Pushing short wavelength imaging to the fundamental limits
Although x-ray imaging has been explored for decades, and visible-wavelength microscopy for centuries, it is only recently that the spectral region in between―the extreme ultraviolet (EUV)―has been explored for imaging nanostructures and nanomaterials. With the practical implementation of coherent EUV light sources based on high harmonic generation (HHG), combined with coherent diffractive imaging (CDI), it has been shown that EUV imaging has unique advantages. These advantages are important, because for synthesis and integration of a host of next-generation materials and nanostructures, new approaches are needed to non-destructively and routinely determine interfacial and layer structure as well as surface morphology, with sensitivity to dopant distributions and material composition.
In recent research, the first sub-wavelength imaging at short wavelengths using any light source, small or large has been demonstrated. This microscope achieved ~12 nm transverse and ~1 Å axial resolution. The first full field dynamic imaging microscope, with 10fs temporal resolution, is now a commercial offering under the KMLabs Quantum Microscope (QM) platform. The QM has an optional phase-sensitive EUV imaging reflectometer. It combines the excellent phase stability of coherent high harmonic sources with the unique chemical- and phase- sensitivity of EUV reflectometry, and with state-of-the-art ptychography imaging algorithms. This tabletop microscope can non-destructively probe surface topography, layer thicknesses, and interface quality, as well as dopant concentrations and profiles.
- Non-Destructive, High-Resolution, Chemically Specific, 3D Nanostructure Characterization using Phase-Sensitive EUV Imaging Reflectometry, M. Tanksalvala, C. Porter, Y. Esashi, G.Miley, N. Horiguchi, R. Karl, P. Johnsen, C. Bevis, N. Jenkins, B. Wang, X. Zhang, S. Cousin, D. Adams, M. Gerrity, H. Kapteyn, M. Murnane, submitted (2020).
- R. Karl, G. Mancini, J. Knobloch, T. Frazer, J. Hernandez-Charpak, B. Abad, D. Gardner, E. Shanblatt, M. Tanksalvala, C. Porter, C. Bevis, D. Adams, H. Kapteyn, M. Murnane, “Full-field imaging of thermal and acoustic dynamics in an individual nanostructure using tabletop high harmonic beams,” Science Advances 4, eaau4295 (2018). DOI: 10.1126/sciadv.aau4295
- G. Mancini, R. Karl, E. Shanblatt, C. Bevis, D. Gardner, M. Tanksalvala, J. Russell, D. Adams, H. Kapteyn, J. Badding, T. Mallouk, M. Murnane, “Colloidal Crystal Order and Structure Revealed by Tabletop Extreme Ultraviolet Scattering and Coherent Diffractive Imaging,” Optics Express 26(9) 11393–11406 (2018).
- C. Bevis, R. Karl Jr., J. Reichanadter, D. Gardner, C. Porter, E. Shanblatt, M. Tanksalvala, G. Mancini, H. Kapteyn, M. Murnane, D. Adams, “Multiple beam ptychography for large field of view, high throughput, quantitative phase contrast imaging,” Ultramicroscopy 184, 164–171 (2018).
- C. Porter, M. Tanksalvala, M. Gerrity, G. Miley, X. Zhang, C. Bevis, E. Shanblatt, R. Karl Jr., M. Murnane, D. Adams, H. Kapteyn, “General-purpose, wide field-of-view reflection imaging with a tabletop 13nm light source,” Optica 4(12) 1552–1557 (2017).
- D. Gardner, M. Tanksalvala, E. Shanblatt, X. Zhang, B. Galloway, C. Porter, R. Karl, C. Bevis, D. Adams, H. Kapteyn, M. Murnane, G. Mancini, “Sub-wavelength coherent imaging of periodic samples using a 13.5 nm tabletop high harmonic light source,” Nature Photonics 11, 259 (2017). doi:10.1038/nphoton.2017.33
- E. Shanblatt, C. Porter, D. Gardner, G. Mancini, R. Karl Jr., M. Tanksalvala, C. Bevis, H. Kapteyn, D. Adams, M. Murnane, “Imaging Buried Nanostructures using Extreme Ultraviolet Ptychographic Coherent Diffractive Imaging,” Nano Letters 16 (9), 5444–5450 (2016). DOI: 10.1021/acs.nanolett.6b01864
- Bosheng Zhang, Dennis Gardner, Matthew Seaberg, Elisabeth Shanblatt, Henry C. Kapteyn, Margaret M. Murnane, Daniel Adams, “High contrast 3D imaging of surfaces near the wavelength limit using tabletop EUV ptychography,” Ultramicroscopy 158, 98–104 (2015). Featured on Cover.
- J. Miao, T. Ishikawa, I. K. Robinson & M. M. Murnane, “Beyond Crystallography: Diffractive Imaging with Coherent X-ray Sources,” Science 348, 530 (2015). Featured on cover of Science.
- M.D. Seaberg, B. Zhang, D.F. Gardner, E.R. Shanblatt, M.M. Murnane, H.C. Kapteyn, D.E. Adams, “Tabletop Nanometer Extreme Ultraviolet Imaging in an Extended Reflection Mode using Coherent Fresnel Ptychography,” Optica 1, 39 (2014).
- B. Zhang, M. Seaberg, J. Shaw, D. Gardner, D. Adams, M. Murnane, H. Kapteyn, “Full field tabletop EUV coherent diffractive imaging in a transmission geometry,” Optics Express 21, 21970 (2013).
- R.L. Sandberg, D.A. Raymondson, C. La-o-vorakiat, A. Paul, K. Raines, J. Miao, M.M. Murnane, H.C. Kapteyn, B.F. Schlotter, “Closing the Gap to the Diffraction Limit: Tabletop Soft X-Ray Fourier Transform Holography with 50 nm Resolution,” Optics Letters 34, 1618 (2009).
- Richard Sandberg, Ariel Paul, Daisy Raymondson, Steffen Hädrich, David Gaudiosi, Jim Holtsnider, Ron Tobey, Oren Cohen, Margaret Murnane, Henry Kapteyn, Changyong Song, Jianwei Miao, Yanwei Liu, Farhad Salmassi, “Lensless diffractive imaging using coherent high harmonic beams,” Physical Review Letters 99, 098103 (2007).