Spatially Resolved Spectroscopic Extreme Ultraviolet Reflectometry for Laboratory Applications

J Nanosci Nanotechnol. 2019 Jan 1;19(1):562-567. doi: 10.1166/jnn.2019.16470.

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.