two dimensional $\delta$-doped impurities can supply high mobility carriers into the channel of SiGe heterostructure MOSFETs(HMOS). Process parameters including substrate temperature, flow rate of dopant gas, and structure of epitaxial layers presented significant influence on the shape of two dimensional dopant distribution. Weak bonds of germanium hydrides could promote high incorporation efficiency of boron atoms on film surface. Meanwhile the negligible diffusion coefficient in SiGe prohibits the dispersion of boron atoms: that is, very sharp, well defined two-dimensional doping could be obtained within a few atomic layers. Peak concentration and full-width-at-half-maximum of boron profiles in SiGe could be achieved in the range of 10$^{18}$ -10$^{20}$ cm$^{-3}$ and below 5 nm, respectively. These experimental results suggest that the present method is particularly suitable for HMOS devices requiring a high-precision channel for superior performance in terms of operation speed and noise levels to the present conventional CMOS technology.
저에너지 광이온선(Broad Ion Beam)을 이용한 건식식각 및 박막증착
심규환,최영규,양전욱,강진영,Sim, Gyu-Hwan,Choi, Young-Kyu,Yang, Jeon-Wook,Kang, Jin-Young 한국전자통신연구원 1991 전자통신 Vol.13 No.2
저에너지 광이온선 (broad ion beam) 을 이용한 건식식각과 박막증착에 있어서 이온선 및 증착의 조건들에 따른 영향을 살펴보았다. 저에너지 광이온선은 화합물반도체 공정 및 고융점금속의 증착, optical coating, cosputter 에 의한 초전도물질합성 등 사용범위가 넓다. 단일이온선증착과 cosputter 의 경우에 근사수식과 실험치로서 증착비 및 막의 균일도를 최적화하는 target, 웨이퍼, 이온원 사이의 기계적 설계에 대해 고찰하였다. 저에너지 이온선의 이온과 target 원자 그리고 스퍼터된 이온과 시편원자와의 물리적, 화학적 반응기구는 반응성 이온과 보조 이온선 등의 다양한 기술에 응용될 수 있을 것으로 기대된다.
심규환,김승찬,윤영철,성영희,An Seong Soo A. 대한독성 유전단백체 학회 2020 Molecular & cellular toxicology Vol.16 No.4
Background Lewy bodies are pathological hallmarks for the diagnosis of Parkinson’s disease, where the core components are composed of aggregated forms of α-synuclein (α-syn). Although α-syn has been investigated as a potential biomarker for PD, its usage has been limited and still remains controversial. Objective An accurate enzyme-linked immunosorbent assay (ELISA) was developed for the detection of α-syn in plasma. The hemolysis score was calculated to eliminate the additive α-syn levels from RBCs. Human plasma samples were collected in heparinized blood tubes from idiopathic Parkinson disease (IPD) and healthy control (HC). Result Hemolysis score had a strong correlation with the level of plasma α-syn. From the limited set of samples in this preliminary study, decreased α-syn concentrations were observed in patients with IPD in comparison to HC after adjusting for hemolysis factor. Similar results with a commercial ELISA kit were found for measuring α-syn from the same set of samples with lower correlation and the reduced accuracy of diagnosis than the current study. Conclusion The adjustments for the hemolysis factor would be indispensable, supporting plasma α-syn as a potential surrogate biomarker for distinguishing IPD from HC.