ABSTRACT
Spatially resolved extreme ultraviolet reflectometry is presented in application to a local characterization of thin non-uniform contamination layers. Sample reflectivity mapping is performed, demonstrating high chemical sensitivity of the technique. Amorphous Al2O3 and carbon are determined as the contaminants of the studied silicon wafer. The results correlate with those obtained by energy-filtering photoemission electron microscopy. A laboratory tool is developed that is capable of multi-angle (2°-15°) and spectrally broadband (9.5-17 nm) extreme ultraviolet reflectometry at grazing incidence combined with a reduced sample illumination spot size, enabling spatially resolved metrology. A minimum EUV spot size of 25×30 µm in the sample plane is achieved experimentally.
ABSTRACT
In this Letter, the authors present a design study on YAG:Ce scintillator plates with a microstructured and coated surface. The goal of the study is to improve the outcoupling efficiency and to optimize the directionality of the scintillation light with respect to indirect image detection in the extreme ultraviolet spectral range (5-50 nm wavelength). In a geometric optical simulation, a gain in outcoupling efficiency by over a factor of 4 is shown while the directionality of the scintillation light is improved with respect to state-of-the-art plane scintillator plates.
ABSTRACT
We propose a model for the propulsion of Leidenfrost solids on ratchets based on viscous drag due to the flow of evaporating vapor. The model assumes pressure-driven flow described by the Navier-Stokes equations and is mainly studied in lubrication approximation. A scaling expression is derived for the dependence of the propulsive force on geometric parameters of the ratchet surface and properties of the sublimating solid. We show that the model results as well as the scaling law compare favorably with experiments and are able to reproduce the experimentally observed scaling with the size of the solid.