High contrast 3D imaging of surfaces near the wavelength limit using tabletop EUV ptychography

Ultramicroscopy. 2015 Nov;158:98-104. doi: 10.1016/j.ultramic.2015.07.006. Epub 2015 Jul 22.

Abstract

Scanning electron microscopy and atomic force microscopy are well-established techniques for imaging surfaces with nanometer resolution. Here we demonstrate a complementary and powerful approach based on tabletop extreme-ultraviolet ptychography that enables quantitative full field imaging with higher contrast than other techniques, and with compositional and topographical information. Using a high numerical aperture reflection-mode microscope illuminated by a tabletop 30 nm high harmonic source, we retrieve high quality, high contrast, full field images with 40 nm by 80 nm lateral resolution (≈1.3 λ), with a total exposure time of less than 1 min. Finally, quantitative phase information enables surface profilometry with ultra-high, 6 Å axial resolution. In the future, this work will enable dynamic imaging of functioning nanosystems with unprecedented combined spatial (<10 nm) and temporal (<10 fs) resolution, in thick opaque samples, with elemental, chemical and magnetic sensitivity.

Keywords: Coherent diffraction imaging; High harmonic generation; Reflection mode; Surface profilometry; X-ray microscopy.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.