We demonstrate hyperspectral coherent imaging in the EUV spectral region for the first time, without the need for hardware-based wavelength separation. This new scheme of spectromicroscopy is the most efficient use of EUV photons for imaging because there is no energy loss from mirrors or monochromatizing optics. An EUV spectral comb from a tabletop high-harmonic source, centered at a wavelength of 30nm, illuminates the sample and the scattered light is collected on a pixel-array detector. Using a lensless imaging technique known as ptychographical information multiplexing, we simultaneously retrieve images of the spectral response of the sample at each individual harmonic. We show that the retrieved spectral amplitude and phase agrees with theoretical predictions. This work demonstrates the power of coherent EUV beams for rapid material identification with nanometer-scale resolution.

Date Published: 21 April 2016
PDF: 7 pages
Proc. SPIE 9778, Metrology, Inspection, and Process Control for Microlithography XXX, 977808 (21 April 2016); doi: 10.1117/12.2220711

Published in SPIE Proceedings Vol. 9778:
Metrology, Inspection, and Process Control for Microlithography XXX
Martha I. Sanchez, Editor(s)