Se-Jin Yook

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In extreme ultraviolet lithography (EUVL), conventional pellicles are unavailable for protecting the EUVL masks, since they highly absorb the EUV radiation. One of the serious challenges is therefore to prevent particulate contamination of the EUVL masks. In this paper, EUVL mask protection schemes proposed by Asbach were experimentally challenged against(More)
A cooling system, consisting of a chimney and a radial heat sink, was developed for a light-emitting diode (LED) downlight to replace a conventional light for saving energy. Natural convection was simulated with a numerical model that was verified experimentally. When the chimney was installed around the radial heat sink, the cooling efficiency of the heat(More)
A 3D computational electromagnetic-thermal coupled analysis was performed to analyze the effects of auxiliary cooling fans, called air-gap fans, on winding cooling in a large-capacity, high-speed induction motor. A novel non-uniform iron loss distribution mapping method considering time and rotation period was introduced to provide more accurate thermal(More)
Particulate contamination of masks is a serious challenge in extreme ultraviolet lithography (EUVL) technology due to the unavailability of conventional pellicles. EUVL mask surface inspection tools, operated at low pressure, are used not only for mask contamination control/monitoring but also for mask surface cleaning studies. In EUVL, contaminant(More)
Extreme ultraviolet lithography (EUVL) is considered the next generation lithography to produce 32-nm feature-size or smaller. The challenge is that conventional pellicles are unavailable for protecting the EUVL masks against contaminant particles, because the EUV beam is easily absorbed by most solid materials. The masks are usually transported or stored(More)
In this study, a hollow cylindrical tube with a coating layer on its inner wall was considered. The thermal resistance network method was employed to solve the heat conduction in the tube. Unknown heat flux on the inner wall of the tube was estimated from measured temperature on the outer wall of the tube by the recursive input estimation algorithm(More)
Many researchers who use laboratory-scale synthesis systems to manufacture nanomaterials could be easily exposed to airborne nanomaterials during the research and development stage. This study used various real-time aerosol detectors to investigate the presence of nanoaerosols in a laboratory used to manufacture titanium dioxide (TiO2). The TiO2 nanopowders(More)
Extreme ultraviolet lithography (EUVL) masks are vulnerable to particulate contamination due to the unavailability of pellicles. Particle deposition velocity is used to assess the level of particulate contamination. The particle deposition velocity onto a circular disk or a square flat plate situated perpendicular to the airflow was investigated. The(More)
The unintended influence of exhaust plumes emitted from a vehicle ahead to on-road air quality surveying data measured with a mobile laboratory (ML) at 20-40 km h-1 in dense traffic areas was investigated by experiment and life-sized computational fluidic dynamics (CFD) simulation. The ML equipped with variable sampling inlets of five columns by four rows(More)
Deposition velocity of charged particles onto a horizontal flat plate in parallel airflow in the presence of an electric field was numerically investigated by employing a Lagrangian particle tracking approach. The plate length was set as 450 mm, i.e., the characteristic length of the next generation wafer. Either the face-up or the face-down critical(More)
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