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To estimate the optics lifetime of an extreme ultraviolet lithography (EUVL) system with a contaminated mirror surface, it is indispensable to carry out an acceleration test using high-flux EUV irradiation. In this study, Mo/Si multilayer mirrors were irradiated in various vacuum environments using a contamination evaluation system with an undulator light source, and changes in their reflectivity were evaluated. The dependence of the decrease in reflectivity per unit dose on the EUV irradiance was observed in high-flux irradiation experiments in vacuum with water vapor or n-decane gas introduction at pressures lower than about 10-5 Pa. The irradiance dependence disappeared when the pressures were increased for both water vapor and decane gas. A reflectivity distribution with a doughnut shape, namely, high at the irradiation center, low in the surrounding area, and high in the non-irradiated area, was observed in the irradiation experiments during the simultaneous introduction of water vapor and decane gas. These results can be generally explained by the mechanism of the supply-controlled limit.

Biosensing platforms based on functionalized superparamagnetic beads acting as “magnetic-labels” show tremendous potential for rapid and highly-sensitive point of care medical diagnosis. Recently, for greater quantification, there are increasing demands for the use of magnetic labels with diameters of 8–150 nm, which are comparable in size to actual biomolecules. However, detection of small numbers of sub-150 nm sized magnetic beads by magnetoresistive device-based platforms is extremely challenging due to the intrinsic noise of these electronic devices. Here, we describe an easy and economical detection method of low areal densities of 8-nm-diameter superparamagnetic “target beads” immobilized over millimeter-sized substrates by optically monitoring the magnetically induced “capture” of easily visible, micrometer sized superparamagnetic “columnar beads” by the targets in less than a few tens of seconds.

A new linewidth measurement system is developed using the environmental scanning electron microscope (ESEM) technology. The system shows good performance for a deep submicron device metrology tool. Here we will describe outlines of the system and some results of linewidth measurement and hole observation.